Predation risk can program offspring behavior, physiology, and fitness through maternal effect, but most studies have mainly focused on this effect during pregnancy; little is known about the effect of postpartum predation risk on offspring’s phenotype. Here, we compared the antipredator behaviors of adult offspring (approximately 90 days old) produced by female Brandt’s voles (Lasiopodomys brandtii) exposed to one of three treatments: cat odor (CO), rabbit odor (RO), and distilled water (DW) for 60 min daily from postpartum day 1–18. Basal levels of plasma adrenocorticotropic hormone (ACTH) and corticosterone (CORT), hypothalamic corticotrophin releasing hormone (CRH), as well as spleen immunoglobulins (IgA, IgM, and IgG) were also measured. Our data showed that the offspring of CO-exposed mothers displayed less head-out behavior to acute 15-min CO exposure, and female offspring showed more freezing behavior. CO offspring showed significantly lower basal ACTH and CORT levels than the RO and DW offspring. Additionally, female but not male CO offspring had higher hypothalamic CRH expression and spleen IgG levels than controls, showing a sex-specific effect. These findings demonstrate that postpartum maternal predator risk exposure promotes a passive-avoidant response to these cues in adult offspring, showing a cross-generational maternal effect of postpartum predation risk. Further, these changes may be associated with alterations in the hypothalamic-pituitary-adrenal axis and immune function.

捕食风险可以通过母体效应来规划后代的行为、生理和健康，但大多数研究主要集中在怀孕期间的这种效应上；关于产后捕食风险对后代表型的影响知之甚少。在这里，我们比较了雌性勃兰特田鼠 ( Lasiopodomys brandtii )产生的成年后代（大约 90 天大）的抗捕食行为，它们暴露于以下三种处理之一：猫气味 (CO)、兔子气味 (RO) 和蒸馏水 (DW)从产后第 1-18 天开始，每天 60 分钟。血浆促肾上腺皮质激素(ACTH) 和皮质酮(CORT)、下丘脑促肾上腺皮质激素释放激素 (CRH) 以及脾脏的基础水平还测量了免疫球蛋白（IgA、IgM 和 IgG）。我们的数据显示，暴露于 CO2 的母亲的后代在急性 15 分钟 CO2 暴露时表现出较少的头部外露行为，而雌性后代表现出更多的冷漠行为。CO 后代的基础 ACTH 和 CORT 水平显着低于 RO 和 DW 后代。此外，雌性而非雄性 CO 后代的下丘脑 CRH 表达和脾脏 IgG 水平高于对照组，显示出性别特异性效应。这些发现表明，产后母体捕食者风险暴露促进了成年后代对这些线索的被动回避反应，显示出产后捕食风险的跨代母体效应。此外，这些变化可能与下丘脑-垂体-肾上腺轴和免疫功能的改变有关。