西安电子科技大学--生命科学技术学院
 
当前位置: 主页 > 研究成果 > 代表性成果 >

11、布拉德-威利(PWS)肥胖模型中,杏仁核对下丘脑的异常驱动研

更新时间:2015-08-01 14:16 点击:
  

 普拉德-威利综合症(PWS)是一种引起深度贪食和早期儿童肥胖的遗传疾病。

以往报道都是通过图片刺激来研究PWS患者与正常人对于食物与非食物图片刺激的大脑功能差异,但PWS患者在没有食物刺激时仍暴饮暴食,无法停止。于是,我们假设PWS患者与正常人相比,杏仁核对下丘脑有异常的驱动作用力,从而破坏下丘脑能量平衡调节,导致他们暴饮暴食。本研究针对21位PWS患者和18位正常被试的静息态数据进行分析,首先得到两组被试静息态下大脑功能差异区(图1,2所示),然后利用Granger分析发现左右杏仁核(AMY)对下丘脑(Hy)存在异常驱动以及前扣带(ACC)和内侧前额叶皮质(MPFC)对右侧杏仁核也存在异常驱动作用(图3所示)。
此外,还从静息态网络群的角度分析了PWS和正常人的数据,发现了PWS患者在缺省模式网络(DMN),Core网络,运动感觉网络(Motor sensory)和前额叶区域(Prefrontal Lobe)四个网络的功能连接方面存在着差异(图4)。
 
The neurobiological drive for overeating implicated in Prader-Willi syndrome
Prader-Willi syndrome (PWS) is a genetic imprinting disorder characterized mainly by hyperphagia and early childhood obesity. Previous fMRI studies examined the activation of eating-related neural circuits in PWS patients with or without exposures to food cues and found an excessive eating motivation and a reduced inhibitory control of cognitive processing of food. However, the effective connectivity between various brain areas or neural circuitry critically implicated in both the biological and behavioral control of overeating in PWS is largely unexplored. The current study combined resting-state fMRI and Granger causality analysis (GCA) techniques to investigate interactive causal influences among key neural pathways underlying overeating in PWS. We first defined the regions of interest (ROIs) that demonstrated significant alterations of the baseline brain activity levels in children with PWS (n=21) as compared to that of their normal siblings controls (n=18), and then carried out GCA to characterize the region-to-region interactions among these ROIs. Our data revealed significantly enhanced causal influences from the amygdala to the hypothalamus and from both the medial prefrontal cortex and anterior cingulate cortex to the amygdala in patients with PWS (P< 0.001). These alterations offer new explanations for hypothalamic regulation of homeostatic energy intake and impairment in inhibitory control circuit. The deficits in these dual aspects may jointly contribute to the extreme hyperphagia in PWS. This study provides both a new methodological and a neurobiological perspective to aid in a better understanding of neural mechanisms underlying obesity in the general public.
 
                   
                  
------分隔线----------------------------
西安电子科技大学 生命科学技术学院 版权所有 2009-2016
电子工程学院网络信息中心制作维护  管理员信箱 xidianlife@163.com