Graduate Program of Nutrition, Federal University of Pernambuco, Recife, Brazil.
Nantes Université, INRAE, UMR 1280, PhAN, Nantes, France.
Int J Dev Neurosci. 2020 May;80(3):209-219. doi: 10.1002/jdn.10018. Epub 2020 Mar 9.
Early life stress (ELS) has been associated with developmental impairments. Early weaning (EW) is a postnatal stress model consisting of interruption of lactation and maternal care. The 5HT-system has been associated with neurobehavioral modulations promoted by ELS. Thus, the present work aims to investigate the effects of early weaning on feeding behavior and serotonergic system of juvenile male rats. For this, rats were submitted to early (PND15) or natural (PND30) weaning and had the body weight, food intake in circadian phases, and food intake in response to fenfluramine assessed. mRNA expression of serotoninergic receptors (5HT1A and 5HT2C) and transporter (SERT) was assessed in the hypothalamus and brainstem, as well as NPY and POMC mRNA expression in hypothalamus. The results show that early weaning promoted changes in the percentage of weight gain during lactation period and increase in body weight at PND40. It was also observed that EW promoted increase and decrease in food intake in light and dark phase, respectively, and leads to a decreased action of fenfluramine on inhibition of food intake. In addition, early weaning promoted increased NPY and SERT mRNA expression in the hypothalamus and 5HT2C in the brainstem. Together, the data indicate that the stress caused by early weaning impairs the eating behavior of juvenile male rats through hypofunction of the 5HT-system.
早期生活应激（ELS）与发育障碍有关。早期断奶（EW）是一种产后应激模型，包括中断哺乳和母婴分离。5HT 系统与 ELS 促进的神经行为调节有关。因此，本研究旨在探讨早期断奶对幼雄性大鼠摄食行为和 5-羟色胺能系统的影响。为此，将大鼠分为早期（PND15）或自然（PND30）断奶，并评估体重、昼夜节律摄食和芬氟拉明刺激的摄食。在下丘脑和脑干中评估 5-羟色胺能受体（5HT1A 和 5HT2C）和转运体（SERT）的 mRNA 表达，以及下丘脑中 NPY 和 POMC 的 mRNA 表达。结果表明，早期断奶促进了哺乳期体重增加百分比的变化，并增加了 PND40 时的体重。还观察到，EW 分别促进了亮暗相的摄食增加和减少，并导致芬氟拉明抑制摄食的作用减弱。此外，早期断奶促进了下丘脑 NPY 和 SERT mRNA 表达以及脑干 5HT2C 的增加。总之，数据表明，早期断奶引起的应激通过 5HT 系统功能低下损害幼雄性大鼠的摄食行为。
