RESUMEN
The aim of this study was to examine the distribution of cholinergic and nitroxidergic neurons in the spinal cord (SC) of adult and newborn rats. Using immunohistochemical demonstration of choline acetyltransferase (ChAT) and nitric oxide synthase (NOS), cervical portions of SC were studied in newborn (n=5) and adult (n=5) Wistar rats. It was found that ChAT-positive neurons were localized in the anterior horns of the SC, while individual cells were located in of SC posterior horns, in the central gray matter and at the boundary of VI-VII Rexed laminae. Nitroxidergic neurons were located in the superficial layers of SC posterior horns of grey matter, in the central gray matter and in the area of VI-VII Rexed laminae. It is found that SC of newborn and adult rats contained cholinergic neurons expressing NOS. Detection of cells containing both enzymes already at postnatal Day 1, suggests that they were formed in rat SC during prenatal ontogenesis
