Changes in microglial development and morphology can be induced by inflammatory conditions and associated with eating or mood disorders, such as hyperphagia or depression. In a previous paper in the minipig model, we showed that maternal Western diet during gestation and lactation decreased hippocampus neurogenesis and food-rewarded cognitive abilities in the progeny. Whether these alterations are concomitant with a central inflammatory process in brain structures involved in learning and memory (hippocampus, HPC), cognitive (prefrontal cortex, PFC), or hedonic (orbitofrontal cortex, OFC) control of food intake is still unknown. In the present study, Yucatan minipigs (Sus scrofa) sows were exposed to two different diets during gestation and lactation (standard, SD N = 7 vs. Western diet, WD N = 9). Iba1 is a calcium-binding protein specifically expressed in microglia in the brain, which plays an important role in the regulation of the microglia function. Iba1 expression was examined by immunohistochemical analyses in the PFC, OFC and HPC of piglets. The density of microglial cells, as well as their morphology, were assessed in order to have an indirect insight of microglial cell activation state possibly in relationship with neuroinflammation. The density of Iba1-positive cells was higher in the PFC but not in the HPC of WD compared to SD piglets (p < 0.001). In the HPC, anterior and dorsolateral PFC, WD piglets had more unipolar cells, contrary to SD that had more multipolar cells (P < 0.0001). Opposite effects were observed in the OFC, with SD presenting more unipolar (P < 0.001) microglial cells compared to WD. We showed here that maternal diet during pregnancy and lactation had significant effects on morphological changes of microglial cells in the offspring, and that these effects differed between the HPC and PFC, suggesting different response mechanisms to the early nutritional environment.

小胶质细胞发育和形态的变化可以由炎症引起，并与进食或情绪失调有关，例如食欲亢进或抑郁。在minipig模型的先前论文中，我们显示了孕期和哺乳期的母体西方饮食降低了子代的海马神经发生和食物奖励的认知能力。这些改变是否与学习和记忆（海马，HPC），认知（前额叶皮层，PFC）或享乐（眶额叶皮层，OFC）所控制的大脑结构的中央炎症过程同时发生尚不清楚。在本研究中，尤卡坦小型猪（Sus scrofa）母猪在妊娠和哺乳期间均接受两种饮食（标准SD N = 7 vs。西方饮食，WD N = 9）。Iba1是钙结合蛋白，在脑小胶质细胞中特异性表达，在调节小胶质细胞功能中起重要作用。通过免疫组织化学分析检查了仔猪的PFC，OFC和HPC中的Iba1表达。评估了小胶质细胞的密度及其形态，以间接了解小胶质细胞的激活状态，可能与神经炎症有关。与SD仔猪相比，WD的PFC中的Iba1阳性细胞密度更高，而WD的HPC中则没有（P <0.001）。在HPC，前外侧和背外侧PFC中，WD仔猪的单极细胞更多，而SD仔猪的多极细胞更多（P<0.0001）。在OFC中观察到相反的作用，与WD相比，SD呈现出更多的单极（P <0.001）小胶质细胞。我们在这里表明，孕期和哺乳期的母亲饮食对后代中小胶质细胞的形态变化具有显着影响，并且这些影响在HPC和PFC之间有所不同，表明对早期营养环境的响应机制不同。