Ca2+ signaling requirements for long-term depression in the hippocampus.
It has been hypothesized that the direction of synaptic weight change elicited by synaptic activity depends on the magnitude of the activity-dependent rise in intracellular Ca2+ concentration. Several aspects of this hypothesis were examined at the Schaffer collateral CA1 synapse, where both long-term depression (LTD) and long-term potentiation (LTP) can be elicited and are Ca2+ dependent. Brief tetanic stimulation, which normally generated LTP, could induce LTD when Ca2+ entry via NMDA receptors was limited either by moderate concentrations of D-APV or by voltage clamping cells at negative membrane potentials. Repetitive activation of voltage-dependent Ca2+ channels in the absence of afferent stimulation could also elicit an LTD that was Ca2+ dependent and was occluded by prior generation of homosynaptic LTD using prolonged low evidence that the minimal requirements for inducing LTD involve simply a transient influx of Ca2+ into the postsynaptic cell, via either NMDA receptors or voltage-dependent Ca2+ channels.
Cummings
J A
JA
Graduate Program in Neuroscience, University of California, San Francisco 94143-0984, USA.
Mulkey
R M
RM
Nicoll
R A
RA
Malenka
R C
RC
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004594:Electrophysiology; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D013569:Synapses / Q000502:physiology
D002614:Chelating Agents; D016194:Receptors, N-Methyl-D-Aspartate; D004533:Egtazic Acid; D015763:2-Amino-5-phosphonovalerate; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium