斑马鱼在生命科学研究中的应用

利用模式生物进行研究是推动生命科学发展的主要手段之一.斑马鱼已成为继小鼠之后的又一个重要的模式脊椎动物.本文将重点介绍斑马鱼在学习记忆和疾病研究领域中的应用,以及我国推动斑马鱼相关研究的策略.     

国际权威学术期刊Science发表郭爱克院士、郭建增博士果蝇学习与记忆的最新成果

2005年7月8日,国际权威学术期刊Science发表了中科院上海生命科学研究院神经科学研究所、中科院生物物理研究所郭爱克院士和中国科学院上海生命科学研究院神经科学研究所郭建增博士研究的果蝇学习与记忆的最新成果：果蝇跨模态学习的相互作用。这是由郭爱克领导的学习与记忆实验室再度以全本土研究工作在Science上发表论文,文章向人们讲述了在一定的时间一空间条件下,果蝇在视觉和嗅觉不同模态之间的学习与记忆的协同双赢和相互传递的科学发现。全部实验和科学发现是以果蝇为模式动物,在精巧的飞行模拟器上完成的,历时三年半,实验严格证明了视／嗅双模态之间的“协同共赢”、“互利互惠”和“相互传递”都对双模态信息输入的时间一致性有严格要求的论断。     

蛋白激酶与神经系统功能调控

翻译后的磷酸化修饰是蛋白质结构和功能的重要调节方式。催化蛋白质磷酸化过程的蛋白激酶广泛参与神经发育、感觉、学习记忆、情绪与认知等生理过程及神经退行性疾病、慢性疼痛及精神疾病等病理生理过程,是生命科学领域的研究热点。现将举例说明蛋白激酶在神经系统内的重要作用,并介绍以蛋白激酶为靶点的药物开发现况。     

高中生物学教学应重视科学概念的生成

高中生物学有许多重要的科学概念,是学生学习生命科学必须掌握的基础知识,教学中应高度重视概念的生成过程而不是单纯地记忆概念。运用丰富的生物学事实、生命科学史及探究等方法能有效地帮助学生生成概念,并在生活实践中利用建立起的科学概念解决现实问题,进一步加深对概念的理解。     

开展探究性实验 培养学生生命科学素养

<正>生命科学素养是指学生学习生命科学知识过程中,所形成的适应社会发展和人类自身完善所需要的生命科学方面的基本品质和能力。生命科学素养包括生命科学知识与技能、生命科学知识的形成过程与研究方法、科学的情感态度与价值观等。但学生的生命     

激发学生学习医学微生物学兴趣的“六个结合”教学法

医学微生物学一门与临床、社会、历史和生命科学发展前沿紧密联系的学科。“六个结合”教学法,就是基于这种联系、结合这些因素去讲授医学微生物学的教学法,是一种“源自生活”的教学法;“六个结合”教学法,可激发学生的学习兴趣,加深他们对教材知识的理解和记忆,并能将所学知识活学活用。     

若干有关学习和记忆神经机制问题的讨论

若干有关学习和记忆神经机制问题的讨论梅镇彤（中国科学院上海生理研究所,上海２０００３１）目录一、学习和记忆的分类问题二、突触可塑性与学习记忆三、运动学习记忆的神经基础四、长时记忆分子生物学研究的新进展五、结束语学习和记忆是脑的重要功能,关于学习和记忆...     

基于课程标准的初中生命科学实验学习的评价研究

实验教学是生命科学学科教学的重要内容,是生命科学学科教学中的一大特色。为提高实验教学的有效性,学习评价这一反馈环节尤为重要。分析了当前初中生命科学实验学习评价中存在的问题,为探寻实验评价的有效方式,提高实验教学的实效性,提出在学科课程标准的基础上,自主设计实验评价表,并在实际教学中探索、实践与反思。希望借此引起教师的共鸣,共同探讨并完善该评价方式,促进实验教学,推动学生发展。     

大小鼠学习记忆行为实验方法分类概述

学习记忆发生机制复杂,表现形式多样,产生过程涉及到信号的识别和辩认、信息的获得、巩固、再现和再巩固等多个环节;记忆的信息又包括图象记忆、声音记忆、嗅觉记忆、空间位置记忆等;根据信息保存时间的长短,分为短时记忆与长时记忆。行为学实验是评价学习记忆的主要手段。迄今为止,科学家建立了多种大、小鼠行为实验方法用于学习记忆的评价。本文首次对学习记忆行为学实验方法进行了分类和概述,针对不同类型列举不同的评价方法,为基于行为实验的学习记忆研究、相关的产品研发提供参考。     

科学创新与创新的科学

创新是推动生物科技产业发展的动力,而对于创新这个过程本身的研究也是目前生命科学,特别是神经科学研究的热点之一。创新和记忆都来自于联想,或者说来自于把不同的事物联系起来;对于记忆来说,是把新知识和已知的知识联系起来,而创新则是把所接收到的各种信息重新组合。形成前所未有的创意。     

Recollection-Based Retrieval Is Influenced by Contextual Variation at Encoding but Not at Retrieval

In this article, we investigated the effects of variations at encoding and retrieval on recollection. We argue that recollection is more likely to be affected by the processing that information undergoes at encoding than at retrieval. To date, manipulations shown to affect recollection were typically carried out at encoding. Therefore, an open question is whether these same manipulations would also affect recollection when carried out at retrieval, or whether there is an inherent connection between their effects on recollection and the encoding stage. We therefore manipulated, at either encoding or retrieval, fluency of processing (Experiment 1)—typically found not to affect recollection—and the amount of attentional resources available for processing (Experiments 2 and 3)—typically reported to affect recollection. We found that regardless of the type of manipulation, recollection was affected more by manipulations carried out at encoding and was essentially unaffected when these manipulations were carried out at retrieval. These findings suggest an inherent dependency between recollection-based retrieval and the encoding stage. It seems that because recollection is a contextual-based retrieval process, it is determined by the processing information undergoes at encoding—at the time when context is bound with the items—but not at retrieval—when context is only recovered.     

Sleep-related hippocampo-cortical interplay during emotional memory recollection

Emotional events are usually better remembered than neutral ones. This effect is mediated in part by a modulation of the hippocampus by the amygdala. Sleep plays a role in the consolidation of declarative memory. We examined the impact of sleep and lack of sleep on the consolidation of emotional (negative and positive) memories at the macroscopic systems level. Using functional MRI (fMRI), we compared the neural correlates of successful recollection by humans of emotional and neutral stimuli, 72 h after encoding, with or without total sleep deprivation during the first post-encoding night. In contrast to recollection of neutral and positive stimuli, which was deteriorated by sleep deprivation, similar recollection levels were achieved for negative stimuli in both groups. Successful recollection of emotional stimuli elicited larger responses in the hippocampus and various cortical areas, including the medial prefrontal cortex, in the sleep group than in the sleep deprived group. This effect was consistent across subjects for negative items but depended linearly on individual memory performance for positive items. In addition, the hippocampus and medial prefrontal cortex were functionally more connected during recollection of either negative or positive than neutral items, and more so in sleeping than in sleep-deprived subjects. In the sleep-deprived group, recollection of negative items elicited larger responses in the amygdala and an occipital area than in the sleep group. In contrast, no such difference in brain responses between groups was associated with recollection of positive stimuli. The results suggest that the emotional significance of memories influences their sleep-dependent systems-level consolidation. The recruitment of hippocampo-neocortical networks during recollection is enhanced after sleep and is hindered by sleep deprivation. After sleep deprivation, recollection of negative, potentially dangerous, memories recruits an alternate amygdalo-cortical network, which would keep track of emotional information despite sleep deprivation.     

Recognition memory and the medial temporal lobe: a new perspective

Recognition memory is widely viewed as consisting of two components, recollection and familiarity, which have been proposed to be dependent on the hippocampus and the adjacent perirhinal cortex, respectively. Here, we propose an alternative perspective: we suggest that the methods traditionally used to separate recollection from familiarity instead separate strong memories from weak memories. A review of work with humans, monkeys and rodents finds evidence for familiarity signals (as well as recollection signals) in the hippocampus and recollection signals (as well as familiarity signals) in the perirhinal cortex. We also indicate ways in which the functions of the medial temporal lobe structures are different, and suggest that these structures work together in a cooperative and complementary way.     

"What-Where-Which" Episodic Retrieval Requires Conscious Recollection and Is Promoted by Semantic Knowledge

Episodic memory is defined as the conscious retrieval of specific past events. Whether accurate episodic retrieval requires a recollective experience or if a feeling of knowing is sufficient remains unresolved. We recently devised an ecological approach to investigate the controlled cued-retrieval of episodes composed of unnamable odors (What) located spatially (Where) within a visual context (Which context). By combining the Remember/Know procedure with our laboratory-ecological approach in an original way, the present study demonstrated that the accurate odor-evoked retrieval of complex and multimodal episodes overwhelmingly required conscious recollection. A feeling of knowing, even when associated with a high level of confidence, was not sufficient to generate accurate episodic retrieval. Interestingly, we demonstrated that the recollection of accurate episodic memories was promoted by odor retrieval-cue familiarity and describability. In conclusion, our study suggested that semantic knowledge about retrieval-cues increased the recollection which is the state of awareness required for the accurate retrieval of complex episodic memories.     

A hippocampal marker of recollection memory ability among healthy young adults: contributions of posterior and anterior segments

The hippocampus is known to support recollection memory, but the relation between its structure and recollection in healthy adults has not been established. Here we show that the hippocampus (including subiculum, DG, and CA1-CA4), when separated into posterior and anterior segments, can reliably predict recollection in healthy young adults. Better memory was associated with larger posterior and smaller anterior segments, as evaluated relative to the uncal apex. Overall hippocampal volume, however, did not predict memory. This pattern was confirmed in four separate data sets from different studies and laboratories. The relationship between the posterior hippocampus and memory was mediated by the structure's functional connectivity with a neocortical network identified during a postencoding resting-state scan. The relationship was also weakest in an experiment involving no appreciable study-test interval. These findings suggest that enhanced posterior-hippocampal postencoding processes may account for the memory benefit associated with larger posterior hippocampi.     

Recollection ability of three-dimensional correlation matrix associative memory

This paper presents the approximate expression of the recollection probability of a three-dimensional correlation matrix autoassociative memory, in which each memorized pattern consists of binary (+1 or-1) elements, and discusses the recollection ability in comparison with that of the conventional two-dimensional correlation matrix associative memory. An associative memory using the correlation properties between memorized patterns desires the condition that the memorized patterns are mutually orthogonal or approximately orthogonal. The three-dimensional correlation matrix associative memory that inscribes the third order correlation of a memorized pattern heightens the recollection ability even though the above condition is not satisfied.     

The cognitive neuroscience of memory: perspectives from neuroimaging research.

Cognitive neuroscience approaches to memory attempt to elucidate the brain processes and systems that are involved in different forms of memory and learning. This paper examines recent research from brain-damaged patients and neuroimaging studies that bears on the distinction between explicit and implicit forms of memory. Explicit memory refers to conscious recollection of previous experiences, whereas implicit memory refers to the non-conscious effects of past experiences on subsequent performance and behaviour. Converging evidence suggests that an implicit form of memory known as priming is associated with changes in posterior cortical regions that are involved in perceptual processing; some of the same regions may contribute to explicit memory. The hippocampal formation and prefrontal cortex also play important roles in explicit memory. Evidence is presented from recent PET scanning studies that suggests that frontal regions are associated with intentional strategic efforts to retrieve recent experiences, whereas the hippocampal formation is associated with some aspect of the actual recollection of an event.     

Key Features of Human Episodic Recollection in the Cross-Episode Retrieval of Rat Hippocampus Representations of Space

Neurophysiological studies focus on memory retrieval as a reproduction of what was experienced and have established that neural discharge is replayed to express memory. However, cognitive psychology has established that recollection is not a verbatim replay of stored information. Recollection is constructive, the product of memory retrieval cues, the information stored in memory, and the subject''s state of mind. We discovered key features of constructive recollection embedded in the rat CA1 ensemble discharge during an active avoidance task. Rats learned two task variants, one with the arena stable, the other with it rotating; each variant defined a distinct behavioral episode. During the rotating episode, the ensemble discharge of CA1 principal neurons was dynamically organized to concurrently represent space in two distinct codes. The code for spatial reference frame switched rapidly between representing the rat''s current location in either the stationary spatial frame of the room or the rotating frame of the arena. The code for task variant switched less frequently between a representation of the current rotating episode and the stable episode from the rat''s past. The characteristics and interplay of these two hippocampal codes revealed three key properties of constructive recollection. (1) Although the ensemble representations of the stable and rotating episodes were distinct, ensemble discharge during rotation occasionally resembled the stable condition, demonstrating cross-episode retrieval of the representation of the remote, stable episode. (2) This cross-episode retrieval at the level of the code for task variant was more likely when the rotating arena was about to match its orientation in the stable episode. (3) The likelihood of cross-episode retrieval was influenced by preretrieval information that was signaled at the level of the code for spatial reference frame. Thus key features of episodic recollection manifest in rat hippocampal representations of space.     

Intra- and inter-item associations doubly dissociate the electrophysiological correlates of familiarity and recollection

Single-process models of recognition memory posit that recognizing is based on a unidimensional value of global memory strength. By contrast, dual-process models propose the existence of two independent processes subserving the explicit recognition of previously encountered episodes, namely "familiarity" and "recollection." Familiarity represents a noncontextual form of recognition that may only support the retrieval of associative information when the to-be-associated information can be unitized, such as when two photographs depicting the same person are memorized (intra-item associations). Conversely, recollection enables retrieving associations between arbitrarily linked information, such as associations between photographs of different persons (inter-item associations). By measuring event-related brain potentials (ERPs), we obtained a double dissociation of familiarity and recollection that strongly favors dual-process accounts of recognition memory: the electrophysiological correlate of familiarity was significantly larger for intra- than for inter-item associations. Conversely, the electrophysiological correlate of recollection was significantly larger for inter- than for intra-item associations.     

Components of episodic memory: the contribution of recollection and familiarity

The examination of recognition memory confidence judgements indicates that there are two separate components or processes underlying episodic memory. A model that accounts for these results is described in which a recollection process and a familiarity process are assumed to contribute to recognition memory performance. Recollection is assumed to reflect a threshold process whereby qualitative information about the study event is retrieved, whereas familiarity reflects a classical signal-detection process whereby items exceeding a familiarity response criterion are accepted as having been studied. Evidence from cognitive, neuropsychological and neuroimaging studies indicate that the model is in agreement with the existing recognition results, and indicate that recollection and familiarity are behaviourally, neurally and phenomenologically distinct memory retrieval processes.