Calcium-dependent inward currents in voltage-clamped guinea-pig olfactory cortex neurones.
Guinea-pig olfactory cortex neurones in vitro (23 degrees C--25 degrees C) were voltage clamped by means of a single microelectrode sample-and-hold technique. In most Cs+-loaded neurones (in the presence of tetrodotoxin), membrane depolarization beyond -60 mV elicited inward currents, which had rapid activation kinetics. The steady-state current-voltage relationship was N-shaped with a region of negative slope conductance between - 50 mV and - 20 mV. The rate of inactivation varied according to the holding potential and the command potential. The inward currents were maintained when external Ca2+ was replaced by Ba2+, and were blocked by Cd2+, suggesting that Ca2+ was the principal charge carrier. The results demonstrate the existence of calcium current in olfactory cortex neurones.
Constanti
A
A
Galvan
M
M
Franz
P
P
Sim
J A
JA
D000818:Animals; D001464:Barium / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002490:Central Nervous System / Q000378:metabolism*; D002540:Cerebral Cortex / Q000166:cytology / Q000378:metabolism*; D002586:Cesium / Q000494:pharmacology; D004594:Electrophysiology; D006168:Guinea Pigs; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D009833:Olfactory Pathways / Q000166:cytology / Q000378:metabolism*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology
D007473:Ion Channels; D013757:Tetraethylammonium Compounds; D002104:Cadmium; D002586:Cesium; D001464:Barium; D019789:Tetraethylammonium; D002118:Calcium