Adrenal medullae of 15-day-old and adult rats were injected with a solution of horseradish peroxidase. Preganglionic neurons in the 15-day-old rats were readily identified in the intermediate zone of the spinal cord after staining with diaminobenzidine tetrahydrochloride; horseradish peroxidase uptake could not be demonstrated in the adult rats. Adrenal preganglionic neurons were distributed between spinal segments T1 and L1. Approximately 50% of the neurons were located within segments T7 to T10. Only slight differences were observed between the distributions of neurons projecting to the right and left adrenal. The maximum velocity of transport of horseradish peroxidase was calculated to be approximately 4 mm/hr. Horseradish peroxidase filled neurons so that it was possible to observe the major orientation of perikarya and dendrites. The perikarya and dendrites exhibited a predominately transverse orientation.
ASJC Scopus subject areas
- Developmental Neuroscience