THE IPSILATERAL RETINOTECTAL PATHWAY IN THE FROG

The pathway from the retina to the ipsilateral optic tectum has been investigated by observing the effects of localized lesions on the electrical responses recorded from the superficial neuropil of the optic tectum in response to visual stimulation of the ipsilateral eye. The ipsilateral projection travels first to the contralateral tectum and then back by an intertectal link to the ipsilateral tectum. Destruction of the intertectal commissure, the posterior commissure and the deep tegmental commissures does not abolish the ipsilateral responses. After lesions of the post‐optic commissural system the ipsilateral tectal responses disappear.