Interestingly, a combined administration of MPEP with A2A receptor antagonists reversed akinesia induced by 6-OHDA or reserpine in rodents, suggesting that combining mGluR5 and A2A receptor blockade may be beneficial in the symptomatic treatment of PD (Coccurello et al., 2004; Kachroo et al., 2005). The gene discussed is GRM5; the disease is Parkinson disease.