(A) Representative immunohistochemical staining of CAD and S-100B. The immunopositive areas displayed brown in the regions of the myenteric plexus, and the nuclei were counterstained blue by Hematoxylin and evenly distributed across the section. CAD immunopositive cells in the colonic intramuscular layer of the sham CES group decreased significantly as compared with that of the control; CES recovered the expression levels of CAD in the myenteric plexus. High level of S-100B immunopositive cells appeared in the colonic intramuscular layer of the control, while the sham CES group showed significantly decreased S-100B immunopositive cells; CES recovered the expression levels of S-100B in the myenteric plexus. (B,C) Immunopositive areas were detected by an inverted microscope (Nikon, Japan). ImageJ software was employed for the quantitative evaluation of the immunopositive areas. The relative CAD/S100B-immunopositive area (%) (compared with the control group) was used as the y-axis. The data were represented as mean ± S.D. (****P<0.0001 versus CES).