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本文基于静息态功能磁共振成像研究18名健康男性大学生志愿者在服用盐酸哌甲酯药物后大脑默认网络的效应连接变化。应用动态因果模型方法分析比较在服用安慰剂和盐酸哌甲酯药物两种条件下静息态默认网络的效应连接的区别。静息态的动态因果模型分析以文献研究提供的网络模型为先验基础,将低频波段信号(0.01~0.08 Hz)作为默认网络的驱动输入,再根据盐酸哌甲酯药物对节点间不同连接的调节作用设计32种动态因果可能性模型,最终通过拟合分析和贝叶斯模型选择得到最优模型及模型参数。结果表明,在静息条件下默认网络的内侧前额叶到后扣带回、两侧顶下小叶到内侧前额叶以及右侧顶下小叶到后扣带回的效应连接分别表现为促进状态,而左侧顶下小叶到后扣带回却表现为抑制连接。进一步地,根据盐酸哌甲酯药物与安慰剂条件的连接参数的配对统计比较发现,盐酸哌甲酯显著调节右侧顶下小叶到内侧前额叶皮质的连接(t=2.724,P=0.016),使其由弱促进状态转变为抑制状态,但对其它连接无显著影响。本研究结果表明,盐酸哌甲酯药物对正常志愿者大脑静息态默认网络的效应连接具有显著的调制作用。
This study was based on resting state functional magnetic resonance imaging of 18 healthy male college students taking methylphenidate drug brain network after the default changes in the effect of the connection. A dynamic causal model approach was used to analyze the differences in the effector junctions between the resting net state network and placebo and methylphenidate hydrochloride drugs under both conditions. Based on the network model provided by the literature study, the dynamic causal model of rest state is taken as the priori basis. The signal of low frequency band (0.01 ~ 0.08 Hz) is used as the input of the default network. Then, And 32 kinds of dynamic causality possibility models were designed and adjusted. Finally, the optimal model and model parameters were obtained through fitting analysis and Bayesian model selection. The results show that the efferent connections of the medial prefrontal to the anterior cingulate gyrus, the apical lobule to the medial prefrontal lobe, and the apical parietal lobule to the posterior cingulum of the default network, respectively, appear to be facultative states under resting conditions Left lobes to the posterior cingulate gyrus appears to inhibit the connection. Further, based on the paired statistical comparison of the ligation parameters of the methylphenidate hydrochloride and placebo conditions, it was found that methylphenidate significantly modulated the connection of the right superior parietal lobule to the medial prefrontal cortex (t = 2.724, P = 0.016) Make it change from the state of weak promotion to the state of inhibition, but have no significant effect on other connections. The results of this study show that methylphenidate hydrochloride has a significant modulatory effect on the effector junctions of the resting network in normal volunteers.