The effect of infrasound of low sound pressure level on the expression of glial fibrillary acidic protein in hippocampus of mice

Objective:To study the expression of glial fibrillary acidic protein(GFAP) in hippocampus of mice after exposure to infrasound of low sound pressure level for different times. Method:Sixty BALB/C male mice were randomized into control group and infrasound exposure group. Mice of the infrasound exposure group were exposed to infrasound of low sound pressure level (8—12Hz, 60—80dB) generated by infratonic 9 instrument, 1h/d for1,7,14,21 and 28 days. Mice of control group were treated as the infrasound group except for the infrasound exposure. Brains of mice were removed and immunofluorescent staining method was used to detect the expression of GFAP in hippocampus right after the treatment. Result:The expression of GFAP-positive cells in hippocampus showed after once exposure there was no significant change (62.9±3.0), after exposure for 7 days decreased(60.5±8.0), after exposure for 21 days reached to the least(56.3±5.3)(P0.05), after exposure for 28 days increased to normal level(59.2±9.7)(P0.05). Conclusion:Infrasound of low sound pressure level generated by infrasound instrument could inhibit the activation of GFAP-positive astrocytes in hippocampus of mice, which might provide the theory basis for the clinical therapy of infrasound.