- 期刊
預設模式網絡的核磁共振頻譜GABA濃度調控大腦的功能網絡中心性
The GABA Level of the Magnetic Resonance Spectroscopy in Default Mode Network Modulate the Brain Functional Network Centrality
摘要
γ-氨基丁酸（gamma-aminobutyric acid, GABA）是大腦中主要的抑制性神經傳導物質，可以影響大腦神經元而間接在功能磁振造影中使血氧濃度相依對比（blood oxygen label dependent, BOLD）的信號改變，所以BOLD 信號的變化與大腦神經活動以及神經傳導物質息息相關。大腦在休息狀態下，神經活動也仍在進行，目前大腦的活化區域主要在後扣帶皮層（posterior cingulate cortex, PCC）、楔前葉（precuneus, PCu）、內側額葉皮質（medial frontal）和下頂葉（inferior parietal）等區域。這些區域被定義為預設模式網絡（default mode network, DMN），但當我們大腦在進行其他任務導向的認知活動時，DMN 的神經元活動也會被壓抑減少其活化。在本研究中，我們結合靜息態功能磁共振成像（resting-state functional magnetic resonance imaging, rsfMRI）和先進的核磁共振頻譜技術（magnetic resonance spectroscopy, MRS），顯示中的後扣帶皮層區域（PCC/PCu）內GABA 濃度變化與大腦網絡中心性有關。較高網絡中心性有助於大腦網絡中的有效信息流動。後扣帶皮層區域是DMN 的關鍵組成部分，後扣帶皮層區域中的高濃度γ-氨基丁酸抑制DMN的神經與內部思想活動，使得神經活動從內部重新分配到需高注意力資源到的高網絡中心性區域以應付即將到來的外部刺激。
並列摘要
Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the brain, which can affect the brain neurons, and indirectly on the signal changes in the functional magnetic resonance imaging using oxygen concentration label dependent (BOLD). So, BOLD signal changes and brain nerve activity and neurotransmitter are closely related. In resting-state, the activation of the brain is mainly in the posterior cingulate cortex (PCC), preculeus (PCu), medial frontal, parietal and other areas. These regions are defined as the default mode network (DMN). In this study, we combined with resting-state functional magnetic resonance imaging (rsfMRI) and advanced magnetic resonance spectroscopy (MRS), demonstrate that changes in the concentration of γ-aminobutyric acid in the posterior cortical region (PCC/PCu) are related to the network centrality of the brain. Higher network centrality contributes to the flow of effective information in the brain network. The posterior cingulate cortical region is a key component of the default mode network. The high concentration of gamma-aminobutyric acid in the cingulate cortical region inhibits the neural and internal thought activities of the default mode network, resulting in the redistribution of neural activity from within focus resources to the high network centrality area to cope with the upcoming external stimulus.