biostudies-literatureWalwyn WNIDA NIH HHS134-43https://www.ebi.ac.uk/biostudies/studies/S-EPMC2701458biostudies-literatureUnknown76(1)Recombinant micro and delta opioid receptors expressed in cell lines can form heterodimers with distinctive properties and trafficking. However, a role for opioid receptor heterodimerization in neurons has yet to be identified. The inhibitory coupling of opioid receptors to voltage-dependent Ca(2+) channels (VDCCs) is a relatively inefficient process and therefore provides a sensitive assay of altered opioid receptor function and expression. We examined micro-receptor coupling to VDCCs in dorsal root ganglion neurons of delta(+/+), delta(+/-), and delta(-/-) mice. Neurons deficient in delta receptors exhibited reduced inhibition of VDCCs by morphine and [D-Ala(2),Phe(4),Gly(5)-ol]-enkephalin (DAMGO). An absence of delta receptors caused reduced efficacy of DAMGO without affecting potency. Molecular pharmacologyDelta receptors are required for full inhibitory coupling of mu-receptors to voltage-dependent Ca(2+) channels in dorsal root ganglion neurons.PMC2701458DA05010P50 DA005010DA00484Walwyn WHales TGMaga MEvans CJJohn SfalseDelta receptors are required for full inhibitory coupling of mu-receptors to voltage-dependent Ca(2+) channels in dorsal root ganglion neurons.Recombinant micro and delta opioid receptors expressed in cell lines can form heterodimers with distinctive properties and trafficking. However, a role for opioid receptor heterodimerization in neurons has yet to be identified. The inhibitory coupling of opioid receptors to voltage-dependent Ca(2+) channels (VDCCs) is a relatively inefficient process and therefore provides a sensitive assay of altered opioid receptor function and expression. We examined micro-receptor coupling to VDCCs in dorsal root ganglion neurons of delta(+/+), delta(+/-), and delta(-/-) mice. Neurons deficient in delta receptors exhibited reduced inhibition of VDCCs by morphine and [D-Ala(2),Phe(4),Gly(5)-ol]-enkephalin (DAMGO). An absence of delta receptors caused reduced efficacy of DAMGO without affecting potency. 2009-01-01T00:00:00Z2009 Jul2026-05-03T14:51:34.303Z2019-03-27T00:23:10ZS-EPMC27014581935724710.1124/mol.109.055913