Deters Justin R, Fietsam Alexandra C, Workman Craig D, Rudroff Thorsten
Department of Health and Human Physiology, University of Iowa, Iowa City, IA 52242, USA.
Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA.
Brain Sci. 2022 Apr 15;12(4):506. doi: 10.3390/brainsci12040506.
Transcranial direct current stimulation (tDCS) research has shown great outcome variability in motor performance tasks, with one possible source being sex differences. The goal of this study was to evaluate the effects of estrogen levels on leg muscle fatigability during a fatigue task (FT) after 4 mA tDCS over the left motor cortex (M1). Ten young, healthy eumenorrheic women received 4 mA anodal active or sham stimulation over the left M1 during periods of high and low estrogen levels. A fatigue index (FI) was calculated to quantify fatigability, and the electromyography (EMG) of the knee extensors and flexors was recorded during the FT. The findings showed that tDCS applied during high estrogen levels resulted in greater leg muscle fatigability. Furthermore, a significant increase in EMG activity of the right knee extensors was observed during periods of active stimulation, independent of estrogen level. These results suggest that estrogen levels should be considered in tDCS studies with young healthy women.
经颅直流电刺激（tDCS）研究表明，在运动性能任务中结果存在很大差异，一个可能的原因是性别差异。本研究的目的是评估在对左侧运动皮层（M1）施加4毫安tDCS后，雌激素水平对疲劳任务（FT）期间腿部肌肉疲劳性的影响。十名年轻、健康、月经正常的女性在雌激素水平高和低的时期，接受了对左侧M1的4毫安阳极有效刺激或假刺激。计算疲劳指数（FI）以量化疲劳性，并在FT期间记录膝伸肌和屈肌的肌电图（EMG）。研究结果表明，在高雌激素水平期间施加tDCS会导致更大的腿部肌肉疲劳性。此外，在有效刺激期间，观察到右膝伸肌的EMG活动显著增加，且与雌激素水平无关。这些结果表明，在针对年轻健康女性的tDCS研究中应考虑雌激素水平。
