刺激下丘脑对猫小脑皮层神经元电活动的影响

在戊巴比妥钠麻醉的猫上观察了电刺激下丘脑外侧区（ＬＨＡ）、背侧区（ＤＨＡ）、后侧区（ＰＨＡ）和腹内侧核（ＶＭＮ）对小脑皮层第Ⅵ和Ⅶ小叶两类不同神经元（浦肯野细胞和非浦肯野细胞）电活动的影响。结果如下：①刺激ＬＨＡ、ＤＨＡ、ＰＨＡ和ＶＭＮ可引起不脑皮层神经元三种不同类型的反应，但以抑制反应为主（８０．８％，８４／１０４）；反应的潜伏期为１０－９０ｍｓ，并且半数细胞（５１％）对刺激呈现〈２０ｍｓ的短潜     

乙酰胆碱对家鸽顶盖脑片中Ⅲ层神经元电活动的影响

实验在２２只家鸽的离体顶盖脑片上，用玻璃微电极胞外记录到顶盖Ⅲ层神经元自发放电单位５０个，观察了乙酰胆碱（ＡＣｈ）及其拮抗剂以及电刺激Ⅱａ－ｆ亚层对Ⅲ层神经元电活动的作用。结果显示，脑片灌流ＡＣｈ（１０＾－６ｍｏｌ／Ｌ，３ｍｉｎ）后，２４／３７个单位（６４．９％）放电频率增加。４／３７个单位（１０．８％）放电频率降低，７／３７个单位（１８．９％）无明显变化，另２／３７个单位表现为先增频后减频反应。     

电刺激大鼠mPFC对听皮层神经元听反应的影响

实验在40只成年SD大鼠上进行,使用常规电生理学方法,观察了电刺激大鼠内侧额叶前皮质(medial prefrontal cortex, mPFC)对听皮层神经元听反应的影响.在122个神经元上观察了电刺激mPFC对听反应的影响.对其中93个神经元作了详细分析发现,有73个神经元的听反应受到易化（39个,41.9%）或抑制（34个,36.6%）.刺激mPFC对听反应的影响存在最佳刺激间隔,大多数神经元（51个,69%）在10~15 ms之间.结果提示,大鼠mPFC可对听皮层神经元的听反应调制,这种调制可能是通过多级神经元环路实现的.     

Si^＋／As^＋双离子注入SI—GaAs对注入层电激活均匀性改？…

研究了单（Ｓｉ＾＋）双（Ｓｉ＾＋／Ａｓ＾＋）离子注入半绝缘砷化镓电激活的均匀性,结果表明,ＬＥＣＳｉ－ＧａＡｓ衬底中深电子陷阱能级均匀性分布好坏,对注入层电激活性有一定影响,当ＳＩ－ＧａＡｓ中碳含量小于５＊１０＾１５ｃｍ＾－３时,对注入层电激活影响不大,采用多重能量Ｓｉ＾＋注入,可改善栽流子纵向分布的均匀性,采用Ｓｉ＾＋／Ａｓ＾＋双离子注入可改善ＬＥＣ ＳＩ－ＧａＡｓ衬底中ＥＬ２横向不均匀分布对电     

γ—氨基丁酸对家鸽（Columba livia）顶盖脑片Ⅲ层神经？…

在２５只家鸽的离体顶盖脑片上，用玻璃微电极胞外记录到顶盖Ⅲ层神经元自发放电单位５５个，观察了γ－氨基丁酸９ｇａｍｍａ－ａｍｉｎｏｂｕｔｙｒｉｃ，ＧＡＢＡ）及其拮抗剂以及电刺激Ⅲα￣ｆ亚层对Ⅲ岐神经元电活动的作用。作用显示：脑片灌流ＧＡＢＡ（１０＾－６ｍｏｌ／Ｌ，３ｍｉｎ）后，１６／２１个单位（占７６．２％）放电频率减少，１／２１个单位（占４．８％）放电频率增加，４／２１个单位（占１９．６％）放电频     

电刺激腹中隔区对IL—1β作用下兔POAH温敏神经元放电特性的影响

目的：进一步探讨中枢解热机理,方法：采用微电极细胞外记录,观察在致热原IL－1β作用下电刺激兔腹中隔区（VSA）对视前区下丘脑前部（POAH）温度敏感神经元放电特性的影响,结果：（1）IL－1β使热敏神经元放电频率减少时,电刺激腹中隔区可明显降低POAH热敏神经元的温度敏感系数,（2）IL－1β使冷敏神经元放电频率增加时,电刺激腹中隔区可增加POAH冷敏神经元的温度敏感系数。结论：作为负调节中枢的VSA可通过影响致热原作用下POAH区温敏神经元放电特性而解热。     

基于TMAES对GrC神经元放电活动影响的仿真

经颅磁声电刺激（TMAES）是一种新型无创的脑神经调控技术,具有良好的应用前景.该技术利用静磁场和超声波共同作用所产生的磁声电效应,在神经组织中产生感应电流,进而对神经组织实施刺激.作者基于小脑颗粒细胞模型（GrC模型）,建立了突触连接GrC模型,对TMAES刺激下突触连接GrC模型的动作电位进行仿真,分析了动作电位的传播方向.在TMAES神经元的不同突触连接方式下,对比了兴奋性与抑制性对神经元放电的影响.通过改变抑制点的位置分析了抑制作用在TMAES下对神经元放电模式的影响.仿真结果显示,经颅磁声电刺激对GrC模型神经元放电节律具有重要影响.实现了两个神经元突触连接模型在TMAES下的仿真,对进一步发掘和研究神经元的传导及连接模式具有重要意义.     

野木瓜注射液对爪蟾坐骨神经传导的影响

野木瓜注射液（Ｉｎｊｅｃｔｉｏｎｓｔａｕｎｔｏｎｉａｅ，ＩＳ）涂布于脊爪蟾（ＸｅｎｏｐｕｓＬａｅｖｉｓ）坐骨神经４ｍｍ长的一段上．电刺激跗部皮肤，记录半膜肌肌电．１０％ＩＳ使肌电的潜伏期和问期分别延长（１．５１±１．１５）ｍｓ和（２６．６±１６．１）ｍｓ（Ｐ＜０．０１，ｎ＝９）；５０％ＩＳ则使潜伏期延长（２．８４±２．１８）ｍｓ和幅度下降到原来的０．２１±０．２６（Ｐ＜０．０１，ｎ＝７）．ＩＳ对神经传导的阻滞作用是量效关系，给药８ｍｉｎ后电刺激坐骨神经干能使已受５０％ＩＳ影响而刺激跗部皮肤几乎不再引起肌电的半膜肌产生同对照一样的肌电．这表明在给药期内５０％ＩＳ主要阻滞传入纤维的传导，而不影响传出纤维的功能．     

γ-氨基丁酸参与家鸽顶盖的视网膜抑制性传入作用的离体研究

在６０例家鸽顶盖脑片上,利用胞外记录研究了γ－氨基丁酸（γ－ａｍｉｎｏｂｕｔｙｒｉｃ ａｃｉｄ,ＧＡＢＡ）和荷包牡丹碱（ｂｉｃｕｃｕｌｌｉｎｅ,ＢＩＣ）对顶盖视网膜接受区神经元自发放电及刺激Ⅰ层诱发的抑制反应的影响,灌流ＧＡＢＡ（１－１０ｍｍｏｌ／Ｌ）抑制了６０个神经元中的５２个神经元的电活动,这些抑制效应呈剂量依赖关系,ＧＡＢＡ的抑制效应绝大部分可被ＧＡＢＡＡ受体拮抗剂ＢＩＣ所阻断。单独灌流ＢＩ     

非鸣禽发声控制核和神经内分泌下丘脑区的神经联系

应用ＰＨＡＬ（Ｐｈａｓｅｏｌｕｓｖｕｌｇａｒｉｓｌｅｕｃｏａｇｇｌｕｔｉｎｉｎ）和荧光金（ｆｌｕｏｒｏｇｏｌｄ，）顺、逆行神经示踪及免疫组织化学方法对环鸽中脑发声控制核内丘核内侧亚核（ｍＩＣｏ）和下丘脑前内侧核（ＡＭ）的神经联系进行了研究。ＰＨＡＬ顺行神经示踪的标记结果表明，在含有丰富脑啡肽（ｍｅｔ－ｅｎｋｅｐｈａｌｉｎ，ｍｅｔ－ＥＮＫ）阳性免疫反应神经元的ｍＩＣｏ和内分泌下丘脑间存在一条直接神经通路。应用ｍｅｔ－ＥＮＫ和荧光金双重标记的研究结果表明，从ｍＩＣｏ向ＡＭ投射的荧光金标记细胞中的５％～１５％是ｍｅｔ－ＥＮＫ免疫反应神经元。这些结果提示，ｍＩＣｏ中的部分ｍｅｔ－ＥＮＫ神经元参与了ＡＭ的传出神经投射通路，这条神经通路可能对鸟类发声、听觉和内分泌系统间相互作用的调制具有一定作用。     

基于多元线性逆滤波器的视顶盖神经元集群亮度信息解码研究

通过解码鸽子视顶盖(the optic tectum,OT)神经元集群亮度信息的方法,研究了OT区神经元集群编码亮度信息的神经机制。首先设计了具有瞬态闪变特性的亮度视觉刺激模式,采用微电极阵列记录了多通道的锋电位(spike)发放序列;然后提取了神经元集群的spike发放率特征,构造多元线性逆滤波器解码视觉刺激亮度;最后采用互相关和信息论的方法对解码结果进行了分析。结果表明:采用的多元线性逆滤波器有效解码了OT区神经元集群编码的亮度信息。通过对解码参数变化与解码精度的分析可知神经元集群数目13个、bin的宽度5 ms、刺激后15 ms、刺激后持续时间35 ms具有最高的解码精度。通过神经元集群中逆滤波器形态的分析发现,单神经元在亮度信息的编码过程中受周围神经元的动态调制。通过对解码精度与刺激闪变频率关系的分析,发现在刺激闪变频率19 Hz到53 Hz的范围内,重建质量较好,在刺激闪变频率为33.5 Hz时,重建质量达到最优。     

地产平面广告的视觉表现形式对受众注意的影响

本文以房地产平面广告为研究对象,通过分析它的视觉表现形式对受众注意产生的作用,揭示不同的广告表现形式对广告传播效果的影响。     

鱼眼视频图像畸变的实时校正方法

采用鱼眼图像的球面投影模型,提出一种基于鱼眼透镜球面投影的实时校正方法.该方法将鱼眼图像映射在5个图像平面上,解决了鱼眼视频图像畸变严重,观测视觉体验效果较差的问题;根据图像在计算机中的内存布局,对校正算法中的空间映射计算和内存存储空间进行了优化,提高了算法的执行效率,减少了算法的内存消耗.实验结果表明,该方法能显著改善鱼眼图像的显示效果,对单帧图像的处理时间仅为18.37ms,能满足鱼眼视频图像实时校正的需要.     

视、听偏差刺激选择性注意的ERPs研究

本实验采用了视听双通道伪同时呈现的oddball模式,以汉字和简单几何图形为视觉刺激,1000Hz和800Hz的纯音为听觉刺激,使用注意通道(注意和非注意条件)×刺激概率(偏差刺激概率均为15%,标准刺激的概率均为85%)的2×2因素设计,来研究视觉和听觉偏差刺激在注意和非注意条件下诱发的事件相关电位(ERPs)。实验中视觉和听觉刺激随机序列地呈现给被试(刺激间隔ISI为700～1300ms),被试被要求注意某一通道如视觉通道,而相应地忽视另一通道即听觉通道,以左右手触键反应,如左手反应视觉偏差刺激,右手反应视觉标准刺激。结果表明,听觉偏差刺激在注意和非注意条件下均诱发了类似的不匹配负波(MMN);而视觉偏差刺激在注意和非注意条件下没有诱发MMN或类似MMN的成分,这是因为视觉系统的平行加工特性和难以对视觉影像产生记忆痕迹。听觉偏差刺激在注意条件下重迭了N2b成分并跟随了P3a成分,这种重迭和跟随反映了选择注意中的定向反应。注意条件下听觉和视觉的偏差刺激诱发了较大波幅的P300成分,反映了工作记忆中的表象更新。本实验的结果支持Naatanen对MMN所做的观察,听觉偏差刺激所诱发的MMN与注意条件的无关性反映了听觉通道中感觉刺激特征的自动化加工。     

Millisecond activation of transducin in the cyclic nucleotide cascade of vision

Cyclic GMP has been implicated as a messenger molecule involved in visual transduction. Photoexcited rhodopsin (R*) binds to a multisubunit membrane protein called transducin (T) and stimulates the exchange of a bound GDP molecule for GTP. This leads to the release of the alpha-subunit of T with bound GTP (T alpha-GTP), which activates a cyclic GMP phosphodiesterase. The question arises as to whether the hydrolysis of cyclic GMP that results from activation of the phosphodiesterase is sufficiently rapid to be involved in visual excitation, which occurs on a time scale of approximately 2 s in the single-photon limit. Previous studies have suggested that the cyclic GMP phosphodiesterase is activated in less than 100 ms at moderate light levels. We report here light scattering studies of magnetically orientated frog rod outer segments which show that a molecule of R* catalyses the activation of a molecule of T in about 1 ms. Thus, hundreds of molecules can be activated within the response time of vision in the single-photon limit, and the formation of T alpha-GTP is fast enough for it to be a key step in visual transduction.     

Sustained division of the attentional spotlight

By voluntarily directing attention to a specific region of a visual scene, we can improve our perception of stimuli at that location. This ability to focus attention upon specific zones of the visual field has been described metaphorically as a moveable spotlight or zoom lens that facilitates the processing of stimuli within its 'beam'. A long-standing controversy has centred on the question of whether the spotlight of spatial attention has a unitary beam or whether it can be divided flexibly to disparate locations. Evidence supporting the unitary spotlight view has come from numerous behavioural and electrophysiological studies. Recent experiments, however, indicate that the spotlight of spatial attention may be divided between non-contiguous zones of the visual field for very brief stimulus exposures (&<100 ms). Here we use an electrophysiological measure of attentional allocation (the steady-state visual evoked potential) to show that the spotlight may be divided between spatially separated locations (excluding interposed locations) over more extended time periods. This spotlight division appears to be accomplished at an early stage of visual-cortical processing.     

显示器画面排布和信息提示对监控效率的影响

基于眼动跟踪技术,通过实验操控和设计,记录被试在监控显示器分画面有无间隙下以及分画面的不同排布序列下的眼动数据。并结合调查问卷分析视觉搜索效率,探讨监控管理流程中是否给予监控人员提示对监控效率的影响。结果表明,采用有间隙的、水平序列的监控分画面排布时,监控人员发现问题画面的效率更高,被试对有间隙监控界面的平均注视时长（42 183 ms）显著小于无间隙界面的（53 480 ms）,对水平序列监控界面的平均注视时长（2 6899 ms）显著小于无间隙界面的（5 4925 ms）;在给予监控人员信息提示下,监控效率显著提高。建议企业从3方面优化监控管理流程:在监控界面各分界面之间留有间隙;监控界面的各分画面的序列方式采取水平向序列;监控管理流程中应对监控人员给予合适的提示。     

An event-related potential study of working memory in children

Working memory refers to temporary storage and manipulation of “on-line” information in the brain,which is central to a large range of cognitive capabili- ties[1]. Visual working memory involves processes such as maintaining, updating and manipulating b…     

Neural mechanisms of perceptual grouping in human visual cortex

The current work examined neural substrates of perceptual grouping in human visual cortex using event-related potential (ERP) recording. Stimulus arrays consisted of local elements that were either evenly spaced (uniform stimuli) or grouped into columns or rows by proximity or color similarity (grouping stimuli). High-density ERPs were recorded while subjects identified orientations of perceptual groups in stimulus arrays that were presented randomly in one of the four quadrants of the visual field.Both uniform and grouping stimulus arrays elicited an early ERP component (C1), which peaked at about 70ms after stimulus onset and changed its polarity as a function of stimulated elevations. Dipole modeling based on realistichead boundary-element models revealed generators of the C1 component in the calcarine cortex. The C1 was modulated by perceptual grouping of local elements based on proximity, and this grouping effect was stronger in the upper than in the lower visual field. The findings provide ERP evidence for the engagement of human primary visual cortex in the early stage of perceptual grouping.     

Neuronal switching of sensorimotor transformations for antisaccades

The influence of cognitive context on orienting behaviour can be explored using the mixed memory-prosaccade, memory-antisaccade task. A symbolic cue, such as the colour of a visual stimulus, instructs the subject to make a brief, rapid eye movement (a saccade) either towards the stimulus (prosaccade) or in the opposite direction (antisaccade). Thus, the appropriate sensorimotor transformation must be switched on to execute the instructed task. Despite advances in our understanding of the neuronal processing of antisaccades, it remains unclear how the brain selects and computes the sensorimotor transformation leading to an antisaccade. Here we show that area LIP of the posterior parietal cortex is involved in these processes. LIP's population activity turns from the visual direction to the motor direction during memory-antisaccade trials. About one-third of the visual neurons in LIP produce a brisk, transient discharge in certain memory-antisaccade trials. We call this discharge 'paradoxical' because its timing is visual-like but its direction is motor. The paradoxical discharge shows, first, that switching occurs already at the level of visual cells, as previously proposed by Schlag-Rey and colleagues; and second, that this switching is accomplished very rapidly, within 50 ms from the arrival of the visual signals in LIP.