Manyukhina Viktoriya O, Prokofyev Andrey O, Obukhova Tatiana S, Stroganova Tatiana A, Orekhova Elena V
Center for Neurocognitive Research (MEG Center), Moscow State University of Psychology and Education, Moscow, Russian Federation.
National Research University Higher School of Economics, Moscow, Russian Federation.
Imaging Neurosci (Camb). 2024 Apr 26;2. doi: 10.1162/imag_a_00146. eCollection 2024.
It has been shown that cessation of intensive sensory stimulation is associated with a transient increase in functional inhibition in the sensory cortical areas. However, the electrophysiological correlates of this post-stimulus inhibition in the human brain have not been thoroughly investigated. To investigate post-stimulus inhibition, we analyzed magnetoencephalogram (MEG) recorded at rest and after cessation of visual stimulation of varying intensity (high-contrast gratings drifting at a slow, medium, or high rate) in 25 healthy women aged 18-40 years. We analyzed condition- and intensity-related changes in MEG parameters sensitive to functional inhibition: periodic alpha-beta power, peak alpha frequency (PAF), and 1/f aperiodic slope. We also investigated the association of these parameters with sensory sensitivity and avoidance assessed by a questionnaire. To evaluate the influence of hormonal status on the studied parameters, participants were examined twice, during the follicular and luteal phases of the menstrual cycle (MC). Regardless of the MC phase, increasing drift rate of visual gratings resulted in a proportional increase of post-stimulus posterior alpha-beta power, PAF, and a negative shift of the aperiodic (1/f) slope of the power spectrum in the high-frequency range. Compared to rest, the post-stimulus periods were characterized by higher PAF, more negative 1/f slope in posterior cortical areas, and a widespread increase in beta power. While condition- and drift-rate-dependent modulations of alpha-beta power and 1/f slope were correlated, changes in PAF did not correlate with either of them. A greater intensity-dependent increase in visual alpha-beta power predicted higher subjective sensory sensitivity/avoidance, suggesting stronger regulatory top-down modulation of the visual cortex in individuals with heightened sensitivity. Our results show that several MEG parameters concordantly indicate a post-stimulus enhancement of inhibition that is proportional to the intensity of the preceding visual stimulation. While post-stimulus changes in alpha-beta power and 1/f slope may share some common mechanisms, changes in PAF reflect a distinct aspect of inhibitory regulation. Our results inform potential inhibition-based biomarkers for clinical and translational research.
研究表明，强烈感觉刺激的停止与感觉皮层区域功能抑制的短暂增加有关。然而，人类大脑中这种刺激后抑制的电生理相关性尚未得到充分研究。为了研究刺激后抑制，我们分析了25名年龄在18至40岁的健康女性在静息状态下以及停止不同强度（高对比度光栅以慢、中或高速漂移）视觉刺激后的脑磁图（MEG）。我们分析了对功能抑制敏感的MEG参数中与条件和强度相关的变化：周期性α-β功率、α峰值频率（PAF）和1/f非周期性斜率。我们还通过问卷调查研究了这些参数与感觉敏感性和回避之间的关联。为了评估激素状态对研究参数的影响，在月经周期（MC）的卵泡期和黄体期对参与者进行了两次检查。无论MC阶段如何，视觉光栅漂移率的增加都会导致刺激后枕部α-β功率、PAF成比例增加，以及高频范围内功率谱的非周期性（1/f）斜率向负向偏移。与静息状态相比，刺激后时期的特征是PAF更高、枕部皮层区域的1/f斜率更负，以及β功率普遍增加。虽然α-β功率和1/f斜率的条件依赖性和漂移率依赖性调制是相关的，但PAF的变化与它们两者均不相关。视觉α-β功率更大的强度依赖性增加预示着更高的主观感觉敏感性/回避，表明在敏感性较高的个体中视觉皮层存在更强的自上而下的调节。我们的结果表明，几个MEG参数一致表明刺激后抑制增强，且与先前视觉刺激的强度成比例。虽然刺激后α-β功率和1/f斜率的变化可能有一些共同机制，但PAF的变化反映了抑制调节的一个独特方面。我们的结果为临床和转化研究提供了基于潜在抑制的生物标志物。
