Fedota John R, Stein Elliot A
Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, Maryland.
Ann N Y Acad Sci. 2015 Sep;1349(1):64-82. doi: 10.1111/nyas.12882.
Given conceptual frameworks of addiction as a disease of intercommunicating brain networks, examinations of network interactions may provide a holistic characterization of addiction-related dysfunction. One such methodological approach is the examination of resting-state functional connectivity, which quantifies correlations in low-frequency fluctuations of the blood oxygen level-dependent magnetic resonance imaging signal between disparate brain regions in the absence of task performance. Here, evidence of differentiated effects of chronic nicotine exposure, which reduces the efficiency of network communication across the brain, and acute nicotine exposure, which increases connectivity within specific limbic circuits, is discussed. Several large-scale resting networks, including the salience, default, and executive control networks, have also been implicated in nicotine addiction. The dynamics of connectivity changes among and between these large-scale networks during nicotine withdrawal and satiety provide a heuristic framework with which to characterize the neurobiological mechanism of addiction. The ability to simultaneously quantify effects of both chronic (trait) and acute (state) nicotine exposure provides a platform to develop a neuroimaging-based addiction biomarker. While such development remains in its early stages, evidence of coherent modulations in resting-state functional connectivity at various stages of nicotine addiction suggests potential network interactions on which to focus future addiction biomarker development.
鉴于成瘾是一种涉及大脑网络相互交流的疾病这一概念框架，对网络相互作用的研究可能会提供成瘾相关功能障碍的整体特征描述。一种这样的方法是检查静息态功能连接，它量化了在没有任务执行的情况下不同脑区之间血氧水平依赖性功能磁共振成像信号低频波动的相关性。在此，将讨论慢性尼古丁暴露（会降低全脑网络通信效率）和急性尼古丁暴露（会增加特定边缘回路内的连接性）的不同影响的证据。包括突显网络、默认网络和执行控制网络在内的几个大规模静息网络也与尼古丁成瘾有关。在尼古丁戒断和饱腹感期间，这些大规模网络之间以及内部连接性变化的动态过程提供了一个启发式框架，用以描述成瘾的神经生物学机制。同时量化慢性（特质）和急性（状态）尼古丁暴露影响的能力为开发基于神经成像的成瘾生物标志物提供了一个平台。虽然这种开发仍处于早期阶段，但在尼古丁成瘾各个阶段静息态功能连接的连贯调制证据表明，存在潜在的网络相互作用，可作为未来成瘾生物标志物开发的重点。
