Quantitative studies of transneuronal atrophy in the dorsal lateral geniculate nucleus of cats and kittens

The transneuronal cell atrophy that occurs in the dorsal lateral geniculate nucleus after removal of one eye is more rapid in young than in adult cats. The change in the rate of the atrophic change continues well beyond the time at which geniculate cell growth has stopped. In a three and a half month old kitten transneuronal cell shrinkage is clearly evident within three days on the side contralateral to an enucleation, but it does not appear clearly on the ipsilateral side until the twelfth post‐operative day. On both sides of the brain there is some apparent recovery and then a later, slower cell shrinkage. In a seven month old cat the cell changes are slower, and the two stages of the atrophy are less clearly distinguishable. In the three and a half month kittens there is no significant differences between the atrophy that occurs in the binocular and the monocular parts of the nucleus and it is concluded that a binocular, or translaminar competition plays no part in producing the atrophic changes in these kittens. However, in a seven day old kitten removal of one eye appears to produce more severe atrophy in the binocular than in the monocular parts of the nucleus. Thus, a binocular competition, similar to that seen after a lid suture in seven day old kittens, may play a part in the transneuronal atrophy in these very young animals but not in older kittens.