Anticholinergic drugs
based on tropane alkaloids, including atropine,
scopolamine, and hyoscyamine, have been used for various medicinal
and toxic purposes for millennia. These drugs are competitive antagonists
of acetylcholine muscarinic (M-) receptors that potently modulate
the central nervous system (CNS). Currently used clinically to treat
vomiting, nausea, and bradycardia, as well as alongside other anesthetics
to avoid vagal inhibition, these drugs also evoke potent psychotropic
effects, including characteristic delirium-like states with hallucinations,
altered mood, and cognitive deficits. Given the growing clinical importance
of anti-M deliriant hallucinogens, here we discuss their use and abuse,
clinical importance, and the growing value in preclinical (experimental)
animal models relevant to modeling CNS functions and dysfunctions.