Xanomeline
Xanomeline is a muscarinic acetylcholine receptor agonist with reasonable selectivity for the M1 and M4 subtypes, though it is also known to act as a M5 receptor antagonist. It has been studied for the treatment of both Alzheimer's disease and schizophrenia, particularly the cognitive and negative symptoms, although gastrointestinal side effects led to a high drop-out rate in clinical trials. Despite this, xanomeline has been shown to have reasonable efficacy for the treatment of schizophrenia symptoms, and one recent human study found robust improvements in verbal learning and short-term memory associated with xanomeline treatment.
