Changes in dopamine release in caudate nuclei and substantia nigrae after electrical stimulation of the posterior interposate nucleus of cat cerebellum.

The effect of unilateral electrical stimulation of the posterior interposate nucleus of the cerebellum was examined on the activity of the nigro-striatal dopaminergic pathways on both sides of the brain in alpha-chloralose anaesthetized cats. Push-pull cannulae were inserted into both caudate nuclei and both substantia nigrae to measure the release of [3H]dopamine ( [3H]DA) which was continuously synthesized from L-[3,5-3H]tyrosine. The stimulation of the cerebellum induced long-lasting well-organized changes in [3H]DA release in the four structures: an increased release of the neurotransmitter in both the contralateral caudate nucleus and the ipsilateral substantia nigra and a reduction in the release of DA from the ipsilateral caudate nucleus and the contralateral substantia nigra. This finding supports the concept of a functional interaction between the cerebellum and the basal ganglia.