普萘洛尔对条件性恐惧大鼠恐惧记忆保持与海马CA3区神经元形态的影响  

Effect of propranolol on retention of fear memory and morphology of neurons in hippocampal CA3 area of rats with conditioned fear

作　　者：田玉娥[1,2,3] 刘江杰[1,2] 张燕[1] 李敏[1] 张永亮[3] 

机构地区：[1]第三军医大学护理系心理学教研室,重庆400038 [2]武警新疆兵团指挥部医院,乌鲁木齐830063 [3]武警天津医学院病理学教研室,天津300162

出　　处：《第三军医大学学报》2011年第12期1207-1210,共4页Journal of Third Military Medical University

基　　金：国家自然科学基金(30670712);重庆市自然科学基金(CSTC2009BB5014)~~

摘　　要：目的研究不同时间给予普萘洛尔对条件性恐惧大鼠恐惧记忆保持及海马CA3区神经元形态的影响。方法成年雄性SD大鼠24只,采用声音结合强烈足底电击建立大鼠条件性恐惧模型。大鼠建模成功后分为对照组(不给药,只在相应时间点进行恐惧水平测验)、立即给药组(15 min内给予普萘洛尔)和24 h后给药组(24 h后给予普萘洛尔),每组8只。给药组在建模后前3 d每天恐惧测试前给予普萘洛尔后再检测各组大鼠条件性恐惧记忆水平,于第20天完成恐惧记忆测试后处死大鼠,用高尔基染色法检测大鼠海马神经元形态和数量,电镜观察海马超微结构的变化。结果①条件性恐惧建模后,第1天3组大鼠恐惧水平差异无统计学意义(P>0.05);第2、3、20天时,两给药组大鼠恐惧水平逐渐降低,且3组大鼠在同一时间点恐惧水平差异有统计学意义(P<0.05,P<0.01),立即给药组恐惧水平最低,对照组恐惧水平最高。建模后第20天,对照组大鼠恐惧水平仍然较高。②建模后第20天,两给药组海马神经元CA3区锥体细胞数量[立即给药组(4.94±2.67)个,24 h后给药组(4.65±1.98)个]均大于对照组[(3.58±2.03)个],其中立即给药组明显大于对照组(P<0.05)。③电镜显示对照组海马CA3区超微结构出现异常改变,而两给药组超微结构变化不明显。结论条件性恐惧水平与海马结构发生的形态学异常变化有关,而早期应用β受体阻断剂普萘洛尔阻断β受体抑制去甲肾上腺能神经系统活性,可以在一定程度上降低条件性恐惧、减轻海马神经元结构功能损害。Objective To study the effect of propranolol on retention of fear memory and morphology of neurons in hippocampal CA3 area of rats with conditioned fear.Methods A rat model of conditioned fear was established.Twenty-four male adult SD rats were randomly divided into control group（which received no drug treatment with their fear level measured at the corresponding time points）,immediate drug treatment group（which received propranolol treatment 15 min after the model was established）,and 24 h drug treatment group（which received propranolol treatment 24 h after the model was established）,8 rats in each group.Conditioned fear memory levels in rats of drug treatment groups were measured daily for 3 d before the model was established and after propranolol was given.The rats were killed on day 20 after measurement of their fear memory levels.Morphology,number and ultra-structure of neurons in hippocampi were observed under a transmission electron microscope.Results No significant difference was observed in fear memory levels among the 3 groups 1 d after the model was established.The fear memory levels decreased gradually in two drug treatment groups 2,3 and 20 d after the model was established and were significantly different among the 3 groups at the same time point（P〈0.05 or P〈0.01）.The fear memory level was the lowest in immediate drug treatment group and the highest in control group,was still rather high 20 d after the model was established,and decreased gradually in two drug treatment groups 2,3,and 20 d after the model was established.The number of pyramidal cells in hippocampal CA3 area was significantly higher in two drug treatment groups than in control group（4.94±2.67 and 4.65±1.98 vs 3.58±2.03,P〈0.05）.Abnormal changes of ultra-structure were observed in hippocampal CA3 area of control group under a transmission electron microscope after the model was established,but no significant difference was seen between the two drug treatment groups.Conclusion Conditioned fear memory level is

关 键 词：条件性恐惧记忆 普萘洛尔 海马 神经元 

分 类 号：R338.26[医药卫生—人体生理学] R338.64[医药卫生—基础医学]