The morphological effects of infant- and adult-onset monocular paralysis on cells in the cat lateral geniculate nucleus

This experiment has investigated the morphological effects of infant- and adult-onset monocular paralysis on cells in the cat lateral geniculate nucleus (LGN). For comparison, normal adult cats were also studied. These conditions permitted an assessment of the importance of age of onset in the response of the LGN to monocular paralysis. In the cats monocularly paralyzed as adults, cells were found to be smaller throughout much of the binocular segment of the laminae innervated by the paralyzed eye. This pattern of results was comparable to that seen after infant-onset monocular visual deprivation. The effects of rearing cats with monocular deprivation, however, had been attributed to a putatively developmental mechanism. To the extent that the pattern of effects defines the causal mechanism, one must conclude that the mechanism posited to account for the consequences of infant-onset monocular deprivation is not simply a developmental process