First Author | Baker SA | Year | 2021 |
Journal | Elife | Volume | 10 |
PubMed ID | 33399536 | Mgi Jnum | J:313861 |
Mgi Id | MGI:6803254 | Doi | 10.7554/eLife.64099 |
Citation | Baker SA, et al. (2021) Ca(2+) signaling driving pacemaker activity in submucosal interstitial cells of Cajal in the murine colon. Elife 10:e64099 |
abstractText | Interstitial cells of Cajal (ICC) generate pacemaker activity responsible for phasic contractions in colonic segmentation and peristalsis. ICC along the submucosal border (ICC-SM) contribute to mixing and more complex patterns of colonic motility. We show the complex patterns of Ca(2+) signaling in ICC-SM and the relationship between ICC-SM Ca(2+) transients and activation of smooth muscle cells (SMCs) using optogenetic tools. ICC-SM displayed rhythmic firing of Ca(2+)transients ~ 15 cpm and paced adjacent SMCs. The majority of spontaneous activity occurred in regular Ca(2+) transients clusters (CTCs) that propagated through the network. CTCs were organized and dependent upon Ca(2+) entry through voltage-dependent Ca(2+) conductances, L- and T-type Ca(2+) channels. Removal of Ca(2+) from the external solution abolished CTCs. Ca(2+) release mechanisms reduced the duration and amplitude of Ca(2+) transients but did not block CTCs. These data reveal how colonic pacemaker ICC-SM exhibit complex Ca(2+-)firing patterns and drive smooth muscle activity and overall colonic contractions. |