Vagal sensors in the rat duodenal mucosa: distribution and structure as revealed by in vivo DiI-tracing

Hans Rudolf Berthoud, Michael Kressel, Helen E Raybould, Winfried L. Neuhuber

Research output: Contribution to journalArticle

156 Citations (Scopus)

Abstract

Results from functional studies point to the importance of chemoreceptive endings in the duodenum innervated by vagal afferents in the regulation of gastrointestinal functions such as gastric emptying and acid secretion, as well as in the process of satiation. In order to visualize the vagal sensory innervation of this gut segment, vagal afferents were selectively labeled in vivo by injecting the lipophilic carbocyanine dye DiI into either the left or the right nodose ganglion of young adult rats. Thick cryostat sections or whole-mounted peels of muscularis externa or submucosa of formalinfixed tissue were analyzed with conventional and/or confocal microscopy. In the mucosa, many DiI-labeled vagal afferent fibers were found with terminal arborizations mainly between the crypts and the villous lamina propria. In both areas, vagal terminal branches came in close contact with the basal lamina, but did not appear to penetrate it so as to make direct contact with epithelial cells. Labeled vagal afferent fibers in the villous and cryptic lamina propria were found to be in intimate anatomical contact with fibrocyte-like cells that may belong to the class of interstitial cells of Cajal, and with small granular cells that might be granulocytes or histiocytes. Although our analysis was not quantitative, and considering that labeling was unilateral and not complete, it appears that the overall density of vagal afferent mucosal innervation was variable; many villi showed no evidence for innervation while other areas had quite dense networks of arborizing terminal fibers in several neighboring villi. Analysis of separate whole-mounted muscularis externa and submucosa peels revealed the presence of large bundles of labeled afferent fibers running within the myenteric plexus along the mesenteric attachment primarily in an aboral direction, with individual fibers turning towards the antimesenteric pole, and either penetrating into the submucosa or forming the characteristic intraganglionic laminar endings (IGLEs). Although the possibility of individual fibers issuing collaterals to myenteric IGLEs and at the same time to mucosal terminals was not demonstrated, it cannot be ruled out. These anatomical findings are discussed in the context of absorptive mechanisms for the different macronutrients and the implication of enteroendocrine cells such as CCK-containing cells that may function as intestinal "taste cells".

Original languageEnglish (US)
Pages (from-to)203-212
Number of pages10
JournalAnatomy and Embryology
Volume191
Issue number3
DOIs
StatePublished - Mar 1995
Externally publishedYes

Fingerprint

Mucous Membrane
Nodose Ganglion
Enteroendocrine Cells
Interstitial Cells of Cajal
Satiation
Myenteric Plexus
Histiocytes
Gastric Emptying
Gastric Acid
Duodenum
Granulocytes
Basement Membrane
Confocal Microscopy
Young Adult
Coloring Agents
Epithelial Cells

Keywords

  • Confocal microscopy
  • Nodose ganglion
  • Small intestine
  • Vagal afferents
  • Vagus nerve

ASJC Scopus subject areas

  • Embryology
  • Anatomy
  • Developmental Biology
  • Cell Biology

Cite this

Vagal sensors in the rat duodenal mucosa : distribution and structure as revealed by in vivo DiI-tracing. / Berthoud, Hans Rudolf; Kressel, Michael; Raybould, Helen E; Neuhuber, Winfried L.

In: Anatomy and Embryology, Vol. 191, No. 3, 03.1995, p. 203-212.

Research output: Contribution to journalArticle

Berthoud, Hans Rudolf ; Kressel, Michael ; Raybould, Helen E ; Neuhuber, Winfried L. / Vagal sensors in the rat duodenal mucosa : distribution and structure as revealed by in vivo DiI-tracing. In: Anatomy and Embryology. 1995 ; Vol. 191, No. 3. pp. 203-212.
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