the differential inhibitory effects of these agonists on the evoked neurotransmitter release indicate that the opioid receptors mediating presynaptic inhibition of [ 3h ] noradrenaline ( na , cortex ) , [ 14c ] acetylcholine ( ach , striatum ) and [ 3h ] da ( striatum ) release represent mu , delta and kappa receptors , respectively .
C0034801
opioid receptors
C0064239
kappa receptors