Adolescence has been hypothesized to be a critical period for the development of human association cortex and higher-order cognition. A defining feature of critical period development is a shift in the excitation: inhibition (E/I) balance of neural circuitry, however how changes in E/I may enhance cortical circuit function to support maturational improvements in cognitive capacities is not known. Harnessing ultra-high field 7 T MR spectroscopy and EEG in a large, longitudinal cohort of youth (N = 164, ages 10–32 years old, 347 neuroimaging sessions), we delineate biologically specific associations between age-related changes in excitatory glutamate and inhibitory GABA neurotransmitters and EEG-derived measures of aperiodic neural activity reflective of E/I balance in prefrontal association cortex. Specifically, we find that developmental increases in E/I balance reflected in glutamate:GABA balance are linked to changes in E/I balance assessed by the suppression of prefrontal aperiodic activity, which in turn facilitates robust improvements in working memory. These findings indicate a role for E/I-engendered changes in prefrontal signaling mechanisms in the maturation of cognitive maintenance. More broadly, this multi-modal imaging study provides evidence that human association cortex undergoes physiological changes consistent with critical period plasticity during adolescence.

中文翻译：

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非周期性脑电图和 7T MRSI 证据证明 E/I 平衡的成熟支持青春期工作记忆的发展

青春期被认为是人类联想皮层和高阶认知发展的关键时期。关键期发育的一个决定性特征是神经回路的兴奋：抑制 (E/I) 平衡的变化，但是 E/I 的变化如何增强皮质回路功能以支持认知能力的成熟提高尚不清楚。利用超高场 7 T 磁共振波谱和脑电图对一个大型纵向青年队列（N = 164，年龄 10-32 岁，347 次神经影像学检查），我们描绘了兴奋性谷氨酸和年龄相关变化之间的生物学特异性关联。抑制性 GABA 神经递质和脑电图衍生的非周期性神经活动测量，反映前额叶联合皮层的 E/I 平衡。具体来说，我们发现谷氨酸：GABA 平衡所反映的 E/I 平衡的发育增加与通过抑制前额叶非周期性活动评估的 E/I 平衡的变化有关，这反过来又促进了工作记忆的强劲改善。这些发现表明 E/I 引起的前额叶信号机制变化在认知维持的成熟中发挥着作用。更广泛地说，这项多模态成像研究提供了证据，表明人类关联皮层经历了与青春期关键期可塑性一致的生理变化。