Recio Pablo, Leibold Dalton C, Crino Ondi L, Friesen Christopher R, Noble Daniel W A
Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia.
Flinders University, College of Science and Engineering, Bedford Park, SA 5042, Australia.
J Exp Biol. 2025 Aug 1;228(15). doi: 10.1242/jeb.250716. Epub 2025 Aug 12.
Early environmental factors such as heat or stress hormones can impair learning through brain metabolic function, which is crucial for neural development and synaptic plasticity. However, whether early environments always result in cognitive impairment through changes in neural physiology is not well established outside of a few model systems. Here, we investigated the effects of prenatal temperature and corticosterone (CORT) on brain mitochondrial activity and spatial learning in the delicate skink (Lampropholis delicata). We treated eggs with either CORT or a control vehicle and incubated at cold (23±3°C) or hot (28±3°C) temperatures. Juveniles were tested in a spatial learning task over 40 days after which mitochondrial function in the medial cortex was assessed. Despite among-individual variation in learning ability, mitochondrial physiology and spatial learning in L. delicata remained robust to prenatal temperature and CORT exposure. No significant relationship was found between mitochondrial function and cognitive performance, contrary to predictions. Increased metabolic capacity correlated with higher production of reactive oxygen species but did not affect oxidative damage, possibly as a result of protective mechanisms. These findings highlight the physiological and cognitive resilience of L. delicata to early-life challenges. Future research should explore whether this robustness extends to other brain regions, cognitive domains and life stages.
早期环境因素，如高温或应激激素，可通过影响大脑代谢功能来损害学习能力，而大脑代谢功能对神经发育和突触可塑性至关重要。然而，除了少数模型系统外，早期环境是否总是通过神经生理学变化导致认知障碍，目前还不太明确。在这里，我们研究了产前温度和皮质酮（CORT）对细脆蛇蜥（Lampropholis delicata）大脑线粒体活性和空间学习的影响。我们用CORT或对照载体处理蛇蜥卵，并在低温（23±3°C）或高温（28±3°C）下孵化。幼体在40天内接受空间学习任务测试，之后评估内侧皮质的线粒体功能。尽管个体间学习能力存在差异，但细脆蛇蜥的线粒体生理学和空间学习能力对产前温度和CORT暴露仍具有较强的耐受性。与预测相反，未发现线粒体功能与认知表现之间存在显著关系。代谢能力的提高与活性氧的产生增加相关，但并未影响氧化损伤，这可能是由于保护机制所致。这些发现突出了细脆蛇蜥对早期生活挑战的生理和认知恢复能力。未来的研究应探索这种耐受性是否扩展到其他脑区、认知领域和生命阶段。
