情绪记忆权衡与拓宽效应及其认知神经机制

情绪图片能比中性图片产生更好的记忆效果。然而近年研究发现，对于复杂场景图片，情绪诱发的记忆增强并非单一的过程，而包含两个相反的现象：情绪信息既可能选择性地增强场景中具有情感色彩的中心记忆，并带来背景记忆的下降，诱发情绪记忆权衡效应；也可能同时增强中心和背景记忆，诱发情绪记忆拓宽效应。两种现象的发生取决于记忆信息特性（情绪效价、中心-背景联结程度）及记忆过程（编码、巩固和提取）相关的诸多因素，而其背后的机制仍未明晰。当前该领域存在情绪记忆权衡是否是一种不由注意所介导的自动化过程的争论，另有少数研究考察了与记忆权衡效应相关的脑网络，而针对记忆拓宽效应机制的研究仍较为匮乏。未来需从行为和神经层面，对比情绪诱发的记忆权衡与拓宽效应的发生机制，针对二者的自动化特性、涉及的记忆表征形式等问题深入研究，并将这些效应拓展至空间之外的维度，以系统揭示情绪信息选择性增强记忆现象背后的深层原因。     

Molecular pharmacological dissection of short- and long-term memory

1. It has been discussed for over 100 years whether short-term memory (STM) is separate from, or just an early phase of, long-term memory (LTM). The only way to solve this dilemma is to find out at least one treatment that blocks STM while keeping LTM intact for the same task in the same animal.2. The effect of a large number of treatments infused into the hippocampus, amygdala, and entorhinal, posterior parietal or prefrontal cortex on STM and LTM of a one-trial step-down inhibitory avoidance task was studied. The animals were tested at 1.5 h for STM, and again at 24 h for LTM. The treatments were given after training.3. Eleven different treatments blocked STM without affecting LTM. Eighteen treatments affected the two memory types differentially, either blocking or enhancing LTM alone. Thus, STM is separate from, and parallel to the first hours of processing of, LTM of that task.4. The mechanisms of STM are different from those of LTM. The former do not include gene expression or protein synthesis; the latter include a double peak of cAMP-dependent protein kinase activity, accompanied by the phosphorylation of CREB, and both gene expression and protein synthesis.5. Possible cellular and molecular events that do not require mRNA or protein synthesis should account for STM. These might include a hyperactivation of glutamate AMPA receptors, ribosome changes, or the exocytosis of glycoproteins that participate in cell addition.     

Vasopressin analogues and spatial short-term memory in rats

The effect of vasopressin analogues on short-term memory was tested in the 12-arm radial maze. After the first 6 choices rats (n=6) were removed from the apparatus and allowed to complete the remaining 6 choices 20 min later. Whereas desgly-NH₂-VP, AVP, dAVP and DAVP (3.0 μ/kg) administered 40 min before or immediately after the first 6 choices did not change the incidence of errors in the second series of choices (2.0 errors under control conditions), similarly applied dDAVP deteriorated the rat's performance almost to the chance level of 3 errors. The significance of short-term memory tests for assessing the mnestic role of peptide hormones is stressed.     

生态学中的植物记忆研究

近年来,植物记忆研究为深入理解种群分布格局、群落构建、群落演替等生态学过程提供了新的视角,因此备受生态学家的关注。在介绍生态胁迫记忆、表观遗传记忆、生态记忆、土壤记忆概念的基础上,综述了近几年来相关领域在生态学研究中的最新进展,并提出了植物记忆在生态学研究中值得关注的方向,以期为全面深入的理解生态学过程提供一个新的角度。     

Vasopressin analogues and spatial working memory in the 24-arm radial maze

The effect of vasopressin analogues dAVP, dDAVP, and desgly NH₂ dDAVP on working memory was tested in the 24-arm radial maze in twelve 6-month-old and twelve 19-month-old rats. No age dependent effects were found. All three peptides tested (3 μg/kg) tended to improve the performance but only the desgly NH₂ dDAVP significantly decreased the number of errors. A second application of desgly NH₂ dDAVP was ineffective. The specificity of activation of memory mechanisms by desgly NH₂ dDAVP can be questioned.     

Episodic-like memory: pigeons can report location pecked when unexpectedly asked

Pigeons were tested for their ability to report the location they recently pecked, without prior experience having to do so. They were first pretrained to report the location that they had just pecked. They were then trained on a conditional discrimination to associate yellow and blue samples with vertical and horizontal comparisons, respectively, independent of comparison location. On probe trials in testing, when after choosing a vertical or horizontal line following the yellow or blue sample, the pigeons were ‘asked’ which location they had just pecked, they showed a significant tendency to choose correctly in spite of the fact that location of the correct comparison was incidental to the task. Performing on probe trials is analogous to asking the pigeons an unexpected question about their recent behavior and it is similar to the episodic memory question asked of humans, “What did you have for breakfast this morning?”.     

Incidental and intentional flavor memory in young and older subjects

Incidental and intentional learning and memory for 2 novel flavors were compared in young and elderly subjects. Incidental and intentional learning groups rated 2 new soups on acceptability for different occasions and were tested for memory the next day. On the first day, only the intentional group was asked to memorize the stimuli. With incidental learning, elderly and young were equally good, but the young performed better with intentional than with incidental learning, whereas the elderly did not. There were no age-related differences in perceptual discrimination. When comparing perceived flavor with the memory of it, the elderly tend to overrate intensities of remembered flavor attributes, whereas the young tend to underrate them. Memory was not related to flavor pleasantness or neophobia. Like memory for taste and texture, flavor memory seems to be mainly tuned at detecting changes and based on "feelings of not knowing" rather than on precise identification and recognition of previously encountered stimuli.     

Contingency of semantic generalization on episodic specificity varies across development

1. Download : Download high-res image (271KB)
2. Download : Download full-size image

     

Use of spatial and colour cues by foraging pine siskins (Carduelis pinus): A field study

Pine siskins (Carduelis pinus) frequently forage at known high quality food supplies such as backyard feeders. In this field study, pine siskins visited backyard feeders of differing colour and spatial position. The three feeders contained varying amounts of food in a ratio of 3:2:1. The birds quickly distributed their visits in this ratio to the three feeders. During unbaited tests, two feeders on a given day had their positions swapped. The siskins appeared to primarily use both large-scale spatial or distal cues when foraging as well as local colour cues.     

Differential Role of Hippocampal cAMP-Dependent Protein Kinase in Short- and Long-Term Memory

One-trial step-down inhibitory (passive) avoidance training is followed by two peaks of cAMP-dependent protein kinase (PKA) activity in rat CA1: one immediately after training and the other 3 h later. The second peak relies on the first: Immediate posttraining infusion into CA1 of the inhibitor of the regulatory subunit of PKA, Rp-cAMPS, at a dose that reduces PKA activity during less than 90 min, cancelled both peaks. Long-term memory (LTM) of this task measured at 24 h depends on the two peaks: Rp-cAMPS given into CA1 0 or 175 min posttraining, but not between those times, blocked LTM. However, the effect of immediate posttraining Rp-cAMPS on LTM could not be reversed by the activator of the regulatory subunit of PKA, Sp-cAMPS, given at 180 min, which suggests that, for LTM, the first peak may be more important than the second. When given at 0, 22, 45, or 90, but not at 175 min from training, Rp-cAMPS blocked short-term memory (STM) measured at 90 or 180 min. This effect of immediate posttraining Rp-cAMPS infusion on STM but not that on LTM was readily reversed by Sp-cAMPS infused 22 min later. On its own, Sp-cAMPS had effects exactly opposite to those of the inhibitor. It enhanced LTM when given at 0 or 175 min from training, and it enhanced STM when given at 0, 22, 45, or 90 min from training. These findings show that STM and LTM formation require separate PKA-dependent processes in CA1. STM relies on the continued activity of the enzyme during the first 90 min. LTM relies on the two peaks of PKA activity that occur immediately and 180 min posttraining.     

Premarin improves memory, prevents scopolamine-induced amnesia and increases number of basal forebrain choline acetyltransferase positive cells in middle-aged surgically menopausal rats

Conjugated equine estrogen (CEE) is the most commonly prescribed estrogen therapy, and is the estrogen used in the Women's Health Initiative study. While in-vitro studies suggest that CEE is neuroprotective, no study has evaluated CEE's effects on a cognitive battery and brain immunohistochemistry in an animal model. The current experiment tested whether CEE impacted: I) spatial learning, reference memory, working memory and long-term retention, as well as ability to handle mnemonic delay and interference challenges; and, II) the cholinergic system, via pharmacological challenge during memory testing and ChAT-immunoreactive cell counts in the basal forebrain. Middle-aged ovariectomized (Ovx) rats received chronic cyclic injections of either Oil (vehicle), CEE-Low (10 μg), CEE-Medium (20 μg) or CEE-High (30 μg) treatment. Relative to the Oil group, all three CEE groups showed less overnight forgetting on the spatial reference memory task, and the CEE-High group had enhanced platform localization during the probe trial. All CEE groups exhibited enhanced learning on the spatial working memory task, and CEE dose-dependently protected against scopolamine-induced amnesia with every rat receiving the highest CEE dose maintaining zero errors after scopolamine challenge. CEE also increased number of ChAT-immunoreactive neurons in the vertical diagonal band of the basal forebrain. Neither the ability to remember after a delay nor interference, nor long-term retention, was influenced by the CEE regimen used in this study. These findings are similar to those reported previously for 17 β-estradiol, and suggest that CEE can provide cognitive benefits on spatial learning, reference and working memory, possibly through cholinergic mechanisms.     

Structural and serological studies of lipopolysaccharides of Citrobacter O35 and O38 antigenically related to Salmonella

Abstract Lipopolysaccharide (LPS) was administered into sheep red blood cells (SRBC)-primed mice, and the effect of LPS on SRBC-specific memory cells was investigated. Spleen cells from SRBC-primed mice which were injected with LPS exhibited much lower in vitro secondary plaque-forming cells (PFC) responses to SRBC than those from untreated SRBC-primed mice. The in vitro anti-SRBC response of the spleen cells to LPS was also reduced. The combination experiments of B cells and T cells from SRBC-primed mice which were injected with or without LPS demonstrated that the reduction of immune responses to SRBC after administration of LPS was caused by the defect of SRBC-specific B memory cells, but not T memory cells. B cell type rosette-forming cells (RFC) for SRBC markedly decreased after injection of LPS, while PFC as antibody-forming cells did not increase subsequently. Therefore, the reduction of RFC was not due to their differentiation into PFC. The lymphoid follicles in the spleens from mice injected with LPS were stained positively by in situ nick end labeling specific for fragmented DNA. A large percentage of Ig⁺ spleen cells from SRBC-primed mice which were injected with LPS was also stained positively. The injection of glucocorticoids into SRBC-primed mice induced similar reduction of B memory cells. It was suggested that LPS might induce apoptosis of B memory cells and regulate B cell memory in antigen-nonspecific manner.     

Reduced order multiport parallel and multidirectional neural associative memories

This paper proposes multiport parallel and multidirectional intraconnected associative memories of outer product type with reduced interconnections. Some new reduced order memory architectures such as k-directional and k-port parallel memories are suggested. These architectures are, also, very suitable for implementation of spatio-temporal sequences and multiassociative memories. It is shown that in the proposed memory architectures, a substational reduction in interconnections is achieved if the actual length of original N-bit long vectors is subdivided into k sublengths. Using these sublengths, submemory matrices, T _s or W _s , are computed, which are then intraconnected to form k-port parallel or k-directional memories. The subdivisions of N-bit long vectors into k sublengths save of interconnections. It is shown, by means of an example, that more than 80% reduction in interconnections is achieved. Minimum limit in bits on k as well as maximum limit on subdivisions in k is determined. The topologies of reduced interconnectivity developed in this paper are symmetric in structure and can be used to scale up to larger systems. The underlying principal of construction, storage and retrieval processes of such associative memories has been analyzed. The effect of complexity of different levels of reduced interconnectivity on the quality of retrieval, signal to noise ratio, and storage capacity has been investigated. The model possesses analogies to biological neural structures and digital parallel port memories commonly used in parallel and multiprocessing systems.     

Incidental learning and memory for three basic tastes in food

Forty three subjects were invited under the pretence that they would take part in an experiment on hunger feelings. They came without having eaten anything that morning and received a standard breakfast containing orange juice, cream cheese on crackers and yoghurt. These products were later (when subjects returned after scoring hunger feelings during the day) used as targets amidst a set of distractors varied by adding or subtracting different amounts of two basic tastes. Orange juice was varied in sweetness and bitterness, cream cheese in sourness and bitterness and yoghurt in sweetness and sourness. The changes were made comparable by using just noticeable differences, determined in preliminary experiments with other subjects, as units of change. Two measurements of memory were compared, an absolute (indicating which were the targets) and a relative one (indicating whether the targets and distractors were more, less or equally pleasant, sweet, sour, bitter or salty as the item eaten at breakfast). Both methods showed incidental learning, but relative memory was superior. Memory differed between tastes and was partly product dependent. These experiments suggest that taste memory is tuned to detect novel and potentially dangerous stimuli rather than to remember features of earlier experienced stimuli with great precision.     

昆虫记忆的形成机制及生态适应性

介绍近十几年来利用蜜蜂Apis mellifera L.、果蝇Drosophila melanogaster Meigen和寄生蜂等昆虫对学习和记忆行为研究的成果。这些研究表明昆虫的记忆形成是多阶段的。从短时记忆向长时记忆的形成过程中,cAMP反应元件结合蛋白(cAMP response element-bindingprotein,CREB)起重要的作用;而蘑菇体是学习、记忆形成的主要位点。已有的研究还表明昆虫记忆的动态是适应于不同物种的生态学需要。这些研究为探索昆虫和其它动物记忆的形成和生态适应性提供了理论基础。     

Morris water maze: a versatile and pertinent tool for assessing spatial learning and memory

Since its development about 40 years ago (1981–2021), Morris water maze has turned into a very popular tool for assessing spatial learning and memory. Its many advantages have ensured its pertinence to date. These include its effectiveness in evaluating hippocampal-dependent learning and memory, exemption from motivational differences across diverse experimental manipulations, reliability in various cross-species studies, and adaptability to many experimental conditions with various test protocols. Nonetheless, throughout its establishment, several experimental and analysis loopholes have galvanized researchers to assess ways in which it could be improved and adapted to fill this gap. Therefore, in this review, we briefly summarize these developments since the early years of its establishment through to the most recent advancements in computerized analysis, offering more comprehensive analysis paradigms. In addition, we discuss the adaptability of the Morris water maze across different test versions and analysis paradigms, providing suggestions with regard to the best paradigms for particular experimental conditions. Hence, the proper selection of the experimental protocols, analysis paradigms, and consideration of the assay’s limitations should be carefully considered. Given that appropriate measures are taken, with various adaptations made, the Morris water maze will likely remain a relevant tool to assess the mechanisms of spatial learning and memory.     

Focus: The Aging Brain: The Knowledge of Memory Aging Questionnaire: Factor Structure and Correlates in a Lifespan Sample

The authors examined the factor structure of the Knowledge of Memory Aging Questionnaire (KMAQ) [1] using confirmatory factor analysis in a lifespan sample of 933 individuals who ranged in age from 18 to 101. Participants were college students at Louisiana State University and adults from the community enrolled in the Louisiana Healthy Aging Study (LHAS). A two-factor solution was expected, consistent with the normal and pathological memory aging dimensions that comprise the KMAQ. A bi-factor solution with items loading on a general response bias factor and either a normal or pathological knowledge-specific factor showed good model fit. Knowledge scores were correlated with demographic and cognitive performance variables. Implications of these data for clinical settings and research are considered.