ISSN: 2223-2133 (Online), 1815-8986 (Print)
Vol 4. Number 1, July 2004
Origins of colonic preganglionic parasympathetic motoneurons from the central nervous system: a wheatgem agglutinin-horseradish peroxidase study in the ferret (Mus tela putorius furo)
A. Odekunle, E. Uche-Nwachi, A. Adogwa

The Wheat gem Agglutinin-Horseradish Peroxidase (WGA-HRP) transneuronal nerve tracing technique was used to study the localization of colonic preganglionic parasympathetic neurons in the central nervous system of the ferret. The entire colon, from the iliocecal junction to the colorectal junction was subdivided into four segments and the muscular wall of each segment injected separately with the tracer. The ferrets used as controls were also subdivided into four groups. The first group was injected with normal saline, the second group with the tracer following bilateral trunkal vagotomy, the third group intraperitoneally and the fourth group had tracer injection into the hepatic portal vein. The experimental as well as the control ferrets were allowed to survive for 24 to 96 hours after which they were anaesthetized and perfused sequentially with normal saline, buffered fixative, and buffered sucrose.

Serial transverse frozen sections were taken from the brains tern and the sacral segments of the spinal cord of the ferrets. These were then processed for WGA-HRP neurohitochemistry and analyzed under light and dark­field illuminations. The results of the study show that the dorsal motor nucleus of the vagus nerve (DMX) supplies the anterior 3 segments of the colon while the sacral segment of the spinal cord supplies the post 2 segments of the colon.

It is concluded that in the innervation of the colon there is an overlap between the areas supplied by the DMX and those supplied by the sacral segment of the spinal cord.