Inferior olive lesion induces long-term modifications of cerebellar inhibition on Deiters nuclei.

The frequency of discharge of cerebellar Purkinje cells and lateral vestibular nuclear cells were recorded at different intervals of time after injection of 3-acetylpyridine (3AP), which destroys the inferior olivary nucleus. During the first few days, Purkinje cells showed an increase of simple spike firing, while Deiters cells showed a strong depression of their discharge. Recordings up to 3 months demonstrated, for both groups of cells, a recovery, whose time course is faster for Deiters cells than for Purkinje cells. A reduced inhibitory efficacy of Purkinje cells, as a consequence of climbing fibre deprivation, is suggested.