While post-traumatic stress disorder (PTSD) can develop after exposure to severe traumatic events, data have shown that individuals with high sensation-seeking personality traits are less prone to developing PTSD. The current study used the rodent environmental enrichment preclinical model of sensation-seeking to determine if similar sensation seeking effects in animal models of PTSD-like behaviors were found. The study also attempted to determine whether environmental enrichment altered the effects of midazolam on these PTSD-like behaviors. Male Sprague-Dawley rats were received at postnatal day (PND) 21 and placed into either an enriched (EC), isolated (IC), or social (SC) condition. Beginning on PND 51, the animals underwent 3 fear conditioning trials where a tone was paired with a 2 s 0.7 mA footshock. Twenty-four hours later, rats were given 15-min i.p. pretreatments of 0, 0.5, or 1.5 mg/kg midazolam, before being placed into fear conditioning chambers for a test of expression of conditioned fear response in a novel context. Following fear conditioning, rodents were also tested in the elevated plus maze (EPM) and the forced swim task (FST) following pretreatments of midazolam. Results from fear conditioning indicated IC rats showed a significant decrease in freezing during acquisition compared to EC and SC rats. Also, during expression, IC rats had lower freezing following saline injections and 0.5 mg/kg midazolam but were equal in time freezing to EC and SC rats following 1.5 mg/kg midazolam. In the EPM there were no effects of midazolam and IC rats showed decreased time spent in the open arms compared to EC and SC rats. In FST, IC rats spent less time immobile and more time swimming compared to EC and SC rats. Overall, results suggest that the rodent environmental enrichment model of sensation-seeking seems to parallel the effects of sensation-seeking on likelihood of PTSD symptoms seen in humans.

虽然创伤后应激障碍（PTSD）在暴露于严重的创伤事件后会发展，但数据显示，具有高感觉寻求性格特征的人不太容易发展为PTSD。当前的研究使用了啮齿动物寻求感觉的环境丰富的临床前模型，以确定在类似PTSD行为的动物模型中是否发现了类似的感觉寻求作用。该研究还试图确定环境的富集是否改变了咪达唑仑对这些PTSD样行为的影响。在出生后第21天（PND）接受雄性Sprague-Dawley大鼠，并将其置于充实（EC），孤立（IC）或社交（SC）状态。从PND 51开始，对这些动物进行了3次恐惧适应试验，其中音调与2 s 0.7 mA的电击配对。二十四小时后 在将大鼠置于恐惧调节室内进行新条件下的条件恐惧反应表达测试之前，对它们进行了0、0.5或1.5 mg / kg咪达唑仑的15分钟ip预处理。经过恐惧调节后，在咪达唑仑预处理后的高空迷宫（EPM）和强制游泳任务（FST）中也测试了啮齿动物。恐惧调节的结果表明，与EC和SC大鼠相比，IC大鼠在采集过程中的冰点明显降低。同样，在表达过程中，IC大鼠在注射盐水和0.5 mg / kg咪达唑仑后的冻结率较低，但在冷冻时间上与1.5 mg / kg咪达唑仑后的EC和SC大鼠的冻结时间相等。在EPM中，没有咪达唑仑的作用，与EC和SC大鼠相比，IC大鼠的张开双臂的时间减少了。在FST中，与EC和SC大鼠相比，IC大鼠的固定时间更少，游泳时间更长。总体而言，结果表明，寻求知觉的啮齿动物环境富集模型似乎与寻求知觉对人类所见PTSD症状的可能性的影响相似。