Neurons projecting rostrally in the hypogastric nerve of the cat.

Afferent, pre- and postganglionic nerve cell bodies projecting rostrally in the hypogastric nerve have been labelled retrogradely with horseradish peroxidase, in order to study number and location of these neurons. Labelled somata were found in the ganglia of the pelvic plexus, in sacral spinal ganglia and in the sacral spinal cord. They were located mainly ipsilateral with a maximum of afferent and preganglionic neurons at the segmental level S2. The numbers of labelled cells were small (less than 3.5% of all axons in the hypogastric nerve) and varied considerably between animals. Therefore this population of neurons is probably small and of limited functional significance. Enteric neurons (probably afferent) that have their cell bodies within the pelvic viscera and project rostrally in the hypogastric nerve to the inferior mesenteric ganglion were not included in this study and might be of more functional importance.