we have previously ( dauge et al . 1988 ) demonstrated that injection of the mu agonist [ d-ala2 , mephe4 , gly-ol5 ] -enkephalin ( dago ) or the delta agonist [ d-thr2 , leu5 ] -enkephalyl-thr6 ( dtlet ) into the rat nucleus accumbens ( n.acc . ) , or nucleus caudatus ( n.caud . ) induced a hypoactivity followed by hyperactivity 150 min later in the case of the mu agonist and a hyperactivity in the case of the delta agonist .
C0014298
enkephalin
C0525773
dago