Qiu Ying-Wei, Jiang Gui-Hua, Ma Xiao-Fen, Su Huan-Huan, Lv Xiao-Fei, Zhuo Fu-Zhen
Department of Medical Imaging, Guangdong No.2 Provincial People's Hospital, China.
Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Program, Duke-National University of Singapore Graduate Medical School, Singapore.
Addict Biol. 2017 Jul;22(4):1057-1067. doi: 10.1111/adb.12387. Epub 2016 Mar 9.
Models of heroin addiction emphasize the role of disrupted frontostriatal circuitry supporting cognitive control processes. However, heroin addiction-related alterations in functional and structural interactions among brain regions, especially between the cerebral hemispheres, are rarely examined directly. Resting-state functional magnetic resonance imaging (fMRI) approaches, which reveal patterns of coherent spontaneous fluctuations in the fMRI signal, offer a means to quantify directly functional interactions between the hemispheres. The corpus callosum (CC), which connects homologous regions of the cortex, is the major conduit for information transfer between the cerebral hemispheres and represents a structural connectivity index between hemispheres. We compared interhemispheric voxel-mirrored homotopic connectivity (VMHC) and CC volume between 45 heroin dependent-individuals (HDIs) and 35 non-addict individuals. We observed significant reduction of VMHC in a number of regions, particularly the striatum/limbic system regions, and significant decrease in splenium and genu sub-regions of CC in HDI. Importantly, within HDI, VMHC in the dorsal lateral prefrontal cortex (DLPFC) correlated with genu CC volume, VMHC in the putamen, VMHC in the DLPFC and genu CC volume and splenium CC volume were negatively correlated with heroin duration and impulsivity traits. Further analyses demonstrated that impairment of VMHC of bilateral DLPFC partially mediated the association between genu CC volumes decreased and increased impulsivity in HDI. Our results reveal a substantial impairment of interhemispheric coordination in the HDI. Further, interhemispheric connectivity correlated with the duration of heroin abuse and higher impulsivity behavior in HDI. Our findings provide insight into a heroin addicts' related pathophysiology and reinforce an integrative view of the interhemispheric cerebral functional and structural organization.
海洛因成瘾模型强调了破坏支持认知控制过程的额纹状体回路的作用。然而，很少直接研究与海洛因成瘾相关的大脑区域之间，特别是大脑半球之间功能和结构相互作用的改变。静息态功能磁共振成像（fMRI）方法揭示了fMRI信号中连贯的自发波动模式，提供了一种直接量化半球间功能相互作用的手段。胼胝体（CC）连接皮质的同源区域，是大脑半球之间信息传递的主要通道，代表半球间的结构连接指数。我们比较了45名海洛因依赖个体（HDI）和35名非成瘾个体的半球间体素镜像同伦连接（VMHC）和CC体积。我们观察到多个区域的VMHC显著降低，特别是纹状体/边缘系统区域，并且HDI中CC的压部和膝部亚区域显著减少。重要的是，在HDI中，背外侧前额叶皮质（DLPFC）中的VMHC与膝部CC体积相关，壳核中的VMHC、DLPFC中的VMHC以及膝部CC体积和压部CC体积与海洛因使用时间和冲动特质呈负相关。进一步分析表明，双侧DLPFC的VMHC损伤部分介导了HDI中膝部CC体积减少与冲动性增加之间的关联。我们的结果揭示了HDI中半球间协调的实质性损伤。此外，半球间连接与海洛因滥用的持续时间以及HDI中较高的冲动行为相关。我们的发现为海洛因成瘾者相关的病理生理学提供了见解，并强化了对半球间大脑功能和结构组织的综合观点。
