Saiz Nuria, Herrera-Castillo Lisbeth, de Pedro Nuria, Delgado María Jesús, Arvidsson Sven David, Marugal-López Miguel Ángel, Isorna Esther
Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid, 28040 Madrid, Spain.
Animals (Basel). 2023 Aug 1;13(15):2481. doi: 10.3390/ani13152481.
Chronodisruption caused by factors such as light at night and mistimed meals has been linked to numerous physiological alterations in vertebrates and may be an anxiogenic factor affecting welfare. This study aims to investigate whether chronodisruption causes measurable changes in the anxiety responses of goldfish under two conditions: randomly scheduled feeding (RF) and continuous light (LL). Anxiety-like behavior was assessed in the open field with object approach and black/white preference tests, which had been validated using diazepam. An increased thigmotaxis response and decreased object exploration under both chronodisruption protocols indicated anxiety states. Furthermore, locomotor activity was increased in LL fish. The black/white preference test discriminated anxiolysis induced by diazepam but was unable to detect anxiety caused by chronodisruption. Plasma cortisol increased in both RF and LL fish throughout the experiment, confirming that both conditions caused stress. The LL fish also showed an apparently desensitized hypothalamus-pituitary-interrenal HPI axis, with a decrease in and expression. Individual analysis found no correlation between anxiety-like behavior and stress axis activation nor between scototaxis and thigmotaxis responses. However, individual differences in sensitivity to each test were detected. Altogether, these results highlight circadian disruption as a stressor for fish and endorse a multiple variable approach for reliably assessing animal discomfort.
由夜间光照和进餐时间不规律等因素导致的昼夜节律紊乱与脊椎动物的多种生理变化有关，可能是影响动物福利的一个致焦虑因素。本研究旨在探讨在随机定时投喂（RF）和持续光照（LL）两种条件下，昼夜节律紊乱是否会导致金鱼焦虑反应出现可测量的变化。通过物体接近和黑白偏好测试在旷场中评估类似焦虑的行为，这两种测试已使用地西泮进行了验证。在两种昼夜节律紊乱方案下，趋触性反应增加和物体探索减少表明处于焦虑状态。此外，LL组金鱼的运动活动增加。黑白偏好测试能够区分地西泮诱导的抗焦虑作用，但无法检测到昼夜节律紊乱引起的焦虑。在整个实验过程中，RF组和LL组金鱼的血浆皮质醇均升高，证实两种条件都引起了应激。LL组金鱼还表现出下丘脑-垂体-肾间组织（HPI）轴明显脱敏， 和 的表达减少。个体分析发现，类似焦虑的行为与应激轴激活之间、避光性和趋触性反应之间均无相关性。然而，检测到了个体对每项测试敏感性的差异。总之，这些结果突出了昼夜节律紊乱是鱼类的一个应激源，并支持采用多变量方法来可靠地评估动物的不适。
