Programa de pós Graduação em Farmacologia, Universidade Federal de Santa Maria, RS, Brazil.
Stress. 2013 May;16(3):321-30. doi: 10.3109/10253890.2012.723075. Epub 2012 Oct 8.
This study investigated the influence of neonatal handling on behavioral and biochemical consequences of chronic mild stress (CMS) in adulthood. Male rat pups were submitted to daily tactile stimulation (TS) or maternal separation (MS), from postnatal day 1 (PND1) to postnatal day 21 (PND21), for 10 min/day. In adulthood, half the number of animals were exposed to CMS for 3 weeks and submitted to behavioral testing, including sucrose preference (SP), elevated plus maze (EPM), and defensive burying tasks (DBTs), followed by biochemical assessments. CMS reduced SP, increased anxiety in EPM and DBT, and increased adrenal weight. In addition, CMS decreased plasma vitamin C (VIT C) levels and increased protein carbonyl (PC) levels, catalase (CAT) activity in hippocampus and cortex, and superoxide dismutase (SOD) levels in cortex. In contrast, both forms of neonatal handling were able to prevent reduction in SP, anxiety behavior in DBT, and CMS-induced adrenal weight increase. Furthermore, they were also able to prevent plasma VIT C reduction, hippocampal PC levels increase, CAT activity increase in hippocampus and cortex, and SOD levels increase in cortex following CMS. Only TS was able to prevent CMS-induced anxiety symptoms in EPM and PC levels in cortex. Taken together, these findings show the protective role of neonatal handling, especially TS, which may enhance ability to cope with stressful situations in adulthood.
本研究探讨了新生期处理对成年期慢性轻度应激(CMS)的行为和生化后果的影响。雄性幼鼠从出生后第 1 天(PND1)到第 21 天(PND21)每天接受 10 分钟的触觉刺激(TS)或母婴分离(MS)。成年后,一半数量的动物接受 CMS 处理 3 周,并进行行为测试,包括蔗糖偏好(SP)、高架十字迷宫(EPM)和防御性掩埋任务(DBTs),然后进行生化评估。CMS 降低了 SP,增加了 EPM 和 DBT 的焦虑,增加了肾上腺重量。此外,CMS 降低了血浆维生素 C(VIT C)水平,增加了海马体和皮质中的蛋白质羰基(PC)水平、CAT 活性,以及皮质中的超氧化物歧化酶(SOD)水平。相比之下,两种形式的新生期处理都能够防止 SP 降低、DBT 中的焦虑行为和 CMS 引起的肾上腺重量增加。此外,它们还能够防止 CMS 引起的血浆 VIT C 降低、海马体 PC 水平升高、海马体和皮质中的 CAT 活性升高以及皮质中的 SOD 水平升高。只有 TS 能够预防 CMS 引起的 EPM 焦虑症状和皮质中的 PC 水平升高。总之,这些发现表明新生期处理,特别是 TS,具有保护作用,可能增强成年期应对应激情况的能力。