Topographic distribution of choline acetyltransferase activity and muscarinic and nicotinic receptors in Parkinson brains.

Six human control brains and three parkinsonian brains were sectioned coronally and analyzed for their anteroposterior distribution of choline acetyltransferase (ChAT) activity and number of muscarine- ([3H]-QNB) and nicotine- ([3H]-nicotine) like receptors in caudate nucleus, putamen, and hippocampus. In the putamen of the controls, the ChAT activity was doubled from anterior to posterior, whereas the number of muscarinic binding sites was inversely decreased. This was not observed in the parkinsonian cases. A severe reduction in ChAT activity was found in the two cases of Parkinson's disease with the longest duration of the disease. One of these cases also showed a generally increased number of muscarinic binding sites in all three brain regions. The ratio of [3H]-QNB binding/ChAT activity was also markedly increased 10-400 times in the two cases with a long duration of the disease.