Department of Biomedical Sciences, Tufts University Cummings School of Veterinary Medicine, North Grafton, MA 01536, USA.
Horm Behav. 2013 Sep;64(4):634-41. doi: 10.1016/j.yhbeh.2013.08.011. Epub 2013 Sep 1.
Exposure to early life stress is a predictor of mental health disorders, and two common forms of early life stress are social conflict and impaired maternal care, which are predominant features of postpartum mood disorders. Exposure of lactating female rats to a novel male intruder involves robust social conflict and induces deficits in maternal care towards the F1 offspring. This exposure is an early life social stressor for female F1 pups that induces inefficient lactation associated with central changes in oxytocin (OXT), prolactin (PRL), and arginine vasopressin (AVP) gene expression in adult F1 females. The mothers of the rats in the current study were either allowed to raise their pups without exposure to a social stressor (control), or presented with a novel male intruder for 1h each day on lactation days 2-16 (chronic social stress). The effects of this early life chronic social stress (CSS) exposure on subsequent peripheral endocrinology, maternal behavior, and physiology were assessed. Exposure of female pups to early life CSS resulted in persistent alterations in maternal endocrinology at the end of lactation (attenuated prolactin and elevated corticosterone), depressed maternal care and aggression, increased restlessness and anxiety-related behavior, impaired lactation, and decreased saccharin preference. The endocrine and behavioral data indicate that early life CSS has long-term effects which are similar to changes seen in clinical populations of depressed mothers and provide support for the use of the chronic social stress paradigm as an ethologically relevant rodent model for maternal disorders such as postpartum depression and anxiety.
早期生活压力暴露是心理健康障碍的预测因素，两种常见的早期生活压力形式是社会冲突和母婴照顾受损，这是产后情绪障碍的主要特征。哺乳期雌性大鼠暴露于新雄性入侵者会导致强烈的社会冲突，并导致对 F1 后代的母婴照顾不足。这种暴露是雌性 F1 幼鼠的早期社会应激源，会导致泌乳效率低下，与成年 F1 雌性中的催产素 (OXT)、催乳素 (PRL) 和精氨酸加压素 (AVP) 基因表达的中枢变化有关。本研究中的母鼠要么允许其在没有暴露于社会应激源的情况下抚养幼鼠（对照），要么在哺乳期第 2-16 天每天与新雄性入侵者接触 1 小时（慢性社会应激）。评估了这种早期慢性社会应激（CSS）暴露对随后的外周内分泌、母婴行为和生理学的影响。幼鼠早期接触 CSS 会导致哺乳期结束时母体内分泌的持续改变（催乳素减弱和皮质酮升高）、母婴照顾和攻击性降低、不安和焦虑相关行为增加、泌乳能力下降以及蔗糖偏好减少。内分泌和行为数据表明，早期 CSS 具有长期影响，与临床抑郁母亲人群中观察到的变化相似，并支持将慢性社会应激范式用作产后抑郁和焦虑等母婴障碍的相关啮齿动物模型。
