Intracellular Ca2+-ions inactivate K+-current in bullfrog sympathetic neurons.
Neurons from bullfrog sympathetic ganglia were voltage clamped using a single microelectrode, in a sodium-free, calcium-rich solution containing tetraethylammonium. A brief inward calcium current was followed by a long-lasting inward current. The long-lasting inward current corresponded to a depolarizing afterpotential which followed a calcium spike under the current clamp. It was largely due to the M-channel closure. The present study indicates that massive calcium entry can cause inactivation of potassium conductance in vertebrate neurons.
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D000818:Animals; D002118:Calcium / Q000502:physiology*; D005728:Ganglia, Sympathetic / Q000502:physiology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials; D011188:Potassium / Q000502:physiology*; D011892:Rana catesbeiana
D007473:Ion Channels; D011188:Potassium; D002118:Calcium