Dynamic reorganization of referred sensations by movements of phantom limbs.
After amputation of an arm the sensory map of the body changes radically, causing the sensory input from face to 'invade' the original hand area in the brain. As a result, touching the face of the amputee evokes tactile sensations on the phantom. These sensory referrals from the face to phantom hand occur in a stable, topographically organized manner. We now find that volitional movements of the phantom cause striking, systematic shifts in the map along the direction of movement. We conclude that the reorganization of maps is based partly on reversible inhibition of ordinarily silent synapses, not entirely on new anatomical connections. This finding further highlights the dynamic nature of the brain on remarkably short-time scales.
Center for Brain and Cognition, University of California San Diego, La Jolla, California 92093-0109, USA. vramacha@ucsd.edu
Vilayanur S
VS
Ramachandran
David
D
Brang
Paul D
PD
McGeoch
D000328:Adult; D000671:Amputation, Surgical; D001132:Arm / Q000503:physiopathology; D003080:Cold Temperature; D005145:Face / Q000503:physiopathology; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology; D009473:Neuronal Plasticity; D010591:Phantom Limb / Q000503:physiopathology; D010812:Physical Stimulation; D013997:Time Factors; D055698:Touch Perception / Q000502:physiology; D014836:Volition