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Titolo:
NOVEL EXPRESSION MECHANISM FOR SYNAPTIC POTENTIATION - ALIGNMENT OF PRESYNAPTIC RELEASE SITE AND POSTSYNAPTIC RECEPTOR
Autore:
XIE XP; LIAW JS; BAUDRY M; BERGER TW;
Indirizzi:
UNIV SO CALIF,DEPT BIOMED ENGN LOS ANGELES CA 90089 UNIV SO CALIF,DEPT BIOL SCI LOS ANGELES CA 90089 UNIV SO CALIF,PROGRAM NEUROSCI LOS ANGELES CA 90089
Titolo Testata:
Proceedings of the National Academy of Sciences of the United Statesof America
fascicolo: 13, volume: 94, anno: 1997,
pagine: 6983 - 6988
SICI:
0027-8424(1997)94:13<6983:NEMFSP>2.0.ZU;2-L
Fonte:
ISI
Lingua:
ENG
Soggetto:
LONG-TERM POTENTIATION; HIPPOCAMPAL PYRAMIDAL CELLS; NMDA RECEPTOR; CA1 REGION; LTP; QUISQUALATE; RESPONSES; SYNAPSES; CHANNELS; NEURONS;
Keywords:
LONG-TERM POTENTIATION; DENTATE GYRUS; LPHA-AMINO-3-HYDROXY-5-METHYLISOXAZOLE-4-PROPIONIC ACID RECEPTOR; N-METHYL-D-ASPARTIC ACID RECEPTOR; SYNAPTIC MODEL;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
45
Recensione:
Indirizzi per estratti:
Citazione:
X.P. Xie et al., "NOVEL EXPRESSION MECHANISM FOR SYNAPTIC POTENTIATION - ALIGNMENT OF PRESYNAPTIC RELEASE SITE AND POSTSYNAPTIC RECEPTOR", Proceedings of the National Academy of Sciences of the United Statesof America, 94(13), 1997, pp. 6983-6988

Abstract

A combination of experimental and modeling approaches was used to study cellular-molecular mechanisms underlying the expression of short-term potentiation (STP) and long-term potentiation (LTP) of glutamatergic synaptic transmission in the hippocampal slice, Electrophysiologicalrecordings from dentate granule cells revealed that high-frequency stimulation of perforant path afferents induced a robust STP and LTP of both lpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) and N-methyl-D-aspartic acid (NMDA) receptor-mediated synaptic responses, However, the decay time constant for STP of the AMPA receptor-mediated excitatory postsynaptic potential was approximately 6 min, whereas the decay time constant for STP of the NMDA receptor-mediated excitatory postsynaptic potential was only 1 min, In addition, focal application of agonists during the expression of STP revealed that the magnitude of conductance change elicited by NMDA application was significantlyenhanced, whereas the magnitude of conductance change elicited by application of AMPA remained constant, These findings are most consistentwith a postsynaptic mechanism of STP and LTP, Different putative mechanisms were evaluated formally using a computational model that included diffusion of glutamate within the synaptic cleft, different kineticproperties of AMPA and NMDA receptor/channels, and geometric relations between presynaptic release sites and postsynaptic receptor/channels. Simulation results revealed that the only hypothesis consistent withexperimental data is that STP and LTP reflect a relocation of AMPA receptor/channels in the postsynaptic membrane such that they become more closely ''aligned'' with presynaptic release sites, The same mechanism cannot account for STP or LTP of NMDA receptor-mediated responses; instead, potentiation of the NMDA receptor subtype is most consistent with an increase in receptor sensitivity or number.

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Documento generato il 20/01/21 alle ore 12:48:52