Combined spikes induced by Ca and Na currents in cultured cerebellar neurons from the chick embryo

Evoked spikes in explanted cerebellar neurons cultured for 17-25 days, presumably including Purkinje cells, were not completely blocked by 10(-5) g/ml TTX. The TTX-resistant components of the spike were suppressed by Co2+ or Mn2+. It is suggested that combined Ca and Na components are involved in spike generation mechanisms in cultured neurons from the chick cerebellum and that they may be related to the maturation process of excitable membranes of cell soma.