The effect of prenatal environment on brain mitochondrial function and prey detection in a lizard

Abstract

Abstract The ability to detect prey is crucial for survival in many animals. However, prey detection is a cognitive process that can be influenced by early life conditions such as prenatal stress or temperature. Mitochondrial function is likely to underlie these effects because cognitive abilities are energetically demanding (i.e. dependent on efficient metabolic function) and because metabolic‐derived oxidative stress and oxidative damage can impair cognitive function. Yet, whether prenatal stress and thermal environments affect prey detection, and whether mitochondrial function mediates such effects, remains poorly understood. Here, we investigated the links between prenatal environments, mitochondrial function and prey detection in the delicate skink ( Lampropholis delicata ). We manipulated egg corticosterone (CORT) levels—a key stress hormone in reptiles—and incubation temperature and assessed the ability of lizards to detect chemical and visual prey stimuli. Then, using flow cytometry, we measured metabolic function, oxidative stress and oxidative damage in the olfactory bulbs and optic tecta, two brain regions involved in sensory processing. While metabolic function and oxidative stress remained robust to early life conditions, CORT and temperature interacted to influence oxidative damage. Particularly, CORT decreased DNA damage in the olfactory bulbs of cold‐incubated lizards but had no effect on hot‐incubated lizards. In both brain regions, lipid peroxidation was lower in CORT‐treated lizards incubated at high temperatures compared to CORT‐treated cold‐incubated lizards, but no other between‐treatment differences were detected. Additionally, CORT‐treated lizards responded faster when presented with chemical cues but not visual stimuli. We did not find any relationship between mitochondrial function and prey detection. Our findings suggest that prenatal conditions have lasting effects on DNA damage and prey detection, but prey detection appears decoupled from mitochondrial function in L. delicata . Read the free Plain Language Summary for this article on the Journal blog.