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人类初级体感皮层和运动皮层中刺激驱动的高频血氧水平依赖振荡的可检测性及皮层深度依赖性

Detectability and cortical depth dependence of stimulus-driven high-frequency BOLD oscillations in the human primary somatosensory and motor cortex.

作者信息

Hodono Shota, Polimeni Jonathan R, Reutens David, Cloos Martijn A

机构信息

Donders Centre for Cognitive Neuroimaging, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands.

Centre for Advanced Imaging, The University of Queensland, Brisbane, QLD, Australia.

出版信息

Imaging Neurosci (Camb). 2025 Jan 13;3. doi: 10.1162/imag_a_00427. eCollection 2025.

Abstract

In functional magnetic resonance imaging (fMRI), neural activity is inferred from the associated hemodynamic response. However, the degree to which hemodynamics can track dynamic changes in neuronal activity, and thus the ultimate temporal resolution of fMRI, remains unknown. To evaluate the detectability of stimulus-driven high-frequency blood oxygenation level dependent (BOLD) signal oscillations in functionally and vascularly distinct cerebral cortical areas, stimuli up to 0.5 Hz were used to evoke activation in the primary somatosensory and motor cortex. Despite their functional and vascular differences, a similar frequency dependence was observed in both cortical areas. We then proceeded to investigate these signals at different levels of the cortical vascular hierarchy, using cortical depth as a proxy. We observed that, above 0.33 Hz, the BOLD response amplitude decreased faster with increasing frequency near the pial surface than in the parenchyma, suggesting that, in addition to exhibiting high spatial specificity, parenchymal signals-accessible with high spatial resolution imaging-also attenuate less rapidly when the stimulus frequency is increased. In addition, as the stimulus frequency increased, we observed larger relative phase differences in the BOLD oscillations across cortical depths. When averaged across depths, these signals can thus interfere destructively, suggesting that high spatial resolutions can avoid this phase cancellation and thereby aid in the detection of rapid BOLD oscillations.

摘要

在功能磁共振成像(fMRI)中,神经活动是通过相关的血液动力学反应推断出来的。然而,血液动力学能够追踪神经元活动动态变化的程度,以及fMRI的最终时间分辨率,仍然未知。为了评估在功能和血管方面不同的大脑皮质区域中,刺激驱动的高频血氧水平依赖(BOLD)信号振荡的可检测性,使用高达0.5Hz的刺激来诱发初级体感皮层和运动皮层的激活。尽管它们在功能和血管方面存在差异,但在两个皮质区域都观察到了类似的频率依赖性。然后,我们以皮质深度为代表,在皮质血管层次结构的不同水平上研究这些信号。我们观察到,在0.33Hz以上,软脑膜表面附近的BOLD反应幅度随频率增加的下降速度比实质内更快,这表明,除了表现出高空间特异性外,通过高空间分辨率成像可获取的实质信号在刺激频率增加时衰减也较慢。此外,随着刺激频率的增加,我们在整个皮质深度的BOLD振荡中观察到更大的相对相位差。当在不同深度进行平均时,这些信号可能会产生相消干涉,这表明高空间分辨率可以避免这种相位抵消,从而有助于检测快速的BOLD振荡。

https://cdn.ncbi.nlm.nih.gov/pmc/blobs/dc4d/12319743/3a66f0517a05/imag_a_00427_fig1.jpg

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