Axonal Regeneration in the Sensory Dorsal Column Pathway

This review provides a short historical background to the field of axonal regeneration and discusses the advances made in over 100 studies between 2007 and 2012 in understanding the molecular mechanisms underlying the conditioning lesion and regeneration of primary sensory axons in the dorsal columns of the spinal cord. Treatment strategies to stimulate axon growth and reinnervation of the spinal cord through the dorsal root entry zone and of the dorsal column nuclei in the medulla are highlighted. Major breakthroughs have been made, e.g., reinnervating the nucleus gracilis in the medulla using neurotrophic factor gradients and grafts as relays and identifying chondroitin sulfate proteoglycan receptors. The experimental accessibility of the dorsal column axons has also resulted in new technological advances, including live imaging. Last, future directions are discussed, including some challenges of translation to humans.