Abstract: Protective effects of enriched environment exposure on brain damage caused by seizures in rats. Zhou Jianping*， Wang Fan,Yang Lin， et al. * Department of Pediatrics，the Second Hospital Attached to Medical College of Xi’an Jiaotong University，Xi’an 710004，China AbstractObjectiveTo explore the potentiality of the protection by enriched environment exposure to rats brain damaged by repeated seizures. MethodsThirty 21dayold male SpragueDawley (SD) rats after 10 seizures with hyperthermal bath were randomly divided into long term enriched environment exposure group(LG),short term enriched environment exposure group(SG) and control group(CG).Groups LG and SG accepted 10 and 5 days enriched environment exposure respectively.No intervention measurements were given to rats in CG group.The changes of emotion,behavior,learning and memory were observed with open field test (OFT),passive avoidance test (PAT) and Morris water maze (MWM) test in all of the three groups. ResultsData collected from this study indicated that enriched environment exposure to rats with repeated seizures could prolong memory latencies (the memory latencies respectively were 32342±9838s for LG,27652±9264s for SG and 19713±9511s for CG,P<001 ) and decrease the wrong reactions(the times of wrong reactions respectively were 175±101 for LG,214±113 for SG and 537±126 for CG,P<001) in PAT.In OFT,there were high nerve excitation(the scores respectively were 6235±781 for LG,5367±766 for SG and 4548±734 for CG,P<001),increased adaptability to unfamiliar environment(the times of standing up by hind legs respectively were 3337±474 for LG,2618±423 for SG and 1719±431 for CG,P<001) and notable relief of nervousness(the numbers of dung respectively were 385±201 for LG,614±198 for SG and 1162±212 for CG,P<001)under enriched environment exposure.Data from MWM revealed that rats’ escape latencies reduced and search strategies improved(the percentages of straight strategy respectively were 378% for LG, 336% for SG and 272% for CG,χ2=4102,P<0005) under enriched environment exposure.Analysis of variance and qtest and chisquare test on the data collected from the 3 groups above revealed that there were significant differences between LG and the other two groups. ConclusionThe present study suggests that enriched environment exposure can relieve the impairments of emotion,behavior,learning and memory and protect brain of rat from being damaged by repeated seizures.

Key words: Behavior, Morris water maze , Seizure, Learning and memory

摘要： 目的探讨丰富环境对大鼠惊厥性脑损伤是否具有保护作用。 方法200408西安交通大学医学院对30只21日龄雄性SD大鼠经水浴法诱导反复惊厥10次后随机均分为长程丰富环境暴露组(LG)、短程丰富环境暴露组(SG)和对照组(CG)。LG、SG组分别暴露于丰富环境中10d和5d，CG组不给予干预措施。观察各组大鼠在避暗试验(passive avoidance test,PAT)、Morris水迷宫(Morris water maze,MWM)及旷场试验(open field test,OFT)中学习记忆和情感行为的变化。 结果丰富环境暴露可使反复惊厥大鼠在PAT中的记忆潜伏期延长\[LG组为(32342±9838)s，SG组为(27652±9264)s，CG组为(19713±9511)s，P<001\]，错误反应次数减少(LG组为175±101，SG组为214±113，CG组为537±126，P<001)；在OFT中，丰富环境暴露可增强反复惊厥大鼠的兴奋性(LG组得分为6235±781，SG组为5367±766，CG组为4548±734，P<001)，提高大鼠对陌生环境的适应能力(LG组后肢性站立的次数为3337±474，SG组为2618±423，CG组为1719±431，P<001)，改善大鼠的紧张情绪(LG组粪便粒数为385±201，SG组为614±198，CG组为1162±212，P<001)；在MWM中，丰富环境暴露可使反复惊厥大鼠逃逸潜伏期缩短，搜寻策略改善(LG、SG及CG组直线式搜寻策略所占百分比依次为378%、336%及272%,χ2=4102,P<0005)。 结论丰富环境暴露可以改善反复惊厥大鼠的学习记忆和情感行为，对惊厥性脑功能损伤具有保护作用。

关键词: 丰富环境, 惊厥, 学习记忆, 行为, Morris水迷宫