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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
5
|
| pubmed:dateCreated |
1994-2-25
|
| pubmed:abstractText |
1. The possibility of long-lasting modifications of glutamatergic responses after anoxic-aglycemic (AA) episodes was investigated in CA1 hippocampal neurons of adult slices. Bicuculline (10 microM) was continuously bath applied to block GABAA receptor-mediated currents. AA episodes were induced by brief (1.30-3 min) perfusions with a glucose free artificial-cerebro-spinal-fluid (ACSF) saturated with 95% N2-5% CO2. 2. In presence of (0.6 mM) Mg2+ and a low concentration of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 1 microM), the Schaffer collateral field EPSPs consisted of an early AMPA receptor-mediated component and a late N-methyl-D-aspartate (NMDA) receptor-mediated component. The former was blocked by (10 microM) CNQX and the latter by (50) microM D-2-amino-5-phosphonovalerate (D-APV). The AA episode induced a selective long-term potentiation (LTP) of the NMDA receptor-mediated component [+70 +/- 13% (mean +/- SE), P < or = 0.008, n = 9] without affecting significantly the AMPA receptor-mediated component (+2 +/- 4, P < or = 0.86 n = 9). This selective LTP is due to an enhanced efficacy of synaptic transmission and will be referred to as anoxic LTP. 3. In slices perfused with an ACSF containing a physiological concentration of (1.3 mM) Mg2+ and no CNQX, the intracellularly recorded excitatory postsynaptic potential (EPSP) was mixed (AMPA/NMDA) at -65 mV and exclusively mediated by AMPA receptors at -100 mV. At -65 mV, the AA episode induced a persistent potentiation of the EPSP (peak amplitude potentiated by 43 +/- 6%, P < or = 0.008, n = 9, 1 h after return to control ACSF). This potentiated component of the EPSP was fully sensitive to (50 microM) D-APV. The CNQX-sensitive AMPA receptor-mediated component was not affected by the AA episode (-5.7 +/- 6%, P < or = 0.123, n = 9). Furthermore, at -100 mV a large APV-sensitive component appeared after the AA episode (+58 +/- 18% of the peak amplitude, P < or = 0.018, n = 9). Therefore, the AA episode induced a selective LTP of the NMDA receptor-mediated component of the EPSP. 4. A robust LTP (+50.0 +/- 7.5%, P < or = 0.008, n = 12) of the NMDA receptor-mediated intracellular EPSP was also observed when AMPA receptors were fully and continuously blocked by (15 microM) CNQX.(ABSTRACT TRUNCATED AT 400 WORDS)
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Nov
|
| pubmed:issn |
0022-3077
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
70
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| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
2045-55
|
| pubmed:dateRevised |
2006-11-15
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| pubmed:meshHeading |
pubmed-meshheading:8294969-Animals,
pubmed-meshheading:8294969-Cell Hypoxia,
pubmed-meshheading:8294969-Culture Techniques,
pubmed-meshheading:8294969-Hippocampus,
pubmed-meshheading:8294969-Male,
pubmed-meshheading:8294969-Membrane Potentials,
pubmed-meshheading:8294969-Neurons,
pubmed-meshheading:8294969-Rats,
pubmed-meshheading:8294969-Rats, Wistar,
pubmed-meshheading:8294969-Receptors, AMPA,
pubmed-meshheading:8294969-Receptors, N-Methyl-D-Aspartate,
pubmed-meshheading:8294969-Synaptic Transmission
|
| pubmed:year |
1993
|
| pubmed:articleTitle |
A selective LTP of NMDA receptor-mediated currents induced by anoxia in CA1 hippocampal neurons.
|
| pubmed:affiliation |
Institut National de la Santé et de la Recherche Médicale, U-29, Paris, France.
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| pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|