Distribution of choline acetyltransferase in the brain stem of the cat

Activities of choline acetyltransferase were detected in various structures of the brain stem of the cat by radiochemical methods on square punches of fresh tissue. High activities were measured in all cranial motor nuclei and in reticular nuclei such as the gigantocellular tegmental nucleus. Low activities were found in sensory nuclei and in the pyramidal tract, trapezoïd body and inferior and superior olive complex. Raphe nuclei, that also contain serotonergic neurons, exhibit relatively high activities of choline acetyltransferase. In spite of some exceptions, the results are in good accordance with those previously obtained by histochemical methods for acetylcholinesterase.