Last updated: Fri, Jul 26, 2024
Descending projection fibers originate in the brain and penetrate the length and depth of the spinal gray matter, including the dorsal horns. These include both inhibiting and exciting projections, and they serve to regulate the sensitivity of spinal neurons, including nociceptive neurons. As we've already seen, they can inhibit or enhance the flexor reflex. Additional description of the functions of these connections will be described in the section, The Descending Tracts and Descending Pain Modulation.