López-Taboada Isabel, Sal-Sarria Saúl, Vallejo Guillermo, Coto-Montes Ana, Conejo Nélida M, González-Pardo Héctor
Laboratory of Neuroscience, Department of Psychology, Faculty of Psychology, University of Oviedo, Plaza Feijoo s/n, 33003, Oviedo, Spain; Institute of Neurosciences of the Principality of Asturias (INEUROPA), Oviedo, Spain; Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Av. del Hospital Universitario s/n, 33011 Oviedo, Spain.
Laboratory of Neuroscience, Department of Psychology, Faculty of Psychology, University of Oviedo, Plaza Feijoo s/n, 33003, Oviedo, Spain; Institute of Neurosciences of the Principality of Asturias (INEUROPA), Oviedo, Spain.
Physiol Behav. 2022 Dec 1;257:113969. doi: 10.1016/j.physbeh.2022.113969. Epub 2022 Sep 28.
Prolonged daily intake of Western-type diet rich in saturated fats and sugars, and exposure to early life stress have been independently linked to impaired neurodevelopment and behaviour in animal models. However, sex-specific effects of both environmental factors combined on spatial learning and memory, behavioural flexibility, and brain oxidative capacity have still not been addressed. The current study aimed to evaluate the impact of maternal and postnatal exposure to a high-fat and high-sugar diet (HFS), and exposure to early life stress by maternal separation in adult male and female Wistar rats. For this purpose, spatial learning and memory and behavioural flexibility were evaluated in the Morris water maze, and regional brain oxidative capacity and oxidative stress levels were measured in the hippocampus and medial prefrontal cortex. Spatial memory, regional brain oxidative metabolism, and levels of oxidative stress differed between females and males, suggesting sexual dimorphism in the effects of a HFS diet and early life stress. Males fed the HFS diet performed better than all other experimental groups independently of early life stress exposure. However, behavioural flexibility evaluated in the spatial reversal leaning task was impaired in males fed the HFS diet. In addition, exposure to maternal separation or the HFS diet increased the metabolic capacity of the prefrontal cortex and dorsal hippocampus in males and females. Levels of oxidative stress measured in the latter brain regions were also increased in groups fed the HFS diet, but maternal separation seemed to dampen regional brain oxidative stress levels. Therefore, these results suggest a compensatory effect resulting from the interaction between prolonged exposure to a HFS diet and early life stress.
长期每日摄入富含饱和脂肪和糖的西式饮食，以及早年经历压力，在动物模型中已被分别证明与神经发育受损和行为异常有关。然而，这两种环境因素共同作用对空间学习与记忆、行为灵活性以及大脑氧化能力的性别特异性影响仍未得到研究。本研究旨在评估成年雄性和雌性Wistar大鼠在母体孕期及产后暴露于高脂高糖饮食（HFS），以及通过母体分离经历早年压力的影响。为此，在莫里斯水迷宫中评估空间学习与记忆以及行为灵活性，并测量海马体和内侧前额叶皮质的区域脑氧化能力和氧化应激水平。雌性和雄性大鼠在空间记忆、区域脑氧化代谢以及氧化应激水平上存在差异，这表明HFS饮食和早年压力的影响存在性别二态性。喂食HFS饮食的雄性大鼠表现优于所有其他实验组，且不受早年压力暴露的影响。然而，在空间反转学习任务中评估的行为灵活性在喂食HFS饮食的雄性大鼠中受损。此外，经历母体分离或喂食HFS饮食会增加雄性和雌性大鼠前额叶皮质和背侧海马体的代谢能力。喂食HFS饮食的组中，在后脑区域测量的氧化应激水平也有所增加，但母体分离似乎会降低区域脑氧化应激水平。因此，这些结果表明长期暴露于HFS饮食和早年压力之间的相互作用产生了一种补偿效应。
