Fluoride reversibly blocks HVA calcium current in mammalian thalamic neurones.
The effect of intracellular fluoride ions on voltage-dependent calcium currents was tested during whole-cell voltage-clamp recordings in thalamic neurones acutely dissociated from young adult rats. It is demonstrated that 5-30 mM intracellular fluoride selectively and reversibly suppresses the high voltage-activated, dihydropyridine-sensitive calcium current, without affecting the transient, low voltage-activated calcium current. Intracellular diffusion of a fluoride-free solution restores the blocking effect on the slow inactivating current induced by a transitory fluoride perfusion obtained by filling the patch microelectrode tip with caesium fluoride.
Dipartimento di Neurofisiologia, Istituto Nazionale Neurologico, Milano, Italy.
L
L
Bertollini
G
G
Biella
E
E
Wanke
G
G
Avanzini
M
M
de Curtis
D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000145:classification / Q000187:drug effects* / Q000378:metabolism; D002478:Cells, Cultured; D002586:Cesium / Q000494:pharmacology; D004095:Dihydropyridines / Q000494:pharmacology; D004558:Electric Stimulation; D005459:Fluorides / Q000494:pharmacology*; D015640:Ion Channel Gating; D008564:Membrane Potentials; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013788:Thalamus / Q000166:cytology*
D015220:Calcium Channels; D004095:Dihydropyridines; D002104:Cadmium; D002586:Cesium; C038806:1,4-dihydropyridine; D005459:Fluorides; D002118:Calcium; C027754:cesium fluoride