Effect Of Morphine Addiction And Withdrawal In Parents Prior To Mating On Social Interaction And Expression Of Oxytocin In Paraventricular Nucleus Of Adult Offspring Rats

Objective To investigate the effects of morphine addiction and withdrawal in parents prior to mating on social interaction and expression of oxytocin in paraventricular nucleus in adult offspring rats.Methods The morphine addiction of rats were used according to previously described.After withdrawal for 21days,the female and male rats were mated and divided into four groups;group 1:addicted males + addicted females;group 2:addicted males + females that received 0.9% normal saline;group 3:males that received 0.9%normal saline + addicted females;group 4:males that received 0.9%normal saline + females that received 0.9%normal saline.After birth of offspring,we observed the parental maternal behaviors,which including the latency period and total time of retrieve pups,the latency period and total time of mother licking and lactating pups,and the latency period of building nest. The general conditions of offsprings were observated.The social interaction experiment was carried out by 8 weeks age of the offspring to test the socialability.The oxytocin expression in paraventricular nucleus were observed by immunohistochemistry technique.Results Motherhood behaviors,the latency to retrieve pups of group 1 femal rats was obvious higher than group 2,3 and 4,and there were no difference of the total time of retrieve pups between groups;the latency to licking pups of the group 1 femal rats was longer than group 2,3,4,the total time of licking pups of group 1,2,3 femal rats was shorter than that of group 4;the lactation latency and total time were no obvious difference between groups;the latency period of building nest of group 4 femal rats was longer than group 3,that of group 1 femal rats building nest was longer than group 2.There were no differences of the general observation in offsprings among groups.The sociability experiment showed that both male and female offspring of group 1,2,3 interacted less time with inanimate target than that of group 4,male offspring of group 1,2,3 spent less time with social target than group 4,there were no differences among the female offspring of 4 groups when they interacted with social target in the first 10 minutes.In the following 10 minutes,both male and female offspring of group 1,2,3 interacted less time with social novelty target than that of group 4,similarly to interacted time with familiar target.Immunohistochemistry results showed that the number of oxytocin immunoreactive positive cell in paraventricular nucleus of group 1,2,3 either male or female offspring were less than that of group 4.Conclusion There were maternal care defect partially after morphine addiction and withdrawal in parents prior to mating,There were no differences of the general observation in offsprings among groups.But that parents experienced the matter of morphine addiction and withdrawal before mating may may cause sociability deficiency and affect expression of oxytocin in PVN of adult offspring rats.