Multideterminant role of calcium in hippocampal synaptic plasticity.
Hippocampal CA1 cells possess several varieties of long-lasting synaptic plasticity: two different forms of long-term potentiation (LTP) and at least one form of long-term depression (LTD). All forms of synaptic plasticity are induced by afferent activation, all involve Ca2+ influx, all can be blocked by Ca2+ chelators, and all activate Ca(2+)-dependent mechanisms. The question arises as how different physiological responses can be initiated by activation of the same second messenger. We consider two hypotheses which could account for these phenomena: voltage-dependent differences in cytosolic Ca2+ concentration acting upon Ca2+ substrates of differing Ca2+ affinities and compartmentalization of the Ca2+ and its substrates.
Teyler
T J
TJ
Neurobiology Department, Northeastern Ohio College of Medicine, Rootstown 44272-0095.
Cavus
I
I
Coussens
C
C
DiScenna
P
P
Grover
L
L
Lee
Y P
YP
Little
Z
Z
D000818:Animals; D002118:Calcium / Q000502:physiology*; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D013569:Synapses / Q000187:drug effects / Q000502:physiology*
D002118:Calcium