Distribution of capsaicin-sensitive urinary bladder afferents in the rat spinal cord.

The capsaicin-sensitive afferent innervation of the urinary bladder and the central nervous system distribution of urinary bladder afferents have been studied in the rat. Capsaicin-sensitive primary sensory neurones supplying the urinary bladder have been found in two groups of spinal ganglia located in the Th13-L2 and L6-S1 segments. Capsaicin-sensitive primary sensory afferents from the bladder terminate within Rexed's laminae I, V and X, and in the dorsal gray commissure of the lumbosacral spinal cord. In addition, the results point to a possible vagal sensory innervation of the urinary bladder.