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Sun JR  Ye YM 《生理学报》2001,53(1):61-65
本工作观察了在超重(2G)环境中出生、生态4个月后返回正常(1G)环境的Long-Evans大鼠运动行为的改变和恢复,以及相关脑区Fos表达水平的变化,并与旋转刺激(重力变化的对照组)和去前庭传入大鼠相比较,结果表明:重力的变化导致实验大鼠表态和运行行为模式改变,伸肌张力增加,运动平衡、游泳定向和空中翻正的能力降低,对1G环境再适应的时程因行为的不同而异,其中游泳定向能力的恢复时间最长,长于1个月,旋转只对运动行为有短暂的影响。Fos表达被认为是揭示参与应答感觉刺激而功能活跃脑区的有用工具。结果显示,正常和毁迷路的对照大鼠的Fos呈低水平表达,减重刺激使上、下丘脑和围导水管灰质、中缝背核及孤束核的水平显著上调,相反,下橄榄、蓝斑和前庭核团的Fos水平没有明显改变,表明脑干对不同重力刺激存在不同的调控神经途径。  相似文献   

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次声对前庭和耳蜗的影响   总被引:2,自引:0,他引:2       下载免费PDF全文
本研究发现:(1)140dB SPL次声暴露引起耳蜗功能和形态的永久性损伤.(2)120dB SPL次声暴露对耳蜗功能和形态仪是暂时性损伤.(3)120dB SPL和140dB SPL次声暴露都能引起前庭功能和形态的变化.(4)低声强(120dB SPL)次声暴露仅受累前庭,高声强(140dB SPL)次声暴露,前庭和耳蜗皆受累.(5)次声对前庭损伤要比耳蜗明显.  相似文献   

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前庭功能的中枢组胺能神经调制   总被引:1,自引:0,他引:1  
Bergquist F  Dutia MB 《生理学报》2006,58(4):293-304
组胺能药物已经长期用于治疗人类的平衡紊乱,但对于它们在前庭系统中作用的机制还缺乏了解。在本文中,我们综述了关于脑内(特别是脑干前庭核中)的组胺能神经传递,以及组胺在脑可塑性——“前庭代偿”(一种单侧外周前庭损伤之后发生的行为学恢复)中作用的新近文献。我们在综述组胺能类药物促进前庭代偿证据的同时,也讨论了这类药物临床应用的可能性。  相似文献   

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目的:随着强静磁场的广泛应用,其生物安全性评估获得越来越多的关注。本文通过实验,评估强静磁场照射对小鼠前庭系统、学习记忆能力的影响及两者内在联系。方法:观察12T强静磁场照射2h条件下小鼠即时(2min内)效应和条件味觉厌恶反应情况,确定照射对小鼠前庭系统的影响;通过Y迷宫和Morris水迷宫实验,分析照射对小鼠学习记忆能力的影响。结果:研究发现照射后小鼠立即出现直立行为抑制、旋转平衡失调,以及持续10d的条件味觉厌恶反应,表明该照射对小鼠前庭系统造成了即时及持续影响。Y迷宫和Morris水迷宫分析结果表明照射后小鼠学习记忆能力未发生显著改变。结论:12T强静磁场2h照射对小鼠前庭系统存在显著影响和量效关系,照射可导致小鼠出现平衡失调,持续味觉厌恶的现象,但这种影响并非结构性或不可逆的,对小鼠学习记忆能力未造成影响。  相似文献   

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目的:分析我国民航飞行驾驶员和乘务员视眼动功能试验和前庭眼动反射试验检查结果的特征,并探讨视眼动功能试验和前庭眼动反射试验检查运用于民航飞行人员日常体检的可能性.方法:应用美国EDI公司的红外视频眼震电图仪,对我国40名民航飞行驾驶员和40名乘务员,进行视眼动功能试验(包括平稳跟踪试验、视动试验和扫视跟踪试验)和前庭眼动反射试验检查,并对检查结果进行比较分析.结果:前庭眼动反射试验结果与视眼动功能试验结果一致性较好,且与视眼动功能试验相比前庭眼动反射试验具有更高的敏感性.结论:前庭眼动反射试验检查技术有高频、宽频和操作方法简便等优点,适合应用到民航飞行人员的年度体检中,对民航飞行人员的前庭功能状态进行初步评定.  相似文献   

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目的:探讨学龄前儿童超重和肥胖的现状及其影响因素。方法:从青岛市幼儿园招募年龄在3-6 岁儿童参与本调查,通过健康体格检查和问卷调查两部分进行。其中体格检查包括身高和体重的测量,问卷调查内容包括父母的相关变量以及儿童个人饮食行为等因素。其中1080 份为完整有效数据。结果:学龄前儿童超重和肥胖人数分别占总数的18.80%和8.98%。男孩的超重和肥胖率(31.8%)高于女生(23.8%)。父亲和母亲的超重和肥胖均与儿童超重和肥胖存在关联性(P<0.05)。较长屏幕时间、快速进食是超重和肥胖的危险因素(P<0.05),而增加体力活动时间为保护因素(P<0.05)。偏爱肉类也是与超重/ 肥胖相关的因素(P<0.05)。结论:孩子个性习惯和父母均与学龄前儿童超重和肥胖相关,学龄前儿童超重和肥胖问题仍然是一个重要的公共卫生问题。  相似文献   

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目的:研究运动干预对不同糖耐量超重肥胖孕妇孕期体重增加、妊娠晚期血清游离脂肪酸(Free Fatty Acids,FFA)、甘油三酯(Triglyceride,TG)水平及新生儿体重的影响.方法:2008年6月~2009年12月,对来自高危门诊的的肥胖超重孕妇,分别给予单纯饮食干预(饮食组)或运动饮食联合干预(运动加饮食组).妊娠32周采集两组病例空腹血样,测定FFA及TG.排除各组有运动禁忌的孕妇.足月分娩妊娠期糖尿病(Gestational Diabetes Mellitus,GDM)及正常糖耐量(Normal Glucose Tolerant,NGT)孕妇共143例,运动加饮食组(n=73,GDM 21例,NGT 52例).饮食组(n=70,GDM23例,NGT47例)按不同糖耐量分别进行了对比研究.分析二组在孕期体重增加,孕晚期脂代谢水平及新生儿出生体重方面的差异,并就新生儿出生体重与孕期体重增加及孕晚期血清FFA水平的关系做相关性分析.结果:两组孕妇在年龄,孕前体重指数及分娩孕周方面差别无统计学意义.两组GDM在孕期增重(p<0.01)、新生几出生体重体重(p<0.05)、孕晚期血清FFA(p<0.05)、TG水平(p<0.05)等方面差别有显著性.两组NGT在孕期体重增加(p<0.05)及新生儿出生体重方面差别有显著性(p<0.05);饮食组平均血清FFA及TG水平高于运动加饮食组,但未形成显著性差异.饮食组新生儿出生体重与孕期增重(NGT,r=0.468,P<0.01;GDM,r=0.564,p<0.01)及孕32周血清FFA水平(NGT,r=0.431,P<0.05;GDM,r=0.462,p<0.05)相关有显著性.饮食加运动组新生儿出生体重与孕期增重相关无显著性,与血清FFA相关有显著性(NGT,r=0.375,P<0.05;GDM,r=0.405,p<0.05).两组孕妇在巨大儿发生率方面有显著性差异.结论:肥胖超重孕妇新生儿出生体重与孕晚期血清FFA水平有关.饮食结合运动干预有助于肥胖超重GDM孕妇在孕期体重增加,妊娠晚期血清FFA水平,新生儿出生体重,巨大儿发生率等方面取得良好的妊娠结局.  相似文献   

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目的 了解北京市西城区中学生体力活动的情况,探讨中学生超重肥胖相关行为现状及影响因素,为制定干预措施提供科学依据.方法 采取整群随机抽样方法,对北京市西城区9所中学59个班级1 930名在校生使用“北京市青少年健康相关行为调查问卷”进行调查.结果 在过去7d中,有74.8%和59.1%中学生分别参加体育锻炼和中等强度运动;平均每天看电视、玩电子游戏、上网超过2h的报告率分别为24.9%,11.9%和31.9%.参加体育锻炼、中等强度运动、玩电子游戏行为报告率男生高于女生.职高学生、自感学习成绩差的中学生运动行为报告率较低,静态行为报告率较高.母亲文化程度越高,家庭类型为核心或大家庭中学生运动行为报告率越高,静态行为报告率越低.男生患超重肥胖的危险是女生的3.207倍;平均每天看电视超过4h的中学生患超重肥胖的危险是平均每天看电视不足1h中学生的1.755倍.结论 广泛开展健康教育,增强中学生健康理念,引导科学运动,控制看电视、上网和玩电子游戏的时间,可以减少青少年超重和肥胖的发生.  相似文献   

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本文观测了Acetyl-DL-leucine(AL、一种抗眩晕药)对猫单侧前庭神经切断后前庭代偿的影响。结果显示:AL加快术后猫在转动横梁测试中运动平衡能力的恢复,但抑制去传入前庭外侧核神经元(n=506)静息自发放电频率的恢复。AL促进放电活动与头部左右摆动体位相关的神经元数量和比例的恢复,从术后的第1周的10%(n=454),逐渐提高到术后第3周的60%,第5周的75%  相似文献   

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1. When the Ringer''s solution applied to isolated frog sciatic nerve contains K+ in concentrations greater than 2 x standard, the height of the spike and of the after-potential is decreased, as is the duration of the after-potential; recovery of height and of excitability following response is delayed; degree and duration of supernormal excitability are decreased; postcathodal depression and postanodal enhancement are increased and prolonged. 2. The nerve functions just listed in general all change in the opposite direction when exposed'' to increased environmental [Ca++]. (4.5–20 x standard) or decreased [K+] (0.05–0.2 x standard). The effects of decreased [Ca++] (0.20–0.25 x standard) are indeterminate. 3. When [K+] and [Ca++] are both greater than 2 x standard, whatever the ratio between the concentrations the effects characteristic of high [K+] eventually predominate. However, these effects, except for those involving spike height, are preceded by effects characteristic of high [Ca++] when this cation is present in sufficient excess. 4. When [K+] and [Ca++] are reduced to equal low levels (0.1–0.2 x standard), effects characteristic of low [K+] and high [Ca++] are obtained. 5. The experimentally determined order of ability of the environments to produce changes characteristic of high K+ (which is the reverse of the order of their ability to produce changes characteristic of high [Ca++]), is not the order of their K+ or Ca++ concentrations, nor of the ratio between these concentrations (Table II). 6. The results may be explained by the assumption that the functions investigated are all to greater or less degree controlled by (1) the [K+]/[Ca++] ratio and (2) the K+ concentration, at least when this exceeds a critical level. Control by [K+] is more effective for spike height and its recovery after stimulation than for the other functions. The special rôle of K+ is attributed to an unknown specific effect of this ion which Ca++ is unable to oppose. It is suggested that this K+ effect in general becomes marked on the frog nerve functions investigated when the K+ concentration is somewhat above 2 x standard, while the [K+]/[Ca++] ratio must be changed by a factor of 4 or more before it exerts a definite effect on these functions. 7. In standard and in modified cationic environments, nerve functions vary in the ease with which they manifest changes characteristic of high [K+] or of high [Ca++]. 8. The after-potential functions are less completely controlled by the cationic environment than are the other functions investigated.  相似文献   

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沙棘油对实验性血栓形成及凝血系统的影响   总被引:5,自引:0,他引:5  
沙棘油能使实验性血栓形成延迟,具有预防血栓形成的作用。沙棘油有一定的抗凝作用,主要参与内源性凝血系统;且有促纤溶作用,明显降低纤维蛋白原含量,使血浆鱼精蛋白副凝试验呈阳性反应。  相似文献   

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为获取高活力的外套膜细胞,研究通过常压室温等离子体(Atmospheric and room temperature plasma,ARTP)诱变和流式细胞术等技术分析了不同诱变气量组(10、12和15 SLM组)和处理时间对三角帆蚌(Hyriopsis cumingii)体外培养的外套膜细胞的细胞活性及生物矿化相关功...  相似文献   

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研究选取了水体常见蓝藻优势种类——铜绿微囊藻(Microcystis aeruginosa PCC7806)作为研究对象, 了解磺酰脲类除草剂甲磺隆(Metsulfuron-methyl)对铜绿微囊藻生长和光合系统的影响。研究表明, 当甲磺隆浓度大于80 mg/L时, 对铜绿微囊藻的生长具有显著抑制。通过回归分析和Probit分析, 甲磺隆对铜绿微囊藻生长的EC50为81.998 mg/L。细胞色素研究结果显示, 实验第6天, 各浓度处理下单位细胞内Chl.a和类胡萝卜素含量均低于对照组, 且当甲磺隆浓度为80 mg/L时, 单位细胞内类胡萝卜素含量显著低于对照组。快速叶绿素荧光诱导动力学变化结果分析显示, 实验第6天甲磺隆胁迫下单位反应中心捕获的用于电子传递的能量(ET0/RC)及单位反应中心用于电子传递的量子产额(φE0)受到显著抑制, 综合细胞色素变化结果显示, 甲磺隆能显著抑制光合系统反应中心电子受体侧电子性能。综上所述, 甲磺隆可能作用于光合系统反应中心电子受体侧, 从而对铜绿微囊藻光合系统造成影响。  相似文献   

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Expressions for male and female fitnesses of partially self-fertilizing cosexual plants are derived, assuming that allocation to pollinator attraction at the time of flowering may decrease resources available for male and female primary structures. The total female fertility is assumed to be controlled by factors at two stages, flowering-time and fruiting-time, with resources for fruit maturation being limited so that maximum seed production may be limited by the availability of these resources. The fitness formulas are used to calculate ESS (evolutionarily stable strategy) allocations at flowering time to primary male and female sex functions and to attractive structures. These are compared with some data that are available for dry weights of different flower parts. The fitnesses of unisexual mutant forms are calculated, assuming that they are introduced into a population consisting mostly of the initial cosexual form and that they obey the same gain curves as that form. When compared with the fitness of the ESS cosexual form, this enables one to ask whether unisexual forms will be favored. We show that the spread of females is unlikely, unless there is high inbreeding depression and a rather high selfing rate, and that in some circumstances a linear relation between number of fertilized ovules and number of seeds matured can be less favorable for the invasion of females than is a highly concave relation. With a nearly linear relation between numbers of fertilized ovules and mature seeds, invasion by females is more likely when investment in attraction is low than when it is high. These effects are discussed in relation to the distribution of dioecy. The spread of male mutants is never likely in these models.  相似文献   

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枫香脂和苏合香的心血管药理学研究   总被引:2,自引:0,他引:2  
本文比较了苏合香及枫香脂生药、精制枫香脂、枫香脂挥发油的毒性及其对心血管系统的药理作用。结果表明 ,枫香脂毒性小于苏合香。 4种样品均能提高小鼠常压下的心肌耐缺氧能力 ,其中精制枫香脂及枫香脂挥发油的作用最强 ;均可显著降低氯仿诱导的小鼠室颤发生率 ,其中精制枫香脂作用最强 ;对体外血栓干重的抑制率 ,精制枫香脂的作用强于苏合香 ;均可提高冠脉流量 ,其中精制枫香脂及枫香脂挥发油的作用强度及作用维持时间均优于苏合香 ;对离体豚鼠心功能的影响基本相似。提示以精制枫香脂取代苏合香应用于心血管疾病是可能的。  相似文献   

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ON THE DEFINITIONS AND FUNCTIONS OF DOMINANCE AND TERRITORIALITY   总被引:4,自引:0,他引:4  
1. Dominance/subordinance is a relationship between two individuals in which one defers to the other in contest situations. Each such relationship represents an adaptive compromise for each individual in which the benefits and costs of giving in or not giving in are compared. Familiar associates in groups or neighbours on nearby territories may develop relatively stable dominant-subordinate relationships based on individual recognition. Although the aggressive aspects of dominance are usually emphasized, the less conspicuous actions of the subordinate individual are actually more important in maintaining a stable relationship. 2. In evolutionary terms, dominance essentially equals priority of access to resources in short supply. Usually the subordinate, who would probably lose in combat anyway, is better off to bide its time until better able to compete at another time or another place. Both individuals save time, energy, and the risk of injury by recognizing and abiding by an established dominant-subordinate relationship. 3. Dominance can be either absolute or predictably reversible in different locations or at different times. Of the various forms of dominance behaviour, rank hierarchies and territoriality represent the two extremes of absolute and relative dominance, respectively. A dominance hierarchy is the sum total of the adaptive compromises made between individuals in an aggregation or organized group. Many animals seem to be capable of both absolute and relative dominance, and within species-specific limits the balance may shift toward one or the other. High density, or a decrease in available resources, favours a shift from relative to absolute dominance. Some species may exhibit both simultaneously. Social mammals may have intra-group hierarchies and reciprocal territoriality between groups, while the males of lek species may exhibit ‘polarized territoriality’ by defending small individual territories, with the most dominant males holding the central territories where most of the mating takes place. 4. Territoriality is a form of space-related dominance. Most biologists agree that its most important function is to provide the territory holder with an assured supply of critical resources. Territoriality is selected for only when the individual's genetic fitness is increased because its increased access to resources outweighs the time, energy, and injury costs of territorial behaviour. 5. Territoriality was first defined narrowly as an area from which conspecifics are excluded by overt defence or advertisement. The definition has been variously expanded to include all more or less exclusive areas without regard to possible defence, and finally to include all areas in which the owner is dominant. I define territory as a fixed portion of an individual's or group's range in which it has priority of access to one or more critical resources over others who have priority elsewhere or at another time. This priority of access must be achieved through social interaction. 6. My definition excludes dominance over individual space and moving resources, and includes areas of exclusive use maintained by mutual avoidance. It differs from most other definitions in its explicit recognition of time as a territorial parameter and its rejection of exclusivity and overt defence as necessary components of territorial behaviour. There is an indivisible continuum of degrees of trespass onto territories, and functionally it is priority of access to resources that is important rather than exclusive occupancy. 7. There is a similarly indivisible continuum in the intensity of behaviour needed to achieve priority of access to resources. Deciding whether or not an exclusive area is defended leads to the pointless exercise of trying to decide which cues indicating the owner's presence are conspicuous enough to merit being called defence. Concentrating on overt defence emphasizes the aggressive aspects of territorial behaviour rather than the equally or more important submissive aspects such as passive avoidance.  相似文献   

20.
1. The uncoupling of oxidative phosphorylation of liver mitochondria by bilirubin does not occur in the presence of equimolar quantities of human serum albumin. With brain mitochondria, however, albumin was not protective. 2. A similar protective effect of albumin for liver, but not for brain, mitochondria was observed in studies of the effects of bilirubin on the 32Pi-ATP exchange reaction. 3. The latent ATPase of fresh brain mitochondria is activated by Mg2+ but only slightly by DNP. Bilirubin increased the Mg2+ stimulated ATPase activity in liver mitochondria but depressed this activity in brain mitochondria. These effects were uninfluenced by protein binding. 4. Isotope studies with [14C]bilirubin demonstrated that the affinity of brain mitochondria for albumin-bound bilirubin is not greater than that of liver mitochondria. 5. The greater toxicity of protein-bound bilirubin for brain mitochondria than for liver mitochondria might be related to the greater lipid content of brain mitochondria.  相似文献   

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