Department of Neuroscience, Graduate School of Medicine, Kyoto University, Kyoto, 606-8501, Japan.
Department of Neurology, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
Nat Commun. 2024 Aug 22;15(1):6762. doi: 10.1038/s41467-024-51070-w.
Whether and how the non-lesional sensorimotor cortex is activated and contributes to post-injury motor recovery is controversial. Here, we investigated the role of interhemispheric pathway from the contralesional to ipsilesional premotor cortex in activating the ipsilesional sensorimotor cortex and promoting recovery after lesioning the lateral corticospinal tract at the cervical cord, by unidirectional chemogenetic blockade in macaques. The blockade impaired dexterous hand movements during the early recovery stage. Electrocorticographical recording showed that the low frequency band activity of the ipsilesional premotor cortex around movement onset was decreased by the blockade during the early recovery stage, while it was increased by blockade during the intact state and late recovery stage. These results demonstrate that action of the interhemispheric pathway changed from inhibition to facilitation, to involve the ipsilesional sensorimotor cortex in hand movements during the early recovery stage. The present study offers insights into the stage-dependent role of the interhemispheric pathway and a therapeutic target in the early recovery stage after lesioning of the corticospinal tract.
非病灶感觉运动皮层是否以及如何被激活并有助于损伤后的运动恢复存在争议。在这里，我们通过在猕猴中进行单向化学遗传阻断来研究来自对侧运动前皮质到同侧运动前皮质的半球间通路在激活同侧感觉运动皮层和促进颈脊髓外侧皮质脊髓束损伤后的恢复中的作用。阻断在早期恢复阶段会损害灵巧的手部运动。脑电记录显示，在早期恢复阶段，阻断会降低同侧运动前皮质在运动起始时的低频带活动，而在完整状态和晚期恢复阶段，阻断会增加低频带活动。这些结果表明，半球间通路的作用从抑制变为促进，在早期恢复阶段参与手部运动的同侧感觉运动皮层。本研究为损伤皮质脊髓束后的早期恢复阶段半球间通路的时相依赖性作用和治疗靶点提供了深入了解。
