PROMOTING AXON REGENERATION
There are several obstacles that impede successful regeneration after a spinal cord injury. Firstly adult axons have a diminished intrinsic capacity for regenerating. Secondly, a glial scar forms at the injury site. The scar is rich in growth inhibitory molecules that act as chemical barriers to regeneration. Our strategies are largely based on enhancing the functional regeneration of severed axons. To do this, we concurrently address the two major obstacles to axonal regeneration after injury: 1) the inhibitory environment of the glial scar; 2) the inability of most adult CNS neurons to mount a robust growth response. We use a combination of growth supportive transplants, modification of the inhibitory environment that is associated with the glial scar, and the treating with various agents (e.g. pharmacological and viral vectors) to enhance the intrinsic ability of mature axons to regrow. We assess the extent of axonal regeneration histologically and electrophysiologically. We also use a variety of functional outcome measures to determine whether these regenerated axons successfully and appropriately integrate into neural circuits and mediate behavioral recovery.