*  Lirias: The fragile X syndrome protein represses activity-dependent translation through CYFIP1, a new 4E-BP
Strong evidence indicates that regulated mRNA translation in neuronal dendrites underlies synaptic plasticity and brain development. The fragile X mental retardation protein (FMRP) is involved in this process; here, we show that it acts by inhibiting translation initiation. A binding partner of FMRP, CYFIP1/Sra1, directly binds the translation initiation factor eIF4E through a domain that is structurally related to those present in 4E-BP translational inhibitors. Brain cytoplasmic RNA 1 (BC1), another FMRP binding partner, increases the affinity of FMRP for the CYFIP1-eIF4E complex in the brain. Levels of proteins encoded by known FMRP target mRNAs are increased upon reduction of CYFIP1 in neurons. Translational repression is regulated in an activity-dependent manner because BDNF or DHPG stimulation of neurons causes CYFIP1 to dissociate from eIF4E at synapses, thereby resulting in protein synthesis. Thus, the translational repression activity of FMRP in the brain is mediated, at least in ...
  https://lirias.kuleuven.be/handle/123456789/252910
*  The Neuropil of the Periglomerular Region of the Olfactory Bulb | Journal of Cell Science
The periglomerular region of the olfactory bulb, apart from containing the somata and stem dendrites of the cells contributing to the glomeruli, is the sole region of distribution of the periglomerular cell thin dendrites and the short-axon cell dendrites. It is also the major site of termination of all axons to the glomerular layer except the olfactory axons - i.e. tufted cell collaterals, periglomerular cell and short-axon cell axons and centrifugal fibres. Its characteristic neuropil has been studied with the electron microscope to define the cells of origin of the types of neuronal process and their synaptic relationships. Three types of axon terminals have been found: those with spherical, large flattened and small flattened vesicles, which are deduced to derive from tufted cell collaterals or centrifugal fibres, periglomerular cell and short axon-cell axons respectively; those with spherical vesicles are consistently associated with asymmetrical ...
  http://jcs.biologists.org/content/9/2/379
*  Homeless People's Network: (FWD) DENDRITE UPDATE: FREE HOUSING for protest of forced psychiatry |long
DENDRITE UPDATE: human rights in "mental health" system April 14, 1998 -- please copy, re-distribute & post! for more info e-mail: Protest@madnation.org NEWS RELEASE -- IMMEDIATE RELEASE Free housing Friday evening, May 1, is available for 100 more people attending Counterprotest of Forced Psychiatry on Sat. morning, May 2, 1998 Psychiatric Survivor Activists and Allies To Pour in from Throughout USA and Canada for Counterprotest on Saturday, May 2, 1998, in Washington, D.C., Freedom Plaza "EVERYTHING IS FREE... JUST GET TO D.C.!!!" say protesters WASHINGTON, D.C. -- Free housing for up to 100 additional activists is available, courtesy of the Center for Creative Non-Violence (CCNV) on on Friday evening, May 1, 1998, for those attending the next morning's Counterprotest. Counterprotesters are arriving from New England and Alaska, from Vancouver and Florida. They are creating a "Counterprotest" of a major US government public relations event promoting the current "mental health system." "Just get ...
  http://hpn.asu.edu/archives/Apr98/0178.html
*  RAB17 (human)
Biological Process: endocytic recycling; establishment of melanosome localization; filopodium formation; immunoglobulin transcytosis in epithelial cells mediated by polymeric immunoglobulin receptor; melanosome transport; regulation of dendrite development; regulation of endocytosis; regulation of filopodium formation; regulation of synaptogenesis; transcytosis ...
  https://www.phosphosite.org/proteinAction.action?id=4854351
*  A tridimensional view of the organization of actin filaments in the central nervous system by use of fluorescent photooxidation
FIGURE 3. Three-dimensional reconstructions of spines stained with phalloidin-eosin followed by photo-oxidation. (A-D) Three-dimensional serial section reconstructions of dendritic spines F-actin positive from neostriatal tissue. F-actin staining was concentrated in the head of the spines (yellow). No F-actin was concentrated either in the presynaptic terminal (red) or in the the dendritc shaft (green). (E) Computed slices through tomographic volumes of hippocampal CA1. Bundles of actin filaments were seen connecting ER to PSD (arrows). (F) Electron tomographic reconstruction of the dendrite spine head. Spines apparatus (blue and yellow) is connected to the post-synaptic density (magenta) through the F-actin filaments. Scales bars: (A, B) = 1 μm; (C,D) = 0.5 μm.. Intermediate voltage electron microscopy (IVEM) is a not a complicated method for obtaining 3-D information about a unique stained structure, such as phalloidin-stained spines. IVEMs operate at higher accelerating voltages ...
  http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S0327-95452008000100001&lng=pt&nrm=iso&tlng=en
*  Ectopic expression of the GABA(A) receptor alpha6 subunit in hippocampal pyramidal neurons produces extrasynaptic receptors and...
We generated transgenic (Thy1alpha6) mice in which the GABA(A) receptor alpha6 subunit, whose expression is usually confined to granule cells of cerebellum and cochlear nuclei, is ectopically expressed under the control of the pan-neuronal Thy-1.2 promoter. Strong Thy1alpha6 subunit expression occurs, for example, in deep cerebellar nuclei, layer V iscocortical and hippocampal pyramidal cells and dentate granule cells. Ligand binding and protein biochemistry show that most forebrain alpha6 subunits assemble as alpha6betagamma2-type receptors, and some as alpha1alpha6betagamma2 and alpha3alpha6betagamma2 receptors. Electron microscopic immunogold labeling shows that most Thy1-derived alpha6 immunoreactivity is in the extrasynaptic plasma membrane of dendrites and spines in both layer V isocortical and CA1pyramidal cells. Synaptic immunolabeling is rare. Consistent with the alpha6 subunits' extrasynaptic localization, Thy1alpha6 CA1 pyramidal neurons have a five-fold increased tonic GABA(A) ...
  https://www.neuroscience.ox.ac.uk/publications/329299
*  Poster at SfN on dendritic disinhibition and flexible gating | John D. Murray
A disinhibitory circuit has recently been studied across multiple areas in the mouse cortex. The circuit consists of three major types of cortical interneurons that are specialized in their synaptic targets. Specifically, vasoactive intestinal peptide positive (VIP) neurons inhibit somatostatin-positive (SOM) neurons, which in turn inhibit dendrites of pyramidal cells. In this way, VIP neurons disinhibit pyramidal dendrites. In vivo experiments have demonstrated that this disinhibitory circuit is recruited by specific behavioral contexts, such as active sensing or receipt of reinforcement signals. However, the function of this disinhibitory circuit remains unclear. To explore the role of dendritic disinhibition in regulating pyramidal cell activity, we studied simple compartmental neuron models endowed with active dendritic processes such as NMDA spikes. We found that disinhibition can effectively mediate a control pathway that opens the gate for signal propagation. ...
  http://johndmurray.org/2014/11/14/poster-at-sfn-on-dendritic-disinhibition-and-flexible-gating/
*  MTCL1 plays an essential role in maintaining Purkinje neuron axon initial segment | The EMBO Journal
The axon initial segment (AIS) is a specialized domain essential for neuronal function, the formation of which begins with localization of an ankyrin‐G (AnkG) scaffold. However, the mechanism directing and maintaining AnkG localization is largely unknown. In this study, we demonstrate that in vivo knockdown of microtubule cross‐linking factor 1 (MTCL1) in cerebellar Purkinje cells causes loss of axonal polarity coupled with AnkG mislocalization. MTCL1 lacking MT‐stabilizing activity failed to restore these defects, and stable MT bundles spanning the AIS were disorganized in knockdown cells. Interestingly, during early postnatal development, colocalization of MTCL1 with these stable MT bundles was observed prominently in the axon hillock and proximal axon. These results indicate that MTCL1‐mediated formation of stable MT bundles is crucial for maintenance of AnkG localization. We also demonstrate that Mtcl1 gene disruption results in abnormal motor coordination with Purkinje cell ...
  http://d2ni3bh4dzb2ig.cloudfront.net/content/early/2017/03/10/embj.201695630
*  MTCL1 plays an essential role in maintaining Purkinje neuron axon initial segment | The EMBO Journal
The axon initial segment (AIS) is a specialized domain essential for neuronal function, the formation of which begins with localization of an ankyrin‐G (AnkG) scaffold. However, the mechanism directing and maintaining AnkG localization is largely unknown. In this study, we demonstrate that in vivo knockdown of microtubule cross‐linking factor 1 (MTCL1) in cerebellar Purkinje cells causes loss of axonal polarity coupled with AnkG mislocalization. MTCL1 lacking MT‐stabilizing activity failed to restore these defects, and stable MT bundles spanning the AIS were disorganized in knockdown cells. Interestingly, during early postnatal development, colocalization of MTCL1 with these stable MT bundles was observed prominently in the axon hillock and proximal axon. These results indicate that MTCL1‐mediated formation of stable MT bundles is crucial for maintenance of AnkG localization. We also demonstrate that Mtcl1 gene disruption results in abnormal motor coordination with Purkinje cell ...
  http://emboj.embopress.org/content/36/9/1227
*  AMICOR: Camillo Golgi (1843-1926)
A FIRST LOOK: Camillo Golgi's original black-and-white drawing of a dog's olfactory bulb appeared in a paper in the Rivista Sperimentale di Freniatria e Medicina Legalein 1875. Colored plates appeared in reprinted versions distributed by Golgi and in the German translation of his paper. Golgi indicated three layers in his drawing. The superficial layer (A) is composed of nerve fiber bundles made of myelinated axons (black lines), a branching blood vessel (outlined in red), and glial cells (red). The nerve fiber bundles enter spheres of cell bodies called glomeruli in the middle layer (B), which consists of gray matter (nerve cell bodies and dendrites). Large mitral cells lining the middle layer (black) are arranged such that their dendrites reach toward the glomeruli, where they form synapses with the axons extending from the superficial layer. The mitral cell axons (some of which are shown in blue) aim for the inner layer (C) of the olfactory bulb. The inner layer also ...
  http://amicor.blogspot.com/2015/10/camillo-golgi-1843-1926.html
*  C. elegans nervous system
Individual neurons in vertebrates are typically highly branched with a complex morphology of their processes (axons and dendrites). In C. elegans almost all neuronal processes are unbranched and extend in a stereotpical fashion. The example in Figure 3 shows a pair of sensory neurons (ASH) with cell bodies located in head ganglia. The two ASH neurons are chemosensory neurons. A single process, the dendrite, extends from the cell body towards the tip of the nose. A second process, the axon, grows first towards the ventral cord through the amphid commissure. It then turns anteriorly and loops in a halfcircle around the pharynx (not visible) within a large axon bundle - the nerve ring (note: the processes in the ventral cord in the figure belong to a second pair of neurons (PVQ) with cell bodies in the tail). The nerve ring is a horseshoe-shaped axon bundle containing neuronal processes of sensory and interneurons which form connections (synapses) as they run next to each other.. The invariant ...
  http://www.sfu.ca/biology/faculty/hutter/hutterlab/research/Ce_nervous_system.html
*  Cells with dendritic morphology and bright interleukin-1 alpha staining circulate in the blood of patients with rheumatoid...
Freshly isolated peripheral blood mononuclear cells (PBMC) from 10 healthy volunteers, 28 patients with rheumatoid arthritis (RA), eight patients with osteoarthritis, and five patients with ankylosing spondylitis were examined for interleukin-1 alpha (IL-1 alpha) and interleukin-1 beta (IL-1 beta) production using monoclonal antibodies and an indirect immunofluorescent method. In freshly isolated PBMC from healthy controls very few cells were stained for either IL-1 type. All 20 RA patients who were not receiving parenteral gold therapy had PBMC staining for IL-1 alpha. In these patients, up to 7.5% of PBMC showed bright IL-1 alpha staining (range 1.2-7.5%). No IL-1 beta staining was seen. These IL-1 alpha-staining cells had a dendritic morphology and the percentage of cells staining correlated well with levels of C-reactive protein, an index of disease activity in these RA patients. Significantly fewer IL-1 alpha-staining cells were present in the peripheral blood of RA patients receiving gold therapy
  https://www.ndorms.ox.ac.uk/publications/481702
*  Structural basis of the functional development of the retina in the cichlid Tilapia leucosticta (teleostei) | Development
The differentiation of retinal cells has been studied with special reference to the formation of functionally important structures. Three phases could be revealed: from day 3 to day 6 retinal cells in the mostly advanced central part show signs of general cell differentiation (formation of ribosomes, endoplasmic reticulum, mitochondria). In the second phase from day 6 to day 9 characteristic nerve cell structures appear (neurites, dendrites, synapses, receptor outer and inner segments). In the last phase from day 9 to day 12 these special structures attain their final, mature appearance, synapses seem ready for function, dendritic invaginations and synaptic ribbons are formed, twin cones become arranged in mosaic patterns. This developmental order conforms to a gradient running from the ganglion cells to the receptors. Neurites and dendrites appear in the ganglion cells on day 3, in the intermediate neuron layer not before day 4. The horizontal cells are the last ones to ...
  http://dev.biologists.org/content/33/1/243
*  Nerve cells, computer artwork - Stock Image P360/0427 - Science Photo Library
Nerve cells. Computer artwork of nerve cells or neurons. Neurons are responsible for passing information around the central nervous system (CNS) and from the CNS to the rest of the body. Each nerve cell comprises a body surrounded by numerous extensions called dendrites. Dendrites collect information from other nerve cells or from sensory cells. Each neuron also has one process called an axon, which passes information to other nerve cells, or to effector cells such as muscle fibres. - Stock Image P360/0427
  http://www.sciencephoto.com/media/307813/view
*  Synaptic Competition Sculpts the Development of GABAergic Axo-Dendritic but Not Perisomatic Synapses
The neurotransmitter GABA regulates many aspects of inhibitory synapse development. We tested the hypothesis that GABAA receptors (GABAARs) work together with the synaptic adhesion molecule neuroligin 2 (NL2) to regulate synapse formation in different subcellular compartments. We investigated mice (
  http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0056311
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  http://www.shipwreckbeads.com/catalog/Beading-Tools-and-Accessories/Beading-Needles/Short-Sharp-Beading-Needles/orderBy/sku/itemsPerPage/20/page/1/item/11SB109/item/11SB134
*  Short Sharp Beading Needles - Beading Needles - Shipwreck Beads
Shipwreck Beads offers the World's Largest Selection of Beads, in addition to a HUGE selection of beading accessories, jewelry making supplies, and beading books. Over 48,000 different styles and colors of beads. We offer both retail and wholesale quantities of beads.
  http://www.shipwreckbeads.com/catalog/Beading-Tools-and-Accessories/Beading-Needles/Short-Sharp-Beading-Needles/orderBy/sku/itemsPerPage/20/page/1/item/20TN112-B/item/20TN150-B
*  Plus it
The fluorescent dyes, Alexa Fluor 488 and 594 are commonly used to visualize dendritic structures and the localization of synapses, both of which are critical for the spatial and temporal integration of synaptic inputs. However the effect of the dyes on synaptic transmission is not known. Here we investigated whether Alexa dyes alter the properties of synaptic currents mediated by two subtypes of AMPA receptors (AMPARs) at cerebellar stellate cell synapses. In naïve mice, GluA2-lacking AMPAR mediated synaptic currents displayed an inwardly rectifying current-voltage (I-V) relationship due to blockade by cytoplasmic spermine at depolarized potentials. We found that inclusion of 100 µM Alexa dye, but not 10 µM, in the pipette solution led to a gradual increase in the amplitude of EPSCs at +40 mV and a change in the I-V relationship, from inwardly rectifying to more linear. In mice exposed to an acute stress, AMPARs switched to GluA2-containing receptors and 100 µM Alexa 594 did not alter the ...
  http://www.eneuro.org/content/early/2016/05/24/ENEURO.0109-15.2016
*  Most recent papers with the keyword snip | Read by QxMD
Exposure to heavy-ion radiation during cancer treatment or space travel may cause cognitive detriments that have been associated with changes in neuron morphology and plasticity. Observations in mice of reduced neuronal dendritic complexity have revealed a dependence on radiation quality and absorbed dose, suggesting that microscopic energy deposition plays an important role. In this work we used morphological data for mouse dentate granular cell layer (GCL) neurons and a stochastic model of particle track structure and microscopic energy deposition (ED) to develop a predictive model of high-charge and energy (HZE) particle-induced morphological changes to the complex structures of dendritic arbors ...
  https://www.readbyqxmd.com/keyword/98320
*  Metals | Free Full-Text | Comparative Morphological and Crystallographic Analysis of Electrochemically- and Chemically-Produced...
Silver powders chemically synthesized by reduction with hydrazine and those produced by electrolysis from the basic (nitrate) and complex (ammonium) electrolytes were examined by X-ray diffraction (XRD) and scanning electron microscopic (SEM) analysis of the produced particles. Morphologies of the obtained particles were very different at the macro level. The needle-like dendrites, as well as the mixture of irregular and regular crystals, were formed from the nitrate electrolyte, while the highly-branched pine-like dendrites with clearly noticeable spherical grains were formed from the ammonium electrolyte. The agglomerates of spherical grains were formed by reduction with hydrazine. In the particles obtained from the nitrate electrolyte, Ag crystallites were strongly oriented in the (111) plane. Although morphologies of Ag particles were very different at the macro level, the similarity at the micro level was observed between chemically-synthesized particles and those ...
  http://www.mdpi.com/2075-4701/7/5/160
*  Plus it
The effects of long-term monocular visual deprivation (MD) on the structure of the terminal arborizations of individual Y-type geniculocortical axons was studied in the cat's cortical area 18. Physiologically classified axons were filled with HRP by intracellular injection, and the three-dimensional distribution of the axons'terminal arborizations was quantified. Individual boutons observed at the light microscope (LM) level were verified as sites of synaptic contact by correlated light and electron microscopy (EM). Single boutons were serially sectioned and reconstructed for subsequent three- dimensional analysis. The arborizations of 17 Y-axons [6 normal (N), 6 nondeprived (ND), and 5 deprived (D)] were analyzed at the LM level, and 372 boutons (104 N, 129 ND, and 139 D) were fully reconstructed from serial sections for analysis at the EM level. MD leads to an expansion in the size of ND arborizations and a variable reduction in the size of the D arbors, which also have a higher bouton density ...
  http://www.jneurosci.org/content/11/10/3268
*  Plus it
In this study, we demonstrate that the transcription factor Ptf1a is capable of cell autonomously redirecting cortical pyramidal cell identity toward an inhibitory peptidergic fate. Despite a dramatically different intracellular and extracellular milieu, Ptf1a is capable of commandeering the pyramidal cell transcriptome to instruct an inhibitory interneuronal molecular expression pattern and induce the inhibitory neuropeptide nociceptin. These alterations in gene expression resemble the transcriptional signatures of both endogenous Ptf1a-expressing spinal interneurons and endogenous cortical interneurons. In addition, Ptf1a misexpression also induces a transformation of pyramidal cell morphology to a more radial, branched projection pattern, which persists postnatally.. Our transcriptome analysis allowed us to distinguish which genes Ptf1a can induce or suppress cell autonomously. Globally, comparing differentially expressed genes in Ptf1a-misexpressing pyramidal cells with a gene set from ...
  http://www.jneurosci.org/content/35/15/6028
*  Plus it
FMRP has emerged as a central player in the regulation of protein synthesis-dependent synaptic plasticity. However, we know very little about how FMRP expression itself may be regulated as a function of neural activity in vivo, particularly during the time course over which major changes in synaptic reorganization occur. To address this question, we have determined the role of visual experience in regulating FMRP expression in the visual cortex of DR/LE rats. The most striking finding is that experience induces a rapid but transient expression of FMRP in this system. Furthermore, this transient upregulation of FMRP is observed in both dendrites and cell bodies and requires NMDA receptor activation. Our findings suggest that FMRP plays a dynamic role in experience-induced plasticity, especially during the first 15 min of synaptic reorganization.. We used both biochemical and immunohistochemical methods to study experience-dependent FMRP regulation. Immunolocalization revealed that, 15 min ...
  http://www.jneurosci.org/content/24/47/10579
*  New class of molecules may protect brain from stroke, neurodegenerative diseases - Scienmag: Latest Science and Health News
Working in neuronal cell cultures from the cerebral cortex and from the hippocampus and a model of ischemic stroke, the researchers found that elovanoids not only protected neuronal cells and promoted their survival, but helped maintain their integrity and stability. The work is published in Science Advances, available http://advances.sciencemag.org/content/3/9/e1700735 .. 'Our findings represent a breakthrough in the understanding of how the complexity and resiliency of the brain are sustained when confronted with adversities such as stroke, Parkinson's or Alzheimer's and neuroprotection signaling needs to be activated,' says Dr. Bazan. 'A key factor is how neurons communicate among themselves. These novel molecules participate in communicating messages to overall synaptic organization to ensure an accurate flow of information through neuronal circuits. We know how neurons make synaptic connections with other neurons, however these connections have to be malleable to change strength ...
  https://scienmag.com/new-class-of-molecules-may-protect-brain-from-stroke-neurodegenerative-diseases/
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