Linked Life Data

17021182

Source:http://linkedlifedata.com/resource/pubmed/id/17021182

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
2006-10-5
pubmed:abstractText
Postsynaptic alterations have been suggested to account for NMDA receptor (NMDAR)-dependent long-term depression (LTD) and long-term potentiation of synaptic strength, although there is substantial evidence supporting changes in presynaptic release. Direct chemical activation of either NMDA or group I metabotropic glutamate receptor (mGluR1) elicits LTD of similar magnitudes, but it is unknown whether they share common expression mechanisms. Using dual-photon laser-scanning microscopy of FM1-43 [N-(3-triethylammoniumpropyl)-4-(4-(dibutylamino)styryl)pyridinium dibromide] to directly visualize presynaptic vesicular release from the rapidly recycling vesicle pool (RRP) at Schaffer collateral terminals in field CA1 of rat hippocampal slices, we found that a persistent reduction in vesicular release from the RRP is induced by NMDA-LTD but not by mGluR1-LTD. Variance-mean analyses of Schaffer collateral release probability (P(r)) at varying extracellular calcium concentrations confirmed that NMDA-LTD was associated with reduced P(r), whereas mGluR1-LTD was not. Pharmacological isolation of NMDAR-dependent and mGluR-dependent forms of stimulus-evoked LTD revealed that both are composed of a combination of presynaptic and postsynaptic alterations. However, when group I mGluR-dependent LTD was isolated by combining an NMDAR blocker with a group II mGluR antagonist, this form of LTD was purely postsynaptic. The nitric oxide synthase inhibitor N omega-nitro-L-arginine blocked the induction of NMDA-LTD but did not alter mGluR-LTD, consistent with a selective role for nitric oxide as a retrograde messenger mediating NMDA-LTD. These data demonstrate that single synapses can express multiple forms of LTD with different sites of expression, that NMDA-LTD is a combination of presynaptic and postsynaptic alterations, but that group I mGluR-LTD appears to be expressed entirely postsynaptically.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
4
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10270-80
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
NMDA-dependent, but not group I metabotropic glutamate receptor-dependent, long-term depression at Schaffer collateral-CA1 synapses is associated with long-term reduction of release from the rapidly recycling presynaptic vesicle pool.
pubmed:affiliation
Department of Cell Biology and Anatomy, New York Medical College, Valhalla, New York 10595, USA.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural