Lee Jenna R, Tapia Melissa A, Nelson Jane R, Moore Justin M, Gereau Graydon B, Childs Tom E, Vieira-Potter Victoria J, Booth Frank W, Will Matthew J
Interdisciplinary Neuroscience Program, University of Missouri, Columbia, MO, USA.
Department of Psychological Sciences, University of Missouri, Columbia, MO, USA.
Behav Brain Res. 2019 Feb 1;359:95-103. doi: 10.1016/j.bbr.2018.10.018. Epub 2018 Oct 27.
Considering the current obesity epidemic is due in large part to an energy imbalance, it is crucial to explore biological mechanisms that mediate palatable high energy food intake and physical activity behavior levels. Previous research demonstrates a unique sex dependent influence of physical activity on diet preference, specifically changes in palatable high-fat diet intake. Therefore, factors of motivation may be underlying the differential effect of physical activity in male and female rats on their diet preference. The present study extends this hypothesis by assessing diet preference in male and female Wistar rats selectively bred for high (HVR) and low (LVR) levels of voluntary wheel running distances. HVR and LVR rats were housed under either sedentary (SED) or voluntary wheel running access (RUN) conditions for the duration of the study. Following a 1 week acclimation period to these conditions, standard chow was replaced with concurrent ad libitum access to a choice of 3 pelleted diets (high-fat, high-sucrose, and high-corn starch); all 3 were provided in the home cage. Body weight, running distance, and intake of each diet was measured daily. At the conclusion of the 4 week diet preference test, animals were sacrificed and ventral striatum tissue was collected for later analysis. Results demonstrated intake patterns of diets were uniquely influenced by physical activity dependent on both the sex and the selectively bred line of rat. In addition, reward related ventral striatal mRNA expression was also dependent on both the sex and the selectively bred line of rat. Overall, the pattern of both behavioral and mRNA results suggest that voluntary wheel running behavior differentially mediates palatable diet consumption in males and females. Considering the pervasive abundance of both physical inactivity, combined with over-consumption of energy dense palatable diets, it is vital to understand the nature of these behavioral interactions.
鉴于当前肥胖流行在很大程度上归因于能量失衡，探索介导美味高能量食物摄入和身体活动行为水平的生物学机制至关重要。先前的研究表明身体活动对饮食偏好有独特的性别依赖性影响，特别是在美味高脂肪饮食摄入方面的变化。因此，动机因素可能是雄性和雌性大鼠身体活动对其饮食偏好产生差异影响的潜在原因。本研究通过评估选择性培育的高（HVR）和低（LVR）自愿轮跑距离的雄性和雌性Wistar大鼠的饮食偏好来扩展这一假设。在研究期间，将HVR和LVR大鼠置于久坐不动（SED）或自愿轮跑条件（RUN）下饲养。在对这些条件进行1周的适应期后，将标准食物换成同时随意选择3种颗粒饲料（高脂肪、高蔗糖和高玉米淀粉）；所有3种饲料都放在饲养笼中。每天测量体重、跑步距离和每种饲料的摄入量。在为期4周的饮食偏好测试结束时，处死动物并收集腹侧纹状体组织以供后续分析。结果表明，饮食摄入模式受到身体活动的独特影响，这取决于大鼠的性别和选择性培育品系。此外，与奖赏相关的腹侧纹状体mRNA表达也取决于大鼠的性别和选择性培育品系。总体而言，行为和mRNA结果的模式表明，自愿轮跑行为在雄性和雌性中对美味饮食消费的介导作用存在差异。鉴于普遍存在身体不活动以及能量密集型美味饮食的过度消费，了解这些行为相互作用的本质至关重要。
