Abstract: ObjectiveTo observe the relationship between astrocytes and neurons in rat's medulla oblongata after exposed to 8Hz, 90dB/130dB infrasound for different times. MethodsRats were exposed to 8Hz, 90dB/130dB infrasound for 2 hours per day.At the 1st,7th,12th,21th and 28th day, the expression of glial fibrillary acidic protein (GFAP) and Fos in medulla oblongata were detected using double-labling immunohistochemical method.Results GFAP-positive astrocytes and Fos-positive neurons were increased after exposure for one time. They showed similar topographic localization and formed close relationship. Their number increased as the exposure times increasing, and decreased gradually after 14 days. The reaction of 130dB group was stronger than that of 90dB group.Conclusions 8Hz, 90dB/130dB infrasound can activate both astrocytes and neurons in rats' medulla oblongata which might participate and regulate the response to infrasound.

Key words: infrasound, hippocampus, glial fibrillary acidic protein (GFAP), Fos