Portal glucose influences the sensory, cortical and reward systems in rats
Portal glucose influences the sensory, cortical and reward systems in rats
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DOI：
10.1111/ejn.12354
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发表时间：
2013-11-01
影响因子：
3.4
通讯作者：
Mithieux, Gilles
中科院分区：
文献类型：
--
作者：
Delaere, Fabien;Akaoka, Hideo;Mithieux, Gilles
肝门区葡萄糖的检测是一种简单但关键的外周线索，启动神经信号，最终导致广泛的代谢和行为反应，如减少食物摄入，更严格地控制葡萄糖稳态，或出现食物偏好。这一信号被认为是高蛋白饮食的中介作用，而不是高脂肪/高糖饮食。然而，来自肝门区的信号的中心靶点在很大程度上仍然没有文献记载。使用免疫组织化学对雄性大鼠的大脑，我们在这里表明，门静脉葡萄糖增加c-Fos表达在脑干，在下丘脑（特别是在神经元表达前阿黑皮素），也在嗅觉和其他边缘系统和皮质区，包括那些功能上涉及奖励（实验1）。在类似的吸收后的条件下，高蛋白饮食诱导下丘脑和颗粒细胞的主要嗅球类似的效果，而高脂肪/高糖饮食实际上减少了皮质层的c-Fos的基础表达。两种饮食也减少了杏仁核和味觉区表达c-Fos的神经元的数量（实验2）。总之，这些研究结果表明，由门静脉葡萄糖传感引发的外周信号可能会影响行为适应，例如通过包括嗅觉通路，中央杏仁核，杏仁核和眶额皮质在内的网络的食物偏好，除了饱腹感和主要涉及下丘脑反应的代谢效应。
The detection of glucose in the hepatoportal area is a simple but crucial peripheral cue initiating a nervous signal that ultimately leads to a wide array of metabolic and behavioural responses, such as decreased food intake, tighter control of glucose homeostasis, or appearance of food preference. This signal has been suggested to mediate the effects of high-protein diets, as opposed to high-fat/high-sucrose diets. Nevertheless, the central targets of the signal originating from the hepatoportal area remain largely undocumented. Using immunohistochemistry on the brain of male rats, we show here that portal glucose increases c-Fos expression in the brainstem, in the hypothalamus (in particular in neurons expressing pro-opiomelanocortin) and also in olfactory and other limbic and cortical areas, including those functionally implicated in reward (Experiment 1). In similar postabsorptive conditions, a high-protein diet induced similar effects in the hypothalamus and the granular cells of the main olfactory bulb, whereas the high-fat/high-sucrose diet actually reduced the basal expression of c-Fos in cortical layers. Both diets also decreased the number of neurons expressing c-Fos in the amygdala and gustatory areas (Experiment 2). Altogether, these findings suggest that the peripheral signal primed by portal glucose sensing may influence behavioural adaptation such as food preference via a network including the olfactory pathway, central amygdala, nucleus accumbens and orbitofrontal cortex, in addition to satiety and metabolic effects primarily implicating the hypothalamic response.