Postnatal development of the mucosal plexus in the porcine small and large intestine
Knowledge regarding the foetal and postnatal development of the enteric nervous system is crucial for the understanding of congenital disorders. While lot of information exists regarding the myenteric and submucosal plexuses, the development of the mucosal plexus has not been previously studied. The mucosal innervation seems to play an important role in the local reflex activity of the gut. In this study, we examined the development of enteric mucosal innervation in the pig at various ages of life. Small and large bowel paraffin-embedded specimens were stained with PGP 9.5 and neurofilament protein in three piglets from six age groups (60 and 90 days gestation, newborn, 4 and 12 weeks old, and adult pigs). Small and large bowel demonstrated identical innervation patterns. Myenteric and submucosal plexuses were stained with PGP 9.5 at 60 days gestation. However, the mucosal staining was first noted clearly at the newborn period. By 4 weeks, PGP 9.5 staining was noted in small amounts within the mucosa. Inner proprial and villous fibres were seen ahead in time to the subepithelial fibres. Both inner proprial and villous staining became quiet prominent by 12 weeks of age and remained unchanged into adulthood. However, the subepithelial fibres appear to increase in adulthood. This study demonstrates for the first time that enteric mucosal innervation first appears only at birth. The immaturity of the mucosa generated reflex activity, and secretory functions may have implication in the management of functional intestinal obstruction in the premature infant.
KeywordsMucosal innervation Age-related Porcine
- 2.Mall F (1896) A study of the intestinal contraction. Johns Hopkins Hosp Rep 1:37–75Google Scholar
- 6.Timmermans JP, Scheuermann DW, Stach W, Adriaensen D, De Groodt-Lasseel MH (1990) Distinct distribution of CGRP-, enkephalin-, galanin-, neuromedin U-, neuropeptide Y-, somatostatin-, substance P-, VIP- and serotonin-containing neurons in the two submucosal ganglionic neural networks of the porcine small intestine. Cell Tissue Res 260:367–379PubMedCrossRefGoogle Scholar
- 9.Mestres P, Diener M, Rummel W (1992) Electron microscopy of the mucosal plexus of the rat colon. Acta Anat (Basel) 143:275–282Google Scholar
- 10.Mestres P, Diener M, Rummel W (1992) Histo- and immunocytochemical characterization of the neurons of the mucosal plexus in the rat colon. Acta Anat (Basel) 143:268–274Google Scholar
- 17.Timmermans JP, Adriaensen D, Cornelissen W, Scheuermann DW (1997) Structural organization and neuropeptide distribution in the mammalian enteric nervous system, with special attention to those components involved in mucosal reflexes. Comp Biochem Physiol A Physiol 118:331–340PubMedCrossRefGoogle Scholar