Stinear Cathy M, Coxon James P, Byblow Winston D
Movement Neuroscience Laboratory, Department of Sport & Exercise Science, University of Auckland, New Zealand.
Neurosci Biobehav Rev. 2009 May;33(5):662-73. doi: 10.1016/j.neubiorev.2008.08.013. Epub 2008 Aug 26.
Processes that engage frontal cortex and the basal ganglia are responsible for the prevention of planned movements. Here, we review the role of primary motor cortex (M1) in this function. M1 receives and integrates input from a range of cortical and subcortical sites. It is also the final cortical processing site for voluntary motor commands, before they descend to the spinal cord. Inhibitory networks within M1 may be an important mechanism for the prevention or suppression of movement. Transcranial magnetic stimulation (TMS) has been used to evaluate corticospinal excitability and intracortical inhibition in humans, during the performance of a range of movement selection and prevention tasks. This review explores how M1 intracortical inhibition is selectively reduced to initiate desired voluntary movements, while movement prevention is associated with rapid, non-selective recruitment of inhibition within M1. The relationship between deficient intracortical inhibition and behavioural inhibition is also explored. Examples of neuropathology are reviewed, including focal dystonia, attention deficit hyperactivity disorder and Tourette syndrome. The strengths and limitations of TMS in the study of movement prevention are also discussed. While the precise functional links between M1 neuronal populations and the fronto-basal-ganglia network activated by movement prevention have yet to be elucidated, it is clear that M1 plays a critical role in the final processing stage of response inhibition.
涉及额叶皮质和基底神经节的过程负责阻止计划中的动作。在此，我们综述初级运动皮层（M1）在该功能中的作用。M1接收并整合来自一系列皮质和皮质下部位的输入。它也是自主运动指令在下行至脊髓之前的最后一个皮质处理位点。M1内的抑制性网络可能是阻止或抑制动作的重要机制。在一系列动作选择和阻止任务的执行过程中，经颅磁刺激（TMS）已被用于评估人类的皮质脊髓兴奋性和皮质内抑制。本综述探讨了M1皮质内抑制如何被选择性降低以启动所需的自主运动，而动作阻止则与M1内抑制的快速、非选择性募集有关。还探讨了皮质内抑制不足与行为抑制之间的关系。综述了神经病理学的实例，包括局灶性肌张力障碍、注意力缺陷多动障碍和妥瑞氏综合征。还讨论了TMS在动作阻止研究中的优势和局限性。虽然M1神经元群体与由动作阻止激活的额-基底-神经节网络之间的确切功能联系尚未阐明，但很明显M1在反应抑制的最终处理阶段起着关键作用。
