Toward isolating reward changes in diet-induced obesity: A demand analysis
Toward isolating reward changes in diet-induced obesity: A demand analysis
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DOI：
10.1016/j.physbeh.2019.112729
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发表时间：
2020-01-01
影响因子：
2.9
通讯作者：
Beckmann, Joshua S.
中科院分区：
文献类型：
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作者：
Batten, Seth R.;Hicks, Kayla B.;Beckmann, Joshua S.
虽然众所周知激素和代谢因素会影响肥胖，但最近的证据表明，肥胖可能也受到奖励敏感性变化的影响，类似于其他“奖励病理学”，如物质使用障碍。目前的研究试图通过描述饮食诱导的肥胖症（DIO）临床前模型中对热量（蔗糖）和非热量（糖精）补充剂的经济需求，分离饮食诱导的肥胖症发作后可能发生的奖励变化。我们利用经济需求分析来测量大鼠对蔗糖和糖精替代品的基线需求强度（Q（0））和需求弹性（α）。在收集基线测量数据后，将大鼠随机分配至高脂肪（HF）饮食或低脂肪（LF）对照饮食。饮食暴露8周后，根据HF饮食暴露8周后的体重将HF大鼠分为肥胖抵抗（OR）组和肥胖倾向（OP）组。重新评估了每一种生物的DIO后需求数据。在基线时，与糖精相比，大鼠对蔗糖的需求强度更高，弹性更低。经过8周的高脂饮食，OP大鼠有显着更大的体重增加和较低的需求弹性的蔗糖和糖精和较高的需求强度的糖精。蔗糖和糖精弹性的变化表明，DIO诱导的食物相关行为的变化与奖励过程的变化有关。糖精的需求强度的变化表明，需求强度，作为一个衡量“设定点”，是没有直接联系到代谢过程。目前的研究表明，微观经济学理论和需求分析能够隔离与热量和非热量摄入有关的饮食引起的奖励变化的独立方面。
Although hormonal and metabolic factors are well known to influence obesity, recent evidence suggests that obesity may be influenced also by changes in reward sensitivity akin to that seen in other 'reward pathologies', like substance use disorders. The current study sought to isolate changes in reward that may occur after the onset of diet-induced obesity by characterizing the economic demand for caloric (sucrose) and non-caloric (saccharin) reinforcers in a preclinical model of diet-induced obesity (DIO). We utilized economic demand analysis to measure baseline demand intensity (Q(0)) and demand elasticity (alpha) for sucrose and saccharin reinforcers in rats. After baseline measures were collected, rats were assigned randomly to a high-fat (HF) diet or low-fat (LF) control diet. After 8-weeks of diet exposure, HF rats were divided into obesity-resistant (OR) or obesity-prone (OP) groups based on weight after the 8-week HF diet exposure. Post-DIO demand data for each reinforcer were reassessed. At baseline, rats had higher demand intensity and lower elasticity for sucrose compared to saccharin. After 8-weeks of the high-fat diet, OP rats had significantly greater weight gain and lower demand elasticity for sucrose and saccharin and higher demand intensity for saccharin. The changes in sucrose and saccharin elasticity suggest that DIO-induced changes in food-related behavior are associated with changes in reward processes. The changes in demand intensity for saccharin suggest that demand intensity, as a measure of 'set point', is not directly linked to metabolic processes. The current study shows that microeconomic theory and demand analysis is able to isolate independent aspects of diet-induced reward changes related to caloric and non-caloric reinforcers.