School of Psychology, Wales Institute of Cognitive Neuroscience, Bangor University, Bangor, Gwynedd, UK.
Cereb Cortex. 2011 Jun;21(6):1408-15. doi: 10.1093/cercor/bhq220. Epub 2010 Nov 2.
The course to alcohol dependence often starts with a preclinical period of heavy drinking. The present article reports functional magnetic resonance imaging data showing that even this pattern of alcohol consumption is associated with maladaptive neural responses to alcohol and other stimuli. When participants were confronted with visual cues related to alcohol, heavy drinkers showed amplified blood oxygen level-dependent signal responses in specific emotional areas (insular cortex) and in parts of the brain's reward circuitry (ventral striatum). This neuronal amplification was not present in light drinkers. Crucially, at the same time heavy drinkers showed reduced responses in frontal areas to pictures related to higher order life goals and in the cingulate cortex to appetitive food stimuli, suggesting that they have difficulty finding alternative, socially desirable goals. Using discriminant function analysis, we demonstrate that the combination of alcohol-related overactivation and underactivation to alternative goals allows heavy and light drinkers to be differentiated with a high degree of precision. Our findings highlight the diagnostic value of functional brain mapping of cue reactivity. Imaging measures may help to identify addictive dispositions in preclinical stages and to clarify the mechanisms that underlie the development and maintenance of alcohol dependence.
酒精依赖的形成过程通常始于临床前的大量饮酒期。本文报告的功能磁共振成像数据显示，即使是这种饮酒模式也与对酒精和其他刺激的适应不良的神经反应有关。当参与者面对与酒精相关的视觉提示时，重度饮酒者在特定的情绪区域（脑岛）和大脑奖励回路的某些部位（腹侧纹状体）显示出增强的血氧水平依赖信号反应。这种神经元放大在轻度饮酒者中并不存在。至关重要的是，与此同时，重度饮酒者在与更高阶生活目标相关的图片以及与开胃食物刺激相关的扣带皮层中显示出对前额区域的反应减少，这表明他们难以找到替代的、社会期望的目标。通过判别函数分析，我们证明，与替代目标相关的过度激活和激活不足的组合可以以很高的精度区分重度和轻度饮酒者。我们的研究结果强调了线索反应功能脑映射的诊断价值。影像学测量可能有助于在临床前阶段识别成瘾倾向，并阐明导致酒精依赖发展和维持的机制。
