The forms of argyrophilic ganglion cells in the myenteric plexus throughout the gastrointestinal tract of the opossum.

In the small intestine, the myenteric plexus contains several different forms of ganglion cells. We examined the whole gut of the American opossum to see if these forms exist in other organs. Sections were stained by silver-impregnation. About half the ganglion cells were argyrophilic in all regions. Argyrophilic cells were described as to dendrite shape (filiform or lamellar), number, and grouping on the nerve cell body (radiating or focal), and in respect to nuclear position (central or peripheral). Cells with lamellar dendrites were sparse in esophagus (less than 5%), in gastric fundus (17.2%) and in antrum (8.2%), increased from duodenum (18.5%) to ileum (64.3%) and increased along the colon from the cecum (62.3%) to the rectum (94.9%). The proportion of cells with filiform dendrites diminished correspondingly along the gut. The number of dendrites per cell increased caudad along the gut. Cells with focally distributed dendrites were rare in all regions. More cells had central nuclei than peripheral nuclei in all regions, and nuclear position did not correlate with dendrite morphology. Thus, the forms of myenteric plexus ganglion cells differ systematically in the gut. The results do not support the idea that a specific function can be assigned to a ganglion cell of a specific form.