Neuroanatomical substrate for the dorsal light response. II. Effects of kainic acid-induced lesions of the valvula cerebelli on the goldfish dorsal light response.

The dorsal light response (DLR) to the continuously rotating light source was investigated in goldfish that had lesioned the valvula cerebelli. The body inclination was observed and analyzed for every 10 degrees of light rotation. The effects of selective lesions of the medial and lateral valvula cerebelli on the DLR were compared. After the lesion of the medial valvula cerebelli, the fish responded to the rotating light in the similar pattern to that seen preoperatively. However, after the unilateral lesion of the lateral valvula cerebelli, the fish did not respond to light from the side contralateral to the lesion, as if the fish had been unilaterally blindfolded. The lesion induced by kainic acid of the rostral and caudal part of the lateral valvula cerebelli differently influenced on the DLR. The DLR was impaired only after the caudal part of the lateral valvula cerebelli was lesioned by kainic acid. These findings suggest that the lateral valvula cerebelli in goldfish mediate the induction of the visually guided aspects of the DLR.