Relationship of aberrant retinotectal projections to visual orienting after neonatal tectal damage in hamster.

The relationship of visual orienting to the extent of physiologically functional aberrant retinotectal connectivity was determined in hamsters subjected to large lesions of their superior colliculi on the day of birth. No relationship was found. The extent of visual field over which visual orienting could be evoked was always markedly smaller than the extent of visual field over which a physiologic evoked response could be found in the neonatally damaged superior colliculus. No evidence was found that aberrant retinal projections to the deep layers of the superior colliculus produced by neonatal damage contribute substantially to visual-orienting behavior.