Fastigial evoked eye movement and brain stem neuronal behavior in the alert monkey.

Single units in the brain stem were recorded in the awake monkey during concomitant adequate vestibular stimulation, eye movement, and electrical stimulation of the fastigial nucleus in areas that produce short-latency horizontal saccades. Forty-eight percent of the recorded brain stem cells were associated with eye movements; 40% respond only to head rotation; and the remainder are unrelated to either. The activity of the majority of the eye movement-related cells was similar for spontaneously and fastigially evoked saccades. The activity of the head rotation and unrelated cells show no consistent relationship to fastigial stimulation.