The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China.
The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, University of Electronic Science and Technology of China, Chengdu, China.
Neuroimage. 2021 Feb 15;227:117668. doi: 10.1016/j.neuroimage.2020.117668. Epub 2020 Dec 24.
The neuropeptide oxytocin is a key modulator of social-emotional behavior and its intranasal administration can influence the functional connectivity of brain networks involved in the control of attention, emotion and reward reported in humans. However, no studies have systematically investigated the effects of oxytocin on dynamic or directional aspects of functional connectivity. The present study employed a novel computational framework to investigate these latter aspects in 15 oxytocin-sensitive regions using data from randomized placebo-controlled between-subject resting state functional MRI studies incorporating 200 healthy subjects. In order to characterize the temporal dynamics, the 'temporal state' was defined as a temporal segment of the whole functional MRI signal which exhibited a similar functional interaction pattern among brain regions of interest. Results showed that while no significant effects of oxytocin were found on brain temporal state related characteristics (including temporal state switching frequency, probability of transitions between neighboring states, and averaged dwell time on each state) oxytocin extensively (n = 54 links) modulated effective connectivity among the 15 regions. The effects of oxytocin were primarily characterized by increased effective connectivity both between and within emotion, reward, salience, attention and social cognition processing networks and their interactions with the default mode network. Top-down control over emotional processing regions such as the amygdala was particularly affected. Oxytocin also increased effective homotopic interhemispheric connectivity in almost all these regions. Additionally, the effects of oxytocin on effective connectivity were sex-dependent, being more extensive in males. Overall, these findings suggest that modulatory effects of oxytocin on both within- and between-network interactions may underlie its functional influence on social-emotional behaviors, although in a sex-dependent manner. These findings may be of particular relevance to potential therapeutic use of oxytocin in psychiatric disorders associated with social dysfunction, such as autism spectrum disorder and schizophrenia, where directionality of treatment effects on causal interactions between networks may be of key importance .
神经肽催产素是调节社会情感行为的关键调节剂，其鼻腔给药可影响人类报告的注意力、情绪和奖励控制相关脑网络的功能连接。然而，目前尚无研究系统地研究催产素对功能连接的动态或方向方面的影响。本研究采用一种新的计算框架，使用来自 200 名健康受试者的随机安慰剂对照的基于个体的静息状态功能磁共振成像研究的数据，在 15 个催产素敏感区域中研究了这些方面。为了描述时间动态，“时间状态”被定义为整个功能磁共振成像信号的时间片段，该片段表现出感兴趣脑区之间相似的功能相互作用模式。结果表明，虽然催产素对大脑时间状态相关特征（包括时间状态切换频率、相邻状态之间转换的概率以及每个状态的平均停留时间）没有显著影响，但催产素广泛（n=54 个链接）调节了 15 个区域之间的有效连接。催产素的作用主要表现为情绪、奖励、突显、注意力和社会认知处理网络之间以及与默认模式网络之间的有效连接增加，它们的相互作用也增加了。情绪处理区域（如杏仁核）的自上而下控制受到特别影响。催产素还增加了几乎所有这些区域的有效同型半球间连接。此外，催产素对有效连接的影响具有性别依赖性，在男性中更为广泛。总体而言，这些发现表明，催产素对网络内和网络间相互作用的调节作用可能是其对社会情感行为的功能影响的基础，尽管其作用具有性别依赖性。这些发现对于潜在的催产素在与社会功能障碍相关的精神障碍（如自闭症谱系障碍和精神分裂症）中的治疗应用可能具有特别重要的意义，因为治疗效果对网络之间因果相互作用的方向性可能至关重要。
