Effects of extracellular potassium concentration and postsynaptic membrane potential on calcium-induced potentiation in area CA1 of rat hippocampus.

Title

Effects of extracellular potassium concentration and postsynaptic membrane potential on calcium-induced potentiation in area CA1 of rat hippocampus.

Creator

Grover L M; Teyler T J

Publisher

Brain research

Date

1990
1990-01

Description

Long-lasting potentiation can be induced in area CA1 of hippocampus by a relatively brief (7-10 min) exposure to a higher (4.0 mM) than normal (2.0 mM) extracellular calcium concentration. We have found that long-lasting calcium-induced potentiation is dependent on extracellular potassium concentration. Slices exposed to high extracellular calcium in the presence of normal extracellular potassium (3.35 mM) showed a transient facilitation. Long-lasting potentiation was induced by exposure to high calcium only in slices also exposed to higher than normal extracellular potassium (6.25 mM). In intracellular experiments we found that injection of depolarizing current into postsynaptic neurons could substitute for high extracellular potassium. These results suggest that calcium-induced potentiation involves a postsynaptic, voltage-dependent mechanism. A similar conclusion has been reached for tetanus-induced potentiation. We also found that calcium-induced potentiation, like tetanus-induced potentiation, is not accompanied by an increase in postsynaptic input resistance.

Subject

Animals; Rats; Action Potentials/drug effects; Membrane Potentials/drug effects; Potassium/*pharmacology; Hippocampus/drug effects/*physiology; Neuronal Plasticity/*drug effects; Calcium/*pharmacology

Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

Pages

53–61

Issue

1

Volume

506

Citation

Grover L M; Teyler T J, “Effects of extracellular potassium concentration and postsynaptic membrane potential on calcium-induced potentiation in area CA1 of rat hippocampus.,” NEOMED Bibliography Database, accessed April 23, 2021, https://neomed.omeka.net/items/show/5450.

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