Journal of Neurophysiology, Vol 43, Issue 1 165-181, Copyright © 1980 by APS
Eye movements evoked by microstimulation of dorsal cap of inferior olive in the rabbit
N. H. Barmack and D. T. Hess
1. Microstimulation was used in an attempt to activate selectively neurons
of the dorsal cap of the inferior olive in unanesthetized rabbits, and the
eye movements evoked by this microstimulation were recorded. 2. Trains of
microstimulation (20--50 microA, 0.1- to 0.2-ms pulses, 10--60 pulses/s,
2--8 s duration) evoked low-velocity conjugate eye movements directed
toward the side of the stimulated olive. These evoked eye movements were
interrupted by resetting eye movements in the opposite direction and could
be evoked only if the rabbit was in darkness. 3. The velocity of the evoked
eye movements increased during a stimulus train and gradually decreased
after the stimulation was terminated. 4. The low-velocity eye movements
appeared to combine with eye movements evoked by vestibular stimulation
without any significant interaction. 5. After transection of the
olivocerebellar pathway or destruction of the contralateral cerebellar
flocculus, dorsal cap microstimulation no longer evoked ipsilaterally
directed eye movements.
