Dela Cruz J A D, Coke T, Karagiorgis T, Sampson C, Icaza-Cukali D, Kest K, Ranaldi R, Bodnar R J
Neuropsychology Doctoral Sub-Program, The Graduate Center, City University of New York, USA; School of Mental Health and Neuroscience, Maastricht University, USA.
Department of Psychology, Queens College, City University of New York, USA.
Brain Res Bull. 2015 Feb;111:9-19. doi: 10.1016/j.brainresbull.2014.11.002. Epub 2014 Nov 24.
Overconsumption of nutrients high in fats and sugars can lead to obesity. Previous studies indicate that sugar or fat consumption activate individual brain sites using Fos-like immunoreactivity (FLI). Sugars and fats also elicit conditioned flavor preferences (CFP) that are differentially mediated by flavor-flavor (orosensory: f/f) and flavor-nutrient (post-ingestive: f/n) processes. Dopamine (DA) signaling in the medial prefrontal cortex (mPFC), the amygdala (AMY) and the nucleus accumbens (NAc), has been implicated in acquisition and expression of fat- and sugar-CFP. The present study examined the effects of acute consumption of fat (corn oil: f/f and f/n), glucose (f/f and f/n), fructose, (f/f only), saccharin, xanthan gum or water upon simultaneous FLI activation of DA mesotelencephalic nuclei (ventral tegmental area (VTA)) and projections (infralimbic and prelimbic mPFC, basolateral and central-cortico-medial AMY, core and shell of NAc as well as the dorsal striatum). Consumption of corn oil solutions, isocaloric to glucose and fructose, significantly increased FLI in all sites except for the NAc shell. Glucose intake significantly increased FLI in both AMY areas, dorsal striatum and NAc core, but not in either mPFC area, VTA or Nac shell. Correspondingly, fructose intake significantly increased FLI in the both AMY areas, the infralimbic mPFC and dorsal striatum, but not the prelimbic mPFC, VTA or either NAc area. Saccharin and xanthan gum intake failed to activate FLI relative to water. When significant FLI activation occurred, highly positive relationships were observed among sites, supporting the idea of activation of a distributed brain network mediating sugar and fat intake.
过量摄入富含脂肪和糖的营养物质会导致肥胖。先前的研究表明，糖或脂肪的摄入会通过Fos样免疫反应（FLI）激活个体脑区。糖和脂肪还会引发条件性味觉偏好（CFP），其分别由味觉-味觉（口腔感觉：f/f）和味觉-营养物质（摄入后：f/n）过程介导。内侧前额叶皮质（mPFC）、杏仁核（AMY）和伏隔核（NAc）中的多巴胺（DA）信号传导与脂肪和糖诱导的CFP的获得和表达有关。本研究检测了急性摄入脂肪（玉米油：f/f和f/n）、葡萄糖（f/f和f/n）、果糖（仅f/f）、糖精、黄原胶或水对DA中脑核团（腹侧被盖区（VTA））及其投射（边缘下和边缘前mPFC、基底外侧和中央皮质内侧AMY、NAc的核心和壳以及背侧纹状体）同时FLI激活的影响。摄入与葡萄糖和果糖等热量的玉米油溶液，除NAc壳外，显著增加了所有脑区的FLI。摄入葡萄糖显著增加了两个AMY区域、背侧纹状体和NAc核心的FLI，但在mPFC的任何一个区域、VTA或NAc壳中均未增加。相应地，摄入果糖显著增加了两个AMY区域、边缘下mPFC和背侧纹状体的FLI，但在边缘前mPFC、VTA或任何一个NAc区域中未增加。相对于水，摄入糖精和黄原胶未能激活FLI。当出现显著的FLI激活时，各脑区之间观察到高度正相关，支持激活一个介导糖和脂肪摄入的分布式脑网络的观点。
