【摘要】 目的了解不同放射剂量对大鼠学习记忆能力的影响及其关系。方法分组采用直线加速器对Sprague-Dawley大鼠进行全脑照射,剂量分别为10Gy、20Gy、30Gy、40Gy,并设未照射组为对照。在照射前及照射后7d,20d,60d分别进行Morris水迷宫实验,分析各组大鼠行为学检测结果,采用平均逃避潜伏期和搜索策略两个指标评价大鼠学习记忆能力。同时观察各组脑组织病理变化。结果20Gy、30Gy、40Gy剂量组与对照组及10Gy组照射后不同时间点平均潜伏期和搜索策略差异有显著性(P<0.05)。20Gy组在放射后7d、20d平均逃避潜伏期[(66.57±11.49)s、(51.30±12.45)s]和搜索策略得分[(15.64±2.14)分、(19.64±2.28)分]明显下降,60d时潜伏期[(40.05±10.98)s]和搜索策略得分[(26.42±2.59)分]有所恢复,30Gy和40Gy组在放射后60d仍没有恢复。30Gy组和40Gy组病理检查显示神经元萎缩变性,白质梳松。结论学习记忆能力检测可作为判断放射性脑损害的敏感指标,20Gy以上剂量放射线照射可降低大鼠学习记忆能力。更多还原

【Abstract】 ObjectiveTo setup radiation brain injuries model with rat and study the effects of radiation on learning and memory ability of rat under different dose of radiation.MethodsSprague-Dawley rats were grouped according to radiation dose to 10Gy group, 20Gy group, 30Gy group, 40Gy group radiated by linear accelerator and control group were used. Before radiation and 7, 20, 60 days after radiation, Morris maze test were taken to study the learning and memory ability of rats in each group. Average escape latency(AEL) and search strategy(SS) were scaled and analyzed.Pathology examinations were taken in every group. ResultsNo statistic differences of AEL and SS were found in each group before radiation. The learning and memory ability of rats in 20Gy group, 30Gy group, 40Gy group were impaired more than that of 10Gy group and control group(P<0.05). The scales of AEL in 20Gy group were decreased after 7, 20 days [(66.57±11.49)s,(51.30±12.45)s] and the scales of SS(15.64±2.14、19.64±2.28)and recovered after 60 days(AEL, 40.05±10.98s, SS, 26.42± 2.59 )but no recoveries were found in 30Gy and 40Gy group after 60 days of radiation. Neurons were atrophic degenerated and whiter matter were loosen in 30Gy group and 40Gy group but not in other groups. ConclusionLearning and memory ability examination can be used as a sensitive method to evaluated radiation brain injuries and radiation can decrease the learning and memory ability of rat with the dose exceed 20Gy.更多还原