The origin of postganglionic and sensory axons in the cervical sympathetic trunk of the cat: a horseradish peroxidase study.

The composition of the cervical sympathetic trunk (CST) in the cat is still not completely understood. The present study investigates, by the horseradish peroxidase (HRP) method of tracing neuronal connections, the presence of postganglionic and sensory neurons projecting via the CST. Following sympathectomy at the midcervical level and the application of HRP crystals to the cut ends of the CST which had been isolated from the surrounding by a 1.5% solution of agar-agar, labelled neurons were seen in the superior cervical (SCG), stellate (SG), inferior vagal ganglia (IVG), and spinal ganglia C8-T8. The maximum number of labelled neurons was 536 in the SCG, 460 in the SG, 180 in the IVG, and 104 in spinal ganglia C8-T8.