Activity of dendrites of single Purkinje cells and its relationship to so-called inactivation response in rabbit cerebellum.

Abstract

Activity of dendrites and inactivation responses were studied in the cerebellum of rabbits anesthetized with pentobarbital sodium by means of capillary microelectrode. Activity of Purkinje cell dendrites consisted of a sequential discharge of 2 to 4 unitary spikes, and that the sequential discharge occurred in all-or-nothing fashion upon threshold stimulation of the white matter. Number of spikes within a sequential discharge varied in an unpredictable manner. The discharge of this type also appeared spontaneously and was the sole form of spike activity of the dendrites. It was discovered that an inactivation response of the Purkinje cell (a large depolarization of about 15 msec in duration with spike inactivation) consisted of 4 main components of all-or-nothing character, and number of components within an inactivation response varied in an unpredictable manner. The response consisted of spikes generated in the Purkinje cell dendrites.