Effect of maternal predator exposure on the ability of stickleback offspring to generalize a learned colour–reward association

Abstract

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, Gasterosteus aculeatus, 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.

Transgenerational transmission of a stress-coping phenotype programmed by early-life stress in the Japanese quail

“…This is in agreement with previous studies in the Japanese quail and others species showing that the pre-natal period is a sensitive period to stress that could result in long-term impacts on the phenotype (human and rodents27845, guinea pig46, birds47, chicken4849, Japanese quail6142450, threespine stickleback1051, guppies52). However, in some other species post-natal experience does have a strong effect on individual phenotype (rat9155354, zebra finch445556575859).…”

Secondhand horror: effects of direct and indirect predator cues on behavior and reproduction of the bank vole

“…However, the mechanisms and adaptive value of delayed or suppressed breeding under risk are not clear and continue to be debated Lima 1997, Kokko andRuxton 2000). Several publications have already explored the effects of increased risk of predation in parents' environment on offspring behavior and fitness, finding altered learning behavior in three-spine sticklebacks (Gasterosteus aculeatus; Roche et al 2012, Feng et al 2015, altered stress reaction in C57BL/6 mice and Long Evans rats McGowan 2015, St-Cyr et al 2017), or changed foraging strategies in Sprague Dawley rats (Chaby et al 2015). …”

Intraspecific variation in cue-specific learning in sticklebacks

“…In this version of the discrimination task, sticklebacks were presented with a yellow and blue cup and were trained to associate the blue cup with a food reward. Sticklebacks are known to discriminate between these two colours (Bensky, Paitz, Pereira, & Bell, 2017; Feng, McGhee, & Bell, 2015; Roche, McGhee, & Bell, 2012), and pilot experiments found no evidence of a colour bias in either of the two populations (mean ± SD proportion of preference trials in which sticklebacks chose blue: Navarro: 0.39 ± 0.303, t 9 = 1.1595, P = 0.2761; Putah: 0.44 ± 0.227, t 9 = 0.8358, P = 0.4249). The stickleback was placed in the shelter at the back of the tank.…”