Figure 14.

Distribution of colonic submucosal ganglia. The distance from the inner circular muscle to the epithelium was measured in a minimum of 3 samples from the proximal (N = 177 ganglia), middle (N = 163 ganglia), and distal (N = 155 ganglia) colon. For each whole-mount colon sample, the inner circular layer of muscle was located, and the micron scale was set to 0, then moved in micron steps through the submucosa measuring the distance from the circular muscle for each ganglion encountered. At least 4 different areas were measured in each sample. (A–C) The data were binned according to distance, and the number of ganglia (frequency) per bin is presented. (B) In the midcolon, there are more submucosal ganglia closer to inner circular muscle compared with the proximal or distal colon. (D–F) For each region measured, the distance between ganglia increased approaching the epithelium. The distance from the inner circular muscle was plotted for each region (proximal, middle, distal) for each ganglion measured. The data show, as we have published for human beings,²² that ganglia are distributed throughout the submucosa. The proximal colon sampled was from area B1, the midcolon was from area B2, and the distal colon was from area B3 (Figure 2B).