Department of Biology, Morgan State University, 1700 East Cold Spring Lane, Baltimore, MD 21251, USA.
Dev Psychobiol. 2013 Apr;55(3):283-93. doi: 10.1002/dev.21027. Epub 2012 Apr 5.
Early life stress has been linked to the etiology of mental health disorders. Rodent models of neonatal maternal separation stress frequently have been used to explore the long-term effects of early stress on changes in affective and cognitive behaviors. However, most current paradigms risk metabolic deprivation, due to prolonged periods of pup removal from the dam. We have developed a new paradigm in Balb/CByJ mice, that combines very brief periods of maternal separation with temperature stress to avoid the confound of nutritional deficiencies. We have also included a within-litter control group of pups that are not removed from the dam. The present experiments provide an initial behavioral characterization of this new model. We show that neonatally stressed mice display increased anxiety and aggression along with increased locomotion but decreased exploratory behavior. In contrast, littermate controls show increased exploration of novelty, compared to age-matched, colony-reared controls. Behavioral changes in our briefly stressed mice substantially concur with the existing literature, except that we were unable to observe any cognitive deficits in our paradigm. However, we show that within litter control pups also sustain behavioral changes suggesting complex and long-lasting interactions between different environmental factors in early postnatal life.
早期生活压力与心理健康障碍的病因有关。新生期母体分离应激的啮齿动物模型经常被用来探索早期应激对情感和认知行为变化的长期影响。然而,由于幼仔与母体分离时间延长,大多数当前的范式存在代谢剥夺的风险。我们在 Balb/CByJ 小鼠中开发了一种新的范式,该范式将短暂的母体分离与温度应激相结合,以避免营养缺乏的混杂。我们还包括了一组未从母体中取出的同窝幼仔作为对照。本实验对该新模型进行了初步的行为特征描述。我们发现,新生期应激的小鼠表现出焦虑和攻击性增加,同时运动增加,但探索行为减少。相比之下,与同龄、群体饲养的对照相比,同窝对照的幼仔对新奇事物的探索增加。我们短暂应激的小鼠的行为变化与现有文献基本一致,但我们无法在我们的范式中观察到任何认知缺陷。然而,我们发现同窝对照的幼仔也会持续发生行为变化,这表明在新生后早期,不同环境因素之间存在复杂而持久的相互作用。