Puts Nicolaas A J, Wodka Ericka L, Harris Ashley D, Crocetti Deana, Tommerdahl Mark, Mostofsky Stewart H, Edden Richard A E
Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, 600 N Wolfe Street, Baltimore, Maryland, 21287.
F.M. Kirby Center for Functional Brain Imaging, Kennedy Krieger Institute, 707 N Broadway Street, Baltimore, Maryland, 21205.
Autism Res. 2017 Apr;10(4):608-619. doi: 10.1002/aur.1691. Epub 2016 Sep 9.
Abnormal responses to tactile stimuli are a common feature of autism spectrum disorder (ASD). Several lines of evidence suggest that GABAergic function, which has a crucial role in tactile processing, is altered in ASD. In this study, we determine whether in vivo GABA levels are altered in children with ASD, and whether alterations in GABA levels are associated with abnormal tactile function in these children.
GABA-edited magnetic resonance spectroscopy was acquired in 37 children with Autism and 35 typically developing children (TDC) from voxels over primary sensorimotor and occipital cortices. Children performed tactile tasks previously shown to be altered in ASD, linked to inhibitory mechanisms. Detection threshold was measured with- and without the presence of a slowly increasing sub-threshold stimulus. Amplitude discrimination was measured with- and without the presence of an adapting stimulus, and frequency discrimination was measured.
Sensorimotor GABA levels were significantly reduced in children with autism compared to healthy controls. Occipital GABA levels were normal. Sensorimotor GABA levels correlated with dynamic detection threshold as well as with the effect of sub-threshold stimulation. Sensorimotor GABA levels also correlated with amplitude discrimination after adaptation (an effect absent in autism) and frequency discrimination in controls, but not in children with autism.
GABA levels correlate with behavioral measures of inhibition. Children with autism have reduced GABA, associated with abnormalities in tactile performance. We show here that altered in vivo GABA levels might predict abnormal tactile information processing in ASD and that the GABA system may be a future target for therapies. Autism Res 2016. © 2016 International Society for Autism Research, Wiley Periodicals, Inc.
对触觉刺激的异常反应是自闭症谱系障碍（ASD）的一个常见特征。多项证据表明，在触觉处理中起关键作用的γ-氨基丁酸（GABA）能功能在ASD中发生了改变。在本研究中，我们确定ASD儿童体内的GABA水平是否发生改变，以及GABA水平的改变是否与这些儿童的异常触觉功能相关。
对37名自闭症儿童和35名发育正常儿童（TDC）的初级感觉运动皮层和枕叶皮层体素进行GABA编辑磁共振波谱分析。儿童执行先前已证明在ASD中会发生改变且与抑制机制相关的触觉任务。在有和没有缓慢增加的阈下刺激的情况下测量检测阈值。在有和没有适应性刺激的情况下测量幅度辨别，并测量频率辨别。
与健康对照组相比，自闭症儿童的感觉运动GABA水平显著降低。枕叶GABA水平正常。感觉运动GABA水平与动态检测阈值以及阈下刺激的效果相关。感觉运动GABA水平还与适应后的幅度辨别（自闭症中不存在的一种效应）以及对照组中的频率辨别相关，但与自闭症儿童无关。
GABA水平与抑制的行为指标相关。自闭症儿童的GABA水平降低，与触觉表现异常有关。我们在此表明，体内GABA水平的改变可能预示着ASD中异常的触觉信息处理，并且GABA系统可能是未来治疗的一个靶点。《自闭症研究》2016年。©2016国际自闭症研究协会，威利期刊公司。
