GRM2 and Cognitive impairment: While future studies will need to directly assess the behavioral significance of altered corticostriatal mGluR2/3 and mGluR7 receptors, these findings are of particular significance as recent evidence suggests that agents which positively modulate function of mGluR2/3 receptors (e.g., modafinil, [64]) also inhibit meth seeking [63], [74] and may possess therapeutic potential both for the prevention of relapse and improving cognitive deficits in meth-dependent individuals [75], [76].