Dihydroergotoxine-induced modulation of spontaneous activity of cultured rat Purkinje cells.

We use nerve tissue cultures as a model system for studying the mode of action of centrally acting drugs. Neurons in cerebellar cultures retain a number of organ-specific properties including the formation of complex synaptic networks and characteristic bioelectric activity. Electrical activity may be recorded from Purkinje cells which can be identified by direct visualization. We observed that dihydroergotoxine mesylate (DHET; active substance of Hydergine) modulated the spontaneous activity of cultured neurons. Addition of 10(-8)g/ml DHET to rat cerebellar explants led to a significant regularization of the spontaneous firing of Purkinje cells. Within the 10(-10) - 10(-5)g/ml concentration range used in these experiments, DHET had no detectalbe effect on the average firing rate.