Monk Christopher S, Peltier Scott J, Wiggins Jillian Lee, Weng Shih-Jen, Carrasco Melisa, Risi Susan, Lord Catherine
Department of Psychology, University of Michigan, 530 Church St., Ann Arbor MI 48109, USA.
Neuroimage. 2009 Aug 15;47(2):764-72. doi: 10.1016/j.neuroimage.2009.04.069. Epub 2009 May 3.
Autism spectrum disorders (ASD) impact social functioning and communication, and individuals with these disorders often have restrictive and repetitive behaviors. Accumulating data indicate that ASD is associated with alterations of neural circuitry. Functional MRI (FMRI) studies have focused on connectivity in the context of psychological tasks. However, even in the absence of a task, the brain exhibits a high degree of functional connectivity, known as intrinsic or resting connectivity. Notably, the default network, which includes the posterior cingulate cortex, retro-splenial, lateral parietal cortex/angular gyrus, medial prefrontal cortex, superior frontal gyrus, temporal lobe, and parahippocampal gyrus, is strongly active when there is no task. Altered intrinsic connectivity within the default network may underlie offline processing that may actuate ASD impairments. Using FMRI, we sought to evaluate intrinsic connectivity within the default network in ASD. Relative to controls, the ASD group showed weaker connectivity between the posterior cingulate cortex and superior frontal gyrus and stronger connectivity between the posterior cingulate cortex and both the right temporal lobe and right parahippocampal gyrus. Moreover, poorer social functioning in the ASD group was correlated with weaker connectivity between the posterior cingulate cortex and the superior frontal gyrus. In addition, more severe restricted and repetitive behaviors in ASD were correlated with stronger connectivity between the posterior cingulate cortex and right parahippocampal gyrus. These findings indicate that ASD subjects show altered intrinsic connectivity within the default network, and connectivity between these structures is associated with specific ASD symptoms.
自闭症谱系障碍（ASD）会影响社交功能和沟通，患有这些障碍的个体通常会有局限和重复的行为。越来越多的数据表明，ASD与神经回路的改变有关。功能磁共振成像（fMRI）研究主要关注心理任务背景下的连接性。然而，即使在没有任务的情况下，大脑也表现出高度的功能连接性，即所谓的内在或静息连接性。值得注意的是，默认网络包括后扣带回皮质、压后皮质、外侧顶叶皮质/角回、内侧前额叶皮质、额上回、颞叶和海马旁回，在没有任务时会强烈激活。默认网络内的内在连接性改变可能是导致离线处理异常的基础，而这种异常可能引发ASD障碍。我们使用fMRI来评估ASD患者默认网络内的内在连接性。与对照组相比，ASD组在后扣带回皮质和额上回之间的连接性较弱，而后扣带回皮质与右侧颞叶和右侧海马旁回之间的连接性较强。此外，ASD组较差的社交功能与后扣带回皮质和额上回之间较弱的连接性相关。另外，ASD中更严重的局限和重复行为与后扣带回皮质和右侧海马旁回之间较强的连接性相关。这些发现表明，ASD患者在默认网络内表现出内在连接性改变，这些结构之间的连接性与特定的ASD症状相关。
