GRM1 and substance withdrawal syndrome: In another study, blockade of mGluR1 by EMQMCM (5, 10 and 20 mg/kg) was reported to prevent the expression of sensitization to the locomotor effect of morphine, but did not affect the expression of withdrawal syndrome in mice [147], further suggesting that mGluR1 blockade may be of potential benefit in the treatment of opiate seeking behaviour.