Short-term cortical reorganization by deafferentation of the contralateral sensory cortex.
The topographic arrangement of the human primary somatosensory cortex following deafferentation of the contralateral cortex has been investigated by means of dipole source analysis. Somatosensory-evoked potentials were obtained by electrical stimulation of digit 1 and digit 5 of the left hand before and after anesthesia of digits 2-4 of the right hand during different terms of attention. Anesthesia induced an expansion of the three-dimensional distance between digits 1 and 5. This suggests intercortical plasticity modulated between bilateral primary somatosensory cortical areas, which is unaffected by spatial attention. These changes occur rapidly and are probably mediated by disinhibition of intercortical connections, leading to hyperexcitability of the primary sensory cortex that is contralateral to the region undergoing deafferentation.
Waberski
Till Dino
TD
Department of Neurology, University Hospital Aachen, RWTH Aachen, Germany.
Dieckhöfer
Anne
A
Reminghorst
Ursula
U
Buchner
Helmut
H
Gobbelé
René
R
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology; D001288:Attention / Q000502:physiology; D004558:Electric Stimulation / Q000379:methods; D005073:Evoked Potentials, Somatosensory / Q000502:physiology* / Q000528:radiation effects; D005260:Female; D005385:Fingers / Q000294:innervation / Q000502:physiology; D007839:Functional Laterality; D006801:Humans; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D013003:Somatosensory Cortex / Q000166:cytology / Q000502:physiology*; D013997:Time Factors