A. DOReGFP-IR colocalized in myenteric neurons of distal colon with MOR-IR (arrowheads), but MOR-IR was also detected in large neurons that did not express DOReGFP-IR (arrowhead with asterisk) and in interstitial cells of Cajal (asterisks). B. MOR-IR was present at the cell surface of some myenteric neurons, including those positive for DOReGFP-IR (arrowhead). C. Dermorphin-Cy3 (DerCy3) trafficked to endosomes of myenteric neurons of distal colon, including neurons expressing DOReGFP-IR (arrowheads). D. DOReGFP-IR colocalized with MOR-IR in some submucosal neurons of the ileum (arrowheads), but MOR-IR was also detected in neurons that did not express DOReGFP-IR (arrowhead with asterisk). Scale, 20 μm.