Histochemical mapping of succinic dehydrogenase and cytochrome oxidase in the spinal cord, medulla oblongata and cerebellum of squirrel monkey (Saimiri sciureus).

Abstract

The distribution of succinic dehydrogenase (SDA) and cytochrome oxidase (Cy. O) in serial sections of the cervical region of the spinal cord and the medulla oblongata, arranged caudo-cranially, has been described. The motor cranial nerve nuclei exhibit strong SDA and Cy. O activity in the neurons and neuropil. The nuclei gracilis, cuneatus, olivaris inferior, cochlearis and vestibularis likewise show strong enzyme activity. Nucleus intercalatus and nucleus tractus solitarius, however, show weak and moderate enzyme activity respectively. The lateral part of formatio reticularis myelencephali shows less SDA and Cy. O compared to the medial part, which shows some accumulation of these enzymes in the neuropil. The neuropil of the molecular layer of cerebellar cortex and the perikarya and dendrites of the Purkinje cells show strong SDA and Cy. O activity. The granular layer exhibits stronger SDA and Cy. O in the synaptic glomeruli. The cerebellar nuclei possess stronger enzyme activity in the neurons and dendritic branches, compared to mild activity in the neuropil.