MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'European Journal of Neuroscience' source. Tue, 07 Feb 2012 07:05:43 +0100 http://www.medworm.com/index.php?rid=5665084&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2012.07989.x AbstractIn many sensory systems adaptation acts as a gain control mechanism that optimizes sensory performance by trading increased sensitivity to low stimulus intensity for decreased sensitivity to high stimulus intensity. Adaptation of insect antennal olfactory receptor neurons (ORNs) has been studied for strong odour concentrations, either pulsed or constant. Here, we report that during slowly oscillating changes in the concentration of the odour of lemon oil, the ON and OFF ORNs on the antenna of the cockroach Periplaneta americana adapt to the actual odour concentration and the rate at which concentration changes. When odour concentration oscillates rapidly with brief periods, adaptation improves gain for instantaneous odour concentration and reduces gain for the rate of concentration... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665084 Mon, 06 Feb 2012 05:00:00 +0100 5665084 http://www.medworm.com/index.php?rid=5665083&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2012.08000.x This study was aimed at testing the hypothesis that the central nucleus of the amygdala (CeN) plays a critical role in such regulation. To this end, rats were trained to press a lever to self‐administer cocaine under a chained schedule: a response on one lever (cocaine‐seeking lever) led to access to the other lever (cocaine‐taking lever), on which a response was reinforced by cocaine and cues. Thereafter, responses on the seeking lever were punished by footshock with a probability of 0.5. Cocaine self‐administration (SA) was significantly suppressed by punishment in an intensity‐dependent manner. Interestingly, rats trained with daily 6‐h (extended access) but not 2‐h (limited access) sessions showed resistance to the lower intensity of punishment. Inactivation of the CeN in... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665083 Mon, 06 Feb 2012 05:00:00 +0100 5665083 http://www.medworm.com/index.php?rid=5665082&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07973.x AbstractIt has been suggested that unconscious visual processing of some stimulus features might occur without the contribution of early visual cortex (V1/V2). In the present study, the causal role of V1/V2 in unconscious processing of simple shapes in intact human brain was studied by applying transcranial magnetic stimulation (TMS) on early visual cortex or lateral occipital cortex (LO) while observers performed a metacontrast‐masked response priming task with arrow figures as visual stimuli. Magnetic stimulation of V1/V2 impaired masked priming 30–90 ms after the onset of the prime. Stimulation of LO reduced the magnitude of masked priming at 90–120 ms, but this effect occurred only in the early parts of the priming experiment. A control task measuring the visibility of masked... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665082 Mon, 06 Feb 2012 05:00:00 +0100 5665082 http://www.medworm.com/index.php?rid=5665081&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07988.x AbstractCalcium (Ca2+) is a major second messenger in the regulation of different forms of synaptic and intrinsic plasticity. Tightly organized in space and time, postsynaptic Ca2+ transients trigger the activation of many distinct Ca2+ signaling cascades, providing a means for a highly specific signal transduction and plasticity induction. High‐resolution two‐photon microscopy combined with highly sensitive synthetic Ca2+ indicators in brain slices allowed for the quantification and analysis of postsynaptic Ca2+ dynamics in great detail. Much of our current knowledge about postsynaptic Ca2+ mechanisms is derived from studying Ca2+ transients in the dendrites and spines of pyramidal neurons. However, postsynaptic Ca2+ dynamics differ considerably among different cell types. In particul... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665081 Mon, 06 Feb 2012 05:00:00 +0100 5665081 http://www.medworm.com/index.php?rid=5665080&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07976.x AbstractThe present study aimed to create a direct bridge between observations on peripheral and central responses to odorant mixtures and their components. Three experiments were performed using mixtures of fruity (isoamyl acetate; ISO) and woody (whiskey lactone; WL) odorants known to contribute to some of the major notes in Burgundy red wine. These experiments consisted of (i) calcium imaging of human embryonic kidney cells (HEK293T) transfected with olfactory receptors (ORs); (ii) single‐unit electrophysiological recordings from olfactory receptor neurons (ORNs) and analyses of electro‐olfactogram (EOG) responses in the rat nose in vivo; and (iii) psychophysical measurements of the perceived intensity of the mixtures as rated by human subjects. The calcium imaging and electrophysio... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665080 Mon, 06 Feb 2012 05:00:00 +0100 5665080 http://www.medworm.com/index.php?rid=5665086&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07975.x AbstractA novel class of photoreceptors, the intrinsically photosensitive retinal ganglion cells (ipRGCs), express the photopigment melanopsin and drive non‐image‐forming responses to light such as circadian photoentrainment, the pupillary light reflex and suppression of nocturnal melatonin production in the pineal. Because dendrites from one subclass of these cells – the M1‐type ipRGCs – make presumptive synaptic contacts at sites of dopamine release from dopaminergic amacrine cells, they are prime targets for modulation by dopamine, a neuromodulator implicated in retinal circadian rhythms and light adaptation. In patch‐clamp recordings from ipRGCs in intact rat retinas, dopamine attenuated the melanopsin‐based photocurrent. We confirmed that this was the result of direct ac... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665086 Sun, 05 Feb 2012 05:00:00 +0100 5665086 http://www.medworm.com/index.php?rid=5665085&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07977.x AbstractThe present study uses a double retrograde tracer technique in rats to examine the spatial localization and pattern of axonal branching in mossy fibres arising from three major sources in the medulla—the external cuneate nucleus, the sensory trigeminal nucleus and the reticular formation, to two electrophysiologically‐identified parts of the cerebellar cortex that are linked by common climbing fibre input – the forelimb‐receiving parts of the C1 zone in lobulus simplex and the paramedian lobule. In each experiment a small injection of rhodamine‐tagged beads was injected into one cortical region and an injection of fluorescein‐tagged beads was injected into the other region. The main findings were: (i) the proportion of double‐labelled cells in each of the three precer... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665085 Sun, 05 Feb 2012 05:00:00 +0100 5665085 http://www.medworm.com/index.php?rid=5657838&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07979.x AbstractMotor studies of Parkinson’s disease (PD) have shown cortical hypo‐activity in relation to nigrostriatal dopamine depletion. Cognitive studies also identified increased cortical activity in PD. We have previously suggested that the hypo‐activity/hyper‐activity patterns observed in PD are related to the striatal contribution. Tasks that recruit the striatum in control participants are associated with cortical hypo‐activity in patients with PD, whereas tasks that do not result in cortical hyper‐activity. The putamen, a structure affected by the neurodegeneration observed in PD, shows increased activation for externally‐triggered (ET) and self‐initiated (SI) movements. The first goal of this study was to evaluate the effect of levodopa on the putamen’s response to ET... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5657838 Fri, 03 Feb 2012 05:00:00 +0100 5657838 http://www.medworm.com/index.php?rid=5657839&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2012.07999.x AbstractThe antennal lobe (AL) is the first olfactory center of the insect brain and is constituted of different functional units, the glomeruli. In the AL, odors are coded as spatiotemporal patterns of glomerular activity. In honeybees, olfactory learning during early adulthood modifies neural activity in the AL on a long‐term scale and also enhances later memory retention. By means of behavioral experiments, we first verified that olfactory learning between the fifth and eighth day of adulthood induces better retention performances at a late adult stage than the same experience acquired before or after this period. We checked that the specificity of memory for the odorants used was improved. We then studied whether such early olfactory learning also induces long‐term structural chang... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5657839 Thu, 02 Feb 2012 05:00:00 +0100 5657839 http://www.medworm.com/index.php?rid=5665079&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07984.x In this study, differences in gene expression in the superior cervical ganglion of postnatal day (P)5, P10 and 6–7‐week‐old wild‐type and genetically dystrophic mdx mice were evaluated by DNA microarray analysis. The main aim was to verify whether the lack of dystrophin affected the transcript levels of genes related to different aspects of neuron development and differentiation. Ontological analysis of more than 500 modulated genes showed significant differences in genetic class enrichment at each postnatal date. Upregulated genes mainly fell in the categories of vesicular trafficking, and cytoskeletal and synaptic organization, whereas downregulated genes were associated with axon development, growth factors, intracellular signal transduction, metabolic processes, gene expression... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5665079 Wed, 01 Feb 2012 05:00:00 +0100 5665079 http://www.medworm.com/index.php?rid=5657837&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07974.x AbstractPrimary sensory cortices are traditionally regarded as stimulus analysers. However, studies of associative learning‐induced plasticity in the primary auditory cortex (A1) indicate involvement in learning, memory and other cognitive processes. For example, the area of representation of a tone becomes larger for stronger auditory memories and the magnitude of area gain is proportional to the degree that a tone becomes behaviorally important. Here, we used extinction to investigate whether ‘behavioral importance’ specifically reflects a sound’s ability to predict reinforcement (reward or punishment) vs. to predict any significant change in the meaning of a sound. If the former, then extinction should reverse area gains as the signal no longer predicts reinforcement. Rats (n ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5657837 Wed, 01 Feb 2012 05:00:00 +0100 5657837 http://www.medworm.com/index.php?rid=5645042&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07960.x AbstractA major feature of focal hand dystonia (FHD) pathophysiology is the loss of inhibition. One inhibitory process, surround inhibition, for which the cortical mechanisms are still unknown, is abnormal in FHD. As the ventral premotor cortex (PMv) plays a key role in the sensorimotor processing involved in shaping finger movements and has many projections onto the primary motor cortex (M1), we hypothesized that the PMv–M1 connections might play a role in surround inhibition. A paired‐pulse transcranial magnetic stimulation paradigm was used in order to evaluate and compare the PMv–M1 interactions during different phases (rest, preparation and execution) of an index finger movement in patients with FHD and controls. A sub‐threshold conditioning pulse (80% resting motor threshold)... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645042 Wed, 01 Feb 2012 05:00:00 +0100 5645042 http://www.medworm.com/index.php?rid=5645041&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07961.x AbstractThe effects of transcranial magnetic stimulation (TMS) on post‐discharge histograms of single motor units in the first dorsal interosseous have been tested to estimate the input–output properties of cortical network‐mediating short‐interval intracortical inhibition (SICI) to pyramidal cells of the human primary motor cortex. SICI was studied using the paired pulse paradigm (2‐ms interval): test TMS intensity was varied to evoke peaks of different size in post‐discharge histograms, reflecting the corticospinal excitatory post‐synaptic potential in the relevant spinal motoneuron, and conditioning TMS intensity was constant (0.6 × the resting motor threshold). Navigated brain stimulation was used to monitor the coil position. A linear relationship was observed between... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645041 Wed, 01 Feb 2012 05:00:00 +0100 5645041 http://www.medworm.com/index.php?rid=5645040&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07967.x AbstractDuring hunting, the barn owl typically listens to several successive sounds as generated, for example, by rustling mice. As auditory cells exhibit adaptive coding, the earlier stimuli may influence the detection of the later stimuli. This situation was mimicked with two double‐stimulus paradigms, and adaptation was investigated in neurons of the barn owl’s central nucleus of the inferior colliculus. Each double‐stimulus paradigm consisted of a first or reference stimulus and a second stimulus (probe). In one paradigm (second level tuning), the probe level was varied, whereas in the other paradigm (inter‐stimulus interval tuning), the stimulus interval between the first and second stimulus was changed systematically. Neurons were stimulated with monaural pure tones at the be... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645040 Wed, 01 Feb 2012 05:00:00 +0100 5645040 http://www.medworm.com/index.php?rid=5645039&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07971.x AbstractArcher fish are known for their unique hunting method, where one fish in a group shoots down an insect with a jet of water while all the other fish are observing the prey’s motion. To reap its reward, the archer fish must reach the prey before its competitors. This requires fast computation of the direction of motion of the prey, which enables the fish to initiate a turn towards the prey with an accuracy of 99%, at about 100 ms after the prey is shot. We explored the hypothesis that direction‐selective retinal ganglion cells may underlie this rapid processing. We quantified the degree of directional selectivity of ganglion cells in the archer fish retina. The cells could be categorized into three groups: sharply (5%), broadly (37%) and non‐tuned (58%) directionally selectiv... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645039 Wed, 01 Feb 2012 05:00:00 +0100 5645039 http://www.medworm.com/index.php?rid=5645038&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07968.x AbstractPatients suffering from major depression have repeatedly been reported to have dysregulations in hypothalamus–pituitary–adrenal (HPA) axis activity along with deficits in cognitive processes related to hippocampal and prefrontal cortex (PFC) malfunction. Here, we utilized three mouse lines selectively bred for high (HR), intermediate, or low (LR) stress reactivity, determined by the corticosterone response to a psychological stressor, probing the behavioral and functional consequences of increased vs. decreased HPA axis reactivity on the hippocampus and PFC. We assessed performance in hippocampus‐ and PFC‐dependent tasks and determined the volume, basal activity, and neuronal integrity of the hippocampus and PFC using in vivo manganese‐enhanced magnetic resonance imaging ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645038 Wed, 01 Feb 2012 05:00:00 +0100 5645038 http://www.medworm.com/index.php?rid=5645037&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2012.08004.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645037 Wed, 01 Feb 2012 05:00:00 +0100 5645037 http://www.medworm.com/index.php?rid=5645036&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07965.x AbstractIntracerebral injection of ibotenate into mouse pups induced grey matter lesions and white matter cysts; co‐administration of brain‐derived neurotrophic factor (BDNF) produced a dose‐dependent reduction in these lesions. In contrast, glial cell line‐derived neurotrophic factor (GDNF) had no significant effect, whereas nerve growth factor (NGF) or interleukin‐1β (IL‐1β) resulted in dose‐dependent exacerbation. The neuroprotective effects of BDNF were abolished by co‐administration of anti‐BDNF antibody or MEK inhibitors, or ABT‐737, a BH3 mimetic and Bcl‐2 antagonist. The actions of BDNF, GDNF and NGF were measured in a parallel in vitro study on the oxidative metabolism of mouse brain mitochondria. BDNF produced a concentration‐dependent increase in the re... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645036 Wed, 01 Feb 2012 05:00:00 +0100 5645036 http://www.medworm.com/index.php?rid=5645035&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07958.x This study is the first to demonstrate the requirement of CRP1a for zebrafish spinal cord regeneration.In contrast to mammals, adult zebrafish have the ability to regrow descending axons and gain locomotor recovery after spinal cord injury (SCI). In zebrafish, a decisive factor for successful spinal cord regeneration is the inherent ability of some neurons to regrow their axons via (re)expressing growth‐associated genes during the regeneration period. (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645035 Wed, 01 Feb 2012 05:00:00 +0100 5645035 http://www.medworm.com/index.php?rid=5645034&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07959.x AbstractInsulin and insulin‐like growth factor‐I play important roles in the development and maintenance of neurons and glial cells of the nervous system. Both factors activate tyrosine kinase receptors, which signal through adapter proteins of the insulin receptor substrate (IRS) family. Although insulin and insulin‐like growth factor‐I receptors are expressed in dorsal root ganglia (DRG), the function of IRS‐mediated signalling in these structures has not been studied. Here we address the role of IRS2‐mediated signalling in murine DRG. Studies in cultured DRG neurons from different embryonic stages indicated that a subset of nerve growth factor‐responsive neurons is also dependent on insulin for survival at very early time points. Consistent with this, increased apoptosis d... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5645034 Wed, 01 Feb 2012 05:00:00 +0100 5645034 http://www.medworm.com/index.php?rid=5626060&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07972.x AbstractAlthough multiple sclerosis (MS) has traditionally been considered to be an inflammatory disease, recent evidence has brought neurodegeneration into the spotlight, suggesting that accumulated damage and loss of axons is critical to disease progression and the associated irreversible disability. Proposed mechanisms of axonal degeneration in MS posit cytosolic and subsequent mitochondrial Ca2+ overload, accumulation of pathologic reactive oxygen species (ROS), and mitochondrial dysfunction leading to cell death. In this context, the role of the p66 isoform of ShcA protein (p66) may be significant. The ShcA isoform is uniquely targeted to the mitochondrial intermembrane space in response to elevated oxidative stress, and serves as a redox enzyme amplifying ROS generation in a positive... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626060 Wed, 25 Jan 2012 05:00:00 +0100 5626060 http://www.medworm.com/index.php?rid=5626059&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07969.x AbstractDopamine (DA) depletion of the posterior dorsomedial striatum (pDMS) can impair the capability of rats to detect changes in the causal efficacy of actions. Here we sought to characterize in more detail the effects of pDMS DA depletions on contingency detection as a function of different contingency degradation training protocols. In experiment 1, sham controls and rats with pDMS DA depletions received limited contingency degradation training (4 days) that involved an invariable and high degree of degradation to one of two contingencies controlling instrumental choice behaviour. The results demonstrated that lesioned rats were insensitive to contingency manipulations both during contingency degradation training and in the subsequent extinction test. Experiment 2 further indicated ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626059 Wed, 25 Jan 2012 05:00:00 +0100 5626059 http://www.medworm.com/index.php?rid=5626058&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07957.x AbstractRecent evidence supports an emerging role of β‐nicotinamide adenine dinucleotide (β‐NAD+) as a novel neurotransmitter and neuromodulator in the peripheral nervous system –β‐NAD+ is released in nerve‐smooth muscle preparations and adrenal chromaffin cells in a manner characteristic of a neurotransmitter. It is currently unclear whether this holds true for the CNS. Using a small‐chamber superfusion assay and high‐sensitivity high‐pressure liquid chromatography techniques, we demonstrate that high‐K+ stimulation of rat forebrain synaptosomes evokes overflow of β‐NAD+, adenosine 5′‐triphosphate, and their metabolites adenosine 5′‐diphosphate (ADP), adenosine 5′‐monophosphate, adenosine, ADP‐ribose (ADPR) and cyclic ADPR. The high‐K+‐evoked over... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626058 Wed, 25 Jan 2012 05:00:00 +0100 5626058 http://www.medworm.com/index.php?rid=5626057&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07970.x AbstractStem cells derived from the human brain and grown as neurospheres (HuCNS‐SC) have been shown to be effective in treating central neurodegenerative conditions in a variety of animal models. Human safety data in neurodegenerative disorders are currently being accrued. In the present study, we explored the efficacy of HuCNS‐SC in a rodent model of retinal degeneration, the Royal College of Surgeons (RCS) rat, and extended our previous cell transplantation studies to include an in‐depth examination of donor cell behavior and phenotype post‐transplantation. As a first step, we have shown that HuCNS‐SC protect host photoreceptors and preserve visual function after transplantation into the subretinal space of postnatal day 21 RCS rats. Moreover, cone photoreceptor density remain... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626057 Wed, 25 Jan 2012 05:00:00 +0100 5626057 http://www.medworm.com/index.php?rid=5626056&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07966.x AbstractNetwork bursts and oscillations are forms of spontaneous activity in cortical circuits that have been described in vivo and in vitro. Searching for mechanisms involved in their generation, we investigated the collective network activity and spike discharge oscillations in cortical slice cultures of neonatal rats, combining multielectrode arrays with patch clamp recordings from individual neurons. The majority of these cultures showed spontaneous collective network activity [population bursts (PBs)] that could be described as neuronal avalanches. The largest of these PBs were followed by fast spike discharge oscillations in the beta to theta range, and sometimes additional repetitive PBs, together forming seizure‐like episodes. During such episodes, all neurons showed sustained de... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626056 Wed, 25 Jan 2012 05:00:00 +0100 5626056 http://www.medworm.com/index.php?rid=5579027&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07943.x AbstractThe basolateral amygdala (BLA), ventral tegmental area and nucleus accumbens (NAc) form a functionally connected neural circuit involved in the processing of opiate‐related reward and memory. Dopamine (DA) projections from the ventral tegmental area to the BLA modulate associative plasticity mechanisms within the BLA. However, the role of DA receptor signaling in the BLA and its functional outputs to the NAc during opiate reward processing is not currently understood. Using an unbiased place conditioning procedure, we measured the rewarding effects of morphine following intra‐BLA microinfusions of specific DA D1 or D2 receptor agonists in either opiate‐naive or opiate‐dependent/withdrawn rats. Activation of intra‐BLA D1 receptors strongly potentiated the behaviorally rewa... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5579027 Thu, 12 Jan 2012 05:00:00 +0100 5579027 http://www.medworm.com/index.php?rid=5579026&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07952.x AbstractThe circadian oscillation is known to stop with prolonged inhibition of protein synthesis and to restart from a particular phase after the removal of inhibition. In order to know the underlying molecular mechanisms, the mouse suprachiasmatic nucleus was cultured and treated with a protein synthesis inhibitor, cycloheximide (CHX), for various durations. Circadian rhythms in Bmal1 expression and PER2 protein were monitored by means of bioluminescence reporters. Bmal1‐LUC and PER2::LUC bioluminescence decreased to basal levels after CHX application. CHX washout restarted the circadian rhythms from a fixed phase when CHX treatment exceeded 18 h. mRNA of Per1, Per2 and Rev‐erbα increased and reached high plateau levels in 18 h after CHX application, which continued for 48 h; ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5579026 Thu, 12 Jan 2012 05:00:00 +0100 5579026 http://www.medworm.com/index.php?rid=5626055&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07978.x AbstractThe synchronization of neuronal activity is thought to enhance information processing. There is much evidence supporting rhythmically bursting external tufted cells (ETCs) of the rodent olfactory bulb glomeruli coordinating the activation of glomerular interneurons and mitral cells via dendrodendritic excitation. However, as bursting has variable significance at axodendritic cortical synapses, it is not clear if ETC bursting imparts a specific functional advantage over the preliminary spike in dendrodendritic synaptic networks. To answer this question, we investigated the influence of single ETC bursts and spikes with the in vitro rat olfactory bulb preparation at different levels of processing, via calcium imaging of presynaptic ETC dendrites, dual electrical recording of ETC –i... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5626055 Sun, 01 Jan 2012 05:00:00 +0100 5626055 http://www.medworm.com/index.php?rid=5605592&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07941.x AbstractMasked prime tasks have shown that sensory information that has not been consciously perceived can nevertheless modulate behavior. The neuronal correlates of behavioral manifestations of visuomotor priming remain debated, particularly with respect to the distribution and direction (i.e. increase or decrease) of activity changes in medial frontal areas. Here, we predicted that these discrepant results could be accounted for by two automatic and unconscious processes embedded in this task: response conflict and facilitation. We used event‐related functional magnetic resonance imaging (fMRI), as 24 healthy participants had to respond, as fast as possible, to a target arrow presented immediately after a subliminal masked prime arrow. There were three experimental conditions defined b... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5605592 Sun, 01 Jan 2012 05:00:00 +0100 5605592 http://www.medworm.com/index.php?rid=5605591&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07956.x AbstractRegulator of calmodulin (CaM) signaling (RCS), when phosphorylated by protein kinase A (PKA) on Ser55, binds to CaM and inhibits CaM‐dependent signaling. RCS expression is high in the dorsal striatum, nucleus accumbens and amygdala, suggesting that the protein is involved in limbic‐striatal function. To test this hypothesis, we examined RCS knockout (KO) mice in behavioral models dependent on these brain areas. Mice were tested for food‐reinforced instrumental conditioning and responding under a progressive ratio (PR) schedule of reinforcement and in models of anxiety (elevated plus maze and open field). While RCS KO mice showed normal acquisition of a food‐motivated instrumental response, they exhibited a lower breakpoint value when tested on responding under a PR schedule... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5605591 Sun, 01 Jan 2012 05:00:00 +0100 5605591 http://www.medworm.com/index.php?rid=5605590&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07953.x AbstractPain communication is thought to promote automatic vicarious self‐protective responses as well as empathic concern towards others’ suffering. This duality was recently highlighted in a study showing that highly empathic individuals display increased vicarious facilitation of low‐level pain processing (nociceptive flexion reflex, NFR) combined with an unexpected reduced facilitation of self‐pain perception (pain ratings) while viewing static pictures evoking pain in others. The present study sought to test further the moderating effects of dispositional empathy on vicarious responses induced by viewing dynamic pain expressions. Twenty‐four healthy volunteers viewed 1‐s videos showing different levels of pain expression before noxious electric shocks were delivered to the... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5605590 Sun, 01 Jan 2012 05:00:00 +0100 5605590 http://www.medworm.com/index.php?rid=5605589&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07962.x We report data on the neuronal form, synaptic connectivity, neuronal excitability and epileptiform population activities generated by the hippocampus of animals with an inactivated doublecortin gene. The protein product of this gene affects neuronal migration during development. Human doublecortin (DCX) mutations are associated with lissencephaly, subcortical band heterotopia, and syndromes of intellectual disability and epilepsy. In Dcx−/Y mice, CA3 hippocampal pyramidal cells are abnormally laminated. The lamination defect was quantified by measuring the extent of the double, dispersed or single pyramidal cell layer in the CA3 region of Dcx−/Y mice. We investigated how this abnormal lamination affected two groups of synapses that normally innervate defined regions of the CA3 pyramida... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5605589 Sun, 01 Jan 2012 05:00:00 +0100 5605589 http://www.medworm.com/index.php?rid=5605588&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07955.x AbstractThe maintenance of long‐lasting forms of plasticity, such as long‐term potentiation (LTP) is dependent on the capture of plasticity‐related proteins (PRPs) in an input‐specific manner – synaptic capture. Here, it is shown that LTP, induced at Schaffer collaterals–CA1 synapses in acute rat hippocampal slice preparation, is not sensitive to protein synthesis inhibition if N‐methyl‐d‐aspartate (NMDA) receptors are blocked, suggesting that synaptic activation is involved in the modulation of LTP maintenance. Similarly, it was found that synaptic activation also determines the sensitivity of LTP to manipulations of the actin cytoskeleton dynamics. Suspending synaptic activation or concomitant NMDA receptor inhibition is sufficient to rescue the impairment on LTP mainte... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5605588 Sun, 01 Jan 2012 05:00:00 +0100 5605588 http://www.medworm.com/index.php?rid=5579025&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07963.x In this study, we showed that stargazin is highly phosphorylated at basal states and is dephosphorylated by the application of high KCl plus glutamate (K‐glu) or of a metabotropic glutamate receptor agonist, (S)‐3,5‐dihydroxyphenylglycine (DHPG), both of which chemically induced LTD in cerebellar slices. This chemically induced dephosphorylation of stargazin was specifically blocked by a calcineurin inhibitor. Indeed, inclusion of the calcineurin auto‐inhibitory peptide in the patch pipette solution completely inhibited the LTD induced by the conjunctive stimulation of PFs and Purkinje cells. Furthermore, in Purkinje cells expressing stargazin‐9D, in which all nine serine residues are mutated to aspartate, neither conjunctive stimulus nor DHPG treatment induced LTD. Finally, immu... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5579025 Sun, 01 Jan 2012 05:00:00 +0100 5579025 http://www.medworm.com/index.php?rid=5570393&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07939.x AbstractExperimental studies emphasize the importance of homeostatic plasticity as a mean of stabilizing the properties of neural circuits. In the present work we combined two techniques able to produce short‐term (5‐Hz repetitive transcranial magnetic stimulation, rTMS) and long‐term (transcranial direct current stimulation, tDCS) effects on corticospinal excitability to evaluate whether and how the effects of 5‐Hz rTMS can be tuned by tDCS preconditioning. Twelve healthy subjects participated in the study. Brief trains of 5‐Hz rTMS were applied to the primary motor cortex at an intensity of 120% of the resting motor threshold, with recording of the electromyograph traces evoked by each stimulus of the train from the contralateral abductor pollicis brevis muscle. This interventi... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5570393 Sun, 01 Jan 2012 05:00:00 +0100 5570393 http://www.medworm.com/index.php?rid=5570392&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07983.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5570392 Sun, 01 Jan 2012 05:00:00 +0100 5570392 http://www.medworm.com/index.php?rid=5570391&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07954.x AbstractIn an early stage of the postnatal development of cats, orientation maps mature and spatial frequency selectivity is consolidated. To investigate the time course of orientation map maturation associated with the consolidation of spatial frequency selectivity, we performed optical imaging of intrinsic signals in areas 17 and 18 of cats under the stimulation of drifting square‐wave gratings with different orientations and spatial frequencies. First, orientation maps for lower spatial frequencies emerged in the entire part of the lateral gyrus, which includes areas 17 and 18, and then these orientation maps in the posterior part of the lateral gyrus disappeared as orientation maps for higher spatial frequencies matured. Independent of age, an anteroposterior gradient of response str... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5570391 Sun, 01 Jan 2012 05:00:00 +0100 5570391 http://www.medworm.com/index.php?rid=5570390&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07944.x In this study we show that pupillary light responses are significantly attenuated in both Trpm1−/− and Trpm3−/− animals. Trpm1−/− mice exhibit a profound deficit in the pupillary response that is far in excess of that observed in mice lacking rods and cones (rd/rd cl) or melanopsin, and cannot be explained by defects in bipolar cell function alone. Immunolocalization studies suggest that TRPM1 is expressed in ON bipolar cells and also a subset of cells in the ganglion cell layer, including melanopsin‐expressing photosensitive retinal ganglion cells (pRGCs). We conclude that, in addition to its role in bipolar cell signalling, TRPM1 is involved in non‐image‐forming responses to light and may perform a functional role within pRGCs. By contrast, TRPM3−/− mice display a m... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5570390 Sun, 01 Jan 2012 05:00:00 +0100 5570390 http://www.medworm.com/index.php?rid=5570389&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07933.x This study underlines the large potential of SSRI‐dependent mechanisms to stimulate adult hippocampal neurogenesis in alpha‐synuclein models and may lead to novel means to improve neuropsychiatric symptoms in PD.The accumulation of alpha‐synuclein in Lewy bodies and Lewy neurites of different neuronal populations is one of the neuropathological hallmarks in Parkinson disease (PD). Overexpression of human wildtype or mutant alpha‐synuclein affects the generation of new neurons in the adult dentate gyrus (DG) of the hippocampus in models of PD. (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5570389 Sun, 01 Jan 2012 05:00:00 +0100 5570389 http://www.medworm.com/index.php?rid=5550729&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07950.x AbstractWe compared the effect of viral administration of brain‐derived neurotrophic factor (BDNF) or neurotrophin 3 (NT‐3) on locomotor recovery in adult rats with complete thoracic (T10) spinal cord transection injuries, in order to determine the effect of chronic neurotrophin expression on spinal plasticity. At the time of injury, BDNF, NT‐3 or green fluorescent protein (GFP) (control) was delivered to the lesion via adeno‐associated virus (AAV) constructs. AAV–BDNF was significantly more effective than AAV–NT‐3 in eliciting locomotion. In fact, AAV–BDNF‐treated rats displayed plantar, weight‐supported hindlimb stepping on a stationary platform, that is, without the assistance of a moving treadmill and without step training. Rats receiving AAV–NT‐3 or AAV–GFP w... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550729 Fri, 30 Dec 2011 05:00:00 +0100 5550729 http://www.medworm.com/index.php?rid=5550728&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07949.x AbstractThe current microdialysis study elucidates a functional interaction between the striatal neurotensin NTS1 receptor and the striatal dopamine D2 and N‐methyl‐d‐aspartic acid (NMDA) receptors in the regulation of striatopallidal gamma‐aminobutyric acid (GABA) and glutamate levels after an ipsilateral intranigral 6‐hydroxydopamine‐induced lesion of the ascending dopamine pathways to the striatum. Lateral globus pallidus GABA levels were higher in the lesioned group while no change was observed in striatal GABA and glutamate levels. The 6‐hydroxydopamine‐induced lesion did not alter the ability of intrastriatal NT (10 nm) to counteract the decrease in pallidal GABA and glutamate levels induced by the dopamine D2‐like receptor agonist quinpirole (10 μm). A more pr... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550728 Fri, 30 Dec 2011 05:00:00 +0100 5550728 http://www.medworm.com/index.php?rid=5550727&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07946.x AbstractGhrelin receptors are expressed by key components of the arousal system. Exogenous ghrelin induces behavioral activation, promotes wakefulness and stimulates eating. We hypothesized that ghrelin‐sensitive mechanisms play a role in the arousal system. To test this, we investigated the responsiveness of ghrelin receptor knockout (KO) mice to two natural wake‐promoting stimuli. Additionally, we assessed the integrity of their homeostatic sleep‐promoting system using sleep deprivation. There was no significant difference in the spontaneous sleep–wake activity between ghrelin receptor KO and wild‐type (WT) mice. WT mice mounted robust arousal responses to a novel environment and food deprivation. Wakefulness increased for 6 h after cage change accompanied by increases in bod... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550727 Fri, 30 Dec 2011 05:00:00 +0100 5550727 http://www.medworm.com/index.php?rid=5550731&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07951.x AbstractIn the Doppler‐shifted constant frequency processing area in the primary auditory cortex of mustached bats, Pteronotus parnellii, neurons respond to both social calls and to echolocation signals. This multifunctional nature of cortical neurons creates a paradox for simultaneous processing of two behaviorally distinct categories of sound. To test the possibility of a stimulus‐specific hemispheric bias, single‐unit responses were obtained to both types of sounds, calls and pulse‐echo tone pairs, from the right and left auditory cortex. Neurons on the left exhibited only slightly higher peak response magnitudes for their respective best calls, but they showed a significantly higher sensitivity (lower response thresholds) to calls than neurons on the right. On average, call‐t... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550731 Thu, 29 Dec 2011 05:00:00 +0100 5550731 http://www.medworm.com/index.php?rid=5550730&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07947.x AbstractElectrical synapses formed by neuronal gap junctions composed of connexin36 (Cx36) occur in most major structures in the mammalian central nervous system. These synapses link ensembles of neurons and influence their network properties. Little is known about the macromolecular constituents of neuronal gap junctions or how transmission through electrical synapses is regulated at the level of channel conductance or gap junction assembly/disassembly. Such knowledge is a prerequisite to understanding the roles of gap junctions in neuronal circuitry. Gap junctions share similarities with tight and adhesion junctions in that all three reside at close plasma membrane appositions, and therefore may associate with similar structural and regulatory proteins. Previously, we reported that the t... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550730 Thu, 29 Dec 2011 05:00:00 +0100 5550730 http://www.medworm.com/index.php?rid=5513563&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07921.x AbstractThe present study elucidated whether early life stress alters the extracellular signal‐regulated kinase (ERK) pathway that underlies fear retrieval and fear extinction based on a contextual fear conditioning paradigm, using a juvenile stress model. Levels of phospho‐ERK (pERK), the active form of ERK, increased after fear retrieval in the hippocampal CA1 region but not in the medial prefrontal cortex (mPFC). ERK activation in the CA1 following fear retrieval was not observed in adult rats who received aversive footshock (FS) stimuli during the second postnatal period (2wFS), which exhibited low levels of freezing. In fear extinction, pERK levels in the CA1 were increased by repeated extinction trials, but they were not altered after extinction retrieval. In contrast, pERK level... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5513563 Thu, 15 Dec 2011 05:00:00 +0100 5513563 http://www.medworm.com/index.php?rid=5513562&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07938.x This study aimed to relate these neurophysiological mechanisms to imagery quality. Twenty‐three healthy adults participated. First, the ability to vividly and accurately imagine performing a finger‐to‐thumb opposition task was evaluated by calculating a MI index (MII) based on psychological, behavioural and psychophysiological measurements. These scores were used to distinguish good from poor imagers. Transcranial magnetic stimulation was then used to assess modulation of corticomotor excitability, short‐interval intracortical inhibition (sICI) and short‐interval intracortical facilitation (sICF). Participants imagined abduction of their right thumb paced by a 1‐Hz metronome. Single and paired magnetic stimuli were delivered at rest, while listening to the metronome, and during... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5513562 Thu, 15 Dec 2011 05:00:00 +0100 5513562 http://www.medworm.com/index.php?rid=5502561&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07923.x AbstractOwing to methodological shortcomings and a certain conservatism that consolidates wrong assumptions in the literature, some dogmas have become established and reproduced in papers and textbooks, derived from quantitative features of the brain. The first dogma states that the cerebral cortex is the pinnacle of brain evolution – based on the observations that its volume is greater in more ‘intelligent’ species, and that cortical surface area grows more than any other brain region, to reach the largest proportion in higher primates and humans. The second dogma claims that the human brain contains 100 billion neurons, plus 10‐fold more glial cells. These round numbers have become widely adopted, although data provided by different authors have led to a broad range of 75–125... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5502561 Tue, 13 Dec 2011 05:00:00 +0100 5502561 http://www.medworm.com/index.php?rid=5502560&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07930.x AbstractMorphological and electrophysiological studies have shown that granule cell axons, the mossy fibers (MFs), establish gap junctions and therefore electrical communication among them. That granule cells express gap junctional proteins in their axons suggests the possibility that their terminals also express them. If this were to be the case, mixed electrical–chemical communication could be supported, as MF terminals normally use glutamate for fast communication with their target cells. Here we present electrophysiological studies in the rat and modeling studies consistent with this hypothesis. We show that MF activation produced fast spikelets followed by excitatory postsynaptic potentials in pyramidal cells (PCs), which, unlike the spikelets, underwent frequency potentiation and w... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5502560 Tue, 13 Dec 2011 05:00:00 +0100 5502560 http://www.medworm.com/index.php?rid=5466646&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07922.x AbstractOligodendrocytes – best known for assembling central nervous system myelin – can be categorized as precursors, myelin‐forming cells and non‐myelinating perineuronal cells. Perineuronal oligodendrocytes have been well characterized morphologically and ultrastructurally, but knowledge about their function remains scanty. It has been proposed that perineuronal oligodendrocytes support neurons and, following injury, transform into myelin‐synthesizing cells. Recent findings implicating perineuronal oligodendrocytes in cytoarchitectural abnormalities in the prefrontal cortex of schizophrenia and other psychiatric disorders shed new light on these cells. We have obtained the genetic signature of perineuronal oligodendrocytes by identifying gene expression differences between oli... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466646 Fri, 02 Dec 2011 05:00:00 +0100 5466646 http://www.medworm.com/index.php?rid=5550726&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07948.x AbstractTransmembrane AMPA receptor regulatory proteins (TARPs) are auxiliary subunits that modulate AMPA receptor trafficking, gating and pharmacology throughout the brain. Why cornichon‐2 (CNIH‐2), another AMPA receptor‐associated protein, modulates AMPA receptor gating and pharmacology in hippocampal neurons but not cerebellar granule neurons remains unresolved. Here, we report that CNIH‐2 differentially impacts Type‐Ia (γ‐2 or γ‐3) vs. Type‐Ib (γ‐4 or γ‐8) TARP‐containing AMPA receptors. Specifically, with AMPA receptors comprising γ‐2, the cerebellar‐enriched TARP isoform, CNIH‐2 decreases IKA/IGlu ratio and decreases cyclothiazide efficacy while having minimal impact on recovery from desensitization and deactivation kinetics. By contrast, with AMPA re... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5550726 Thu, 01 Dec 2011 05:00:00 +0100 5550726 http://www.medworm.com/index.php?rid=5535218&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07942.x AbstractThe development of a neuronal dendritic tree is modulated both by signals from afferent fibers and by an intrinsic program. We have previously shown that chronic activation of either type 1 metabotropic glutamate receptors (mGluR1s) or protein kinase C (PKC) in organotypic cerebellar slice cultures of mice and rats severely inhibits the growth and development of the Purkinje cell dendritic tree. The signaling events linking receptor activation to the regulation of dendritic growth remain largely unknown. We have studied whether channels allowing the entry of Ca2+ into Purkinje cells, in particular the type 3 transient receptor potential cation channels (TRPC3s), P/Q‐type Ca2+ channels, and T‐type Ca2+ channels, might be involved in signaling after mGluR1 or PKC stimulation. We ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5535218 Thu, 01 Dec 2011 05:00:00 +0100 5535218 http://www.medworm.com/index.php?rid=5521702&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07937.x AbstractPast neuroimaging studies of writing demonstrate activation foci in several regions of the posterior parietal cortex (PPC). The present study aimed to dissociate the role of the superior parietal lobule (SPL) from the other PPC regions using functional magnetic resonance imaging (fMRI) and functional connectivity. First, parametric event‐related fMRI permitted the categorical comparison of experimental writing conditions with control conditions that were carefully chosen to match the experimental conditions in terms of variables extraneous to the motor act of writing, such as visual stimulus characteristics, and generating and retrieving verbal information. A selective focus of increased activation in the PPC restricted to the rostral part of the SPL (area PE) in the left hemisph... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5521702 Thu, 01 Dec 2011 05:00:00 +0100 5521702 http://www.medworm.com/index.php?rid=5513561&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07935.x This study investigated whether contralateral noise interferes with this step of central auditory processing. Neuromagnetic 40‐Hz oscillations were examined in young healthy participants while they listened to amplitude‐modulated sound in one ear and a multi‐talker masking noise in the contralateral ear. Participants were engaged in a gap‐detection task, for which their behavioural performance declined under masking. The amplitude modulation of the stimulus elicited steady 40‐Hz oscillations with sources in bilateral auditory cortices. Analysis of the temporal dynamics of phase synchrony between source activity and the stimulus revealed two oscillatory components; the first was indicated by an instant onset in phase synchrony with the stimulus while the second showed a 200‐ms t... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5513561 Thu, 01 Dec 2011 05:00:00 +0100 5513561 http://www.medworm.com/index.php?rid=5502562&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07927.x AbstractNeuronal activity elicits metabolic and vascular responses, during which oxygen is first consumed and then supplied to the tissue via an increase in cerebral blood flow. Understanding the spatial and temporal dynamics of blood and tissue oxygen () responses following neuronal activity is crucial for understanding the physiological basis of functional neuroimaging signals. However, our knowledge is limited because previous measurements have been made at low temporal resolution (>100 ms). Here we recorded at high temporal resolution (1 ms), simultaneously with co‐localized field potentials, at several cortical depths from the whisker region of the somatosensory cortex in anaesthetized rats and mice. Stimulation of the whiskers produced rapid, laminar‐specific changes in . ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5502562 Thu, 01 Dec 2011 05:00:00 +0100 5502562 http://www.medworm.com/index.php?rid=5502559&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07936.x AbstractBrain serotonin neurons are heterogeneous and can be distinguished by several anatomical and physiological characteristics. Toward resolving this heterogeneity into classes of functional relevance, subtypes of mature serotonin neurons were previously identified based on gene expression differences initiated during development in different rhombomeric (r) segments of the hindbrain. This redefinition of mature serotonin neuron subtypes based on the criteria of genetic lineage, along with the enabling genetic fate mapping tools, now allows various functional properties, such as axonal projections, to be allocated onto these identified subtypes. Furthermore, our approach uniquely enables interconnections between the different serotonin neuron subtypes to be determined; this is especial... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5502559 Thu, 01 Dec 2011 05:00:00 +0100 5502559 http://www.medworm.com/index.php?rid=5484663&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07877.x AbstractThe functional magnetic resonance imaging (fMRI) blood oxygenation level‐dependent (BOLD) signal is regularly used to assign neuronal activity to cognitive function. Recent analyses have shown that the local field potential (LFP) gamma power is a better predictor of the fMRI BOLD signal than spiking activity. However, LFP gamma power and spiking activity are usually correlated, clouding the analysis of the neural basis of the BOLD signal. We show that changes in LFP gamma power and spiking activity in the primary visual cortex (V1) of the awake primate can be dissociated by using grating and plaid pattern stimuli, which differentially engage surround suppression and cross‐orientation inhibition/facilitation within and between cortical columns. Grating presentation yielded subst... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5484663 Thu, 01 Dec 2011 05:00:00 +0100 5484663 http://www.medworm.com/index.php?rid=5466649&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07911.x AbstractOne must be quick and precise when foveating targets to be reached, because the eyes have to guide the hand trajectory by visual feedback, and we may miss a rapidly moving target if our grasping is not fast and accurate enough. To this end, our brains developed mechanisms coordinating gaze and hand movements to optimize the way in which we foveate and reach. One of these mechanisms is the facilitation of the primary saccade – proven in humans and confirmed here in monkeys – which allows the generation of short‐latency gaze movements when reaching towards visual targets. Here we tested whether the neuronal activity in the superior colliculus (SC) accounts for this mechanism; alternatively, cortical saccade‐related areas could play a major role in the fast initiation of sacca... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466649 Thu, 01 Dec 2011 05:00:00 +0100 5466649 http://www.medworm.com/index.php?rid=5466648&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07918.x AbstractA solitary, elongated cluster of parvalbumin‐immunoreactive neurons has been previously observed in the rodent ventrolateral hypothalamus. However, the function of this so‐called PV1 nucleus is unknown. In this article, we report the results of an unbiased, broad and in‐depth molecular characterization of this small, compact group of neurons. The Allen Brain Atlas database of in situ hybridization was screened in order to identify genes expressed in the PV1‐nucleus‐containing area of the hypothalamus, and those that might be co‐expressed with parvalbumin. Although GABA is the principal neurotransmitter in parvalbumin‐expressing cells in various other brain areas, we found that PV1 neurons express the vesicular glutamate transporter (VGlut) VGlut2‐encoding gene Slc17... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466648 Thu, 01 Dec 2011 05:00:00 +0100 5466648 http://www.medworm.com/index.php?rid=5466647&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07925.x This study investigated the D‐serine modulation of non‐NMDA ionotropic glutamate receptors expressed by inner retinal neurons. We first identified that the degradation of endogenous retinal D‐serine, by application of D‐amino acid oxidase, caused an enhancement of kainate‐ and α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazoleproprionic acid (AMPA) receptor‐mediated calcium responses from the ganglion cell layer of the isolated rat retina and light‐evoked responses obtained by multi‐electrode array recordings from the guinea pig retina. Approximately 30–45% of cells were endogenously inhibited by D‐serine, as suggested by the effect of D‐amino acid oxidase. Conversely, bath application of D‐serine caused a reduction in multi‐electrode array recorded responses a... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466647 Thu, 01 Dec 2011 05:00:00 +0100 5466647 http://www.medworm.com/index.php?rid=5466645&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07928.x AbstractDisulfiram is an aldehyde dehydrogenase inhibitor used for the treatment of alcohol dependence and of cocaine addiction. It has been demonstrated that subchronic administration of disulfiram or N,N‐diethyldithiocarbamate (DEDTC), the main derivative of disulfiram, to rats can produce central–peripheral distal axonopathy. However, few data regarding the axonal effects of these compounds in the central nervous system exist. Our previous studies have revealed DEDTC‐induced axonal damage in the mouse brain during the course of postnatal development, together with alterations in axonal pathfinding and in the myelination process, with partial recovery during the post‐treatment period. In order to gather new data about how this axonal damage and recovery occurs in the central nerv... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466645 Thu, 01 Dec 2011 05:00:00 +0100 5466645 http://www.medworm.com/index.php?rid=5455202&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07931.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5455202 Wed, 30 Nov 2011 00:37:54 +0100 5455202 http://www.medworm.com/index.php?rid=5455201&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07945.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5455201 Wed, 30 Nov 2011 00:37:44 +0100 5455201 http://www.medworm.com/index.php?rid=5455198&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07919.x AbstractThe development of the posturo‐motor control of movement is conditioned by Earth’s gravity. Missing or altered gravity during the critical periods of development delays development and induces durable changes in the vestibular, cerebellar, or muscular structures, but these are not consistently mirrored at a functional level. The differences in the time schedule of vestibular and motor development could contribute to this inconstancy. To investigate the influence of gravity on the development of vestibular and locomotor functions, we analysed the performance of adult mice subjected to hypergravity during the time covering either the vestibular or locomotor development. The mice were centrifuged at 2 g from embryonic day (E) 0 to postnatal day (P) 10 (PRE), from P10 to P30 (POS... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5455198 Wed, 30 Nov 2011 00:37:15 +0100 5455198 http://www.medworm.com/index.php?rid=5466650&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07964.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5466650 Tue, 29 Nov 2011 05:00:00 +0100 5466650 http://www.medworm.com/index.php?rid=5455199&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07914.x AbstractPhasic changes in dopamine activity play a critical role in learning and goal‐directed behavior. Unpredicted reward and reward‐predictive cues evoke phasic increases in the firing rate of the majority of midbrain dopamine neurons – results that predict uniformly broadcast increases in dopamine concentration throughout the striatum. However, measurement of dopamine concentration changes during reward has cast doubt on this prediction. We systematically measured phasic changes in dopamine in four striatal subregions [nucleus accumbens shell and core (Core), dorsomedial (DMS) and dorsolateral striatum] in response to stimuli known to activate a majority of dopamine neurons. We used fast‐scan cyclic voltammetry in awake and behaving rats, which measures changes in dopamine on a... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5455199 Tue, 29 Nov 2011 05:00:00 +0100 5455199 http://www.medworm.com/index.php?rid=5455200&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07916.x AbstractRecent work has implicated dopaminergic mechanisms in overeating and obesity with some researchers suggesting parallels between the dopamine dysregulation associated with addiction and an analogous dysregulation in obesity. The precise role of dopamine in mediating reward and reinforcement, however, remains controversial. In contrast to drugs of abuse, pursuit of a natural reward, such as food, is regulated by homeostatic processes that putatively maintain a stable energy balance keeping unrestrained consumption and reward pursuit in check. Understanding how the reward system is constrained by or escapes homeostatic regulation is a critical question. The widespread use of food restriction to motivate animal subjects in behavior paradigms precludes investigation of this relationship... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5455200 Sun, 27 Nov 2011 05:00:00 +0100 5455200 http://www.medworm.com/index.php?rid=5448361&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07924.x AbstractThere is some limited evidence suggesting that the spaced application of repetitive transcranial magnetic stimulation (rTMS) protocols may extend the duration of induced neuroplastic changes. However, this has yet to be demonstrated in the human primary motor cortex (M1). We evaluated whether the paired application of an inhibitory rTMS protocol [continuous theta burst stimulation (cTBS)] at 10‐min intervals prolonged the duration of induced M1 plasticity. Motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous muscle before and following single and paired cTBS protocols applied with two intensities: 80% of active motor threshold (AMT80) and 70% of resting motor threshold (RMT70). Single cTBS protocols did not significantly influence MEP amplitudes. ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5448361 Fri, 25 Nov 2011 05:00:00 +0100 5448361 http://www.medworm.com/index.php?rid=5448360&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07926.x This study confirmed the existence of the primary field and anterior auditory field by examining the tonotopy in each field. Further, we identified a previously unreported IAF located rostral to known auditory fields. Pure tone evoked responses in the IAF exhibited the shortest latency among all auditory fields at lower frequencies. A rostroventral to dorsocaudal frequency gradient was consistently observed in the IAF in all animals examined. Neither the response amplitude nor the response duration changed with frequency in the IAF, but the area of activation exhibited a significant increase with decreasing tone frequency. Taken together, the current results indicate the existence of an IAF in mice, with characteristics suggesting a role in the rapid detection of lower frequency components... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5448360 Fri, 25 Nov 2011 05:00:00 +0100 5448360 http://www.medworm.com/index.php?rid=5448359&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07929.x AbstractStress can be a predisposing factor in the development of psychiatric disorders. However, not all individuals develop psychiatric disorders following a traumatic event. An attempt to understand these individual differences has led to a focus on factors that produce resistance. Interestingly, in rats, an experience with escapable tailshock (ES) before inescapable tailshock (IS) prevents the typical anxiety‐like behavioral outcomes of IS. This type of resistance has been termed ‘behavioral immunization’, and it depends on activation of the medial prefrontal cortex (mPFC) during ES. However, one outcome of IS that is not anxiety‐related is potentiation of morphine conditioned place preference (CPP). The present experiments investigated whether prior ES would block IS‐induced... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5448359 Fri, 25 Nov 2011 05:00:00 +0100 5448359 http://www.medworm.com/index.php?rid=5438741&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07899.x AbstractA burst of action potentials in hippocampal neurons is followed by a slow afterhyperpolarization (sAHP) that serves to limit subsequent firing. A reduction in the sAHP accompanies acquisition of several types of learning, whereas increases in the sAHP are correlated with cognitive impairment. The present study demonstrates in vitro that activity‐dependent bidirectional plasticity of the sAHP does not require synaptic activation, and depends on the pattern of action potential firing. Whole‐cell current‐clamp recordings from CA1 pyramidal neurons in hippocampal slices from young rats (postnatal days14–24) were performed in blockers of synaptic transmission. The sAHP was evoked by action potential firing at gamma‐related (50 Hz, gamma‐AHP) or theta frequencies (5 Hz, t... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438741 Sun, 20 Nov 2011 05:00:00 +0100 5438741 http://www.medworm.com/index.php?rid=5438740&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07909.x AbstractIn the present study, intracortical communication between mid/anterior insular and motor cortex was investigated during a fatiguing cycling exercise. From 16 healthy male subjects performing a constant‐load test at 60% peak oxygen consumption (VO2peak) until volitional exhaustion, electroencephalography data were analysed during repetitive, artefact‐free periods of 1‐min duration. To quantify fatigue‐induced intracortical communication, mean intra‐hemispheric lagged phase synchronization between mid/anterior insular and motor cortex was calculated: (i) at the beginning of cycling; (ii) at the end of cycling; and (iii) during recovery cycling. Results revealed significantly increased lagged phase synchronization at the end of cycling, which returned to baseline during reco... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438740 Sun, 20 Nov 2011 05:00:00 +0100 5438740 http://www.medworm.com/index.php?rid=5438739&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07915.x AbstractChronic smoking is thought to cause changes in brain reward systems that result in overvaluation of cigarette‐related stimuli and undervaluation of natural rewards. We tested the hypotheses that, in smokers, brain circuits involved in emotional processing: (i) would be more active during exposure to cigarette‐related than neutral pictures; and (ii) would be less active to pleasant compared with cigarette‐related pictures, suggesting a devaluation of intrinsically pleasant stimuli. We obtained whole‐brain blood oxygenation level‐dependent (BOLD) functional magnetic resonance imaging data from 35 smokers during the presentation of pleasant (erotica and romance), unpleasant (mutilations and sad), neutral, and cigarette‐related pictures. Whole‐brain analyses showed signif... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438739 Sun, 20 Nov 2011 05:00:00 +0100 5438739 http://www.medworm.com/index.php?rid=5419608&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07882.x We examined the morphology of recorded cells to determine if variations in dendrite structure contributed to differences in synaptic input. Although lwDR neurons had longer, more complex dendrites than vmDR neurons, glutamatergic input was not correlated with dendrite length in the lwDR, suggesting that dendrite length did not contribute to subregional differences in sEPSC frequency. Overall, glutamatergic input in the DR was the result of selective innervation of subpopulations of 5‐HT neurons and was rooted in the topography of DR neurons and the activity of glutamate neurons located within the midbrain slice. Increased glutamatergic input to lwDR cells potentially synergizes with previously reported increased intrinsic excitability of lwDR cells to increase 5‐HT output in lwDR targe... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419608 Fri, 18 Nov 2011 05:00:00 +0100 5419608 http://www.medworm.com/index.php?rid=5419607&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07886.x AbstractG protein‐gated inwardly‐rectifying K+ (GIRK/family 3 of inwardly‐rectifying K+) channels are coupled to neurotransmitter action and can play important roles in modulating neuronal excitability. We investigated the temporal and spatial expression of GIRK1, GIRK2 and GIRK3 subunits in the developing and adult brain of mice and rats using biochemical, immunohistochemical and immunoelectron microscopic techniques. At all ages analysed, the overall distribution patterns of GIRK1‐3 were very similar, with high expression levels in the neocortex, cerebellum, hippocampus and thalamus. Focusing on the hippocampus, histoblotting and immunohistochemistry showed that GIRK1‐3 protein levels increased with age, and this was accompanied by a shift in the subcellular localization of the... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419607 Fri, 18 Nov 2011 05:00:00 +0100 5419607 http://www.medworm.com/index.php?rid=5419606&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07887.x In this study, we evaluated the hypothesis that spike timing is also used to distinguish between speech sounds in noisy conditions that significantly degrade neural responses to speech sounds. We tested speech sound discrimination in rats and recorded primary auditory cortex (A1) responses to speech sounds in background noise of different intensities and spectral compositions. Our behavioral results indicate that rats, like humans, are able to accurately discriminate consonant sounds even in the presence of background noise that is as loud as the speech signal. Our neural recordings confirm that speech sounds evoke degraded but detectable responses in noise. Finally, we developed a novel neural classifier that mimics behavioral discrimination. The classifier discriminates between speech so... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419606 Fri, 18 Nov 2011 05:00:00 +0100 5419606 http://www.medworm.com/index.php?rid=5419605&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07889.x AbstractSensorimotor integration is important for motor learning. The inferior parietal lobe, through its connections with the frontal lobe and cerebellum, has been associated with multisensory integration and sensorimotor adaptation for motor behaviors other than speech. In the present study, the contribution of the inferior parietal cortex to speech motor learning was evaluated using repetitive transcranial magnetic stimulation (rTMS) prior to a speech motor adaptation task. Subjects’ auditory feedback was altered in a manner consistent with the auditory consequences of an unintended change in tongue position during speech production, and adaptation performance was used to evaluate sensorimotor plasticity and short‐term learning. Prior to the feedback alteration, rTMS or sham stimula... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419605 Fri, 18 Nov 2011 05:00:00 +0100 5419605 http://www.medworm.com/index.php?rid=5419604&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07891.x AbstractCaspase 3 activation has been linked to the acute neurotoxic effects of central nervous system damage, as in traumatic brain injury or cerebral ischaemia, and also to the early events leading to long‐term neurodegeneration, as in Alzheimer’s disease. However, the precise mechanisms activating caspase 3 in neuronal injury are unclear. RhoB is a member of the Rho GTPase family that is dramatically induced by cerebral ischaemia or neurotrauma, both in preclinical models and clinically. In the current study, we tested the hypothesis that RhoB might directly modulate caspase 3 activity and apoptotic or necrotic responses in neurons. Over‐expression of RhoB in the NG108‐15 neuronal cell line or in cultured corticohippocampal neurons elevated caspase 3 activity without inducing ov... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419604 Fri, 18 Nov 2011 05:00:00 +0100 5419604 http://www.medworm.com/index.php?rid=5419602&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07890.x AbstractThe transcription factor Nkx2‐1 belongs to the homeobox‐encoding family of proteins that have essential functions in prenatal brain development. Nkx2‐1 is required for the specification of cortical interneurons and several neuronal subtypes of the ventral forebrain. Moreover, this transcription factor is involved in migratory processes by regulating the expression of guidance molecules. Interestingly, Nkx2‐1 expression was recently detected in the mouse brain at postnatal stages. Using two transgenic mouse lines that allow prenatal or postnatal cell type‐specific deletion of Nkx2‐1, we show that continuous expression of the transcription factor is essential for the maturation and maintenance of cholinergic basal forebrain neurons in mice. Notably, prenatal deletion of N... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419602 Fri, 18 Nov 2011 05:00:00 +0100 5419602 http://www.medworm.com/index.php?rid=5419601&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07898.x AbstractNursing in the rabbit is under circadian control, and pups have a daily anticipatory behavioral arousal synchronized to this unique event, but it is not known which signal is the main entraining cue. In the present study, we hypothesized that food is the main entraining signal. Using mother‐deprived pups, we tested the effects of artificial feeding on the synchronization of locomotor behavior, plasma glucose, corticosterone, c‐Fos (FOS) and PERIOD1 (PER1) rhythms in suprachiasmatic, supraoptic, paraventricular and tuberomammillary nuclei. At postnatal day 1, an intragastric tube was placed by gastrostomy. The next day and for the rest of the experiment, pups were fed with a milk formula through the cannula at either 02:00 h or 10:00 h [feeding time = zeitgeber time (ZT)... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419601 Fri, 18 Nov 2011 05:00:00 +0100 5419601 http://www.medworm.com/index.php?rid=5419600&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07900.x AbstractExpression of connexin26 (Cx26), Cx30 and Cx43 in astrocytes and expression of Cx29, Cx32 and Cx47 in oligodendrocytes of adult rodent brain has been well documented, as has the interdependence of connexin expression patterns of macroglial cells in Cx32‐ and Cx47‐knockout mice. To investigate this interdependence further, we examined immunofluorescence labelling of glial connexins in transgenic Cx30 null mice. Ablation of astrocytic Cx30, confirmed by the absence of immunolabelling for this connexin in all brain regions, resulted in the loss of its coupling partner Cx32 on the oligodendrocyte side of astrocyte–oligodendrocyte (A/O) gap junctions, but had no effect on the localization of astrocytic Cx43 and oligodendrocytic Cx47 at these junctions or on the distribution of Cx3... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419600 Fri, 18 Nov 2011 05:00:00 +0100 5419600 http://www.medworm.com/index.php?rid=5419599&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07901.x AbstractIn the postnatal neurogenic niche, two populations of astrocyte‐like cells (B cells) persist, one acting as neural progenitor cells (NPCs, B1 cells) and one forming a structural boundary between the neurogenic niche and the striatum (B2 cells, niche astrocytes). Despite being viewed as two distinct entities, we found that B1 and B2 cells express the gap junction protein connexin 43 and display functional coupling involving 50–60 cells. Using neonatal electroporation to label slowly cycling radial glia‐derived B1 cells, which send a basal process onto blood vessels, we further confirmed dye coupling between NPCs. To assess the functionality of the coupling, we used calcium imaging in a preparation preserving the three‐dimensional architecture of the subventricular zone. Inte... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419599 Fri, 18 Nov 2011 05:00:00 +0100 5419599 http://www.medworm.com/index.php?rid=5419598&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07903.x AbstractWhen we encode faces in memory, we often do so in association with biographical information regarding the person. To examine the neural dynamics underlying such encoding processes, we devised a face recognition task and recorded cortical activity using magnetoencephalography. The task included two conditions. In the experimental condition, face stimuli were preceded by biographical information regarding the person whose face was to be memorized, whereas in the control condition, nonsense syllables were presented before face stimuli. Behavioral results indicated that the biographical information about a person facilitated the recognition memory of their face. Magnetoencephalography signals showed clear visually evoked magnetic fields mainly in the occipitotemporal cortex, in respons... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419598 Fri, 18 Nov 2011 05:00:00 +0100 5419598 http://www.medworm.com/index.php?rid=5419613&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07888.x AbstractUsing a transgenic mouse (Mus musculus) in which nestin‐expressing progenitors are labeled with enhanced green fluorescent protein, we previously characterized the expression of excitatory amino acid transporter 2 (GltI) and excitatory amino acid transporter 1 (Glast) on early neural progenitors in vivo. To address their functional role in this cell population, we manipulated their expression in P7 neurospheres isolated from the dentate gyrus. We observed that knockdown of GltI or Glast was associated with decreased bromodeoxyuridine incorporation and neurosphere formation. Moreover, we determined that both glutamate transporters regulated progenitor proliferation in a calcium‐dependent and metabotropic glutamate receptor‐dependent manner. To address the relevance of this in ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419613 Thu, 17 Nov 2011 05:00:00 +0100 5419613 http://www.medworm.com/index.php?rid=5419612&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07905.x In this study, we focus on the functional effects of aging on auditory cortex responses. Neuronal discharges and local field potentials were recorded in the auditory cortex of aged guinea pigs (> 3 years), and several parameters characterizing the processing of auditory information were quantified: the acoustic thresholds, response strength, latency and duration of the response, and breadth of tuning. Several of these parameters were also quantified from auditory brainstem responses collected from the same animals, and recordings obtained from a population of animals with trauma‐induced hearing loss were also included in this study. The results showed that aging and acoustic trauma reduced the response strength at both brainstem and cortical levels, and increased the response late... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419612 Thu, 17 Nov 2011 05:00:00 +0100 5419612 http://www.medworm.com/index.php?rid=5419611&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07906.x AbstractThe septohippocampal (SH) pathway comprises cholinergic and GABAergic fibers. Whereas the former establish synaptic contacts with all types of hippocampal neurons, the latter form complex baskets specifically on interneurons. The GABAergic SH function is associated with the control of hippocampal synchronous networks. Little is known about the mechanisms involved in the formation of the GABAergic SH pathway. Semaphorin (Sema) 3C is expressed in most hippocampal interneurons targeted by these axons. To ascertain whether Sema 3C influences the formation of the SH pathway, we analyzed the development of this connection in Sema 3C‐deficient mice. As these animals die at birth, we developed an in vitro organotypic co‐culture model reproducing the postnatal development of the SH path... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419611 Thu, 17 Nov 2011 05:00:00 +0100 5419611 http://www.medworm.com/index.php?rid=5419609&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07908.x AbstractMatrix metalloproteinases (MMPs) are implicated in diverse processes, such as neuroinflammation, leakiness of the blood–brain barrier (BBB) and direct cellular damage in neurodegenerative and other CNS diseases. Tissue destruction by MMPs is regulated by their endogenous tissue inhibitors (TIMPs). TIMPs prevent excessive MMP‐related degradation of extracellular matrix components. In a rat model of human immunodeficiency virus (HIV)‐related encephalopathy, we described MMP‐2 and MMP‐9 upregulation by HIV‐1 envelope gp120, probably via gp120‐induced reactive oxygen species. Antioxidant gene delivery blunted gp120‐induced MMP production. We also studied the effect of gp120 on TIMP‐1 and TIMP‐2 production. TIMP‐1 and TIMP‐2 levels increased 6 h after gp120 inj... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419609 Thu, 17 Nov 2011 05:00:00 +0100 5419609 http://www.medworm.com/index.php?rid=5405160&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07877.x AbstractThe functional magnetic resonance imaging (fMRI) blood oxygenation level‐dependent (BOLD) signal is regularly used to assign neuronal activity to cognitive function. Recent analyses have shown that the local field potential (LFP) gamma power is a better predictor of the fMRI BOLD signal than spiking activity. However, LFP gamma power and spiking activity are usually correlated, clouding the analysis of the neural basis of the BOLD signal. We show that changes in LFP gamma power and spiking activity in the primary visual cortex (V1) of the awake primate can be dissociated by using grating and plaid pattern stimuli, which differentially engage surround suppression and cross‐orientation inhibition/facilitation within and between cortical columns. Grating presentation yielded subst... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5405160 Mon, 14 Nov 2011 05:00:00 +0100 5405160 http://www.medworm.com/index.php?rid=5405159&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07895.x In conclusion, greater spinal cord atrophy predicts changes at the cortical level that lead to reduced excitability and increased inhibition. Therefore, cortical forearm motor representations may reorganize towards the intrinsic hand motor representation to maximize output to muscles of the impaired forearm following SCI.Functional imaging studies, using blood oxygen level‐dependent signals, have demonstrated cortical reorganization of forearm muscle maps towards the denervated leg area following spinal cord injury (SCI). The extent of cortical reorganization was predicted by spinal atrophy. (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5405159 Mon, 14 Nov 2011 05:00:00 +0100 5405159 http://www.medworm.com/index.php?rid=5448358&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07940.x AbstractBiologically relevant odours were used to stimulate olfactory tubercle neurons in anaesthetized male rats. Among 120 recorded neurons, 118 showed spontaneous activity (mean firing rate, 15.0 ± 1.4 spikes/s). Ninety‐eight neurons were exposed to at least one of the four following odour sources: an empty vial, or a vial containing food pellets (familiar odour), a sample of oestrous rat faeces (conspecific sexual odour), or a sample of male fox faeces (predator odour). The proportion of neurons responding with a change in activity was significantly linked to the odour applied. Repetition of the stimulation with the same odour elicited the same activity change. Between 50 and 70% of neuronal activity changes were not accompanied by respiration changes. Fifty‐six neurons were e... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5448358 Tue, 01 Nov 2011 04:00:00 +0100 5448358 http://www.medworm.com/index.php?rid=5438759&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07894.x AbstractInnervation of Purkinje cells (PCs) by multiple climbing fibers (CFs) is refined into mono‐innervation during the first three postnatal weeks of rodents’ lives. In this review article, we will integrate the current knowledge on developmental process and mechanisms of CF synapse elimination. In the ‘creeper’ stage of CF innervation (postnatal day 0 (P0)∼), CFs creep among PC somata to form transient synapses on immature dendrites. In the ‘pericellular nest’ stage (P5∼), CFs densely surround and innervate PC somata. CF innervation is then displaced to the apical portion of PC somata in the ‘capuchon’ stage (P9∼), and translocate to dendrites in the ‘dendritic’ (P12∼) stage. Along with the developmental changes in CF wiring, functional and morphological dis... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438759 Tue, 01 Nov 2011 04:00:00 +0100 5438759 http://www.medworm.com/index.php?rid=5438758&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07872.x AbstractMost GABAergic interneurons in the cortex are born at embryonic stages in the ganglionic eminences and migrate tangentially to their final destination. They continue, however, to differentiate and functionally integrate in the circuitry until later postnatal stages of the rodent brain. Recent investigations show that interneurons undergo marked changes in their morphological, intrinsic and synaptic properties as they mature. Action potential shape and its propagation, the period of transmitter release and the time course of the postsynaptic GABAA receptor‐mediated conductance become faster during the first three to four postnatal weeks, resulting in a developmental switch of interneurons from slow to fast signalling units. At the same time, the nature of GABAergic signalling is c... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438758 Tue, 01 Nov 2011 04:00:00 +0100 5438758 http://www.medworm.com/index.php?rid=5438757&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07878.x AbstractAt the earliest developmental stages, sensory neocortical areas in various species reveal distinct patterns of spontaneous neuronal network activity. These activity patterns either propagate over large neocortical areas or synchronize local neuronal ensembles. In vitro and in vivo experiments indicate that these spontaneous activity patterns are generated from neuronal networks in the cerebral cortex, in subcortical structures or in the sensory periphery (retina, cochlea, whiskers). At early stages spontaneous periphery‐driven and also sensory evoked activity is relayed to the developing cerebral cortex via the thalamus and the neocortical subplate, which amplifies the afferent sensory input. These early local and large‐scale neuronal activity patterns influence a variety of de... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438757 Tue, 01 Nov 2011 04:00:00 +0100 5438757 http://www.medworm.com/index.php?rid=5438756&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07892.x AbstractSensory inputs triggered by external stimuli are projected into discrete arrays of neuronal modules in the primary sensory cortex. This whisker‐to‐barrel pathway has gained in popularity as a model system for studying the development of cortical circuits and sensory processing because its clear patterns facilitate the identification of genetically modified mice with whisker map deficits and make possible coordinated in vitro and in vivo electrophysiological studies. Numerous whisker map determinants have been identified in the past two decades. In this review, we summarize what have we learned from the detailed studies conducted in various mutant mice with cortical whisker map deficits. We will specifically focus on the anatomical and functional establishment of the somatosenso... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438756 Tue, 01 Nov 2011 04:00:00 +0100 5438756 http://www.medworm.com/index.php?rid=5438755&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07897.x AbstractActin‐capping and anti‐capping proteins are crucial regulators of actin dynamics. Recent studies have indicated that these proteins may be heavily involved in all stages of synaptogenesis, from the emergence of filopodia, through neuritogenesis and synaptic contact stabilization, to the structural changes occurring at the synapse during potentiation phenomena. In this review, we focus on recent evidence pointing to an active role of actin‐capping and anti‐capping proteins in orchestrating the processes controlling neuronal connectivity and plasticity.Actin‐capping and anti‐capping proteins are crucial regulators of actin dynamics. Recent studies have indicated that these proteins may be heavily involved in all stages of synaptogenesis, from the emergence of filopodia, t... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438755 Tue, 01 Nov 2011 04:00:00 +0100 5438755 http://www.medworm.com/index.php?rid=5438754&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07817.x AbstractDuring the development of the nervous system, neurons often connect axons and dendrites over long distances, which are navigated by chemical cues. During the past few decades, studies on axon guidance have focused on chemical cues provided by the axonal target or intermediate target. However, recent studies have shed light on the roles and mechanisms underlying axon–axon interactions during neuronal circuit assembly. The roles of axon–axon interactions are best exemplified in recent studies on olfactory map formation in vertebrates. Pioneer–follower interaction is essential for the axonal pathfinding process. Pre‐target axon sorting establishes the anterior–posterior map order. The temporal order of axonal projection is converted to dorsal–ventral topography with the ai... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438754 Tue, 01 Nov 2011 04:00:00 +0100 5438754 http://www.medworm.com/index.php?rid=5438753&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07831.x AbstractUntil recently, endocannabinoid (eCB) signalling was largely studied in the context of synaptic plasticity in the postnatal brain in the absence of detailed knowledge of the nature of the enzyme(s) responsible for the synthesis of the eCBs. However, the identification of two diacylglycerol lipases (DAGLα and DAGLβ) responsible for the synthesis of 2‐arachidonoylglycerol (2‐AG) has increased the understanding of where this eCB is synthesised in relationship to the expression of cannabinoid receptor (CB)1 and CB2. Furthermore, the generation of knockout animals for each enzyme has allowed for the direct testing of their importance for established and emerging eCB functions. Based on this, we now know that DAGLα is enriched in dendritic spines that appose CB1‐positive synapti... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438753 Tue, 01 Nov 2011 04:00:00 +0100 5438753 http://www.medworm.com/index.php?rid=5438752&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07845.x AbstractEphB receptor tyrosine kinases direct axonal pathfinding through interactions with ephrin‐B proteins following axon–cell contact. As EphB:ephrin‐B binding leads to bidirectional signals, the contributions of signaling into the Eph‐expressing cell (forward signaling) or the ephrin‐expressing cell (reverse signaling) cannot be assigned using traditional protein null alleles. To determine if EphB1 is functioning solely as a receptor during axon pathfinding, a new knock‐in mutant mouse was created, EphB1T‐lacZ, which expresses an intracellular‐truncated EphB1‐β‐gal fusion protein from the endogenous locus. As in the EphB1−/− protein null animals, the EphB1T‐lacZ/T‐lacZ homozygotes fail to form the ipsilateral projecting subpopulation of retinal ganglion cel... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438752 Tue, 01 Nov 2011 04:00:00 +0100 5438752 http://www.medworm.com/index.php?rid=5438751&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07875.x AbstractThe axon initial segment (AIS), with its dense clusters of voltage‐gated ion channels decorating the axonal membrane, regulates action potential initiation and modulation. The AIS also functions as a barrier to maintain axodendritic polarity, and its precise axonal location contributes to the fine‐tuning of neuronal excitability. Therefore, it is not surprising that mutations in AIS‐related genes, disruption of the molecular organization of the AIS and altered AIS ion channel expression, function, location and/or density are emerging as key players in neurological disorders. Here, we consider the role of the AIS in nervous system disease and injury.The axon initial segment (AIS), with its dense clusters of voltage‐gated ion channels decorating the axonal membrane, regulates... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438751 Tue, 01 Nov 2011 04:00:00 +0100 5438751 http://www.medworm.com/index.php?rid=5438750&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07867.x AbstractThe cerebral cortex is a complex six‐layered structure that contains an important diversity of neurons, and has rich local and extrinsic connectivity. Among the mechanisms governing the cerebral cortex construction, neuronal migration is perhaps the most crucial as it ensures the timely formation of specific and selective neuronal circuits. Here, we review the main extrinsic and extrinsic factors involved in regulating neuronal migration in the cortex and describe some environmental factors interfering with their actions.The cerebral cortex is a complex six‐layered structure that contains an important diversity of neurons, and has rich local and extrinsic connectivity. Among the mechanisms governing the cerebral cortex construction, neuronal migration is perhaps the most crucia... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438750 Tue, 01 Nov 2011 04:00:00 +0100 5438750 http://www.medworm.com/index.php?rid=5438749&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07896.x AbstractCortical interneurons originate in the ganglionic eminences of the subpallium and migrate into the cortex in well‐defined tangential streams. At the start of corticogenesis, two streams of migrating neurons are evident: a superficial one at the level of the preplate (PPL), and a deeper one at the level of the intermediate zone (IZ). Currently, little is known about the signalling mechanisms that regulate interneuron migration, and almost nothing is known about the molecules that may be involved in their choice of migratory stream. Here, we performed a microarray analysis, comparing the changes in gene expression between cells migrating in the PPL and those migrating in the IZ at embryonic day 13.5. This analysis identified genes, many of them novel, that were upregulated in one o... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438749 Tue, 01 Nov 2011 04:00:00 +0100 5438749 http://www.medworm.com/index.php?rid=5438748&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07884.x This article reviews the literature relevant to long‐term gene expression disturbances in the human fetal brain in relation to maternal cannabis and cigarette use. To provide translational insights, we discuss animal models in which protracted molecular consequences of prenatal cannabis and cigarette exposure can be better explored and which enable future evaluation of epigenetic pathways, such as DNA methylation and histone modification, that could potentially maintain abnormal gene regulation and related behavioral disturbances. Altogether, this information may help to address the current gaps of knowledge regarding the impact of early drug exposure that set in motion lifelong molecular disturbances that underlie vulnerability to psychiatric disorders.Prenatal development is highly sen... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438748 Tue, 01 Nov 2011 04:00:00 +0100 5438748 http://www.medworm.com/index.php?rid=5438747&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07860.x AbstractAutonomic neuron development is controlled by a network of transcription factors, which is induced by bone morphogenetic protein signalling in neural crest progenitor cells. This network intersects with a transcriptional program in migratory neural crest cells that pre‐specifies autonomic neuron precursor cells. Recent findings demonstrate that the transcription factors acting in the initial specification and differentiation of sympathetic neurons are also important for the proliferation of progenitors and immature neurons during neurogenesis. Elimination of Phox2b, Hand2 and Gata3 in differentiated neurons affects the expression of subtype‐specific and/or generic neuronal properties or neuron survival. Taken together, transcription factors previously shown to act in initial ne... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438747 Tue, 01 Nov 2011 04:00:00 +0100 5438747 http://www.medworm.com/index.php?rid=5438746&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07910.x AbstractThe main features of the development of the serotonin (5‐HT) raphe neurons have been known for many years but more recent molecular studies, using mouse genetics, have since unveiled several intriguing aspects of the specification of the raphe serotonergic system. These studies indicated that, although all 5‐HT neurons in the raphe follow the same general program for their specification, there are also clear regional differences in the way that these neurons are specified and are guided towards different brain targets. Here we overview recent progress made in the understanding of the developmental programming of serotonergic neurons in the mouse raphe, emphasizing data showing how heterogeneous subsets of 5‐HT neurons may be generated. Serotonergic progenitors are produced in... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438746 Tue, 01 Nov 2011 04:00:00 +0100 5438746 http://www.medworm.com/index.php?rid=5438745&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07904.x AbstractThe locally projecting GABAergic interneurons of the mammalian cerebral cortex are a highly heterogeneous population, whose malfunction or deficit has been implicated in a wide range of neurological disorders. However, the low incidence of the various distinct interneuron populations within the neocortex, combined with the lack of molecular or physiological markers specific to these subtypes, have hampered investigations into their function in the normal and dysfunctional brain. A number of research groups have begun to elucidate the developmental genetic mechanism that underpins this diversity in the mouse neocortex, spurred on by the knowledge that the temporal and spatial origin of an interneuron in the embryonic brain is predictive of its eventual intrinsic properties in the ma... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438745 Tue, 01 Nov 2011 04:00:00 +0100 5438745 http://www.medworm.com/index.php?rid=5438744&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07883.x AbstractTouch sensation is mediated by specific subtypes of sensory neurons which develop in a hierarchical process from common early progenitor neurons, but the molecular mechanism that underlies diversification of touch‐sensitive mechanoreceptive neurons is not fully known. Here, we use genetically manipulated mice to examine whether the transcription factor short stature homeobox 2 (Shox2) participates in the acquisition of neuronal subtypes conveying touch sensation. We show that Shox2 encodes the development of category I low‐threshold mechanoreceptive neurons in glabrous skin, i.e. discriminative touch‐sensitive neurons which form innervations of epidermal Merkel cell and Meissner corpuscles. In contrast, other sensory fiber endings, including those innervating Pacinian corpusc... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438744 Tue, 01 Nov 2011 04:00:00 +0100 5438744 http://www.medworm.com/index.php?rid=5438743&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07871.x AbstractDuring early vertebrate development, the embryonic ectoderm becomes subdivided into neural, neural plate border (border) and epidermal regions. The nervous system is derived from the neural and border domains which, respectively, give rise to the central and peripheral nervous systems. To better understand the functional nervous system we need to know how individual neurons are specified and connected. Our understanding of the early development of the peripheral nervous system has been lagging compared to knowledge regarding central nervous system and epidermal cell lineage decision. Recent advances have shown when and how the specification of border cells is initiated. One important insight is that border specification is already initiated at blastula stages, and can be molecularl... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438743 Tue, 01 Nov 2011 04:00:00 +0100 5438743 http://www.medworm.com/index.php?rid=5438742&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07912.x What are the precise molecular and cellular mechanisms that the human brain exploits to encode consciousness, identity and thought? This undoubtedly remains one of the greatest scientific challenges facing mankind. (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438742 Tue, 01 Nov 2011 04:00:00 +0100 5438742 http://www.medworm.com/index.php?rid=5438738&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07932.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5438738 Tue, 01 Nov 2011 04:00:00 +0100 5438738 http://www.medworm.com/index.php?rid=5419597&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07907.x AbstractA‐type K+ current (IA) plays a critical role in controlling the excitability of pyramidal cell (PC) dendrites. In vitro dendritic patch‐pipette recordings have demonstrated a prominent, sixfold increase in IA density along the main apical dendrites of rat hippocampal CA1 PCs. In these cells, IA is mediated by Kv4.2 subunits, whose precise subcellular distribution and densities in small‐diameter oblique dendrites and dendritic spines are still unknown. Here we examined the densities of the Kv4.2 subunit in 13 axo‐somato‐dendritic compartments of CA1 PCs using a highly sensitive, high‐resolution quantitative immunogold localization method (sodium dodecyl sulphate‐digested freeze‐fracture replica‐labelling). Only an approximately 70% increase in Kv4.2 immunogold dens... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5419597 Tue, 01 Nov 2011 04:00:00 +0100 5419597 http://www.medworm.com/index.php?rid=5405158&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07902.x AbstractThe overwhelming majority of research in the neurosciences employs P‐values stemming from tests of statistical significance to decide on the presence or absence of an effect of some treatment variable. Although a continuous variable, the P‐value is commonly used to reach a dichotomous decision about the presence of an effect around an arbitrary criterion of 0.05. This analysis strategy is widely used, but has been heavily criticized in the past decades. To counter frequent misinterpretations of P‐values, it has been advocated to complement or replace P‐values with measures of effect size (MES). Many psychological, biological and medical journals now recommend reporting appropriate MES. One hindrance to the more frequent use of MES may be their scarcity in standard statistic... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5405158 Tue, 01 Nov 2011 04:00:00 +0100 5405158 http://www.medworm.com/index.php?rid=5378144&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07881.x AbstractBax is a pro‐death protein that plays a crucial role in developmental neuronal cell death. Bax−/− mice exhibit increased neuron number and lack several neural sex differences. Here we examined the effects of Bax gene deletion on social behaviors (olfactory preference, social recognition, social approach and aggression) and the neural processing of olfactory cues. Bax deletion eliminated the normal sex difference in olfactory preference behavior. In the social recognition test, both genotypes discriminated a novel conspecific, but wild‐type males and Bax−/− animals of both sexes spent much more time than wild‐type females investigating stimulus animals. Similarly, Bax−/− mice were more sociable than wild‐type mice in a social approach test. Bax deletion had no ef... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378144 Tue, 01 Nov 2011 04:00:00 +0100 5378144 http://www.medworm.com/index.php?rid=5378143&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07880.x AbstractRats exposed to timed restricted meals develop anticipation of food. They increase their activity levels in the hours preceding food access; this has been described as food‐anticipatory activity (FAA). In the present study, we show the involvement of regions of the hypothalamus [arcuate nucleus, dorsomedial hypothalamus (DMH) and lateral hypothalamus] in the early development of FAA in rats exposed to the activity‐based anorexia (ABA) model. We thereby used two different paradigms, rats exposed to the ABA model (ABA‐normal) and rats exposed to the same restraint in food access but on a random feeding schedule (ABA‐random). The latter group of rats were not able to anticipate food. We found a strong correlation between the expression of food anticipation measured by running�... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378143 Tue, 01 Nov 2011 04:00:00 +0100 5378143 http://www.medworm.com/index.php?rid=5378142&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07865.x AbstractParkinson’s disease is characterized by degeneration of nigral dopaminergic neurons, leading to a wide variety of psychomotor dysfunctions. Accumulated evidence suggests that abnormally synchronized oscillations in the basal ganglia contribute to the expression of parkinsonian motor symptoms. However, the mechanism that generates abnormal oscillations in a dopamine‐depleted state remains poorly understood. We addressed this question by examining basal ganglia neuronal activity in two 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine‐treated parkinsonian monkeys. We found that systemic administration of l‐3,4‐dihydroxyphenylalanine (l‐DOPA; dopamine precursor) decreased abnormal neuronal oscillations (8–15 Hz) in the internal segment of the globus pallidus (GPi)... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378142 Tue, 01 Nov 2011 04:00:00 +0100 5378142 http://www.medworm.com/index.php?rid=5378141&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07869.x We examined if ageing alters the efficacy of afferent modulation of SICI. Previously, electrical cutaneous stimulation of a finger has been shown to reduce SICI in the motor cortices of young adults. Paired‐pulse transcranial magnetic stimulation was used to assess SICI in the cortical representation of the first dorsal interosseous muscle. SICI was assessed separately under two conditions: with and without prior afferent input from electrical cutaneous stimulation of the index finger. Fifteen ‘young’ (20.1 ± 2.1 years) and 15 ‘old’ male humans (65.5 ± 3.9 years) were studied. SICI did not differ when young and old males were compared. However, when preceded by electrical cutaneous finger stimulation, SICI was reduced in young men but not old men. Reflex testing ind... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378141 Tue, 01 Nov 2011 04:00:00 +0100 5378141 http://www.medworm.com/index.php?rid=5378139&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07866.x AbstractFollowing brain damage, especially in juvenile animals, large‐scale reorganization is known to occur in the remaining brain structures to compensate for functional deficits. In rats with neonatal hemidecortication, corticospinal fibers originating from the undamaged side of the sensorimotor cortex issue collateral sprouts to the ipsilateral spinal gray matter that mediate cortical excitation to ipsilateral forelimb motoneurons and compensate for the deficit in forelimb movements. The present study was designed to investigate the origins of the ipsilateral corticospinal projection in neonatally hemidecorticated rats. Corticospinal neurons (CSNs) were labeled in adults by injecting retrograde neural tracers, cholera toxin subunit B with different fluorescent probes, into either sid... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378139 Tue, 01 Nov 2011 04:00:00 +0100 5378139 http://www.medworm.com/index.php?rid=5378138&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07868.x AbstractOrexins influence various physiological processes associated with feeding behaviour, endocrine functions and wakefulness. One component of mammalian circadian timing systems, intergeniculate leaflet (IGL) of the lateral geniculate nucleus, is thought to contribute to circadian entrainment by processing photic and non‐photic/arousal‐related signals. Because the IGL is possibly innervated by the orexinergic system, using in vitro extracellular recording techniques we evaluated the influence of orexin A (OXA) and orexin B (OXB) on the rate and pattern of neuronal firing in this structure. Significant increases in the activity of 33 and 28% of IGL cells were observed after locally applied OXA (1 μm) and OXB (1 μm), respectively. In the great majority of neurons responses to O... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378138 Tue, 01 Nov 2011 04:00:00 +0100 5378138 http://www.medworm.com/index.php?rid=5378137&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07879.x We describe here a simple complementary method that recovers many findings of these more complex methods but relies only on a basic patch‐clamp recording approach. Somatic short and long current pulses were applied in vitro to striatal medium spiny (MS) and fast spiking (FS) neurons from juvenile rats. The passive dynamics were quantified by fitting two‐compartment models to the short current pulse data. Lumped conductances for the active dynamics were then found by compensating this fitted passive dynamics within the current–voltage relationship from the long current pulse data. These estimated passive and active properties were consistent with previous more complex estimations of the neuron properties, supporting the approach. Relationships within the MS and FS neuron types were al... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378137 Tue, 01 Nov 2011 04:00:00 +0100 5378137 http://www.medworm.com/index.php?rid=5378135&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07874.x AbstractIt is well established that the cannabinoid and dopamine systems interact at various levels to regulate basal ganglia function. Although it is well known that acute administration of cannabinoids to mice can modify dopamine‐dependent behaviors, the intraneuronal signaling pathways employed by these agents in the striatum are not well understood. Here we used knockout mouse models to examine the regulation of striatal extracellular‐signal‐regulated kinases 1 and 2 (ERK1/2) signaling by behaviorally relevant doses of cannabinoids. This cellular pathway has been implicated as a central mediator of drug reward and synaptic plasticity. In C57BL/6J mice, acute administration of the cannabinoid agonists, (−)‐11‐hydroxydimethylheptyl‐Δ8‐tetrahydrocannabinol (HU‐210) and ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378135 Tue, 01 Nov 2011 04:00:00 +0100 5378135 http://www.medworm.com/index.php?rid=5378134&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07876.x AbstractAbnormal dopamine (DA) transmission in the striatum plays a pivotal role in attention‐deficit/hyperactivity disorder (ADHD). As striatal DA signalling modulates the endocannabinoid system (ECS), the present study was aimed at investigating cannabinoid CB1 receptor (CB1R) function in a model of ADHD obtained by triple point‐mutation in the dopamine transporter (DAT) gene in mice, making them insensitive to cocaine [DAT cocaine‐insensitive (DAT‐CI) mice]. DAT‐CI mice had a marked hyperactive phenotype, and neurophysiological recordings revealed that the sensitivity of CB1Rs controlling GABA‐mediated synaptic currents [CB1Rs(GABA)] in the striatum was completely lost. In contrast, CB1Rs modulating glutamate transmission [CB1Rs(Glu)], and GABAB receptors were not affected i... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378134 Tue, 01 Nov 2011 04:00:00 +0100 5378134 http://www.medworm.com/index.php?rid=5378133&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07917.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378133 Tue, 01 Nov 2011 04:00:00 +0100 5378133 http://www.medworm.com/index.php?rid=5378131&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07893.x AbstractThe current study aimed to investigate the effect of histamine‐3 (H3) receptors, expressed in the tuberomammillary nucleus (TMN) of the hypothalamus and in the prefrontal cortex (PFC), on histamine neurotransmission in the rat brain. The firing activity of histamine neurons in the TMN was measured using in vivo extracellular single‐unit electrophysiology, under propofol anesthesia. Extracellular histamine levels were determined using the dual (PFC and TMN) probe microdialysis, in freely‐moving animals. Histamine levels in dialysates were determined using high‐performance liquid chromatography (HPLC) and fluorescence detection. It was found that systemic administration of the selective H3‐agonist, immepip, decreases, and the reverse H3/H4‐agonist, thioperamide, increases... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5378131 Tue, 01 Nov 2011 04:00:00 +0100 5378131 http://www.medworm.com/index.php?rid=5332711&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07873.x AbstractThe striatum harbors a small number of tyrosine hydroxylase (TH) mRNA‐containing GABAergic neurons that express TH immunoreactivity after dopamine depletion, some of which reportedly resembled striatal medium spiny projection neurons (MSNs). To clarify whether the TH mRNA‐expressing neurons were a subset of MSNs, we characterized their postnatal development of electrophysiological and morphological properties using a transgenic mouse strain expressing enhanced green fluorescent protein (EGFP) under the control of the rat TH gene promoter. At postnatal day (P)1, EGFP‐TH+ neurons were present as clusters in the striatum and, thereafter, gradually scattered ventromedially by P18 without regard to the striatal compartments. They were immunonegative for calbindin, but immunopositi... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332711 Mon, 17 Oct 2011 04:00:00 +0100 5332711 http://www.medworm.com/index.php?rid=5332710&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07870.x AbstractPrevious studies with transcranial magnetic stimulation (TMS) have shown that advancing age may influence plasticity induction in human motor cortex (M1), but these changes have been assessed with TMS‐induced paradigms or simple motor tasks. The aim of this study was to examine changes in corticospinal excitability and intracortical inhibition as markers of corticomotor plasticity following complex motor training in young and old adults. Electromyographic recordings were obtained from the right first dorsal interosseous (FDI) muscle of 16 young (20–35 years) and 16 older (aged 60–75 years) adults before and after motor skill training. Motor training consisted of three 6‐minute blocks of a complex visuomotor task that required matching the metacarpophalangeal (MCP) joint... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332710 Mon, 17 Oct 2011 04:00:00 +0100 5332710 http://www.medworm.com/index.php?rid=5332709&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07848.x This study reveals the unconscious cognitive dimension evoked by food flavours according to the individual experience, and highlights the importance of the food sensory image on hedonism and anticipatory eating behaviour.We describe the behavioural consequences of conditioned flavour aversion and preference in pigs and have investigated the brain circuits involved in the representation of flavours with different hedonic values. The study was performed on eight 30‐kg pigs. (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332709 Mon, 17 Oct 2011 04:00:00 +0100 5332709 http://www.medworm.com/index.php?rid=5322302&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07847.x We examined COVIS in an fMRI study with two novel (in terms of COVIS research) categorizations. One of the categorizations could be described by a simple, unidimensional, rule that was expected to favor the verbal system. The other categorization possessed characteristics typically associated with the procedural system, but could also potentially be verbalized using a rule more complex than the ones previously associated with the verbal system. We found that both categorizations engaged regions associated with the verbal system. Additionally, for both categorizations, frontal lobe regions (including left ventrolateral frontal cortex) were more engaged in the first compared to the second session, possibly reflecting the greater use of hypothesis‐testing processes in the initial stages of ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322302 Thu, 13 Oct 2011 04:00:00 +0100 5322302 http://www.medworm.com/index.php?rid=5322301&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07855.x This study documented the regional and quantitative shape difference of cortical surfaces for in utero normal fetal brains over a time period essential for the formation of primary cortical folding (22–33 weeks). Each brain surface with complete three‐dimensional morphology was manually extracted from the reconstructed image, which combined surface information from three orthogonal magnetic resonance images in utero. An innovative parcellation was used to dissect the fetal brains into frontal, parietal, temporal and occipital lobes, and to avoid the determination of non‐existent and immature sulci for young fetuses. Distinct cortical shapes were encoded by the shape index automatically. The results of this study show faster shape changes in the occipital lobe than in other regions.... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322301 Thu, 13 Oct 2011 04:00:00 +0100 5322301 http://www.medworm.com/index.php?rid=5322300&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07862.x AbstractTo encourage re‐establishment of functional innervation of ipsilateral lumbar motoneurons by descending fibers after an intervening lateral thoracic (T10) hemisection (Hx), we treated adult rats with the following agents: (i) anti‐Nogo‐A antibodies to neutralize the growth‐inhibitor Nogo‐A; (ii) neurotrophin‐3 (NT‐3) via engineered fibroblasts to promote neuron survival and plasticity; and (iii) the NMDA‐receptor 2d (NR2d) subunit via an HSV‐1 amplicon vector to elevate NMDA receptor function by reversing the Mg2+ block, thereby enhancing synaptic plasticity and promoting the effects of NT‐3. Synaptic responses evoked by stimulation of the ventrolateral funiculus ipsilateral and rostral to the Hx were recorded intracellularly from ipsilateral lumbar motoneurons.... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322300 Thu, 13 Oct 2011 04:00:00 +0100 5322300 http://www.medworm.com/index.php?rid=5322299&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07856.x AbstractIndependent component analysis (ICA) can be usefully applied to functional imaging studies to evaluate the spatial extent and temporal profile of task‐related brain activity. It requires no a priori assumptions about the anatomical areas that are activated or the temporal profile of the activity. We applied spatial ICA to detect a voluntary but hidden response of silent speech. To validate the method against a standard model‐based approach, we used the silent speech of a tongue twister as a ‘Yes’ response to single questions that were delivered at given times. In the first task, we attempted to estimate one number that was chosen by a participant from 10 possibilities. In the second task, we increased the possibilities to 1000. In both tasks, spatial ICA was as effective as... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322299 Thu, 13 Oct 2011 04:00:00 +0100 5322299 http://www.medworm.com/index.php?rid=5322298&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07857.x In this study, we examined whether ethanol‐mediated regulation of NR1 mRNA in vivo is similar to that in vitro and whether Δ4–trans interactions are important for ethanol‐mediated NR1 mRNA stability. Our data show that polysomal proteins from adult mouse cerebral cortex (CC) formed a complex with Δ4 RNA, suggesting the presence of NR1 mRNA‐binding trans‐acting proteins in CC polysomes. The intensity of the Δ4 RNA–protein complex was increased with polysomes from chronic ethanol‐exposed CC. The Δ4 RNA–protein complex harbored GIIβ and a second trans‐acting protein identified as annexin A2 (AnxA2). Ethanol‐sensitive GIIβ was upregulated by 70% in ethanol‐exposed CC. Heparin, a known binding partner of AnxA2, inhibited Δ4 RNA–protein complex formation. Trans... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322298 Thu, 13 Oct 2011 04:00:00 +0100 5322298 http://www.medworm.com/index.php?rid=5302440&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07849.x This study tested the effects of manipulating S1 excitability with paired associative transcranial stimulation (S1‐PAS) on M1 excitability. Given the important role of S1 in sensorimotor integration, we hypothesized that changes in S1 excitability would be directly paralleled by changes in M1 excitability. We applied two established protocols (S1‐PASLTP and S1‐PASLTD) to the left S1 to induce long‐term potentiation (LTP)‐like or long‐term depression (LTD)‐like plasticity. S1 excitability was assessed by the early cortical components (N20–P25) of the median nerve somatosensory‐evoked potential. M1 excitability was assessed by motor‐evoked potential amplitude and short‐interval intracortical inhibition. Effects of S1‐PASLTP were compared with those of a PASLTP protoco... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5302440 Thu, 06 Oct 2011 04:00:00 +0100 5302440 http://www.medworm.com/index.php?rid=5302439&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07859.x AbstractFunctional imaging studies show that vestibular and somatosensory projections overlap in the human brain. However, it remains unclear whether and how vestibular inputs affect somatosensory function. To address this issue, we studied the effects of left caloric vestibular stimulation (CVS) on detection of near‐threshold somatosensory stimuli delivered to the left and right hands of healthy volunteers. To investigate whether these effects were somatosensory specific, or supramodal, we also tested CVS modulation of visual contrast detection. Signal detection analyses showed increased somatosensory perceptual sensitivity immediately after CVS, both ipsilaterally and contralaterally. No statistically reliable effects on visual contrast sensitivity were found. These findings suggest th... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5302439 Thu, 06 Oct 2011 04:00:00 +0100 5302439 http://www.medworm.com/index.php?rid=5302438&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07863.x AbstractPsychological stress‐induced hyperthermia is a fundamental autonomic response in mammals. However, the central circuitry underlying this stress response is poorly understood. Here, we sought to identify sympathetic premotor neurons that mediate a hyperthermic response to social defeat stress, a psychological stress model. Intruder rats that were defeated by a dominant resident conspecific exhibited a rapid increase in abdominal temperature by up to 2.0 °C. In these defeated rats, we found that expression of Fos, a marker of neuronal activation, was increased in the rostral medullary raphe region centered in the rostral raphe pallidus and adjacent raphe magnus nuclei. In this region, Fos expression was observed in a large population of neurons expressing vesicular glutamate tra... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5302438 Thu, 06 Oct 2011 04:00:00 +0100 5302438 http://www.medworm.com/index.php?rid=5344805&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07885.x AbstractIn the monkey posterior parietal cortex (PPC), there is clear evidence of anatomically segregated neuronal populations specialized for planning saccades and arm‐reaching movements. However, functional neuroimaging studies in humans have yielded controversial results. Here we show that the human PPC contains distinct subregions responsive to salient visual cues, some of which combine spatial and action‐related signals into ‘intentional’ signals. Participants underwent event‐related functional magnetic resonance imaging while performing delayed saccades and long‐range arm reaches instructed by visual cues. We focused on activity in the time period following the cue and preceding the actual movement. The use of individual cortical surface reconstructions with detailed sulc... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5344805 Sat, 01 Oct 2011 04:00:00 +0100 5344805 http://www.medworm.com/index.php?rid=5332713&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07913.x (Source: European Journal of Neuroscience) European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332713 Sat, 01 Oct 2011 04:00:00 +0100 5332713 http://www.medworm.com/index.php?rid=5332712&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07853.x AbstractThe serine protease subtilisin‐A (SubA) induces a form of long‐term depression (LTD) of synaptic transmission in the rat hippocampus, and molecular changes associated with SubA‐induced LTD (SubA‐LTD) were explored by using recordings of evoked postsynaptic potentials and immunoblotting. SubA‐LTD was prevented by a selective inhibitor of SubA proteolysis, but the same inhibitor did not affect LTD induced by electrical stimulation or activation of metabotropic glutamate receptors. SubA‐LTD was reduced by the protein kinase inhibitors genistein and lavendustin A, although not by inhibitors of p38 mitogen‐activated protein kinase, glycogen synthase kinase‐3, or protein phosphatases. It was also reduced by (RS)‐α‐methyl‐4‐carboxyphenylglycine, a broad‐spectrum... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332712 Sat, 01 Oct 2011 04:00:00 +0100 5332712 http://www.medworm.com/index.php?rid=5332708&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07861.x AbstractMutation of the gene encoding carbonic anhydrase‐related protein VIII (CAVIII) results in motor coordination deficits in mice and humans, due to loss of this protein in Purkinje cells of the cerebellum. Recent studies have indicated that the CAVIII gene, Car8, is also expressed in rod bipolar cells (RBCs), a critical glutamatergic neuron for scotopic vision. We investigated the localization of CAVIII in the mouse and macaque retina, and utilized the wdl mouse, which has a null mutation in the Car8 gene, to determine how the loss of CAVIII affects retinal signaling. CAVIII immunoreactivity was observed in RBCs, with particularly high staining intensity in the axon terminals. In addition, weaker staining was observed in a subset of cone bipolar cells and γ‐aminobutyric acid (GAB... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5332708 Sat, 01 Oct 2011 04:00:00 +0100 5332708 http://www.medworm.com/index.php?rid=5322297&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07852.x AbstractIn mice, the matrix compartment of the striatum (caudate/putamen) undergoes major developmental changes during the second postnatal week, including the establishment of corticostriatal and nigrostriatal afferents, the maturation of parvalbumin‐positive interneurons and the appearance of perineuronal nets. It is not known if any of these events influence the dendritic structure of medium spiny neurons, the principal output cells of the striatum. To determine whether any measurable changes in the dendrites of matrix medium spiny neurons occur during this important developmental period, we labeled individual cells at different time points flanking the second postnatal week. These cells exhibit distinct dendritic morphologies from the earliest postnatal time points examined. Furtherm... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5322297 Sat, 01 Oct 2011 04:00:00 +0100 5322297 http://www.medworm.com/index.php?rid=5302437&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07858.x AbstractIncreased levels of glutamate causing excitotoxic damage accompany neurological disorders such as ischemia/stroke, epilepsy and some neurodegenerative diseases. Cyclin‐dependent kinase‐5 (Cdk5) is important for synaptic plasticity and is deregulated in neurodegenerative diseases. However, the mechanisms by which kainic acid (KA)‐induced excitotoxic damage involves Cdk5 in neuronal injury are not fully understood. In this work, we have thus studied involvement of Cdk5 in the KA‐mediated degeneration of glutamatergic synapses in the rat hippocampus. KA induced degeneration of mossy fiber synapses and decreased glutamate receptor (GluR)6/7 and post‐synaptic density protein 95 (PSD95) levels in rat hippocampus in vivo after intraventricular injection of KA. KA also increase... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5302437 Sat, 01 Oct 2011 04:00:00 +0100 5302437 http://www.medworm.com/index.php?rid=5282788&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07834.x In this study we investigate mechanisms underlying the increased susceptibility to acoustic startle in a mouse model homozygous for the spontaneous megencephaly (mceph) mutation, which results in a lack of the functional potassium channel Kv1.1. Mceph mice are hypersensitive to acoustic startle, a response that is not seen in the wild‐type (WT) littermates. After acoustic startle, a strong activation of astrocytes, as indicated by glial fibrillary acidic protein, occurred in the inferior colliculus and hippocampus. Both the hypersensitivity of acoustic startle as well as activation of astrocytes could be maintained at WT levels by pre‐treating the Mceph mice with the anti‐epileptic drug valproate. Furthermore, we utilized the Mceph mouse model to investigate whether acoustic startle�... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5282788 Sat, 01 Oct 2011 04:00:00 +0100 5282788 http://www.medworm.com/index.php?rid=5247648&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07850.x AbstractThe ease with which humans are able to perform symmetric movements of both hands has traditionally been attributed to the preference of the motor system to activate homologous muscles. Recently, we have shown in right‐handers, however, that bimanual index finger adduction and abduction movements in incongruous hand orientations (one palm down/other up) preferentially engaged parietal perception‐associated brain areas. Here, we used functional magnetic resonance imaging to investigate the influence of hand orientation in left‐handers on cerebral activation during bimanual index finger movements. Performance in incongruous orientation of either hand yielded activations involving right and left motor cortex, supplementary motor area in right superior frontal gyrus (SMA and pre�... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5247648 Wed, 21 Sep 2011 04:00:00 +0100 5247648 http://www.medworm.com/index.php?rid=5247647&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07864.x AbstractIn previous studies, we have shown that by increasing the brain‐to‐blood glutamate efflux upon scavenging blood glutamate with either oxaloacetate or pyruvate, one achieves highly significant neuroprotection particularly in the context of traumatic brain injury. The current study examines, for the first time, how the blood glutamate scavenging properties of glutamate–pyruvate transaminase (GPT), alone or in combination with pyruvate, may contribute to the spectrum of its neuroprotective mechanisms and improve the outcome of rats exposed to brain ischemia, as they do after head trauma. Rats that were exposed to permanent middle cerebral artery occlusion (MCAO) and treated with intravenous 250 mg/kg pyruvate had a smaller volume of infarction and reduced brain edema, resultin... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5247647 Wed, 21 Sep 2011 04:00:00 +0100 5247647 http://www.medworm.com/index.php?rid=5247646&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07840.x AbstractSeveral studies have revealed that manipulation of the renin angiotensin system results in reduced progression of nigrostriatal damage in different animal models of Parkinson’s disease. In the present work, the effect of daily treatment of rats with the angiotensin II (Ang II) type 1 (AT1) receptor antagonist candesartan (3 mg/kg per day, s.c.) initiated 7 days before the intrastriatal injection of 6‐hydroxydopamine (6‐OHDA) was investigated by means of tyrosine hydroxylase‐positive cell counts in the substantia nigra, and dopamine and 3,4‐dihydroxyphenylacetic acid measurements in the striatum. In this experimental set‐up, candesartan protected dopaminergic neurons of the nigrostriatal tract against the neurotoxin‐induced cell death. However, the beneficial effec... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5247646 Wed, 21 Sep 2011 04:00:00 +0100 5247646 http://www.medworm.com/index.php?rid=5247645&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07846.x AbstractNeurotensin (NT) is a neuropeptide involved in the modulation of nociception. We have investigated the actions of NT on cultured postnatal rat spinal cord dorsal horn (DH) neurons. NT induced an inward current associated with a decrease in membrane conductance in 46% of the neurons and increased the frequency of glutamatergic miniature excitatory synaptic currents in 37% of the neurons. Similar effects were observed in acute slices. Both effects of NT were reproduced by the selective NTS1 agonist JMV449 and blocked by the NTS1 antagonist SR48692 and the NTS1/NTS2 antagonist SR142948A. The NTS2 agonist levocabastine had no effect. The actions of NT persisted after inactivation of Gi/o proteins by pertussis toxin but were absent after inactivation of protein kinase C (PKC) by chelery... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5247645 Wed, 21 Sep 2011 04:00:00 +0100 5247645 http://www.medworm.com/index.php?rid=5247644&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07786.x AbstractThe pathological basis of neonatal hypoxia–ischemia (HI) brain damage is characterized by neuronal cell loss. Oxidative stress is thought to be one of the main causes of HI‐induced neuronal cell death. The p38 mitogen‐activated protein kinase (MAPK) is activated under conditions of cell stress. However, its pathogenic role in regulating the oxidative stress associated with HI injury in the brain is not well understood. Thus, this study was conducted to examine the role of p38 MAPK signaling in neonatal HI brain injury using neonatal rat hippocampal slice cultures exposed to oxygen/glucose deprivation (OGD). Our results indicate that OGD led to a transient increase in p38 MAPK activation that preceded increases in superoxide generation and neuronal death. This increase in neur... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5247644 Wed, 21 Sep 2011 04:00:00 +0100 5247644 http://www.medworm.com/index.php?rid=5205484&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07830.x AbstractAmple evidence suggests that, when reactivated by a reminder, a consolidated memory may return to a labile state and needs to be stabilized again in order to persist, a process known as reconsolidation. In a previous study, performed in the crab Chasmagnathus, we found a dual role for the biogenic amine octopamine (OA) during memory consolidation. On the one hand, it was necessary for appetitive memory formation and, on the other, it had a deleterious effect on aversive memory consolidation. Thus, OA could be a good candidate to dissect the neurochemical mechanisms of appetitive and aversive reconsolidation. Here, we initially characterized the reconsolidation of an appetitive memory. Then, we compared appetitive reconsolidation with its aversive counterpart regarding the implicati... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205484 Wed, 07 Sep 2011 04:00:00 +0100 5205484 http://www.medworm.com/index.php?rid=5205483&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07821.x AbstractSpecialized populations of choroid plexus epithelial cells have previously been shown to be responsible for the transfer of individual plasma proteins from blood to the cerebrospinal fluid (CSF), contributing to their characteristically high concentrations in CSF of the developing brain. The mechanism of this protein transfer remains elusive. Using a marsupial, Monodelphis domestica, we demonstrate that the albumin‐binding protein SPARC (osteonectin/BM‐40/culture‐shock protein) is present in a subset of choroid plexus epithelial cells from its first appearance, throughout development, and into adulthood. The synthesis of SPARC by the lateral ventricular plexus was confirmed with real‐time PCR. The expression level of SPARC was higher in plexuses of younger than older animal... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205483 Wed, 07 Sep 2011 04:00:00 +0100 5205483 http://www.medworm.com/index.php?rid=5205482&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07825.x AbstractBrainstem respiratory neurons express the glycine α3 receptor (Glyα3R), which is a target of modulation by several serotonin (5‐HT) receptor agonists. Application of the 5‐HT1A receptor (5‐HT1AR) agonist 8‐OH‐DPAT was shown (i) to depress cellular cAMP, leading to dephosphorylation of Glyα3R and augmentation of postsynaptic inhibition of neurons expressing Glyα3R (Manzke et al., 2010) and (ii) to hyperpolarize respiratory neurons through 5‐HT‐activated potassium channels. These processes counteract opioid‐induced depression and restore breathing from apnoeas often accompanying pharmacotherapy of pain. The effect is postulated to rely on the enhanced Glyα3R‐mediated inhibition of inhibitory neurons causing disinhibition of their target neurons. To evaluate th... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205482 Wed, 07 Sep 2011 04:00:00 +0100 5205482 http://www.medworm.com/index.php?rid=5205481&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07836.x AbstractThe tumor suppressor protein p53 (Trp53) and the cell cycle inhibitor p27 Kip1 (Cdknb1) have both been implicated in regulating proliferation of adult subventricular zone (aSVZ) cells. We previously reported that genetic ablation of Trp53 (Trp53 −/−) or Cdknb1 (p27 Kip1−/−) increased proliferation of cells in the aSVZ, but differentially affected the number of adult born neuroblasts. We therefore hypothesized that these molecules might play non‐redundant roles. To test this hypothesis we generated mice lacking both genes (Trp53 −/−;p27 Kip1−/−) and analysed the consequences on aSVZ cells and adult neuroblasts. Proliferation and self‐renewal of cultured aSVZ cells were increased in the double mutants compared with control, but the mice did not develop s... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205481 Wed, 07 Sep 2011 04:00:00 +0100 5205481 http://www.medworm.com/index.php?rid=5205490&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07822.x AbstractSchizophrenia is associated with a wide range of symptoms. These include auditory hallucinations, delusions, and experiences that one is not in control of one’s own thoughts and actions, but that they are inserted by an outside agency. It has been proposed that a disturbance in the sense of self may account for many of these symptoms. This disturbance in turn may be associated with source monitoring deficits. In other words, individuals with schizophrenia may misattribute the source of their own thoughts and actions to an outside agency, which then results in the experience of psychosis such as that of hearing voices. To explain the source monitoring deficits, it has been proposed that this illness involves impairment in corollary discharge mechanisms. Corollary discharge refers ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205490 Tue, 06 Sep 2011 04:00:00 +0100 5205490 http://www.medworm.com/index.php?rid=5205489&cid=s_32222_168_f&fid=32222&url=http%3A%2F%2Fdx.doi.org%2F10.1111%252Fj.1460-9568.2011.07837.x AbstractThe raphe pallidus (RPa) and Bötzinger complex (BötC) represent two important nuclei which project to spinal phrenic motor neurons. Stimulation of the RPa produces facilitative effects on respiratory activity, whereas stimulation of the BötC induces inhibitory effects on respiratory activity. In the present study, we examined the modulatory effects of serotonergic (5‐hydroxytryptamine, 5‐HT) RPa neurons on the inhibitory response of the phrenic nerve activity elicited from the BötC in rats. Experiments were performed on spontaneously breathing, urethane‐anesthetized adult rats. Either high‐frequency stimulation or glutamatergic chemical activation of the RPa region significantly attenuated the BötC‐induced inhibition of the phrenic nerve. This attenuation showed a ... European Journal of Neuroscience journals http://www.medworm.com/rss/comments.php?id=5205489 Tue, 06 Sep 2011 04:00:00 +0100 5205489