A quantitative microchemical study of choline acetyltransferase and acetylcholinesterase in the cerebellum of several species

Discrete areas of the cerebella of five species (rat, pigeon, guinea pig, rabbit, and cat) have been examined for their content of choline acetyltransferase activities. The various layers of the cerebellar cortex for all species was shown to have a much lower activity than that of other structures of the nervous system. The choline acetyltransferase activity of the subcerebellar nuclei, however, was found to be greater than any of the cortical strata. Whether this latter observation is related to extrinsic cerebellar afferent fibers, or indicative of an intrinsic cholinergic pathway derived from neurons present in the subcerebellar nuclei needs to be resolved. The quantitative determination of acetylcholinesterase in the various cerebellar layers of the different species was also studied. A comparison of the distribution of acetylcholinesterase and choline acetyltransferase in the five species studied suggests that there is no apparent correlation between the levels of these two enzymes in the various cerebellar strata or nuclei.