the mu-selective agonist [ d-ala2 , n-me-phe4 , gly5-ol ] enkephalin ( dago ) or the delta-selective agonist [ d-pen2 , d-pen5 ] enkephalin ( dpdpe ) was injected into a lateral cerebral ventricle , then rats were stressed by restraint .
C0014298
enkephalin
C0525856
dpdpe