ABSTRACT
Objective To investigate the effect of 8 Hz infrasound on the expression of brain derived neurotrophic factor(BDNF)in the rat hippocampus.Methods Forty-eight Sprague-Dawley rats were randomly divided into groups to be exposed to 90,100 and 130 dB infrasound,and a control group(n=12).All the animals in the infrasound exposure groups were exposed to 8 Hz infrasound at the planned intensity for 2 hours daily for 4 weeks.The rats of the control group were treated identically except that the infrasound amplitude was 0 dB.The animals were sacrificed and their brains were examined at the end of the 4-week infrasound exposure.Western blotting was used to detect the expression of BDNF protein,and in situ hybridization(ISH)was used to observe the distribution of BDNF mBNA in the hippocampus.Results Eight Hz infrasound induced down-regulation of BDNF protein in the hippocampus,with volume-dependent characteristics.ISH showed that BDNF mRNA was distributed widely in the hippocampus.After exposed to infrasound,BDNF mRNA in the hippocampus decreased,especially in the dental gyrus.Conclusion Eight Hz infrasound can down-regulate the expression of BDNF in the hippocampus,especially in the dental gyrus.