8Hz次声对大鼠海马和颞叶皮层5-HT表达的影响

Effect of 8 Hz infrasound on expression of 5-HT in rats' hippocampus and temporal cortex

目的研究 8Hz ,90dB、10 0dB、13 0dB次声对SD大鼠海马及颞叶皮层 5 HT表达的影响。方法 14 0只雄性SD大鼠随机分为正常对照组及 8Hz ,90dB、10 0dB、13 0dB次声作用 1、7、14、2 1、2 8、3 5、42d组共 2 8组 ,每组 5只。试验组按组别分别暴露于次声仓中 ,每日 2h ;对照组亦暴露于次声仓 ,每天 2h ,但不予次声作用。最后一次次声作用结束后立即取脑组织并进行 5 HT免疫组织化学染色 ,光学显微镜下观察海马及颞叶皮层 5 HT表达的变化。结果次声作用组大鼠脑组织海马及颞叶皮层 5 HT阳性纤维均较对照组明显减少 (均为P <0 .0 1) ,90dB组、10 0dB组以 2 8d时减少最为明显 ,且 10 0dB组的阳性纤维数量较 90dB组少 ;13 0dB组以 2 1d时减少最为明显。各实验组的阳性纤维数量在此后均有所增加。结论 8Hz ,90dB、10 0dB和 13 0dB次声可引起大鼠海马及颞叶皮层 5 HT表达减少 ,其变化规律与次声作用参数有关 ,相同作用时间下 ,13 0dB组的变化较 10 0dB及 90dB组明显。

ObjectiveTo study the effect of 8 Hz infrasound on the expression of 5-hydroxytryptamine (5-HT) in rats' hippocampus and temporal cortex.Methods140 male SD rats were randomly divided into the control group, and experimental groups that exposed to infrasound of 8 Hz, 90 dB, 100 dB and 130 dB for 1, 7, 14, 21, 28, 35, 42 days. Experimental groups were exposed to infrasound for 2 hours each day. The control group was only placed in the infrasonic storehouse but without infrasound. Rats' brains were taken as soon as the exposure finished and strained by immunohistochemistry. The content of 5-HT in hippocampus and temporal cortex was detected under an optical microscope.ResultsInfrasound groups had less expression of 5-HT in hippocampus and temporal cortex than the control group ( P<0.01 ), and the least were at the 28th day for 90 dB and 100 dB groups and the 21st day for 130 dB group. Then the expression of 5-HT had an increase in each group.ConclusionThe deceased expression of 5-HT in rats' hippocampus and temporal cortex could result from infrasound of 8 Hz. Rules of change are related to the parameter of infrasound and the 130 dB 8 Hz infrasound can induce greater changes compared with that of 100 dB and 90 dB.