Nerve Regeneration Done in Lab

Apr 09, 2002

ORLANDO, Fla., Apr 08, 2002 (United Press International via COMTEX) -- Nerve regeneration has been achieved in rat brain cells in the laboratory, which someday could lead to new therapies for human spinal cord injuries, multiple sclerosis and other neurological conditions, researchers reported Monday at the 223rd national meeting of the American Chemical Society.

"In this study we have found one of the key players in the process by which nerves get the signal not to regenerate," said lead investigator Dr. Ronald Schnaar, professor of pharmacology and neuroscience at Johns Hopkins University Medical School in Baltimore, Md. "By knowing that, we and others in the field can work together to develop technologies to enhance nerve regeneration."

Schnaar also said he believes these results add to a growing body of evidence that repairing spinal cord injury -- a procedure once thought impossible -- may one day occur.

Nerve cell axons, which transmit electrical signals, are wrapped in an insulating layer of cells called myelin. Just as rubber insulation protects electrical wires, myelin allows electricity to be conducted properly in brain and spinal cord nerves. Loss of myelin leads to diseases such as multiple sclerosis and Guillain Barre syndrome.

"Myelin also has a dark side," Schnaar said. "When nerve axons are damaged, such as in spinal cord injuries, myelin stops them from regenerating. In large part, myelin blockade of axon regeneration is responsible for the lack of recovery from a nervous system injury."

As part of healthy nerve cell life, certain molecules within the myelin exchange signals with specific molecules on the surface of the axons -- sort of a "molecular handshake," Schnaar explained. But when nerve injury occurs, the signals become abnormal, thereby preventing axons from regenerating and new nerve cells from growing.

The researchers identified four chemicals that correct the abnormal chemical signals and restore the process of nerve cell regeneration. But so far, the regeneration has been achieved only in Petri dishes under controlled laboratory conditions.

Although this discovery is promising, "nerve damage is very much more complex than our laboratory conditions and this new knowledge, by itself, is unlikely to provide aid to those suffering with nerve injury," Schnaar cautioned. "However, it is our hope that our discoveries, along with other new discoveries on the molecular basis for nerve regeneration, will help in the search for therapies to improve functional recovery after nervous system injury or disease."

Schnaar's research "is at the forefront of a current recognition of the fundamental importance of this class of lipids in biomedical science," Rashmi Bansal, professor of neuroscience at the University of Connecticut Medical School in Farmington, told United Press International.

"There are important implications here for pathological situations, in particular nerve regeneration after injury or degenerative diseases, including multiple sclerosis, a disease in which nerve deterioration has recently been re-emphasized," Bansal added.

Testing continues using live animals to see the lab findings can be transferred successfully into living systems. Preliminary results are not yet available, Schnaar said.

The research was funded by the National Institutes of Health, the National Multiple Sclerosis Society and the Stollof Family Fund.

Copyright 2002 by United Press International.
Submitted  8/27/2003 8:23:49 PM