The midbrain dopaminergic cell groups in the baboon papio ursinus

• Published in: Brain research bulletin Vol. 47; no. 6; pp. 611 - 623
• Main Authors: McRitchie, D.A, Cartwright, H, Pond, S.M, van der Schyf, C.J, Castagnoli, N, van der Nest, D.G, Halliday, G.M
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.12.1998; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Calcium binding proteins; Calcium-Binding Proteins - physiology; Cell Size - physiology; Central nervous system; Central neurotransmission. Neuromudulation. Pathways and receptors; Cytoarchitecture; Dopamine - physiology; Fundamental and applied biological sciences. Psychology; Humans; Male; Neural Pathways; Neurons - chemistry; Neurons - cytology; Neurons - enzymology; Papio - anatomy & histology; Parkinson Disease, Secondary - physiopathology; Primates; Substantia nigra; Substantia Nigra - chemistry; Substantia Nigra - cytology; Substantia Nigra - physiology; Tyrosine 3-Monooxygenase - analysis; Tyrosine Hydroxylase; Ventral tegmental area; Ventral Tegmental Area - chemistry; Ventral Tegmental Area - cytology; Ventral Tegmental Area - physiology; Vertebrates: nervous system and sense organs; Tyrosine Hydroxylase; Primates; Cytoarchitecture; Ventral tegmental area; Substantia nigra; Calcium binding proteins; Calcium; Enzyme; Central nervous system; Midbrain; Tyrosine 3-monooxygenase; Binding protein; Vertebrata; Mammalia; Locus niger; Papio ursinus; Simioidea; Dopaminergic neuron; Oxidoreductases; Brain (vertebrata)
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/S0361-9230(98)00128-2

The present study evaluates the cytoarchitecture of midbrain dopaminergic regions in baboons using similar methodology to that recently applied to compare humans and rats. This information is relevant for the interpretation of nonhuman primate models of Parkinson’s disease (PD). The midbrains of four alpha male baboons were serially sectioned into 10 evenly spaced series of 50 μm sections. Series were stained with either cresyl violet or immunohistochemically reacted for tyrosine hydroxylase, substance P, calbindin-D 28k, or parvalbumin. The organization of dopaminergic cell groups and the distribution of proteins within these groups were found to be very similar to that previously described in humans [McRitchie et al., J. Comp. Neurol. 364:121–150; 1996]. Dorsal and ventral tiers of the A9 substantia nigra (SN) pars compacta and all divisions of the A8 and A10 cell groups were identified revealing a high degree of homology in the arrangement of chemically distinct midbrain neurons between primates. The major difference between the organization of human and baboon midbrain dopaminergic neurons is the anteroposterior extent of the dense cell clusters within the SN pars compacta. In baboons the dorsomedial cell cluster is absent at posterior levels. The ventral tier cell clusters, which are targeted by PD in humans, are restricted to the posterior and ventral regions of the SN pars compacta of the baboon. In humans these cell clusters are found throughout the rostrocaudal extent of the SN. These ventral cell clusters have been previously shown to have reciprocal connections with sensorimotor regions of the putamen.