Effects of expectancy and abstinence on the neural response to smoking cues in cigarette smokers: An fMRI study
Effects of expectancy and abstinence on the neural response to smoking cues in cigarette smokers: An fMRI study
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DOI：
10.1038/sj.npp.1301075
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发表时间：
2006-12-01
影响因子：
7.6
通讯作者：
Dagher, Alain
中科院分区：
文献类型：
--
作者：
McBride, Dharma;Barrett, Sean P.;Dagher, Alain
与吸毒相关的线索可以引发成瘾者的复发，寻求药物和渴望。行为学研究表明，药物的可获得性和戒断会影响个体对药物线索的反应。此外，主观渴望在线索诱导的复吸中的重要性受到质疑，并提出了一种替代模型，根据该模型，药物线索独立于渴望触发习惯性药物寻求行为。我们使用功能性磁共振成像来比较20名健康吸烟者对吸烟和对照录像带的大脑反应，同时改变他们对吸烟和戒烟水平的期望。对香烟线索的神经反应受到预期的强烈调制，在较小程度上，禁欲。对于那些希望在扫描后立即吸烟的人来说，吸烟暗示会激活与觉醒、注意力和认知控制有关的大脑区域。然而，当受试者知道他们将不被允许吸烟4小时，几乎没有大脑激活响应吸烟线索，尽管同等水平的渴望报告。在背外侧前额叶皮层，神经反应是渴望和期望的函数。丘脑-扣带回连接被认为是唤醒的一个指标，在预期中比非预期中更大。我们的研究结果证实了期望在药物提示的神经反应中的重要性，并支持了这些提示作用于涉及唤醒和注意力的大脑区域的理论。
Cues associated with drug taking can trigger relapse, drug seeking, and craving in addicted individuals. Behavioral studies suggest that drug availability and withdrawal can affect the individual response to drug cues. Moreover, the importance of subjective craving in cue-induced relapse has been questioned and an alternative model put forward according to which drug cues trigger habitual drug-seeking behaviors independently of craving. We used functional magnetic resonance imaging to compare the brain response to smoking and control videotapes in 20 healthy smokers, while varying their expectancy to smoke and abstinence levels. The neural response to cigarette cues was strongly modulated by expectancy and, to a lesser extent, abstinence. In people expecting to smoke immediately after the scan, smoking cues activated brain areas implicated in arousal, attention, and cognitive control. However, when subjects knew they would not be allowed to smoke for 4 h, there was almost no brain activation in response to smoking cues, despite equivalent reported levels of craving. In the dorsolateral prefrontal cortex, the neural response was a function of both craving and expectancy. Thalamo-cingulate connectivity, thought to be an index of arousal, was greater during expectancy than nonexpectancy. Our findings confirm the importance of expectancy in the neural response to drug cues, and lend support to the theory that these cues act on brain areas involved in arousal and attention.