The Effect of Altered Function of Dopaminergic Neurones on the Cholinergic System in the Striatum

Abstract

This chapter discusses the effect of altered function of dopaminergic neurones on the cholinergic system in the striatum. A functional link between the dopaminergic and cholinergic systems in the striatum has been demonstrated pharmacologically with the use of specific and potent dopamine (DA) receptor agonists, antagonists, and DA depletors. The DA antagonists and depletors stimulate the release and turnover of striatal ACh, and reduce steady-state ACh levels; in contrast, direct- or indirect-acting DA agonists increase the steady-state level of ACh, and reduce its turnover. The concerted results of biochemical, pharmacological, and lesion studies have provided strong evidence for a link between two neuronal systems (dopaminergic and cholinergic) in the CNS. It appears from the data that dopaminergic neurones arising in the substantia nigra synapse with and exert inhibitory influence upon cholinergic neurones intrinsic to the neostriatum of rat. Alteration of dopaminergic activity by drugs, lesions, and possibly by mental disease can affect cholinergic activity in the neostriatum.