SLOW AND SACCADIC EYE MOVEMENTS EVOKED BY MICROSTIMULATION IN THE
SUPPLEMENTARY EYE FIELD OF CEBUS MONKEY.
Tian, Jun-Ru and James C. Lynch.
Departments of Anatomy, Ophthalmology and Neurology, University of
Mississippi Medical Center, Jackson, Mississippi 39216-4505.
APStracts 2:0238N, 1995.
SUMMARY AND CONCLUSIONS
Intracortical microstimulation was used to map the supplementary eye field
(SEF) in eight hemispheres of five Cebus apella monkeys. Monkeys were
immobilized during experiments with Telazol, a dissociative anesthetic agent
which was demonstrated to have no significant effect on microstimulation-
induced eye movement parameters compared to similar experiments in alert,
behaviorally trained monkeys. The functional subregions were defined using
lowthreshold current ( < 50 _a). Electrically elicited eye movements were
video taped and quantified. Both slow and saccadic eye movements were reliably
evoked at low threshold by microstimulation in each of eight hemispheres
studied. The two types of eye movements were clearly distinguished by their
significantly different duration and velocity (P < 0.0001) and their different
responses to long stimulus trains. The results strongly support the proposal
that the SEF produces not only saccadic eye movements as previously reported
but also slow (pursuit) eye movements.
Received 11 April 1995; accepted in final form 8 August 1995.
APS Manuscript Number J241-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.