Laboratory of Stress Neurobiology, Institute of Physiology, Faculty of Sciences, Universidad de Valparaíso, Valparaíso, Chile.
School of Psychology, Faculty of Social Sciences, Universidad de las Américas, Viña del Mar, Chile.
J Neuroendocrinol. 2018 Jul;30(7):e12609. doi: 10.1111/jne.12609.
The foetal brain is highly susceptible to stress in late pregnancy, with lifelong effects of stress on physiology and behaviour. The present study aimed to determine the physiological and behavioural effects of prenatal stress during the prepubertal period of female and male rats. We subjected pregnant Sprague-Dawley rats to a restraint stress protocol from gestational day 14 to 21, a critical period for foetal brain susceptibility to stress effects. Male and female offspring were subsequently assessed at postnatal day 24 for anxiety- and depressive-like behaviours, as well as spontaneous social interaction. We also assessed maternal behaviours and 2 stress markers: basal vs acute-evoked stress levels of serum corticosterone and body weight gain. Prenatal stress did not affect the maternal behaviour, whereas both female and male offspring had higher body weight gain. On the other hand, lower levels of corticosterone after acute stress stimulation, as well as anxiety- and depressive-like behaviours, were only evident in stressed males compared to control males. These results suggest that prenatal stress induced sex-specific effects on hypothalamic-pituitary-adrenal (HPA) axis activity and on behaviour during prepuberty. The HPA axis of prenatally stressed male rats was less active compared to control males, and they were also more anxious and experienced depressive-like behaviours. These results are useful with respect to studying the neurobiological basis of childhood depression at a preclinical level.
胎儿大脑在妊娠晚期极易受到压力的影响，压力对生理和行为会产生终身影响。本研究旨在确定孕期应激对雌性和雄性大鼠青春期前阶段的生理和行为影响。我们对怀孕的 Sprague-Dawley 大鼠进行了从妊娠第 14 天到 21 天的束缚应激方案，这是胎儿大脑对应激影响敏感的关键时期。随后，在出生后第 24 天评估雄性和雌性后代的焦虑和抑郁样行为以及自发社交互动。我们还评估了母性行为和 2 个应激标志物：基础与急性诱发的血清皮质酮水平和体重增加。孕期应激并未影响母性行为，而雌性和雄性后代的体重增加均较高。另一方面，与对照组雄性相比，应激雄性的急性应激刺激后皮质酮水平较低，且表现出焦虑和抑郁样行为。这些结果表明，孕期应激对青春期前的下丘脑-垂体-肾上腺（HPA）轴活动和行为产生了性别特异性影响。与对照组雄性相比，孕期应激雄性的 HPA 轴活性较低，且他们也更焦虑和出现抑郁样行为。这些结果对于在临床前水平研究儿童抑郁症的神经生物学基础很有用。
