次声对大鼠前脑部分作用效应的实验研究

发布时间：2018-01-01 09:04

本文关键词：次声对大鼠前脑部分作用效应的实验研究　出处：《第四军医大学》2007年硕士论文　论文类型：学位论文

【摘要】： 次声是由物体机械振动产生的频率为0.0001～20 Hz的声波,其概念最早由法国科学家Gavreau于1966年提出。次声广泛存在于自然界和社会环境中,其频率低,波长大,传播过程中不易被吸收,衰减甚小,传播远,穿透力强,对生物体的作用效应巨大。高强度次声对人体有害,是生产噪声和公共噪声的重要组成部分。长时间次声作用可导致工作人员出现乏力、淡漠、抑郁、耳受压感、注意力降低、困倦、内脏震动感,并可伴有颅腔静脉血流减少。次声对生物体的基本作用原理是生物共振。其产生的效应广泛而复杂,涉及系统、器官、组织、细胞以至分子水平。以往研究表明,次声引起的各脏器结构与功能损伤中,最为首要的是脑的损害。脑内多种神经递质的代谢、组织细胞的结构和功能在次声作用下都受到影响。一定频率和声强的次声作用一段时间,可以造成脑内皮质、海马、下丘脑、边缘系统等多个部位的损害,其机制复杂。生物体必须感受环境变化,并做出反应。近年研究发现,瞬时感受电位蛋白(transient receptor potential, TRP)家族在哺乳动物体内扮演着细胞感受器的角色,将细胞外环境的变化翻译为膜兴奋性和第二信使信号(如Ca2+)的变化。它们是感觉系统的主力军,可对温度、触摸、渗透压、信息素、味道等多种刺激产生反应;不仅参与经典的感觉转导,还是古老的细胞感觉器官,能够感受胞内外的各种刺激。其中TRPV4是一种渗透压/机械感受器。近年发现星形胶质细胞积极参与脑生理活动,它与神经元之间相互影响,存在着广泛的信息交流。大量证据表明,突触兴奋后突触前终末释放神经递质使邻近胶质细胞内Ca2+浓度升高,释放不同的递质,反馈作用于神经突触,影响突触后神经元的兴奋性,又能够调节突触前终末的神经递质释放。因此我们推测次声作用引起的脑损伤可能与次声作用过程中星形胶质细胞和神经元间的相互作用相关。胶质原纤维酸性蛋白(GFAP)是星形胶质中间丝的构成蛋白,是星形胶质细胞的特异性标记物,在胶质细胞功能活跃时表达增加,常被作为星形胶质细胞活动状态的标志之一。c-fos作为一种即刻早期基因广泛作用于反应神经元的功能状态。次声作为一种机械振动波通过共振效应引起动物和人体的反应,该过程是如何由机体感知并做出反应的,目前研究较少。为研究次声对前脑作用的效应过程,本实验依靠次声压力仓系统,建立16Hz,90dB及130dB次声脑损伤大鼠模型,采用免疫组织化学方法观察海马、皮质、下丘脑、杏仁核等部位的瞬时感受电位香草酸家族4(transient receptor potential vanilloid 4,TRPV4)通道蛋白、胶质原纤维酸性蛋白(Glial Fibrillar Acidic Protein,GFAP)以及Fos蛋白表达的情况,探讨次声作用过程中,脑细胞是如何感受次声刺激的,在该过程中,星形胶质细胞与神经元的反应与相互作用情况如何。在实验中我们观察到,在海马、皮质、下丘脑、杏仁核等部位: 1、TRPV4表达:对照组基本无阳性染色。16HZ,130dB组可见胞浆染色的TRPV4阳性神经元较对照组显著增多,在海马、皮质、下丘脑室旁核和杏仁核都增多。胞体较小,胞核不明显,二氨基联苯胺(DAB)显色时阳性物质呈深蓝色。16Hz,90dB组在相同部位也出现TRPV4阳性细胞。每个部位各组间差异有统计学意义(P0.05)。 2、GFAP表达:对照组大鼠上述部位GFAP阳性细胞胞体小,突起细而互相平行,分支少,染色浅。16HZ,130dB组可见GFAP阳性星形胶质细胞胞体较对照组明显增大,突起增粗,数量增加,密度增加,灰度加深;16HZ,90dB组GFAP阳性细胞也较对照组增多,但较130dB组为少;每个部位各组间差异有统计学意义(P 0.05)。 3、Fos表达:对照组大鼠上述部位Fos阳性神经元很少。16HZ,130dB组可见胞核染色的Fos阳性神经元较对照组显著增多;16HZ,90dB组Fos阳性神经元也较对照组增多,但较130dB组为少;每个部位各组间差异有统计学意义(P 0.05)。研究结果提示: 16HZ,90dB和130dB次声作用可以引起大鼠海马、皮质、下丘脑室旁核及杏仁核TRPV4阳性细胞表达较对照组增多,提示脑细胞可能是通过TRPV4蛋白感受次声这种机械刺激;同时上述部位实验组GFAP阳性星形胶质细胞和fos阳性神经元的表达也较对照组增多,分布一致,关系密切。上述部位神经元和星形胶质细胞的激活可能分别与次声引起的学习记忆功能损害、应激反应相关。
[Abstract]:Infrasound is caused by body mechanical vibration frequency is 0.0001 ~ 20 Hz wave, the concept was first proposed by French scientist Gavreau in 1966. Infrasound exists widely in the nature and social environment, the low frequency waves grow up, can't be absorbed in the process of communication, the attenuation is very small, far transmission, strong penetration the role, effects to the organism is huge. High intensity infrasound is harmful to the human body, is an important part of production and public noise. Long time exposure to infrasound can cause staff fatigue, apathy, depression, ear compression feeling, attention decreased, drowsiness visceral vibration feeling, and can reduce with cranial venous flow.
The basic principle of infrasound effect on the organism's biological resonance whose effects are extensive and complex, involving the system, organ, tissue, cell and molecule. Previous studies showed that the structure and function of organ damage caused by infrasound, the most important is brain damage. Neurotransmitters in brain metabolism, structure and the function of tissues and cells are affected by infrasound. Infrasound of certain frequency and intensity for a period of time, can cause brain cortex, hippocampus, hypothalamus, limbic system and other parts of the damage, the mechanism is complicated.
The organism must feel the changes of environment, and respond. Recent studies have found that transient receptor potential protein (transient receptor potential, TRP) family plays a role in cell receptors in mammals, the changes of extracellular environment for membrane excitability and second messenger signals (such as Ca2+) change. They are the main force of feeling system, to touch, temperature, osmotic pressure, pheromone, taste and other stimuli; sensory transduction is not only involved in the classic, or old cells of sensory organs, can feel the extracellular stimuli. TRPV4 is a kind of osmotic pressure / mechanoreceptors. In recent years found that astrocytes actively participate in brain physiological activity, interaction between it and neurons, the existence of information communication. Evidence suggests that synaptic excitatory neurotransmitter release after presynaptic terminals of adjacent glial cells The Ca2+ concentration increased, the release of different neurotransmitters, the feedback effect on nerve synapses, affect the excitability of postsynaptic neurons, neurotransmitters and can regulate presynaptic terminal release. So we speculate that the related brain injury may be associated with infrasound induced by infrasound of star shaped glial cells and neurons in the interaction.
Glial fibrillary acidic protein (GFAP) is a glial intermediate filament protein composition, is a specific marker of astrocytes, increased expression of glial cells in the active function, function is often as a sign of astrocyte activity state of.C-fos as an immediate early gene is widely expressed in neurons in response.
Infrasound as a mechanical vibration wave through the resonance effect caused by human and animal reaction, the process of how the body sense and respond, there has been little research. To investigate the effect of infrasound on the role of forebrain process, the experiment on infrasonic pressure chamber system, the establishment of 16Hz, 90dB and 130dB in rat model of infrasonic brain injury. Study of the hippocampus, immunohistochemistry cortex, hypothalamus, amygdala and other parts of the transient receptor potential vanilloid family 4 (transient receptor potential vanilloid 4, TRPV4) channel protein, glial fibrillary acidic protein (Glial Fibrillar Acidic Protein, GFAP) and the expression of Fos protein, to explore the effects of infrasound in the process of brain cells how is the feeling of infrasound, in this process, how to astrocytes and neuron responses and interaction.
In the experiment, we observed that in the hippocampus, the cortex, the hypothalamus, the amygdala, and other parts:
1, the expression of TRPV4: the control group have no positive staining of.16HZ, TRPV4, 130dB group showed cytoplasmic staining positive neurons increased significantly, compared with the control group in the hippocampus, cortex, hypothalamic paraventricular nucleus and amygdala are increased. Smaller cell body, the nucleus is not obvious, two amino benzidine (DAB) color positive material a dark blue.16Hz, 90dB group, TRPV4 positive cells appeared in the same location. There were statistically significant differences between groups for each site (P0.05).
2, the expression of GFAP: the rats in the control group the parts of the bodies of GFAP positive cells is small, thin and protruding parallel to each other, fewer branches, pale staining.16HZ, 130dB group showed GFAP positive astrocytes cells compared with the control group significantly increased, the increase in the number of neurites thickening, increased density, gray 16HZ, 90dB group to deepen; GFAP positive cells increased significantly than the control group, but less than the 130dB group; there were statistically significant differences between groups for each site (P 0.05).
3, the expression of Fos positive neurons in the control part of the rats in group Fos little.16HZ, 130dB group showed cell nuclear staining of Fos positive neurons increased significantly than the control group; 16HZ 90dB group, Fos positive neurons also increased significantly than the control group, but less than the 130dB group; there were statistically significant differences between groups (0.05 in each part of P).
The results of this study suggest that 16HZ, 90dB and 130dB infrasound can induce rat hippocampus, cortex, hypothalamic paraventricular nucleus of the amygdala and the expression of TRPV4 positive cells increased significantly than the control group, suggesting that brain cells may feel this infrasound mechanical stimulation by TRPV4 protein; while the expression of glial cells and Fos positive neurons in the experimental group of GFAP positive astrocytes of the site it was more than that in control group, the same distribution, are closely related. The positions of neurons and astrocytes activation and impairment of learning and memory may be caused by infrasound, stress.

【学位授予单位】：第四军医大学
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R363

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