Developmental Changes in NO-Containing Sympathetic Neurons in the Spinal Cord in Rats

Objectives. To determine the locations, percentage composition, and morphometric characteristics of sympathetic preganglionic neurons containing NO synthase (NOS) in the spinal cord of rats. Materials and methods. Experiments were performed on 35 white female Wistar rats aged 3, 10, 20, 30, and 60 days, 6 months, and 3 years. Immunohistochemical detection of NOS and the acetylcholine synthesis enzyme choline acetyltransferase (CAT) was performed on sections of spinal cord made at the level of segment T2. The areas of nerve cells and the proportions of immunoreactive neurons were determined. Results. Most sympathetic preganglionic neurons in the spinal cord of neonates and 10-day-old rats contained both NOS and CAT. At these age groups, rats also had a population of NOS-positive/CAT-negative neurons (26% in neonates and 8% in 10-day-old animals), this population was not seen in older animals. During the first 20 days, the proportion of NOS-immunopositive neurons decreased significantly, while the population of CAT-positive neurons increased. Conclusions. There was a reduction in the number of sympathetic preganglionic neurons expressing NOS during early postnatal ontogeny, which may influence the mechanisms of NO-ergic sympathetic transmission.

from Physiology via xlomafota13 on Inoreader https://ift.tt/2C8RtF7
via IFTTT