http://www.miamiproject.miami.edu/news.asp
Researchers have learned that a reason the fibers do not re-enter the spinal cord beyond Schwann cell grafts is likely because of an inhibitory Environment that exists within the spinal cord. These observations led Pearse and Bunge to consider a combination strategy to help damaged neurons overcome inhibitory signals after injury.

Research colleague Marie Filbin, Ph.D. of Hunter College, New York, recently demonstrated that cyclic adenosine monophosphate (cAMP), a messenger molecule that influences the inner workings of cells, is important for growth of axons across inhibitory environments. Interested in knowing what happens to cAMP after injury, Pearse and Bunge’s team determined the levels of cAMP in the brain and spinal cord following a contusion injury. They found that the levels of cAMP drop well below normal within one day of injury.

The Combination
To help counteract the drop in levels of cAMP after injury, Pearse and Bunge administered rolipram (panel A) at the time of injury. Rolipram is a drug that prevents the initial decrease in cAMP. This drug’s safety has already been tested in humans. It is also able to travel through the blood stream and is easily administered by subcutaneous injection (under the skin.)