Post-metamorphic eye migration in Rana and Xenopus

Abstract

CONTRADICTORY results have been obtained with Xenopus laevis and Rana pipiens in experiments directed at evaluating the possible role of visual experience in assuring proper binocular relations in the optic tectum. Gaze, Keating, and colleagues, working with Xenopus, reported that, in certain circumstances, experimental alteration of the contralateral visuotectal projection by eye rotation results in a modification of the ipsilateral projection so as to re-establish appropriate binocular relations^1,2. Jacobson and co-workers, however, working with Rana, reported no change in the ipsilateral projection after experimental rotation of the eye^3–6. Based on the hypothesis that the ability to respond to experimental perturbation of interocular relationships would correlate with the amount of variation in interocular relationships occurring normally, we predicted that Rana might exhibit substantially less post-metamorphic eye migration than Xenopus. We report here results which confirm this prediction.