Possible regulation of the cytosolic-free calcium concentration by Na+ spikes in immature cerebellar Purkinje cells.
Isolated immature cerebellar Purkinje cell bodies often exhibit the spontaneous fluctuations of a cytosolic free Ca concentration ([ Ca]in), which was measured by fura-2 microfluorimetry. In silent cells, however, the increase of [Ca]in could be triggered by pharmacological depolarizations (adding veratridine or tetraethylammonium). In any case, these [Ca]in changes were sensitive to voltage-dependent channel blockers (tetrodotoxin and Ca channel blockers) and to an inhibitory transmitter (GABA). The results suggest that the spontaneous activation of voltage-dependent Na+ and Ca2+ channels might be involved in the increase of [Ca]in.
Sorimachi
M
M
Department of Physiology, Kagoshima University School of Medicine, Japan.
Morita
Y
Y
Nakamura
H
H
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001030:Apamin / Q000494:pharmacology; D002118:Calcium / Q000032:analysis* / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology; D003600:Cytosol / Q000502:physiology; D011689:Purkinje Cells / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000494:pharmacology*; D015222:Sodium Channels / Q000187:drug effects / Q000502:physiology; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology
D015220:Calcium Channels; D015222:Sodium Channels; D013757:Tetraethylammonium Compounds; D001030:Apamin; D013779:Tetrodotoxin; D019789:Tetraethylammonium; D014701:Veratridine; D012964:Sodium; D002118:Calcium