Optimized Administration of the M PAM VU0467154 Demonstrates Broad Efficacy, but Limited Effective Concentrations in Mice.

Hypofunction of cholinergic circuits and diminished cholinergic tone have been associated with the neurodevelopmental disorder Rett syndrome (RTT). Specifically, deletion of in cholinergic neurons evokes the same social and cognitive phenotypes in mice seen with global knockout, and decreased choline acetyltransferase activity and vesamicol binding have been reported in RTT autopsy samples. Further, we recently identified significant decreases in muscarinic acetylcholine receptor subtype 4 (M) expression in both the motor cortex and cerebellum of RTT patient autopsies and established proof of concept that an acute dose of the positive allosteric modulator (PAM) VU0467154 (VU154) rescued phenotypes in mice.

Clinical and Preclinical Evidence for M Muscarinic Acetylcholine Receptor Potentiation as a Therapeutic Approach for Rett Syndrome.

Rett syndrome (RTT) is a neurodevelopmental disorder that is characterized by developmental regression, loss of communicative ability, stereotyped hand wringing, cognitive impairment, and central apneas, among many other symptoms. RTT is caused by loss-of-function mutations in a methyl-reader known as methyl-CpG-binding protein 2 (MeCP2), a protein that links epigenetic changes on DNA to larger chromatin structure. Historically, target identification for RTT has relied heavily on Mecp2 knockout mice; however, we recently adopted the alternative approach of performing transcriptional profiling in autopsy samples from RTT patients.