Abstract
The distribution and morphology of the myenteric plexus in various portions (esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, rectum) of the rat gastrointestinal tract was examined immunocytochemically using and improved peroxidase-antiperoxidase method with antiserum against S100b protein, and by the Champy-Maillet (ZIO) method, and quantified by analytical photography. The myenteric plexus was distributed from the esophagus to the rectum and extended continuously through the various portions of the gastrointestinal tract, being visualized as a network. The network was formed by ganglia and connecting nerve strands, which had a characteristic regular form, although not a geometrical pattern, in each portion. In the esophagus, the fundus and the cecum, there was a loose network consisting of a few small ganglia and nerve strands. In the pylorus, the network was denser than that in the fundus. The density of the network in the small intestine (duodenum, jejunum, ileum) increased in the order duodenum, jejunum and ileum. In the colon, the network was especially dense and the ganglia were confluent with each other, being so large that they were not easy to separate individually. In the rectum, the network showed a regular pattern.
