Galpha(i2) inhibition of adenylate cyclase regulates presynaptic activity and unmasks cGMP-dependent long-term depression at Schaffer collateral-CA1 hippocampal synapses

Cyclic AMP signaling plays a central role in regulating activity at a number of synapses in the brain. We showed previously that pairing activation of receptors that inhibit adenylate cyclase (AC) and reduce the concentration of cyclic AMP, with elevation of the concentration of cyclic GMP is sufficient to elicit a presynaptically expressed form of LTD at Schaffer collateral-CA1 synapses in the hippocampus. To directly test the role of AC inhibition and G-protein signaling in LTD at these synapses, we utilized transgenic mice that express a mutant, constitutively active inhibitory G protein, Galpha(i2), in principal neurons of the forebrain. Transgene expression of Galpha(i2) markedly enhanced LTD and impaired late-phase LTP at Schaffer collateral synapses, with no associated differences in input/output relations, paired-pulse facilitation, or NMDA receptor-gated conductances. When paired with application of a type V phosphodiesterase inhibitor to elevate the concentration of intracellular cyclic GMP, constitutively active Galpha(i2) expression converted the transient depression normally caused by this treatment to an LTD that persisted after the drug was washed out. Moreover, this effect could be mimicked in control slices by pairing type V phosphodiesterase inhibitor application with application of a PKA inhibitor. Electrophysiological recordings of spontaneous excitatory postsynaptic currents and two-photon visualization of vesicular release using FM1-43 revealed that constitutively active Galpha(i2) tonically reduced basal release probability from the rapidly recycling vesicle pool of Schaffer collateral terminals. Our findings support the hypothesis that inhibitory G-protein signaling acts presynaptically to regulate release, and, when paired with elevations in the concentration of cyclic GMP, converts a transient cyclic GMP-induced depression into a long-lasting decrease in release.     

注意缺陷多动障碍儿童在不同加工阶段的干扰控制

采用刺激－刺激和刺激－反应相容性任务范式,将信息加工在知觉和反应阶段的冲突效应分离开来,考察注意缺陷多动障碍（Attention Deficit Hyperactivity Disorder,简称ADHD）儿童在知觉和反应阶段冲突控制的模式和时间轨迹。结果发现,在反应阶段,ADHD儿童的干扰控制能力明显弱于正常对照组儿童,混合型ADHD儿童的能力更弱于注意缺陷型ADHD儿童;在知觉阶段,ADHD儿童没有明显的干扰抑制缺损,两组ADHD儿童（注意缺陷型和混合型）的表现模式相似;儿童抑制冲突干扰所遵循的时间轨迹在知觉和反应阶段有所不同：与知觉阶段相比,反应阶段需要更长的时间才能抑制冲突干扰。但ADHD儿童和正常儿童之间的表现模式相似     

个体认知方式与材料复杂性对视空间工作记忆的影响

采用计算机呈现的Corsi积木点击任务,探讨了不同认知方式个体对材料的路径、结构和数量复杂性不同的视空间工作记忆的广度。研究结果表明：（1）场独立性认知方式是影响视空间工作记忆广度的一个重要的个别差异变量,在路径复杂或呈现的材料结构随机的条件下,场独立者的视空间工作记忆广度明显高于场依存者;（2）材料呈现的路径、数量是影响视空间记忆广度的重要因素,在路径简单或数量少的情况下被试的视空间记忆广度要明显得高     

内疚和羞耻的关系——来自反事实思维的验证

运用情境模拟法从反事实思维的角度探讨内疚与羞耻的关系.并比较了大学生和青少年罪犯反事实思维与内疚和羞耻关系方面的特点.结果表明:(1)研究结果部分支持"内疚事件和羞耻事件"假设,但不支持Lewis提出的"自我和行为"假设,甚至与该假设相反;(2)大学生和青少年罪犯反事实思维与内疚和羞耻的关系具有某些方面的一致性.但也存在着很大的差异.大学生自我导向的反事实思维与内疚感有更为密切的联系,而青少年罪犯行为导向的反事实思维与羞耻感有更为密切的联系.     

双重攻击模型的实证研究

本研究通过两个实验对双重攻击模型进行了验证.实验一借助实验性分离的逻辑,发现性别对内隐攻击性和外显攻击性存在不同影响,初步证明内隐攻击性和外显攻击性的分离论.实验二通过实证性因素分析,证明双重攻击模型具有较高的拟合参数.本研究证明内隐攻击性和外显攻击性分属两个不同的结构,构成双重攻击模型.     

周代战车驾马数探析

两周时期是车战盛行的时代,从上古文献记载来看,几乎是整齐划一的驷马驾车格局。然而仔细梳理两周时期的考古发现可见,文献记载与考古发现不相吻合,而地下出土文献如金文、简帛文献可以与考古实物相互印证,即以二马之驾居多。这说明,战车驾二是当时的驾马常制,传世文献多文学作品,有溢美之处。     

闪光滞后效应的机制：时间错觉与空间错觉

闪光滞后效应（flash—lag effect,FLE）是指在与某运动物体相同的位置上呈现的闪光（flash）知觉上滞后于该运动物体的视错觉。本文简要介绍了有关闪光滞后效应机制的理论模型。笔者认为,目前各种理论的争议可归结为时间错觉假说与空间错觉假说之争,并在此基础上就今后进一步研究的方向提出了建议。     

论新中国伦理学的发展及其前瞻

建国以来,中国的伦理学在马克思主叉理论的指引下,传承中国优秀传统伦理,吸收圆外先进伦理理念,其学科经历了形成、发展、繁荣的过程.新中国伦理学理论建设丰富了哲学学科的人文内容和现实关怀,推动了哲学学科的发展,同时在实践层面上,为推动社会主义市场经济健康发展,培育良好社会风尚,塑造新时代的道德人格,做出了巨大贡献.     

Existential function of babies: Babies as a buffer of death-related anxiety

The present study examined babies as death anxiety buffers with Chinese participants in three experiments. In Experiment 1, death-related thoughts increased college-aged participants' interest in human babies. In Experiment 2, images of newborn animals reduced the number of death-related thoughts recorded by college-aged participants. In Experiment 3, female factory workers who read news articles describing deaths of babies had pessimistic estimations of their own life expectancies. An explanation of these results is provided within a terror management theory framework, with a primary focus on how babies reinforce cultural worldviews and enhance self-esteem via the notion of symbolic immortality. Thus, the anxiety-buffering function of baby is subsumed under cultural worldviews validation and self-esteem enhancement.     

错误记忆的产生是否依赖对词表的有意加工：无意识激活的证据

使用DRM范式考察了错误记忆产生过程中无意识激活的存在与否。通过操纵实验任务和呈现方式,导致被试对学习词表的无意加工和不同水平的有意加工。结果发现,无意加工时所产生的对关键诱饵的无意识激活足以导致错误记忆效应,说明对词表的有意加工并非错误记忆产生所必需。随着对词表有意加工水平的提高,多次无意识激活的累积可导致增强的错误记忆效应,且表现出与真实记忆的共变,而阻断连续激活累积的因素可有效降低错误记忆