Decrease and recovery of choline acetyltransferase activity in medial thalamus and ventral tegmental area after...

Choline acetyltransferase activities were measured in various forebrain regions 3, 7, 14, 21 and 28 days after bilateral lesions of the pedunculopontine nucleus area with ibotenic acid. The decrease was predominant in the ventral tegmental area and medial thalamus (especially at the caudal level). The decrease recovered as rapidly as 21 days after the lesions. It is concluded that the ascending cholinergic pedunculopontine projection is topographically organized within the thalamus and it appears that the effect of the experimental destruction of the projection recovered within a month.