Accessory oculomotor nuclei of man. 1. The nucleus of Darkschewitsch: a Nissl and Golgi study.

A morphoquantitative study was carried out to provide detailed information regarding the cytoarchitecture and neuronal morphology of the nucleus of Darkschewitsch (ND) of man. The neuronal population showed heterogeneity of shape and size of the nerve cell bodies. Small and medium-sized neurons appeared scattered in a wide neuropil. In the Golgi material, two types of neurons were identified: multipolar and fusiform cells. Multipolar cells, which were the most numerous (77%), had 3-5 dendrites giving off primary bifurcations at a short distance from the nerve cell body. Sometimes dendrites and axons were seen to spread outside the ND. The fusiform cells had 1-2 dendrites emerging from the opposite poles of the elongated nerve cell bodies. The dendrites tended to run unbranched for long distances in the section plane before dichotomizing. The dendrites and axons of the fusiform cells always lay inside the ND. The cytoarchitectural features of the ND corresponded to the characters of the reticular formation so that the ND of man could be considered to be a typical reticular nucleus inside the central gray matter. The prevailing presence of multipolar neurons whose processes often spread outside the ND could suggest that the ND is a mainly projective nucleus.