CHOLINE ACETYLTRANSFERASE CONTENT IN DISCRETE REGIONS OF THE RAT BRAIN STEM

Abstract

—Choline acetyltransferase (ChAc) content of 50 separate rat brain stem nuclei and cerebellum removed by microdissection was determined using a sensitive radiometric assay. The distribution of ChAc activity is uneven, with extremely high levels in the cranial motor nuclei and the nucleus salivatorius. Low ChAc concentrations were observed in the cranial sensory nuclei, the nuclei of the reticular formation, the raphe nuclei and the nuclei of the acoustic system. The lowest ChAc levels were measured in the cerebellum. Comparison of the distribution of ChAc with histochemical localization of acetylcholinesterase revealed generally good agreement, and notable exceptions are discussed.