海马CA_3区习得性LTP的进一步探讨

分辨学习中大鼠ＰＰ－ＣＡ_３突触效应有习得性ＬＴＰ产生,进一步观察到ＭＦ－ＣＡ_３及Ｃｏｍｍ－ＣＡ_３也同步地产生习得性ＬＴＰ,表明几种输入突触都产生习得性ＬＴＰ,而ＭＦ－ＣＡ_３突触效应增强的程度则较Ｃｏｍｍ－ＣＡ_３的为大（Ｐ＜０．０１）。海马ＣＡ_３注入印防己毒素能易化ＰＰ－ＣＡ_３突触习得性ＬＴＰ的产生,工作发现一侧海马ＣＡ_３注印防己毒素,易化对侧ＭＦ－ＣＡ_３突触习得性ＬＴＰ的产生,表明两侧海马ＣＡ_３区在其习得性ＬＴＰ的形成上是相互协同的。     

大学生皮肤电反应、MMPI及其关系的初步研究

应用日产Ｓａｎ－ｅｉｌＡ９７Ａ型脑电图机及ＭＭＰＩ（中国版本）对２６名大学生进行了皮肤电反应记录及人格特征的测查。结果表明：（１）普通大学生中皮电基础水平个体差异十分明显。（２）皮电平均每分钟自发波动次数与ＭＭＰＩ中的Ｄ、Ｓｉ、Ｍａｓ、Ｃｎ呈显著正相关,与Ｌ、Ｋ呈显著负相关。皮电平均每分钟自发波动幅度与Ｆ、Ｄ、Ｍａｓ呈显著正相关;与Ｌ呈显著负相关。（３）皮电基础水平高组与低组在Ｌ、Ｓｉ、Ｍａｓ之Ｔ分上的差异达显著水平。（４）习惯化倾向差组与优组在Ｋ、Ｓｔ、ＭａｓＴ分的差异有显著意义,差组与中组在Ｓｉ、ＣｎＴ分上有显著性差异。（５）习惯化倾向差组皮电基础水平较高;优组皮电基础水平较低,两组差异达显著水平。     

LTP诱导期向维持或转化过程中的突触形态学特征

该研究探讨了视皮层ＬＴＰ由诱导期向维持期转化过程的突触形态学特征。实验选用１８－３０天龄的健康ＳＤ大鼠,分实验组、空白对照组及实验对照组进行电镜观测和图象分析。结果发现,在常规ＬＴＰ实验程序中强直刺激后有ＬＴＰ产生并记录８０分钟的实验组脑片标片,局部有界面曲率大于２的较大Ｕ型突触形成,这种突触多有两个以上活性区。图象分析结果显示,实验组与对照组相比较,突触的界面曲率明显增大（Ｐ〈０．０５）,活性区     

与立体视觉相关的视诱发电位研究

在微机上编制能产生动态随机点立体图（ＤＲＤＳ）,亮暗类棋盘格和随机点背景三种图形刺激的软件．记录了３４例正常人在这三种刺激下的ＶＢＰ．其结果为：（１）ＤＲＤＳ刺激下的ＶＥＰＮ１波潜伏期为２６５±２５ｍｓ,基波能量占总交流能量的６３．２±１８．９％．（２）亮暗类棋盘格刺激下的ＶＥＰＮ１波的潜伏期为１９０±２２ｍｓ,基波能量占总交流能量的３９．２±１９．６％．（３）随机点背景刺激下的ＶＥＰ波则为一些杂乱的小波．结果提示：动态ＲＤＳ刺激下的ＶＥＰ除在潜伏期方面具有特异性外,并在谐波的能量分布上也具有特异性,且客观性更强．根据这些特征有助于对立体视觉功能进行客观性评价．     

医疗统计微机管理系统的应用

医疗统计微机管理系统的应用大连市友谊医院（１１６０１１）徐晓慧大连医科大学（１１６０２７）张英强一、系统运行环境硬件环境：４８６、５８６微机，宽行打印机、１６００ＫＢ（２台）软件环境：ＭＳ－ＤＯＳ３３１，ＵＰＤＯＳ３２语言使于单位间的横向及纵向比...     

知难而进的斗士──桑德斯

作为ＡＭＤ（超微）公司的创始者、美国半导体协会的主席，桑德斯（Ｗ．Ｊ．Ｓａｎｄｅｒｓ）是美国信息产业界极富个性的一个领袖。ＡＭＤ正是在桑德斯的领导之下，与英特尔（Ｉｎｔｅｌ）及国家半导体公司 （Ｎａｔｉｌｎａ Ｓｅｍｉｃｏｎ－ｄｕｃｔｏｒ）在激烈的市场竞争中相抗衡，并拥有一席之地的。ＡＭＤ公司经营风格中渗透着桑德斯的个性，说其是ＡＭＤ的旗帜，也并不为过。 和英特尔公司的诺伊斯（Ｒｏｂｅｒ’ｔ Ｎｏｙｃｅ）、格鲁夫（Ａｎｄｎ Ｇｒｏｖｅ）、摩尔（Ｇｏｄｏｎ Ｍｏｏｒｓ）一样，桑德斯也曾经为硅谷中具有传奇…     

团体决策支持系统（GDSS）与心理学

团体决策支持系统（ＧＤＳＳ）与心理学王辉,张侃中国科学院心理研究所（北京１０００１２）［摘要］＊ＧＤＳＳ是以完成联合决策活动为目的的计算机支持系统,自８０年代出现以来,已成为ＤＳＳ的一个主要发展方向。由于ＧＤＳＳ最终是给人用的,尤其是为人的决策这一复...     

因特网医学文献检索中的方法问题：谈医学文献数据库PUBMED的应用

医学文献联机检索数据库（ＭＥＤＬＩＮＥ）是美国国立医学图书馆（ＮＬＭ）建立的世界上最著名的生物医学数据库之一。ＮＬＭ同时在因特网上建立了免费的、能够提供ＭＥＤＬＩＮＥ检索的公众医学数据库（ＰＵＢＭＥＤ）［１］。两年来,作者利用因特网进行医学文献检索对本人的科研工作和知识提高帮助很大。在应用过程中作者也进行了一些哲学思考,在此提出来与大家探讨。１　网上检索促进了搜集科技情报方法的进步文献资料是人类智慧的共同结晶,是人们积累知识、增长学问的重要媒介,也是科研人员发现、形成课题和指定规划的依据之一。查…     

少年儿童音乐静坐训练对听觉失匹配负波与P300的影响及其意义

在静坐前后,测定２３例经半年音乐静坐训练（实验组）和未经训练（对照组）的１３岁少年的听觉失匹配负波（ＭＭＮ）和Ｐ３００。结果发现,实验组的ＭＭＮ波幅和面积均比对照组显著增高．并且ＭＭＮ变化发生在组间而不是一次静坐前后,但Ｐ３００没有显著性变化。提示实验组的ＭＭＮ效应是长期的而不是短时的;在本实验条件下评定正常人脑的某些认知功能．ＭＭＮ是比Ｐ３００更为灵敏的电生理学指标。     

两种竞赛状态焦虑调控方法的比较研究

本研究以上海市射击队部分射击运动员为被试,对生物反馈放松训练法（ＢＦＢ—Ｒ）和认知情感应激调控法（ＳＭＴ）两种竞赛焦虑调控法进行了比较研究。结果表明：（１）在实验室条件下,ＳＭＴ和ＢＦＢ—Ｒ都能帮助射击运动员提高包括放松和想象能力在内的心理控制能力;（２）实验组被试在比赛中表现出了较低的身体状态焦虑水平,较高的状态自信心水平;（３）ＳＭＴ组被试的比赛成绩优于ＢＦＢ—Ｒ组被试。     

同一学习中海马不同区的习得性长时程突触增强的形成

本研究探查大鼠分辨学习中海马齿状回(DG)和CA_3区突触效应的变化及其相互关系,以探讨同一学习中海马不同区突触可塑性变化的特点及其相互关系,进一步论证习得性长时程增强(LTP)是学习和记忆的神经基础。发现:(1)穿通纤维的单个刺激可在DG和CA_3同时记录到潜伏期、峰值和波形各异的群体峰电位(PS);在一定范围内PS随刺激强度的增加而增大,但DG的PS增大程度比CA_3的小;据此,检测刺激的强度应选在该范围内。(2)随着行为训练,DG和CA_3区的突触传递同时产生LTP,两者LTP的发展是显著正相关关系(P<0.01),PS峰值同时达到最高水平,且先于分辨反应达学会标准,首次表明在同一学习中大鼠海马的DG和CA_3的习得性LTP是同时产生的。本研究还表明,在慢性实验下同时记录和分析行为学习中海马两个区突触效应的变化及其相互关系是可能的,这给从神经环路角度研究学习和记忆的突触机制提供了有用的模型。     

去甲肾上腺素对习得性长时程突触增强的影响

在大鼠条件性饮水反应的建立和巩固过程中,在每天训练之前,通过预先与记录电极一起埋植在海马齿状回的注药管,微量注射去甲肾上腺素(NE),观察其对海马齿状回的习得性长时程突触增强的影响。结果表明:NE能增强突触效应;训练作业前注NE易化了习得性长时程突触增强的形成,但对其巩固无影响;同时相应地易化了动物条件反应的建立。提示NE参与海马齿状回的习得性长时程增强的形成。本文对其可能的作用机制进行了讨论。     

Extinction memory improvement by the metabolic enhancer methylene blue

We investigated whether postextinction administration of methylene blue (MB) could enhance retention of an extinguished conditioned response. MB is a redox compound that at low doses elevates cytochrome oxidase activity, thereby improving brain energy production. Saline or MB (4 mg/kg intraperitoneally) were administered to rats for 5 d following extinction training of tone-footshock conditioning. Postextinction freezing was lower in rats receiving MB compared with saline, suggesting that MB improved retention of the extinction memory. The MB effect was specific to tone-evoked freezing because there were no differences in pretone freezing. Control subjects similarly injected with MB showed no evidence of nonspecific effects on measures of motor activity and fearfulness. MB-treated rats exhibited both greater retention of extinction and greater overall brain metabolic activity. Rats with higher retention of extinction also showed a relative increase in cytochrome oxidase activity in prefrontal cortical regions, especially anterior infralimbic cortex, dorsal and medial frontal cortex, and lateral orbital cortex. These regional metabolic increases were also correlated to the behavioral freezing index used to assess retention of extinction. It was concluded that MB administered postextinction could enhance retention of extinction memory through an increase in brain cytochrome oxidase activity.     

Differential effect of TEA on long-term synaptic modification in hippocampal CA1 and dentate gyrus in vitro.

The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni2+ (50 microM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni2+ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 microM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni2+. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni2+. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus.     

The expression of c-Fos and colocalisation of c-Fos and glucocorticoid receptors in brain structures of low and high anxiety rats subjected to extinction trials and re-learning of a conditioned fear response

We designed an animal model to examine the mechanisms of differences in individual responses to aversive stimuli. We used the rat freezing response in the context fear test as a discriminating variable: low responders (LR) were defined as rats with a duration of freezing response one standard error or more below the mean value, and high responders (HR) were defined as rats with a duration of freezing response one standard error or more above the mean value. We sought to determine the colocalisation of c-Fos and glucocorticoid receptors-immunoreactivity (GR-ir) in HR and LR rats subjected to conditioned fear training, two extinction sessions and re-learning of a conditioned fear. We found that HR animals showed a marked decrease in conditioned fear in the course of two extinction sessions (16 days) in comparison with the control and LR groups. The LR group exhibited higher activity in the cortical M2 and prelimbic areas (c-Fos) and had an increased number of cells co-expressing c-Fos and GR-ir in the M2 and medial orbital cortex after re-learning a contextual fear. HR rats showed increased expression of c-Fos, GR-ir and c-Fos/GR-ir colocalised neurons in the basolateral amygdala and enhanced c-Fos and GR-ir in the dentate gyrus (DG) in comparison with LR animals. Our data indicate that recovery of a context-related behaviour upon re-learning of contextual fear is accompanied in HR animals by a selective increase in c-Fos expression and GRs-ir in the DG area of the hippocampus.     

Differential Effect of TEA on Long-Term Synaptic Modification in Hippocampal CA1 and Dentate Gyrus in vitro

The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni²⁺ (50 μM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni²⁺ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 μM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni²⁺. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni²⁺. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus.     

Assessment of retention capacities in old rats

Young (3-6 month) and old (24-27 month) barrier reared Wistar rats were tested for their ability to retain an inhibitory (passive) avoidance, acquired immobility, and a conditioned taste aversion response as a function of time. Old rats exhibited accelerated forgetting of both the inhibitory avoidance and acquired immobility response in comparison to young rats. In contrast, old rats displayed good retention of the conditioned taste aversion response at all time intervals tested. It appears that the dynamic aspects of retention are altered in aged rats depending on the task, and in some instances may be expressed as accelerated forgetting.     

Effects of multisensory environmental stimulation on contextual conditioning in the developing rat

The effect of increased exposure to multisensory stimulation during development on conditioned freezing to contextual cues in preweanling Sprague-Dawley rats was examined. Rats given increased environmental stimulation exhibited long-term contextual conditioning at a younger age than rats that did not receive such stimulation when there was either low or moderate levels of conditioning (Experiments 1 and 2). These differences in contextual conditioning were not a result of the stimulated rats reacting differently to shock (Experiment 4) or merely freezing more than the nonstimulated rats in all situations (Experiment 3). The role of the glucocorticoid system in the enhanced contextual learning of stimulated preweanling rats and the advantages of the contextual conditioning procedure for studying the effects of environmental stimulation are discussed.     

Classical conditioning of hippocampal theta patterns in the rat.

Electrical stimulation (88 HZ) of the lateral hypothalamus elicited a sustained theta response at hippocampal recording sites of rats immobilized with succinylcholine. By pairing this unconditioned stimulus with a 10-sec presentation of a light, conditioned theta responses were demonstrated in as few as 40 trials. Spectral analysis of hippocampal bioelectric patterns during acquisition, extinction, and reconditioning indicated that the earliest change as a result of conditioning is a loss of power in EEG frequency below 8 HZ, followed by the development of a peak at 8 HZ with further conditioning. Extinction was associated with an increase in power in the frequencies below 8 HZ. When the conditioned rats were tested in the absence of the neuromuscular blocking agent, the conditioned stimulus elicited a theta response that was associated with slow motor activity on 70% of the trials.