Effect of intrauterine morphine sulfate exposure on cerebellar histomorphological changes in neonatal mice.

Neurotoxic effects of morphine sulfate in adult cerebellar cortex and neonatal cerebral cortex have been studied in animal models. This study was done to determine the neurotoxic effects of prenatal morphine exposure on the histo-morphological changes of cerebellar cortical layer and Purkinje cells in mice neonates. In this experimental study 30 female mice were randomly allocated into cases and controls. In the case group, animals received morphine sulfate 10 mg/kg/body weight intraperitoneally for 7 days. After mating, dams received morphine sulfate 10 mg/kg/body weight intraperitoneally for 20 days of gestation. Animals in the control group received normal saline. On the day of delivery (P0), the cerebella of six neonates for each group were removed and stained with cresyl violet. Quantitative computer-assisted morphometric study was done on the cortical layer of the cerebellum. Morphine exposure caused a non-significant increase in fetal weight in the case group. Purkinje cells in cases were decreased in comparison with controls (p < 0.05). Histomorphometric examination revealed that the thickness of Purkinje and internal granular layers of the cerebellar cortex decreased in the morphine-exposed group (p < 0.05). This study revealed that morphine administration before and during pregnancy can cause Purkinje cell loss and reduction of thickness of the Purkinje and internal granular layer of the cerebellar cortex and size of Purkinje cells in neonatal mice.