Neuroscience Interdepartmental Program, Ahmanson Lovelace Brain Mapping Center, University of California Los Angeles, 660 Charles E. Young Drive South, Los Angeles, CA, 90095, USA.
Department of Psychology and Neuroscience, The University of North Carolina at Chapel Hill, Chapel Hill, USA.
Mol Autism. 2023 Oct 11;14(1):38. doi: 10.1186/s13229-023-00571-4.
Sensory over-responsivity (SOR) is an impairing sensory processing challenge in autism spectrum disorder (ASD) which shows heterogenous developmental trajectories and appears to improve into adulthood in some but not all autistic individuals. However, the neural mechanisms underlying interindividual differences in these trajectories are currently unknown.
Here, we used functional magnetic resonance imaging (fMRI) to investigate the association between age and neural activity linearly and nonlinearly in response to mildly aversive sensory stimulation as well as how SOR severity moderates this association. Participants included 52 ASD (14F) and 41 (13F) typically developing (TD) youth, aged 8.6-18.0 years.
We found that in pre-teens, ASD children showed widespread activation differences in sensorimotor, frontal and cerebellar regions compared to TD children, while there were fewer differences between ASD and TD teens. In TD youth, older age was associated with less activation in the prefrontal cortex. In contrast, in ASD youth, older age was associated with more engagement of sensory integration and emotion regulation regions. In particular, orbitofrontal and medial prefrontal cortices showed a nonlinear relationship with age in ASD, with an especially steep increase in sensory-evoked neural activity during the mid-to-late teen years. There was also an interaction between age and SOR severity in ASD youth such that these age-related trends were more apparent in youth with higher SOR.
The cross-sectional design limits causal interpretations of the data. Future longitudinal studies will be instrumental in determining how prefrontal engagement and SOR co-develop across adolescence.
Our results suggest that enhanced recruitment of prefrontal regions may underlie age-related decreases in SOR for a subgroup of ASD youth.
感觉过度反应（SOR）是自闭症谱系障碍（ASD）中一种具有损伤性的感觉处理挑战，其表现出异质的发展轨迹，并且在一些但不是所有自闭症个体中似乎会在成年后改善。然而，目前尚不清楚这些轨迹中个体间差异的神经机制。
在这里，我们使用功能磁共振成像（fMRI）来线性和非线性地研究年龄与对轻度厌恶感觉刺激的神经活动之间的关联，以及 SOR 严重程度如何调节这种关联。参与者包括 52 名 ASD（14 名女性）和 41 名（13 名女性）典型发育（TD）青少年，年龄在 8.6-18.0 岁之间。
我们发现，在青少年前阶段，与 TD 儿童相比，ASD 儿童在感觉运动、额叶和小脑区域表现出广泛的激活差异，而 ASD 和 TD 青少年之间的差异较少。在 TD 青少年中，年龄较大与前额叶皮层的激活减少有关。相比之下，在 ASD 青少年中，年龄较大与更多的感觉整合和情绪调节区域的参与有关。特别是，眶额和内侧前额叶皮质在 ASD 中与年龄呈非线性关系，在青少年中期到后期，感觉诱发的神经活动急剧增加。ASD 青少年中还存在年龄和 SOR 严重程度之间的相互作用，即这些与年龄相关的趋势在 SOR 较高的青少年中更为明显。
横断面设计限制了对数据的因果解释。未来的纵向研究将有助于确定前额叶参与和 SOR 如何在青少年时期共同发展。
我们的结果表明，增强前额叶区域的募集可能是 ASD 青少年中与年龄相关的 SOR 减少的基础。
