The distribution within the spinal cord of visceral primary afferent axons carried by the lumbar colonic nerve of the cat.

Horseradish peroxidase taken up by the sensory axons in the lumbar colonic nerves in 5 cats was observed in the dorsal root ganglia and in the spinal cord in segments L1 through L5. Reaction product was observed in Lissauer's tract, the dorsal columns and laminae I, V, VII and X in a pattern typical of visceral primary afferents from other nerves. A small number of preganglionic neurons were also labeled.