Dissection of the external and internal submucous plexuses of the pig small intestine.

The submucous plexus of large mammals like dog, horse, cow, sheep, pig and man consists of more than one easily identified plexus. The divisions of the submucous plexus are known as the external submucous plexus and the internal submucous plexus. Recently findings have shown that there exists functional differences between the neuronal populations in the subdivisions of the submucous plexus in the small intestine of pigs. We report here how to obtain whole mounts of the submucous plexus containing both the internal and the external submucous plexus. The whole mounts from the submucous plexus of the pig contains almost no muscle and can be used in intracellular neuronal studies without adding nifedipine or equivalent L-type Ca2+ channel blockers to inhibit the contractions of the smooth muscle.