Possible Sensory Endings in the Submucous Plexus of Mouse Small Intestine

Abstract

Mitochondria-rich varicosities of unmyelinated nerve fibers are found in the submucosa of the mouse small intestine, and are consieered sensory endings. They appear in the submucous plexus as well as in the myentric plexus. The endings also c ontain abundant elongated dumbbell-shaped vesicles (about 250Å×1500Å)but are devoid of small granular and agranular vesicles as seen in autonomic endings. The possibility that the dumbbellshaped vesicles might be derived from neurotubules is discussed.