Cerebellar influence on the evoked potential of the oculomotor nucleus induced by stimulation of the oculomotor nerve branches in the cat.

Cerebellar influence on the oculomotor evoked potential was investigated. Bilateral decerebration was performed in 25 adult cats by thalamocollicular section under chloralose anesthesia. The evoked potential in the oculomotor nucleus by the electrical stimulation of the isolated medial rectus nerve was inhibited by the repeated electrical stimulation of a restricted area of the cerebellar cortex, and increased in amplitude as a rebound phenomenon after cessation of the cerebellar stimulation. The second wave of complex potential which was incidentally evoked in the oculomotor nucleus, depending upon the position of the recording electrode by the inferior oblique nerve stimulation, ivas either inhibited or facilitated by repeated cerebellar stimulation, depending upon the stimulated cerebellar region. These cerebellar effects on the oculomotor evoked potential were most prominent at the area adjacent to the primary fissure in Lobule VI.