Pharmacological characterization of voltage-dependent calcium currents in rat hippocampal neurons.
The kinetics and pharmacology of voltage-dependent calcium (Ca) currents in primary cultures of hippocampal neurons were studied using the whole cell clamp technique. The low voltage-activated (LVA) Ca current was activated at -50 mV and completely inactivated within 100 ms. This current was insensitive to omega-conotoxin (omega-CgTx) and to the calcium agonist Bay K 8644. The high-voltage-activated (HVA) Ca current was activated at -20 mV and inactivated incompletely during pulses of 200 ms duration. The snail toxin omega-CgTx revealed two pharmacological components of the HVA Ca current, one irreversibly blocked and the other insensitive to the toxin. Bay K 8644 had a clear agonistic action mainly on the omega-CgTx insensitive component of the HVA Ca current.
Istituto di Fisiologia Generale, Universitá di Pavia, Italy.
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Taglietti
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002478:Cells, Cultured; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D010456:Peptides, Cyclic / Q000494:pharmacology*; D051381:Rats; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D010456:Peptides, Cyclic; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D020866:omega-Conotoxin GVIA; D002118:Calcium