Enhanced binding of metabotropic glutamate receptor type 5 (mGluR5) PET tracers in the brain of parkinsonian primates.

The interplay between dopamine and glutamate in the basal ganglia regulates critical aspects of motor learning and behavior. Metabotropic glutamate receptors (mGluR) are increasingly regarded as key modulators of neuroadaptation in these circuits, in normal and disease conditions. Using PET, we demonstrate a significant upregulation of mGluR type 5 in the striatum of MPTP-lesioned, parkinsonian primates, providing the basis for therapeutic exploration of mGluR5 antagonists in Parkinson disease.