Laboratório Especial de Dor e Sinalização, Instituto Butantan, São Paulo, SP, Brazil; Departamento de Farmacologia, Instituto de Ciências Biomédicas I, Universidade de São Paulo, SP, Brazil.
Biotério Central, Instituto Butantan, São Paulo, SP, Brazil.
Behav Brain Res. 2019 May 17;364:442-446. doi: 10.1016/j.bbr.2017.11.012. Epub 2017 Nov 11.
Environmental enrichment (EE) can alter anxiety as well as perception of nociceptive stimuli, suggesting a relationship between well-being and analgesia. Considering that, we aimed to evaluate the influence of different EE types on anxiety and peripheral pain sensitivity of male Wistar rats. Animals were submitted to two different types of EE: On the first one, animals were housed in standard size cages after weaning and received three different objects, one type per week, on a regular basis (simple EE - sEE). On the second one, animals were born in an already enriched environment and, after five weeks, were housed in larger cages and received five different objects, three of each type per week, on a regular basis (improved EE - iEE). Control group remained in standard cages and did not receive objects. Within 7 weeks of life, anxiety and thermal sensibility were evaluated using elevated plus maze and tail flick tests, respectively. Mechanical hyperalgesia was analyzed in the presence of acute and chronic noxious stimuli by paw pressure test. Both EE protocols tested were effective in diminish anxiety but they did not alter thermal sensibility. On the other hand, sEE protocol did not alter acute and chronic induced mechanical hypersensitivity, whereas iEE completely abolished such pain behavior, even without exercise wheel as part of the enrichment. Our results show that specific parameters (anxiety and pain sensitivity) can be differentially modulated depending on EE protocol used, making possible the implementation of welfare to experimental animals in pain research.
环境丰富（EE）可以改变焦虑以及对伤害性刺激的感知，这表明幸福感和镇痛之间存在关系。考虑到这一点，我们旨在评估不同 EE 类型对雄性 Wistar 大鼠焦虑和外周疼痛敏感性的影响。动物被分为两组进行 EE：第一组在断奶后被安置在标准大小的笼子中，并定期收到三种不同的物体，每周一种类型（简单 EE - sEE）。第二组在已经丰富的环境中出生，五周后被安置在更大的笼子中，并定期收到五种不同的物体，每种类型三种（改进 EE - iEE）。对照组仍留在标准笼子中，没有收到物体。在生命的 7 周内，使用高架十字迷宫和尾巴拍打测试分别评估焦虑和热敏感性。通过足底压力测试分析急性和慢性有害刺激下的机械性痛觉过敏。两种 EE 方案都有效减轻了焦虑，但并未改变热敏感性。另一方面，sEE 方案并未改变急性和慢性诱导的机械性敏感性增加，而 iEE 则完全消除了这种疼痛行为，即使没有作为丰富内容一部分的运动轮。我们的结果表明，特定参数（焦虑和疼痛敏感性）可以根据使用的 EE 方案进行差异调节，从而有可能在疼痛研究中为实验动物实施福利。
