Abstract
Rotational evoked potentials were studied in the guinea pig under urethane anesthesia. The stimulus events were triangular velocity changes produced by abrupt reversals of acceleration, and horizontal semicircular canals were stimulated. A positive-negative-positive wave was recorded in the vestibular nuclei and the potential was totally abolished after bilateral labyrinthectomy. Single unit recordings revealed that the peak latency of the negative wave is almost coincident with the peak latency of the excitation of type I vestibular nucleus neurons. It is concluded that the recorded potential to the rotational stimuli in this experiment is of vestibular origin.