The influence of pilocarpine and atropine on pentobarbital-induced nystagmus in the New Zealand white rabbit.

Nystagmus, induced by intravenous pentobarbital in rabbits, increased in frequency and amplitude as a result of intravenous pilocarpine administration. In seven of nine animals anesthetized with pentobarbital but not showing eye movements, pilocarpine injection elicited nystagmus. In all rabbits, nystagmus was terminated by subsequent intravenous administration of atropine, indicating that the parasympathetic nervous system contributes to nystagmus observed in barbiturate treated animals. The results reported here are of value in their implication for an understanding of the physiologic mechanisms which underlie eye movement disorders commonly observed in barbituarate intoxicated individuals.