Šikić Dunja, Turković Lu, Malev Olga, Gojak Tomislav, Lisičić Duje, Sertić Miranda, Blažević Sofia Ana
Faculty of Science, Division of Biology, Department of Animal Physiology, University of Zagreb, Horvatovac 102a, Zagreb, 10000, Croatia.
Faculty of Pharmacy and Biochemistry, Department of Pharmaceutical Analysis, University of Zagreb, Ante Kovačića 1, Zagreb, 10000, Croatia.
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2025 Jul 24. doi: 10.1007/s00359-025-01753-6.
Monoamines play essential roles in regulating brain functions, influencing behaviours and physiological processes. Despite significant advances in mammalian models, studies on reptiles are limited, restricting our understanding of their neurochemical and behavioural interactions. This study aimed to develop and validate a selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous quantification of 11 monoamines and their metabolites (adrenaline, dopamine, levodopa, homovanillic acid, 5-hydroxyindoleacetic acid, 5-hydroxytryptophan, serotonin, norepinephrine, tryptophan, tyrosine, vanillylmandelic acid) in lizard brains, examining interspecies and sex-specific variations and their potential link to behavioural differences between Podarcis siculus and Podarcis melisellensis. Brain samples from 132 lizards were analysed using the optimized LC-MS/MS method, which included rigorous pre-analytical preparation to ensure analyte stability. The method demonstrated high sensitivity and specificity for monoamines, with the limit of quantitation lower than 5 ng mL. Statistical analyses were performed to assess species, sex, and interaction effects. Significant species differences were observed in tryptophan, 5-hydroxytryptophan and 5-hydroxyindoleacetic acid, with P. siculus males exhibiting the highest levels. No differences were found in the dopamine, noradrenaline or adrenaline pathways. Serotonergic differences align with previously recorded behavioural differences between these two species. This is the first comprehensive study profiling monoamines in lizard brains using LC-MS/MS, providing insights into species-specific neurochemical patterns. The findings underscore the utility of lizards as comparative models in neuroscience and highlight the need for further research into the interplay between neurochemistry and behaviour.
单胺类物质在调节大脑功能、影响行为和生理过程中发挥着重要作用。尽管在哺乳动物模型方面取得了重大进展，但对爬行动物的研究仍然有限，这限制了我们对它们神经化学和行为相互作用的理解。本研究旨在开发并验证一种选择性液相色谱 - 串联质谱（LC-MS/MS）方法，用于同时定量蜥蜴大脑中的11种单胺类物质及其代谢产物（肾上腺素、多巴胺、左旋多巴、高香草酸、5-羟吲哚乙酸、5-羟色氨酸、血清素、去甲肾上腺素、色氨酸、酪氨酸、香草扁桃酸），研究种间和性别特异性差异及其与意大利壁蜥（Podarcis siculus）和梅氏壁蜥（Podarcis melisellensis）行为差异的潜在联系。使用优化后的LC-MS/MS方法分析了132只蜥蜴的脑样本，该方法包括严格的分析前准备以确保分析物的稳定性。该方法对单胺类物质具有高灵敏度和特异性，定量限低于5 ng/mL。进行了统计分析以评估物种、性别和相互作用的影响。在色氨酸、5-羟色氨酸和5-羟吲哚乙酸中观察到显著的物种差异，意大利壁蜥雄性的含量最高。在多巴胺、去甲肾上腺素或肾上腺素途径中未发现差异。血清素能差异与这两个物种先前记录的行为差异一致。这是首次使用LC-MS/MS对蜥蜴大脑中的单胺类物质进行全面分析的研究，为物种特异性神经化学模式提供了见解。研究结果强调了蜥蜴作为神经科学中比较模型的实用性，并突出了进一步研究神经化学与行为之间相互作用的必要性。
