Decrease of [14C]2-deoxyglucose uptake at the intracerebellar nuclei during cerebellar cortex stimulation

The effect of electrical stimulation of the cerebellar cortex at 10-30 c/s on metabolism in the intracerebellar nuclei has been studied using the [14C]2-deoxyglucose method. The experiments, performed on anesthetized or immobilized animals did not produce any detectable changes in the radioautographic labeling of the intracerebellar nuclei compared with controls. Experiments were also performed in animals pretreated with 3-acetylpyridine neurotoxin which selectively destroys the inferior olive and produces an intense labeling of the intracerebellar nuclei. Less marking was observed in restricted regions of the intracerebellar nuclei receiving the axon terminals of the stimulated Purkinje cells if the experiments were done within the first few hours. Following 3-acetylpyridine intoxication, in this early phase, destruction of the inferior olivary cell bodies occurs, but the climbing fibers remain intact. At 2 days or more following 3-acetylpyridine, changes in marking with stimulation could no longer be obtained. The finding is interpreted as being due to an actual reduction of the Purkinje cell activity upon stimulation of the cerebellar cortex, leading to a reduction of the metabolic activity at their presynaptic terminals.