Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital Boston, MA, USA ; Harvard Medical School Boston, MA, USA.
Front Hum Neurosci. 2013 Aug 6;7:444. doi: 10.3389/fnhum.2013.00444. eCollection 2013.
Autism spectrum disorder (ASD) has been called a "developmental disconnection syndrome," however the majority of the research examining connectivity in ASD has been conducted exclusively with older children and adults. Yet, prior ASD research suggests that perturbations in neurodevelopmental trajectories begin as early as the first year of life. Prospective longitudinal studies of infants at risk for ASD may provide a window into the emergence of these aberrant patterns of connectivity. The current study employed functional connectivity near-infrared spectroscopy (NIRS) in order to examine the development of intra- and inter-hemispheric functional connectivity in high- and low-risk infants across the first year of life.
NIRS data were collected from 27 infants at high risk for autism (HRA) and 37 low-risk comparison (LRC) infants who contributed a total of 116 data sets at 3-, 6-, 9-, and 12-months. At each time point, HRA and LRC groups were matched on age, sex, head circumference, and Mullen Scales of Early Learning scores. Regions of interest (ROI) were selected from anterior and posterior locations of each hemisphere. The average time course for each ROI was calculated and correlations for each ROI pair were computed. Differences in functional connectivity were examined in a cross-sectional manner.
At 3-months, HRA infants showed increased overall functional connectivity compared to LRC infants. This was the result of increased connectivity for intra- and inter-hemispheric ROI pairs. No significant differences were found between HRA and LRC infants at 6- and 9-months. However, by 12-months, HRA infants showed decreased connectivity relative to LRC infants.
Our preliminary results suggest that atypical functional connectivity may exist within the first year of life in HRA infants, providing support to the growing body of evidence that aberrant patterns of connectivity may be a potential endophenotype for ASD.
自闭症谱系障碍（ASD）被称为“发育性脱节综合征”，然而，大多数研究自闭症连接的研究仅在年龄较大的儿童和成人中进行。然而，先前的 ASD 研究表明，神经发育轨迹的干扰早在生命的第一年就开始了。对有 ASD 风险的婴儿进行前瞻性纵向研究可能为研究这些异常连接模式的出现提供一个窗口。本研究采用近红外光谱功能连接（NIRS）技术，以研究高危自闭症（HRA）和低危对照组（LRC）婴儿在生命第一年的大脑半球内和半球间功能连接的发育情况。
NIRS 数据来自 27 名自闭症高风险婴儿（HRA）和 37 名低风险对照组（LRC）婴儿，共收集了 116 组数据，分别在 3、6、9 和 12 个月时进行。在每个时间点，HRA 和 LRC 组在年龄、性别、头围和穆伦早期学习量表分数方面进行匹配。选择每个半球的前、后位置的感兴趣区域（ROI）。计算每个 ROI 的平均时间历程，并计算每个 ROI 对的相关性。以横截面方式检查功能连接的差异。
在 3 个月时，与 LRC 婴儿相比，HRA 婴儿的整体功能连接增强。这是由于半球内和半球间 ROI 对的连接增加所致。在 6 个月和 9 个月时，HRA 和 LRC 婴儿之间没有发现显著差异。然而，到 12 个月时，与 LRC 婴儿相比，HRA 婴儿的连接减少。
我们的初步结果表明，HRA 婴儿在生命的第一年可能存在异常的功能连接，这为越来越多的证据提供了支持，即异常的连接模式可能是 ASD 的一个潜在的内表型。
