Prenatal maternal stress impairs the development of cognitive abilities in Japanese quail (Coturnix c. japonica)
Résumé
It is well established that the prenatal environment can have profound and long-term influences on individual behavioural development. The exposure of a gestating or laying female to stressful events, affects their offspring’s emotional reactivity and social behaviour through hormonal modulations of fetal environment or yolk contents. In mammals, this prenatal maternal stress can also impact offspring’s cognitive abilities but in birds such effects have rarely been explored. This study aimed to evaluate the effect of prenatal maternal stress on Japanese quail’s learning capacities. For 24 days, laying quails were either submitted daily to unpredictable and repeated aversive stimuli (physical restraint, unexpected sounds, overcrowding, air or water spurt, etc.) or left undisturbed. Then, the emotional reactivity and learning abilities of females’ offspring were analyzed. Our results confirm that prenatal maternal stress affects emotional reactivity as stressed females’ offspring were more emotive in emergence and novel object tests than those of controls. But, we show also that prenatal maternal stress impairs offspring’s learning abilities. Firstly, stressed females’ chicks were less efficient during the probe test of a spatial learning task. Secondly, they failed in a conditioned place preference test as contrary to the control birds, they were not able to learn the rewarded place. Here we evidence that prenatal maternal stress impacts offspring’s behavioural development and cognitive abilities that may impair individual’s capacity to adapt to their environment.