Preganglionic innervation of the adrenal gland of the rat using horseradish peroxidase

Using the tetramethyl benzidine method for the demonstration of horseradish peroxidase, it was possible to label retrogradely spinal neurons whose axons project to the adrenal medulla in both young and adult rats. In both age groups, labeled neurons were found in the ipsilateral intermediolateral cell column of the T2 through T13 segments of the spinal cord, with most of the labeling in the T6 to T10 segments. The neurons labeled with horseradish peroxidase also demonstrated a strong acetylcholinesterase activity.