M1 Muscarinic receptor KO (Chrm1 tm1Jwe) Mouse

M1 Muscarinic Receptor Knockout: support involvement in cognitive processes.

The five Muscarinic Acetylcholine (ACh) receptors are G-protein coupled receptors (M1R-M5R). M1R, M3R and M5R selectively couple to Gq/G11; M2R and M4R selectively couple to Gi/Go. M1R knockout mice are viable and fertile, and have no major morphological abnormalities.

M1 muscarinic receptors are located in higher brain regions of the central nervous system that are involved in cognitive processes. Studies in M1R knockout mice show that M1 receptors may be involved in cortical memory functions that require interactions between the cerebral cortex and hippocampus. Supporting a role for M1 receptor activation in cognition, muscarinic agonist-induced activation of the MAPK pathway, which plays an important role in synaptic plasticity and many cognitive functions, is virtually abolished in primary cortical cultures or CA1 hippocampal pyramidal neurons in M1R knockout mice.