Inactivation of a slow Ca2+ current in CA1 neurones of the adult rat hippocampal slice.
CA1 neurones of the adult rat hippocampal slice preparation were voltage clamped at or near -40 mV membrane potential using a single electrode clamp method. Depolarizing voltage commands from a holding potential of -40 mV elicited voltage-dependent inward Ca2+ currents comprising a fast and a slow component. The latter one was investigated for its susceptibility to inactivation, which was maximally expressed at around 0 mV membrane potential. When extracellular Ca2+ was replaced by Ba2+, inward currents became much larger and were followed by long tail currents. Similar data were observed in neurones injected with the Ca2+ chelator BAPTA. It is suggested that inactivation of the slow Ca2+ current depends at least partly on the levels of intracellular free Ca2+ in hippocampal neurones.
Nistri
A
A
Inserm U29, Paris, France.
Cherubini
E
E
D000818:Animals; D002118:Calcium / Q000502:physiology*; D002614:Chelating Agents; D004533:Egtazic Acid / Q000494:pharmacology / Q000031:analogs & derivatives; D004558:Electric Stimulation; D005260:Female; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials; D051381:Rats; D011919:Rats, Inbred Strains
D002614:Chelating Agents; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium