Unilateral Electrolytic and 6-Ohda Lesions of the Substantia Nigra in Baboons: Behavioural and Biochemical Data

The role of the substantia nigra (SN) in the control of motor activity has mainly been analyzed through clinical data on Parkinson’s disease in human subjects (Marsden, 1982). This disease has been known for a long time to involve progressive degeneration of the pigmented neurons in the SN (Tretiakoff, 1919; Hassler, 1938). Identification of the nigrostriatal dopaminergic projection (Anden et al., 1964) from these pigmented neurons gave rise to studies in which striatal dopamine (DA) deficit was proved to be responsible for the onset of the symptoms of Parkinsonism, particularly akinesia and rigidity (Hornyckiewicz, 1966; Bernheimer et al., 1973). Besides these clinical observations on human patients, a body of experimental work has been published on animals (see Schultz, 1982) discussing the functional role of the SN.