Ontogeny of cholinergic innervation of thymus in mouse

In this study, identification of cholinergic nerves in the murine thymic rudiments during ontogenetic development, by immunonocytochemical localization of the enzyme cholin acetyltransferase (ChAT) was carried out. Fetal thymic rudiments from day 13 of gestation to the time of birth, and upto 8th post natal week were examined. Contrary to the earlier reports, the results indicate that the thymic rudiment is not innervated during early ontogenetic development and that the first ChAT positive nerve profiles were observed at around day 17/18 of gestation. Significance of cholinergic innervation in thymocyte maturation is suggested.