An analysis of the sensory innervation of the urinary system in the rat

The neuronal cell bodies of the afferent fibers innervating the urinary system and the adrenal gland were identified utilizing the method of the retrograde transport of the fluorescent dyes, fast blue and nuclear yellow. Fast blue was injected into the bladder, left ureter, or left adrenal gland, and nuclear yellow was injected into the left kidney of the same animal. The results demonstrate that each organ receives a discrete sensory innervation and that none of the sensory neurons innervating the organs have collateral inputs to the kidney. The location of the DRG cell bodies indicates that more caudally placed organs are innervated by more caudally placed DRG. These findings confirm previous localization studies of the kidney afferents, and support the effectiveness of the use of the fluorescent dye method to localize peripheral afferent cell bodies.