Hallucinations cholinergic system

The answers arc 488-d, 489-h. (Katzang, pp 108-112, 1020.) Atropine blocks muscarinic cholinergic transmission in the brain and in the autonomic nervous system. The result is dry mouth, thirst, dry and hot skin, tachycardia, urinary retention, ataxia, restlessness, excitement, and hallucinations, followed by stupor, delirium, respiratory depression, coma, and death. 

Accordingly, several of the neurochemical and neuroanatomical systems considered to be involved in arousal and consciousness, i.e. Meynert nucleus, pontine reticular formation, locus coeruleus and raphe nucleus with their cholinergic, noradrenergic and serotonergic afferents (Delacourt, 1995) are affected in PD. In addition, the dopamine system, in particular the mesolim-bocortical system, is involved in cognition and motivation, and possibly in the emergence of positive psychotic symptoms such as hallucinations and delusions. 

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