2022-11-10 ペンシルベニア州立大学(PennState)
研究者らは、脳イメージングにつきもののノイズを除去し、呼吸が神経活動を制御している場所をピンポイントで特定するために、マルチモーダル技術を同時に使用しました。
麻酔下の安静状態のネズミの脳波をfMRIでスキャンすることで、研究者達は、呼吸に関与する脳領域のネットワークを明らかにしました。
fMRIと同時に、研究者達は、神経系の電気的性質と信号を測定する神経電気生理学を使用して、呼吸と、帯状皮質(感情反応と調節に関連する大脳半球中央の脳領域)の神経活動をリンクさせている。fMRIと電気生理を同時に使用することで、研究者はデータ収集中に、動作や二酸化炭素の呼気など、神経に関連しないfMRI信号の変化を突き止めることができた。
<関連情報>
- https://www.psu.edu/news/engineering/story/breathing-may-measurably-modulate-neural-responses-across-brain-study-finds/
- https://elifesciences.org/articles/81555
呼吸に関連した安静時fMRIネットワークの神経基盤の解明 Neural underpinning of a respiration-associated resting-state fMRI network
Wenyu Tu,Nanyin Zhang
eLife Published:Oct 20, 2022
DOI:https://doi.org/10.7554/eLife.81555
Abstract
Respiration can induce motion and CO2 fluctuation during resting-state fMRI (rsfMRI) scans, which will lead to non-neural artifacts in the rsfMRI signal. In the meantime, as a crucial physiologic process, respiration can directly drive neural activity change in the brain, and may thereby modulate the rsfMRI signal. Nonetheless, this potential neural component in the respiration–fMRI relationship is largely unexplored. To elucidate this issue, here we simultaneously recorded the electrophysiology, rsfMRI, and respiration signals in rats. Our data show that respiration is indeed associated with neural activity changes, evidenced by a phase-locking relationship between slow respiration variations and the gamma-band power of the electrophysiological signal recorded in the anterior cingulate cortex. Intriguingly, slow respiration variations are also linked to a characteristic rsfMRI network, which is mediated by gamma-band neural activity. In addition, this respiration-related brain network disappears when brain-wide neural activity is silenced at an isoelectrical state, while the respiration is maintained, further confirming the necessary role of neural activity in this network. Taken together, this study identifies a respiration-related brain network underpinned by neural activity, which represents a novel component in the respiration–rsfMRI relationship that is distinct from respiration-related rsfMRI artifacts. It opens a new avenue for investigating the interactions between respiration, neural activity, and resting-state brain networks in both healthy and diseased conditions.
