Effects of oral Morphine on the development of olfactory bulb in rat embryo

Opioids abuse is a nationwide problem in our country. Regarding the potential of these drugs in crossing placenta they can cause many defects in fetuses of human and also animals. In the present study, the effects of maternal Morphine consumption on olfactory bulb development in rats have been investigated. Female Wistar rats (weight: 250-300g) were crossed with male rats and the zero time of pregnancy was detected. Existence of vaginal plug and also sperm in vaginal smear were indicators of mating and pregnancy. Experimental group received 0.05 mg/ml of Morphine in drinking water daily. On embryonic day 19, pregnant animals were anesthetized by Chloroform and embryos were taken out surgically. Weight of the embryos was determined by a digital balance and their length (Crown-Rump, Frontal-Occipital, Biparietal, Abdominal-Transfer and Anterior-Posterior diameters) were determined by a caliper. Then embryos were fixed in Formalin 10% and tissues were processed and sectioned and stained in Hematoxilin & Eosin and Bielschwosky staining methods. These sections were investigated for olfactory bulb development by MOTIC software and light Microscope. Data was analyzed using t-test. The decrease in embryonic weight and their diameter for experiment group was significant. In microscopic study, the increase in thickness of mitral layer and the decrease in total number of Tufted, Mitral and Granular cells in experimental group were significant. This study showed that oral Morphine consumption leads to olfactory bulb defects.