A special type of ganglion cells in the submucous plexus of mouse small intestine.
The perikarya of sensory neurons have been reported frequently from electrophysiological studies of the plexus submucosus of many mammalian digestive tracts, but the fine structural characteristics of those cells or ganglia have rarely been demonstrated. Therefore, we conducted an electron microscopic study in search of possible sensory perikarya in the plexus of the mouse small intestine. Many ganglion cells scattered over the plexus submucosus possessed a few areas of fine granules frequently adjacent to dense bodies in their perikaryonal cytoplasm, as revealed first by Wilson et al. [23], who were unable to explain the significance, of this finding. On the other hand, one type of ganglion with a special three-dimensional structure was observed in the same plexus. This ganglion was composed of one central perikaryon, one innermost cellular semiperfect cover of the Schwann cell, a middle two-layered cellular coat, an outer neuropil and an outermost external lamina. The surface of the central perikaryon, which differed from those of the other ganglion cells, was almost entirely covered with one Schwann cell, most probably for isolation from various kinds of external electrical and/or chemical inputs. Dumbbell-shaped vesicles containing endings that were presumed to be sensory, were frequently localized in the outer neuropil of this ganglion. It is likely that this perikaryon belongs to the sensory ganglion cells and so acts as an important factor in the peristaltic reflex arc.
Yamamoto
M
M
Institute of Functional Anatomy, Yamano College of Aesthetics, Tokyo, Japan.
D000818:Animals; D005260:Female; D017950:Ganglia, Sensory / Q000648:ultrastructure*; D007421:Intestine, Small / Q000294:innervation*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D013368:Submucous Plexus / Q000648:ultrastructure*