Effect of firing rate on the calcium permeability in adult neurons during spontaneous action potentials.
Calcium channels in neurons mediate a wide variety of essential functions. In addition to contributing to action potential shape, they furnish a substrate that acts as an intracellular second messenger. This study shows that the shape of the neuronal action potential has characteristics that promote long openings of L-type (high threshold) calcium channels. We also present evidence that a change in the firing rate of isolated neurons modulates gating of single calcium channels. This mechanism could be important in modulating neuron excitability and providing a rise in intracellular Ca, when needed.
Mazzanti
M
M
Dipartimento di Fisiologia e Biochimica Generali, Universitá Statale di Milano, Italy.
Galli
A
A
Ferroni
A
A
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004594:Electrophysiology / Q000379:methods; D005727:Ganglia, Spinal / Q000502:physiology*; D015640:Ion Channel Gating / Q000187:drug effects; D007700:Kinetics; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D013997:Time Factors
D015220:Calcium Channels; D013757:Tetraethylammonium Compounds; D019789:Tetraethylammonium; D002118:Calcium