Reversal of Experimental Parkinsonism by Lesions of the Subthalamic Nucleus

TLDR

Parkinson’s disease arises from loss of dopaminergic neurons in the substantia nigra, yet the basal ganglia activity changes underlying motor deficits remain poorly defined, with recent evidence implicating heightened subthalamic nucleus activity. The study aimed to determine whether lesions of the subthalamic nucleus could mitigate parkinsonian motor symptoms in MPTP‑treated monkeys. Researchers performed subthalamic nucleus lesions in monkeys rendered parkinsonian by 1‑methyl‑4‑phenyl‑1,2,3,6‑tetrahydropyridine (MPTP) and evaluated motor outcomes. Lesions markedly reduced akinesia, rigidity, and tremor in contralateral limbs, confirming that excessive subthalamic nucleus activity contributes to Parkinson’s motor deficits.

Abstract

Although it is known that Parkinson's disease results from a loss of dopaminergic neurons in the substantia nigra, the resulting alterations in activity in the basal ganglia responsible for parkinsonian motor deficits are still poorly characterized. Recently, increased activity in the subthalamic nucleus has been implicated in the motor abnormalities. To test this hypothesis, the effects of lesions of the subthalamic nucleus were evaluated in monkeys rendered parkinsonian by treatment with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The lesions reduced all of the major motor disturbances in the contralateral limbs, including akinesia, rigidity, and tremor. This result supports the postulated role of excessive activity in the subthalamic nucleus in Parkinson's disease.