1979 年 38 巻 2 号 p. 190-195
To investigate the neural mechanism of inversion of optokinetic nystagmus we carried out a series of experiments in which normal rabbits and those given repeated electric stimulation of the hippocampus were given a small amount of adrenaline (0.005mg kg) intravenously and resulting changes in optokinetic nystagmus were measured before and 30 minutes after the injection.
The results obtained were as follows :
(1) In normal rabbits there was little evidence of inversion of optokinetic nystagmus.
(2) In rabbits with repeated electric stimulation of the hippocampus inverted optokinetic nystagmus appeared in one third of the number animals examined. Furthermore, the inverted nystagmus thus induced was similar to that induced by electric stimulation of the hippocampus. From these findings we conclude that the neural mechanism of inversion of optokinetic nystagmus is closely correlated with excitation of adrenergic receptors in the central nervous system, particularly those involved in the neural circuits connecting the hippocampus to the oculomotor system.