VU0155041 is a positive allosteric modulator of metabotropic glutamate receptor 4 (mGluR4) with an EC50 value of 2.5 μM for glutamate response in a thallium flux assay. It is selective for mGluR4, exhibiting no effect on radioligand binding at 67 G protein-coupled receptors, ion channels, and transporters, and lacking antagonist activity at NMDA receptors in striatal medium spiny neurons at a concentration of 10 μM. In vivo, VU0155041 decreases catalepsy induced by haloperidol and reverses askinesias induced by reserpine in rat models of Parkinson’s disease. Chronic treatment with VU0155041 restores social behavior in the Oprm-/- mouse model of autism. It also increases the percentage of time spent in the open arms of the elevated plus maze, a measure of decreased anxiety, in mice.