Promoting regeneration of rubro- and corticospinal neurons after acute and chronic thoracic transection by combining infusion of BDNF to the cell body with spinal cellular bridges

About 1,000 Canadians are victims of acute spinal cord injury every year and a total of 30,000 individuals live with this disabling condition in the chronic state. Aside from the personal loss of quality of life and opportunities, the costs for Society are staggering. Numerous experimental therapies to promote spinal cord regeneration have shown promise in animal models of acute spinal injury, but their effectiveness is greatly diminished with a delay in administration. The Tetzlaff laboratory has recently shown in the rat that a specific group of nerve cells (rubrospinal neurons), which are involved in fine motor control, can survive after spinal cord injury for more than a year in a highly shrunken state and do not die as previously believed. Application of a specific factor (BDNF) normalized their shrunken size and stimulated their regeneration into nerve bridges. This work opens the door to promote their regeneration after chronic spinal cord injury. Dr. Bretzner will characterize the functional properties of these neurons after acute and chronic injury and treatment with BDNF. Moreover, he will study their regeneration across cell bridges of the spinal cord injury site and how their make functional contacts to the lower spinal cord. These studies will contribute to the development of strategies to promote regeneration after chronic spinal cord injury in humans.