Can we be aware of both visceral and somatic sensations via a single neuronal pathway?

Abstract

Sensory information arising from somatic and visceral area is thought to be respectively transmitted to the brain by two distinct sensory neuronal systems, the somatic and visceral sensory pathway. A novel and unique spinal sensory system, the spinosolitary tract-dorsal column postsynaptic neuronal system (SST-DCPS), was physiologically and anatomically identified. The spinal neurons project to both visceral (the solitary tract nucleus) and somatic sensory (the dorsal column nuclei) nuclei via their branched axons and receive both visceral and somatic sensory information ascending from periphery through dichotomized primary afferents and descending from their targets via their branched axons. The brain might thus be aware of both visceral and somatic sensation via a single SST-DCPS neuronal channel. The finding of SST-DCPS system, as an example, might be considered as an intersection or fuzzy set of the SST and DCPS system and the concept of dichotomy in classification of neurons and neuronal pathways might thus be challenged.