Ultrastructural observations in the rat ileal mucosa of possible epithelial "taste cells" and submucosal sensory neurons.

Electronmicroscopical studies of the rat ileum have demonstrated the presence of submucosal neuronlike cells located just under the basal lamina of intestinal crypts. These cells had dendrite-like processes and frequently made contacts with adjacent submucosal nerve terminals. Furthermore, within the mucosa epithelial "clear' cells with apical cytoplasmic processes into the gut lumen and basal cytoplasmic processes extending underneath adjacent epithelial cells were demonstrated. The "clear' cells were devoid of secretory granules, as e.g. endocrine cells, and had a morphological resemblance to taste cells. Occasionally the "clear' cells made contacts with submucosal nerve terminals. The possibility that the "clear' cells and submucosal neuronlike cells represent a receptive function within the intestine is discussed.