Linked Life Data

2769375

Source:http://linkedlifedata.com/resource/pubmed/id/2769375

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
1989-9-22
pubmed:abstractText
Serial electron microscopy and 3-D reconstructions of dendritic spines from hippocampal area CA 1 dendrites were obtained to evaluate 2 questions about relationships between spine geometry and synaptic efficacy. First, under what biophysical conditions are the spine necks likely to reduce the magnitude of charge transferred from the synapses on the spine heads to the recipient dendrite? Simulation software provided by Charles Wilson (1984) was used to determine that if synaptic conductance is 1 nS or less, only 1% of the hippocampal spine necks are sufficiently thin and long to reduce charge transfer by more than 10%. If synaptic conductance approaches 5 nS, however, 33% of the hippocampal spine necks are sufficiently thin and long to reduce charge transfer by more than 10%. Second, is spine geometry associated with other anatomical indicators of synaptic efficacy, including the area of the postsynaptic density and the number of vesicles in the presynaptic axon? Reconstructed spines were graphically edited into head and neck compartments, and their dimensions were measured, the areas of the postsynaptic densities (PSD) were measured, and all of the vesicles in the presynaptic axonal varicosities were counted. The dimensions of the spine head were well correlated with the area of PSD and the number of vesicles in the presynaptic axonal varicosity. Spine neck diameter and length were not correlated with PSD area, head volume, or the number of vesicles. These results suggest that the dimensions of the spine head, but not the spine neck, reflect differences in synaptic efficacy. We suggest that the constricted necks of hippocampal dendritic spines might reduce diffusion of activated molecules to neighboring synapses, thereby attributing specificity to activated or potentiated synapses.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0270-6474
pubmed:author
pubmed:issnType
Print
pubmed:volume
9
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2982-97
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Dendritic spines of CA 1 pyramidal cells in the rat hippocampus: serial electron microscopy with reference to their biophysical characteristics.
pubmed:affiliation
Department of Neurology, Children's Hospital, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't