Hypertrophy of immunohistochemically identified cholinergic neurons of the basal nucleus of Meynert following ablation of the contralateral cortex in the rat.

The effects of unilateral damage of the cortex on cholinergic neurons identified by immunohistochemical demonstration of choline acetyltransferase, were examined in the basal nucleus of the rat. Those cells contralateral to the lesion showed significant hypertrophy as compared with cells in the same nucleus in age- and sex-matched control animals. This enlargement was present by 7 days and persisted after 300 days postoperatively, the longest survival time examined. The age of the animal at operation and the extent of the damage may influence the magnitude of the enlargement. Similar changes were seen in the cholinergic cells of the medial septal nucleus after removal of the contralateral hippocampus.