TY - JOUR
T1 - Integrated regulation of signal coding and plasticity by NMDA receptors at a central synapse
AU - D'Angelo, Egidio
AU - Rossi, Paola
PY - 1998
Y1 - 1998
N2 - The role of NMDA and non-NMDA glutamate receptors in long-term potentiation has been intensely investigated, yet recent evidence on the dynamics of synaptic depolarization suggests that the original view should be extended. NMDA receptor-mediated currents, apart from their Ca2+ permeability, show a marked voltage dependence, consisting of current increase and slowdown during membrane depolarization. During high-frequency synaptic transmission, NMDA current increase and slowdown are primed by non-NMDA receptor-dependent depolarization and proceed regeneratively. Thus, NMDA receptors make a decisive contribution to membrane depolarization and spike-firing. From the data obtained at the messy fiber-granule cell synapse of the cerebellum, we propose that the electrogenic role of NMDA receptors is functional to LTP induction. Moreover, during LTP, both NMDA and non-NMDA receptor currents are potentiated, thus establishing a feed-forward mechanism that ultimately enhances spike firing. Thus, NMDA receptors exert an integrated control on signal coding and plasticity. This mechanism may have important implications for information processing at the cerebellar messy fiber-granule cell relay.
AB - The role of NMDA and non-NMDA glutamate receptors in long-term potentiation has been intensely investigated, yet recent evidence on the dynamics of synaptic depolarization suggests that the original view should be extended. NMDA receptor-mediated currents, apart from their Ca2+ permeability, show a marked voltage dependence, consisting of current increase and slowdown during membrane depolarization. During high-frequency synaptic transmission, NMDA current increase and slowdown are primed by non-NMDA receptor-dependent depolarization and proceed regeneratively. Thus, NMDA receptors make a decisive contribution to membrane depolarization and spike-firing. From the data obtained at the messy fiber-granule cell synapse of the cerebellum, we propose that the electrogenic role of NMDA receptors is functional to LTP induction. Moreover, during LTP, both NMDA and non-NMDA receptor currents are potentiated, thus establishing a feed-forward mechanism that ultimately enhances spike firing. Thus, NMDA receptors exert an integrated control on signal coding and plasticity. This mechanism may have important implications for information processing at the cerebellar messy fiber-granule cell relay.
KW - Cerebellum granule cells
KW - LTP
KW - NMDA receptors
KW - Synaptic transmission
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U2 - 10.1155/NP.1998.8
DO - 10.1155/NP.1998.8
M3 - Article
C2 - 9920678
AN - SCOPUS:0032323359
VL - 6
SP - 8
EP - 16
JO - Neural Plasticity
JF - Neural Plasticity
SN - 2090-5904
IS - 3
ER -