Abstract: Objective To explore the role of brain-derived neurotrophic factor (BDNF) in pathogenesis of autism. Methods 12.5 d pregnantWistar rats were injected sodium valproate (VPA) 600 mg/kg or normal saline (NS). Their newborn rats were observed ethologically.The expression of BDNF was measured in their temporal cortex with immunohistochemical stain. Results Compared with NS group, VPAgroup expressed less body mass (P<0.05), eyes opening delay (P<0.05), poorer coordination response (P<0.05), slower taxis response (P<0.05). The number of social behavior decreased (P<0.05), latency increased (P<0.05), duration shortened (P<0.05), repetitive activities increased(P<0.05). Purkinje cells reduced in cerebellum. The expression of BDNF increased significantly in temporal cortex 1 d, 7 d and 14 dpostnatally (P<0.01), but decreased 35 d and 49 d postnatally (P<0.01). Conclusion BDNF plays a role in the pathogenesis of autism.

Key words: autism, brain-derived neurotrophic factor, sodium valproate, rats