Effects of infrasound on learning and memory and the expression of ryanodine receptor in hippocampi and temporal cortex of rats / 中华物理医学与康复杂志

ABSTRACT

Objective To investigate the effects of 8Hz infrasound on spatial learning ability of rats and its the underlying mechanism. Methods Forty male SD rats were randomly divided into a control group and an experiment group (consisting of the 8Hz, 90dB, 100dB and 130dB subgroups). The experimental subgroups were exposed to 8Hz, 90dB, 100dB or 130dB infrasound for 2 hours daily, respectively, for a total of 6 days. All of the rats were taken out of the infrasonic depot once a day and given Morris maze training. And at last the brain of the rats were harvested and treated with immunohistochemical staining for detection of ryanodine receptor (RyR). The content of RyR in hippocampi and temporal cortex were detected under an optical microscope. Results The rats in the 8Hz, 90dB, 100dB and 130dB subgroups showed prolonged latency in Morris training ( P =0.010, P =0.001 and P = 0.000 ). The hippocampi and temporal cortex of rats in 8Hz, 90dB, 100dB and 130dB subgroups showed less positive neurons of RyR ( P =0.000). There was a negative correlation between the latency period of rats finding the hidden platform and the content of RyR in hippocampus and temporal cortex. Conclusion Infrasound of 8Hz, 90dB, 100dB and 130dB could decrease the spatial learning ability of rats, and this was possibly related to the reduce of RyR in hippocampus and temporal cortex.