青霉素诱发发育期大鼠反复惊厥对学习记忆功能的远期影响

目的 建立发育期大鼠青霉素点燃模型,观察青霉素点燃幼龄大鼠模型的空间学习记忆能力.方法 生后29 d(P29) 的SD大鼠随机分为青霉素点燃实验组(RS,n=22)及生理盐水对照组(NS,n=10).RS组隔日腹腔注射青霉素560万U/kg体质量,连续6次,NS组以同样方法腹腔注射生理盐水.于末次惊厥后进行脑电记录.分别于P51～P56、P81～P84、P92～P95 进行3次Morris水迷宫实验,检测大鼠的学习和记忆功能.结果 ①皮层脑电图显示RS组明显的棘波和尖波.②逃避潜伏期:第1次Morris水迷宫各组潜伏期均呈逐渐下降趋势,但RS组第5天潜伏期(29.57±18.52)s]明显高于NS组(8.21±4.86)s],差异有显著性(t=3.14,P=0.014＜0.05);RS组第2次迷宫测试中第1天(46.31±17.91)s]明显高于NS组(21.21±18.25)s],差异有显著性(t=2.68, P=0.019＜0.05);第3次水迷宫第2天的潜伏期值(26.87±21.74)s仍明显高于NS组(7.85±7.11 )s,差异有显著性(t=2.34, P=0.045＜0.05).③记忆实验:三次记忆测试平台象限路径与总路径之比,RS组第1次(0.16±0.07)s;第2次(0.22±0.07)s;第2次(0.20±0.06)s]均明显低于NS组第1次(0.31±0.13)s;第2次(0.34±0.05)s;第3次(0.29±0.07)s],差异有显著性(P＜0.05).结论 青霉素诱导的发育期反复惊厥能够对学习和记忆功能产生远期的损害.

Long-term effects of penicillin-induced developmental seizures on learning and memory capacity of rats

Objective To explore the long-term effects of penicillin-induced developmental seizures on learning and memory capacity of rats. Methods The rats were randomly divided into the recurrent-seizure group (RS) and the control group. Penicillin was used to induce seizure attack. At postnatal day 29(P29), the recurrent seizures induced once two day for consecutive eleven days. At P51～P56,P81～P84,P92～P95, Morris water-maze test were performed to evaluate spatial learning and memory capacity. Results ①Vertex sharp transient wave and sharp wave were detected in RS group by electrocorticogram. ②Escape latency:in the first Morris water-maze test, there was a decreasing trend of escape latency in two groups, and the escape latency of RS group in d5 was much longer than that of control group(P＜0.05); the difference of escape latency in d1 of the second and d2 of the third Morris water-maze tests were also significantly different compared with that of control.③Memory test:as for the value of distance in origin platform quadrant to total distance, the RS group seemed better than the control group in three maze tests(P＜0.01). Conclusions Recurrent developmental seizures induced by penicillin could cause long-term effects on learning and memory.