Future Directions

It is obvious that the emergence of tissue engineering has created an air of enthusiasm and optimism for the hundreds of thousands of patients worldwide who suffer from nervous system injury. Studies now indicate that some degree of CNS anatomical regeneration and functional recovery is possible following traumatic spinal cord injury. Although recent findings are encouraging the possibility, a number of factors remain to be clarified. Identification of these factors will help in dissecting the complex environment presented at the CNS lesion site, discovering, and utilizing the signals responsible for inducing a neuron into a highly active growth state. Functional recovery is only contingent upon successful guidance of the regenerating axons to their appropriate targets and the establishment of functional synapses between them. Yet the relationship between the extent of anatomical regeneration and the amount of functional recovery has to be further explored. Design and delivery of physical, chemical, and biological cues to the regenerating axons in a well-controlled manner through a guidance system may be needed to maximize the extent of regeneration and functional recovery.