The adult nervous system has only very limited ability to recover from injury, making the treatment of spinal cord injuries extremely difficult. A paper in the February issue of Nature Neuroscience reports that retinoic acid receptor beta 2 (RARbeta2) may promote regeneration of axons in the adult rat spinal cord and improve functional recovery after spinal cord injury.
If injured, embryonic neurons grow back quite readily, and it is thought that this capability is suppressed in adulthood in part by inhibitory factors present in the adult central nervous system. Injured sensory neurons do regenerate at the site of injury away from the spinal cord (and outside the central nervous system), but are arrested at the transition zone between the peripheral and central nervous systems in the spinal cord (a barrier called the dorsal root entry zone or DREZ).
Liang-Fong Wong and colleagues delivered RARbeta2 to adult sensory neurons in rats using lentivirus before inducing spinal cord injuries. These animals showed significant improvement in various motor tasks, including removing an adhesive tape from their bodies, reaching and grasping food pellets and crossing horizontal ladders or a narrow beam. This functional recovery also correlated with an increased regeneration of the injured axons of these sensory neurons across the DREZ. This work demonstrates that RARbeta2 helps adult injured neurons to regenerate, and opens up new possibilities for spinal cord regeneration therapy.
Liang-Fong Wong (Oxford BioMedica Ltd., Oxford, UK)
Tel: +44 1865 783000, E-mail: email@example.com
Abstract available online.
(C) Nature Neuroscience press release.
Message posted by: Trevor M. D'Souza