ABSTRACT
Animal models which mimic a specific disorder are useful tools for elucidation of the biochemical and pathological abnormalities. Furthermore, animal models are used for evaluation of the therapeutic drug actions and their propensities to produce undesirable side effects. In the last decade we have extensively investigated an animal model in nonhuman primates which replicates certain features of Parkinson's disease (Goldstein et aI., 1973, 1980). This model is produced by placing a surgical unilateral lesion in the ventromedial tegmental (VMT) area of the brain stem in monkeys (Poirier & Sourkes, 1965). In Table 1 the deficits in human parkinsonism are compared with those in monkeys with unilateral VMT lesions of the brain stem. Among the various neurological deficits in Parkinson's disease, only tremor and hypokinesia of the extremities contralateral to the lesion are manifested in these monkeys. Moreover, the administration of levodopa or of various centrally acting dopamine (DA) agonists produces responses similar to those observed in parkinsonian patients (Goldstein et aI., 1973, 1980).
