Mary Bartlett Bunge, is a Professor of Cell Biology & Anatomy, Neurological Surgery and Neurology at the University of Miami School of Medicine.

Her major research interest is the development and repair of nervous tissue. She and her team have recently found that grafts of a specific type of nerve cell, called Schwann cells, can provide effective bridges. Bunge's team is currently investigating what other cell types could be transplanted and which factors could be added to the bridge or spinal cord to improve the regenerative growth.

For her contribution to her field and the University of Miami, Dr. Bunge is the recipient of numerous awards, including the 1996 Wakeman Award, honoring advancement of spinal cord injury research, the Javits Neuroscience Investigator Award from the NIH in 1998, and the University of Miami School of Medicine's Senior Laboratory Research Award in 1999. She was also the first winner of the Mika Salpeter Women in Neuroscience Lifetime Achievement Award in 2000.

Bunge sits on the Council for the National Institute of Neurological Disorders and Stroke (NINDS) and is currently a member of the Dana Alliance for Brain Initiatives and the Christopher Reeve Paralysis Foundation Research Consortium.

4.17.01 Roxane Gross asked:
I had an episode of optic neuritis in my right eye caused by Multiple Sclerosis last June. I was told that due to the damage to the myelin and to the nerve tissue of the optic nerve that my sight probably would not return completely. Is it possible, based on what I saw on the program with the Schwann cells, that the nerve tissue and the myelin can be restored in the optic nerve?

Bunge's response:
Roxane,
Some remyelination does occur naturally, but often not complete repair. Even though Schwann cells are not a normal component of the central nervous system (CNS = brain, spinal cord, and, surprisingly, optic nerve and retina!) we know that Schwann cells can myelinate axons in the CNS, and often do after injuries and in MS plaques.

All that means that yes, it may be possible to use Schwann cells to remyelinate optic nerve as well. Many of the best known studies of Schwann cells in rats have been conducted using the optic nerve as a "model" to study re-growth of damaged axons. While this has shown promise in the laboratory, the regenerated/remyelinated axons are generally treated immediately after the damage, and even then, only about 10% of the retinal cells survive and regenerate (when the optic nerve is completely cut). With MS, the possibility of recurrent episodes of demyelination also presents a problem.

To our knowledge, Schwann cell transplantation into the optic nerve has not been attempted clinically , and it is not advisable to assume that such grafts should be tried on you (or anyone) at this point. We now know that in MS, loss of function is actually due to the nerve fiber damage at later stages as well as demyelination; in this case a therapy aimed at remyelination alone would not be effective. Clinical trials are currently being planned for use of Schwann cells in MS, but as a first trial, not as a curative strategy at this point. For more information, you might want to check the web site for The Myelin Project.

4.17.01 Rick Smith asked:
Is there a chance that using Schwann cells might help people with Tinnitus?

Bunge's response:
Rick, To my knowledge the tinnitus is not caused by the same types of nerve damage we are studying in relation to Schwann cell implants. For more information about Tinnitus, its causes and possible treatments, you may want to visit the web site of the American Tinnitus Association, which I found quite informative.

4.17.01 Jim Barricklow asked:
Will Schwann cells work for people with brain stem strokes?

Bunge's response:
Jim,
The damage caused by strokes is mostly due to the loss of nerve cells themselves. In contrast, most of the function lost after spinal cord injury, as described in the program, is actually due to damage of the extensions ("axons") of surviving nerve cells. Because the axons are damaged, their lines of communication are interrupted. The "brain stem" is a name for a particular area of the brain, so the rules it follows in disease and recovery are no different.

It seems likely at this time that more progress will be made using stem cells (as described in the first segment of the program) as a cellular therapy for stroke than Schwann cells. Stem cells offer the possibility of replacing those lost nerve cells, and scientists are exploring whether the brain (or in particular, the brain stem) is able to guide the maturation of the nerve cells and restoration of their connections needed to help stroke patients.

4.17.01 René asked:
Is your research going to be useful for multiple sclerosis?

Bunge's response:
René
Yes, there is a very good chance that Schwann cells could be helpful in treating some MS patients. There is no very good animal model for MS now because the disease itself is more complicated than any of our models of demyelination. However, we and some of our colleagues at Yale University think that the time may be right to consider a first trial of Schwann cells in the clinic. For now such a trial would have to be aimed at the safety of using these cells in the brain or spinal cord, and assessing any evidence at all that a very small graft (small for safety reasons) would be able to remyelinate axons near an MS plaque. The safety issue is especially important in a progressive disease like MS where recurrences are a possibility due to various causes. Again, for more information, you might want to check the web site for The Myelin Project, www.myelin.org which is slated to sponsor the Yale trial. The web site for more information regarding MS is www.nmss.org.