GROWTH-INHIBITORS
Martin Oudega, Ph.D. • Patrick M. Wood, Ph.D.

Great attention was focused earlier this year on reports describing the genetic sequence of an important growth inhibiting protein called nogo. This inhibitor is found on myelin, and is thought to block growth in myelinated white matter of the brain and spinal cord. Work by Swiss researcher, Dr. Martin Schwab has shown that antibodies to nogo can be used in the injured rodent spinal cord to promote regeneration of some nerve fibers growing from the brain down the spinal cord.

Recent work by Dr. Martin Oudega and an international collaborative team that included Dr. Schwab, and Dr. Theo Hagg, of Canada, showed a surprising result. Looking at the sensory nerves that carry information from the body to the brain, the team found that blocking nogo did not improve regeneration beyond a peripheral nerve graft. On the other hand, adding nerve growth factor (NGF) above the peripheral nerve bridge did promote sensory nerve growth within the spinal cord. This technique has been studied extensively by Drs. Oudega and Hagg, but this is the first test of the combination of nogo-inhibitors with NGF. The combination used in this experiment was no more effective than NGF alone. The researchers concluded that while nogo is a powerful inhibitor of some types of spinal cord regeneration, it does not play a major inhibitory role for regenerating sensory fibers.