Multideterminant role of calcium in hippocampal synaptic plasticity.
Animals; Calcium/*physiology; Hippocampus/drug effects/*physiology; Humans; Neuronal Plasticity/drug effects/*physiology; Synapses/drug effects/*physiology
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; Cavus I; Coussens C; DiScenna P; Grover L; Lee Y P; Little Z
Hippocampus
1994
1994-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/hipo.450040602" target="_blank" rel="noreferrer noopener">10.1002/hipo.450040602</a>
Metabotropic glutamate receptor antagonist, (R,S)-alpha-methyl-4-carboxyphenyglycine, blocks two distinct forms of long-term potentiation in area CA1 of rat hippocampus.
Animals; Rats; Electric Stimulation; In Vitro Techniques; Electrophysiology; Excitatory Amino Acid Antagonists/*pharmacology; Long-Term Potentiation/*drug effects; Hippocampus/drug effects/*physiology; Benzoates/*pharmacology; Calcium Channels/drug effects/metabolism/physiology; Glycine/*analogs & derivatives/pharmacology; Ion Channel Gating/drug effects; Receptors; Metabotropic Glutamate/*antagonists & inhibitors
The necessity of metabotropic glutamate receptors (mGluRs) in the induction of long-term potentiation (LTP) has recently been questioned. We examined the effect of (R,S)-alpha-methyl-4-caboxyphenylglycine (MCPG), a selective mGluR antagonist, on two independent forms of LTP. One form induced by a 25 Hz/1 s tetanus is solely N-methyl-D-aspartate (NMDA) receptor-dependent. The other form induced by four 200 Hz/0.5 s bursts in the presence of APV is NMDA receptor-independent. In both paradigms the presence of MCPG prevented the induction of LTP by afferent activation.
Little Z; Grover L M; Teyler T J
Neuroscience letters
1995
1995-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).