Chaney Remi, Garnier Philippe, Quirié Aurore, Martin Alain, Prigent-Tessier Anne, Marie Christine
INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences de Santé, Dijon, France.
Département Génie Biologique, IUT, Dijon, France.
Front Physiol. 2022 Mar 23;13:811118. doi: 10.3389/fphys.2022.811118. eCollection 2022.
Elevation of cerebral blood flow (CBF) may contribute to the cerebral benefits of the regular practice of physical exercise. Surprisingly, while electrically induced contraction of a large muscular mass is a potential substitute for physical exercise to improve cognition, its effect on CBF remains to be investigated. Therefore, the present study investigated CBF in the cortical area representing the hindlimb, the hippocampus and the prefrontal cortex in the same anesthetized rats subjected to either acute (30 min) or chronic (30 min for 7 days) electrically induced bilateral hindlimb contraction. While CBF in the cortical area representing the hindlimb was assessed from both laser doppler flowmetry (LDF) and changes in p-eNOS levels (p-eNOS), CBF was evaluated only from changes in p-eNOS levels in the hippocampus and the prefrontal cortex. The contribution of increased cardiac output and increased neuronal activity to CBF changes were examined. Stimulation was associated with tachycardia and no change in arterial blood pressure. It increased LDF with a time- and intensity-dependent manner as well as p-eNOS in the area representing the hindlimb. By contrast, p-eNOS was unchanged in the two other regions. The augmentation of LDF was partially reduced by atenolol (a ß1 receptor antagonist) and not reproduced by the administration of dobutamine (a ß1 receptor agonist). Levels of c-fos as a marker of neuronal activation selectively increased in the area representing the hindlimb. In conclusion, electrically induced bilateral hindlimb contraction selectively increased CBF in the cortical area representing the stimulated muscles as a result of neuronal hyperactivity and increased cardiac output. The absence of CBF changes in cognition-related brain regions does not support flow-dependent neuroplasticity in the pro-cognitive effect of electrically induced contraction of a large muscular mass.
脑血流量（CBF）的升高可能有助于定期进行体育锻炼对大脑产生益处。令人惊讶的是，虽然电刺激诱导大块肌肉收缩是一种改善认知的体育锻炼潜在替代方式，但其对CBF的影响仍有待研究。因此，本研究在同一麻醉大鼠中，研究了急性（30分钟）或慢性（每天30分钟，持续7天）电刺激诱导双侧后肢收缩后，代表后肢的皮质区域、海马体和前额叶皮质的CBF情况。代表后肢的皮质区域的CBF通过激光多普勒血流仪（LDF）和磷酸化内皮型一氧化氮合酶（p-eNOS）水平变化进行评估，而海马体和前额叶皮质的CBF仅通过p-eNOS水平变化进行评估。研究了心输出量增加和神经元活动增加对CBF变化的作用。刺激与心动过速相关，动脉血压无变化。它以时间和强度依赖性方式增加了代表后肢区域的LDF以及p-eNOS。相比之下，另外两个区域的p-eNOS没有变化。阿替洛尔（一种β1受体拮抗剂）部分降低了LDF的增加，而多巴酚丁胺（一种β1受体激动剂）给药后未再现这种增加。作为神经元激活标志物的c-fos水平在代表后肢的区域选择性增加。总之，电刺激诱导双侧后肢收缩由于神经元活动亢进和心输出量增加，选择性地增加了代表受刺激肌肉的皮质区域的CBF。认知相关脑区CBF无变化不支持电刺激诱导大块肌肉收缩的促认知作用中血流依赖性神经可塑性。
