Linked Life Data

15736233

Source:http://linkedlifedata.com/resource/pubmed/id/15736233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-3-3
pubmed:abstractText
During development, dendritic spines emerge as stubby protrusions from single synapses on dendritic shafts or from retracting filopodia, many of which have more than one synapse. These structures are rarely encountered in the mature brain. Recently, confocal and two-photon microscopy have revealed a proliferation of new filopodia-like protrusions in mature hippocampal slices, especially when synaptic transmission was blocked. It was not known whether these protrusions have synapses nor whether they are accompanied by the other immature spine forms. Here, reconstruction from serial section electron microscopy (ssEM) was used to answer these questions. Acute hippocampal slices from mature male rats, ages 56 and 63 days, were maintained in vitro in control medium or in a nominally calcium-free medium with high magnesium, glutamate receptor antagonists, and sodium and calcium channel blockers. At the end of each 8-hour experiment, all slices were fixed, coded, and processed for ssEM. In agreement with light microscopy, there were more filopodia along dendrites in slices with blocked synaptic transmission. These filopodia were identified by their pointy tips and either the absence of synapses or presence of multiple synapses along them. There was also a proliferation of stubby spines. Filopodia along mature dendrites were typically shorter than developmental filopodia, with outgrowth likely being constrained by reduced extracellular space and compact neuropil, providing numerous candidate presynaptic partners in the vicinity of the mature dendrites. These findings suggest that synaptogenesis and spine formation are readily initiated under conditions of reduced activity in the mature brain.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9967
pubmed:author
pubmed:copyrightInfo
Copyright 2005 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
484
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
183-90
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Synaptogenesis on mature hippocampal dendrites occurs via filopodia and immature spines during blocked synaptic transmission.
pubmed:affiliation
Department of Biology, Boston University, Boston, Massachusetts 02215, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't