3,5-Dibromobenzonitrile is a chemical compound that can be found at high concentrations in the brain of patients with neurodegenerative diseases. 3,5-Dibromobenzonitrile has been shown to bind to metabotropic glutamate receptor 5 (mGluR5) and activate it; it also binds to glutamate receptors. The uptake of 3,5-dibromobenzonitrile by the body is dependent on its molecular orbital type and the functional groups present. Brain tissue samples from patients with neurodegenerative diseases have shown an increase in the amount of 3,5-dibromobenzonitrile binding to mGluR5. This increased binding may be due to a change in the molecular orbitals or functional groups on mGluR5, as well as an increase in expression of this receptor in diseased brains.