Discrepancies between c‐Kit positive and Ano1 positive ICC ‐ SMP in the W/W v and wild‐type mouse colon; relationships with motor patterns and calcium transients

Background Interstitial cells of Cajal associated with the submuscular plexus ( ICC ‐ SMP ) generate omnipresent slow‐wave activity in the colon and are associated with prominent motor patterns. Our aim was to investigate colon motor dysfunction in W/W v mice in which the ICC are reportedly reduced. Methods Whole organ colon motility was studied using spatio‐temporal mapping; immunohistochemical staining was carried out for c‐Kit and Ano1; calcium imaging was applied to ICC ‐ SMP . Key Results Discrepancies between Ano1 and c‐Kit staining were found in both wild‐type and W/W v colon. ICC ‐ SMP were reduced to ~50% in the W/W v mouse colon according to c‐Kit immunohistochemistry, but Ano1 staining indicated a normal network of ICC ‐ SMP . The latter was consistent with rhythmic calcium transients occurring at the submucosal border of the colon in W/W v mice, similar to the rhythmic transients in wild‐type ICC ‐ SMP . Furthermore, the motor pattern associated with ICC ‐ SMP pacemaking, the so‐called ‘ripples’ were normal in the W/W v colon. Conclusions & Inferences c‐Kit is not a reliable marker for quantifying ICC ‐ SMP in the mouse colon. Ano1 staining revealed a normal network of ICC ‐ SMP consistent with the presence of a normal ‘ripples’ motor pattern. We detected a class of Ano1 positive c‐Kit negative cells that do not depend on Kit expression for maintenance, a feature shared with ICC progenitors.