Identification of preganglionic parasympathetic neurons in the sacral spinal cord of the cat

The preganglionic parasympathetic neurons in the sacral spinal cord of the cat have been demonstrated by retrogade changes following section of the pelvic nerve. Transection of the pelvic nerve twice, a week apart, was necessary to produce reliable signs of chromatolysis in the preganglionic neurons. Serial sections of the sacral spinal cord were made and the location of affected cells plotted. The sacral parasympathetic nucleus was located in the intermediate region of S‐2 and S‐3. The majority of the perikarya were located in the intermediolateral cell column, but a significant number were also found in the intermediomedial column. The distribution of afferent fibers in the pelvic nerve was demonstrated by chromatolysis in cells of the dorsal root ganglia. Retrograde changes were limited to the ganglia of S‐2 and S‐3 in five cats, while a few cells with chromatolysis were found also in the S‐1 ganglion of four cats.