NO-ergic neurons of the methasympathetic nervous system in postnatal development

Abstract

The aim of the study was to identify the localization, percentage and morphometric characteristics of NPY-immunoreactive (IR) neurons in the intramural ganglia of the myenteric (MP) and submucous plexus (SP) of the small intestine of rats of different age groups. Material and methods. The work was performed on Wistar rats aged 1, 10, 20, 30, 60 days and 2 years using immunohistochemical methods. Results. nNOS-IR neurons are detected in the small intestine from the moment of birth and throughout the remaining studied age periods. In the intramural ganglia of the MP, the percentage varied from 43 ± 4.3 in the newborns to 41 ± 3.8 in the 60 day old rats and significantly decreased to 27 ± 2.5 in aged rats. In the SP ganglia, nNOS-IR neurons were detected in most number in newborns (64 ± 3.1 %;). In the next 20 days, the percentage decreased significantly to several percent, but in old rats it increased again to 27 ± 1.9. Conclusions. Thus, in the early postnatal and senile period, nNOS expresses a greater number of enteric neurons in comparison with young and adult.