Human Informatics and Interaction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, 305-8568, Japan.
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Ibaraki, 305-8577, Japan.
Sci Rep. 2020 Apr 15;10(1):6458. doi: 10.1038/s41598-020-63617-0.
Because compensatory changes in brain activity underlie functional recovery after brain damage, monitoring of these changes will help to improve rehabilitation effectiveness. Functional near-infrared spectroscopy (fNIRS) has the potential to measure brain activity in freely moving subjects. We recently established a macaque model of internal capsule infarcts and an fNIRS system for use in the monkey brain. Here, we used these systems to study motor recovery in two macaques, for which focal infarcts of different sizes were induced in the posterior limb of the internal capsule. Immediately after the injection, flaccid paralysis was observed in the hand contralateral to the injected hemisphere. Thereafter, dexterous hand movements gradually recovered over months. After movement recovery, task-evoked hemodynamic responses increased in the ventral premotor cortex (PMv). The response in the PMv of the infarcted (i.e., ipsilesional) hemisphere increased in the monkey that had received less damage. In contrast, the PMv of the non-infarcted (contralesional) hemisphere was recruited in the monkey with more damage. A pharmacological inactivation experiment with muscimol suggested the involvement of these areas in dexterous hand movements during recovery. These results indicate that fNIRS can be used to evaluate brain activity changes crucial for functional recovery after brain damage.
由于大脑损伤后的功能恢复是基于大脑活动的代偿性变化，因此监测这些变化将有助于提高康复效果。功能近红外光谱（fNIRS）具有测量自由运动受试者大脑活动的潜力。我们最近建立了一种内囊梗死的猕猴模型和一种用于猴脑的 fNIRS 系统。在这里，我们使用这些系统研究了两只猕猴的运动恢复情况，它们的内囊后肢被注射了不同大小的局灶性梗死。注射后，对侧手部立即出现弛缓性瘫痪。此后，灵巧的手部运动在数月内逐渐恢复。运动恢复后，任务诱发的血流动力学反应在腹侧运动前皮质（PMv）增加。接受较小损伤的猕猴，其梗死（即同侧）半球的 PMv 反应增加。相比之下，损伤较大的猕猴，非梗死（对侧）半球的 PMv 被募集。用 muscimol 进行的药理学失活实验表明，这些区域参与了恢复过程中灵巧手部运动。这些结果表明，fNIRS 可用于评估大脑活动变化，这些变化对大脑损伤后的功能恢复至关重要。
