Leon Zoela, Shah Krishna, Bailey Lauren S, Karkhanis Anushree N, Sirohi Sunil
Laboratory of Endocrine and Neuropsychiatric Disorders, Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, United States.
Department of Psychology, Behavioral Neuroscience Program, Center for Developmental and Behavioral Neuroscience, Binghamton University-SUNY Binghamton, Binghamton, NY, United States.
Front Behav Neurosci. 2021 Oct 20;15:725856. doi: 10.3389/fnbeh.2021.725856. eCollection 2021.
While a bidirectional positive link between palatable food intake and alcohol drinking has been suggested, several rodents studies report reduced alcohol drinking following palatable diets exposure. These studies utilized purified rodents' diets high in sugar/fat; however, the effects of hyper-palatable food (HPF) rich in fat and sugar on alcohol drinking remain unclear. Furthermore, neural substrates involved in HPF-mediated changes in alcohol consumption are poorly understood. Therefore, the present study evaluated the effects of patterned feeding of a hyper-palatable food (Oreo cookies) on alcohol drinking as well as dopamine (DA) and serotonin (5-HT) content in rat's mesocorticolimbic (medial-prefrontal cortex, orbitofrontal cortex, amygdala, and nucleus accumbens) circuitry. Male Long Evans rats received 8-weeks of intermittent (Mon, Tue, Wed) Oreo cookies access, which induced a patterned feeding, in which rats in the Oreo group overconsumed calories on HPF days whereas underconsumption was observed on chow only (Thu, Fri) days. Following HPF exposure, alcohol consumption was evaluated while patterned feeding continued. Alcohol intake in the Oreo group was significantly lower as compared to the chow controls. However, alcohol intake in the Oreo group increased to the levels seen in the group receiving chow following the suspension of patterned HPF feeding. Finally, DA levels in the nucleus accumbens were significantly greater, whereas its metabolite (DOPAC) levels were lower in the Oreo group compared to the chow controls. Surprisingly, 5-HT levels remained unaltered in all tested brain areas. Together, these data suggest that HPF-associated increased DA availability and reduced DA turnover within mesocorticolimbic circuitry may regulate alcohol drinking following patterned HPF feeding.
虽然有人提出美味食物摄入与饮酒之间存在双向正向联系，但多项啮齿动物研究报告称，在接触美味饮食后饮酒量会减少。这些研究使用了高糖/高脂肪的纯化啮齿动物饮食；然而，富含脂肪和糖的超美味食物（HPF）对饮酒的影响仍不清楚。此外，人们对参与HPF介导的饮酒变化的神经基质了解甚少。因此，本研究评估了超美味食物（奥利奥饼干）的定时喂养对大鼠饮酒以及中脑边缘系统（内侧前额叶皮质、眶额皮质、杏仁核和伏隔核）回路中多巴胺（DA）和5-羟色胺（5-HT）含量的影响。雄性长 Evans 大鼠接受了为期8周的间歇性（周一、周二、周三）奥利奥饼干喂食，这导致了一种定时喂养模式，即奥利奥组的大鼠在食用HPF的日子里热量摄入过多，而在仅食用普通食物（周四、周五）的日子里热量摄入不足。在接触HPF后，在持续定时喂养的同时评估饮酒量。与普通食物对照组相比，奥利奥组的酒精摄入量显著降低。然而，在暂停HPF定时喂养后，奥利奥组的酒精摄入量增加到了食用普通食物组的水平。最后，与普通食物对照组相比，奥利奥组伏隔核中的DA水平显著更高，而其代谢物（DOPAC）水平更低。令人惊讶的是，所有测试脑区的5-HT水平均未改变。总之，这些数据表明，HPF相关的中脑边缘系统回路中DA可用性增加和DA周转减少可能会在HPF定时喂养后调节饮酒量。
