Abstract:OBJECTIVE: To study the expression of phosphorylated-ERK1/2(p-ERK1/2)MAPK in the prefrontal lobe cortex (PFC), hippocampus (HP) and nucleus accumbens (Acb) in mice exposed to heroin in the uterus, and elucidate whether ERK MAPK signal transduction pathway participates in neurobehavioral teratogenicity induced by maternal heroin abuse. METHODS: Animal model was established by subcutaneous administration of diacetylmorphine (10 mg/kg?d) to pregnant BALB/c mice on embryonic days 9-18, and their offspring were assigned to heroin and normal saline groups according to the maternal treatment. P-ERK1/2 expression in the PFC, HP and Acb were detected by RT-PCR and Western blot. RESULTS: The heroin group had body weights similar to the normal saline group after birth. There were no significant differences in the p-ERK1/2 expression in the PFC, HP and Acb between the two groups. CONCLUSIONS: Prenatal exposure to 10 mg/kg heroin altered neither the body weight nor the general development in mice. The ERK1/2 MAPK signal pathway might not be involved in the neurobehavioral teratogenicity induced by prenatal heroin exposure. [Chin J Contemp Pediatr, 2009, 11 (4):306-309]