Related Experiment Video
Updated: Jul 18, 2026

Characterization of Neuromuscular Junctions in Mice by Combined Confocal and Super-Resolution Microscopy
Published on: December 8, 2021
M1-M3 muscarinic acetylcholine receptor-deficient mice: novel phenotypes
Dinesh Gautam1, Alokesh Duttaroy, Yinghong Cui
1Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Abstract:
The five muscarinic acetylcholine receptors (M1-M5 mAChRs) mediate a very large number of important physiological functions (Caulfield, 1993; Caulfield and Birdsall, 1998; Wess, 2004). Because of the lack of small molecule ligands endowed with a high degree of receptor subtype selectivity and the fact that most tissues or cell types express two or more mAChR subtypes, identification of the physiological and pathophysiological roles of the individual mAChR subtypes has proved to be a challenging task. To overcome these difficulties, we recently generated mutant mouse lines deficient in each of the five mAChR genes (M1R-/- mice, M2R-/- mice, M3R-/- mice, etc. [Wess, 2004]). Phenotyping studies showed that each of the five mutant mouse lines displayed characteristic physiological, pharmacological, behavioral, biochemical, or neurochemical deficits (Wess, 2004). This chapter summarizes recent findings dealing with the importance of the M2mAChR for cognitive processes and the roles of the M1 and M3 mAChRs in mediating stimulation of glandular secretion.
Related Concept Videos
Cholinergic Receptors: Muscarinic
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Cholinergic Antagonists: Pharmacological Actions
Gastrointestinal Effects: Antimuscarinics reduce gut contractions, increase gastric emptying, and slow intestinal transit. They partly inhibit gastric acid secretion...

