Wellcome Centre for Integrative Neuroimaging, FMRIB Centre, Nuffield Department of Clinical Neurosciences (NDCN), John Radcliffe Hospital, Headington, Oxford, United Kingdom; Centre de Recherche en Neurosciences de Lyon, Equipe Trajectoires, Inserm UMR-S 1028, CNRS UMR 5292, Université Lyon 1, Bron, France.
Wellcome Centre for Integrative Neuroimaging, FMRIB Centre, Nuffield Department of Clinical Neurosciences (NDCN), John Radcliffe Hospital, Headington, Oxford, United Kingdom; Turner Institute for Brain and Mental Health, Monash University, Melbourne, Australia.
Neuroimage. 2021 Dec 15;245:118681. doi: 10.1016/j.neuroimage.2021.118681. Epub 2021 Oct 30.
Ageing disrupts the finely tuned excitation/inhibition balance (E:I) across cortex via a natural decline in inhibitory tone (γ-amino butyric acid, GABA), causing functional decrements. However, in young adults, experimentally lowering GABA in sensorimotor cortex enhances a specific domain of sensorimotor function: adaptation memory. Here, we tested the hypothesis that as sensorimotor cortical GABA declines naturally with age, adaptation memory would increase, and the former would explain the latter. Results confirmed this prediction. To probe causality, we used brain stimulation to further lower sensorimotor cortical GABA during adaptation. Across individuals, how stimulation changed memory depended on sensorimotor cortical E:I. In those with low E:I, stimulation increased memory; in those with high E:I stimulation reduced memory. Thus, we identified a form of motor memory that is naturally strengthened by age, depends causally on sensorimotor cortex neurochemistry, and may be a potent target for motor skill preservation strategies in healthy ageing and neurorehabilitation.
衰老是通过抑制性神经递质（γ-氨基丁酸，GABA）自然减少来破坏皮质中精细的兴奋/抑制平衡（E：I），从而导致功能减退。然而，在年轻人中，通过实验降低感觉运动皮层中的 GABA 会增强特定的感觉运动功能：适应记忆。在这里，我们测试了以下假设：随着感觉运动皮质 GABA 随年龄自然下降，适应记忆会增加，而前者将解释后者。结果证实了这一预测。为了探究因果关系，我们在适应过程中使用脑刺激进一步降低感觉运动皮层中的 GABA。在个体之间，刺激如何改变记忆取决于感觉运动皮层的 E：I。在 E：I 较低的个体中，刺激会增加记忆；在 E：I 较高的个体中，刺激会降低记忆。因此，我们确定了一种自然随年龄增强的运动记忆形式，它与感觉运动皮层的神经化学密切相关，并且可能是健康衰老和神经康复中运动技能保存策略的一个有力靶点。
