ML-021

**ML-021** is a selective small molecule antagonist of the muscarinic M4 receptor (M4R), developed by MapLight Therapeutics using their proprietary discovery platform that modulates neuronal signaling pathways. It is designed to address motor deficits in Parkinson's disease by selectively inhibiting M4 receptors expressed on striatal medium spiny neurons, thereby enhancing dopamine release in the basal ganglia without inducing the psychiatric side effects associated with non-selective antipsychotics. As a new molecular entity in the antiparkinsonian class, it is currently in preclinical development with IND-enabling studies expected to complete soon.[1][3][7][9]