Congenitally altered motor experience alters somatotopic organization of human primary motor cortex-猫眼课题宝

先天改变的运动体验改变了人类初级运动皮层的体位组织

DOI：

发表时间：

2009

期刊：

Proceedings of the National Academy of Sciences of the United States of America

影响因子：

11.1

通讯作者：

中科院分区：

综合性期刊1区

文献类型：

作者：

M. C. Stoeckel;R. Seitz;C. Buetefisch

人类运动发育被认为是基因和经验之间复杂相互作用的结果。众所周知的灵长类初级运动皮层（M1）的躯体位置组织出现在出生后。虽然适应性的变化，以响应学习和使用发生在整个生活中，躯体是保持重组仅限于修改内的主要身体部位的代表。我们报告了一个独特的机会，以评估经验的影响，在人类运动皮层的基因决定的躯体组织。我们研究了先天性手功能受损和代偿性熟练使用脚的受试者的运动“脚”表征。M1的功能性磁共振成像（fMRI）和经颅磁刺激（TMS）显示，足部位于M1的经典内侧足部区域，并且在外侧“手”区域附近的非相邻皮质中有几厘米远。这两个区域都直接输出到支配足部肌肉的脊髓运动神经元，并且与行为相关，因为TMS对任一区域的实验破坏改变了反应时间。我们证明了一个独特的，nonsomatotopically组织的M1在人类中，这是一个功能的严重改变运动行为从最早的发展阶段。我们的结果意味着，在早期运动发育期间，经验可能在遗传决定的神经网络的形成中发挥比之前假设的更关键的作用。

Human motor development is thought to result from a complex interaction between genes and experience. The well-known somatotopic organization of the primate primary motor cortex (M1) emerges postnatally. Although adaptive changes in response to learning and use occur throughout life, somatotopy is maintained as reorganization is restricted to modifications within major body part representations. We report of a unique opportunity to evaluate the influence of experience on the genetically determined somatotopic organization of motor cortex in humans. We examined the motor “foot” representation in subjects with congenitally compromised hand function and compensatory skillful foot use. Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) of M1 revealed that the foot was represented in the classical medial foot area of M1 and was several centimetres away in nonadjacent cortex in the vicinity of the lateral “hand” area. Both areas had direct output to the spinal motor neurons innervating foot muscles and were behaviorally relevant because experimental disruption of either area by TMS altered reaction times. We demonstrate a unique, nonsomatotopically organized M1 in humans, which emerged as a function of grossly altered motor behavior from the earliest stages of development. Our results imply that during early motor development experience may play a more critical role in the shaping of genetically determined neural networks than previously assumed.

Topographic specificity of corticospinal connections formed in explant coculture.