[Modulation of the endogenous activity of the snail bursting neuron]

It is found that remarkable depolarization of the bursting neuron membrane may occur periodically with a frequency of about several minutes. The clamp potential method leads to detecting slow depolarizing currents. It is shown that the frequency is independent of the holding potential. The equilibrium potential of depolarizing current is about +45 mV. During the development of slow depolarizing current the negative conductance region arises in the steady-state voltage-current curve of the membrane. It is suggested that the slow depolarizing currents observed are related to the existence of secretorial transfer in the snail nervous system.