新生大鼠脊髓薄片中的运动神经元对腹外侧索刺激的反应

在新生大鼠脊髓薄片细胞内记录了２５个经送行刺激鉴定的运动神经元（ＭＮ）,发现腹外侧索刺激可在８０％的ＭＮ诱发去极化反应（ＥＰＳＰ）。在静息电位水平ＥＰＳＰ的潜伏期、达峰时间、幅度、半衰时间和时程分别为１．２±０．２ｍｓ,２．６±０．４ｍｓ,１３±３ｍＶ,５．３±１．６ｍｓ和３１±８ｍｓ。ＥＰＳＰ呈等级性和膜电位依赖性,平均翻转电位为－８ｍＶ,潜伏期在０．—５Ｈｚ频率的刺激时相对恒定,但刺激频率＞２０Ｈｚ时ＥＰＳＰ变小或被取消。ＥＰＳＰ在低钙高镁溶液中被阻抑叵在无镁溶液中增强。犬尿烯酸（０．５—１ｍｍｏｌ／Ｌ）可逆地阻断ＥＰＳＰ,但氯胺酮（５０—１００μｍｏｌ／Ｌ）仅部分抑制之。结果表明腹外侧索中的下行纤维可能释放兴奋性氨基酸而激活ＭＮ。     

脊髓中P物质参与电针镇痛的研究

本研究发现,低频（２Ｈｚ）电针刺激时大鼠脊髓中Ｐ物质免疫活性（ＳＰ－ｉｒ）含量减少,中频（１５Ｈｚ）、高频（１００Ｈｚ）和变频（２／１５Ｈｚ）刺激时ＳＰ－ｉｒ含量增多。脊髓蛛网膜下腔（ｉ．ｔ．）注射非肽类ＳＰ（ＮＫＩ）受体拮抗剂ＣＰ９６３４５和ＲＰ６７５８０均能阻断中频、高频和变频的电针镇痛。ｉ．ｔ．注射阿片拮抗剂纳洛酮阻断低频和中频刺激时ＳＰ－ｉｒ含量的变化。结果提示,脊髓ＳＰ－ｉｒ在低频时释放     

红颊骨骼的解剖研究

红颊骨骼的解剖研究ＡＮＡＴＯＭＩＣＳＴＵＤＩＥＳＯＮＴＨＥＳＫＥＬＥＴＯＮＳＹＳＴＥＭＯＦＨＥＲＰＥＳＴＥＳＡＵＲＯＰＵＮＣＴＡＴＵＳ红颊（Ｈｅｒｐｅｓｔｅｓａｕｒｏｐｕｎｃｔａｔｕｓ）是一种具有较高经济价值的小型哺乳动物,研究其骨骼的解剖结构...     

颗粒子宫腺细胞的分离、纯化与细胞化学研究

胰蛋白酶消化小鼠子宫腺细胞区,制成单细胞悬液,滴片后进行细胞学及细胞化学研究。结果：有多种类型细胞存在于悬液中,其中中等大小细胞（直径２０μｍ左右）大部分为颗粒子宫腺细胞（ＧｒａｎｕｌａｔｅｄＭｅｔｒｉａｌＧｌａｎｄＣｅｌｌｓ,ＧＭＧｃｅｌｌｓ）。ＧＭＧ细胞约占所有细胞的５０％。利用Ｐｅｒｃｏｌｌ非连续性密度梯度离心可以提高ＧＭＧ细胞的纯度,使之达８０％以上。细胞化学研究显示ＧＭＧ细胞含ＡＣＰ,ＮＳＥ,ＬＮＡｓｅ及糖蛋白成份。     

抗心律失常药UK－68798对家兔心脏房室结区不同细胞的电生理作用

在离体家兔ＡＶＮ区标本上,用微电极技术研究了Ⅲ类抗心律失常新药ＵＫ－６８７９８对ＡＮ,Ｎ,ＮＨ,Ｈ４种细胞的电生理效应。浓度５×１０－９至５×１０－６ｍｏｌ／Ｌ的ＵＫ－６８７９８对４种细胞的动作电位幅值（ＡＰＡ）、静息膜电位（ＲＰ）皆无影响。对ＡＶＮ的自搏率有剂量依赖性减慢作用,但不改变Ａ－Ｈ传导时间。在５×１０－８－５×１０－６ｍｏｌ／Ｌ剂量范围,此药使动作电位时程（ＡＰＤ５０）和（ＡＰＤ９０）发生剂量依赖性延长。４种细胞中以Ｎ细胞的ＡＰＤ５０和ＡＰＤ９０延长百分率最高。各种细胞ＡＰＤ９０延长百分率的排列次序为Ｎ＜ＡＮ＜Ｈ＜ＮＨ,当浓度为５×１０－６ｍｏｌ／Ｌ时的延长百分率分别为９５±２６％（Ｎ）,７５±２２％（ＡＮ）,６３±２６％（Ｈ）,４６±２６％（ＮＨ）。在ＵＫ－６８７９８的作用下,４种细胞的有效不应期（ＥＲＰ）也发生剂量依赖性延长,但不存在像ＡＰＤ延长百分率那样的差别。此外,４种细胞ＥＲＰ所相当的复极化膜电位未受药物影响,从而避免了由于兴奋性恢复的不均一性,使ＡＶＮ区成为折返性心律失常的发源地．     

鼠伤寒沙门氏菌外膜蛋白诱导BALB／C小鼠免疫保护的实验研究

本实验采用超声破碎、ＴｒｉｔｏｎＸ－１００处理和超速离心技术提取了鼠伤寒沙门氏菌（Ｓａｌｍｏｎｅｌｌａｔｙｈｉｍｕｒｉｕｍ,ＳＴＭ）的外膜蛋白（Ｏｕｔｅｒｍｅｍｂｒａｎｅｐｒｏｔｅｉｎｓ,ＯＭＰｓ）,其中脂多糖（ＬＰＳ）的含量约为５％。ＯＭＰｓ经ＳＤＳ—ＰＡＧＥ显示１０余条蛋白带。对ＯＭＰｓ诱发ＢＡＬＢ／Ｃ小鼠产生典型的迟发型变态反应（ＤＴＨ）进行了检测。经腹腔免疫的ＢＡＬＢ／Ｃ小鼠用５００ＬＤ５０鼠伤寒沙门氏菌（５０１１５）攻击,１００％可得到保护;用５００ＬＤ５０伤寒杆菌（Ｅ６８６）攻击     

中华姬鼠种群生态的初步分析

中华姬鼠种群生态的初步分析ＴＨＥＰＲＥＬＩＭＩＮＡＲＹＡＮＡＬＹＳＩＳＯＮＴＨＥＰＯＰＵＬＡＴＩＯＮＥＣＯＬＯＧＹＯＦＣＨＩＮＥＳＥＦＩＥＬＤＭＯＵＳＥ（ＡＰＯＤＥＭＵＳＤＲＡＣＯ）ＫｅｙＷｏｒｄｓＣｈｉｎｅｓｅＦｉｅｌｄＭｏｕｓｅ（Ａｐｏｄｅｍｕｓ...     

江豚和白鳍豚雄性生殖系统的解剖学研究

江豚和白鳍豚雄性生殖系统的解剖学研究ＯＮＴＨＥＡＮＡＴＯＭＹＯＦＴＨＥＭＡＬＥＧＥＮＩＴＡＬＳＹＳＴＥＭＩＮＴＨＥＢＡＩＪＩ（ＬＩＰＯＴＥＳＶＥＸＩＬＬＩＦＥＲ）ＡＮＤＦＩＮＬＥＳＳＰＯＲＰＯＩＳＥ（ＮＥＯＰＨＯＣＡＥＮＡＰＨＯＣＡＥＮＯＩＤＥＳ）...     

上下视野空间选择性注意的ERP研究

该文主要研究上、下视野空间选择性注意早期所诱发的ＥＲＰ反应,探讨注意上、下视野视觉信息处理的特征与差别。１０名被试的主要实验果为：１）对上、下视野的选择注意产生类似于注意左、右视野时Ｐ１、Ｎ１,Ｐ２的相对增强;２）偶极子定位显示,上、下视野刺激的早期注意反应（Ｐ１）以交叉方式投射到枕区,即下视野刺激的注意反应偏向枕区的背侧,而上视野刺激的注意反应偏向枕区的腹侧;３）上下视野的早期注意反应（Ｐ１）具     

盐生杜氏藻甘油-3-磷酸脱氢酶的分离纯化及其特性的研究

利用ＰＥＧ分级,ＤＥＡＥ离子交换层析,ＢｌｕｅＳｅｐｈａｒｏｓｅ拟亲和层析,ＭｏｎｏＱ离子交换层析等手段,分离纯化盐生杜氏藻（Ｄｕｎａｌｉｅｌａｓａｌｉｎａ（Ｄｕｎａｌ）Ｔｅｏｄ．）甘油三磷酸（Ｇ３Ｐ）脱氢酶（ＥＣ１．１．１．８）,得到比活为１２．６Ｕ／ｍｇ的电泳纯的酶,并对此酶的生化特性进行了研究。４％～２０％非变性聚丙烯酰胺梯度凝胶电泳测得全酶分子量约为２７０ｋＤ,ＳＤＳＰＡＧＥ表明该酶只有一种分子量约为６５ｋＤ的亚基,据此推测该酶应为同四聚体。酶催化磷酸二羟丙酮（ＤＨＡＰ）还原的最适ｐＨ值为７．５,催化Ｇ３Ｐ脱氢的最适ｐＨ值为１０。该酶对４个底物还原型辅酶Ⅰ（ＮＡＤＨ）,二磷酸吡啶核苷酸（ＤＨＡＰ）,辅酶Ⅰ（ＮＡＤ）,Ｇ３Ｐ的表观Ｋｍ值分别为６３μｍｏｌ／Ｌ,２７２μｍｏｌ／Ｌ,１．５３ｍｍｏｌ／Ｌ,６．５２ｍｍｏｌ／Ｌ。该酶在保存过程中易失活。ＮＡＤＨ能降低酶失活的速度,而ＮＡＤ则不然。低浓度ＮａＣｌ对酶略有保护作用,但高浓度ＮａＣｌ加快酶的失活,且浓度越高效应越明显。     

On the role of attention in binocular rivalry: electrophysiological evidence

During binocular rivalry visual consciousness fluctuates between two dissimilar monocular images. We investigated the role of attention in this phenomenon by comparing event-related potentials (ERPs) when binocular-rivalry stimuli were attended with when they were unattended. Stimuli were dichoptic, orthogonal gratings that yielded binocular rivalry and dioptic, identically oriented gratings that yielded binocular fusion. Events were all possible orthogonal changes in orientation of one or both gratings. We had two attention conditions: In the attend-to-grating condition, participants had to report changes in perceived orientation, focussing their attention on the gratings. In the attend-to-fixation condition participants had to report changes in a central fixation target, taking attention away from the gratings. We found, surprisingly, that attending to rival gratings yielded a smaller ERP component (the N1, from 160-210 ms) than attending to the fixation target. To explain this paradoxical effect of attention, we propose that rivalry occurs in the attend-to-fixation condition (we found an ERP signature of rivalry in the form of a sustained negativity from 210-300 ms) but that the mechanism processing the stimulus changes is more adapted in the attend-to-grating condition than in the attend-to-fixation condition. This is consistent with the theory that adaptation gives rise to changes of visual consciousness during binocular rivalry.     

Predicting Visual Consciousness Electrophysiologically from Intermittent Binocular Rivalry

Purpose

We sought brain activity that predicts visual consciousness.

Methods

We used electroencephalography (EEG) to measure brain activity to a 1000-ms display of sine-wave gratings, oriented vertically in one eye and horizontally in the other. This display yields binocular rivalry: irregular alternations in visual consciousness between the images viewed by the eyes. We replaced both gratings with 200 ms of darkness, the gap, before showing a second display of the same rival gratings for another 1000 ms. We followed this by a 1000-ms mask then a 2000-ms inter-trial interval (ITI). Eleven participants pressed keys after the second display in numerous trials to say whether the orientation of the visible grating changed from before to after the gap or not. Each participant also responded to numerous non-rivalry trials in which the gratings had identical orientations for the two eyes and for which the orientation of both either changed physically after the gap or did not.

Results

We found that greater activity from lateral occipital-parietal-temporal areas about 180 ms after initial onset of rival stimuli predicted a change in visual consciousness more than 1000 ms later, on re-presentation of the rival stimuli. We also found that less activity from parietal, central, and frontal electrodes about 400 ms after initial onset of rival stimuli predicted a change in visual consciousness about 800 ms later, on re-presentation of the rival stimuli. There was no such predictive activity when the change in visual consciousness occurred because the stimuli changed physically.

Conclusion

We found early EEG activity that predicted later visual consciousness. Predictive activity 180 ms after onset of the first display may reflect adaption of the neurons mediating visual consciousness in our displays. Predictive activity 400 ms after onset of the first display may reflect a less-reliable brain state mediating visual consciousness.     

Mismatch negativity of ERP in cross-modal attention

Event-related potentials were measured in 12 healthy youth subjects aged 19-22 using the paradigm "cross-modal and delayed response" which is able to improve unattended purity and to avoid the effect of task target on the deviant components of ERP. The experiment included two conditions: (i) Attend visual modality, ignore auditory modality; (ii) attend auditory modality, ignore visual modality. The stimuli under the two conditions were the same. The difference wave was obtained by subtracting ERPs of the standard stimuli from that of the deviant stim-uli. The present results showed that mismatch negativity (MMN), N2b and P3 components can be produced in the auditory and visual modalities under attention condition. However, only MMN was observed in the two modalities un-der inattention condition. Auditory and visual MMN have some features in common: their largest MMN wave peaks were distributed respectively over their primary sensory projection areas of the scalp under attention condition, but over front     

Characteristics of the parietal cortex activation in humans during different attention tasks

The cortical activation was estimated by the event-related potential (ERPs) methods during selection tasks of lateralized visual stimuli requiring different forms of attention: 1) form of stimuli, 2) stimuli position, 3) combined attention of form and position. The ERPs were recorded in 15 young healthy adults in 6 leads P3, P4, T3, T4, T5, T6, and endogenous ERPs components: CNV (contingent negative variation), N1, P3 and the complex [N1-P3]. Differences between the ERPs at "attended" and "non-attended" stimuli were considered as indices of selection attention of particular feature of visual stimuli. Such indices of form and position were revealed selectivity in parietal leads. The most eminent ERPs components, the pronounced activation gradient during increase of attention demands were revealed in parietal regions (vs. temporal ones). In our opinion, parietal cortex has a high priority in selection attention system.     

Effects on Automatic Attention Due to Exposure to Pictures of Emotional Faces while Performing Chinese Word Judgment Tasks

Two experiments were conducted to investigate the automatic processing of emotional facial expressions while performing low or high demand cognitive tasks under unattended conditions. In Experiment 1, 35 subjects performed low (judging the structure of Chinese words) and high (judging the tone of Chinese words) cognitive load tasks while exposed to unattended pictures of fearful, neutral, or happy faces. The results revealed that the reaction time was slower and the performance accuracy was higher while performing the low cognitive load task than while performing the high cognitive load task. Exposure to fearful faces resulted in significantly longer reaction times and lower accuracy than exposure to neutral faces on the low cognitive load task. In Experiment 2, 26 subjects performed the same word judgment tasks and their brain event-related potentials (ERPs) were measured for a period of 800 ms after the onset of the task stimulus. The amplitudes of the early component of ERP around 176 ms (P2) elicited by unattended fearful faces over frontal-central-parietal recording sites was significantly larger than those elicited by unattended neutral faces while performing the word structure judgment task. Together, the findings of the two experiments indicated that unattended fearful faces captured significantly more attention resources than unattended neutral faces on a low cognitive load task, but not on a high cognitive load task. It was concluded that fearful faces could automatically capture attention if residues of attention resources were available under the unattended condition.     

Fluid Intelligence and Automatic Neural Processes in Facial Expression Perception: An Event-Related Potential Study

The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8) and happy expressions were deviant stimuli (p = 0.2), and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8) and fearful expressions were deviant stimuli (p = 0.2). Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs) were obtained during the tasks. The visual mismatch negativity (vMMN) components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50–130 ms), the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320–450 ms), the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.     

Electrophysiological investigation of the texture discrimination mechanisms

In electrophysiological and psychophysical experiments, we investigated mechanisms of the visual system underlying local and global texture processing. Textures included rectangular matrixes composed of Gabor patches (sine wave grating windowed by a Gaussian envelope). Orientation of each grating varied from 0 to 165 degrees with the step of 15 degrees. Matrixes differed by the amount of Gabor patches with vertical or horizontal orientation. The observers' task was to discriminate the dominant orientation. The advantage of such stimuli involved a possibility to calculate global statistics of the textures, which we considered as the difference between whole amount of vertical and horizontal orientations in the stimulus irrespective of their location. The local statistics was calculated as relative amount of spatially organized nearby gratings (i. e. collinear contours). The subjects' accuracy was low in discriminating less organized textures and gradually improved with the amount of vertically of horizontally oriented Gabor patches, while the reaction time decreased. Visual evoked potentials (VEPs) recorded from occipital lobes revealed different dependencies of their components' magnitude on the amount of equally oriented gratings. Amplitude of the late positive component P3 with latency 400 ms directly depended on the texture discriminability, and N2 wave with latency 180 ms had an S-like dependence. Opposite to that, the magnitude of P2 wave with latency 260 ms was maximal in response to less organized textures and gradually decreased with the amount of equally oriented gratings. The dependencies received were compared with the textures' statistics. Data analysis allowed us to suppose that, in the conditions of our experimental paradigm, two mechanisms were involved in discrimination of the textures--the local and the global processing. We believe that by recording VEPs one can separately investigate activity of these two processes.     

Influence of very low doses of mediators on fungal laccase activity - nonlinearity beyond imagination

Background  

Compared to the waveform or spectrum analysis of event-related potentials (ERPs), time-frequency representation (TFR) has the advantage of revealing the ERPs time and frequency domain information simultaneously. As the human brain could be modeled as a complicated nonlinear system, it is interesting from the view of psychological knowledge to study the performance of the nonlinear and linear time-frequency representation methods for ERP research. In this study Hilbert-Huang transformation (HHT) and Morlet wavelet transformation (MWT) were performed on mismatch negativity (MMN) of children. Participants were 102 children aged 8–16 years. MMN was elicited in a passive oddball paradigm with duration deviants. The stimuli consisted of an uninterrupted sound including two alternating 100 ms tones (600 and 800 Hz) with infrequent 50 ms or 30 ms 600 Hz deviant tones. In theory larger deviant should elicit larger MMN. This theoretical expectation is used as a criterion to test two TFR methods in this study. For statistical analysis MMN support to absence ratio (SAR) could be utilized to qualify TFR of MMN.     

Assessment of spatial acuity at the fingertip with grating (JVP) domes: validity for use in an elderly population

JVP domes are of a set of small grating surfaces recently introduced for cutaneous spatial resolution measurement. The gratings are placed on the skin and subjects are required to identify the orientation of grooves and bars. The finest grating whose orientations are discriminated reliably (75% correct) provides an estimate of the spatial resolution limit in the tested area. In the present study, we sought to determine the capacity of elderly subjects to resolve such grating stimuli in order to obtain normative data for this population. Thirty-two elderly individuals in good health (range: 60-88 years) were assessed for their ability to perceive grating orientation at the tip of the dominant index finger. Testing proceeded from the widest grating dome (3 mm) to the next (e.g., 2 mm), until the performance level dropped below 75% correct discrimination. The grating orientation task proved to be very difficult for most subjects and only a minority (14/32) was able to provide reliable reports of grating orientation even with presentation of the widest dome available (3 mm). Accordingly, individual grating resolution thresholds were often considerably higher (> 2.5 mm, n = 26) than values previously reported in young adults for the fingertip region (approximately 1 mm). These results suggest that the current set of grating domes may not be adequate for spatial acuity measurement at the fingertip of older adults. New larger grating dimensions should be added to the set presently available to improve their sensitivity for an older population.     

Identification of Event-Related Potentials Elicited by Conceptual Mismatch Between Expectations and Self-chosen TV Images

When a voluntary action is followed by an unexpected stimulus, a late positive potential (LPP) with a posterior scalp distribution is elicited in a latency range of 500–700 ms. In the present study, we examined what type of mismatch between expectations and action outcomes was reflected by the LPP. Twelve student volunteers participated in a task simulating choice of TV programs. After choosing one of three options displayed as a cue stimulus, they viewed a second stimulus (still TV image). To manipulate the type of expectation, three kinds of cue conditions were used: thumbnail image condition (three small TV images), category label condition (three words), and no cue condition (three question marks). Over trials, the second stimulus either matched (p = .80) or mismatched (p = .20) the chosen option. As compared to matched TV images, mismatched TV images elicited a larger LPP (500–700 ms) in the thumbnail image and category label conditions. In addition, a larger centroparietal P3 (400–450 ms) was elicited to mismatched TV images in the thumbnail image condition alone. LPP reflects a conceptual mismatch between a category-based expectation and an ensuing action outcome, whereas P3 reflects a perceptual mismatch between an image-based expectation and an action outcome.