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Topic: Dendritic spine


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In the News (Sun 20 Dec 09)

  
  Development of Dendritic Spines
Dendritic filopodia are formed from the dendrites first and then convert into spines after being innervated by synaptic fibers.
Spines are predominantly found at excitatory synapses where inputs from many areas of the brain arrive.
If each spine is able to receive and store inputs, and there are thousands of spines on each dendrite, then it is understandable that humans can learn and retain facts and ideas throughout their lives as well as synthesize original thoughts.
serendip.brynmawr.edu /bb/neuro/neuro01/web1/Ledoux.html   (969 words)

  
 Dendritic Spines
Dendritic spines are known to change shape, to the extend of appearing and disappearing entirely.
Perhaps dendritic spines contain Arp2/3 complexes forming branching networks whose regulation may not be dependent on the process length.
As spines are stimulated with for example NMDA, calcium flows into the spine (through the NMDA receptor) and this leads to the slowing of actin cycling.
www.bms.ed.ac.uk /research/others/smaciver/Cyto-Topics/dendritic_spines.htm   (1386 words)

  
  Research Areas @ LEMS: 3D shocks for Shape - Results (Dendritic spine)
Dendritic spines are minute protrusions which cover the dendrites of the pyramidal neurons of cerebral cortex.
Therefore, the number and size of dendritic spines are considered indicators of the state of synaptic input to a given neuron.
Imaging the dendritic spines on a given neuron reveals both the individual states of synapses and their collective distribution on that neuron.
www.lems.brown.edu /vision/researchAreas/Shocks3D/Results/DendriticSpine.html   (374 words)

  
  Dendritic Spine Pathology in Infants With Severe Protein-Calorie Malnutrition -- Benítez-Bribiesca et al. 104 ...
in neurons, mainly in the dendritic synaptic apparatus.
To study the dendritic spine density and morphology in dendrites from cortical neurons in infants dying from severe malnutrition.
Short apical dendrites, fewer spines, and dendritic spine abnormalities occur in severe infant malnutrition.
pediatrics.aappublications.org /cgi/content/abstract/104/2/e21   (346 words)

  
 Dark-reared dendritic spines shed light on ocular dominance plasticity
Dendritic spines lie across the synaptic cleft, opposite the presynaptic axon terminals, and contain the receptors for the neurotransmitter glutamate that translate a signal to the postsynaptic cell.
Spines are also electrical compartments due to the higher neck resistance causing voltage-gated ion channels to be activated in one spine but not its neighbors, thereby isolating axonal inputs from one another [10, 11].
B: Spine turnover persists in the adult however [19, 24, 25], and is increased by sensory deprivation, for instance in the barrel cortex after a checker-board pattern of whisker trimming [19].
www.cellscience.com /reviews3/dendritic_spines_ocular_dominance_plasticity.html   (4475 words)

  
 Nature Protocols: The choice of cranial window type for in vivo imaging significantly affects dendritic spine turnover ...
Dendrites and spines in the area of interest should be clearly visualized at this stage.
Transient and persistent dendritic spines in the neocortex in vivo.
Dynamics of both spines and total protrusions (spines and filopodia) were plotted for comparison with previous studies under thinned- and open-skull windows.
www.natureprotocols.com /2007/04/11/the_choice_of_cranial_window_t.php   (2969 words)

  
 Assistant Telethon Scientist
Dendritic spines form the postsynaptic contact sites for the majority of excitatory synapses in the mammalian central nervous system, making them ideally placed to act as integrators of information flow in brain circuit.
Based on their strategic location as bridges between axons and dendrites, spines have long attracted interest as potential mediators of the connective plasticity that is believed to underlie learning and memory.
Therefore the cellular and molecular mechanisms underlying dendritic spines formation and shape regulation are intriguing and fundamental questions that attract the interest of many neuroscientists.
www.telethon.it /dti/researcher.asp?idPersona=13   (480 words)

  
 Scientific Frontline / The Calculating Brain: New Studies Suggest That Neurons Are Built To Perform Simple Arithmetic
These structures are ubiquitous: spines cover most neurons in the brain and are responsible for mediating close to 90 percent of all brain connections.
Overall, they concluded that spines are electrical devices and that their necks keep them electrically isolated from the rest of the spines in the neuron.
Maybe long spines constitute a reservoir of synapses or circuits; and when an animal learns, the necks shorten and activate those synapses.” Perhaps significantly, noted the researchers, human brains have a larger population of long-necked spines than other animals, which might contribute to their enhanced learning ability.
www.sflorg.com /sciencenews/scn112006_02.html   (1389 words)

  
 Dorlands Medical Dictionary
ili´aca poste´rior infe´rior [TA] posterior inferior iliac spine: a blunt bony projection from the posterior border of the ilium, corresponding to the posterior lower extremity of the facies auricularis and the posterior upper extremity of the incisura ischiadica major.
ischia´lis spine of ischium: a strong process of bone projecting backward and medialward from the posterior border of the ischium, on a level with the lower border of the acetabulum and serving to separate the major and minor ischiadic notches.
nasa´lis ante´rior maxil´lae [TA] anterior nasal spine of maxilla: the sharp anterosuperior projection at the anterior extremity of the nasal crest of the maxilla.
www.mercksource.com /pp/us/cns/cns_hl_dorlands.jspzQzpgzEzzSzppdocszSzuszSzcommonzSzdorlandszSzdorlandzSzdmd_s_18zPzhtm   (3063 words)

  
 3DMA-Neuron
Further, the dendrite and spine morphology functionalities have been integrated, so that both the branching morphology as well as the fine scale structure of a neuron can be analyzed when a neuron is imaged at sufficiently high resolution.
The image analysis algorithms (for both the dendritic spine detection and the dendritic branching detection) consist of three general steps: image segmentation, extraction of the medial axis of the neuron phase, and analysis of the medial axis and neuron phase.
Spine volume is determined to be sum of the volume of all voxels contained in the spine.
www.ams.sunysb.edu /~lindquis/3dma/3dma_neuron/3dma_neuron.html   (1903 words)

  
 Neurabin/Protein Phosphatase-1 Complex Regulates Dendritic Spine Morphogenesis and Maturation -- Terry-Lorenzo et al. ...
neuronal filopodia and dendritic spines and the maturation of
Abnormal dendritic spine characteristics in the temporal and visual cortices of patients with fragile-X syndrome: a quantitative examination.
Rao, A., and Craig, A. Signaling between the actin cytoskeleton and the postsynaptic density of dendritic spines.
www.molbiolcell.org /cgi/content/full/16/5/2349   (6944 words)

  
 FEBS Abstract
Formation of a dendritic spine begins with apparition of a filopodia that maturates into a spine displaying neck and head.
We studied the role of Shank and glutamate receptors in dendritic spine formation.
In aspiny cerebellar granular cells, over-expression of Shank induced formation of dendritic spines that co-localized with axon terminals, increased the number of endogenous functional glutamate receptors and increased spontaneous synaptic activity.
www.blackwellpublishing.com /febsabstracts2005/abstract.asp?id=40918   (251 words)

  
 Proteins Anchor Memories in Our Brain : University of Utah News Release : November 21st, 2006
The synapse includes three parts: the end or "axon" of the upstream nerve cell, the microscopic gap between nerve cells, and a mushroom-shaped "dendritic spine," which is part of the downstream nerve cell.
A single nerve cell may have 10,000 dendritic spines, and each spine is part of a synapse.
AMPA receptors can leave the dendritic spine completely, moving from the stalk to other parts of the dendrite that also are outside of the synapse.
www.unews.utah.edu /p/?r=111706-1   (1235 words)

  
 Twitching synapses provide new insight into brain development - MIT News Office
The dendrites of cortical neurons are densely covered with spines that enable single cells to receive input from thousands of others, leading to the changes in dendritic spine shape and density that underlie learning and memory.
Each spine is less than a micron in width, about a hundredth the width of a human hair, and there are trillions of them in the human brain.
Understanding how synapses and spines are altered is central to understanding how connections between brain cells form as the cortex develops, which is key to understanding how the environment shapes brain networks during development.
web.mit.edu /newsoffice/2004/spines.html   (782 words)

  
 International Brain Research Organization   (Site not responding. Last check: )
Novel spines were formed in response to plasticity-producing stimuli in a manner that was selective for the stimulated dendritic segment, and were not found in unstimulated segments of the dendritic tree of the same neuron.
This dual behavior, the formation of spines in association with an active presynaptic terminal and the pruning of a non active synapse, can be considered as the morphological manifestation of the Hebbian rule, where binding of pre- and postsynaptic activity leads to growth of a synapse.
The current ability to produce longer spines or spines with larger heads in a selective population of transfected neurons will undoubtedly contribute to the understanding the functional significance of spine heterogeneity and, through this, to the understanding of the role of spines in synaptic interaction and plasticity.
www.ibro.info /Pub_Main_Display.asp?Main_ID=357   (2313 words)

  
 Dendritic Spine Pathology in Infants With Severe Protein-Calorie Malnutrition -- Benítez-Bribiesca et al. 104 ...
Differences in dendritic spine density between the proximal and distal portion of the apical dendrites in the motor area.
a shortening of the apical dendrite, a significant decrement of
in 1990 postulated that the spine is the smallest neuronal compartment
pediatrics.aappublications.org /cgi/content/full/104/2/e21   (3596 words)

  
 AMPA-receptor activation regulates the diffusion of a membrane marker in parallel with dendritic spine motility in the ...
AMPA-receptor activation regulates the diffusion of a membrane marker in parallel with dendritic spine motility in the mouse hippocampus -- Richards et al.
was significantly retarded relative to the dendritic shaft.
In parallel, we have assessed the motility of dendritic spines,
jp.physoc.org /cgi/content/abstract/558/2/503   (461 words)

  
 Biological Sciences, Open University
This research utilises morphometrical analysis of dendritic spine populations as well as quantification of immediate early gene expression in order to determine the precise localisation of synaptic change in the hippocampus following learning in established paradigms.
Rodríguez J.J., Davies H A., Errington, M.L., Bliss T.V.P., Stewart M.G. (2005) Long-term potentiation in the dentate gyrus is associated with enhanced levels of ARC/ARG3-1 protein expression in dendrites, spines and glia: an ultrastructural study in the rat.
Popov, V.I., Deev, A.A., Klimenko, O.A., Kraev, I.V., Kuz'minykh, S.B., Medvedev, N.I., Patrushev, I.V., Popov, R.V., Rogachevskii, V.V., Khutsian, S.S., Stewart, M.G., Fesenko, E.E. Three-dimensional reconstruction of synapse and dendritic spines in the hippocampus of rats and ground squirrels: new paradigms of the structure and function of a synapse.
www.open.ac.uk /science/biosci/research/mgs/stewart.htm   (1006 words)

  
 Dendritic Spines
The spine is a small protrusion, less than a mm in length, onto which synapses are made.
the spine is the unitary locus of memory formation and storage.
dendrite to the two transients in the spines: the dendrite adjacent to the short
www.weizmann.ac.il /neurobiology/labs/segal/spines.html   (376 words)

  
 3DMA-neuron
It has the capability to determine automatically detailed analysis of dendritic length and characteristics of dendritic spines [7], as well as determining automatically branching morphology of neurons [8, 10], requiring only a limited number of parameters.
We have integrated the dendritic branching and spine detection algorithms to obtain multiscale morphological analysis of pyramidal neurons.
For dendritic spine morphology analysis, the data set was first subdivided into non-overlapping tiles; algorithms to detect spine characteristics were then applied to each tile (see above).
www.ams.sunysb.edu /~cweaver/3dma/3dma.html   (1830 words)

  
 Synaptic plasticity: Dendritic spines shape up - Cell Signaling Update - Signaling Gateway
in the spine compartments relative to concentrations in spines with larger necks.
The volume of the spine head is important for the regulation of synaptic transmission, possibly through variations in expression levels of functional glutamate receptors.
By contrast, the specific structure of the spine neck seems to directly influence synaptic Ca signalling in dendrites, and is therefore a determining factor in the selective induction of synaptic plasticity.
www.signaling-gateway.org /update/updates/200507/nrn1711.html   (390 words)

  
 NIDA - Newsroom - Amphetamine or Cocaine Exposure May Limit Brain Cell Changes That Normally Occur with Life Experiences
The environment contained a variety of stimuli: multiple levels with ramps, bridges, and a climbing chain; tunnels; and toys that were rearranged once a week to encourage continued exploration of the environment.
As in their previous studies, the researchers found that amphetamine increased dendritic branching and spine density in the nucleus accumbens, and decreased spine density in the parietal cortex.
Exposure to the complex environment also increased the dendritic branching and spine density in the nucleus accumbens, and, in contrast to amphetamine, increased dendritic branching and spine density in the parietal cortex as well.
www.drugabuse.gov /Newsroom/03/NR8-25.html   (891 words)

  
 Activity-induced targeting of profilin and stabilization of dendritic spine morphology - Nature Neuroscience
Morphological changes in dendritic spines have been implicated in connective plasticity in brain circuitry, but the underlying pathway leading from synaptic transmission to structural change is unknown.
Using primary neurons expressing GFP-tagged proteins, we found that profilin, a regulator of actin polymerization, is targeted to spine heads when postsynaptic NMDA receptors are activated and that actin-based changes in spine shape are concomitantly blocked.
These results suggest that, in addition to electrophysiological changes, NMDA receptor activation initiates changes in the actin cytoskeleton of dendritic spines that stabilize synaptic structure.
www.nature.com /neuro/journal/v6/n11/abs/nn1135.html   (203 words)

  
 Regional Dendritic and Spine Variation in Human Cerebral Cortex: a Quantitative Golgi Study -- Jacobs et al. 11 (6): ...
Belichenko PV, Dahlström A (1995) Studies of the 3-dimensional architecture of dendritic spines and varicosities in human cortex by confocal laser scanning microscopy and Lucifer Yellow micro- injections.
Elston GN, Rosa MGP, Calford Mbyte (1996) Comparison of dendritic fields of layer III pyramidal neurons in striate and extrastriate visual areas of the marmoset: a Lucifer Yellow intracellular injection study.
Jacobs B, Driscoll L, Schall M (1997) Life-span dendritic and spine changes in areas 10 and 18 of human cortex: a quantitative Golgi Study.
cercor.oxfordjournals.org /cgi/content/full/11/6/558   (7014 words)

  
 Reduced dendritic spine density on cerebral cortical pyramidal neurons in schizophrenia -- Garey et al. 65 (4): 446 -- ...
correlation was not significant for postmortem interval and spine
Assessment of spine density on layer III pyramidal cells in the prefrontal cortex of schizophrenic subjects.
A comparison of dendritic spine number and type on pyramidal neurons of the visual cortex of old adult rats from social or isolated environments.
jnnp.bmjjournals.com /cgi/content/full/65/4/446   (5668 words)

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