NADPH-diaphorase-positive neurons in sympathetic ganglia during postnatal ontogenesis

The locations and morphometric characteristics of NADPH-diaphorase (NADPH-d)-positive neurons were identified in the cranial cervical (CCG), stellate (SG), and celiac (CG) ganglia in neonatal rats, mice, and cats and animals aged 10, 20, 30, 60, and 180 days. No NADPH-d-positive neurons were found in rats and mice in any of the age groups studied. In kittens, the majority of NADPH-d-positive neurons were located in the SG, with fewer in the CCG and only occasional neurons in the CG, regardless of age. The proportion of NADPH-d-positive neurons in the SG increased during the first 20 days of life and decreased after 30 days, to the end of the second month of life. The proportion of NADPH-d-reactive neurons in the CCG and CG did not change during ontogenesis. The mean sizes of NADPH-d-positive neurons in different ganglia in animals of the same age were not significantly different. These data lead to the conclusion that the development of NADPH-d-positive neurons with age occurs heterochronously and is complete by the end of the second month of life.