3D imaging and digital tracing of local process projections and connectivity of hpChAT-ir cholinergic neurons in the mucosa (A,B) and myenteric plexus (C-E) of human sigmoid colon using Imaris 9.2 for Neuroscientists. Some traceable green nerve fibers, digitally yellow-labeled in A and extracted in B, show the pattern of local cholinergic network in the mucosa. The nerve cell bodies and fibers are depicted in red and yellow, respectively. C, A 3D Image shows hpChAT-ir cholinergic structures in the myenteric plexus. Both Dogiel type I neurons with small soma, one long and several short processes, and Dogiel type II neurons characterized by a large and smooth soma with several long processes are clearly stained for hpChAT, with labeling being stronger in type II than type I. D and E, Some clearly stained hpChAT-ir cell bodies and fibers in C are digitally labeled in D, and extracted in E