Hippocampal CA1 pyramidal cells of rats have four voltage-dependent calcium conductances.
In isolated rat hippocampal neurons, we observed 4 voltage- and extracellular Ca2+-dependent conductances; i.e. the T-, N- and L-type Ca2+ currents and tetrodotoxin-sensitive transient Ca2+ current. Intracellular perfusion with F- suppressed irreversibly the L-type Ca2+ current and partially the N-type one. omega-Conotoxin inhibited selectively the L-type Ca2+ current. Amiloride reduced strongly the T-type Ca2+ current without affecting the L-type one. Gd3+, nicardipine, phenytoin and octanol had no specific inhibition on the T-, N- and L-type Ca2+ currents. Thereby, the pharmacological property of mammalian CNS neurons for Ca2+ channel blockers considerably differs from that in the peripheral and cultured cells.
Takahashi
K
K
Department of Neurophysiology, Tohoku University School of Medicine, Sendai, Japan.
Wakamori
M
M
Akaike
N
N
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000502:physiology*; D004553:Electric Conductivity; D005682:Gadolinium / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D007811:Lanthanum / Q000494:pharmacology; D009474:Neurons / Q000502:physiology; D009529:Nicardipine / Q000494:pharmacology; D000442:Octanols / Q000494:pharmacology; D010672:Phenytoin / Q000494:pharmacology; D011712:Pyramidal Tracts / Q000502:physiology; D051381:Rats; D013779:Tetrodotoxin / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D000442:Octanols; D013779:Tetrodotoxin; D010672:Phenytoin; D007811:Lanthanum; D000584:Amiloride; D005682:Gadolinium; D009529:Nicardipine