Effects of diazepam and D-amphetamine on rhythmic pattern of eye movements in goldfish.

The effects of diazepam and D-amphetamine on spontaneous, vestibular- and visually-induced eye movements were studied in the restrained goldfish. These animals showed a stereotyped pattern of spontaneous eye movements that scanned the visual field in the horizontal plane. Fourier analysis of these eye movements revealed a rhythmic pattern of about 5 cycles per minute, whose frequency increased to double and decreased to half following treatment with diazepam and D-amphetamine, respectively. However, the fast and slow components of vestibulo-ocular and optokinetic reflexes, as well as peculiar blink-like movements, remained unchanged at the same drug doses. These results suggest the presence of a central pattern generator for spontaneous eye movements in the goldfish, whose oscillation frequency is pharmacologically modifiable.