[Quantitative description of a slowly inactivating barium current through the somatic membrane of mollusk neurons].

The slow-inactivating barium current was recorded under voltage clamp conditions from identified neurons of the snail Helix pomatia. Experimental data were analyzed using the Hodgkin-Huxley equations. The dependence of the steady-state value of the inactivation variable on membrane potential was obtained. Slow-inactivating barium current was found to be proportional to the third power of the activation variable. The time constant of activation is strongly dependent upon the membrane potential.