BBC News reports:
Scientists say they have completely regenerated damaged optic nerves from the eye to the brain in mice.
Experts say the work offers new hope for people with glaucoma, a condition in which raised pressure destroys the optic nerve. It may also eventually help people with spinal cord and other injuries of the central nervous system, they say. The research, by Boston’s Schepens Eye Research Institute, is published in the Journal of Cell Science. Lead researcher Dr Dong Feng Chen said: “This is the closest science has come to regenerating so many nerve fibres over a long distance to reach their targets, and to repair a nerve previously considered irreparably damaged.”
Many tissues in the body continually renew themselves if injured. But the optic nerve, along with other tissues of the central nervous system, does not have this ability, so damage is permanent. The Schepens team had already discovered that the optic nerve’s inability to regenerate was linked to the fact that a key gene called BCL-2 is switched off. They also believed the regeneration process was blocked by the creation, shortly after birth, of a scar on the brain by specialised glial cells. These cells have many functions in the brain, one of which is to create this kind of scar tissue. Potentially the scar puts up a physical as well as molecular barrier to regeneration.
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