Anomalous optic nerve fiber convergences in the ipsilateral retinocollicular projection: a comparison of congenitally monocular and neonatally one-eye-removed rats.

Single cell responses to electrical stimuli applied to the optic chiasm and to the lateral geniculate nucleus were studied in expanded projection to the ipsilateral superior colliculus of neonatally enucleated and congenitally monocular rats. In both types of rats latencies to the afferent volleys were longer, and the latency correlation between the optic chiasm and the lateral geniculate responses was lower in the ipsilateral than in the contralateral superior colliculus cells. This was interpreted to suggest abnormal convergence of retinal axons with different conduction velocities in the ipsilateral retinocollicular projection. The deviation of ipsilateral superior colliculus cells from the high-latency correlation of the contralateral cells was more marked in congenitally monocular than in neonatally enucleated rats.