The Study On Brain Plasticity Of Both Hand And Face In Somatosensory Cortex After Hegu Acupoint Disinhibition Sensory Afferent

ObjectiveTo investigate initial cortical reactions to injury of the median and radial nerves to the hands of adult primates, this would expound the biological mechanism of "the specificity of ora-facial area and Hegu acupoint".MethodsAfter transecting the radial and median nerves to the hand of two monkeys, microelectrode extracellular recording techniques was applied to import acupuncture stimuli responses of ora-facial area and Hegu acupoint in anesthetized monkey and find the receptive field. To observe initial cortical reactions to injury of the median and radial nerves to the hands of adult primates.ResultsThere were14points (from A to N) which had been recorded in the brain somatosensory area S1of Rhesus monkeys. Before transecting the radial and median nerves to the hand, the receptive fields of Point A to E were the facial region, while Point F to N’s were hand region. The receptive field of Point A was base of the thumb to the fingertips of the hairy hand. Both B and D’s receptive field were thenar of the glabrous hand. The receptive field of Point C was base of the thumb and index finger to the fingertips of the glabrous hand. The receptive field of Point E was base of the thumb to the fingertips of the glabrous hand. The receptive field of Point F、G and H were the area which were covered by mentalis and depressor muscle of lower lip on the left side of the face. The receptive field of Point K and I were the area which covered by nasalis muscle and musculus levator labii superioris on the left side of the nose portion. The receptive field of Point J and L were the area which covered by buccinators and Blasius’ duct on the left side of face. The receptive field of Point M and N were the area which covered by masseter muscle、depressor anguli oris and depressor muscle of lower lip on the left side of face.After1hour of transecting the radial and median nerves to the hand, The neurons of Point A to F were not responsive to the stimulate, while other points’ receptive field were remain the same.After7hours of transecting the radial and median nerves to the hand, The neurons of Point A to D were not responsive to the stimulate, the receptive field of Point E was changed from base of the thumb to the fingertips of the glabrous hand to the area which were covered by mentalis and depressor muscle of lower lip on the left side of the face. Yet other points’ receptive field were remain the same.After24hours of transecting the radial and median nerves to the hand, The neurons of Point A and B were not responsive to the stimulate, the receptive field of Point C、D and E were turn into he area which were covered by mentalis and depressor muscle of lower lip on the left side of the face. but other points’ receptive field were remain the same.ConclusionThere was functional reorganization in adult monkey cortex after Hegu acupoint disinhibition sensory afferent, Specific contact with the surface of the body was more prominent, and associated with brain plasticity closely. It may be one of the biological mechanism of "the specific relation of ora-facial area and Hegu acupoint" in physiological condition.