Histochemical mapping of succinic dehydrogenase and cytochrome oxidase in the pons and mesencephalon of squirrel monkey (Saimiri sciureus).

Abstract

The distribution of succinic dehydrogenase (SDA) and cytochrome oxidase (Cy. O) has been investigated in a series of sections through the pons and mesencephalon of the squirrel monkey brain. The localization of the two enzymes is very similar in the various regions and shows only slight differences. The epiphysis, however, shows moderately strong SDA and very mild Cy. O activity. Particularly strong SDA and Cy. O activity has been observed in the cell bodies of the various cranial nerve nuclei, nucleus colliculi inferioris, colliculi superioris, nuclei griseum pontis, reticularis tegmenti pontis, lemnisci lateralis pars dorsalis, geniculatum laterale and mediale, and pulvinaris. The enzyme content of the neurons and cell bodies is generally stronger compared to the neuropil which often occurs in smooth, loose, compact and reticulated forms. Any special relationship between the neurons and neuropil with regard to their enzyme content has, however, not been observed. The cranial nerves, and fibers of the brachium conjunctivum, corpus callosum, and fornix show very mild enzyme activity except those of the trapezoid complex which show moderate enzyme activity.