UC Irvine

Intracellular recordings were obtained from 161 neurons of the cerebellar cortex of 20 awake cats. Seventeen neurons marked by intracellular pressure injection of horseradish peroxidase were morphologically identified as Purkinje cells. Seven other neurons were recovered with a morphology characteristic of Golgi II cells. In addition to intrinsic action potentials typical of cerebellar and other mammalian cortical recordings, both types of cells revealed a fast spike-like component that was relatively insensitive to injected current and could not be attributed to regenerative Na+ or Ca2+ conductances intrinsic to the penetrated neuron. In Purkinje cells, the fast spike often appeared at the initial portion of the potential configuration normally called the climbing fiber response. In the other class of cells, the fast, current-insensitive spike followed the intrinsic cell discharge. The results demonstrate distinctive patterns of electrical activity in two different types of morphologically identified cerebellar neurons. The fast spikes could reflect electrical coupling between the two types of cells. © 1980.