Effect of morphine addiction and withdrawal in parents prior to mating on the anxiety-like behavior and spatial learning-memory in adult offspring rats

Abstract

Objective To study the impact of morphine addiction and withdrawal in parents prior to mating to the anxiety-like behaviour and spatial learning-memory in adult offspring rats. Methods 24 rats(12 female and 12 male) were used.6 males and 6 females were intraperitoneally injected with morphine twice a day for 10 days in ascending dosage schedule,accordingly. The rest of rats were injected with saline of the same volume. Twenty one days after morphine withdrawal,rats were mated. Then each one male with one female were housed(coupled) per cage as four groups for coupling:addicted males + addicted females(Group 1);addicted males + saline females(Group 2);saline males + addicted females(Group 3);saline males+ saline females(Group 4).When the offspring was 8 weeks of age,the anxiety-like behavior and spatial learning-memory were assessed in the elevated-plus maze test, the open-field test and morris water maze respectively.Results Compared with the female and male's offspring in group 4[(10.41±2.64,9.32±1.63)％],the female and male's offspring in group 1,2,3 exhibited the percent of time spent in open arms[(2.49±0.91, 0.45±0.10)％,(3.34±1.12,5.51±1.60)％,(3.15±0.52,2.09±0.70)％] were reduced obviously in the elevated plus maze( P 0.05). Conclusion These findings suggest that parents experiencing morphine addiction and withdrawal prior to mating can result in the offsprings anxiety-like behavior,but have no obvious effect on spatial-memory learning. Key words: Morphine addiction; Withdrawal; Offspring; Anxiety; Learning- memory