Opposing effects of acetylcholine on the two classes of voltage-dependent calcium channels in hippocampal neurons.
Acetylcholine (Ach) was tested for its effect on calcium currents in primary cultures of embryonic rat hippocampal neurons. Ach reversibly depressed, in a dose-dependent way, the high voltage activated (HVA) Ca currents. The effect was antagonized by atropine. Our results suggest that a pertussis toxin (PTX)-sensitive GTP binding protein (G-protein) is involved in the signal transduction mechanism between the Ach receptor and the HVA Ca channel. Activating rather than depressive effects of Ach were observed on the low voltage-activated component of Ca currents. This effect was also antagonized by atropine but is not mediated by a PTX-sensitive G-protein.
Toselli
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M
Max-Planck-Institut für Psychiatrie, Abteilung Neurophysiologie, Planegg, Federal Republic of Germany.
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D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004622:Embryo, Mammalian; D019204:GTP-Binding Proteins / Q000502:physiology; D006624:Hippocampus / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D037342:Pertussis Toxin; D051381:Rats; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology; D015398:Signal Transduction; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D015220:Calcium Channels; D011976:Receptors, Muscarinic; D010566:Virulence Factors, Bordetella; D001285:Atropine; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D000109:Acetylcholine