急性应激和急性吗啡暴露对不同年龄大鼠空间记忆的影响

Effects of Acute Stress and Acute Morphine Exposure on Spatial Memory in Rats of Different Ages

目的:观察急性应激和/或急性吗啡暴露(2mg/kg)对4周龄和10周龄大鼠记忆的影响。方法:建立平台应激模型,运用Morris水迷宫来观察急性应激和急性吗啡暴露对4周龄和10周龄大鼠空间记忆的影响。结果:①4周龄组:急性应激组、吗啡组及急性应激加吗啡组在目标象限停留的时间均比对照组短(P<0.05)。②10周龄组:急性应激组在目标象限停留的时间比对照组短(P<0.05)。吗啡组及急性应激加吗啡组与对照组相比差异无显著性(P>0.05)。③两个年龄段的比较:10周龄吗啡组、急性应激加吗啡组在目标象限停留的时间均比4周龄要长(P<0.05)。而急性应激组和对照组这两个年龄段分别比较差异无显著性(P>0.05)。两个年龄组中各组大鼠的运动速度分别与对照组相比差异无显著性(P>0.05)。结论:①急性平台应激损害4周龄和10周龄大鼠的记忆,但没有明显年龄差异;②急性吗啡暴露(2mg/kg)对4周龄大鼠的记忆有损害作用,而对10周龄的记忆没有影响,存在年龄差异。③急性应激加吗啡损害了4周龄大鼠的记忆保持,而对10周龄大鼠的记忆保持无影响,存在年龄差异。

Objective： To study the effects of acute stress and acute morphine exposure （2mg/kg） on spatial memory in 4-or 10-week-old rats. Methods： Morris water maze was used to assess the effects of acute stress （established by elevated platform stress protocol） and acute morphine exposure on spatial memory in 4-or 10-week-old rats. Results： ① 4-week- old rats： Rats of acute stress group, acute stress and morphine group and morphine group spent significantly less time in the target quadrant than that of control group, respectively （P〈0.05）. ②10-week-old rats： Rats of acute stress group spent significantly less time in the target quadrant than that of control group （P〈0.05）. Compared with control group time in the target quadrant did not differ in acute stress plus morphine group, morphine group （P 〉0.05）. ③Comparison between 10- week-old rats and 4-week-old rats：10-week-old rats in morphine group, acute stress plus morphine group spent significantly more time in the target quadrant than that of 4-week-old rats in the same groups, respectively （P〈0.05）.Time in the target quadrant did not differ in acute stress group and control group between 4-week-old rats and 10-week-old rats （P 〉 0.05）. Swimming speed did not differ between all groups of 4-or 10-week-old rats （P 〉0.05）. Conclusion： ①Aeute stress induced impairment of memory retention in 4-or 10-week-old rats, respectively; but it did not differ between ages. ②Acute morphine exposure at the dose of 2mg/kg induced impairment of memory retention in 4-week-old rats and had no effect on memory retention in 10-week-old rats. It showed difference between two age groups. ③Aeute stress plus morphine induced impairment of memory retention in 4- week-old rats and had no effect on memory in 10-week-old rats. It showed difference between two age groups.