Giving Motor Maps A Hand
The cerebral cortex contains many orderly representations of the body surface, and it is well known that these maps shift after injuries such as amputation of a leg or an arm. Cortical representations of body regions surrounding the amputation often 'invade' the cortical territory previously occupied by the now missing limb, and it is likely that such cortical remapping underlies some of the symptoms of phantom limbs. But what happens to the redrawn cortical map if the damage to the body can be restored? Angela Sirigu and colleagues address this question by studying a remarkable patient who lost both of his hands in an accident, and then received a successful bilateral hand transplant (Nature Neuroscience, Vol. 4, No. 7, 01 July 2001). The authors used fMRI to study the organization of the patient's motor and sensory cortex before the hand graft surgery. At that time, the subject was using a prosthetic device. They noted that intact portions of the forelimb had come to be represented in the area that normally would have represented the hand. Then, the authors re-measured the cortical maps at several points following the surgery. They found that over a period of several months the patient's motor and sensory cortex progressively acquired a map that resembled one that would be found in a healthy subject. This study provides further evidence for the remarkable plasticity of the adult brain.
CONTACT: Dr. Angela Sirigu
Institut des Sciences Cognitives
67, BD Pinel
tel: +33 4 37 91 12 12
fax: +33 4 37 91 12 10
(C) Nature Neuroscience press release.
Message posted by: Trevor M. D'Souza