Kroll Tina, Kornadt-Beck Nikola, Oskamp Angela, Elmenhorst David, Touma Chadi, Palme Rupert, Bauer Andreas
Institute of Neuroscience and Medicine (INM-2), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Central Animal Facility (ZT), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
Animals (Basel). 2021 Mar 5;11(3):710. doi: 10.3390/ani11030710.
Since animal experiments cannot be completely avoided, the pain, suffering, and distress of laboratory animals must be minimized. To this end, a major prerequisite is reliable assessment of pain and distress. Usually, evaluation of animal welfare is done by visual inspection and score sheets. However, relatively little is known about whether standardized, but subjective, score sheets are able to reliably reflect the status of the animals. The current study aimed to compare visual assessment scores and changes in body weight with concentrations of fecal corticosterone metabolites (FCMs) in a neuroscientific experimental setup. Additionally, effects of refinement procedures were investigated. Eight male adult Sprague-Dawley rats underwent several experimental interventions, including electroencephalograph electrode implantation and subsequent recording, positron emission tomography (PET), and sleep deprivation (SD) by motorized activity wheels. Additional 16 rats were either used as controls without any treatment or to evaluate refinement strategies. Stress responses were determined on a daily basis by means of measuring FCMs, body weight, and evaluation of the animals' welfare by standardized score sheets. Surgery provoked a significant elevation of FCM levels for up to five days. Increases in FCMs due to PET procedures or SD in activity wheels were also highly significant, while visual assessment scores did not indicate elevated stress levels and body weights remained constant. Visual assessment scores correlate with neither changes in body weight nor increases in FCM levels. Habituation procedures to activity wheels used for SD had no impact on corticosterone release. Our results revealed that actual score sheets for visual assessment of animal welfare did not mirror physiological stress responses assessed by FCM measurements. Moreover, small changes in body weight did not correlate with FCM concentration either. In conclusion, as visual assessment is a method allowing immediate interventions on suffering animals to alleviate burden, timely stress assessment in experimental rodents via score sheets should be ideally complemented by validated objective measures (e.g., fecal FCM measured by well-established assays for reliable detection of FCMs). This will complete a comprehensive appraisal of the animals' welfare status in a retrospective manner and refine stressor procedures in the long run.
由于动物实验无法完全避免，因此必须将实验动物的疼痛、痛苦和苦恼降至最低。为此，一个主要前提是对疼痛和苦恼进行可靠评估。通常，通过目视检查和评分表来评估动物福利。然而，对于标准化但主观的评分表是否能够可靠地反映动物的状态，人们了解得相对较少。当前的研究旨在比较在神经科学实验设置中，视觉评估分数和体重变化与粪便皮质酮代谢物（FCM）浓度之间的关系。此外，还研究了优化程序的效果。八只成年雄性Sprague-Dawley大鼠接受了多种实验干预，包括脑电图电极植入及后续记录、正电子发射断层扫描（PET）以及通过电动活动轮进行睡眠剥夺（SD）。另外16只大鼠要么用作未接受任何处理的对照，要么用于评估优化策略。每天通过测量FCM、体重以及使用标准化评分表评估动物福利来确定应激反应。手术导致FCM水平显著升高，持续长达五天。PET程序或活动轮中的SD导致的FCM增加也非常显著，而视觉评估分数并未表明应激水平升高，体重保持不变。视觉评估分数与体重变化和FCM水平升高均无关联。用于SD的活动轮的习惯化程序对皮质酮释放没有影响。我们的结果表明，用于动物福利视觉评估的实际评分表并未反映通过FCM测量评估的生理应激反应。此外，体重的微小变化也与FCM浓度无关。总之，由于视觉评估是一种允许对痛苦动物立即进行干预以减轻负担的方法，因此通过评分表对实验啮齿动物进行及时的应激评估，理想情况下应以经过验证的客观测量方法（例如，通过成熟的检测方法可靠检测FCM的粪便FCM测量）作为补充。这将以回顾性方式完成对动物福利状况的全面评估，并从长远角度优化应激源程序。
