慢性温和应激抑郁模型大鼠5-羟色胺、色氨酸和应激激素的变化

目的：通过观察慢性温和应激对大鼠行为及5-羟色胺、色氨酸、应激激素的影响,进一步阐明应激致抑郁发生的机制。方法：利用慢性不可预计温和应激（CUMS）结合行为学指标建立大鼠抑郁动物模型;高效液相检测血浆和脑5-HT、儿荼酚胺;放免方法检测血浆皮质醇换算成皮质酮含量;氨基酸分析仪检测血清色氨酸的含量。结果：①CUMS诱导8周大鼠糖水偏爱性与对照组相比明显减低（P〈0．05）;体重和旷场实验评分下降（P〈0．05）。②CUMS诱导8周大鼠大脑和血浆5-HT含量显著下降（P〈0．05）;而血清色氨酸含量与对照组相比则明显升高（P〈0．05）。③CUMS诱导8周大鼠血浆去甲肾上腺素和肾上腺素含量与对照组相比明显升高（P〈0．05）：血浆皮质酮含量与对照组相比统计学上无显著性差异（P〉0．05）。结论：利用CUMS建立的抑郁模型大鼠存在着神经内分泌紊乱,CUMS大鼠抑郁样行为的发生可能与血浆去甲肾上腺素和肾上腺素升高对色氨酸代谢的影响有关。     

环境压力对不同动物脑组织激素水平的影响

分别给予中国树鼩、Wistar 大鼠、BALB/c 小鼠低频电刺激后, 用放射免疫法检测脑组织去甲肾上腺素(noradrenaline, NA)、多巴胺(dopamine,DA)、五羟色胺(serotonin, 5-HT)水平。结果发现, 给予中国树鼩、Wistar 大鼠、BALB/c 小鼠低频电刺激后12 h、24 h、36 h, NA、DA、5-HT 水平均比对照组显著升高(均P<0.01); 电刺激后12 h, NA、DA、5-HT 升高较快的动物依次为中国树鼩>Wistar 大鼠>BALB/c 小鼠。说明不同动物对同一刺激的应激敏感程度不同。     

运动性中枢疲劳后脊髓内主要神经递质含量的变化

目的：研究运动性中枢疲劳后脊髓内主要单胺类及氨基酸类神经递质含量的变化,探索运动性疲劳脊髓水平发生机制。方法：运用：Bedford递增负荷运动训练方案建立运动性中枢疲劳模型。将18只雄性成年Wistar大鼠随机分为对照组（C）,训练后即刻组（IT）及训练后3 h恢复组（RT）。用高效液相色谱法（HPLC）检测脊髓内单胺类和氨基酸类神经递质含量的变化。结果：大鼠脊髓内氨基酸类神经递质,在训练后即刻都出现了增高,其中谷氨酸（Glu）、γ-氨基丁酸（GABA）明显增高（P〈0.05）,甘氨酸（Gly）也出现增高但与对照组相比无显著性差异 训练后经3 h恢复后,氨基酸类神经递质含量基本恢复至对照组水平。单胺类神经递质,去甲肾上腺素（NE）,5-羟色胺（5-HT）在训练后即刻则出现降低趋势,且5-羟色胺（5-HT）含量在训练后3 h恢复组出现了明显降低（P〈0.05）。结论：运动性疲劳引起脊髓内神经递质含量的改变,可能与运动性中枢疲劳的发生过程有关。脊髓5-HT在恢复期仍明显降低,提示5-HT可能与疲劳恢复过程有较为密切的关系。     

亚磁场引起小鼠昼夜节律改变和热痛觉敏感增加

地外空间的亚磁场环境是影响宇航员健康的一种潜在风险因素．动物和人体实验表明,亚磁场显著影响个体行为和神经系统功能．但是,目前尚缺乏亚磁场对动物行为和生理等多方面影响的系统检测数据．本文构建了一个适用于动物饲养的亚磁场环境(< 500 nT),并系统检测了30天亚磁场处理对成年雄鼠(C57BL/6,4～6周龄,(20 ± 2) g)的昼夜周期、痛觉、情绪及激素水平的影响．实验结果表明,对比地磁场中饲喂对照组,亚磁场中小鼠的昼夜饮水节律改变、热敏痛觉耐受能力和整体活动水平降低,但是没有发生焦虑或抑郁情绪．亚磁场处理后,小鼠血清去甲肾上腺素水平显著下降． 这些结果说明一个月连续亚磁场处理扰乱动物的昼夜活动节律和内分泌,随后可能导致其感知觉能力的变化和运动机能的下降．     

色氨酸对应激小鼠行为学和脑内单胺类递质的影响

本文以小鼠为实验材料建模,依次进行了Morris水迷宫、跳台、强迫游泳实验。结果显示,应激可导致小鼠学习记忆能力下降,容易出现绝望情绪,下丘脑5-HT含量下降,NE含量上升,灌胃高低剂量色氨酸(100,200mg·kg-1 bw)均可显著提高小鼠学习记忆能力,缓和绝望情绪。低剂量色氨酸在增加下丘脑5-羟色胺(5-HT)含量和降低去甲肾上腺素(NE)含量方面效果更显著。结果表明,适量色氨酸可以有效改善应激小鼠相关行为学评分,其机制可能与下丘脑5-HT和NE的含量有关。     

小鼠颌下腺的交感神经支配的性差异

成年小鼠颌下腺的交感神经支配有显著的性差异:雄性小鼠颌下腺内的肾上腺能神经末梢基丛的荧光素较雌性小鼠的粗而明亮。用生化方法测定的颌下腺去甲肾上腺素含量,以整个腺体计,在雄性小鼠为225.39毫微克,在雌性小鼠为111.05毫微克;以每克腺体计,雄性为4.18微克,雌性为2.91微克。但成年小鼠虹膜内和幼年小鼠颌下腺内去甲肾上腺素含量无性差异。 多次注射丙酸睾酮后,雌性成年小鼠的颌下腺内去甲肾上腺素含量上升到同年龄的雄性小鼠的水平;多次注射异丙基肾上腺素后,雄性小鼠腺体内的去甲肾上腺素总量不变。 成年雄性小鼠的颌下腺内有较丰富的交感神经末梢,显然与成年雄性小鼠的颌下腺有高度分化的卷曲小管,产生大量的神经生长因子(NGF)有关。由于虹膜的去甲肾上腺素含量没有性差异,颌下腺NGF的作用途径看来是通过神经末梢摄取,经轴突逆向运输到达细胞体,而不是通过血液循环。     

亚磁场引起小鼠昼夜节律改变和热痛觉敏感增加（英文）

地外空间的亚磁场环境是影响宇航员健康的一种潜在风险因素.动物和人体实验表明,亚磁场显著影响个体行为和神经系统功能.但是,目前尚缺乏亚磁场对动物行为和生理等多方面影响的系统检测数据.本文构建了一个适用于动物饲养的亚磁场环境(500 n T),并系统检测了30天亚磁场处理对成年雄鼠(C57BL/6,4~6周龄,(20±2)g)的昼夜周期、痛觉、情绪及激素水平的影响.实验结果表明,对比地磁场中饲喂对照组,亚磁场中小鼠的昼夜饮水节律改变、热敏痛觉耐受能力和整体活动水平降低,但是没有发生焦虑或抑郁情绪.亚磁场处理后,小鼠血清去甲肾上腺素水平显著下降.这些结果说明一个月连续亚磁场处理扰乱动物的昼夜活动节律和内分泌,随后可能导致其感知觉能力的变化和运动机能的下降.     

中药天年饮对衰老大鼠脑单胺类神经递质含量的影响

目的：观察中药天年饮（Tiannianyin,TNY-traditional chinese medicine）对D-半乳糖衰老大鼠脑单胺类神经递质去甲肾上腺素（NE）、多巴胺（DA）、5-羟色胺（5-HT）含量的影响。方法：选用成年雄性SD大鼠40只．随机分为4组．每组均为10只：正常组、衰老模型组、TNY用药组、阴性对照组。Ⅱ半乳糖连续腹腔注射制作亚急性衰老的大鼠模型．采用高效液相色谱-电化学法检测各组大鼠下丘脑、海马NE、DA、5-HT的含量。结果：D-半乳糖衰老大鼠下丘脑、海马NE、DA、5-HT的含量明显降低（与正常大鼠相比P〈0．01）：TNY可明显提高脑单胺类神经递质的含量（用药组与模型组相比P〈0．05）。结论：TNY可有效调整中枢神经递质的合成,具有良好延缓衰老的作用。     

成年小鼠血液系统对亚磁场的响应

目的:研究亚磁场对成年小鼠血液系统的影响。方法:将成年雄性C57BL/6小鼠(4-6周,20±2g,n20,每笼4只)随机分组,分别饲养在模拟亚磁场环境(500nT)和对照地磁场环境(~50μT)。每周定时监测动物体重变化和饮食消耗两次。一个月后,采集亚磁处理小鼠和地磁对照小鼠全血和血清样品,分别进行血常规监测和血清微量元素分析。同时检测血清中过氧化氢(H2O2)的含量,以及超氧化物歧酶(SOD)和过氧化氢酶(CAT)的活力。结果:亚磁场处理过程中,动物体重和饮食消耗与地磁对照没有显著差异,但是体重增量在2周后(14天-24天)比对照组有显著降低(P0.05)。一个月亚磁场处理后,红细胞,血小板和总白细胞处于正常水平,没有发生显著变化,但是中性粒细胞水平显著上升(P0.05)。血清中微量元素水平和氧化应激指标没有显著变化。结论:成年小鼠在亚磁场中经历了一定程度的适应反应。经过一个月连续亚磁场处理,血液系统能够维持健康水平,但是嗜中性粒细胞对亚磁场存在明显响应。     

卵巢激素撤除诱发雌性小鼠抑郁样状态（英文）

目的：建立卵巢激素撤除诱发雌性小鼠抑郁样状态模型,并且探讨其可能的神经化学机制。方法：将小鼠分为假手术组,卵巢摘除组,己烯雌酚治疗组和氟西汀治疗组。动物行卵巢摘除术后开始给药,术后两周进行强迫游泳试验及悬尾试验以考察其抑郁样状态,并利用高效液相结合电化学检测测定下丘脑及海马中去甲肾上腺素（NE）、多巴胺（DA）以及五羟色胺（5-HT）的含量。结果：在强迫游泳试验及悬尾试验中,卵巢摘除小鼠较假手术组小鼠不动时间显著延长。神经递质测定显示,卵巢摘除小鼠下丘脑中NE与DA的含量显著降低,海马中NE与5-HT的含量显著降低。给予己烯雌酚或氟西汀治疗对抗了卵巢摘除所诱导的抑郁样状态,并且缓解了神经递质水平的下降。结论：双侧卵巢摘除诱发的小鼠抑郁样状态可以模拟妇女更年期抑郁的某些症状。本研究对于探讨卵巢激素撤除诱发抑郁状态的神经生化机制可能具有重要的意义。     

R~3中的一类拟齐次向量场的性质

利用三维拟齐次向量场和三维齐次向量场之间的等价关系并借鉴对齐次向量场的研究方法,把齐次向量场的一些结论推广到拟齐次向量场.并运用这些理论分析了具有不同增长率的三种群竞争模型的动力学性质和生物意义,得到增长率最大的种群在此竞争系统中占优,增长率最小的种群在此竞争系统中灭绝的结论.     

关于生态场的几点评述

依据植物生态场的系统研究资料,对生态场的概念、场的特征函数、生态场的图形以及生态场对植物相互作用的解释进行了评述.阐明了生态场的最基本属性是物质性,目前的研究水平尚不能确定生态场是否是有别于一般物理场的特殊形式的场.对生态场的基本特征函数-生态势模型给予了形式与模型参数估测方面的评述,表明两种生态势模型各有一定的特点与优越性.作者强调,生态场更具生态学的方法论意义,应用生态场对植物相互作用形式与过程的分析描述,具有定量化、综合性与直观化特点.生态场的绘图为生态学研究开辟了新的途径,特别是应用生态场理论分析群体植物的动态变化过程(由互利共存到干涉竞争)会有合理的定量解释.     

Evaluation of changes in diatom mobility after exposure to 16-Hz electromagnetic fields

The effect of a 16-Hz electromagnetic field on the mobility of the diatom Amphora coffeaformis was examined on agar plates that contained no added calcium and also on agar plates containing 0.25 or 2.5 mM exogenous Ca2+. Exposure conditions consisted of an ac field of 16 Hz with an amplitude of 20.9 microT parallel to the horizontal component of the dc field (BH = 20.9 microT, where BV = 0). To assess results, the percentage of diatoms that moved a distance greater than their body length was determined. We observed the field-associated increase in diatom motion at 0.25 mM Ca++, which was previously reported in the literature. Although the magnitude of the effect at 16 Hz was significant, the percentage of cells that moved was not sufficiently reproducible to allow examination for frequency dependence.     

关于生态场的几点评述

依据植物生态场的系统研究资料,对生态场的概念、场和特征函数、生态场折图形以及生态场对植物相互作用的解释进行了评述。阐明了生态场的最基本属性是物质性,目前的研究水平尚不能确定生态场是还是有别于一稻物理场的特殊形式在场,对生态场的基本特征函数－生态热模型给予了形式与模型参数体测方面的评述,表明两种生态势模型各有一定的特点与优越性。作者强调,生态场更具生态学的方法论意义,应用生态场对植物相互作用形式与过     

Distribution of sound pressure around a singing cricket: radiation pattern and asymmetry in the sound field

Male field crickets generate calls to attract distant females through tegminal stridulation: the rubbing together of the overlying right wing which bears a file of cuticular teeth against the underlying left wing which carries a sclerotized scraper. During stridulation, specialized areas of membrane on both wings are set into oscillating vibrations to produce acoustic radiation. The location of females is unknown to the calling males and thus increasing effective signal range in all directions will maximize transmission effectiveness. However, producing an omnidirectional sound field of high sound pressure levels may be problematic due to the mechanical asymmetry found in this sound generation system. Mechanical asymmetry occurs by the right wing coming to partially cover the left wing during the closing stroke phase of stridulation. As such, it is hypothesized that the sound field on the left-wing side of the animal will contain lower sound pressure components than on the right-wing side as a result of this coverage. This hypothesis was tested using a novel method to accurately record a high-resolution, three dimensional mapping of sound pressure levels around restrained Gryllus bimaculatus field crickets singing under pharmacological stimulation. The results indicate that a bilateral asymmetry is present across individuals, with greater amplitude components present in the right-wing side of the animal. Individual variation in sound pressure to either the right- or left-wing side is also observed. However, statistically significant differences in bilateral sound field asymmetry as presented here may not affect signalling in the field.     

Possible Mechanism for Synchronized Detection of Weak Magnetic Fields by Nerve Cells

We propose that biological systems may detect static and slowly varying magnetic fields by the modification of the timing of firing of adjacent nerve cells through the local influence of the magnetic field generated by current from one cell's firing on its nearest neighbors. The time delay of an adjacent nerve cell pulse with respect to the initial clock nerve cell pulse could serve as a signal for sensing the magnitude and direction of the magnetic field in a direction perpendicular to the current flows in the cells. It has been shown that changes in static magnetic fields modify concentrations of reactive oxygen species, calcium, pH, the growth rates of fibrosarcoma cells, and membrane potentials. These are linked to changes in membrane potentials that can either inhibit or accelerate the firing rate of pacemaker or clock cells. This mechanism may have applications to animals' use of magnetic fields for navigation or other purposes, possibly in conjunction with other mechanisms. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.     

A dosimeter for assessment of exposures to ELF fields

There are currently no biological indicators of electromagnetic field exposure to aid investigation of the biological effects of ELF fields, but this hiatus is partly compensated for by the ease with which the external fields can be measured. The subject of this report is a small electronic instrument that can log electric-, magnetic-, and transient-field intensities of individual subjects for a duration of two weeks, thus allowing exposure to be assessed in considerable detail. A preliminary survey conducted with the instrument has shown clear differences in domestic and occupational exposures of specific groups. Simple analytical models can be fitted to the field-exposure data by adjusting a few parameters such as current, intensity, and distance. Such modeling may be increasingly useful as the data base on exposures expands.     

Effect of magnetic fields on antioxidative defense and fitness-related traits of Baculum extradentatum (insecta, phasmatodea)

This study aimed to determine the effect of magnetic fields on the antioxidative defense and fitness-related traits of Baculum extradentatum. Following exposure to magnetic fields, antioxidative defense (superoxide dismutase (SOD), catalase (CAT) activities, and total glutathione (GSH) content) and fitness-related traits (egg mortality, development dynamics, and mass of nymphs) were monitored in nymphs. The experimental groups were: control (kept out of influence of the magnets), a group exposed to a constant magnetic field (CMF) of 50 mT, and a group exposed to an alternating magnetic field (AMF) of 50 Hz, 6 mT. We found increased SOD and CAT activities in animals exposed to constant and AMFs, whereas GSH activity was not influenced by experimental magnetic fields. No differences were found in egg mortality between control and experimental groups. Significant differences in the time of development between the control and the CMF group were observed, as well as between the CMF and the AMF group. No differences were found in the mass of the nymphs between the three experimental groups. In conclusion, CMF and AMF have the possibility to modulate the antioxidative defense and some of the fitness-related traits in B. extradentatum.