Department of Radiology, University of Calgary, Calgary, AB, Canada.
Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
Sci Rep. 2021 Jan 12;11(1):722. doi: 10.1038/s41598-020-80530-8.
The inhibitory neurotransmitter γ-Aminobutyric acid (GABA) plays a crucial role in cortical development. Therefore, characterizing changes in GABA levels during development has important implications for the study of healthy development and developmental disorders. Brain GABA levels can be measured non-invasively using GABA-edited magnetic resonance spectroscopy (MRS). However, the most commonly used editing technique to measure GABA results in contamination of the GABA signal with macromolecules (MM). Therefore, GABA measured using this technique is often referred to as GABA+ . While few in number, previous studies have shown GABA+ levels increase with age during development. However, these studies are unable to specify whether it is specifically GABA that is increasing or, instead, if levels of MM increase. In this study, we use a GABA-editing technique specifically designed to suppress the MM signal (MM-supp GABA). We find no relationship between MM-supp GABA and age in healthy children aged 7-14 years. These findings suggest that the relationship between GABA+ and age is driven by changes in MM levels, not by changes in GABA levels. Moreover, these findings highlight the importance of accounting for MM levels in MRS quantification.
抑制性神经递质γ-氨基丁酸（GABA）在皮质发育中起着至关重要的作用。因此，描述发育过程中 GABA 水平的变化对于研究健康发育和发育障碍具有重要意义。脑 GABA 水平可以使用 GABA 编辑磁共振波谱（MRS）进行非侵入性测量。然而，最常用于测量 GABA 的编辑技术会导致 GABA 信号与大分子（MM）污染。因此，使用该技术测量的 GABA 通常被称为 GABA+。尽管数量很少，但先前的研究表明，在发育过程中，GABA+水平随年龄增长而增加。然而，这些研究无法确定增加的是特定的 GABA，还是 MM 的水平增加了。在这项研究中，我们使用了一种专门设计用于抑制 MM 信号的 GABA 编辑技术（MM-supp GABA）。我们在 7-14 岁的健康儿童中未发现 MM-supp GABA 与年龄之间存在关系。这些发现表明，GABA+与年龄之间的关系是由 MM 水平的变化驱动的，而不是 GABA 水平的变化。此外，这些发现强调了在 MRS 定量中考虑 MM 水平的重要性。
