The Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, 5290002, Ramat Gan, Israel.
Department of Psychology, Bar-Ilan University, 5290002, Ramat Gan, Israel.
Mol Autism. 2022 Sep 5;13(1):36. doi: 10.1186/s13229-022-00513-6.
In the last decade, accumulative evidence has shown that oxytocin can modulate social perception in typically developed individuals and individuals diagnosed with autism. While several studies show that oxytocin (OT) modulates neural activation in social-related neural regions, the mechanism that underlies OT effects in ASD is not fully known yet. Despite evidence from animal studies on connections between the oxytocinergic system and excitation/inhibition neural balance, the influence of OT on oscillatory responses among individuals with ASD has been rarely examined. To bridge these gaps in knowledge, we investigated the effects of OT on both social and non-social stimuli while focusing on its specific influence on the neural connectivity between three socially related neural regions-the left and right fusiform and the medial frontal cortex.
Twenty-five adolescents with ASD participated in a wall-established social task during a randomized, double-blind placebo-controlled MEG and OT administration study. Our main task was a social-related task that required the identification of social and non-social-related pictures. We hypothesized that OT would modulate the oscillatory connectivity between three pre-selected regions of interest to be more adaptive to social processing. Specifically, we focused on alpha and gamma bands which are known to play an important role in face processing and top-down/bottom-up balance.
Compared to placebo, OT reduced the connectivity between the medial frontal cortex and the fusiform in the low gamma more for social stimuli than for non-social ones, a reduction that was correlated with individuals' performance in the task. Additionally, for both social and non-social stimuli, OT increased the connectivity in the alpha and beta bands.
Sample size was determined based on sample sizes previously reported in MEG in clinical populations, especially OT administration studies in combination with neuroimaging in ASD. We were limited in our capability to recruit for such a study, and as such, the sample size was not based on a priori power analysis. Additionally, we limited our analyses to specific neural bands and regions. To validate the current results, future studies may be needed to explore other parameters using whole-brain approaches in larger samples.
These results suggest that OT influenced social perception by modifying the communication between frontal and posterior regions, an attenuation that potentially impacts both social and non-social early perception. We also show that OT influences differ between top-down and bottom-up processes, depending on the social context. Overall, by showing that OT influences both social-related perception and overall attention during early processing stages, we add new information to the existing understanding of the impact of OT on neural processing in ASD. Furthermore, by highlighting the influence of OT on early perception, we provide new directions for treatments for difficulties in early attentional phases in this population. Trial registration Registered on October 27, 2021-Retrospectively registered, https://clinicaltrials.gov/ct2/show/record/NCT05096676 (details on clinical registration can be found in www.
gov , unique identifier: NCT05096676 ).
在过去的十年中，越来越多的证据表明，催产素可以调节典型发展个体和自闭症个体的社会感知。虽然有几项研究表明催产素（OT）调节与社会相关的神经区域中的神经激活，但自闭症中 OT 作用的机制尚不完全清楚。尽管动物研究有关于催产素能系统与兴奋/抑制神经平衡之间的联系的证据，但 OT 对自闭症个体中的振荡反应的影响很少被研究。为了弥补这些知识上的差距，我们研究了 OT 对社会和非社会刺激的影响，同时重点研究 OT 对三个与社会相关的神经区域（左、右梭状回和内侧额皮质）之间神经连接的特定影响。
25 名自闭症青少年参与了一项在随机、双盲、安慰剂对照的 MEG 和 OT 给药研究中建立的壁式社会任务。我们的主要任务是一项社会相关的任务，要求识别社会和非社会相关的图片。我们假设 OT 将调节三个预先选择的感兴趣区域之间的振荡连接，以使其更适应社会处理。具体来说，我们专注于 alpha 和 gamma 波段，这些波段已知在面部处理和自上而下/自下而上平衡中发挥重要作用。
与安慰剂相比，OT 降低了内侧额皮质与低伽马频段中梭状回之间的连接，对于社会刺激的降低大于非社会刺激，这种降低与个体在任务中的表现相关。此外，对于社会和非社会刺激，OT 增加了 alpha 和 beta 波段的连接。
样本量是根据以前在临床人群中的 MEG 中报告的样本量确定的，特别是在自闭症中结合神经影像学进行 OT 给药的研究。我们在招募方面受到限制，因此样本量不是基于先验功效分析确定的。此外，我们将分析仅限于特定的神经波段和区域。为了验证当前的结果，未来的研究可能需要在更大的样本中使用全脑方法来探索其他参数。
这些结果表明，OT 通过调节额叶和后叶区域之间的通讯来影响社会感知，这种衰减可能会影响社会和非社会的早期感知。我们还表明，OT 影响在自上而下和自下而上的过程之间存在差异，这取决于社会背景。总的来说，通过表明 OT 影响社会相关感知和早期处理阶段的整体注意力，我们为 OT 对自闭症神经处理的影响的现有理解增加了新的信息。此外，通过强调 OT 对早期感知的影响，我们为该人群中早期注意力阶段的困难提供了新的治疗方向。
于 2021 年 10 月 27 日注册-回顾性注册，[www.clinicaltrials.gov/ct2/show/record/NCT05096676（有关临床注册的详细信息可在 www.clinicaltrials.gov 上找到]。
