Interactions Between Nicotine Addiction and Food Reward

描述（由申请人提供）：戒烟后体重经常增加(2)。对体重增加的恐惧被认为是不戒烟的主要原因(3)，而实际体重增加是复发的主要原因，尤其是在女性中(6)。虽然戒烟后体重增加的原因很复杂(2)，但热量摄入增加被认为是主要原因之一（2,7,8）。就像接触到吸烟的线索会诱发吸烟一样，接触到食物的线索也会诱发进食，即使是在吃饱的动物身上也是如此。热量摄入增加的一种解释是，食物和香烟奖励有共同的神经机制，尼古丁成瘾会导致大脑对吸烟信号编码的变化，也会导致大脑对食物信号编码的变化。这个应用程序的目标是测试这个预测。我们建议使用功能磁共振成像（fMRI）来验证尼古丁成瘾与大脑边缘对食物线索的反应减弱有关的预测，而戒烟会导致大脑边缘对食物线索的反应增强。根据药物成瘾的激励-敏感化理论（13,14），我们还预测食物奖励的神经编码差异是特定于食物线索的激励显著性编码，而不是以对食物接收的感知或神经反应的差异为特征。为了评估这些预测，我们将检查吸烟者、非吸烟者和极度戒断吸烟者对食物气味、同样令人愉快和强烈的花香、食物接收和无味溶液接收的大脑反应。为了补充神经成像数据，我们还计划收集食物奖励的感知和行为测量，包括：1)评估食物和花香的快乐等级，以及食物接收；2)评估受试者将为食物奖励工作的数量；3)即兴消费巧克力饼干。对这些措施的反应将被用作协变量来预测吸烟者、非吸烟者和急性剥夺吸烟者对食物香味的神经反应。如果数据支持我们的预测，那么我们将用它来支持R01应用程序，以测试大脑和行为对食物的反应是否可以用来预测戒烟期间的体重增加。如果大脑反应确实能预测体重增加，那么我们将开发出一种方法来识别有复发风险的个体，这样他们就可以进行进一步的治疗干预。

DESCRIPTION (provided by applicant): Weight gain frequently follows smoking cessation(2). Fear of weight gain is cited as a key reason not to quit(3) and actual weight gain is a primary reason for relapse, especially among women(6). Although the causes of weight gain following smoking cessation are complex(2), increased caloric intake is recognized as one of the primary sources(2,7,8). Just as exposure to smoking cues can induce smoking, exposure to food cues can induce feeding, even in sated animals(9). One explanation for increased caloric intake is that there are common neural mechanisms for food and cigarette reward and that nicotine addiction, which results in changes in brain encoding of smoking cues, also results in changes in brain encoding of food cues. The goal of this application is to test this prediction. We propose to use fMRI to test the prediction that nicotine addiction is associated with a decrease in the limbic response to food cues whereas cessation results in an increase in the limbic response to food cues. In accordance with the incentive-sensitization theory of drug addiction(13,14) we also predict that differences in neural encoding of food reward is specific to incentive salience encoding of food cues and is not characterized by differences in perceptual or neural response to food receipt. To evaluate these predictions we will examine brain response to food odors, equally pleasant and intense floral odors, food receipt, and receipt of a tasteless solution in smokers, non-smokers, and acutely abstinent smokers. To compliment the neuroimaging data we also plan to gather perceptual and behavioral measures of food reward including 1) assessment of hedonic ratings of food and floral odors, and food receipt; 2) assessment of the amount a subject will work for a food reward; and 3) ad lib consumption of chocolate chip cookies. Responses on these measures will then be used as covariates to predict neural response to food aromas in smokers, nonsmokers and acutely deprived smokers. If the data support our predictions then we will use it to support an R01 application to test whether brain and behavioral response to food can be used to predict weight gain during smoking cessation. If brain response does predict weight gain then we will have developed a method to identify individuals at risk for relapse so that they can be targeted for further therapeutic intervention.