Department of Integrative Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Automotive Human Factors Research Centre, National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan.
J Physiol. 2018 Nov;596(21):5099-5118. doi: 10.1113/JP276956. Epub 2018 Sep 30.
Some cortical areas are believed to transmit a descending signal in association with motor intention and/or effort that regulates the cardiovascular system during exercise (termed central command). However, there was no evidence for the specific cortical area responding prior to arbitrary motor execution and in proportion to the motor effort. Using a multichannel near-infrared spectroscopy system, we found that the oxygenation of the dorsolateral and ventrolateral prefrontal cortices on the right side increases in a feedforward- and motor effort-dependent manner during voluntary one-armed cranking with the right arm. This finding may suggest a role of the dorsolateral and ventrolateral prefrontal cortices in triggering off central command and may help us to understand impaired regulation of the cardiovascular system in association with lesion of the prefrontal cortex.
Output from higher brain centres (termed central command) regulates the cardiovascular system during exercise in a feedforward- and motor effort-dependent manner. This study aimed to determine a cortical area responding prior to arbitrarily started exercise and in proportion to the effort during exercise. The oxygenation responses in the frontal and frontoparietal areas during one-armed cranking with the right arm were measured using multichannel near-infrared spectroscopy, as indexes of regional blood flow responses, in 20 subjects. The intensity of voluntary exercise was 30% and 60% of the maximal voluntary effort (MVE). At the start period of both voluntary cranking tasks, the oxygenation increased (P < 0.05) only in the lateral and dorsal part of the dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC) and sensorimotor cortices. Then, the oxygenation increased gradually in all cortical areas during cranking at 60% MVE, while oxygenation increased only in the frontoparietal area and some of the frontal area during cranking at 30% MVE. The rating of perceived exertion to the cranking tasks correlated (P < 0.05) with the oxygenation responses on the right side of the lateral-DLPFC (r = 0.46) and VLPFC (r = 0.48) and the frontopolar areas (r = 0.47-0.49). Motor-driven passive one-armed cranking decreased the oxygenation in most cortical areas, except the contralateral frontoparietal areas. Accordingly, the lateral-DLPFC and VLPFC on the right side would respond in a feedforward- and motor effort-dependent manner during voluntary exercise with the right arm. Afferent inputs from mechanosensitive afferents may decrease the cortical oxygenation.
一些皮质区域被认为在运动期间传递与运动意图和/或努力相关的下行信号，以调节心血管系统（称为中枢命令）。然而，没有证据表明在任意运动执行之前，特定的皮质区域会做出响应，并且与运动努力成比例。使用多通道近红外光谱系统，我们发现右侧背外侧和腹外侧前额叶皮质的氧合作用以顺行和运动努力依赖的方式增加，在自愿用右臂单臂曲柄运动时。这一发现可能表明背外侧和腹外侧前额叶皮质在引发中枢命令方面发挥作用，并可能有助于我们理解与前额叶皮质损伤相关的心血管系统调节受损。
来自更高脑区的输出（称为中枢命令）以顺行和运动努力依赖的方式调节运动期间的心血管系统。本研究旨在确定在任意开始运动之前以及与运动期间努力相对应的皮质区域做出响应。使用多通道近红外光谱测量 20 名受试者在使用右臂单臂曲柄运动期间前额和额顶区域的氧合反应，作为局部血流反应的指标。自愿曲柄运动的强度为最大自愿用力（MVE）的 30%和 60%。在两个自愿曲柄任务的起始阶段，只有在背外侧前额叶皮质（DLPFC）、腹外侧前额叶皮质（VLPFC）和感觉运动皮质的外侧和背侧部分，氧合作用增加（P<0.05）。然后，在 60%MVE 曲柄运动期间，所有皮质区域的氧合作用逐渐增加，而在 30%MVE 曲柄运动期间，仅在前顶叶区域和一些额叶区域增加氧合作用。曲柄任务的感知用力与右侧外侧-DLPFC（r=0.46）和 VLPFC（r=0.48）以及额极区（r=0.47-0.49）的氧合反应相关（P<0.05）。机械敏感传入传入的电机驱动被动单臂曲柄运动会降低大多数皮质区域的氧合作用，除了对侧额顶区域。因此，右侧背外侧和腹外侧前额叶皮质会以顺行和运动努力依赖的方式对右侧自愿运动做出响应。机械敏感传入传入的传入输入可能会降低皮质的氧合作用。
