动物离心机中大鼠行为状态无线视频采集装置的研制

目的:研制一种在正加速度作用下能实时观测大鼠行为状态的实验视频采集装置,为研究正加速度导致脑损伤的病理生理机制和防治措施提供新的方法。方法:依据正加速度对大鼠体位的要求和离心机特殊的环境,通过特制的大鼠座舱和无线视频采集单元来实现对动物离心机中正加速度作用下大鼠行为状态的实时观测;固定大鼠的座舱主要由胸部固定圈、身长调节圈、头部运动限制框构成;无线视频采集单元由2.4 G无线摄像头、无线信号接收器、信号放大器、计算机以及视频采集软件组成。结果:座舱特殊的大鼠固定方式,既满足了正加速度对体位的要求,又不影响对大鼠行为状态的观测,2.4 G无线视频采集技术保证视频信号在离心机高速旋转环境下的实时传输和观测,视频画面清晰流畅,并且能保存视频供回放分析。结论:动物离心机无线视频采集装置可用于正加速度作用下大鼠行为状态的实时观测与研究。     

基于前额联络皮层脑电信号的海洛因戒断大鼠个体觅药行为状态识别*

目的: 探究海洛因诱导位置偏爱大鼠不同行为状态下额叶联络皮层(FrA)无线遥测脑电新的分析方法,以期能精确实时识别海洛因诱导大鼠个体的强迫性觅药行为。方法: 清洁级 Wistar大鼠30只,于前额皮层行电极埋藏术后,随机分为手术对照组(n=10)和海洛因诱导组(n=20);海洛因诱导组皮下注射海洛因0.5 mg/(kg·d),之后每日递增0.25 mg/kg,连续注射7 d,对照组同时间注射等量生理盐水;利用 CPP 视频系统结合脑电无线遥测技术,同步记录白-黑箱穿梭、黑箱停留、黑-白箱穿梭、白箱停留四种行为状态下已成瘾大鼠FrA区脑电信号,辨识原始脑电中含肌电等噪声信号区域,针对性的给以小波分解及振幅阈值消噪预处理,提取不同行为状态下脑电数据的样本熵值及与4个节律频率对应的小波系数标准差值,利用支持向量机算法(SVM)实现对海洛因成瘾大鼠个体不同行为状态的实时识别。结果: SVM对20只经海洛因诱导产生明显药物依赖的大鼠个体白-黑穿梭、黑箱停留、黑-白穿梭、白箱停留四种不同行为状态的实时分类识别率均值都达到80%左右,其中与觅药行为关联最紧密的黑-白穿梭状态实时识别率均值达到83.88%。结论: 本文建立的对海洛因诱导大鼠个体强迫性觅药行为的实时识别方法,可作为一种检测海洛因大鼠觅药行为发动、发生的有效手段,可用于海洛因依赖患者的临床观察和觅药行为的预防。     

反复正加速度暴露后大鼠心肌的细胞凋亡改变

目的：探讨不同水平的1周重复多次的正加速度（＋Gz）暴露后大鼠心室肌凋亡的现象及变化规律。方法：12只雄性SD大鼠随机分为＋6Gz组,＋10Gz组和对照组,每组4只：＋Gz组大鼠分别暴露于＋6Gz／3min和＋10Gz／3min,1次／d,连续暴露1周;对照组大鼠置于离心机室,但不受加速度作用。大鼠于末次暴露后1天,取左心室,采用透射电镜和末端脱氧核苷酸转移酶介导的dUTP缺口标记技术观察心肌细胞凋亡情况。所有实验数据进行方差分析及LSD—t检验。结果：电镜下,除＋10Gz组可观察到心肌细胞核内异染色质增多、浓缩、边集现象外,各组未见典型的凋亡改变。TUNEL染色可见,＋6Gz组、＋10Gz组大鼠心肌细胞凋亡指数较对照组均显著增高（F=42．47,t6G=5．04;t10G=7．43,P〈0．01）;＋10Gz组大鼠心肌凋亡指数较＋6Gz组显著增多（t6G／10G=2．39,P〈0．05）。结论：＋Gz重复暴露可引起大鼠心肌细胞凋亡,且随着G值的增大,细胞凋亡指数呈增多趋势。     

大鼠压杆行为的运动皮层局部场电位研究

目的：提取与大鼠右前肢运动相关联的初级运动皮层场电位的信号特征,并探讨依据局部场电位（LFP）识别前肢运动行为的可行性。方法：4只SD大鼠通过训练习得压杆取水操作,然后在左右脑初级运动皮层M1区分别植入多通道束状微电极,术后恢复后进行大鼠压杆行为实验,以2 kHz/s速率记录深部脑电信号及压杆状态信号,同步记录行为过程的视频信号。以通道间的差分信号作为局部场电位信号,分析局部场电位信号的时域特征,进行聚类分析。以压杆状态信号和视频分析为判定依据,对聚类结果进行分析。结果：局部场电位信号在大鼠压杆动作时明显增强,不同通道的局部场电位信号幅值、波形有差异,表明与前肢运动相关联的M1区局部场电位信号有空间分布特征;依据阈值准则从局部场电位信号检测压杆行为的检出率为80%。结论：依据局部场电位信号特征对大鼠前肢运动进行检测具有可行性。     

离心机训练对大鼠脑和心脏组织基因表达的影响

 分析离心机训练对大鼠脑和心脏组织基因表达的影响 ,并从中筛选正加速度 (forwardaccel eration ,+Gz)高耐力相关基因 .雄性SD大鼠在动物离心机上训练 ,刺激G值从 + 7Gz～ + 12Gz ,每天增加 + 0 5Gz ,第 12d重复 + 12Gz刺激 ,第 13d在离心机上通过测定动物的 +Gz耐力筛选出高耐力动物 ,立即断头处死 ,取全脑和心脏组织 ,分离其mRNA .将此mRNA与未处理动物相应组织来源的mRNA进行抑制性消减杂交 (SSH) ,获得的相关EST(expressionsequencetag ,EST)进行序列测定 ,并经BLAST进行计算机分析 .结果获得 88条与离心机训练相关的EST ,其中 4 4条为已知基因的部分序列 ,4 4条为未知基因的部分序列 .提示离心机训练对大鼠脑和心脏组织基因表达有影响 ;这些相关基因可能与 +Gz高耐力的产生有关     

离心机训练对大鼠脑及其它组织IL-6和TNFα基因表达水平的影响

为了解离心机训练前后大鼠脑及心、肺、肾和小肠组织中IL 6和TNFα基因表达水平的变化 ,对雄性SD大鼠进行动物离心机训练 ,刺激值从 + 7Gz～ + 12Gz ,每天增加 + 0 5Gz ,第 12d重复 + 12Gz刺激 ,第 13d离心机训练后 ,断头处死 ,取心、脑、肺、肾和小肠组织 ,分别提取mRNA并定量 .用地高辛标记IL 6和TNFαcDNA作为探针 ,进行狭缝杂交 ,杂交结果通过光密度扫描定量后 ,进行统计学处理 .离心机训练不同时间 ,比较大鼠各组织IL 6和TNFα基因表达水平的变化 .结果显示随着训练时间的延长 ,表达水平均有所差异 .提示训练对大鼠脑及其它主要组织IL 6和TNFα基因表达水平有影响 ,这种影响可能与机体对加速度作用的习服有关     

自由活动大鼠睡眠呼吸监测技术改进

目的：改进大鼠睡眠呼吸监测技术,解决既往模型中咬线、脱落、信号不稳定问题。方法：改进监测电极、信号接入线路及动物手术。结果：改进后手术时间缩短,创面暴露时间减少,大鼠术后易恢复。且电极稳固性好,脑电和肌电信号更稳定清晰,信号接入线路传导性好,耐用。实现连续长时间监测,成功率高。便于根据信号进行不同清醒一睡眠状态分期,并判断大鼠睡眠呼吸暂停情况。结论：改进后的操作技术操作更简单、信号更稳定,是一项更加实用可靠的小动物睡眠呼吸监测技术。     

基于蓝牙4.0的便携式睡眠监测仪的研制

目的:实时监测睡眠状况,从而帮助人们特别是老人找到影响睡眠的原因。方法:设计了一个低功耗便携式睡眠监测仪,它是通过加速度传感器采集腕动信号、蓝牙4.0低功耗无线传输、Micro-SD卡存储、上位机显示等实现对睡眠状态的检测。为了验证睡眠监测仪的准确性,本文采用了视频分析方法,并且对不同人群进行监测。结果:研制的睡眠监测仪具有便携低功耗等特点,能够准确监测睡眠状态。结论:睡眠监测仪的研制对使用者特别是老人帮助很大,能够帮助使用者方便适时了解自己的睡眠状况,找到影响睡眠原因和改善睡眠质量方法。     

超声波清洗器对大鼠心电图的影响

目的考察超声波清洗器对大鼠的影响。方法用RM6240多道生理信号采集处理系统,采用标准肢体二导联法测量正常状态和超声波清洗器工作时麻醉大鼠的心电图。结果超声波清洗器打开后2 min、15 min和30 min时,麻醉大鼠的心率显著增加,心电图的QRS波群间期显著缩短。而超声波清洗器停止工作后30 min时,大鼠心率和QRS波群间期基本恢复至正常。结论超声波清洗器工作时对大鼠心脏可产生一过性的不良影响。因此,在动物饲养或实验区内,超声波清洗器的放置应远离大鼠饲养室。     

当潜标遇上冰山

正潜标是一种常用的海洋观测装置:用缆绳将各种观测仪器连接起来,上端配上浮球,下端连接释放器和重物,投放到海里,就构成了一套潜标。潜标下端由重物固定在海底,缆绳在浮球的浮力作用下保持竖直状态,上面的仪器在海洋的不同深度进行观测或取样。潜标放置一年后,科学家可以从海面发送信号,将释放器打开,仪器在浮球的牵引下升到海面。科研人员回收仪器后     

Comparison of anti-G trousers equipped with bladder and tightening system

Two different anti-G flight suits are compared. The first suit uses a bladder system to compress the lower limbs and abdomen and the second uses a tightening system to produce compression evenly for the lower body. Studies were performed using a centrifuge cabin with exposure to acceleration forces up to 2.5 G. Suits were compared for protection efficiency, comfort, complaints, and put on ease. Results of the study, including heart rate dynamics, ear vascular pulsation amplitude, and peripheral vision loss are presented.     

大鼠脑创伤后caspase-3的过度表达与细胞凋亡的关系

目的：探讨大鼠脑创伤后海马神经组织中casepase-3表达及其在细胞凋亡中的机制。方法：雄性Wistar大鼠72只随机分成对照组和创伤组。用Marmarou方法造成大鼠重型弥漫性颅脑创伤,采用免疫组织化学检测海马CA1区神经细胞casepase-3蛋白表达情况,原位细胞DNA断裂检测末端标记（TUNEL）法观察大鼠海马CA1区神经细胞凋亡动态变化。同时行TUNEL与caspase-3双标染色。结果：对照组海马区神经细胞casepase-3未见明显表达,创伤组海马CA1区神经细胞casepase-3表达在伤后3小时开始升高,伤后3天达高峰（P〈0．01）,伤后7天下降明显。对照组海马区未见TUNEL阳性细胞,创伤组海马区TUNEL阳性细胞伤后3小时开始增多,伤后3天达高峰（P〈0．01）,伤后7天下降。可见创伤组TUNEL染色与caspase-3免疫染色双标阳性的细胞伤后6小时细胞数量逐渐增多,于伤后3天达高峰（P〈0．01）,伤后7天双标阳性细胞数量下降。Casepase-3表达与TUNEL阳性细胞明显相关（P〈0．01）。结论：大鼠脑创伤后casepase-3的过度表达是影响大鼠脑创伤后神经细胞凋亡原因之一,抑制casepase-3活性表达对神经组织起保护作用。     

SPF级新生大鼠高氧肺损伤模型的建立

目的建立一种操作简便、性能稳定的新生大鼠高氧肺损伤动物模型。方法①设计制造能自动控制氧浓度的高氧动物饲养舱。②将孕期满21 d出生的SPF级新生大鼠随机分成4组,即：高氧组Ⅰ（入高氧舱中饲养1～7 d）,高氧组Ⅱ（入高氧舱中饲养14 d）,以及相应的空气对照组Ⅰ、Ⅱ,每组14只。舱内氧浓度≥90%,每天23 h。计算肺系数,HE染色与病理学观察。结果高氧组与相应的对照组比较：高氧组大鼠体重轻,肺系数大,HE染色显示部分肺泡萎缩、肺间质及肺泡腔有水肿、出血,中性粒细胞浸润;肺泡发育明显滞后,辐射状肺泡计数明显少。结论本动物饲养舱性能稳定,操作简便;复制的新生大鼠的肺病理变化符合高氧肺损伤的改变。     

-phenyl-tert-butyl-nitrone inhibits free radical release in brain concussion

Traumatic brain injury (TBI) is one of the important causes of mortality and morbidity. The pathogenesis of the underlying brain dysfunction is poorly understood. Recent data have suggested that oxygen free radicals play a key role in the primary and secondary processes of acute TBI. We report direct electron spin resonance (ESR) evidence of hydroxyl (·OH) radical generation in closed-head injury of rats. Moderate brain concussion was produced by controlled and reproducible mechanical, fixed, closed-head injury. A cortical cup was placed over one cerebral hemisphere within 20 min of the concussion, perfused with artificial cerebrospinal fluid (aCSF) containing the spin trap agent pyridyl-N-oxide-tert-butyl nitrone (POBN, 100 mM), and superfusate samples collected at 10 min intervals for a duration up to 130 min post brain trauma. In addition, POBN was administered systematically (50 mg/kg body wt.) 10 min pretrauma and 20 min posttrauma to improve our ability to detect free radicals. ESR analysis of the superfusate samples revealed six line spectra (_N = 15.4 and ^β_H = 2.5 G) characteristic of POBN-OH radical adducts, the intensity of which peaked 40 min posttrauma. The signal was undetectable after 120 min. Administration of -phenyl-tert-butyl-nitrone (PBN), a spin adduct forming agent systemically (100 mg/kg body wt. IP 10 min prior to concussion) alone or along with topical PBN (100 mM PBN in aCSF),6significantly (P< 0.001) attenuated the ESR signal, suggesting its possible role in the treatment of TBI.     

Effects of hypergravity on the photosynthetic flagellate, Euglena gracilis

Euglena gracilis, a unicellular, photosynthetic flagellate, orients itself by means of gravi- and phototaxis to reach and stay in regions optimal for survival and growth. An improved version of the slow rotating centrifuge microscope, NIZEMI, was used to test wild type and mutant strains for their responses to hypergravity. Wild type cells could actively move against the acceleration vector up to 8.5 gn and were centrifuged down at higher rates. Even at 10.5 gn, the highest value tested, cells were still negative gravitactically oriented as shown by video images. In contrast, all mutant strains as well as Astasia longa, a close relative of Euglena, could move against the acceleration vector under all conditions tested. With increasing accelerations the mean orientation of the populations shifted according to a vectorial addition of gravity and acceleration. The r-value, a statistical measure of the orientation of a population, increased with moderately increased acceleration rates and decreased at higher values. While wild type Euglena and two of the three mutant strains tested were exclusively negative gravitactically, in the third strain as well as in Astasia longa half of the population reacted negative gravitactically and the other half positive gravitactically. This variation of the wild type behavior was observed at moderate acceleration rates. At high accelerations the cells became exclusively positive gravitactic. The obtained results are discussed on the basis of the current model explaining gravitaxis.     

A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats

To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems.     

Effect of water load in human body systems upon tolerance to +Gz acceleration

A possible improvement of +Gz acceleration tolerance, obtained in human subjects through administering specific volumes of water, viz. 7, 14 and 21 ml/kg body weight, to be drunk immediately before centrifuge examination in order to increase the volume of plasma, thus increasing the circulating blood volume, was the starting-point for this work. Two hundred healthy male subjects, aged 19.9 +/- 0.9, were classified in 4 main groups and 2 supplementary groups for examination. It was found that the water intake in volumes of 14 ml/kg body weight produced a significant mean increase in the acceleration tolerance of 0.8 G, and that of 21 ml/kg body weight improved acceleration tolerance by 1.1 G on the average. The increase tolerance to acceleration was maintained throughout a period of about 30 minutes (for 14 ml/kg body weight) up to approximately 50 minutes (for 21 ml/kg body weight). The favourable effect of water load in the body systems upon +Gz acceleration tolerance was probably due to the increase of plasma volume (by 5.24% and 6.98% for 14 and 21 ml/kg body weight, respectively).