Fig. 13.

Distribution of A3-immunoreactive neurons in the myenteric plexus of the rat colon. A3-immunoreactive neuronal cell bodies were quantitated in 1-cm lengths of longitudinal muscle myenteric plexus preparations from ascending colon to distal rectum for the whole length of the colon. Ascending and transverse colon have the lowest expression of A3-immunoreactive neurons. Descending colon and rectum have a 3- to 4-fold greater expression of A3-immunoreactive neurons than proximal colon. Similar results were obtained in 1 other animal (not shown).