Research on tissue growth

An Irish researcher will next month begin ground-breaking experiments which, if successful, could lead to new treatments for spinal cord injuries.

The work, by Prof Marie Filbin, who is Distinguished Professor of Biology at Hunter College New York and is from Lurgan, Co Armagh, builds on the earlier discovery of a substance that encourages nerve tissue to regrow. "This is the first molecular handle we have on this," she said yesterday during the final day of the Life and Death of the Brain conference at Trinity College Dublin.

She will use elevated levels of the substance, a common "messaging" protein found in humans and other mammals known as cyclicAMP, to encourage regrowth of a rat's severed spinal cord.

Scientists have for years been trying to understand the chemical processes involved in the growth of nerve tissues. These grow readily before birth and for a time in infancy, but the body does not retain the ability to heal damage and regrow nerves for long.

The processes involved in nerve growth and regeneration are highly complex, but Prof Filbin's group discovered that cyclicAMP had a central role in encouraging regrowth. She found that infant mice had high levels of cyclic AMP, but this dropped off quickly after birth. The protein was only one small element of the process, she added. It seemed to be an initiator that brings into play a cascade of other substances that controlled growth.

There were two challenges to overcome in encouraging nerve growth, she said. As with all other tissue types, damaged nerves heal and a scar is formed which produces a barrier which blocks nerve growth. Nerve tissue also releases a range of proteins which tightly regulate growth, powerful inhibitors which prevent inappropriate nerve development.