Muscarinic acetylcholine receptor family (M1–M5) (CHRM1–CHRM5)

Muscarinic acetylcholine receptors (M1–M5) are a family of G protein-coupled receptors widely expressed throughout the central and peripheral nervous systems[7]. The M1 receptor, in particular, plays a critical role in modulating cognitive functions and brain circuits relevant to neuropsychiatric disorders such as schizophrenia[4][10]. M1–M5 receptors respond to the neurotransmitter acetylcholine, mediating various physiological functions including neural plasticity, memory, and modulation of dopamine pathways[4][10]. Certain drugs, such as xanomeline and N-desmethylclozapine, act as agonists or allosteric modulators of muscarinic receptors and are under investigation for the treatment of cognitive and negative symptoms in schizophrenia[1][4][10]. Risperidone, however, does not act as an antagonist at muscarinic receptors and is not considered to exert its effects through direct interaction with the M1–M5 subtypes; its primary targets are dopamine D2 and serotonin 5-HT2A receptors[2][3][5][8]. Therefore, "Risperidone - Muscarinic M1–M5" is not a correct designation for a molecular target.

Other names

Muscarinic receptor M1CHRM1Acetylcholine receptor M1Muscarinic receptor familyCholinergic receptor muscarinic M1–M5

Agonists enhance cholinergic neurotransmission (e.g., xanomeline, N-desmethylclozapine as M1 agonists); Antagonists inhibit cholinergic signaling (e.g., biperiden, scopolamine); Positive allosteric modulators potentiate effects of endogenous acetylcholine.