Merrill Loren, Grindstaff Jennifer L
Oklahoma State University, Department of Integrative Biology, Stillwater, OK 74078, USA; Illinois Natural History Survey, University of Illinois, Champaign, IL 61820, USA.
Oklahoma State University, Department of Integrative Biology, Stillwater, OK 74078, USA.
Brain Behav Immun. 2015 Mar;45:71-9. doi: 10.1016/j.bbi.2014.12.013. Epub 2014 Dec 20.
Both maternal exposure to stressors and exposure of offspring to stressors during early life can have lifelong effects on the physiology and behavior of offspring. Stress exposure can permanently shape an individual's phenotype by influencing the development of the hypothalamic-pituitary-adrenal (HPA) axis, which is responsible for the production and regulation of glucocorticoids such as corticosterone (CORT). In this study we used captive zebra finches (Taeniopygia guttata) to examine the effects of matching and mismatching maternal and early post-natal exposure to one of two types of antigens or a control on HPA axis reactivity in adult offspring. Prior to breeding, adult females were injected with lipopolysaccharide (LPS), keyhole limpet hemocyanin (KLH) or a control. Offspring of females in each of the three treatments were themselves exposed to LPS, KLH or a control injection at 5 and 28days post-hatch. When offspring were at least 18months of age, standardized capture and restraint stress tests were conducted to determine the impact of the treatments on adult stress responsiveness. We found significant interaction effects between maternal and offspring treatments on stress-induced CORT levels, and evidence in support of the environment matching hypothesis for KLH-treated birds, not LPS-treated birds. KLH-treated offspring of KLH-treated mothers exhibited reduced stress-induced CORT levels, whereas LPS-treated or control offspring of KLH-treated mothers exhibited elevated stress-induced CORT levels. Although the treatment effects on baseline CORT were non-significant, the overall pattern was similar to the effects observed on stress-induced CORT levels. Our results highlight the complex nature of HPA axis programming, and to our knowledge, provide the first evidence that a match or mismatch between pre and post-natal antigen exposure can have life-long consequences for HPA axis function.
母体在孕期暴露于应激源以及子代在生命早期暴露于应激源，均可对后代的生理和行为产生终身影响。应激暴露可通过影响下丘脑 - 垂体 - 肾上腺（HPA）轴的发育，永久性地塑造个体的表型，该轴负责皮质酮（CORT）等糖皮质激素的产生和调节。在本研究中，我们使用圈养的斑胸草雀（Taeniopygia guttata）来研究母体和产后早期暴露于两种抗原之一或对照物的匹配与不匹配情况，对成年后代HPA轴反应性的影响。在繁殖前，成年雌性被注射脂多糖（LPS）、钥孔戚血蓝蛋白（KLH）或对照物。三种处理中每种处理的雌性后代在孵化后5天和28天自身接受LPS、KLH或对照注射。当后代至少18个月大时，进行标准化的捕捉和束缚应激试验，以确定这些处理对成年应激反应性的影响。我们发现母体和后代处理之间对应激诱导的CORT水平存在显著的交互作用，并且有证据支持经KLH处理的鸟类（而非经LPS处理的鸟类）的环境匹配假说。经KLH处理的母亲所生的经KLH处理的后代，应激诱导的CORT水平降低，而经KLH处理的母亲所生的经LPS处理或对照的后代，应激诱导的CORT水平升高。尽管处理对基线CORT的影响不显著，但总体模式与对应激诱导的CORT水平观察到的影响相似。我们的结果突出了HPA轴编程的复杂性，据我们所知，首次提供了证据表明产前和产后抗原暴露之间的匹配或不匹配可对HPA轴功能产生终身影响。
