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CorrigendumEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Tags: Corrigenda Source Type: journals

Are There Nociceptive-Specific Brain Potentials? Reply to Baumgartner and TreedeEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Mouraux, A., Plaghki, L., Iannetti, G. D. Tags: Letter to the Editor Source Type: journals

Are There Nociceptive-Specific Brain Potentials?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Baumgartner, U., Treede, R.-D. Tags: Letter to the Editor Source Type: journals

Characterizing Learning by Simultaneous Analysis of Continuous and Binary Measures of PerformanceEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We present a state-space model of learning in which the observation process has simultaneously recorded continuous and binary measures of performance. We use these performance measures simultaneously to estimate the model parameters and the unobserved cognitive state process by maximum likelihood using an approximate expectation maximization (EM) algorithm. We introduce the concept of a reaction-time curve and reformulate our previous definitions of the learning curve, the ideal observer curve, the learning trial and between-trial comparisons of performance in terms of the new model. We illustrate the properties of the new...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Prerau, M. J., Smith, A. C., Eden, U. T., Kubota, Y., Yanike, M., Suzuki, W., Graybiel, A. M., Brown, E. N. Tags: Innovative Methodology Source Type: journals

EEG Generator--A Model of Potentials in a Volume ConductorEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we first suggest a new definition of the EEG generator. We use the theory of potentials in a volume conductor and model the contribution of a single synapse activated to the surface potential. We then model the contribution of the generator to the surface potential. Once the generator and its contribution are well defined, we can quantitatively assess the degree of synchronization among generators. The measures obtained by the model for a real life scenario of a group of generators organized in a specific statistical way were consistent with the expected values that were reported experimentally. The study sh...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Avitan, L., Teicher, M., Abeles, M. Tags: Articles Source Type: journals

Excitatory and Inhibitory Synapses in Neuropeptide Y-Expressing Striatal InterneuronsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Although rare, interneurons are pivotal in governing striatal output by extensive axonal arborizations synapsing on medium spiny neurons. Using a genetically modified mouse strain in which a green fluorescent protein (GFP) is driven to be expressed under control of the neuropeptide Y (NPY) promoter, we identified NPY interneurons and compared them with striatal principal neurons. We found that the bacteria artificial chromosome (BAC)-npy mouse expresses GFP with high fidelity in the striatum to the endogenous expression of NPY. Patch-clamp analysis from NPY neurons showed a heterogeneous population of striatal interneurons...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Partridge, J. G., Janssen, M. J., Chou, D. Y. T., Abe, K., Zukowska, Z., Vicini, S. Tags: Articles Source Type: journals

Transient Firing of Dorsal Raphe Neurons Encodes Diverse and Specific Sensory, Motor, and Reward EventsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Serotonin (5-hydroxytryptamine [5-HT]) is known to influence a wide range of behaviors and physiological processes, but relatively little is known about events that trigger 5-HT release. To address this issue, we recorded from neurons in the dorsal raphe nucleus (DRN) in rats performing an odor-guided spatial decision task. A large fraction of DRN neurons showed transient firing time locked to behavioral events on timescales as little as 20 ms. DRN transients were sometimes correlated with reward parameters, but also encoded specific sensorimotor events, including stimulus identity and response direction. These behavioral ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Ranade, S. P., Mainen, Z. F. Tags: Articles Source Type: journals

Type of Featural Attention Differentially Modulates hMT+ Responses to Illusory Motion AftereffectsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Activity in the human motion complex (hMT+/V5) is related to the perception of motion, be it either real surface motion or an illusion of motion such as apparent motion (AM) or motion aftereffect (MAE). It is a long-lasting debate whether illusory motion-related activations in hMT+ represent the motion itself or attention to it. We have asked whether hMT+ responses to MAEs are present when shifts in arousal are suppressed and attention is focused on concurrent motion versus nonmotion features. Significant enhancement of hMT+ activity was observed during MAEs when attention was focused either on concurrent spatial angle or ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Castelo-Branco, M., Kozak, L. R., Formisano, E., Teixeira, J., Xavier, J., Goebel, R. Tags: Articles Source Type: journals

Long-Latency Responses During Reaching Account for the Mechanical Interaction Between the Shoulder and Elbow JointsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Although considerable research indicates that reaching movements rely on knowledge of the arm's mechanical properties and environment to anticipate and counter predictable loads, far less research has examined whether this degree of sophistication is present for on-line corrections during reaching. Here we examine the R2/3 response to mechanical perturbations (45–100 ms, also called the long-latency reflex), which is highly flexible and includes the fastest possible contribution from primary motor cortex, a key neural substrate for self-initiated action. Torque perturbations were occasionally and unexpectedly applied...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Kurtzer, I., Pruszynski, J. A., Scott, S. H. Tags: Articles Source Type: journals

Functional Asymmetries Revealed in Visually Guided Saccades: An fMRI StudyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Because eye movements are a fundamental tool for spatial exploration, we hypothesized that the neural bases of these movements in humans should be under right cerebral dominance, as already described for spatial attention. We used functional magnetic resonance imaging in 27 right-handed participants who alternated central fixation with either large or small visually guided saccades (VGS), equally performed in both directions. Hemispheric functional asymmetry was analyzed to identify whether brain regions showing VGS activation elicited hemispheric asymmetries. Hemispheric anatomical asymmetry was also estimated to assess i...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Petit, L., Zago, L., Vigneau, M., Andersson, F., Crivello, F., Mazoyer, B., Mellet, E., Tzourio-Mazoyer, N. Tags: Articles Source Type: journals

Direct Activation and Temporal Response Properties of Rabbit Retinal Ganglion Cells Following Subretinal StimulationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study used cell-attached and whole cell current-clamp recordings to investigate the responses of rabbit retinal ganglion cells (RGCs) following subretinal stimulation with 25-µm-diameter electrodes. We found that direct RGC responses with short latency (≤2 ms using 0.1-ms pulses) could be reliably elicited. The thresholds for these responses were reported for on, off, and on–off RGCs over pulse widths 0.1–5.0 ms. During repetitive stimulation these direct activation responses were more readily elicited than responses arising from stimulation of the retinal network. The temporal spiking characteris...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Tsai, D., Morley, J. W., Suaning, G. J., Lovell, N. H. Tags: Articles Source Type: journals

Radial Biases in the Processing of Motion and Motion-Defined Contours by Human Visual CortexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Luminance gratings reportedly produce a stronger functional magnetic resonance imaging (fMRI) blood oxygen level–dependent (BOLD) signal in those parts of the retinotopic cortical maps where they are oriented radially to the point of fixation. We sought to extend this finding by examining anisotropies in the response of cortical areas V1–V3 to motion-defined contour stimuli. fMRI at 3 Tesla was used to measure the BOLD signal in the visual cortex of six human subjects. Stimuli were composed of strips of spatial white noise texture presented in an annular window. The texture in alternate strips moved in opposite...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Clifford, C. W. G., Mannion, D. J., McDonald, J. S. Tags: Articles Source Type: journals

Experience-Dependent Intrinsic Plasticity in Interneurons of Barrel Cortex Layer IVEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
It is unclear whether intrinsic excitabilities of specific interneurons are modulated by sensory experiences. Here, I examined the intrinsic excitabilities of interneurons in "sensory-spared" and "sensory-deprived" cortices of GAD67-GFP mice. The results showed that whisker trimming, begun at postnatal day 7 for 3 wk, induced significant changes in intrinsic and firing properties of fast-spiking (FS) but not regular spiking nonpyramidal (RSNP) cells. Firing threshold, spike frequency, spike adaptation index, and input resistance of FS cells were significantly altered by sensory deprivation such that FS cells became less ex...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Sun, Q.-Q. Tags: Articles Source Type: journals

Substantia Nigra Output to Prefrontal Cortex Via Thalamus in Monkeys. II. Activity of Thalamic Relay Neurons in Delayed Conditional Go/No-Go Discrimination TaskEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The present report investigated the involvement of primate nigro-thalamo-cortical projections in discrimination of visual signals with behavioral meaning. We tested the extracellular unit activity of mediodorsal (MD) and ventral anterior (VA) thalamic neurons monosynaptically receiving inhibitory input from the substantia nigra pars reticulata (SNr) and projecting to the frontal cortex in Japanese monkeys performing a delayed conditional go/no-go discrimination task. In the task two colored stimuli (S1, S2) intervened by delay period required the monkeys lifting a lever (go) or not (no-go); the same and different colored p...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Tanibuchi, I., Kitano, H., Jinnai, K. Tags: Articles Source Type: journals

Substantia Nigra Output to Prefrontal Cortex Via Thalamus in Monkeys. I. Electrophysiological Identification of Thalamic Relay NeuronsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study examined them in nigro-thalamo-cortical pathways from the substantia nigra pars reticulata (SNr) to the frontal cortex (FRC) via the mediodorsal (MD) and ventral anterior (VA) thalamus in monkeys. First, single thalamocortical neurons with SNr input were identified by antidromic responses to FRC stimulation and by inhibitory orthodromic responses with short latencies (<5 ms) to SNr stimulation. Second, single nigrothalamic neurons were found by antidromic responses to stimulation of the portions of the MD and VA where the thalamocortical neurons were recorded. The inhibitory orthodromic responses in the thala...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Tanibuchi, I., Kitano, H., Jinnai, K. Tags: Articles Source Type: journals

Adaptation to Visuomotor Rotation Through Interaction Between Posterior Parietal and Motor Cortical AreasEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Studying how motor adaptation to visuomotor rotation for one reach direction generalizes to other reach directions can provide insight into how visuomotor maps are represented and learned in the brain. Previous psychophysical studies have concluded that postadaptation generalization is restricted to a narrow range of directions around the training direction. A population-coding model that updates the weights between narrow Gaussian-tuned visual units and motor units on each trial reproduced experimental trial-by-trial learning curves for rotation adaptation and the generalization function measured postadaptation. These res...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Tanaka, H., Sejnowski, T. J., Krakauer, J. W. Tags: Articles Source Type: journals

Postural Feedback Scaling Deficits in Parkinson's DiseaseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Many differences in postural responses have been associated with age and Parkinson's disease (PD), but until now there has been no quantitative model to explain these differences. We developed a feedback control model of body dynamics that could reproduce the postural responses of young subjects, elderly subjects, and subjects with PD, and we investigated whether the postural impairments of subjects with PD can be described as an abnormal scaling of postural feedback gain. Feedback gains quantify how the nervous system generates compensatory joint torques based on kinematic responses. Seven subjects in each group experienc...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Kim, S., Horak, F. B., Carlson-Kuhta, P., Park, S. Tags: Articles Source Type: journals

Area Summation in Human Visual System: Psychophysics, fMRI, and ModelingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Contextual modulation is a fundamental feature of sensory processing, both on perceptual and on single-neuron level. When the diameter of a visual stimulus is increased, the firing rate of a cell typically first increases (summation field) and then decreases (surround field). Such an area summation function draws a comprehensive profile of the receptive field structure of a neuron, including areas outside the classical receptive field. We investigated area summation in human vision with psychophysics and functional magnetic resonance imaging (fMRI). The stimuli were similar to those used drifting sine wave gratings in prev...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Nurminen, L., Kilpelainen, M., Laurinen, P., Vanni, S. Tags: Articles Source Type: journals

Multicomponent Control Strategy Underlying Production of Maximal Hand Velocity During Horizontal Arm SwingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Movement control responsible for generation of maximal hand velocity was studied on the example of horizontal arm swing that is a component of various sports activities. The movement was performed with the nondominant arm in similarity with the baseball bat swing. The task was to generate maximum hand velocity at a target. The movement included trunk long-axis rotation and horizontal shoulder and elbow extension. Kinematics and torque analyses were performed to study the organization of fastest movements and to compare trials representing the best and worst performance in each subject. Results revealed complex control stra...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Kim, Y.-K., Hinrichs, R. N., Dounskaia, N. Tags: Articles Source Type: journals

Maintenance of Thalamic Epileptiform Activity Depends on the Astrocytic Glutamate-Glutamine CycleEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The generation of prolonged neuronal activity depends on the maintenance of synaptic neurotransmitter pools. The astrocytic glutamate-glutamine cycle is a major mechanism for recycling the neurotransmitters GABA and glutamate. Here we tested the effect of disrupting the glutamate-glutamine cycle on two types of neuronal activity patterns in the thalamus: sleep-related spindles and epileptiform oscillations. In recording conditions believed to induce glutamine scarcity, epileptiform oscillations showed a progressive reduction in duration that was partially reversible by the application of exogenous glutamine (300 µM)....
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Bryant, A. S., Li, B., Beenhakker, M. P., Huguenard, J. R. Tags: Articles Source Type: journals

Differential Activation of Projection Neurons by Two Sensory Pathways Contributes to Motor Pattern SelectionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Sensorimotor integration is known to occur at the level of motor circuits as well as in upstream interneurons that regulate motor activity. Here we show, using the crab stomatogastric nervous system (STNS) as a model, that different sensory systems affect the same set of projection neurons. However, they have qualitatively different effects on their activities (excitation vs. inhibition), and these differences contribute to the selection of motor patterns from multifunctional circuits. We compare the actions of the proprioceptive anterior gastric receptor (AGR) and the inferior ventricular (IV) neurons, which relay chemose...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Hedrich, U. B. S., Smarandache, C. R., Stein, W. Tags: Articles Source Type: journals

Bilateral Limb Phase Relationship and Its Potential to Alter Muscle Activity Phasing During LocomotionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
It is well established that the sensorimotor state of one limb can influence another limb and therefore bilateral somatosensory inputs make an important contribution to interlimb coordination patterns. However, the relative contribution of interlimb pathways for modifying muscle activation patterns in terms of phasing is less clear. Here we studied adaptation of muscle activity phasing to the relative angular positions of limbs using a split-crank ergometer, where the cranks could be decoupled to allow different spatial angular position relationships. Twenty neurologically healthy individuals performed the specified pedali...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Alibiglou, L., Lopez-Ortiz, C., Walter, C. B., Brown, D. A. Tags: Articles Source Type: journals

Influence of Vagotomy on Monosynaptic Transmission at Second-Order Nucleus Tractus Solitarius SynapsesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Manipulations of vagal activity are used to treat medical pathologies, but the underlying CNS changes caused by these treatments are not well understood. Furthermore, heart and lung transplant as well as treatments for many gastrointestinal disorders result in section of the vagus nerve (vagotomy). Following unilateral vagotomy under isoflurane anesthesia of Sprague-Dawley rats, electrophysiological properties were recorded with whole cell patch techniques in horizontal brain stem slices. Vagotomy significantly reduced the median amplitude of evoked excitatory postsynaptic currents (evEPSCs; –121; n = 43) in the nucl...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Swartz, J. B., Weinreich, D. Tags: Articles Source Type: journals

Distinct Electrophysiological Properties in Subtypes of Nonspiking Olfactory Local Interneurons Correlate With Their Cell Type-Specific Ca2+ Current ProfilesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A diverse population of local interneurons (LNs) helps to process, structure, and spatially represent olfactory information in the insect antennal lobe. In Periplaneta americana, we identified two subtypes of nonspiking local interneurons (type II LNs) by their distinct morphological and intrinsic electrophysiological properties. As an important step toward a better understanding of the cellular mechanisms that mediate odor information processing, we present a detailed analysis of their distinct voltage-activated Ca2+ currents, which clearly correlated with their distinct intrinsic electrophysiological properties. Both typ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Husch, A., Paehler, M., Fusca, D., Paeger, L., Kloppenburg, P. Tags: Articles Source Type: journals

5-HT and GABA Modulate Intrinsic Excitability of Type I Interneurons in HermissendaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The sensory neurons (photoreceptors) in the visual system of Hermissenda are one site of plasticity produced by Pavlovian conditioning. A second site of plasticity produced by conditioning is the type I interneurons in the cerebropleural ganglia. Both photoreceptors and statocyst hair cells of the graviceptive system form monosynaptic connections with identified type I interneurons. Two proposed neurotransmitters in the graviceptive system, serotonin (5-HT) and -aminobutyric acid (GABA), have been shown to modify synaptic strength and intrinsic neuronal excitability in identified photoreceptors. However, the potential role...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Jin, N. G., Tian, L.-M., Crow, T. Tags: Articles Source Type: journals

Transfer of Dynamic Learning Across PosturesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
When learning a difficult motor task, we often decompose the task so that the control of individual body segments is practiced in isolation. But on re-composition, the combined movements can result in novel and possibly complex internal forces between the body segments that were not experienced (or did not need to be compensated for) during isolated practice. Here we investigate whether dynamics learned in isolation by one part of the body can be used by other parts of the body to immediately predict and compensate for novel forces between body segments. Subjects reached to targets while holding the handle of a robotic, fo...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Ahmed, A. A., Wolpert, D. M. Tags: Articles Source Type: journals

On the Open-Loop and Feedback Processes That Underlie the Formation of Trajectories During Visual and Nonvisual Locomotion in HumansEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We investigated the nature of the control mechanisms at work during goal-oriented locomotion. In particular, we tested the effects of vision, locomotor speed, and the presence of via points on the geometric and kinematic properties of locomotor trajectories. We first observed that the average trajectories recorded in visual and nonvisual locomotion were highly comparable, suggesting the existence of vision-independent processes underlying the formation of locomotor trajectories. Then by analyzing and comparing the variability around the average trajectories across different experimental conditions, we were able to demonstr...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Pham, Q.-C., Hicheur, H. Tags: Articles Source Type: journals

Generalization of Visuomotor Learning Between Bilateral and Unilateral ConditionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A long history of behavioral and physiological research has suggested that bilateral coordination invokes unique neural processes that are not involved in unilateral movements. This hypothesis predicts that motor learning should show limited transfer between unilateral and bilateral conditions, which is consistent with a recent finding that indicated partial, but not complete, transfer of learning between the two conditions. However, during learning of new motor skills, transformations must also be made between visual and proprioceptive coordinate systems, a process that may occur upstream to the processes that differentia...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Wang, J., Sainburg, R. L. Tags: Articles Source Type: journals

Question of Reference Frames: Visual Direction-Selective Neurons in the Accessory Optic System of GoldfishEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We investigated if visual direction-selective neurons in the pretectal area (APT) of goldfish (Carassius auratus auratus) preferred visual stimuli resulting from rotations around axes corresponding to the best responsive axes of the semicircular canals [optic flow that is consistent to a maximal activation of the horizontal canal pair (yaw), to a maximal activation of the right anterior/left posterior semicircular canal pair (RALP), and to a maximal activation of the left anterior/right posterior semicircular canal pair (LARP)]. Our sample of neurons recorded in the left pretectum had two preferred axes of rotation: first,...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Masseck, O. A., Hoffmann, K.-P. Tags: Articles Source Type: journals

Transformation in the Neural Code for Whisker Deflection Direction Along the Lemniscal PathwayEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A prominent characteristic of neurons in the whisker system is their selectivity to the direction in which a whisker is deflected. The aim of this study was to determine how information about whisker direction is encoded at successive levels of the lemniscal pathway. We made extracellular recordings under identical conditions from the trigeminal ganglion, ventro-posterior medial thalamus (VPM), and barrel cortex while varying the direction of whisker deflection. We found a marked increase in the variability of single unit responses along the pathway. To study the consequences of this for information processing, we quantifi...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Bale, M. R., Petersen, R. S. Tags: Articles Source Type: journals

Intrinsic Neuronal Excitability Is Reversibly Altered by a Single Experience in Fear ConditioningEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Learning is known to cause alterations in intrinsic cellular excitability but, to date, these changes have been seen only after multiple training trials. A powerful learning task that can be quickly acquired and extinguished with a single trial is fear conditioning. Rats were trained and extinguished on a hippocampus-dependent form of fear conditioning to determine whether learning-related changes in intrinsic excitability could be observed after a few training trials and a single extinction trial. Following fear training, hippocampal slices were made and intrinsic excitability was assayed via whole cell recordings from CA...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: McKay, B. M., Matthews, E. A., Oliveira, F. A., Disterhoft, J. F. Tags: Articles Source Type: journals

Changing the "When" and "What" of Intended ActionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Humans often have to modify the timing and/or type of their planned actions on the basis of new sensory information. In the present experiments, participants planned to make a right index finger keypress 3 s after a warning stimulus but on some trials were interrupted by a temporally unpredictable auditory tone prompting the same action (experiment 1) or a different action (experiment 2). In experiment 1, by comparing the reaction time (RT) to tones presented at different stages of the preparatory period to RT in a simple reaction time condition, we determined the cost of switching from an internally generated mode of resp...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Obhi, S. S., Matkovich, S., Chen, R. Tags: Articles Source Type: journals

Age-Related Declines in Visuospatial Working Memory Correlate With Deficits in Explicit Motor Sequence LearningEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Numerous studies have shown that older adults exhibit deficits in motor sequence learning, but the mechanisms underlying this effect remain unclear. Our recent work has shown that visuospatial working-memory capacity predicts the rate of motor sequence learning and the length of motor chunks formed during explicit sequence learning in young adults. In the current study, we evaluate whether age-related deficits in working memory explain the reduced rate of motor sequence learning in older adults. We found that older adults exhibited a correlation between visuospatial working-memory capacity and motor sequence chunk length, ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Bo, J., Borza, V., Seidler, R. D. Tags: Articles Source Type: journals

Neural Representations of Complex Temporal Modulations in the Human Auditory CortexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Natural sounds such as speech contain multiple levels and multiple types of temporal modulations. Because of nonlinearities of the auditory system, however, the neural response to multiple, simultaneous temporal modulations cannot be predicted from the neural responses to single modulations. Here we show the cortical neural representation of an auditory stimulus simultaneously frequency modulated (FM) at a high rate, fFM 40 Hz, and amplitude modulation (AM) at a slow rate, fAM <15 Hz. Magnetoencephalography recordings show fast FM and slow AM stimulus features evoke two separate but not independent auditory steady-state...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Ding, N., Simon, J. Z. Tags: Articles Source Type: journals

Brain Switch for Reflex Micturition Control Detected by fMRI in RatsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, functional magnetic resonance imaging (fMRI) was used to visualize the brain switching circuits controlling reflex micturition in anesthetized rats. The fMRI images confirmed the hypothesis based on previous neuroanatomical and neurophysiological studies that the brain stem switch for reflex micturition control involves both the periaqueductal gray (PAG) and the pontine micturition center (PMC). During storage, the PAG was activated by afferent input from the urinary bladder while the PMC was inactive. When bladder volume increased to the micturition threshold, the switch from storage to micturition was asso...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Tai, C., Wang, J., Jin, T., Wang, P., Kim, S.-G., Roppolo, J. R., de Groat, W. C. Tags: Articles Source Type: journals

Visual Field Maps, Population Receptive Field Sizes, and Visual Field Coverage in the Human MT+ ComplexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Human neuroimaging experiments typically localize motion-selective cortex (MT+) by contrasting responses to stationary and moving stimuli. It has long been suspected that MT+, located on the lateral surface at the temporal–occipital (TO) boundary, contains several distinct visual field maps, although only one coarse map has been measured. Using a novel functional MRI model–based method we identified two maps—TO-1 and TO-2—and measured population receptive field (pRF) sizes within these maps. The angular representation of the first map, TO-1, has a lower vertical meridian on its posterior side at the...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Amano, K., Wandell, B. A., Dumoulin, S. O. Tags: Articles Source Type: journals

Effects of Canal Plugging on the Vestibuloocular Reflex and Vestibular Nerve Discharge During Passive and Active Head RotationsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Mechanical occlusion (plugging) of the slender ducts of semicircular canals has been used in the clinic as well as in basic vestibular research. Here, we investigated the effect of canal plugging in two macaque monkeys on the horizontal vestibuloocular reflex (VOR) and the responses of vestibular-nerve afferents during passive head rotations. Afferent responses to active head movements were also studied. The horizontal VOR gain decreased after plugging to <0.1 for frequencies <2 Hz but rose to about 0.6 as frequency was increased to 15 Hz. Afferents innervating plugged horizontal canals had response sensitivities tha...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Sadeghi, S. G., Goldberg, J. M., Minor, L. B., Cullen, K. E. Tags: Articles Source Type: journals

Eye-Hand Coordination During Target Selection in a Pop-Out Visual SearchEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We examined the coordination of saccades and reaches in a visual search task in which monkeys were rewarded for reaching to an odd-colored target among distractors. Eye movements were unconstrained, and monkeys typically made one or more saccades before initiating a reach. Target selection for reaching and saccades was highly correlated with the hand and eyes landing near the same final stimulus both for correct reaches to the target and for incorrect reaches to a distractor. Incorrect reaches showed a bias in target selection: they were directed to the distractor in the same hemifield as the target more often than to othe...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Song, J.-H., McPeek, R. M. Tags: Articles Source Type: journals

Asymmetric Changes in Cutaneous Reflexes After a Partial Spinal Lesion and Retention Following Spinalization During Locomotion in the CatEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Locomotion involves dynamic interactions between the spinal cord, supraspinal signals, and peripheral sensory inputs. After incomplete spinal cord injury (SCI), interactions are disrupted, and remnant structures must optimize function to maximize locomotion. We investigated if cutaneous reflexes are altered following a unilateral partial spinal lesion and whether changes are retained within spinal circuits after complete spinal transection (i.e., spinalization). Four cats were chronically implanted with recording and stimulating electrodes. Cutaneous reflexes were evoked with cuff electrodes placed around left and right su...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Frigon, A., Barriere, G., Leblond, H., Rossignol, S. Tags: Articles Source Type: journals

Time Course of Activity in Itch-Related Brain Regions: A Combined MEG-fMRI StudyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study is the first to demonstrate part of the time course of itch-related brain processing. Combining methods with high temporal and spatial resolution (e.g., MEG and fMRI) would be useful to investigate the temporal aspect of the brain mechanism of itch. (Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Mochizuki, H., Inui, K., Tanabe, H. C., Akiyama, L. F., Otsuru, N., Yamashiro, K., Sasaki, A., Nakata, H., Sadato, N., Kakigi, R. Tags: Articles Source Type: journals

Long-Lasting Context Dependence Constrains Neural Encoding Models in Rodent Auditory CortexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Acoustic processing requires integration over time. We have used in vivo intracellular recording to measure neuronal integration times in anesthetized rats. Using natural sounds and other stimuli, we found that synaptic inputs to auditory cortical neurons showed a rather long context dependence, up to ≥4 s ( ~ 1 s), even though sound-evoked excitatory and inhibitory conductances per se rarely lasted 100 ms. Thalamic neurons showed only a much faster form of adaptation with a decay constant <100 ms, indicating that the long-lasting form originated from presynaptic mechanisms in the cortex, such as synaptic depression....
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Asari, H., Zador, A. M. Tags: Articles Source Type: journals

Context-Dependent Effects of NMDA Receptors on Precise Timing Information at the Endbulb of Held in the Cochlear NucleusEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Many synapses contain both AMPA receptors (AMPAR) and N-methyl-d-aspartate receptors (NMDAR), but their different roles in synaptic computation are not clear. We address this issue at the auditory nerve fiber synapse (called the endbulb of Held), which is formed on bushy cells of the cochlear nucleus. The endbulb refines and relays precise temporal information to nuclei responsible for sound localization. The endbulb has a number of specializations that aid precise timing, including AMPAR-mediated excitatory postsynaptic currents (EPSCs) with fast kinetics. Voltage-clamp experiments in mouse brain slices revealed that slow...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Pliss, L., Yang, H., Xu-Friedman, M. A. Tags: Articles Source Type: journals

Dependence of the Roll Angular Vestibuloocular Reflex (aVOR) on GravityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Little is known about the dependence of the roll angular vestibuloocular reflex (aVOR) on gravity or its gravity-dependent adaptive properties. To study gravity-dependent characteristics of the roll aVOR, monkeys were oscillated about a naso-occipital axis in darkness while upright or tilted. Roll aVOR gains were largest in the upright position and decreased by 7–15% as animals were tilted from the upright. Thus the unadapted roll aVOR gain has substantial gravitational dependence. Roll gains were also decreased or increased by 0.25 Hz, in- or out-of-phase rotation of the head and the visual surround while animals we...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Yakushin, S. B., Xiang, Y., Cohen, B., Raphan, T. Tags: Articles Source Type: journals

Organization of Hue Selectivity in Macaque V2 Thin StripesEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, the neuronal basis of these hue maps was determined by characterizing the selectivity of neurons for isoluminant hues in multiple penetrations within previously characterized V2 thin stripe hue maps. The results indicate that neurons within the superficial layers of V2 thin stripe hue maps are organized into columns whose aggregated hue selectivity is closely related to the hue selectivity of the optically defined hue maps. These data suggest that thin stripes contain hue maps not simply because of their moderate percentage of hue-selective neurons, but because of the columnar and tangential organization of ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Lim, H., Wang, Y., Xiao, Y., Hu, M., Felleman, D. J. Tags: Articles Source Type: journals

Surround Motion Silences Signals From Same-Direction MotionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The response of motion-sensitive neurons to stimuli presented within their receptive field is often affected by stimulation in the surrounding region. These effects have perceptually relevant consequences that can be measured using behavioral techniques. We used psychophysical reverse correlation to characterize directional selectivity in human observers while they processed a local motion stimulus and studied the effect of adding an additional motion signal in the surrounding region. The surround had no effect on response gain for signals of opposite direction but selectively reduced gain for those of same direction. Surp...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Neri, P., Levi, D. Tags: Articles Source Type: journals

Exploring the Superior Colliculus In VitroEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The superior colliculus plays an important role in the translation of sensory signals that encode the location of objects in space into motor signals that encode vectors of the shifts in gaze direction called saccades. Since the late 1990s, our two laboratories have been applying whole cell patch-clamp techniques to in vitro slice preparations of rodent superior colliculus to analyze the structure and function of its circuitry at the cellular level. This review describes the results of these experiments and discusses their contributions to our understanding of the mechanisms responsible for sensorimotor integration in the ...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Isa, T., Hall, W. C. Tags: Reviews Source Type: journals

Top-Down Control of Saccades as Part of a Generalized Model of Proactive Inhibitory ControlEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Lo and colleagues have recently described a recurrent network model of inhibitory control of saccadic eye movements based on neurophysiological observations in the frontal eye field (FEF) and superior colliculus (SC) of rhesus monkeys. This model emphasizes the proactive, inhibition-based, tonic neuronal activity that prevents the eye from moving in a countermanding paradigm. In this review I discuss the model with respect to existing literature that the authors did not mention, suggesting that proactive inhibitory control extends far beyond saccadic control and provides an interesting framework to interpret several attent...
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Ballanger, B. Tags: Neuro Forum Source Type: journals

Preprint Servers and the Journal of NeurophysiologyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
(Source: Journal of Neurophysiology)
Source: Journal of Neurophysiology - November 4, 2009 Category: Neurology Authors: Linden, D. J. Tags: Editorial Source Type: journals

Recovery of Slow Potentials in AC-Coupled Electrocorticography: Application to Spreading Depolarizations in Rat and Human Cerebral CortexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Cortical spreading depolarizations (spreading depressions and peri-infarct depolarizations) are a pathology intrinsic to acute brain injury, generating large negative extracellular slow potential changes (SPCs) that, lasting on the order of minutes, are studied with DC-coupled recordings in animals. The spreading SPCs of depolarization waves are observed in human cortex with AC-coupled electrocorticography (ECoG), although SPC morphology is distorted by the high-pass filter stage of the amplifiers. Here, we present a signal processing method to reverse these distortions and recover approximate full-band waveforms from AC-c...
Source: Journal of Neurophysiology - October 19, 2009 Category: Neurology Authors: Hartings, J. A., Watanabe, T., Dreier, J. P., Major, S., Vendelbo, L., Fabricius, M. Tags: Innovative Methodology Source Type: journals

Transgenic Silencing of Neurons in the Mammalian Brain by Expression of the Allatostatin Receptor (AlstR)Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The mammalian brain is an enormously complex set of circuits composed of interconnected neuronal cell types. The analysis of central neural circuits will be greatly served by the ability to turn off specific neuronal cell types while recording from others in intact brains. Because drug delivery cannot be restricted to specific cell types, this can only be achieved by putting "silencer" transgenes under the control of neuron-specific promoters. Towards this end we have created a line of transgenic mice putting the Drosophila allatostatin (AL) neuropeptide receptor (AlstR) under the control of the tetO element, thus enabling...
Source: Journal of Neurophysiology - October 19, 2009 Category: Neurology Authors: Wehr, M., Hostick, U., Kyweriga, M., Tan, A., Weible, A. P., Wu, H., Wu, W., Callaway, E. M., Kentros, C. Tags: Innovative Methodology Source Type: journals