DIFFERENTIATION OF CHOLINERGIC CELLS IN THE RAT GUT DURING PRENATAL AND POSTNATAL LIFE

In the present work we studied the distribution and number of choliner gic neurons in the rat stomach, ileum and colon starting from prenatal life up to the adult animal. Cryo-cut sections of the three regions w ere incubated in the presence of the primary choline acetyltransferase (ChAT)-antibody and the immunoreaction was observed under an epifluor escence microscope and photographed. Our results demonstrate that chol inergic neurons are already present during prenatal life in the stomac h and ileum, that several steps characterize cholinergic cell differen tiation during postnatal life with a consistent delay in the appearanc e of ChAT-immunoreactivity (IR) in the submucous plexus compared to th e myenteric plexus, and that the complete development is accomplished with weaning. In the colon the total number of ChAT-IR cells does not change from the suckling period to adulthood; a significantly larger n umber of ChAT-IR cells is found in the ileum of 5-day-old rats than in that of adult rats.