Neuropharmacology of the extrapyramidal system.

The neuropharmacology and neuroanatomy of the extrapyramidal system are complex; however, in its most reductionistic state, this system is often described as a balance between the actions of dopamine and acetylcholine. In this paper, a thorough investigation of the neuroanatomy and neuropharmacology of the extrapyramidal system is undertaken, and an attempt is made to delineate the roles of other neurotransmitters and neuromodulators that play an important role in its functioning. To demonstrate the therapeutic complexity of extrapyramidal system movement disorders, clinical literature is briefly reviewed to show the relative efficacies of anticholinergic and prodopaminergic antiparkinsonian agents in treating neuroleptic-induced extrapyramidal side effects and to show how drugs that affect alternative neurotransmitter systems have also been used to treat these same side effects.