A pathway of NADPH diaphorase positivity between central canal and pial surface at anterior fissure in spinal cord: Supra fissure area with hypothesis configuring from dog, rat, monkey and pigeon

The spinal cord is a cylinder structure in the vertebra and thought a simplified with the gray matter and white matter. Rexed lamination for the gray matter and regional sub-division for whiter matter are completely termed to date. Anterior commissure locates between the central canal and the anterior median fissure. However, some experimental data may still confront with new confined anatomical interpretation. By using NADPH diaphorase [N-d] enzyme histology, we found a vertical oriented neuronal pathway between the central canal and the anterior median fissure in the sacral spinal cord of young adult and aged dog. We used a term "supra fissure area" [SFA] to illustrate the region which consisted of the gray commissure and anterior white commissure. The N-d pathway was notably observable in aged animals. The vertical neurites revealed the cerebrospinal fluid [CSF] contacting neurites between the anterior median fissure and the central canal. We further examined the monkey, rat and pigeon in the region for better understanding of the structure and potential function. The neurodegeneration of N-d dystrophy was detected in the [SFA] in the thoracic spinal cord of the aged monkey. N-d positive fibers were detected in anterior fissure of the rat spinal cord. N-d fibrous structures were also detected in the pigeon spinal cord. These results suggested a new pathway of CSF contacting neurons and the neuronal communications about the central canal.