Histomorphology of enteric neurons and enteric ganglia in different layers of human fetal colon.

Objective: Literature shows very few studies explaining morphology of enteric neurons and ganglia in humans. This study was aimed at determining the morpho-histology of enteric neurons and ganglia in human fetal colon. Methods: Histological sections of human fetal colon were stained with hematoxylin and eosin, Bielschowsky's silver and Masson's trichrome stains to study the morpho-histology of enteric neurons and ganglia. Results: Enteric neurons scattered in the early weeks of development and ganglionated as the fetal age progresses. Migration of enteric neurons was less and in scattered form during early weeks and as the age progresses it was more and in ganglionated form. Enteric neurons were round, oval, pyramidal and flat in all layers of colon. Enteric ganglia in serosa were oval in early weeks, oval and elongated in late weeks whereas in between the muscle layers and submucosa they were few and oval, irregular and elongated. Distance between the enteric ganglia increased in serosa but fluctuated in the remaining layers as the gestational age progressed. Number of enteric neurons and ganglia was more in serosa and less in other layers during early weeks and as the fetal age progressed they decreased in serosa but increased in other layers. Conclusion: There are various shapes and numbers of enteric neurons and ganglia and distances between the ganglia in different layers of fetal colon.