环境雌激素双酚A对成年小鼠学习记忆和突触结构的影响*

双酚A (bisphenol, BPA)是一种广泛存在的环境内分泌干扰物,它可与雌激素受体结合干扰内源性雌激素对中枢神经系统的调控作用。本研究通过将10周龄小鼠灌胃染毒BPA (0.4、4、40 mg/kg/day)3个月,研究长期BPA暴露对成年小鼠记忆行为和突触可塑性的影响。开场行为测试结果表明, BPA (0.4、4、40 mg/kg/day)增加雄性的站立次数和理毛频率, BPA (4 mg/kg/day)却显著减少雌鼠的站立次数。水迷宫和被动回避行为模型检测显示, BPA主要损伤雄鼠的空间学习记忆和被动回避记忆。通过制备海马CA1区超薄切片后,电镜观测发现, BPA (0.4、40 mg/kg/day)暴露降低雄鼠海马CA1区突触数密度,缩短雄鼠突触前活性带长度,减小雄鼠突触后致密体(PSD)厚度,增加雄鼠突触间隙宽度。进一步用Western blot方法检测突触前、后的标志性蛋白Synapsin I和PSD95以及兴奋性氨基酸NMDA受体NR1亚基和AMPA受体GluR1亚基蛋白的表达,发现BPA暴露致雄鼠Synapsin I、PSD95、NR1蛋白表达水平下调。而BPA对雌鼠的记忆行为、突触形态、突触蛋白和受体蛋白均没有明显作用。以上结果提示长期B PA暴露性别特异性地影响成年小鼠的活动性和探究行为,损伤雄鼠的学习记忆,这些作用可能通过下调突触蛋白和NMDA受体的表达而负性影响突触结构可塑性,最终影响雄鼠的学习记忆功能。     

客体工作记忆对注意的导向作用：抑制动机的影响

通过两个实验验证了客体工作记忆内容对注意的导向过程是灵活可控的; 与客体工作记忆内容匹配的刺激既可以捕获注意, 也可以被抑制。实验1通过操作匹配试验概率来诱发不同水平的抑制动机, 考察在客体工作记忆内容对注意的导向作用中抑制动机的影响。匹配试验中有分心物与客体工作记忆内容相同。控制试验中所有搜索项目均与客体工作记忆内容不同。实验2保持实际匹配试验概率恒定, 仅通过改变指导语来调节抑制动机水平, 以排除练习的干扰。两实验结果均表明, 当抑制动机水平较低时, 匹配分心物会捕获注意; 而当抑制动机水平足够高时, 匹配分心物会被抑制。并且, 抑制动机水平的高低还会影响认知控制的效应量和时程。     

胼胝体调节大脑两半球相互作用的机制

胼胝体是哺乳动物脑内最大的白质结构,不仅可以在大脑两半球间传递信息,也能调节半球间的相互作用,“抑制模型”和“兴奋模型”是当前解释胼胝体调节机制的主要模型.前者假设,胼胝体对半球间的信息传递起抑制作用,表现为优势半球的功能增强,非优势半球的活动抑制,因而可以提高半球加工的独立性和功能不对称性;后者则认为,胼胝体对半球间信息传递起促进作用,导致两半球同时性活动,并增强其功能连接性,因而可以降低半球的功能不对称性,有利于半球间的信息共享与功能整合.近期的研究显示,胼胝体并不是一个结构与功能的单一体,而是包含了在空间与时间上既分离又互动的多通道信息加工复合体.抑制与兴奋信息可以通过胼胝体的不同空间通道以不同的速度在半球间进行传递,并受到任务计算类型与复杂性的调节,因此,胼胝体的抑制与兴奋的协同可以调节两半球的动态相互作用.     

通货膨胀知觉的认知机制和影响因素

通货膨胀知觉是个体对通货膨胀的主观体验.通货膨胀知觉的认知机制主要体现在体验阶段和整合阶段.体验阶段主要涉及到个体对物价的感受性和记忆,整合阶段主要涉及到个体利用可得性启发式以及锚定和调整启发式完成对通货膨胀的最终估计.通货膨胀知觉的影响因素主要包括通货膨胀预期、框架效应、对价格公平性的认知、社会放大效应以及货币改革等.未来可以从通货膨胀知觉的信息加工方式、认知神经机制、跨文化研究以及具有较高生态效度的测量指标等方面进一步探讨.     

诗歌与禅宗的会通观

作为一种抵达艺术与人生至境的独特修持方法，诗与禅秉持“悟”、“妙悟”而抵达般若妙境。禅宗不藉文字、否弃概念，通过对思维定势的消解而超越对立，以情尘意垢的遣除而洞见自性本心，其进入诗学领域，对诗歌发生的艺术思维与个体审美心理体验产生了深刻的影响，它自见本性、直指本心的超验意识，与文艺创造活动圆融、会通。     

张景岳医易学思想新论

张景岳医易学思想中的两个重要问题,一是关于外易与内易及其相互之间的关系;二是通过对神与机、鬼与神、升与降等范畴的论述,提出了一个医易学的心理平衡系统.这两点都是发前人所未发,值得进行深入探讨.     

由能知而自知--意识研究的若干问题

笛卡尔的“心身二元论”开启了近代以来的心智哲学,他提出的心身问题的两个方面,即心身区别和心身因果相互作用,似乎构成了迄今为止笛卡尔哲学的辩护者和反对者的共同领域。笛卡尔给他的后继者们留下两种可能性:或者是消解二元对立;或者是修订相互作用论,其后世的心智哲学基本上是沿着这两条道路前进的。而当代心智哲学对意识的分析也具体体现了现代哲学对于传统的作为认识主体的“心灵实体”的解构。一　意识的难解之谜关于意识的研究所面对的是两种不同的对象:一种是从主观的角度用内省方法得到的自己头脑中的“内部现象”,我们据此承认意…     

Tests of statistical hypotheses in the case of unequal or disproportionate numbers of observations in the subclasses

General solutions of the analysis of variance in the case of unequal numbers of observations in the subclasses are presented. If we havek criteria for the classification, there will bek! solutions in making a complete analysis and 2^k–1 answers, bearing different meanings, for the sum of squares between subclasses of each criterion. The sum of squares for the interaction of any order, however, will be identical in different solutions of same problem.     

Factorial design and covariance in the study of individual educational development

This is the report of the application of the principles of factorial design to an investigation of individual educational development. The specific type of factorial design formulated was a 2 × 3 × 3 × 3 arrangement, that is, the effect of sex, grade location, scholastic standing, and individual order, singly and in all possible combinations was studied in relation to educational development as measured by theIowa Tests of Educational Development. An application of the covariance method was introduced which resulted in increased precision of this type of experimental design by significantly reducing experimental error. The two concomitant measures used to increase the sensitiveness of the experiment were initial status of individual development and mental age. Without these statistical controls all main effects and two first-order interactions would have been accepted as significant. With their use only sex (doubtful), scholastic standing, and individual order demonstrated significant effects. The chief beauty of the analysis of variance and covariance as an integral part of a self-contained experiment is demonstrated in the complete single analysis of the data. The statistical utilization of the experimental results has also been developed for purposes of estimation and prediction. The mathematical statistician is being continuously required to develop and analyze experimental designs of increasing complexity since the introduction of the analysis of variance and covariance. The mathematical formulation and solution of the problem of this investigation is carried out. The methods illustrated and explained in this study, and modifications and extensions of them are capable of very wide application. The general principles can be used to various degrees and in a number of ways.For the research grant to finance this study, grateful acknowledgment is given to the Graduate School, the University of Minnesota.