Brain GABA Levels Are Associated with Inhibitory Control Deficits in Older Adults
Brain GABA Levels Are Associated with Inhibitory Control Deficits in Older Adults
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DOI：
10.1523/jneurosci.0760-18.2018
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发表时间：
2018-09-05
影响因子：
5.3
通讯作者：
Swinnen, Stephan P.
中科院分区：
文献类型：
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作者：
Hermans, Lize;Leunissen, Inge;Swinnen, Stephan P.
健康老龄化伴随着运动抑制缺陷，其涉及停止优势运动反应的较慢过程（即，反应性抑制）而不是预期停止的能力减弱（即，前摄抑制）。一些研究表明，有效的运动抑制与GABA能功能有关。由于GABA系统中与年龄相关的改变也有报道，因此运动抑制障碍可能与介导运动抑制的皮质-皮质下网络中的GABA能改变有关。30名年轻人（平均年龄，23.2岁;年龄范围，18-34岁; 14名男性）和29名老年人（平均年龄，67.5岁;年龄范围，60-74岁; 13名男性）执行了具有不同水平停止信号概率的停止信号任务。用磁共振波谱（MRS）测量右侧下额叶皮质、前辅助运动区（pre-SMA）、左侧感觉运动皮质、双侧纹状体和枕叶皮质的GABA（+）水平。我们发现，老年人的反应性抑制比年轻人更差，如更长的停止信号反应时间（SSRTs）所示。没有观察到组间差异的积极抑制，因为两组减缓他们的反应，以类似的程度增加停止信号的概率。MRS结果显示，与年轻人相比，老年人的组织校正GABA（+）水平平均较低。此外，SMA前GABA（+）水平较低的老年人在停止时较慢（即，更长的SSRT）。这些发现表明GABA系统在反应性抑制缺陷中的作用。
Healthy aging is accompanied by motor inhibition deficits that involve a slower process of stopping a prepotent motor response (i.e., reactive inhibition) rather than a diminished ability to anticipate stopping (i.e., proactive inhibition). Some studies suggest that efficient motor inhibition is related to GABAergic function. Since age-related alterations in the GABA system have also been reported, motor inhibition impairments might be linked to GABAergic alterations in the cortico-subcortical network that mediates motor inhibition. Thirty young human adults (mean age, 23.2 years; age range, 18-34 years; 14 men) and 29 older human adults (mean age, 67.5 years; age range, 60-74 years; 13 men) performed a stop-signal task with varying levels of stop-signal probability. GABA (+) levels were measured with magnetic resonance spectroscopy (MRS) in right inferior frontal cortex, pre-supplementary motor area (pre-SMA), left sensorimotor cortex, bilateral striatum, and occipital cortex. We found that reactive inhibition was worse in older adults compared with young adults, as indicated by longer stop-signal reaction times (SSRTs). No group differences in proactive inhibition were observed as both groups slowed down their response to a similar degree with increasing stop-signal probability. The MRS results showed that tissue-corrected GABA (+) levels were on average lower in older as compared with young adults. Moreover, older adults with lower GABA (+) levels in the pre-SMA were slower at stopping (i.e., had longer SSRTs). These findings suggest a role for the GABA system in reactive inhibition deficits.