侧脑室置管对大鼠长时记忆提取功能的影响

The influence of intracerebroventricular cannulation on rats＇ long - term memory function

目的观察侧脑室置管技术对大鼠长时记忆提取功能的影响。方法SD大鼠134只，2只在侧脑室置管后用于观察定位是否准确，其余大鼠进行水迷宫训练后随机编入对照组（n=12）、未置管组（n：60）、置管组（n=60）；未置管组及置管组术后分别于后6、12、24h、3、7d再次进行水迷宫测试，记录逃避潜伏期、穿越平台次数及在目标象限停留时间并绘制轨迹图；水迷宫测试后取脑组织，行尼氏染色以观察尼氏体形态学变化，酶联免疫吸附试验（EHSA）检测海马组织大鼠脑源性神经营养因子（BDNF）含量。结果未置管组较对照组差异无统计学意义（P〉0．05），置管组术后6h逃避潜伏期较对照组延长[（37．84±24．32）s比（26．78±17．38）s，P〈0．05]，穿越平台次数及在目标象限停留时间减少[（2．83±1．34）次比（4．72±1．80）次、（23．74±8．30）s比（29．67±13．93）s，P〈0．05]，轨迹图较其余各组杂乱且分散；尼氏染色示置管组神经元尼氏体与对照组差异无统计学意义（P〉0．05）；置管组与对照组的BDNF含量在置管后3、7d比较差异无统计学意义[（171．64±11．16）pg／ml比（167．65±11．04）pg／ml、（162．33±9．14）pg／ml比（167．65±11．04）pg／ml，P〉0．05]。结论置管后大鼠的长时记忆提取功能短暂下降后可很快恢复并维持在正常水平。

Objective To investigate the intracerebroventricular cannulation on rats＇ long- term memory function. Methods 134 SD rats were used, of which 2 rats were assigned to observed on whether positioning accurate after the Intracerebroventricular cannulation, others were performed Morris water maze and randomly divided into control group （ n = 12）, non - cannulated group （ n = 60） and cannulated group （n =60）. After operative procedure, Morris water maze was performed again in 6 h, 12 h, 24 h, 3 d, 7 d, it was recorded with the escaping latency, frequency crossing the platform area and the duration in the target quadrant after ridding the platform, trajectory chart was also depicted. After Morris water maze, brain tissue were obtained, and after Nissl＇ s staining, variation of Nissl＇ s morphology was observed; the content of brain derived neurotrophic factor （BDNF） in hippocampus was tested by enzyme linked immu- nosorbent assay （ELISA）. Results No differences between control group and non - cannulated control group （P 〉 0. 05 ） ; The escaping latency of cannulated group was prolonged after intracerebroventricular cannulation in 6 h [ （37. 84 ± 24. 32） s vs. （26. 78 ± 17.38） s, P 〈 0.05 ], and frequency crossing the platform area and the duration in the target quadrant were decreased [ （2. 83 ± 1.34） times vs. （4. 72 ± 1.80） times, （23.74 ± 8. 30） s vs. （29. 67 ± 13.93） s, P 〈 0. 05 ], trajectory chart was cluttered and dispersed compared to other groups. There was no significant difference of Nissl body between the control group and the cannulated group ＇after intracerebroventrieular cannulation （ P 〉 0. 05 ） ; the content of BDNF was no difference between cannulated group and control group in 3, 7 d after intracerebroventricular cannu- lation [ （ 171.64 ± 11.16） pg/ml vs. （ 167. 65 ± 11.04） pg/ml, （ 162. 33 ±9. 14） pg/ml vs. （ 167.65 ± 11.04） pg/ml, P 〉 0. 05 ]. Conclusion Rats＇ long- term memory function could decrease temporarily and quickly recover and maintain the normal level after Intracerebroventricular cannulation.