A calcium-activated, nonselective cationic conductance in Aplysia silent neurons.

We have previously reported the activation of a triphasic current response by calcium injection in voltage-clamped, nonbursting neurons of Aplysia californica. Present evidence indicates that the second phase, a delayed inward current that peaks 10-20 seconds after the end of the injection, is a calcium-activated, nonselective cationic conductance. It can be carried by both sodium and calcium, is not sensitive to chloride concentration changes, but is voltage sensitive, decreasing in amplitude with hyperpolarization.