Alterations of M1 and M4 acetylcholine receptors in the genetically dystonic (dt) hamster and moderate antidystonic efficacy of M1 and M4 anticholinergics.

Striatal cholinergic dysfunction has been suggested to play a critical role in the pathophysiology of dystonia. In the dt hamster, a phenotypic model of paroxysmal dystonia, M1 antagonists exerted moderate antidystonic efficacy after acute systemic administration. In the present study, we examined the effects of the M4 preferring antagonist tropicamid and whether long-term systemic or acute intrastriatal injections of the M1 preferring antagonist trihexyphenidyl are more effective in mutant hamsters.