LY2119620 is a positive allosteric modulator of the muscarinic M1 and M4 receptors. It has been primarily investigated for its potential in treating cognitive impairments associated with neurological disorders such as Alzheimer's disease and schizophrenia. By enhancing the activity of acetylcholine at M1 receptors, it supports synaptic transmission involved in learning and memory. Its action on M4 receptors may also contribute to antipsychotic effects, making it a candidate for improving both cognitive and psychotic symptoms. The compound has been used in research settings to study receptor modulation and to support the development of more selective muscarinic therapies. It has also been combined with radioligands in PET imaging studies to better understand receptor occupancy and distribution in the brain.