EVIDENCE FOR MODIFIABILITY OF PARALLEL FIBER–PURKINJE CELL SYNAPSES

Publisher Summary Lesion experiments have been performed by a number of investigators in the hope that the destruction of the inferior olive might reveal a functional role of olivary neurons in cerebellar functions. During the course of such experiments, it was recognized that the destruction of dorsal cap neurons leads to a loss of the effect of electric stimulation in the flocculus, which normally induces eye movements. It looks as if Purkinje cell inhibition on vestibular neurons is lost after the death of olivary neurons. In fact, in rats whose olivary neurons had been destroyed by intoxication with 3-acetylpyridine, Purkinje cell inhibition on Deiters neurons was seen only rarely. Purkinje cell inhibition, tested with a vestibulospinal reflex, evoked by electric pulse stimulation of a vestibular nerve, and recorded at cervical segments of the spinal cord, diminishes rapidly after the destruction of the inferior olive, reaching a plateau in five hours.