Selective induction of LTP and LTD by postsynaptic [Ca2+]i elevation.
Long-term potentiation (LTP) and long-term depression (LTD), two prominent forms of synaptic plasticity at glutamatergic afferents to CA1 hippocampal pyramidal cells, are both triggered by the elevation of postsynaptic intracellular calcium concentration ([Ca2+]i). To understand how one signaling molecule can be responsible for triggering two opposing forms of synaptic modulation, different postsynaptic [Ca2+]i elevation patterns were generated by a new caged calcium compound nitrophenyl-ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid in CA1 pyramidal cells. We found that specific patterns of [Ca2+]i elevation selectively activate LTP or LTD. In particular, only LTP was triggered by a brief increase of [Ca2+]i with relatively high magnitude, which mimics the [Ca2+]i rise during electrical stimulation typically used to induce LTP. In contrast, a prolonged modest rise of [Ca2+]i reliably induced LTD. An important implication of the results is that both the amplitude and the duration of an intracellular chemical signal can carry significant biological information.
Yang
S N
SN
Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA.
Tang
Y G
YG
Zucker
R S
RS
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects / Q000502:physiology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D066298:In Vitro Techniques; D007424:Intracellular Fluid / Q000378:metabolism; D017774:Long-Term Potentiation / Q000502:physiology*; D009473:Neuronal Plasticity; D018408:Patch-Clamp Techniques; D010782:Photolysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013569:Synapses / Q000378:metabolism / Q000502:physiology*
D002614:Chelating Agents; C085112:2-nitrophenyl-EGTA; D004533:Egtazic Acid; D002118:Calcium