Hughes Robert N, Hancock Nicola J
Department of Psychology, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
Department of Psychology, University of Canterbury, Private Bag 4800, Christchurch 8140, New Zealand.
Pharmacol Biochem Behav. 2016 Jan;140:51-61. doi: 10.1016/j.pbb.2015.11.005. Epub 2015 Nov 11.
To assess the possibility that acute caffeine's behavioral action might depend on rats' strain, effects of 50mg/kg of the drug were observed on activity, anxiety-related behavior and habituation learning in male and female rats from three different strains, namely PVG/c, Long-Evans and Wistar. All subjects were tested in an open field, an elevated plus maze and a light-dark box. For the three strains combined, increased occupancy of the center of the open field and entries of the open plus-maze arms with caffeine suggested caffeine-induced anxiolysis, whereas increased grooming in the open field, decreased rearing in the plus maze and increased risk assessment in the light-dark box were consistent with anxiogenesis. Caffeine also reduced open-field rearing only for PVG/c rats, and entries into and occupation of the light side of the light-dark box only for Long-Evans rats, and increased total defecation in the three types of apparatus for all three strains combined. Overall, caffeine appeared to be mainly anxiogenic. The drug also increased open-field ambulation for PVG/c rats and walking for all rats, but decreased open-field ambulation and entries into the plus maze closed arms for Wistar rats alone. In general, Wistar rats appeared to be the least and Long-Evans the most anxious of the three strains investigated. Caffeine also decreased within-session habituation of open-field ambulation for PVG/c rats alone, thereby suggesting strain-dependent interference with non-associative learning and short-term memory. Several overall sex differences were also observed that supported female rats being more active and less anxious than males.
为了评估急性咖啡因的行为作用可能取决于大鼠品系的可能性，观察了50mg/kg该药物对来自三种不同品系（即PVG/c、Long-Evans和Wistar）的雄性和雌性大鼠的活动、焦虑相关行为及习惯化学习的影响。所有实验对象均在旷场、高架十字迷宫和明暗箱中进行测试。对于这三个品系的大鼠而言，咖啡因使旷场中央的停留时间增加以及高架十字迷宫开放臂的进入次数增加，这表明咖啡因诱导了抗焦虑作用，而在旷场中理毛行为增加、在十字迷宫中直立行为减少以及在明暗箱中风险评估行为增加则与焦虑产生一致。咖啡因还仅使PVG/c大鼠的旷场直立行为减少，仅使Long-Evans大鼠进入和停留在明暗箱亮侧的次数减少，并且使所有三个品系的大鼠在这三种实验装置中的总排便量增加。总体而言，咖啡因似乎主要产生致焦虑作用。该药物还使PVG/c大鼠的旷场行走以及所有大鼠的步行增加，但仅使Wistar大鼠的旷场行走和进入十字迷宫封闭臂的次数减少。一般来说，在被研究的这三个品系中，Wistar大鼠似乎最不焦虑，而Long-Evans大鼠最焦虑。咖啡因还仅使PVG/c大鼠在旷场行走的实验过程中的习惯化减少，从而表明对非联想学习和短期记忆存在品系依赖性干扰。还观察到了一些总体上的性别差异，这些差异表明雌性大鼠比雄性大鼠更活跃且焦虑程度更低。
