Calcium indicator intensity in native smooth muscle stripped from day 5 rat pup.

An increase in calcium indicator intensity is in native smooth muscle just prior to depolarization (A) and 0.7 seconds later (B), after depolarization. Regions of black indicate depolarization, while regions of white are decreases in calcium intensity as an artifact of the smooth muscle movement during contraction. 100x magnification, 200-µm scale bar. A plot of calcium indicator intensity (C) within the native smooth muscle show the intense, periodic waves of depolarization.