GRM5 and Cognitive impairment: Among the suspected mechanisms, potentiating of NMDA response by positive allosteric modulators (PAMs) [68] is suspected to improve cognitive deficits of this disease [67] while the antipsychotic effects of PAMs could be the consequence of the modulatory effect on the mesolimbic dopaminergic pathway [3], as suggested by the decrease in the basal dopamine levels in the nucleus accumbens induced by ADX47273 (mGluR5 PAM) [69].