Altered Tonic Activity of Neurons in the Globus Pallidus and Subthalamic Nucleus in the Primate MPTP Model of Parkinsonism

In recent years single cell recording studies in the basal ganglia of behaving animals have contributed significantly to our understanding of the role of these structures in normal motor function (see DeLong et al., 1984; Alexander et al., 1986). Little is known, however, of the changes in neuronal activity in the basal ganglia responsible for the profound abnormalities of motor function associated with diseases of these structures, such as Parkinson’s and Huntington’s diseases. The development of a suitable primate model of parkinsonism utilizing MPTP provides the opportunity to address these important questions. The systemic administration of MPTP, a selective neurotoxin, to monkeys produces a parkinsonian syndrome with rigidity, akinesia, and bradykinesia (Burns et al., 1983; Langston et al., 1984). Single cell recording in this animal model may provide direct information regarding the pathophysiology of the parkinsonian syndrome. Here we report preliminary observations of altered neuronal activity in the external and internal segments of the globus pallidus (GPe, GPi) and subthalamic nucleus (STN) in an animal rendered parkinsonian with MPTP.