Feng Sally, McGhee Katie E, Bell Alison M
School of Integrative Biology, University of Illinois, Urbana, IL, U.S.A.
Department of Zoology, University of Cambridge, Cambridge, U.K.
Anim Behav. 2015 Sep;107:61-69. doi: 10.1016/j.anbehav.2015.05.024. Epub 2015 Jul 8.
Maternal stress can have long-term negative consequences for offspring learning performance. However, it is unknown whether these maternal effects extend to the ability of offspring to apply previously learned information to new situations. In this study, we first demonstrate that juvenile threespine sticklebacks, , are indeed capable of generalizing an association between a colour and a food reward learned in one foraging context to a new foraging context (i.e. they can apply previously learned knowledge to a new situation). Next, we examined whether this ability to generalize was affected by maternal predator stress. We manipulated whether mothers were repeatedly chased by a model predator while yolking eggs (i.e. before spawning) and then assessed the learning performance of their juvenile offspring in groups and pairs using a colour discrimination task that associated a colour with a food reward. We found that maternal predator exposure affected the tendency of offspring to use social cues: offspring of predator-exposed mothers were faster at copying a leader's behaviour towards the rewarded colour than offspring of unexposed mothers. However, once the colour-reward association had been learned, offspring of predator-exposed and unexposed mothers were equally able to generalize their learned association to a new foraging task. These results suggest that offspring of predator-exposed mothers might be able to overcome learning deficits caused by maternal stress by relying more on social cues.
母体应激会对后代的学习表现产生长期负面影响。然而,这些母体效应是否会延伸至后代将先前所学信息应用于新情境的能力,目前尚不清楚。在本研究中,我们首先证明,幼年三刺鱼确实能够将在一种觅食情境中习得的颜色与食物奖励之间的关联推广到新的觅食情境中(即它们能够将先前所学知识应用于新情境)。接下来,我们研究了这种推广能力是否受到母体捕食者应激的影响。我们操纵了在母亲产卵前(即产卵前)给卵子授精时,母亲是否被模型捕食者反复追逐,然后使用将颜色与食物奖励相关联的颜色辨别任务,评估其幼年后代在群体和成对情况下的学习表现。我们发现,母体暴露于捕食者会影响后代使用社会线索的倾向:暴露于捕食者的母亲的后代比未暴露母亲的后代更快地模仿领导者对奖励颜色的行为。然而,一旦学会了颜色 - 奖励关联,暴露于捕食者和未暴露母亲的后代同样能够将所学关联推广到新的觅食任务中。这些结果表明,暴露于捕食者的母亲的后代可能能够通过更多地依赖社会线索来克服由母体应激导致的学习缺陷。