Search

Storage and retrieval of data in a computer memory play a major role in system performance. Traditionally, computer memory organization is ‘static’—i.e. it does not change based on the application-specific characteristics in memory access behaviour during system operation. Specifically, in the case of a content-operated memory (COM), the association of a data block with a search pattern (or cues) and the granularity (details) of a stored data do not evolve. Such a static nature of computer memory, we observe, not only limits the amount of data we can store in a given physical storage, but it also misses the opportunity for performance improvement in various applications. On the contrary, human memory is characterized by seemingly infinite plasticity in storing and retrieving data—as well as dynamically creating/updating the associations between data and corresponding cues. In this paper, we introduce BINGO, a brain-inspired learning memory paradigm that organizes the memory as a flexible neural memory network. In BINGO, the network structure, strength of associations, and granularity of the data adjust continuously during system operation, providing unprecedented plasticity and performance benefits. We present the associated storage/retrieval/retention algorithms in BINGO, which integrate a formalized learning process. Using an operational model, we demonstrate that BINGO achieves an order of magnitude improvement in memory access times and effective storage capacity using the CIFAR-10 dataset and the wildlife surveillance dataset when compared to traditional content-operated memory.

This study examined the independent and combined effects of high-intensity interval training (HIIT) and flaxseed oil supplementation on cognitive/executive functions in middle-aged rats. Hippocampal neurotropic brain factor (BDNF) and tyrosine kinase receptor B (TrkB) gene expression were also measured. Animals were randomly divided into groups including no exercise control and saline (CS), no exercise control and flaxseed oil supplement (CF), exercise training-and saline (TS) and exercise training and flaxseed oil supplement (TF). The training groups undertook a program of HIIT (10 weeks, five sessions per week) and the supplement groups received flaxseed oil supplement (300 mg/kg). The results showed that HIIT and flaxseed oil supplementation independently had positive effects on memory and learning (P

This review provides an update on the neurocognitive phenotype of pediatric obstructive sleep apnea (OSA). Pediatric OSA is associated with neurocognitive deficits involving memory, learning, and executive functioning. Adenotonsillectomy (AT) is presently accepted as the first line surgical treatment for pediatric OSA, but the executive function deficits do not resolve post-surgery, and the timeline for recovery remains unknown. This finding suggests that pediatric OSA potentially causes irreversible damage to multiple areas of the brain. The focus of this review is the hippocampus, one of the 2 major sites of postnatal neurogenesis, where new neurons are formed and integrated into existing circuitry and the mammalian center of learning/memory functions. Here, we review the clinical phenotype of pediatric OSA, and then discuss existing studies of OSA on different cell types in the hippocampus during critical periods of development. This will set the stage for future study using preclinical models to understand the pathogenesis of persistent neurocognitive dysfunction in pediatric OSA.

Dementia is a set of symptoms that include worsening of the routine of cognitive tasks, learning, reproducibility, and gait disturbances beyond typical aging. Activated c AMP can produce anti-apoptosis activity, neuroprotective activity, motor improvement, and cognitive enhancement activity. Cilostazol can increase c AMP levels, so this study aimed to evaluate the influence of cilostazol on learning-memory and motor coordination by rodent models. The rats were divided into 5 and 6 groups with 6 rats in each to test the hypothesis respectively. Before MES seizure induction the rats were trained for conditioned avoidance response for 14 days and the best one was selected for assessment. The performance of intervention treated groups to determine the memory retention effect was measured by applying a fixed number of shocks. The intervention treated groups were tested for motor coordination performance by rotarod test (4-45 RPM accelerating speed for 5 min) after 30 and 60 min. The latency time of each rat falls off from the rod for the first time was noted. The results were presented as Mean ± SD, tested by ordinary two way ANOVA followed by Tukey's multiple comparisons test. Cilostazol 100 mg/kg p.o demonstrated a significant memory enhancement activity in the conditioned avoidance response technique. Cilostazol 20mg/kg i.p alone and along with diazepam 2 mg/kg demonstrated a significant motor coordination performance in both sessions. The present study concludes that cilostazol has improved the learning & memory and motor coordination performances.

Objective: To explore the neurotoxicity and mechanism of tris(2-chloroethyl) phosphate (TCEP) exposure in mice.Methods: Total 30 adult Kunming mice were randomly divided into normal control group (...

Although neonicotinoids are among the major classes of pesticides that affect mammalian nervous systems, little is known about sex differences in their effects. This study aimed to examine whether the neurobehavioral effects of a neonicotinoid, clothianidin (CLO), differed between sexes. Male and female C57BL/6N mice were orally administered CLO (5 or 50 mg/kg) at or below the chronic no-observed-adverse-effect-level (NOAEL) and sub- jected to behavioral tests of emotional and learning functions. Changes in neuroactivity in several brain regions and the concentrations of CLO and its metabolites in blood and urine were measured. Acute CLO exposure caused sex-related behavioral effects; decreases in locomotor activities and elevation of anxiety-like behaviors were more apparent in males than in females. In addition, male-specific impairment of short- and long-term learning memory by CLO exposure was observed in both the novel recognition test and the Barnes maze test. Male- dominant increases in the number of c-fos positive cells were observed in the paraventricular thalamic nu- cleus in the thalamus and in the dentate gyrus in the hippocampus, which are related to the stress response and learning function, respectively. The concentrations of CLO and most metabolites in blood and urine were higher in males. These results support the notion that male mice are more vulnerable than females to the neuro- behavioral effects of CLO and provide novel insights into the risk assessment of neonicotinoids in mammalian neuronal function.

Fluoride occurs naturally in the terrestrial and aquatic environment and is a major component in tea. Prolonged fluoride exposure alters metabolic activity in several aquatic invertebrates. For the first time, we investigated the effects of fluoride on cognition in the pond snail Lymnaea stagnalis as it is capable of a higher form of associative learning called configural learning. We first showed suppressive effects of black tea and fluoride on feeding (i.e., rasping) behavior. We then investigated how fluoride may alter cognition by introducing fluoride (1.86 mg/L) before, during, after, a day before and a week before the snails underwent the configural learning training procedure. Our results show that any 45-min exposure to fluoride (before, during or after a configural learning training procedure) blocks configural learning memory formation in Lymnaea and these effects are long-lasting. One week after a fluoride exposure, snails are still unable to form a configural learning memory and this result is upheld when the snails are exposed to a lower concentration of fluoride, one which is naturally occurring in ponds that a wild strain of Lymnaea can be found (0.3 mg/L). Thus, fluoride obstructs configural learning memory formation in a fluoride-naive, inbred strain of Lymnaea.

BackgroundCurrent evidence-based treatments for post-traumatic stress disorder (PTSD) are efficacious in only part of PTSD patients. Therefore, novel neurobiologically-informed approaches are urgently needed. Clinical and translational neuroscience point to altered learning and memory processes as key in (models of) PTSD psychopathology. We extended this notion by clarifying at a meta-level i) the role of information valence, i.e. neutral versus emotional/fearful, and ii) comparability between clinical and preclinical phenotypes. We hypothesized that, cross-species, neutral versus emotional/fearful information processing is, respectively, impaired and enhanced in PTSD.MethodsThis preregistered meta-analysis involved a literature search on PTSD+Learning/Memory+Behavior, performed in PubMed. First, the effect of information valence was estimated with a random-effects meta-regression. Then sources of variation were explored with a random forest-based analysis.ResultsThe analyses included 92 clinical (N=6732 humans) and 182 preclinical (N=6834 animals) studies. A general impairment of learning, memory and extinction processes was observed in PTSD patients, regardless of information valence. Impaired neutral learning/memory and fear extinction were also present in animal models of PTSD. Yet, PTSD enhanced fear/trauma memory in preclinical studies and impaired emotional memory in patients. Clinical data on fear/trauma memory was limited. Mnemonic phase and valence explained most variation in rodents but not humans.ConclusionsImpaired neutral learning/memory and fear extinction show very stable cross-species PTSD phenotypes. These could be targeted for novel PTSD treatments, building on neurobiological animal studies. We argue that seemingly cross-species discrepancies in emotional/fearful memory deserve further study; until then animal models targeting this phenotype should be applied with care.

N6-methyladenosine (m6A) modification, as the most prevalent internal modification on mRNA, has been implicated in many biological processes through regulating mRNA metabolism. Given that m6A modification is highly enriched in the mammalian brain, this dynamic modification provides a crucial new layer of epitranscriptomic regulation of the nervous system. Here, in this review, we summarize the recent progress on studies of m6A modification in the mammalian nervous system ranging from neuronal development to basic and advanced brain functions. We also highlight the detailed underlying mechanisms in each process mediated by m6A writers, erasers, and readers. Besides, the involvement of dysregulated m6A modification in neurological disorders and injuries is discussed as well.

Aging, characterized by a time-dependent functional decline of physiological integrity, is the major independent risk factor for many neurodegeneration diseases. Therefore, it’s necessary to look for natural food supplements to extend the healthy lifespan of aging people. We here treated normal aging mice with acer truncatum seed oil, and found that the seed oil significantly improved the learning and memory ability. Proteomics revealed that the seed oil administration changed many proteins expression involving in biological processes, including complement and coagulation cascades, inflammatory response pathway and innate immune response. BDNF/TrkB signaling pathway was also activated by acer truncatum seed oil treatment. And the seed oil administration increased the expression of postsynaptic related proteins including PSD95, GluA1, and NMDAR1, and decreased the mRNA level of inflammatory factors containing IL-1β, TNF-α, and IL-6. These findings suggest that acer truncatum seed oil holds a promise as a therapeutic food supplement for delaying aging with multiple mechanisms.

ObjectiveThis study investigated the effects of acute or chronic ketamine administration on learning and memory function as well as levels of brain-derived neurotrophic factor (BDNF) in the hippocampus and blood in order to explore the potential correlation between learning-memory dysfunction and ketamine.MethodsRats were treated with 25 mg/kg ketamine for 3 d (n = 20) or 14 d (n = 20). Saline-treated rats were used as controls. The Morris water maze test was used to evaluate spatial learning and memory after 10 d of withdrawal. The level of BDNF in serum and the hippocampus were measured by ELISA.ResultsThe number of platform crossings and residence time in the target platform quadrant were significantly reduced in ketamine 3 d and 14 d groups than in the saline controls (both p < 0.05). In addition, the average escape latency of ketamine 3 d and 14 d groups were significantly longer than that of the saline 3 d and 14 d groups (p < 0.0001), respectively. Further examination found that only serum samples from ketamine 14 d group showed significantly decreased BDNF level compared to that from saline 14 d groups (p < 0.05). However, no differences were detected in hippocampus samples.ConclusionChronic ketamine exposure (25 mg/kg) causes spatial learning and memory deficits in SD rats, which may be associated with decreased serum BDNF levels.

In plants, the acquisition, processing and storage of empirical information can result in the modification of their behavior according to the nature of the stimulus, and yet this area of research remained relatively understudied until recently. As the body of evidence supporting the inclusion of plants among the higher organisms demonstrating the adaptations to accomplish these tasks keeps increasing, the resistance by traditional botanists and agricultural scientists, who were at first cautious in allowing the application of animal models onto plant physiology and development, subsides. However, the debate retains much of its heat, a good part of it originating from the controversial use of nervous system terms to describe plant processes. By focusing on the latest findings on the cellular and molecular mechanisms underlying the well established processes of Learning and Memory, recognizing what has been accomplished and what remains to be explored, and without seeking to bootstrap neuronal characteristics where none are to be found, a roadmap guiding towards a comprehensive paradigm for Learning and Memory in plants begins to emerge. Meanwhile the applications of the new field of Plant Gnosophysiology look as promising as ever.

In recent era there is competition in each and every field, so there is lot of mental stress or mental disorder seen. In modern medicine there are various drugs such as antipsychotic, antiepileptic, mood stabilizer etc. which have certain adverse effect such as drowsiness, dizziness, memory loss etc. But Ayurveda certainly has an answer, there are total 112 formulations mentioned in classical text for physco neurological disorder i.e., Unmad and Apasmar, out of these there are total 25 herbo-mineral formulations and Unmad Gaja Kesari Rasa II (UGK II) is one of them. Present study was done to evaluate Learning memory effect of Unmad Gaja Kesari Rasa II a herbo-mineral compound. Cook’s and widely model was used to evaluate learning memory activity. Total 30 wistar rats were classified into 5 groups each containing 6 rats. Human dose was extrapolated with extrapolating factor 0.018 and drug dose was given to control I and II, standard, test x and 2x group, after that learning and Relearning trails were given and avoidance, escape and no response was observed. It has been established that UGK II (Rasa Kamdhenu i.e.; R.K Unmad Chikitsa/9-12) has effective role in learning and memory activity.

Synaptic plasticity is widely believed to be the cellular basis of learning and memory. It is influenced by various factors including development, sensory experiences, and brain disorders. Long-term synaptic plasticity is accompanied by protein synthesis and trafficking, leading to structural changes of the synapse. In this review, we focus on the synaptic structural plasticity, which has mainly been studied with in vivo two-photon laser scanning microscopy. We also discuss how a special type of synapses, the multi-contact synapses (including those formed by multi-synaptic boutons and multi-synaptic spines), are associated with experience and learning.

We investigated the effects of environmental enrichment on the cognitive abilities of pharaoh cuttlefish, Sepia pharaonis, which were reared from day seven in four different environments: isolated, poor, standard, and enriched. First, we used "prawn-in-the-tube" to test whether environmental enrichment affects the ontogeny of learning and memory of S. pharaonis. The results showed that cuttlefish could usually learn the task regardless of their age and environment. At early age (74 - 81 d), cuttlefish from the isolated environment memorized the task for 24h. However, at later age (104 - 171 d), the isolated cuttlefish were unable to remember the task. In addition, cuttlefish from the poor environment could not memorize the task at all ages examined. Cuttlefish from the standard environment could memorize the task in later ages (134 - 171 d). In contrast, cuttlefish from the enriched environment could memorize the task at all ages examined. Second, we examined the effect of environmental enrichment on the ontogeny of depth perception of S. pharaonis by observing their hunting behavior. Distance from the prey during hunting was always greater in isolated cuttlefish than those from the other three environments. In addition, hunting success and number of prey captured were always lowest in the isolated cuttlefish for all ages. In contrast, hunting success was always the highest in cuttlefish from the enriched environment. These variations in behavior among cuttlefish raised in different environments suggest that the visual/tactic input derived from social and physical factors of the surrounding environment could promote maturation of learning, memory, and depth perception in S. pharaonis.

Behavioural changes can be caused by pathology within any body system, while cognitive changes stem from alterations within the brain. A variety of cognition tests have been used to assess cognitive abilities in canines, with most research focusing on ageing processes. Learning and memory can be evaluated using such cognitive tasks that include, delayed non-match to position, sensory discrimination tasks, attention tasks and reversal learning tasks. The way in which an individual learns, stores and recalls information depends on their capacity of perception and memory. Ageing and disease can alter memory capabilities by affecting brain structures and neuronal pathways. The impact of various disease states upon cognition in dogs is unknown. The ability to understand the cognitive deficits associated with ageing and disease processes deepens our understanding of patient needs and provides new directions to evaluate treatments.

The familiarity difference cue has been regarded as a general cue for making inferential judgments (Honda, Abe, Matsuks, & Yamagishi in Memory and Cognition, 39(5), 851-863, 2011; Schwikert & Curran in Journal of Experimental Psychology: General, 143(6), 2341-2365, 2014). The current study tests a model of inference based on familiarity differences that encompasses the recognition heuristic (Goldstein & Gigerenzer, 1999, Goldstein & Gigerenzer in Psychological Review, 109(1), 75-90, 2002). In two studies, using a large pool of stimuli, participants rated their familiarity of cities and made choices on a typical city-size task. The data were fitted with the r-s model (Hilbig, Erdfelder, & Pohl in, Journal of Experimental Psychology: Learning Memory and Cognition, 37(4), 827-839, 2011), which was adapted to include familiarity differences. The results indicated that people used the familiarity difference cue because the participants ignored further knowledge in a substantial number of cases when the familiarity difference cue was available. An analysis of reaction-time data further indicated that the response times were shorter for heuristic judgments than for knowledge-only-based judgments. Furthermore, when knowledge was available, the response times were shorter when knowledge was congruent with a heuristic cue than when it was in conflict with it. Differences between the familiarity difference cue and the fluency heuristic (Schooler & Hertwig, 2005, Psychological Review, 112, 610-628) are discussed.

In the field of brain research, neurons have long held the center of attention. But in recent years, some researchers are starting to expand their focus beyond neurons to a long-overlooked structure called the perineuronal net. Lattice-like elements called perineuronal nets wrap around certain neurons, sharing components with cartilage. Researchers constructed this image of perineuronal nets in the mouse visual cortex using a super-resolution microscope and a fluorescent marker that labels certain sugar-rich molecules. Image courtesy of Yaron Sigal, Xiaowei Zhuang, and Takao Hensch (Harvard University, Cambridge, MA). Discovered in the late 1800s, this lattice-like element wraps around certain neurons and shares some components with cartilage. But far from providing mere structural support, growing evidence suggests that perineuronal nets, which are highly organized aggregates of proteins and sugar chains, help regulate the brain’s ability to make new connections and tweak existing ones. Researchers are now eager to understand how these nets may contribute to healthy brain function, as well as disease. This modern revival stems from a chance meeting between two neuroscientists about 2 decades ago. While studying spinal cord injury in rats, James Fawcett at the University of Cambridge in the United Kingdom tested an enzyme that he hoped would help regrow severed nerves. It did, to a limited extent, but more notably, it appeared to encourage rapid rewiring and compensatory activity by spared nerves. Tommaso Pizzorusso, then at the Scuola Normale Superiore di Pisa in Italy, was intrigued by the finding. The two scientists decided to combine the treatment with studies of the developing rat visual system conducted by Pizzorusso’s group (1). The enzyme, it turns out, was degrading perineuronal nets. When the researchers applied it to the visual cortex of adult rats, they found that neural circuits returned to a younger, more malleable or “plastic” state. …

Convolutional neural networks (CNNs) have been popularly used to solve the problem of cell/nuclei classification and segmentation in histopathology images. Despite their pervasiveness, CNNs are fine-tuned on specific, large and labeled datasets as these datasets are hard to collect and annotate. However, this is not a scalable approach. In this work, we aim to gain deeper insights into the nature of the problem. We used a cervical cancer dataset with cells labeled into four classes by an expert pathologist. By employing pre-training on this dataset, we propose a one-shot learning model for cervical cell classification in histopathology tissue images. We extract regional maximum activation of convolutions (R-MAC) global descriptors and train a one-shot learning memory module with the goal of using it for various cancer types and eliminate the need for expensive, difficult to collect, large, labeled whole slide image (WSI) datasets. Our model achieved 94.6% accuracy in detecting the four cell classes on the test dataset. Further, we present our analysis of the dataset and features to better understand and visualize the problem in general.

Background Homeopathy is a form of alternative medicine in which uses highly diluted preparations that are believed to cause healthy people to exhibit symptoms similar to those exhibited by patients. The aim of this study was to investigate the effects of dragonfly (Anax imperator, Anax i.) on learning and memory in naive mice using the Morris water maze (MWM) test; moreover, the effects of dragonfly on MK-801-induced cognitive dysfunction were evaluated. Methods Male balb-c mice were treated with dragonfly (30C and 200C) or MK-801 (0.2 mg/kg) alone or concurrently (n = 10). Dragonfly (D) and MK-801 were administered subchronically for 6 days intraperitoneally 60 min and 30 min, respectively, before the daily performance of the MWM test. Results This study revealed that in the familiarization session and first session of the MWM test, Anax i. D30 significantly decreased escape latency compared to the control group, although MK-801, D30 and D200 significantly increased escape latency at the end of five acquisition sessions. Anax i. combined with dizocilpine maleate (MK-801) also significantly decreased escape latency in the familiarization session and first session of the MWM test, although this combination increased escape latency compared to the MK-801 alone group at the end of the test. Time spent in escape platform's quadrant in the probe trial significantly decreased while mean distance to platform significantly increased in MK-801, D30 and D200 groups. In the MWM test, Anax i. combined with MK-801 significantly decreased speed of the animals compared to the MK-801 alone group. General cell morphology was disturbed in the MK-801 group while D30 and D200 seemed to improve cell damage in the MK-801 group. Conclusions These results suggest that the homeopathic Anax i. can impair learning acquisition and reference memory, and it has beneficial effects on disturbed cell morphology.

Humans possess an unusual combination of traits, including our cognition, life history, demographics and geographical distribution. Many theories propose that these traits have coevolved. Such hypotheses have been explored both theoretically and empirically, with experiments examining whether human behaviour meets theoretical expectations. However, theory must make assumptions about the human mind, creating a potentially problematic gap between models and reality. Here, we employ a series of ‘experimental evolutionary simulations' to reduce this gap and to explore the coevolution of learning, memory and childhood. The approach combines aspects of theory and experiment by inserting human participants as agents within an evolutionary simulation. Across experiments, we find that human behaviour supports the coevolution of learning, memory and childhood, but that this is dampened by rapid environmental change. We conclude by discussing both the implications of these findings for theories of human evolution and the utility of experimental evolutionary simulations more generally. This article is part of the theme issue ‘Life history and learning: how childhood, caregiving and old age shape cognition and culture in humans and other animals'.

Human beings are considered as the most intelligent species on Earth. The ability to think, to create, to innovate, are the key elements which make humans superior over other existing species on Earth. Machines lack all those elements, although machines are faster than human in aspects like computing, equating etc. But humans are still more valuable than machines, due to all those previously discussed elements. Various models have been developed in last few years to create models that can think like human beings, but are not completely successful. This paper presents a new theoretical system for learning, memory management and decision making that can be used to develop highly complex systems, and shows the potential to be used for development of systems that can be used to provide the essential features to the machines to act like human beings., Comment: 3 pages (2 columns per page), 5 figures

Mortality due to opioid use has grown to the point where, for the first time in history, opioid-related deaths exceed those caused by car accidents in many states in the United States. Changes in the prescribing of opioids for pain and the illicit use of fentanyl (and derivatives) have contributed to the current epidemic. Less known is the impact of opioids on hippocampal neurogenesis, the functional manipulation of which may improve the deleterious effects of opioid use. We provide new insights into how the dysregulation of neurogenesis by opioids can modify learning and affect, mood and emotions, processes that have been well accepted to motivate addictive behaviours.

Manganese (Mn) is an essential nutrient for cellular function, however, in high concentrations is neurotoxic. The inhalatory via is the most faster to transfer Mn to brain. Mn affects the developme...

With the development of Augmented Reality (AR) technology, more and more research studies have explored the educational impact of AR technology applications. However, in the field of practical writing, few studies discussed the effectiveness of AR technology in Chinese idiom (inscription) learning. In this study we developed a Chinese idiom learning system, named Chinese Idioms Learning Card (CILC), which combined AR technology and game-based learning design. In the current state of the study, the proposed system has been developed and continues to address usability based on the advice of linguistic experts and students. Two classes of junior high school students in Taiwan will participate in continuous experiments. In the future, a mixed study will be conducted to explore effectiveness of students' self-learning in practical writing with the help of using this AR learning system.

Direct exposure to stimuli in their environment is not the only way that animals learn about important information. Individuals can infer fear from a social context through observation. Like humans, rats are very social animals, and may learn to infer information about their environment through their interactions with conspecifics. Here, we first review different models for social transmission of information in rodents. Second, we examine different modes of communication that are important to social learning. Then, we cover the different proximate factors that are thought to modulate the social transmission of information. Next, we identify social and environmental conditions that impact social learning, and finally, we conclude by revisiting social transmission through the lens of the Tinbergen framework.

Cacao or dark chocolate is a major source of flavonoids. Flavonoids are extremely potent antioxidants and anti-inflammatory agents, with known mechanisms beneficial for cardiovascular health. Howev...

Acrylamide (ACR) is a neurotoxin known to produce neurotoxicity characterized by ataxia, skeletal muscle weakness, cognitive impairment, and numbness of the extremities. Previously, investigators reported that high-dose (50 mg/kg) ACR impaired hippocampal neurogenesis and increased neural progenitor cell death; however, the influence of subchronic environmentally relevant low dose-(2, 20, or 200 μg/kg) ACRs have not been examined in adult neurogenesis or cognitive function in mice. Accordingly, the aim of the present study was to investigate whether low-dose ACR adversely affected mouse hippocampal neurogenesis and neurocognitive functions. Male C57BL/6 mice were orally administered vehicle or ACR at 2, 20, or 200 μg/kg/day for 4 weeks. ACR did not significantly alter the number of newly generated cells or produce neuroinflammation or neuronal loss in hippocampi. However, behavioral studies revealed that 200 μg/kg ACR produced learning and memory impairment. Furthermore, incubation of ACR with primary cultured neurons during the developmental stage was found to delay neuronal maturation without affecting cell viability indicating the presence of developmental neurotoxicity. These findings indicate that although exposure to in vivo low-dose ACR daily for 4 weeks exerted no apparent marked effect on hippocampal neurogenesis, in vitro observations in primary cultured neurons noted adverse effects on learning and memory impairment suggestive of neurotoxic actions.

The ability to form long-lasting memories is critical to survival and thus is highly conserved across the animal kingdom. By virtue of its complexity, this same ability is vulnerable to disruption by a wide variety of neuronal traumas and pathologies. To identify effective therapies with which to treat memory disorders, it is critical to have a clear understanding of the cellular and molecular mechanisms which subserve normal learning and memory. A significant challenge to achieving this level of understanding is posed by the wide range of distinct temporal and spatial profiles of molecular signaling induced by learning-related stimuli. In this review we propose that a useful framework within which to address this challenge is to view the molecular foundation of long-lasting plasticity as composed of unique spatial and temporal molecular networks that mediate signaling both within neurons (such as via kinase signaling) as well as between neurons (such as via growth factor signaling). We propose that evaluating how cells integrate and interpret these concurrent and interacting molecular networks has the potential to significantly advance our understanding of the mechanisms underlying learning and memory formation.

Objective: To study the effects of regional cerebral blood flow (rCBF) perfusion on learning and memory function in special brain areas and its molecular mechanism in rat. Methods: Sixty-four adult male healthy Sprague-Dawley (SD) rats were randomly divided into two groups: A false operation group and an operation group. The false operation group was randomly divided into four subgroups (A0, B0, C0, and D0) and the operation group was randomly divided into four subgroups (A, B, C, and D), with eight rats in each subgroup. The operation group underwent bilateral common carotid artery permanent ligation, while the other group only underwent a skin incision without the bilateral common carotid artery permanent ligation. Learning memory function of rats in each subgroup was measured using a Y-maze at 4 h, 8 h, 24 h, and 3 days after surgery. The rCBF in the right frontal lobe and hippocampus was detected using the Periflux PF model laser Doppler flowmetry and c-fos, c-jun, Bcl-2, and Bax protein expression in the right frontal lobe and hippocampus was measured using immunohistochemistry. Results: The rCBF in the right frontal lobule division and right hippocampus division was significantly lower in the operation group than in the false operation group (P < 0.05). The error number (EN), time to reach the target, and total reaction time (TRT) for the learning index using the Y-type labyrinth test in the operation group were significantly higher than that in the false operation group (P < 0.05); however, the active avoid rate in the operation group was significantly lower than that of the false operation group. Expression of c-fos and c-jun as well as the average absorbency in the right frontal lobule division and right hippocampus division in the operation group were significantly higher than those in the false operation group (P < 0. 05). The number of Bax and Bcl-2-positive cells was significantly higher in the operation group, and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group (P < 0.01). Conclusions: rCBF decrease can impair learning and memory function in rats, which may be related to the increased expression of c-fos, c-jun, Bcl-2, and Bax proteins in the frontal cortex and hippocampus. Citation Xu CL, Wu WH, Kong LB. Effects of regional cerebral blood flow perfusion on learning and memory function

The associations between consumption of a high-fat or ‘Western’ diet and metabolic disorders such as obesity, diabetes, and cardiovascular disease have long been recognized and a great deal of evidence now suggests that diets high in fat can also have a profound impact on the brain, behavior, and cognition. Here, we will review the techniques most often used to assess learning and memory in rodent models and discuss findings from studies assessing the cognitive effects of high-fat diet consumption. The review will then consider potential underlying mechanisms in the brain and conclude by reviewing emerging literature suggesting that maternal consumption of a high-fat diet may have effects on the learning and memory of offspring.

There are a variety of chemicals, including pharmaceuticals, that alter neurobehavior following developmental exposure and guidelines for the conduct of studies to detect such effects by statute in the United States and Europe. Guidelines for Developmental Neurotoxicity Testing (DNT) studies issued by the U.S. Environmental Protection Agency (EPA) under prevailing law and European Organization for Economic Cooperation and Development (OECD) recommendations to member countries provide that such studies include a series of neurobehavioral and neuropathological assessments. Among these are assessment of cognitive function, specifically learning and memory. After reviewing 69 DNT studies submitted to the EPA, tests of learning and memory were noted to have detected the lowest observed adverse effect level (LOAELs) less frequently than behavioral tests of locomotor activity and acoustic/auditory startle, but slightly more than for the developmental Functional Observational Battery (devFOB; which is less extensive than the full FOB), but the reasons for the lower LOAEL detection rate for learning and memory assessment could not be determined. A major concern identified in the review, however, was the adequacy of the methods employed in these studies rather than on the importance of learning and memory to the proper assessment of brain function. Accordingly, a symposium was conducted to consider how the guidelines for tests of learning and memory might be improved. Four laboratories with established histories investigating the effects of chemical exposures during development on learning, memory, and attention, were invited to review the topic and offer recommendations, both theoretical and practical, on approaches to improve the assessment of these vital CNS functions. Reviewers were asked to recommend methods that are grounded in functional importance to CNS integrity, well-validated, reliable, and amenable to the context of regulatory studies as well as to basic research on the underlying processes they measure. This Introduction sets the stage for the reviews by providing the background and regulatory context for improved tests for learning and memory in DNT and other regulatory studies, such as single- or multi-generational studies where similar methods are incorporated.

The objective of this study was to investigate the impact of knowledge representations on problem-oriented learning in online learning environments. The study compared the impact of knowledge map representation with traditional hierarchical representation with regard to learning memory and problem-solving performance. Twenty-nine students participated in an experiment in which they studied online materials with the goal of solving two programming problems (simple and complex). It was found that participants who used the hierarchical representation read in the depth-first sequence, whereas participants who used the knowledge map representation read in a sequence reflecting the system running mechanism implied by the graphical representation. In addition, participants who used the knowledge map representation had better memory of the learning content, especially about relations between knowledge nodes. When solving the complex problem, participants who used the knowledge map representation made a deeper ana...

The aim of this study was to investigate the effect of phosphatidylserine (PS) on memory of patients and rats with Alzheimer's disease (AD). In total, 57 AD patients were recruited from our hospital, and were divided into two groups: 25 in the control group and 32 in the observation group. Next, 300 mg/d of PS was given to the rats in the observation group for 12 continuous weeks based on the control group. AD rats were divided into three groups: control group, PS 30 mg/kg group, and PS 15 mg/kg group. Learning memory ability and free radical levels in the brain were detected after treatment. In AD patients, vocabulary and picture matching scores in the two treatment groups increased after treatment (P < 0.05). Moreover, the scores in the treated group were significantly greater than the control group (P < 0.05). In AD rats, PS treatment reduced the escape latent period of AD rats, increased SOD and OH(-), and decreased acetylcholinesterase levels (P < 0.05). Compared with PS 15 mg/kg, PS 30 mg/kg group was significantly more efficacious (P < 0.05). Compared with the AD model group, hippocampal cells showed normal arrangement, karyopyknosis decreased, and the pathological changes in the two PS groups were considerable. In conclusion, PS decreased cholinesterase, improved memory, and improved hippocampal inflammation injury in AD brains by increasing SOD and OH(-) levels.

Neuronal plasticity occurs in associative memory. Associative memory cells are recruited for the integration and storage of associated signals. The coordinated refinements and interactions of associative memory cells including glutamatergic and GABAergic neurons remain elusive, which we have examined in a mouse model of associative learning. Paired olfaction, tail and whisker stimulations lead to odorant-induced and tail-induced whisker motions alongside whisker-induced whisker motion. In mice that show this cross-modal associative memory, barrel cortical glutamatergic and GABAergic neurons are recruited to encode the newly learned odor and tail signals alongside the innate whisker signal. These glutamatergic neurons are functionally upregulated, and GABAergic neurons are refined in a homeostatic manner. The mutual innervations between these glutamatergic and GABAergic neurons are upregulated. Therefore, the co-activations of sensory cortices by pairing the input signals recruit their glutamatergic and GABAergic neurons to be associative memory cells, which undergo coordinated refinement among glutamatergic and GABAergic neurons as well as homeostatic plasticity among subcellular compartments in order to drive these cells toward the optimal state for the integrative storage of associated signals.

Background Sevoflurane may be associated with neural toxicity in the developing brain, but the mechanism is still unclear. Phosphorylated extracellular signal-regulated kinases 1/2 (pERK1/2) are important for developing neurons. The aim of our study was to investigate the effects of sevoflurane on spatial learning and memory and on expression of pERK1/2 in hippocampus of neonatal rats. Methods Sixty-three neonatal rats were randomly divided into three groups: control group, sevoflurane (sevo) group, and sham group. Rats in the control group were placed in a plastic chamber flushed continuously for 4 h with air alone, rats in the sevo group were exposed in 5% sevoflurane and air for 4 h, and rats in the sham group were exposed in 5% carbon dioxide and air for 4 h, with identical flow rates for all groups. All three groups were subjected to Morris water maze test 1 day after sevoflurane exposure. Moreover, expression of pERK1/2 was determined by immunochemistry and Western blot at 1, 3, and 6 weeks after exposure. Results Compared with the control group, the escape latency was longer in sevo group and the expression of pERK1/2 was significantly inhibited in the sevo group (P

Epigenetic regulation of cellular identity and function is at least partly achieved through changes in covalent modifications on DNA and histones. Much progress has been made in recent years to understand how these covalent modifications affect cell identity and function. Despite the advances, whether and how epigenetic factors contribute to memory formation is still poorly understood. In this review, we discuss recent progress in elucidating epigenetic mechanisms of learning and memory, primarily at the DNA level, and look ahead to discuss their potential implications in reward memory and development of drug addiction.

During the last decade, network approaches became a powerful tool to describe protein structure and dynamics. Here, we describe first the protein structure networks of molecular chaperones, then characterize chaperone containing sub-networks of interactomes called as chaperone-networks or chaperomes. We review the role of molecular chaperones in short-term adaptation of cellular networks in response to stress, and in long-term adaptation discussing their putative functions in the regulation of evolvability. We provide a general overview of possible network mechanisms of adaptation, learning and memory formation. We propose that changes of network rigidity play a key role in learning and memory formation processes. Flexible network topology provides "learning competent" state. Here, networks may have much less modular boundaries than locally rigid, highly modular networks, where the learnt information has already been consolidated in a memory formation process. Since modular boundaries are efficient filters of information, in the "learning competent" state information filtering may be much smaller, than after memory formation. This mechanism restricts high information transfer to the "learning competent" state. After memory formation, modular boundary-induced segregation and information filtering protect the stored information. The flexible networks of young organisms are generally in a "learning competent" state. On the contrary, locally rigid networks of old organisms have lost their "learning competent" state, but store and protect their learnt information efficiently. We anticipate that the above mechanism may operate at the level of both protein-protein interaction and neuronal networks., 19 pages, 2 Figures, 1 Table, 173 references

While protein-coding genes have been widely studied in learning and memory, the role of the non-coding genome has only recently been investigated. With advances in high throughput sequencing technologies and functional profiling methods, multiple long noncoding RNAs (lncRNAs) have been functionally and mechanistically linked with neurobiological processes related with learning and memory, as well disorders that lead to memory impairment. However, these macromolecules are still a subject of controversy and intense scrutiny regarding the proper criteria for determining their functionality and their evolution in the central nervous system. Recent studies have implicated multiple lncRNAs as critical regulators of gene expression in the central nervous system and mediate learning processes. In this review, we explore possible explanations for how lncRNAs are evolved in our central nervous system, discuss our current understanding of their involvement in learning and memory related disorders, and describe emerging tools for studying lncRNAs.

Abundant evidence from both field and lab studies has established that conspecific vocalizations (CVs) are of critical ecological significance for a wide variety of species, including humans, non-human primates, rodents, and other mammals and birds. Correspondingly, a number of experiments have demonstrated behavioral processing advantages for CVs, such as in discrimination and memory tasks. Further, a wide range of experiments have described brain regions in many species that appear to be specialized for processing CVs. For example, several neural regions have been described in both mammals and birds wherein greater neural responses are elicited by CVs than by comparison stimuli such as heterospecific vocalizations, nonvocal complex sounds, and artificial stimuli. These observations raise the question of whether these regions reflect domain-specific neural mechanisms dedicated to processing CVs, or alternatively, if these regions reflect domain-general neural mechanisms for representing complex sounds of learned significance. Inasmuch as CVs can be viewed as complex combinations of basic spectrotemporal features, the plausibility of the latter position is supported by a large body of literature describing modulated cortical and subcortical representation of a variety of acoustic features that have been experimentally associated with stimuli of natural behavioral significance (such as food rewards). Herein, we review a relatively small body of existing literature describing the roles of experience, learning, and memory in the emergence of species-typical neural representations of CVs and auditory system plasticity. In both songbirds and mammals, manipulations of auditory experience as well as specific learning paradigms are shown to modulate neural responses evoked by CVs, either in terms of overall firing rate or temporal firing patterns. In some cases, CV-sensitive neural regions gradually acquire representation of non-CV stimuli with which subjects have training and experience. These results parallel literature in humans describing modulation of responses in face-sensitive neural regions through learning and experience. Thus, although many questions remain, the available evidence is consistent with the notion that CVs may acquire distinct neural representation through domain-general mechanisms for representing complex auditory objects that are of learned importance to the animal. This article is part of a Special Issue entitled “Communication Sounds and the Brain: New Directions and Perspectives”.