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Objective:To observe the effect of electroacupuncture at the Baihui acupoint on learning and memory ability and on the calmodulin kinase (CaMK)Ⅱ-Tau protein signal pathway in rats exposed to infrasound, and to explore its mechanism.Methods:Forty-eight Sprague-Dawley rats were randomly divided into a blank group, an infrasound group, a Baihui group and a non-acupoint group, each of 12. The rats in the blank group were placed in an infrasound chamber without infrasound for 2 hours daily. Those in the other 3 groups were exposed to 8Hz, 130dB infrasound in the chamber for 2 hours daily for 7 consecutive days. The rats in the Baihui and non-acupoint groups were given electroacupuncture within 2 hours after the infrasound exposure at the Baihui acupoint or elsewhere respectively. The rats in the blank and infrasound groups were given the same grasping and fixation, but no electroacupuncture. On the 6th and 7th day of intervention, Morris water maze positioning and navigation experiments and spatial exploration experiments were used to quantify the rats′ spatial learning and memory ability. Nissl staining was used to observe any changes in the morphology of the neurons in the hippocampus of 6 rats in each group. The expression of phosphorylated calmodulin-dependent protein kinase II (P-CaMKⅡ) and phosphorylated Tau protein (P-Tau) in the hippocampus was also documented using western blotting.Results:After 6 or 7 days the average escape latency of the rats in the infrasound group was significantly longer than the blank group′s average. Platform quadrant time and distance ratios and the number of times crossing the platform area were also significantly lower. Compared with the infrasound group, the average escape latency of the Baihui group was significantly shorter, with the platform quadrant time and distance ratios and the number of times crossing the platform area significantly higher. After 7 days, the damage to hippocampal neurons among the rats in the infrasound group was significantly aggravated and the number of neurons was reduced significantly compared with the blank group. Compared with the infrasound group, significantly fewer neurons in the hippocampus were damaged in the Baihui group and the number of neurons had increased significantly. After the intervention the levels of P-CaMKⅡand P-Tau protein in the infrasound group had increased significantly compared with the blank group, but those levels in the Baihui group were significantly lower, on average.Conclusion:Electroacupuncture at the Baihui acupoint can improve the learning and memory ability of rats exposed to infrasound, and has some protective effect against infrasound brain damage. That may be due to its inhibiting Tau protein hyperphosphorylation in the hippocampus by reducing CaMKⅡ activity.
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Objective To investigate the effect of low sound pressure level infrasound on che-mokine-mediated inflammatory response in spinal cord in rats with neuropathic pain.Methods Seven-ty-two healthy male SD rats were randomly divided into sham operation group (group Sham),neuro-pathic pain group (group NP)and low sound pressure level infrasound intervention group (group LNP),24 in each.The sciatic nerve injury models were established.3 d after the model constructed, the rats in group LNP started to receive low sound pressure level infrasound therapy,4 h per day, continued for 21 d.1 d before surgery (T0 )and 3 d after surgery (T1 ),all rats were detected me-chanical paw withdrawal threshold (MWT).Respectively,after treated for 7 d (T2 ),14 d (T3 )and 21 d (T4 ),eight rats were randomly selected from each group and their MWT was measured.The ex-pressions of MCP-1 mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6 mRNA in spinal cord in rats were detected using quantitative PCR,the expressions of MCP-1 protein and CCR2 protein in spinal cord in rats were detected by using Western blot.Results MWT in groups NP and LNP at T1-T4 was lower than that of group Sham,and that in group LNP at T3-T4 were higher than that of group NP,respectively (P <0.05).Compared with group Sham,the relative expression levels of MCP-1 mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6 mRNA in spinal cord tis-sues in groups NP and LNP at T2-T4 were increased (P <0.05);compared with group NP,the rela-tive expression levels of MCP-1 mRNA,CCR2 mRNA,TNF-αmRNA,IL-1βmRNA,and IL-6 mR-NA in spinal cord were decreased in group LNP at T3-T4 (P <0.05 ).Western blot analysis showedthat the relative expression levels of MCP-1 protein and CCR2 proteinin spinal cord in groups NP and LNP at T2-T4 were higher than that of group Sham,while relative expression levels of MCP-1 protein and CCR2 proteinin spinal cord in group LNP at T3-T4 were lower than that of group NP. Conclusion The low sound pressure level infrasound could effectively reduce neuropathic pain in rats, possibly via inhibiting chemokine-mediated cascade inflammatory reaction.
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@#Objective To study the effect of infrasound on expression of calmodulin-dependent protein kinase II (CaMKII) and tau pro-tein in hippocampus of rats. Methods Fifty-six male Sprague-Dawley rats were randomized into control group (n=8), 1-day group (n=8), 7-day group (n=8) and 14-day group (n=32), and the 14-day group was subgrouped as 1-hour, 6-hour, 24-hour, 48-hour subgroups, naming after the time after infrasound exposure, 8 in each subgroup. All the test groups were put in an infrasound field with 8 Hz, 130 dB for 2 hours daily, while the control group was put in the infrasound instrument without infrasound exposure for 2 hours daily. The expression of pT286-CaMKII and tau protein in hippocampus was detected with immunohistochemisty, Western blotting and enzyme-linked immunoabsor-bent assay. Results The expression of pT286-CaMKII was the most in 14-day group (F>14.912, P<0.001), as well as the expression of tau pro-tein (F>36.229, P<0.001), and secondary in 7-day group (P<0.05). For 14-day group, the expression of tau protein was the most in 1-hour and 6-hour subgroups, and dropped down in 24-hour subgroup, although more than that in the control group (P<0.05). Conclusion Exposure of 8 Hz, 130 dB infrasound may induce phosphorylation of CaMKII and tau protein, and the expression of tau protein in hippocampal cells in rat, which may disturb their learning and memory function.
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<p><b>OBJECTIVE</b>The objective was to observe damage of hippocampus in rats after exposure to infrasound, and to assess HSP70 expression in hippocampus.</p><p><b>METHODS</b>SD rats in the experimental group were exposed to 140 dB (8 Hz) infrasound for 2 h per day for 3 days. The morphology of the hippocampus was examined by transmission electronic microscopic (TEM). Cell apoptosis was observed by TUNEL staining at 0 h, 24 h, 48 h, and 2 w after exposure. HSP70 expression was detected by immunohistochemistry (IHC) and Western blotting (WB).</p><p><b>RESULTS</b>TEM showed that hippocampus was significantly damaged by exposure, and exhibited recovery 1 week after exposure. The TUNEL data showed that neuronal apoptosis after exposure was significantly higher than in the control rats at 24 h and 48 h, and the apoptotic cells decreased one week after exposure. IHC and WB showed HSP70 expression was significantly higher in the exposed rats, peaked at 24 h.</p><p><b>CONCLUSION</b>Exposure to 140 dB (8 Hz) infrasound for 2 h per day for 3 days appeared to induce damage to the hippocampus of rats, based on changes in ultrastructure and increased cell apoptosis. However, recovery from the damage occurred overtime. HSP70 expression also increased after the exposure and decreased by 48.</p>
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Animals , Male , Rats , Apoptosis , Blotting, Western , HSP70 Heat-Shock Proteins , Genetics , Metabolism , Hippocampus , Radiation Effects , Immunohistochemistry , In Situ Nick-End Labeling , Rats, Sprague-Dawley , SoundABSTRACT
Objective To observe the expression of the polysialic acid neural cell adhesion molecule ( PSA-NCAM) in the hippocampus of rats after exposure to low intensity ( 16 Hz,90 dB) infrasound for different periods.Methods One hundred and twenty male Sprague-Dawley rats were randomly divided into infrasound exposure and normal groups.The exposure group was tjem further divided into 1 day,7 days,14 days and 21 days exposure groups.After exposure,the rats' brains were removed and an immunohistochemical technique was used to observe the expression of PSA-NCAM in the hippocampus after 1,7,14 or 21 days of exposure. Methods The expression of PSA-NCAM had increased significantly after exposure for 7 days. It peaked at 14 days,then had decreased by 21 days,but always remaining higher than in the normal group.After the infrasound exposure had ended,the expression of PSA-NCAM demonstrated a tendency of decrease over time,and the least was on the 21st day.The largest decrease was observed in the 14 days exposure groups. Conclusion 16 Hz,90 dB infrasound can increase the expression of PSA-NCAM in the hippocampus,at least in rats.This suggests that low intensity infrasound might initiate recovery of an injured central nervous system.Migration of neural stem cells may aid in the repair of neural injuries resulted from infrasound exposure.
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Objective To investigate the effect of infrasound on the growth of bone marrow mescenchymal stem cells (BMSCs) and seek the most reasonable duration for using infrasound. Methods The primary BMSCs were obtained from Sprague-Dawley rats through whole bone marrow adherent cultivation.The cells of passage 3 were divided into trial groups treated with infrasound for 10 min,30 min or 60 min,and control groups which were not treated with infrasound but exposed to air for the same durations.The vitality of cell proliferation was measured using the CCK8 method.Apoptosis and the cell cycle were analysed with flow cytometry (FACS). Results After cultivation for 72 h,the optical density (OD) values for BMSCs treated with infrasound for 10 min,30 min and 60 min were 1.480 ± 0.030,1.348 ± 0.030,1.493 ± 0.030 respectively and after 96 h they were 1.774 ± 0.030,1.731 ± 0.030 and 1.833 ± 0.030.All of which were significantly greater than in the control groups ( 1.479 ± 0.030,1.267 ±0.030 and 1.227 ± 0.030 after 72 h and 1.567 ± 0.030,1.563 ± 0.030 and 1.632 ± 0.030 after 96 h).With the extension of the treatment duration,the OD values of the BMSCs increased or increased after decreasing,and the OD value for BMSCs treated with infrasound for 60 min was the highest.The FACS results indicated no effect of infrasound on apoptosis of BMSCs when the treatment duration was 30 min,but that cell apoptosis could be inhibited when the treatment duration was 10 min or 60 min.The early phase apoptosis rates were 1.07％ ± 0.12％ and 0.97％ ±0.21％ in the trial groups treated for 10 min and 60 min respectively,and 1.43％ ± 0.06％ and 3.33％ ± 0.15％ in the respective control groups,a highly significant difference.The results of cell cycle analysis showed infrasound could disturb the cell division of BMSCs significantly when the treatment duration was less than 30 min,but there was no significant effect when the treatment duration was 60 min. Conclusions Infrasound can promote cell proliferation and disturb cell division,but it did not cause apoptosis of BMSCs.When the treatment duration was 60 min,cell proliferation improved steadily,the apoptosis rate decreased,and the cell cycle did not change.So 60 min is the most reasonable treatment duration for infrasound.
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Objective To investigate the effects of infrasound at different frequencies on the pathological morphology of mouse testes and to explore the possible involvement of β-cateinin in the mechanism of injury. MethodsSixty adult BALB/C mice were randomly divided into 2 groups.One group of 6 mice were the controls without infrasound exposure.The other group with 54 mice was evenly divided into 3 subgroups of 18 exposed to 130 dB infrasound at 4 Hz,8 Hz or 20 Hz for 2 hours daily.The pathological morphology of the mice's testes was observed 3,9 and 21 h after exposure.Immunohistochemical staining was used to examine β-catenin expression 3 h after exposure.ResultsMarked damage was observed in the morphology of the testicular cells of rats in the 8 Hz group.Cell denaturation was found in germinal cells.The cell structure was loosened and the cell junctions had decreased or disappeared.The damage was most serious at 3 h after exposure.But at the same time point,pathological damage of testicular cells was not obvious in the 4 Hz group,with only a few testes cells swollen.The morphology of testicular tissue of mice in the 20 Hz subgroup exhibited no significant difference from the control group.β-catenin was mainly found in the membranes of Leydig cells,Sertoli cells and myoepithelial cells in all of the mice,and there was no significant change in the expression level or distribution pattern between the exposed mice and the controls.No expression ofβ-catenin was found in spermatogenic cells. ConclusionInfrasound at 4 Hz or 8 Hz can damage testicular tissue,at least in mice.At 20 Hz there is no significant effect on the testes.The loosened cell structure might have been caused by the mechanical force produced by the infrasound and not by any decrease of β-catenin.
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Objective To observe the effect of low level infrasound on neuropathic pain and explore its underlying mechanism. Methods Rats were divided into experimental and control groups after their L5 spinal nerves had been ligated to create a neuropathic pain model. The experimental group was subjected to 40 to 80 dB infra sound. The control group received no infrasound treatment. Paw withdrawal latency in response to heat radiation was measured and the average gray scale of the microglia in a slice of the L5 spinal cord was compared. Results The experimental group expressed significantly lengthened paw withdrawal latency on the 12th and 14th day. The average gray scale showed significantly weakened activation of spinal microglia in the 2nd week of infrasound treatment compared with the control group. Conclusion Low level infrasound can ameliorate neuropathic pain to a certain extent,which might be related with inhibition of spinal microglia.
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Objective To investigate renal tissue changes in rats exposed to 16 Hz/130 dB infrasound.Methods Twenty male Sprague-Dawley adult rats were randomly divided into a control group,a pseudo-infrasound group,and two infrasound groups-A and B.Groups A and B were exposed to 16 Hz/130 dB infrasound for 2 h or4 h daily respectively over 7 days.Pathological and uhrastruetural changes in their renal tissues were observed with a light microscope and an electron microscope.Results Under the light microscope,Bowman's capsules expanded,epithelial cells were shed,and a little secretion was found in the renal tubules of infrasound group A.Slight degeneration and necrosis of the renal tubules and glomerular exudation could be observed in group B.Under the electron microscope,a large number of lysosomes displayed hyperplasia,there was interstitial edema,and leukocyte pavementing wag found in group B.Other changes such as swelling of podocytes' processes,fusion of foot processes,and vacuolization in the mitochondria could be observed in both infrasound groups.Conclusion Lengthy exposure to 16 Hz/130 dB infrasound can cause severe pathological and uhrastruetural changes in renal tissue,at least in rats.
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Objective To study the effect of integrin β1 antisense oligodeoxynucleotide(ASODN)on the expression of F-actin in ECV-304 ceils exposed to infrasound,and to explore the pathway of infrasound signal transfer into the cells.Methods integrin β1 oligodeoxynucleotides were embedded in cationic liposome lipofectamine 2000 reagent and transfected into ECV-304 cells.Laser scanning confoeal microscopv was used to observe F-actin's expression when the cells were exposed to 16 Hz infrasound at 130 dB for 2 h.The cells' average fluorescence was examined using spectrofluorimetric quantification after immunofluorescent staining. Results Among the three false exposure groups,most fluorescein-labelled substances in the cells were in a diffuse state.There were few actin filaments,and they were tenuous and short, without direction.The cells' fluorescence intensities were almost the same.In a group exposed to infrasound,F-actin was thick and long with a longitudinal arrangement.Fluorescence intensities were strong.However,less F-actin expression was observed in the ceils of the ASODN group exposed to infrasound compared with the others similarly exposed.Correspondingly.F-actin expression in the ASODN group exposed to infrasound was almost the same as in the other exposed group.Conclusion F-actin expression can be increased in ECV-304 cells by infrasound exposure,but integrin β1 ASODN may partially inhibit its expression.The extraeellular matrix-integrin-cytoskeleton may be one of the transduetion pathways for infrasound signals into the cells.
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Objective To investigate the influence of infasound therapy on Raji cells. Methods The Raji cell line was cultivated routinely and grouped as an infrasound and a control groups.Infrasound 8TM was used as a therapeutic infrasound generator which worked in 3 modes(frequency range 4～20 Hz,infrasound energy less than 90 dB).The applicator of the infasound generator was put on 1.5～2.0 cm fom the surface of liquid in the dish containing Raji ceil.Raji cells would be treated for 15,30,60,and 90 minutes,then tested with trypan blue assay,MTT assay,flow cytometry anatysis,and scanning electron microscope(SEM)after 0,24,and 48 h cultivations,respectively. Results Trypan blue assay showed that there were no significant differences between the 2 groups(P>0.05).MTT assay showed that although optical density value of the infrasound groups seemed to be lower than that of the control group.the differences were not significant(P>0.05).Flow cytometry analysis showed that the rate of necrotic cells and apoptosis cells in all groups was less than 10%;and that the differences between all groups were not significant(P>0.05).The scanning electron microscopy showed that the cells treated by infasound exposure for 120 minutes and then cuhivated for 24 h showed that the prominent or micro-floss of the membrane become shorten and decreased.The surface of the membrane became smooth. Conclusion Infrasound(less than 90 dB)treatment in the experiment had no obvious influence on multiplication and apoptosis of Raji cells.But the membrane of Raji cell Would be affected directly by the infrasound,and the penetration of the membrane could be changed.
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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.
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Objective To study the effects and mechanisms of infrasound with low sound pressure level on focal cerebral ischemia-refusion injury. Methods Focal cerebral ischemia was produced by 2 hours of occlusion of the middle cerebral artery in rats. lnfrasound generated by infrasound 8TM device was used as treatment factor. Thirty-two Sprague-Dawley rats were divided into three groups: sham group (n=8), model group (n=8) and in-frasound group (n=16) , and the infrasound group was subdivided into 20- and 120-min infrasound groups, with 8 rats in each group. Neurological symptoms was assessed at 2 h, 1 d, 3 d and 7 d, respectively. These rats were sacrificed after 7 days of infrasound treatment and their brains were harvested. The number of IGF-1 posive cells of ischemia cortex was counted by using immunohistochemical technique. Results Compared with model group, neurological symptoms of rats in 120-min infrasound group was significantly improved (P<0.05); the number of IGF-1 positive cells of ischemia cortex in 120-min infrasound group increased significantly as compared with that in model group (P<0.01). Conclusion Infrasound with low sound pressure level (120 min/d, 7 d) could exert neuroprotective effect in focal cerebral ischemia injury by increasing expression of IGF-1 in brain.
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@#Objective To study the effect of 16 Hz infrasound on the proliferation of the neural stem cells in rats' hippocampus.Methods72 SD rats were randomized into 16 Hz-130 dB infrasound exposure group(n=24),16 Hz-90 dB infrasound exposure group(n=24)and control group(n=24).Rats of the infrasound exposure groups were exposed to 16Hz 90dB/130dB infrasound barochamber system,2 h/d for 1 d,7 d,14 d,or 21 d.Their brains were removed and anti-nestin immunohistochemistry was used to observe the neural stem cells in rats' hippocampus.ResultsThe expression of nestin in rats' hippocampus increased after exposure for once and increased with the exposure time.It reached its peak on the 14th day,decreased on the 21st day but remained higher level.The reaction of 90 dB group was weaker than that of 130 dB group.ConclusionThe brain injuries result from 16 Hz infrasound exposure can enhance the proliferation of neural stem cells in rats' hippocampus which might participate in the repair of neural injuries.
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@#ObjectiveTo study the effects of Jiawei Buyang Huanwu Decoction on learning and memory abilities of mice exposed to 130 dB infrasound (16 Hz). Methods80 BALB/c mice were divided into blank-control group, infrasound-control group, infrasound and drug-treated group (it was divided into 3 sub-groups according to dose). Learning and memory abilities were measured 14 d later. ResultsCompared with blank-control group, learning and memory abilities decreased (P<0.05) in infrasound-control group. Compared with infrasound-control group, learning and memory abilities increased(P<0.01) in infrasound and drug-treated group. Conclusion16 Hz,130 dB infrasound could damage learning and memory abilities. Jiawei Buyang Huanwu Decoction could protect mice from learning and memory harm exposed to the infrasound.
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Objective To study the effects of Jia Wei Bu Yang Huan Wu decoction on learning and memory abilities, superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) activities and the contents of malondialdehyde (MDA) in mice exposed to 16 Hz,130 dB infrasound. Methods Fifty BALB/c mice were divided into a control group (group C), an infrasound-control group (IC group), an infrasound and drug-treated group (ID group). Learning and memory abilities,SOD and GSH-PX activities and MDA contents were measured 14 d after corresponding treatment. Results Compared with those in group C, learning and memory abilities was significantly decreased(P0.05)in IC group. Compared with those in IC group, learning and memory abilities was increased(P
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@#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 8Hz,90dB,100dB and 130dB 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.
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Objective To study the effect of 8Hz infrasound on the expression of 5-HTR of hippocampus and temporal cortex in rats. Methods SD rats were exposed to 8Hz, 90dB,100dB or 130dB infrasound, respectively for 2 hours daily. Then the rats' brains were taken and given stained immunohistochemically for (5-hydroxy tryptamine receptor,5-HTR). The content of 5-HTR in hippocampus and temporal cortex were detected under an optical microscope. Results The animals in the infrasound groups had less expression of 5-HTR in hippocampus and temporal cortex, and the least were at the 35th day for 90dB group and 100dB group and the 28th day for 130dB group (P
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0.05),but there are increases of that in 90dB/7d ( P 0.05). Conclusion The results showed that 8Hz, 90dB/130dB infrasound definitely induced increases of apoptosis ratio in the hippocampus cells after certain time of exposure, suggesting that there are damages occurred by infrasound field with 90dB or 130dB and some adaptation of the hippocampal cells ensued after a certain period of time.
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Objective To further investigate the threshold value and the dose-effect relationship of infrasound on the rat pallium, and to observe the effects on the pallium's ultrastructure. Methods Rats were exposed to 16 Hz, 90 dB infrasound for 2 hours daily. With a transmission electron microscope, changes in the ultrastructure of the cortex of the rats' parietal lobes were observed 2 hours, 3 days and 7 days after the treatment. Results There were no changes in the ultrastructure of the pallium in rats which had been exposed for 7 days or 14 days. Denaturation appeared when the rats had been exposed for 21 days, 28 days or 35 days. Denaturation become more serious as the exposure time increased beyond 21 days. Denaturation and damage gradually returned to normal with time after exposure. Conclusion 16 Hz, 90 dB infrasound exposure over an extended time may cause denaturation and other changes in the ultrastructure of the pallium in rats. Such changes can return to normal with time.