title: A histological atlas of the macaque (Macaca mulatta) substantia nigra in ventricular coordinates.
abstract: An atlas of the macaque substantia nigra was established in ventricular coordinates. Having verified that nigral contours are stable in both Macaca mulatta and Macaca speciosa, the antero-posterior sequence of four subdivisions was described on eight vertico-transverse levels after a comparison between histological and histochemical data. The pars reticulata constitutes the anterior pole containing pale, small cell-bodies scattered among the numerous endings of the striato-pallido-nigral fibres. Anteriorly, the pars compacta forms the dorsal border of the substantia nigra, but more posteriorly, it leaves the dorsal border and develops ventral fringes. Its large cell-bodies, most often pigmented, rich in Nissl bodies and in acetylcholinesterase, are closely spaced among a few axonal fascicles. The pars lateralis contains a low density of cell-bodies and corresponds to the hilum of entrance of the striato-pallido-nigral fibres and gives rise to a nigro-tectal projection. The pars mixta, dorsally located, contains a low density of neurons varying considerably in size. It represents the hilum of exit of nigral axons which project to various targets.
mesh_terms: D000716:Anatomy, Artistic; D000818:Animals; D008251:Macaca; D008253:Macaca mulatta; D008488:Medical Illustration; D013045:Species Specificity; D013238:Stereotaxic Techniques; D013378:Substantia Nigra / Q000033:anatomy & histology*