THE EFFECTS OF PRENATAL MORPHINE EXPOSURE ON RETRIEVAL OF SPATIAL MEMORY IN RATS

Background and Opioids such as morphine are over used during pregnancy. These substances can probably induce long–term behavioral and psychological alterations (particularly learning and memory alterations) in exposed infants. This study was conducted to determine the effects of prenatal morphine exposure on the retrieval of spatial memory in rats. Methods and Materials: In this experimental research, 18 pregnant wistar rats were assigned into three groups: The control group, the saline group and the morphine group. The control group received nothing but the saline and morphine groups received subcutaneus 0.5 mg saline and morphine (5mg/kg for 3 days and 10 mg/kg for 5 days) respectively, twice a day on 11-18 gestational days. After birth, 30 exposed pups of 90 days were trained in an 8-arm radial maze apparatus and their retrieval of spatial memory was assessed 48 hours and 1 week after training. The injection of morphine during pregnancy can seriously impair the retreival of spatial memory in childeren so that correct responses in the morphine- group rats were far less than correct responses in other groups, on the retrieval days (48 hours and 1 week after training). According to the findings, prenatal morphine exposure can impair the retrieval of spatial memory.