Weiss T, Miltner W H, Huonker R, Friedel R, Schmidt I, Taub E
Department of Biological and Clinical Psychology, Jena, Germany.
Exp Brain Res. 2000 Sep;134(2):199-203. doi: 10.1007/s002210000456.
Recent research indicates that areas of the primary somatosensory (SI) and primary motor cortex show massive cortical reorganization after amputation of the upper arm, forearm or fingers. Most of these studies were carried out months or several years after amputation. In the present study, we describe cortical reorganization of areas in the SI of a patient who underwent amputation of the traumatized middle and ring fingers of his right hand 10 days before cortical magnetic source imaging data were obtained. Somatosensory-evoked magnetic fields (SEF) to mechanical stimuli to the finger tips were recorded and single moving dipoles were calculated using a realistic volume conductor model. Results reveal that the dipoles representing the second and fifth fingers of the affected hand were closer together than the comparable dipoles of the unaffected hand. Our findings demonstrate that neural cell assemblies in SI which formerly represented the right middle and ring fingers of this amputee became reorganized and invaded by neighbouring cell assemblies of the index and little finger of the same hand. These results indicate that functional plasticity occurs within a period of 10 days after amputation.
近期研究表明，在进行上臂、前臂或手指截肢后，初级体感皮层（SI）和初级运动皮层区域会出现大规模的皮层重组。这些研究大多是在截肢数月或数年之后进行的。在本研究中，我们描述了一名患者SI区域的皮层重组情况，该患者在获取皮层磁源成像数据前10天，其右手受伤的中指和环指被截肢。记录了指尖受到机械刺激时的体感诱发磁场（SEF），并使用逼真的容积导体模型计算单个移动偶极子。结果显示，代表患手第二和第五手指的偶极子比未受影响手的类似偶极子靠得更近。我们的研究结果表明，该截肢者SI中先前代表右手中指和环指的神经细胞集合发生了重组，并被同一只手示指和小指的相邻细胞集合侵入。这些结果表明，截肢后10天内会发生功能可塑性。
