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 'Journal of Neurocytology' source. Sat, 10 Oct 2009 19:33:21 +0100 http://www.medworm.com/index.php?rid=482070&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fqj67826tm5080602%2F Abstract??A key event in neurite initiation is the accumulation of microtubule bundles at the neuron periphery. We hypothesized that such bundled microtubules may generate a force at the plasma membrane that facilitates neurite initiation. To test this idea we observed the behavior of microtubule bundles that were induced by the microtubule-associated protein MAP2c. Endogenous MAP2c contributes to neurite initiation in primary neurons, and exogeneous MAP2c is sufficient to induce neurites in Neuro-2a cells. We performed nocodazol washout experiments in primary neurons, Neuro-2a cells and COS-7 cells to investigate the underlying mechanism. During nocodazol washout, small microtubule bundles formed rapidly in the cytoplasm and immediately began to move toward the cell periphery in a unidire... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482070 Tue, 13 Mar 2007 15:24:06 +0100 482070 http://www.medworm.com/index.php?rid=482066&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fg163738v7w977885%2F Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482066 Tue, 13 Mar 2007 15:24:06 +0100 482066 http://www.medworm.com/index.php?rid=482072&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Ff0t0220p6g27r311%2F Abstract??Pyramidal neurons of the hippocampus and cortex have polarized dendritic arbors, but little is known about the cellular mechanisms distinguishing apical and basal dendrites. We used morphometric analysis and time lapse imaging of cultured hippocampal neurons to show that glutamatergic neurons develop progressive dendritic asymmetry in the absence of polarized extrinsic cues. Thus, pyramidal neurons have a cellular program for polarized dendrite growth independent of tissue microenvironment. Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482072 Tue, 13 Mar 2007 15:24:04 +0100 482072 http://www.medworm.com/index.php?rid=482071&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F86644768157t3172%2F Abstract??The receptor tyrosine kinase TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT-4/5), are critically important for growth, survival and activity-dependent synaptic strengthening in the central nervous system. These TrkB-mediated actions occur in a highly cell-type specific manner. Here we report that cerebellar Purkinje cells, which are richly endowed with TrkB receptors, develop a normal morphology intrkB-deficient mice. Thus, in contrast to other types of neurons, Purkinje cells do not need TrkB for dendritic growth and spine formation. Instead, we find a moderate delay in the maturation of GABAergic synapses and, more importantly, an abnormal multiple climbing fiber innervation in Purkinje cells intrkB-deficient mice. Thus, our results demo... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482071 Tue, 13 Mar 2007 15:24:04 +0100 482071 http://www.medworm.com/index.php?rid=482069&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fx37l21n351255041%2F Abstract??Varicosities are ubiquitous neuronal structures that appear as local swellings along neurites of invertebrate and vertebrate neurons. Surprisingly little is known about their cell biology. We use here culturedAplysianeurons and demonstrate that varicosities are motile compartments that contain large clusters of organelles. The content of varicosities propagate along neurites within the plasma membrane ?sleeve?, split and merge, or wobble in place. Confocal imaging, retrospective immunolabeling, electron microscopy and pharmacological perturbations reveal that the motility of the varicosities? organelle content occurs in concert with an actin scaffold and is generated by actomyosin motors. Despite the motility of these organelle clusters within the cytoplasm along the neurites, el... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482069 Tue, 13 Mar 2007 15:24:04 +0100 482069 http://www.medworm.com/index.php?rid=482068&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fy7612442p2036653%2F Abstract??Recently, intense interest has focussed on electrical coupling between interneurones in cortical regions and their contributions towards oscillatory network activity. Despite mounting circumstantial evidence that pyramidal cells are also coupled, the paucity of direct evidence has made this controversial. Dual intracellular recordings from pairs of cortical and hippocampal pyramids demonstrated strong, but sparse coupling. Approximately 70% of CA1 pyramids close to thestratum radiatumborder were coupled to another pyramid, but only to one or two of their very closest neighbours. On average 25% of the steady state and 10% of the peak action potential voltage change in one cell transferred to the other, supporting synchrony and promoting burst firing. The very high incidence of con... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482068 Tue, 13 Mar 2007 15:24:04 +0100 482068 http://www.medworm.com/index.php?rid=482067&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F761j64h322j75625%2F Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482067 Tue, 13 Mar 2007 15:24:04 +0100 482067 http://www.medworm.com/index.php?rid=482065&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F06172h4m42441l81%2F Abstract??Growing evidence suggests that astrocytes are the active partners of neurons in many brain functions. Astrocytic mitochondria are highly motile organelles which regulate the temporal and spatial patterns of Ca2+dynamics, in addition to being a major source of ATP and reactive oxygen species. Previous studies have shown that mitochondria translocate to endoplasmic reticulum during Ca2+release from internal stores, but whether a similar spatial interaction between mitochondria and plasma membrane occurs is not known. Using total internal reflection fluorescence (TIRF) microscopy we show that a fraction of mitochondria became trapped near the plasma membrane of cultured hippocampal astrocytes during exposure to the transmitters glutamate or ATP, resulting in net translocation of the... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482065 Tue, 13 Mar 2007 15:24:04 +0100 482065 http://www.medworm.com/index.php?rid=482064&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fp85636q8874r4452%2F Abstract??Electrical transmission in the mammalian brain is now well established. A new study by Thomson and colleagues elegantly demonstrates coupling between CA1 hippocampal pyramidal cells, which is far more common than previously supposed. Although the history of coupling is extensive, doubt, predjudice, and technical issues long kept it from wide acceptance. Here ?spikelets? or ?fast prepotentials? are found when two cells are coupled and in this situation result from electrical transmission of impulses from one coupled cell to the other. Interesting questions remain as to whether connexin or pannexin gap junctions serve as the molecular substrate of transmission, and the role of electrical transmission in hippocampal physiology is uncertain. Increased coupling could well contribute t... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=482064 Tue, 13 Mar 2007 15:24:04 +0100 482064 http://www.medworm.com/index.php?rid=181221&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fv763n7q213257542%2F Abstract  In the CSN including the spinal cord, NG2 proteoglycan is a marker of oligodendrocyte progenitors. To elucidate the dynamics of the endogenous neural stem (progenitor) cells in adult rats with spinal cord injury (SCI), we examined an immunohistochemical analysis of NG2, GFAP, and 3CB2, a specific marker of radial glia (RG). SD rats were divided into a SCI group (n = 25) and a sham-operated group (n = 5). In the injury group, laminectomy was performed at Th11–12 and contusive compression injury was created by applying a weight of 30 g for 10 min. Rats were sacrificed at 24 h, and 1, 4, 8 and 12 weeks post-injury. Frozen 20-μ m sections of tissue 5 and 10 mm rostral and caudal to the epicenter of injury were prepared. Immunohistochemistry was performed using antibodies ag... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181221 Fri, 11 Aug 2006 07:15:38 +0100 181221 http://www.medworm.com/index.php?rid=181219&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fdw71h102626u56m2%2F Abstract  Immunocytochemical and electron microscopic methods were used to study the GABAergic innervation in adult cat periaqueductal gray matter (PAG). A mouse monoclonal antibody against γ -aminobutyric acid (GABA) was used to visualize the inhibitory neuronal system of PAG. At light microscopy, GABA-immunopositive (GABAIP) neurons formed two longitudinally oriented columns in the dorsolateral and ventrolateral PAG that accounted for 36% of the neuronal population of both PAG columns; their perikaryal cross-sectional area was smaller than that of unlabeled (UNL) neurons found in the same PAG subdivisions. At electron microscopic level, patches of GABA immunoreactivity were readily detected in neuronal cell bodies, proximal and distal dendrites, axons and axon terminals. Approxim... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181219 Fri, 11 Aug 2006 07:15:38 +0100 181219 http://www.medworm.com/index.php?rid=181217&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F57811n5q70j27q35%2F Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 Journal VolumeVolume 34 Journal IssueVolume 34, Number 6 / December, 2005 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181217 Fri, 11 Aug 2006 07:15:38 +0100 181217 http://www.medworm.com/index.php?rid=181222&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fl784856736p6148h%2F Abstract  The present study was carried out to elucidate the distribution of calcium-independent phospholipase A2 (iPLA2) in the normal monkey brain. iPLA2 immunoreactivity was observed in structures derived from the telencephalon, including the cerebral neocortex, amygdala, hippocampus, caudate nucleus, putamen, and nucleus accumbens, whereas structures derived from the diencephalon, including the thalamus, hypothalamus and globus pallidus were lightly labeled. The midbrain, vestibular, trigeminal and inferior olivary nuclei, and the cerebellar cortex were densely labeled. Immunoreactivity was observed on the nuclear envelope of neurons, and dendrites and axon terminals at electron microscopy. Western blot analysis showed higher levels of iPLA2 protein in the cytosolic, than the nuc... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181222 Fri, 11 Aug 2006 07:15:37 +0100 181222 http://www.medworm.com/index.php?rid=181220&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F4g265225129807u8%2F Abstract  In an effort to understand better the neurochemical changes that occur in Parkinson disease, we have examined the expression patterns of the calcium-binding protein parvalbumin in the zona incerta in parkinsonian rats. Sprague-Dawley rats had small volumes of either saline (control) or 6 hydroxydopamine (6OHDA) injected into the medial forebrain bundle, the major tract carrying dopaminergic nigrostriatal axons. After various post-lesion survival periods, ranging from 2 hrs to 84 days, rats were perfused with formaldehyde and their brains processed for routine tyrosine hydroxylase (TH) or parvalbumin immunocytochemistry. In the 3 to 84 days post-lesion cases, there was an overall 50% reduction in the number of parvalbumin+ cells in the zona incerta on the 6OHDA-lesioned sid... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181220 Fri, 11 Aug 2006 07:15:36 +0100 181220 http://www.medworm.com/index.php?rid=181214&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fc266100712r88713%2F Abstract  The involvement of blood microvessels, representing the anatomic site of the blood-brain barrier (BBB), in brain damage induced by prenatal exposure to lipopolysaccharide (LPS) and/or valproic acid (VPA) was studied in four-week-old rats. The immunogold procedure was applied for localization at the ultrastructural level of endogenous albumin and glucose transporter (GLUT-1) in three brain regions: cerebral cortex, cerebellum and hippocampus. Four groups of rats were used: (1) untreated control, (2) prenatally VPA-treated, (3) prenatally LPS-treated, and (4) prenatally LPS- and VPA-treated. The functional state of the BBB was evaluated as follows: (a) by its tightness, i.e., permeability to blood-borne albumin, and (b) by the expression of GLUT-1 in the endothelial cells (... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181214 Fri, 11 Aug 2006 07:15:36 +0100 181214 http://www.medworm.com/index.php?rid=181218&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fk235506j68181j8v%2F Abstract  Transgenic mice expressing mutant (P301L) tau develop paresis, neurofibrillary tangles and neuronal loss in spinal motor neurons beginning at 4 to 6 months of age. Astrocytes and oligodendrocytes acquire filamentous tau inclusions at later ages. Here we report pathology in the spinal white matter of these animals. Progressive white matter pathology, detected as early as 2 months of age, was most marked in lateral and anterior columns, with sparing of posterior columns until late in the disease. Early changes in Luxol fast blue/periodic acid Schiff (LFB/PAS) and toluidine blue stained sections were vacuolation of myelin followed by accumulation of myelin figures within previous axonal tubes and finally influx of PAS-positive macrophages. Myelin debris and vacuoles were fou... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181218 Fri, 11 Aug 2006 07:15:35 +0100 181218 http://www.medworm.com/index.php?rid=181216&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fu1533w610050u644%2F Abstract  The corpus callosum (CC) is the main white matter tract in the brain and is involved in interhemispheric communication. Using the whole-cell voltage-clamp technique, a study was made of K+-currents in primary cultured astrocytes from the CC of newborn rats. These cells were positive to glial fibrillary acidic protein after culturing in Dulbecco’s Modified Eagle Medium (> 95% of cells) or in serum-free neurobasal medium with G5 supplement (> 99% of cells). Astrocytes cultured in either medium displayed similar voltage-activated ion currents. In 81% of astrocytes, the current had a transient component and a sustained component, which were blocked by 4-aminopyridine and tetraethylammonium, respectively; and both had a reversal potential of −66 mV, indicating that they wer... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181216 Fri, 11 Aug 2006 07:15:35 +0100 181216 http://www.medworm.com/index.php?rid=181215&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F382j77842v51780l%2F Abstract  Calcium binding proteins (CBPs) regulate intracellular levels of calcium (Ca2+) ions. CBPs are particularly interesting from a morphological standpoint, because they are differentially expressed in certain sub-populations of cells in the nervous system of various species of vertebrate animals. However, knowledge on the cellular regulation governing such cell-specific CBP expression is still incomplete. In this work on the L7 segment of the cat spinal cord, we analyzed the localization and morphology of neurons expressing the CBPs calbindin-28 KD (CB), parvalbumin (PV), and calretinin (CR), and co-expressing CB and PV, CB and CR, and PV and CR. Single CBP-positive (+) neurons showed specific distributions: (1) CB was present in small neurons localized in laminae I, II, III a... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181215 Fri, 11 Aug 2006 07:15:34 +0100 181215 http://www.medworm.com/index.php?rid=181213&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fb4625012p23021t2%2F In this study, we examined whether the distribution of receptors was still altered in long-term, regenerated muscle fibers from C57Bl/10 mice. The left sternomastoid muscle of adult mice was injected with 60 μl of lidocaine hydrochloride to induce muscle degeneration-regeneration. In some mice, the sternomastoid muscle was denervated at the time of lidocaine injection. After 90 and 150 days, the nicotinic acetylcholine receptors were labeled with rhodamine-α-bungarotoxin for confocal microscopy. At both intervals studied, the receptors were distributed in spots. In denervated-regenerated fibers, the receptors were distributed as regular branches similar to denervated muscles without lidocaine treatment. These findings suggested that nerve-dependent mechanisms were involved in the c... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181213 Fri, 11 Aug 2006 07:15:34 +0100 181213 http://www.medworm.com/index.php?rid=2508667&cid=s_33362_171_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F4g7t70843gv13521%2F Without Abstract Content Type Journal ArticleCategory ErratumDOI 10.1007/BF02456706Authors C. E. RibakR. C. Roberts Journal Journal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 Journal Volume Volume 16 Journal Issue Volume 16, Number 1 / February, 1987 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=2508667 Tue, 01 Aug 2006 17:39:48 +0100 2508667 http://www.medworm.com/index.php?rid=467666&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fu52956u114231471%2F Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 Journal VolumeVolume 16 Journal IssueVolume 16, Number 1 / February, 1987 (Source: Journal of Neurocytology) Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=467666 Tue, 01 Aug 2006 17:39:48 +0100 467666 http://www.medworm.com/index.php?rid=181231&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fb102760247v02564%2F Summary  The cardiac ganglion ofPortunus sanguinolentus exhibits spontaneous rhythmic activity when isolated. The ganglion contains five large and four small intrinsic neurons and is innervated by three pairs of fibres originating in the thoracic ganglia. We have identified the processes of the large neurons in electron micrographs by injecting these cells with two electron-dense markers, horseradish peroxidase (HRP) and Procion Rubine (PR). In addition we have studied the processes of the four smaller neurons by light microscopy serial reconstructions and by electron microscopy of selected regions. Both markers were found only in neuronal processes and not in glial cells nor in the extracellular space, except close to the soma of the injected cell. Content TypeJournal Article... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181231 Tue, 01 Aug 2006 17:39:48 +0100 181231 http://www.medworm.com/index.php?rid=181228&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F382447154520164w%2F Summary  In order to determine whether the structure of the myelin membranes is modified during experimental allergic neuritis (EAN), we have performed X-ray diffraction studies ofin vivo and of isolated sciatic nerves from Lewis rats exposed to different EAN-producing treatments. We have observed a decrease of the intensities in the X-ray reflections without changes in spatial resolution. The level of decrease correlated with the severity of the demyelinating lesions. In comparison to nerves from normal healthy rats the electron density profile of sciatic nerve myelin from animals in acute stages of EAN showed small differences at both cytoplasmic and extracellular spaces of the myelin membrane. Dynamic X-ray diffraction patterns recorded kineticallyin vivo from a nerve injected in... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181228 Tue, 01 Aug 2006 17:39:48 +0100 181228 http://www.medworm.com/index.php?rid=181227&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fkg2p5mj55275l5q4%2F Summary  The population of microglial cells in the subependymal layer of the subcommissural organ is sparse in normal adult rats. The number of microglial cells was substantially increased in this area following intraventricular injection of the serotonin neurotoxin 5,6-dihydroxytryptamine (5,6-DHT). In sections of plastic embedded material, 1 μm thick, the majority of phagocytic cells scattered in the subependymal layer had an appearance similar to that described in classical studies of microglial cells. At the electron microscopic level microglial cells exhibited the characteristic elongate nucleus with peripheral chromatin condensation. The perikaryon was scanty, containing strands of rough endoplasmic reticulum. The abundant organelles in the processes included Golgi complexes... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181227 Tue, 01 Aug 2006 17:39:48 +0100 181227 http://www.medworm.com/index.php?rid=2508668&cid=s_33362_171_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Ft570422823q42402%2F Summary  Onychophorans are ‘living fossils’ frequently purported to have evolved from the same ancestor as the arthropods and annelids. In the CNS ofPeripatus acacioi, beneath an outer acellular neural lamella, glial cells ensheath the cerebral ganglion and the nerve cords. These glial cells are, however, attenuated and rather few in number and, although they interdigitate with one another, they seem to lack intercellular junctions. Exogenous tracers penetrate between them and into the underlying neuropile, suggesting that there is no structural blood-brain barrier. Throughout the nervous tissue, extracellular spaces occur which contain banded collagen fibrils embedded in a matrix material. Thin glial cell processes, characterized by dense filaments, surround these regio... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=2508668 Tue, 01 Aug 2006 17:39:47 +0100 2508668 http://www.medworm.com/index.php?rid=467665&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fh7q08675w443wn86%2F Summary  Following intraocular injection of the dopamine neurotoxin 6-hydroxydopamine (10–50 μg on two successive days in a Ringer vehicle containing ascorbate and pargyline) and an incubation period of 1 to 18 days, degeneration was noted in presumptive amacrine cells in the retina of the turtle,Pseudemys scripta elegans. Injection of vehicle alone produced no effect. Affected perikarya initially showed swollen mitochondria, lysosomes and distended cisternae. At later stages the cells took on a darkened appearance. In contrast, affected amacrine processes in the inner plexiform layer became markedly distended and lost their cytoplasmic contents, resulting in empty, very swollen profiles. No degeneration was noted distal to the affected cell bodies, i.e. the affected cells were n... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=467665 Tue, 01 Aug 2006 17:39:47 +0100 467665 http://www.medworm.com/index.php?rid=181232&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fr51q653355443pv0%2F Summary  One of the uropod closer muscles in the crayfish, the adductor exopodite, is innervated by two large identified motor neurons. They were injected intracellularly with horseradish peroxidase or nickel chloride to reveal the structure and distribution of the input and output synapses using electron microscopy. The development of nickel with rubeanic acid greatly improved the tissue preservation at the ultrastructural level compared with ammonium sulphide. Cell bodies of the motor neurons lying in the ventro-lateral cortex of the ganglion are extensively invaginated by glial cells. Input synapses occur directly upon the primary neurite within the neuropil or upon the major anterior neurite. They are most abundant, however, upon the numerous smaller neurites of the motor neuro... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181232 Tue, 01 Aug 2006 17:39:47 +0100 181232 http://www.medworm.com/index.php?rid=181230&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F98m78730472v5534%2F Summary  When cat visual cortex (area 17) is reacted with an antibody to vasoactive intestinal polypeptide (VIP) a variety of neuronal types is labelled. Many of the labelled neurons are bipolar in form and are most common in layers II and III, although significant numbers of bipolar neurons are also encountered in layer V. Multipolar cells are also labelled. These are most frequent in layer IV and have a variety of shapes. In layer I, the labelled cells are of three varieties, i.e. horizontal bipolar cells, horizontal bitufted cells and multipolar neurons, while in layer VI the few VIP-positive neurons are horizontal bipolar cells. This suggests that all of the VIP-labelled neurons in cat area 17 are non-pyramidal in form, and this has been confirmed by electron microscopy. In ... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181230 Tue, 01 Aug 2006 17:39:47 +0100 181230 http://www.medworm.com/index.php?rid=181229&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fa4625510h4351r67%2F Summary  Specific antibodies were prepared against rat-brain UDP-galactose:ceramide galactosyltransferase (CGalT) and used to study the localization of this enzyme at light and electron microscopic levels. Using an immunocytochemical technique the presence of CGalT was revealed in the cytoplasm and processes of oligodendrocytes and in myelin sheaths of developing and adult rat brain. No immunostaining was detected in neurons or astrocytes. At the ultrastructural level the immunostaining of oligodendrocytes was most intense at the periphery of cytoplasm and probably included plasma membrane. Among the intracellular organelles of oligodendrocytes, specific labelling was occasionally seen in the stacks of Golgi apparatus membranes. In myelin sheaths anti-CGalT staining seems to be res... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181229 Tue, 01 Aug 2006 17:39:47 +0100 181229 http://www.medworm.com/index.php?rid=181225&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Ft570422823q42402%2F Summary  Onychophorans are ‘living fossils’ frequently purported to have evolved from the same ancestor as the arthropods and annelids. In the CNS ofPeripatus acacioi, beneath an outer acellular neural lamella, glial cells ensheath the cerebral ganglion and the nerve cords. These glial cells are, however, attenuated and rather few in number and, although they interdigitate with one another, they seem to lack intercellular junctions. Exogenous tracers penetrate between them and into the underlying neuropile, suggesting that there is no structural blood-brain barrier. Throughout the nervous tissue, extracellular spaces occur which contain banded collagen fibrils embedded in a matrix material. Thin glial cell processes, characterized by dense filaments, surround these regions and f... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181225 Tue, 01 Aug 2006 17:39:47 +0100 181225 http://www.medworm.com/index.php?rid=181224&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2F29vv502121jl1223%2F Summary  Polarity orientations of microtubules in periaxolemmal and internal regions of squid and lobster axons were determined in order to test the hypothesis that regional differences in particle transport are produced by differentially distributed microtubule subclasses. Over 95% of the microtubules in all regions of the axons investigated were oriented with plus ends located distally, pointing away from axonal somata, and there were no significant differences in orientation ratios in periaxolemmal and internal axoplasm. In axonal sheath glial cells of lobsters, microtubules were found to be oriented parallel to axonal microtubules and to have approximately equally mixed polarities. The results for axonal microtubules did not support the possibility of subclasses of axonal micro... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181224 Tue, 01 Aug 2006 17:39:47 +0100 181224 http://www.medworm.com/index.php?rid=181223&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fj4710tp6442p0141%2F Summary  Frog nerve-muscle preparations were soaked and then fixed in solutions roughly isotonic to frog plasma, or in solutions that were markedly hypertonic or hypotonic. The hypertonic solution decreased the cross-sectional area of the muscle fibres but not of the synaptic vesicles. The hypotonic solution increased the cross-sectional area of the muscle fibres but did not produce comparable increases in the areas of the synaptic vesicles. Apparently the vesiclesin situ do not behave as simple osmometers. This fact is significant for theories of exocytosis and for the mechanism of transmitter packaging in the vesicles. Content TypeJournal Article JournalJournal of NeurocytologyOnline ISSN 1573-7381Print ISSN 0300-4864 Journal VolumeVolume 16 Journal IssueVolume 16, ... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181223 Tue, 01 Aug 2006 17:39:47 +0100 181223 http://www.medworm.com/index.php?rid=181226&cid=s_33362_170_f&fid=33362&url=http%3A%2F%2Fwww.springerlink.com%2Fcontent%2Fq63u333366157515%2F Summary  The giant axons and encompassing sheaths from the stellar nerves of the squidsSepioteuthis sepioidea andLoligo forbesi have been analysed by freeze-fracture. The axolemma exhibits many intramembranous particles (IMPs) that fracture onto the cytoplasmic membrane half-leaflet (P-face); the larger IMPs may be aggregated into clusters. Axoplasmic subsurface cisternae are found beneath this membrane. Clustered or aligned arrays of P-face IMPs are also found on the membranes of the Schwann cells that intimately encapsulate the giant axons as well as ‘capitate’ projections of Schwann cells into the axons. When adjacent Schwann cells abut directly against one another, aligned E-face IMPs are found along the fracture plane of the upturning membranes. These E-face alignments of I... Journal of Neurocytology journals http://www.medworm.com/rss/comments.php?id=181226 Tue, 01 Aug 2006 17:39:46 +0100 181226