WorldWideScience
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HDAC inhibition modulates hippocampus-dependent long-term memory for object location in a CBP-dependent manner  

OpenAIRE

Transcription of genes required for long-term memory not only involves transcription factors, but also enzymatic protein complexes that modify chromatin structure. Chromatin-modifying enzymes, such as the histone acetyltransferase (HAT) CREB (cyclic-AMP response element binding) binding protein (CBP), are pivotal for the transcriptional regulation required for long-term memory. Several studies have shown that CBP and histone acetylation are necessary for hippocampus-dependent long-term memory...

Haettig, Jakob; Stefanko, Daniel P.; Multani, Monica L.; Figueroa, Dario X.; Mcquown, Susan C.; Wood, Marcelo A.

2011-01-01

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Long-term Mild Exercise Training Enhances Hippocampus-dependent Memory in Rats.  

Science.gov (United States)

Although exercise training improves hippocampus-related cognition, the optimum exercise intensity is still disputed. Based on the lactate threshold (LT, approximately 20?m/min on treadmill) of rats, we have shown that 2 weeks of training with stress-free mild exercise (ME, LT), comprising exercise stress, promotes adult hippocampal neurogenesis (Okamoto et al., PNAS, 2012), a potential substrate for memory improvement. These results led us to postulate that long-term ME, but not IE, training leads to improved hippocampal function as assessed with a Morris water maze (MWM) task. To test this hypothesis, we investigated the changes in physiological stress levels and MWM task performance in rats assigned to 6 weeks of sedentary control (CONT), ME-training or IE-training conditions. Results showed that, compared to the other conditions, only IE causes general adaptive syndrome (GAS), including adrenal hypertrophy, thymic atrophy and hypercorticosteronemia. In the MWM, ME led to enhanced memory, but not learning, compared with CONT, while IE produced no change in either capacity, probably due to GAS. These findings support the hypothesis that 6 weeks of continuous ME training leads to enhanced hippocampus-related memory, which may have implications for both healthy adults and subjects with low physical capacity. PMID:25429548

Inoue, K; Hanaoka, Y; Nishijima, T; Okamoto, M; Chang, H; Saito, T; Soya, H

2015-04-01

3

Gadd45b knockout mice exhibit selective deficits in hippocampus-dependent long-term memory  

OpenAIRE

Growth arrest and DNA damage-inducible ? (Gadd45b) has been shown to be involved in DNA demethylation and may be important for cognitive processes. Gadd45b is abnormally expressed in subjects with autism and psychosis, two disorders associated with cognitive deficits. Furthermore, several high-throughput screens have identified Gadd45b as a candidate plasticity-related gene. However, a direct demonstration of a link between Gadd45b and memory has not been established. The current studies fir...

Leach, Prescott T.; Poplawski, Shane G.; Kenney, Justin W.; Hoffman, Barbara; Liebermann, Dan A.; Abel, Ted; Gould, Thomas J.

2012-01-01

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MHC class I immune proteins are critical for hippocampus-dependent memory and gate NMDAR-dependent hippocampal long-term depression  

OpenAIRE

Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that specific immune proteins, members of the major histocompatibility complex class I (MHC class I), are essential for normal hippocampus-dependent memory, and...

Nelson, P. Austin; Sage, Jennifer R.; Wood, Suzanne C.; Davenport, Christopher M.; Anagnostaras, Stephan G.; Boulanger, Lisa M.

2013-01-01

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The APP-Interacting Protein FE65 is Required for Hippocampus-Dependent Learning and Long-Term Potentiation  

Science.gov (United States)

FE65 is expressed predominantly in the brain and interacts with the C-terminal domain of [beta]-amyloid precursor protein (APP). We examined hippocampus-dependent memory and in vivo long-term potentiation (LTP) at the CA1 synapses with isoform-specific FE65 knockout (p97FE65[superscript -/-]) mice. When examined using the Morris water maze,…

Wang, Yan; Zhang, Ming; Moon, Changjong; Hu, Qubai; Wang, Baiping; Martin, George; Sun, Zhongsheng; Wang, Hongbing

2009-01-01

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MHC Class I Immune Proteins Are Critical for Hippocampus-Dependent Memory and Gate NMDAR-Dependent Hippocampal Long-Term Depression  

Science.gov (United States)

Memory impairment is a common feature of conditions that involve changes in inflammatory signaling in the brain, including traumatic brain injury, infection, neurodegenerative disorders, and normal aging. However, the causal importance of inflammatory mediators in cognitive impairments in these conditions remains unclear. Here we show that…

Nelson, P. Austin; Sage, Jennifer R.; Wood, Suzanne C.; Davenport, Christopher M.; Anagnostaras, Stephan G.; Boulanger, Lisa M.

2013-01-01

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Resistance exercise improves hippocampus-dependent memory  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english It has been demonstrated that resistance exercise improves cognitive functions in humans. Thus, an animal model that mimics this phenomenon can be an important tool for studying the underlying neurophysiological mechanisms. Here, we tested if an animal model for resistance exercise was able to impro [...] ve the performance in a hippocampus-dependent memory task. In addition, we also evaluated the level of insulin-like growth factor 1/insulin growth factor receptor (IGF-1/IGF-1R), which plays pleiotropic roles in the nervous system. Adult male Wistar rats were divided into three groups (N = 10 for each group): control, SHAM, and resistance exercise (RES). The RES group was submitted to 8 weeks of progressive resistance exercise in a vertical ladder apparatus, while the SHAM group was left in the same apparatus without exercising. Analysis of a cross-sectional area of the flexor digitorum longus muscle indicated that this training period was sufficient to cause muscle fiber hypertrophy. In a step-through passive avoidance task (PA), the RES group presented a longer latency than the other groups on the test day. We also observed an increase of 43 and 94% for systemic and hippocampal IGF-1 concentration, respectively, in the RES group compared to the others. A positive correlation was established between PA performance and systemic IGF-1 (r = 0.46, P

R.C., Cassilhas; K.S., Lee; D.P., Venâncio; M.G.M., Oliveira; S., Tufik; M.T., Mello.

1215-12-01

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Long-Term Memory Improvement?  

Science.gov (United States)

Tests Piaget's interpretation of long-term memory improvement among 82 five- and six-year-old children. Concludes that there is little evidence for long-term memory improvement or for Piaget's theory of memory. (Author/RH)

Maurer, Daphne; And Others

1979-01-01

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Circadian Oscillations within the Hippocampus Support Hippocampus-dependent Memory Processing  

Directory of Open Access Journals (Sweden)

Full Text Available The ability to sustain memories over long periods of time, sometimes even a lifetime, is one of the most remarkable properties of the brain. Much knowledge has been gained over the past few decades regarding the molecular correlates of memory formation. Once a memory is forged, however, the molecular events that provide permanence are as of yet unclear. Studies in multiple organisms have revealed that circadian rhythmicity is important for the formation, stability, and recall of memories [1]. The neuronal events that provide this link need to be explored further. This article will discuss the findings related to the circadian regulation of memory-dependent processes in the hippocampus. Specifically, the circadian-controlled MAP kinase and cAMP signal transduction pathway plays critical roles in the consolidation of hippocampus-dependent memory. A series of studies have revealed the circadian oscillation of this pathway within the hippocampus, an activity that is absent in memory-deficient, transgenic mice lacking Ca2+-stimulated adenylyl cyclases. Interference with these oscillations proceeding the cellular memory consolidation period impairs the persistence of hippocampus-dependent memory. These data suggest that the persistence of long-term memories may depend upon reactivation of this signal transduction pathway in the hippocampus during the circadian cycle. New data reveals the dependence of hippocampal oscillation in MAPK activity on the SCN, again underscoring the importance of this region in maintaining the circadian physiology of memory. Finally, the downstream ramification of these oscillations in terms of gene expression and epigenetics should be considered, as emerging evidence is pointing strongly to a circadian link between epigenetics and long term synaptic plasticity.

KristinLynnEckel-Mahan

2012-04-01

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Neuromodulatory signaling in hippocampus-dependent memory retrieval.  

Science.gov (United States)

Considerable advances have been made toward understanding the molecular signaling events that underlie memory acquisition and consolidation. In contrast, less is known about memory retrieval, despite its necessity for utilizing learned information. This review focuses on neuromodulatory and intracellular signaling events that underlie memory retrieval mediated by the hippocampus, for which the most information is currently available. Among neuromodulators, adrenergic signaling is required for the retrieval of various types of hippocampus-dependent memory. Although they contribute to acquisition and/or consolidation, cholinergic and dopaminergic signaling are generally not required for retrieval. Interestingly, while not required for retrieval, serotonergic and opioid signaling may actually constrain memory retrieval. Roles for histamine and non-opioid neuropeptides are currently unclear but possible. A critical effector of adrenergic signaling in retrieval is reduction of the slow afterhyperpolarization mediated by ?1 receptors, cyclic AMP, protein kinase A, Epac, and possibly ERK. In contrast, stress and glucocorticoids impair retrieval by decreasing cyclic AMP, mediated in part by the activation of ?2 -adrenergic receptors. Clinically, alterations in neuromodulatory signaling and in memory retrieval occur in Alzheimer's disease, Down syndrome, depression, and post-traumatic stress disorder, and recent evidence has begun to link changes in neuromodulatory signaling with effects on memory retrieval. © 2014 Wiley Periodicals, Inc. PMID:25475876

Thomas, Steven A

2015-04-01

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Erythropoietin enhances hippocampal long-term potentiation and memory  

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Full Text Available Abstract Background Erythropoietin (EPO improves cognition of human subjects in the clinical setting by as yet unknown mechanisms. We developed a mouse model of robust cognitive improvement by EPO to obtain the first clues of how EPO influences cognition, and how it may act on hippocampal neurons to modulate plasticity. Results We show here that a 3-week treatment of young mice with EPO enhances long-term potentiation (LTP, a cellular correlate of learning processes in the CA1 region of the hippocampus. This treatment concomitantly alters short-term synaptic plasticity and synaptic transmission, shifting the balance of excitatory and inhibitory activity. These effects are accompanied by an improvement of hippocampus dependent memory, persisting for 3 weeks after termination of EPO injections, and are independent of changes in hematocrit. Networks of EPO-treated primary hippocampal neurons develop lower overall spiking activity but enhanced bursting in discrete neuronal assemblies. At the level of developing single neurons, EPO treatment reduces the typical increase in excitatory synaptic transmission without changing the number of synaptic boutons, consistent with prolonged functional silencing of synapses. Conclusion We conclude that EPO improves hippocampus dependent memory by modulating plasticity, synaptic connectivity and activity of memory-related neuronal networks. These mechanisms of action of EPO have to be further exploited for treating neuropsychiatric diseases.

El-Kordi Ahmed

2008-09-01

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Hippocampal Overexpression of Mutant CREB Blocks Long-Term, but Not Short-Term Memory for a Socially Transmitted Food Preference  

Science.gov (United States)

Phosphorylation of the transcription factor CREB on Ser133 is implicated in the establishment of long-term memory for hippocampus-dependent tasks, including spatial learning and contextual fear conditioning. We reported previously that training on a hippocampus-dependent social transmission of food preference (STFP) task increases CREB…

Brightwell, Jennifer J.; Countryman, Renee A.; Neve, Rachael L.; Colombo, Paul J.; Smith, Clayton A.

2005-01-01

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A Transcription Factor-Binding Domain of the Coactivator CBP Is Essential for Long-Term Memory and the Expression of Specific Target Genes  

Science.gov (United States)

Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with…

Oliveira, Ana M. M.; Brindle, Paul K.; Abel, Ted; Wood, Marcelo A.; Attner, Michelle A.

2006-01-01

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Andra long term memory project - 59277  

International Nuclear Information System (INIS)

Document available in abstract form only. Full text of publication follows: Long term memory of repositories is required by safety, reversibility and social expectations. Thus Andra has implemented since 2010 a long-term memory project to reinforce and diversify its current arrangements in this field, as well as to explore opportunities to extend memory keeping over thousands years. The project includes opportunity studies of dedicated facilities. The 'Ecotheque' and 'Geotheque' projects contribute to memory respectively through environmental and geological samples preservation. The options of creating (i) an archive centre for Andra's interim and permanent archives, (ii) an artist center to study the contribution of arts to memory preservation, (iii) a museum of radioactive waste disposal history and technology (radium industry..., sea disposal, current solutions...) are considered. Other studies provided by the project examine our heritage. This includes the continuity of languages and symbolic systems, the continuity of writing and engraving methods, the archaeology of landscapes (memory of the earths evolution, multi-century memory of industrial and agricultural landscapes), the archaeology practices (how might a future archaeologist be interested in our current activity?), the preservation of historical sites and industrial memory, the continuity of institutional organizations, the memory and history of science evolution as well as broad historyas well as broad history

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A cost of long-term memory in Drosophila  

OpenAIRE

Two distinct forms of consolidated associative memory are known in Drosophila: long-term memory and so-called anesthesia-resistant memory. Long-term memory is more stable, but unlike anesthesia-resistant memory, its formation requires protein synthesis. We show that flies induced to form long-term memory become more susceptible to extreme stress (such as desiccation). In contrast, induction of anesthesia-resistant memory had no detectable effect on desiccation resistance. This finding may hel...

Mery, Frederic; Kawecki, Tadeusz J.

2005-01-01

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Genetic variation of the RASGRF1 regulatory region affects human hippocampus-dependent memory  

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Full Text Available The guanine nucleotide exchange factor RASGRF1 is an important regulator of intracellular signaling and neural plasticity in the brain. RASGRF1-deficient mice exhibit a complex phenotype with learning deficits and ocular abnormalities. Also in humans, a genome-wide association study has identified the single nucleotide polymorphism (SNP rs8027411 in the putative transcription regulatory region of RASGRF1 as a risk variant of myopia. Here we aimed to assess whether, in line with the RASGRF1 knockout mouse phenotype, rs8027411 might also be associated with human memory function. We performed computer-based neuropsychological learning experiments in two independent cohorts of young, healthy participants. Tests included the Verbal Learning and Memory Test (VLMT and the logical memory section of the Wechsler Memory Scale (WMS. Two sub-cohorts additionally participated in functional magnetic resonance imaging (fMRI studies of hippocampus function. 119 participants performed a novelty encoding task that had previously been shown to engage the hippocampus, and 63 subjects participated in a reward-related memory encoding study. RASGRF1 rs8027411 genotype was indeed associated with memory performance in an allele dosage-dependent manner, with carriers of the T allele (i.e. the myopia risk allele showing better memory performance in the early encoding phase of the VLMT and in the recall phase of the WMS logical memory section. In fMRI, T allele carriers exhibited increased hippocampal activation during presentation of novel images and during encoding of pictures associated with monetary reward. Taken together, our results provide evidence for a role of the RASGRF1 gene locus in hippocampus-dependent memory and, along with the previous association with myopia, point towards pleitropic effects of RASGRF1 genetic variations on complex neural function in humans.

Björn H Schott

2014-04-01

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A transcription factor-binding domain of the coactivator CBP is essential for long-term memory and the expression of specific target genes  

OpenAIRE

Transcriptional activation is a key process required for long-term memory formation. Recently, the transcriptional coactivator CREB-binding protein (CBP) was shown to be critical for hippocampus-dependent long-term memory and hippocampal synaptic plasticity. As a coactivator with intrinsic histone acetyltransferase activity, CBP interacts with numerous transcription factors and contains multiple functional domains. Currently, it is not known which transcription factor-binding domain of CBP is...

Wood, Marcelo A.; Attner, Michelle A.; Oliveira, Ana M. M.; Brindle, Paul K.; Abel, Ted

2006-01-01

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Long-Term Memory Prediction Using Affine Motion Compensation  

OpenAIRE

Long-term memory prediction extends motion compensation from the previous frame to several past frames with the result of increased coding efficiency. We demonstrate that combining long-term memory prediction with affine motion compensation leads to further coding gains. For that, various affine motion parameter sets are estimated between frames in the long-term memory buffer and the current frame. Motion compensation is conducted using standard block matching in the multiple reference frame ...

Wiegand, T.; Steinbach, E.; Girod, B.

1999-01-01

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"Gadd45b" Knockout Mice Exhibit Selective Deficits in Hippocampus-Dependent Long-Term Memory  

Science.gov (United States)

Growth arrest and DNA damage-inducible [beta] ("Gadd45b") has been shown to be involved in DNA demethylation and may be important for cognitive processes. "Gadd45b" is abnormally expressed in subjects with autism and psychosis, two disorders associated with cognitive deficits. Furthermore, several high-throughput screens have identified "Gadd45b"…

Leach, Prescott T.; Poplawski, Shane G.; Kenney, Justin W.; Hoffman, Barbara; Liebermann, Dan A.; Abel, Ted; Gould, Thomas J.

2012-01-01

20

The role of basolateral amygdala adrenergic receptors in hippocampus dependent spatial memory in rat  

Directory of Open Access Journals (Sweden)

Full Text Available Background and the purpose of the study: There are extensive evidences indicating that the noradrenergic system of the basolateral nucleus of the amygdala (BLA is involved in memory processes. The present study investigated the role of the BLA adrenergic receptors (ARs in hippocampus dependent spatial memory in place avoidance task in male rat. Material and Methods: Long Evans rats (n=150 were trained to avoid footshock in a 60° segment while foraging for scattered food on a circular (80-cm diameter arena. The rats were injected bilaterally in the BLA specific ARS (Adrenergic receptors agonist norepinephrine (NE, 0.5 and 1 µg/µl and specific ?-ARs antagonist propranolol (PRO, 0.5 and 1 µg/µl before acquisition, after training or before retrieval of the place avoidance task. Control rats received vehicle at the same volume. The learning in a single 30-min session was assessed 24h later by a 30-min extinction trial in which the time to first entrance and the number of entrances to the shocked area measured the avoidance memory. Results: Acquisition and consolidation were enhanced and impaired significantly by NE and PRO when the drugs were injected 10 min before or immediately after training, respectively. In contrast, neither NE nor PRO influenced animal performances when injected before retention testing. Conclusion: Findings of this study indicates that adrenergic system of the BLA plays an important role in regulation of memory storage and show further evidences for the opinion that the BLA plays an important role in integrating hormonal and neurotransmitter influences on memory storage.

Vafaei A.L.

2008-03-01

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Item-location binding in working memory: is it hippocampus-dependent?  

Science.gov (United States)

A general consensus is emerging that the hippocampus has an important and active role in the creation of new long-term memory representations of associations or bindings between elements. However, it is less clear whether this contribution can be extended to the creation of temporary bound representations in working memory, involving the retention of small numbers of items over short delays. We examined this by administering a series of recognition and recall tests of working memory for colour-location binding and object-location binding to a patient with highly selective hippocampal damage (Jon), and groups of control participants. Jon achieved high levels of accuracy in all working memory tests of recognition and recall binding across retention intervals of up to 10s. In contrast, Jon performed at chance on an unexpected delayed test of the same object-location binding information. These findings indicate a clear dissociation between working memory and long-term memory, with no evidence for a critical hippocampal contribution to item-location binding in working memory. PMID:24784006

Allen, Richard J; Vargha-Khadem, Faraneh; Baddeley, Alan D

2014-07-01

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Hypocretin/orexin neurons contribute to hippocampus-dependent social memory and synaptic plasticity in mice.  

Science.gov (United States)

Hypocretin/orexin (Hcrt)-producing neurons in the lateral hypothalamus project throughout the brain, including to the hippocampus, where Hcrt receptors are widely expressed. Hcrt neurons activate these targets to orchestrate global arousal state, wake-sleep architecture, energy homeostasis, stress adaptation, and reward behaviors. Recently, Hcrt has been implicated in cognitive functions and social interaction. In the present study, we tested the hypothesis that Hcrt neurons are critical to social interaction, particularly social memory, using neurobehavioral assessment and electrophysiological approaches. The validated "two-enclosure homecage test" devices and procedure were used to test sociability, preference for social novelty (social novelty), and recognition memory. A conventional direct contact social test was conducted to corroborate the findings. We found that adult orexin/ataxin-3-transgenic (AT) mice, in which Hcrt neurons degenerate by 3 months of age, displayed normal sociability and social novelty with respect to their wild-type littermates. However, AT mice displayed deficits in long-term social memory. Nasal administration of exogenous Hcrt-1 restored social memory to an extent in AT mice. Hippocampal slices taken from AT mice exhibited decreases in degree of paired-pulse facilitation and magnitude of long-term potentiation, despite displaying normal basal synaptic neurotransmission in the CA1 area compared to wild-type hippocampal slices. AT hippocampi had lower levels of phosphorylated cAMP response element-binding protein (pCREB), an activity-dependent transcription factor important for synaptic plasticity and long-term memory storage. Our studies demonstrate that Hcrt neurons play an important role in the consolidation of social recognition memory, at least in part through enhancements of hippocampal synaptic plasticity and cAMP response element-binding protein phosphorylation. PMID:23516292

Yang, Liya; Zou, Bende; Xiong, Xiaoxing; Pascual, Conrado; Xie, James; Malik, Adam; Xie, Julian; Sakurai, Takeshi; Xie, Xinmin Simon

2013-03-20

23

Developmental Dyslexia and Explicit Long-Term Memory  

Science.gov (United States)

The reduced verbal long-term memory capacities often reported in dyslexics are generally interpreted as a consequence of their deficit in phonological coding. The present study was aimed at evaluating whether the learning deficit exhibited by dyslexics was restricted only to the verbal component of the long-term memory abilities or also involved…

Menghini, Deny; Carlesimo, Giovanni Augusto; Marotta, Luigi; Finzi, Alessandra; Vicari, Stefano

2010-01-01

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Nuclear protein phosphatase-1: an epigenetic regulator of fear memory and amygdala long-term potentiation.  

Science.gov (United States)

Complex brain diseases and neurological disorders in human generally result from the disturbance of multiple genes and signaling pathways. These disturbances may derive from mutations, deletions, translocations or rearrangements of specific gene(s). However, over the past years, it has become clear that such disturbances may also derive from alterations in the epigenome affecting several genes simultaneously. Our work recently demonstrated that epigenetic mechanisms in the adult brain are in part regulated by protein phosphatase 1 (PP1), a protein Ser/Thr phosphatase that negatively regulates hippocampus-dependent long-term memory (LTM) and synaptic plasticity. PP1 is abundant in brain structures involved in emotional processing like the amygdala, it may therefore be involved in the regulation of fear memory, a form of memory related to post-traumatic stress disorder (PTSD) in human. Here, we demonstrate that PP1 is a molecular suppressor of fear memory and synaptic plasticity in the amygdala that can control chromatin remodeling in neurons. We show that the selective inhibition of the nuclear pool of PP1 in amygdala neurons significantly alters posttranslational modifications (PTMs) of histones and the expression of several memory-associated genes. These alterations correlate with enhanced fear memory, and with an increase in long-term potentiation (LTP) that is transcription-dependent. Our results underscore the importance of nuclear PP1 in the amygdala as an epigenetic regulator of emotional memory, and the relevance of protein phosphatases as potential targets for therapeutic treatment of brain disorders like PTSD. PMID:21093547

Koshibu, K; Gräff, J; Mansuy, I M

2011-01-26

25

Thyroid receptor ? involvement in the effects of acute nicotine on hippocampus-dependent memory.  

Science.gov (United States)

Cigarette smoking is common despite adverse health effects. Nicotine's effects on learning may contribute to addiction by enhancing drug-context associations. Effects of nicotine on learning could be direct or could occur by altering systems that modulate cognition. Because thyroid signaling can alter cognition and nicotine/smoking may change thyroid function, nicotine could affect learning through changes in thyroid signaling. These studies investigate the functional contributions of thyroid receptor (TR) subtypes ? and ?1 to nicotine-enhanced learning and characterize the effects of acute nicotine and learning on thyroid hormone levels. We conducted a high throughput screen of transcription factor activity to identify novel targets that may contribute to the effects of nicotine on learning. Based on these results, which showed that combined nicotine and learning uniquely acted to increase TR activation, we identified TRs as potential targets of nicotine. Further analyses were conducted to determine the individual and combined effects of nicotine and learning on thyroid hormone levels, but no changes were seen. Next, to determine the role of TR? and TR?1 in the effects of nicotine on learning, mice lacking the TR? or TR?1 gene and wildtype littermates were administered acute nicotine prior to fear conditioning. Nicotine enhanced contextual fear conditioning in TR?1 knockout mice and wildtypes from both lines but TR? knockout mice did not show nicotine-enhanced learning. This finding supports involvement of TR? signaling in the effect of acute nicotine on hippocampus-dependent memory. Acute nicotine enhances learning and these effects may involve processes regulated by the transcription factor TR?. PMID:25666034

Leach, Prescott T; Kenney, Justin W; Connor, David A; Gould, Thomas J

2015-06-01

26

Enhanced long-term and impaired short-term spatial memory in GluA1 AMPA receptor subunit knockout mice: Evidence for a dual-process memory model  

OpenAIRE

The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity of GluA1-dependent synaptic plasticity for short-term memory of recently visited places, but not for the ability to form long-term associations betwee...

Sanderson, Dj; Good, Ma; Skelton, K.; Sprengel, R.; Seeburg, Ph; Rawlins, Jn; Bannerman, Dm

2009-01-01

27

Long-term memory impairment in patients with focal epilepsy.  

Science.gov (United States)

In temporal lobe epilepsy, long-term memory disturbance starts early in life mainly affecting declarative memory. Primary impairment of episodic memory often results in reduced semantic and autobiographic memory. Neuropsychological performance predicts academic achievement and everyday life functioning while subjective memory complaints are highly correlated with depression. Memory impairment is also influenced by initial brain damage, developmental retardation and dynamic factors (e.g., seizure frequency, medication). Damage of functional tissue, low mental reserve capacity, and poor seizure outcome increase the risk for postsurgical memory impairment whereas functional release due to seizure freedom counteracts negative impact. Preliminary findings indicate that postsurgical training improves memory deficits and encourage further research. PMID:18047597

Hoppe, Christian; Elger, Christian E; Helmstaedter, Christoph

2007-01-01

28

Merging of long-term memories in an insect.  

Science.gov (United States)

Research on comparative cognition has largely focused on successes and failures of animals to solve certain cognitive tasks, but in humans, memory errors can be more complex than simple failures to retrieve information [1, 2]. The existence of various types of "false memories," in which individuals remember events that they have never actually encountered, are now well established in humans [3, 4]. We hypothesize that such systematic memory errors may be widespread in animals whose natural lifestyle involves the processing and recollection of memories for multiple stimuli [5]. We predict that memory traces for various stimuli may "merge," such that features acquired in distinct bouts of training are combined in an animal's mind, so that stimuli that have never been viewed before, but are a combination of the features presented in training, may be chosen during recall. We tested this using bumblebees, Bombus terrestris. When individuals were first trained to a solid single-colored stimulus followed by a black and white (b/w)-patterned stimulus, a subsequent preference for the last entrained stimulus was found in both short-term- and long-term-memory tests. However, when bees were first trained to b/w-patterned stimuli followed by solid single-colored stimuli and were tested in long-term-memory tests 1 or 3 days later, they only initially preferred the most recently rewarded stimulus, and then switched their preference to stimuli that combined features from the previous color and pattern stimuli. The observed merging of long-term memories is thus similar to the memory conjunction error found in humans [6]. PMID:25728692

Hunt, Kathryn L; Chittka, Lars

2015-03-16

29

A quantitative proteomic analysis of long-term memory  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Memory is the ability to store, retain, and later retrieve learned information. Long-term memory (LTM formation requires: DNA transcription, RNA translation, and the trafficking of newly synthesized proteins. Several components of these processes have already been identified. However, due to the complexity of the memory formation process, there likely remain many yet to be identified proteins involved in memory formation and persistence. Results Here we use a quantitative proteomic method to identify novel memory-associated proteins in neural tissue taken from animals that were trained in vivo to form a long-term memory. We identified 8 proteins that were significantly up-regulated, and 13 that were significantly down-regulated in the LTM trained animals as compared to two different control groups. In addition we found 19 proteins unique to the trained animals, and 12 unique proteins found only in the control animals. Conclusions These results both confirm the involvement of previously identified memory proteins such as: protein kinase C (PKC, adenylate cyclase (AC, and proteins in the mitogen-activated protein kinase (MAPK pathway. In addition these results provide novel protein candidates (e.g. UHRF1 binding protein on which to base future studies.

Rosenegger David

2010-03-01

30

Long-Term Memory Search across the Visual Brain  

OpenAIRE

Signal transmission from the human retina to visual cortex and connectivity of visual brain areas are relatively well understood. How specific visual perceptions transform into corresponding long-term memories remains unknown. Here, I will review recent Blood Oxygenation Level-Dependent functional Magnetic Resonance Imaging (BOLD fMRI) in humans together with molecular biology studies (animal models) aiming to understand how the retinal image gets transformed into so-called visual (retinotrop...

Fedurco, Milan

2012-01-01

31

Genetic Disruption of the Core Circadian Clock Impairs Hippocampus-Dependent Memory  

Science.gov (United States)

Perturbing the circadian system by electrolytically lesioning the suprachiasmatic nucleus (SCN) or varying the environmental light:dark schedule impairs memory, suggesting that memory depends on the circadian system. We used a genetic approach to evaluate the role of the molecular clock in memory. Bmal1[superscript -/-] mice, which are arrhythmic…

Wardlaw, Sarah M.; Phan, Trongha X.; Saraf, Amit; Chen, Xuanmao; Storm, Daniel R.

2014-01-01

32

Working memory, long-term memory and language processing : issues and future directions  

OpenAIRE

We examined different views of the relationships between working memory, long-term memory and language processing : working memory considered as a gateway between sensory input and long-term memory or rather as a workspace; working memory considered as not strictly tied to any particular cognitive system (and consequently viewed as separated from the language system) or rather as drawing on the operation and storage capacities of a subset of components involved in language processing. It is a...

Collette, Fabienne; Linden, Martial; Poncelet, Martine

2000-01-01

33

Wnt Signaling Is Required for Long-Term Memory Formation  

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Full Text Available Wnt signaling regulates synaptic plasticity and neurogenesis in the adult nervous system, suggesting a potential role in behavioral processes. Here, we probed the requirement for Wnt signaling during olfactory memory formation in Drosophila using an inducible RNAi approach. Interfering with ?-catenin expression in adult mushroom body neurons specifically impaired long-term memory (LTM without altering short-term memory. The impairment was reversible, being rescued by expression of a wild-type ?-catenin transgene, and correlated with disruption of a cellular LTM trace. Inhibition of wingless, a Wnt ligand, and arrow, a Wnt coreceptor, also impaired LTM. Wingless expression in wild-type flies was transiently elevated in the brain after LTM conditioning. Thus, inhibiting three key components of the Wnt signaling pathway in adult mushroom bodies impairs LTM, indicating that this pathway mechanistically underlies this specific form of memory.

Ying Tan

2013-09-01

34

Persistent deficits in hippocampal synaptic plasticity accompany losses of hippocampus-dependent memory in a rodent model of psychosis  

Directory of Open Access Journals (Sweden)

Full Text Available Irreversible N-methyl-D-aspartate receptor (NMDAR antagonism is known to provoke symptoms of psychosis and schizophrenia in healthy humans. NMDAR hypofunction is believed to play a central role in the pathophysiology of both disorders and in an animal model of psychosis, that is based on irreversible antagonism of NMDARs, pronounced deficits in hippocampal synaptic plasticity have been reported shortly after antagonist treatment. Here, we examined the long-term consequences for long-term potentiation (LTP of a single acute treatment with an irreversible antagonist and investigated whether deficits are associated with memory impairments. The ability to express long-term potentiation (LTP at the perforant pathway – dentate gyrus synapse, as well as object recognition memory was assessed 1, 2, 3 and 4 weeks after a single -treatment of the antagonist, MK801. Here, LTP in freely behaving rats was significantly impaired at all time-points compared to control LTP before treatment. Object recognition memory was also significantly poorer in MK801-treated compared to vehicle-treated animals for several weeks after treatment. Histological analysis revealed no changes in brain tissue. Taken together, these data support that acute treatment with an irreversible NMDAR antagonist persistently impairs hippocampal functioning on behavioral, as well as synaptic levels. The long-term deficits in synaptic plasticity may underlie the cognitive impairments that are associated with schizophrenia-spectrum disorders.

DeniseManahan-Vaughan

2013-03-01

35

Long-term memory of heterospecific vocalizations by African lions  

Science.gov (United States)

Animals that use and evaluate long-distance signals have the potential to glean valuable information about others in their environment via eavesdropping. In those areas where they coexist, African lions (Panthera leo) are a significant eavesdropper on spotted hyenas (Crocuta crocuta), often using hyena vocalizations to locate and scavenge from hyena kills. This relationship was used to test African lions' long-term memory of the vocalizations of spotted hyenas via playback experiments. Hyena whoops and a control sound (Canis lupus howls) were played to three populations of lions in South Africa: (1) lions with past experience of spotted hyenas; (2) lions with current experience; and (3) lions with no experience. The results strongly suggest that lions have the cognitive ability to remember the vocalizations of spotted hyenas even after 10 years with no contact of any kind with them. Such long-term memory of heterospecific vocalizations may be widespread in species that gain fitness benefits from eavesdropping on others, but where such species are sympatric and often interact it may pass unrecognized as short-term memory instead.

Grinnell, Jon; van Dyk, Gus; Slotow, Rob

2005-09-01

36

Working Memory, Long-Term Memory, and Medial Temporal Lobe Function  

Science.gov (United States)

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance…

Jeneson, Annette; Squire, Larry R.

2012-01-01

37

Examining the long-term stability of overgeneral autobiographical memory.  

Science.gov (United States)

Overgeneral autobiographical memory (OGM) is a proposed trait-marker for vulnerability to depression, but relatively little work has examined its long-term stability. This study investigated the stability of OGM over several years in 271 late adolescents and young adults participating in a larger longitudinal study of risk for emotional disorders. The Autobiographical Memory Test (AMT) was administered twice, with test-retest intervals ranging from approximately 3 to 6 years. There was evidence of significant but modest stability in OGM over several years. Specifically, Spearman rank correlations (?s) between the proportions of specific and categoric memories generated on the two AMTs were .31 and .32, respectively. We did not find evidence that the stability of OGM was moderated by the length of the test-retest interval. Furthermore, the stability coefficients for OGM for individuals with and without a lifetime history of major depressive disorder (MDD) were relatively similar in magnitude and not significantly different from one another (?s=.34 and .42 for the proportions of specific and categoric memories for those with a history of MDD; ?s=.31 for both the proportions of specific and categoric memories for those without a history of MDD). Implications for the conceptualisation of OGM are discussed. PMID:23439226

Sumner, Jennifer A; Mineka, Susan; Zinbarg, Richard E; Craske, Michelle G; Vrshek-Schallhorn, Suzanne; Epstein, Alyssa

2014-01-01

38

Effects of sleep deprivation and aging on long-term and remote memory in mice.  

Science.gov (United States)

Sleep deprivation (SD) following hippocampus-dependent learning in young mice impairs memory when tested the following day. Here, we examined the effects of SD on remote memory in both young and aged mice. In young mice, we found that memory is still impaired 1 mo after training. SD also impaired memory in aged mice 1 d after training, but, by a month after training, sleep-deprived and control aged animals performed similarly, primarily due to remote memory decay in the control aged animals. Gene expression analysis supported the finding that SD has similar effects on the hippocampus in young and aged mice. PMID:25776037

Vecsey, Christopher G; Park, Alan J; Khatib, Nora; Abel, Ted

2015-04-01

39

Long-term memory of individual identity in ant queens  

DEFF Research Database (Denmark)

Remembering individual identities is part of our own everyday social life. Surprisingly, this ability has recently been shown in two social insects. While paper wasps recognize each other individually through their facial markings, the ant, Pachycondyla villosa, uses chemical cues. In both species, individual recognition is adaptive since it facilitates the maintenance of stable dominance hierarchies among individuals, and thus reduces the cost of conflict within these small societies. Here, we investigated individual recognition in Pachycondyla ants by quantifying the level of aggression between pairs of familiar or unfamiliar queens over time. We show that unrelated founding queens of P. villosa and Pachycondyla inversa store information on the individual identity of other queens and can retrieve it from memory after 24h of separation. Thus, we have documented for the first time that long-term memory of individual identity is present and functional in ants. This novel finding represents an advance in our understanding of the mechanism determining the evolution of cooperation among unrelated individuals.

Dreier, Stéphanie Agnès Jeanine; Van Zweden, Jelle Stijn

2007-01-01

40

Working memory, long-term memory, and medial temporal lobe function  

OpenAIRE

Early studies of memory-impaired patients with medial temporal lobe (MTL) damage led to the view that the hippocampus and related MTL structures are involved in the formation of long-term memory and that immediate memory and working memory are independent of these structures. This traditional idea has recently been revisited. Impaired performance in patients with MTL lesions on tasks with short retention intervals, or no retention interval, and neuroimaging findings with similar tasks have be...

Jeneson, Annette; Squire, Larry R.

2012-01-01

41

Subregion-specific p300 conditional knock-out mice exhibit long-term memory impairments  

OpenAIRE

Histone acetylation plays a critical role during long-term memory formation. Several studies have demonstrated that the histone acetyltransferase (HAT) CBP is required during long-term memory formation, but the involvement of other HAT proteins has not been extensively investigated. The HATs CBP and p300 have at least 400 described interacting proteins including transcription factors known to play a role in long-term memory formation. Thus, CBP and p300 constitute likely candidates for transc...

Oliveira, Ana M. M.; Este?vez, Marcel A.; Hawk, Joshua D.; Grimes, Shannon; Brindle, Paul K.; Abel, Ted

2011-01-01

42

Learning-facilitated long-term depression and long-term potentiation at mossy fiber—CA3 synapses requires activation of ?-adrenergic receptors  

OpenAIRE

Learning-facilitated plasticity refers to hippocampal synaptic plasticity that is facilitated by novel spatial learning events. Both long-term potentiation (LTP) and long-term depression (LTD) are facilitated by novel hippocampus-dependent learning. This has important ramifications for our understanding of how the hippocampus encodes memory. One structure that is rarely studied in vivo, but is believed to be crucially important for working and long-term memory processing is the hippocampal CA...

Hagena, Hardy; Manahan-vaughan, Denise

2012-01-01

43

Individual differences in emotional memory: adult attachment and long-term memory for child sexual abuse.  

Science.gov (United States)

In the present study, attachment-related differences in long-term memory for a highly emotional life event, child sexual abuse (CSA), were investigated. Participants were 102 documented CSA victims whose cases were referred for prosecution approximately 14 years earlier. Consistent with the proposal that avoidant individuals defensively regulate the processing of potentially distressing information (Bowlby, 1980), attachment avoidance was negatively associated with memory for particularly severe CSA incidents. This finding was not mediated by the extent to which participants reported talking about the abuse after it occurred, although post abuse discussion did enhance long-term memory. In addition, accuracy was positively associated with maternal support following the abuse and extent of CSA-related legal involvement. Attachment anxiety was unrelated to memory accuracy, regardless of abuse severity. Implications of the findings for theories of avoidant defensive strategies and emotional memory are discussed. PMID:16207772

Edelstein, Robin S; Ghetti, Simona; Quas, Jodi A; Goodman, Gail S; Alexander, Kristen Weede; Redlich, Allison D; Cordón, Ingrid M

2005-11-01

44

The Neural Substrates of Recognition Memory for Verbal Information: Spanning the Divide between Short- and Long-term Memory  

OpenAIRE

One of the classic categorical divisions in the history of memory research is that between short-term and long-term memory. Indeed, because memory for the immediate past (a few seconds) and memory for the relatively more remote past (several seconds and beyond) are assumed to rely on distinct neural systems, more often than not, memory research has focused either on short- (or “working memory”) or on long-term memory. Using an auditory–verbal continuous recognition paradigm designed for...

Buchsbaum, Bradley R.; Padmanabhan, Aarthi; Berman, Karen Faith

2010-01-01

45

Transient impairment of hippocampus-dependent learning and memory in relatively low-dose of acute radiation syndrome is associated with inhibition of hippocampal neurogenesis  

International Nuclear Information System (INIS)

Neurogenesis in the adult hippocampus, which occurs constitutively, is vulnerable to ionizing radiation. In the relatively low-dose exposure of acute radiation syndrome (ARS), the change in the adult hippocampal function is poorly understood. This study analyzed the changes in apoptotic cell death and neurogenesis in the DGs of hippocampi from adult ICR mice with single whole-body gamma-irradiation using the TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method and immunohistochemical markers of neurogenesis, Ki-67 and doublecortin (DCX). In addition, the hippocampus-dependent learning and memory tasks after single whole-body gamma-irradiation were examined in order to evaluate the hippocampus-related behavioral dysfunction in the relatively low-dose exposure of ARS. The number of TUNEL-positive apoptotic nuclei in the dentate gyrus (DG) was increased 6-12 h after acute gamma-irradiation (a single dose of 0.5 to 4 Gy). In contrast, the number of Ki-67- and DCX-positive cells began to decrease significantly 6 h postirradiation, reaching its lowest level 24 h after irradiation. The level of Ki-67 and DCX immunoreactivity decreased in a dose-dependent manner within the range of irradiation applied (0-4 Gy). In passive avoidance and object recognition memory test, the mice trained 1 day after acute irradiation (2 Gy) showed significant memory deficits, compared with the sham controls. In conclusion, the pattern of the hippocampus-dependent memory dysfunction is consispus-dependent memory dysfunction is consistent with the change in neurogenesis after acute irradiation. It is suggested that a relatively low dose of ARS in adult ICR mice is sufficiently detrimental to interrupt the functioning of the hippocampus, including learning and memory, possibly through the inhibition of neurogenesis. (author)

46

Evidence for long-term memory in sea level  

Science.gov (United States)

Detection and attribution of anthropogenic climate change signals in sea level rise (SLR) has experienced considerable attention during the last decades. Here we provide evidence that superimposed on any possible anthropogenic trend there is a significant amount of natural decadal and multidecadal variability. Using a set of 60 centennial tide gauge records and an ocean reanalysis, we find that sea levels exhibit long-term correlations on time scales up to several decades that are independent of any systematic rise. A large fraction of this long-term variability is related to the steric component of sea level, but we also find long-term correlations in current estimates of mass loss from glaciers and ice caps. These findings suggest that (i) recent attempts to detect a significant acceleration in regional SLR might underestimate the impact of natural variability and (ii) any future regional SLR threshold might be exceeded earlier/later than from anthropogenic change alone.

Dangendorf, Sönke; Rybski, Diego; Mudersbach, Christoph; Müller, Alfred; Kaufmann, Edgar; Zorita, Eduardo; Jensen, Jürgen

2014-08-01

47

The Histone Deacetylase HDAC4 Regulates Long-Term Memory in Drosophila  

OpenAIRE

A growing body of research indicates that pharmacological inhibition of histone deacetylases (HDACs) correlates with enhancement of long-term memory and current research is concentrated on determining the roles that individual HDACs play in cognitive function. Here, we investigate the role of HDAC4 in long-term memory formation in Drosophila. We show that overexpression of HDAC4 in the adult mushroom body, an important structure for memory formation, resulted in a specific impairment in long-...

Fitzsimons, Helen L.; Schwartz, Silvia; Given, Fiona M.; Scott, Maxwell J.

2013-01-01

48

SPECIFIC LONG-TERM MEMORY TRACES IN PRIMARY AUDITORY CORTEX  

OpenAIRE

Learning and memory involve the storage of specific sensory experiences. However, until recently the idea that the primary sensory cortices could store specific memory traces had received little attention. Converging evidence obtained using techniques from sensory physiology and the neurobiology of learning and memory supports the idea that the primary auditory cortex acquires and retains specific memory traces about the behavioural significance of selected sounds. The cholinergic system of t...

Weinberger, Norman M.

2004-01-01

49

Distinct dopamine neurons mediate reward signals for short- and long-term memories.  

Science.gov (United States)

Drosophila melanogaster can acquire a stable appetitive olfactory memory when the presentation of a sugar reward and an odor are paired. However, the neuronal mechanisms by which a single training induces long-term memory are poorly understood. Here we show that two distinct subsets of dopamine neurons in the fly brain signal reward for short-term (STM) and long-term memories (LTM). One subset induces memory that decays within several hours, whereas the other induces memory that gradually develops after training. They convey reward signals to spatially segregated synaptic domains of the mushroom body (MB), a potential site for convergence. Furthermore, we identified a single type of dopamine neuron that conveys the reward signal to restricted subdomains of the mushroom body lobes and induces long-term memory. Constant appetitive memory retention after a single training session thus comprises two memory components triggered by distinct dopamine neurons. PMID:25548178

Yamagata, Nobuhiro; Ichinose, Toshiharu; Aso, Yoshinori; Plaçais, Pierre-Yves; Friedrich, Anja B; Sima, Richard J; Preat, Thomas; Rubin, Gerald M; Tanimoto, Hiromu

2015-01-13

50

Long-term Memory and Volatility Clustering in Daily and High-frequency Price Changes  

CERN Document Server

We study the long-term memory in diverse stock market indices and foreign exchange rates using the Detrended Fluctuation Analysis(DFA). For all daily and high-frequency market data studied, no significant long-term memory property is detected in the return series, while a strong long-term memory property is found in the volatility time series. The possible causes of the long-term memory property are investigated using the return data filtered by the AR(1) model, reflecting the short-term memory property, and the GARCH(1,1) model, reflecting the volatility clustering property, respectively. Notably, we found that the memory effect in the AR(1) filtered return and volatility time series remains unchanged, while the long-term memory property either disappeared or diminished significantly in the volatility series of the GARCH(1,1) filtered data. We also found that in the high-frequency data the long-term memory property may be generated by the volatility clustering as well as higher autocorrelation. Our results i...

Oh, G J; Um, C J; Kim, Seunghwann; Oh, GabJin; Um, Cheol-Jun

2006-01-01

51

Zeta inhibitory peptide (ZIP) erases long-term memories in a cockroach.  

Science.gov (United States)

Recent efforts to identify the molecules that are involved in the maintenance of long-term memories in mammals have focused attention on atypical isoforms of protein kinase C (PKC). Inhibition of these kinases by either the general PKC inhibitor, chelerythrine, or the more specific inhibitor, zeta inhibitory peptide (ZIP), can abolish both long-term potentiation in the hippocampus and as well as spatial, fear, appetitive, and sensorimotor memories. These inhibitors can also abolish long-term facilitation and long-term sensitization in the mollusk Aplysia californica. We have extended these results to an insect, the cockroach Leucophaea maderae. We show that systemic injections of either chelerythrine or ZIP erase long-term olfactory memories in the cockroach, but have no effect on memory acquisition during conditioning. We also show that inhibition of either protein kinase A (PKA) or protein synthesis can block memory acquisition but neither has an effect on the memory once it is formed. The results suggest that sustaining memories in insects requires the persistent activity of one or more isoforms of PKC and point to a strong evolutionary conservation of the molecular mechanisms that underlie the persistence of long-term memories in the central nervous system. PMID:25434819

Deng, Zhouheng; Lubinski, Alexander J; Page, Terry L

2015-02-01

52

Early calcium increase triggers the formation of olfactory long-term memory in honeybees  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Synaptic plasticity associated with an important wave of gene transcription and protein synthesis underlies long-term memory processes. Calcium (Ca2+ plays an important role in a variety of neuronal functions and indirect evidence suggests that it may be involved in synaptic plasticity and in the regulation of gene expression correlated to long-term memory formation. The aim of this study was to determine whether Ca2+ is necessary and sufficient for inducing long-term memory formation. A suitable model to address this question is the Pavlovian appetitive conditioning of the proboscis extension reflex in the honeybee Apis mellifera, in which animals learn to associate an odor with a sucrose reward. Results By modulating the intracellular Ca2+ concentration ([Ca2+]i in the brain, we show that: (i blocking [Ca2+]i increase during multiple-trial conditioning selectively impairs long-term memory performance; (ii conversely, increasing [Ca2+]i during single-trial conditioning triggers long-term memory formation; and finally, (iii as was the case for long-term memory produced by multiple-trial conditioning, enhancement of long-term memory performance induced by a [Ca2+]i increase depends on de novo protein synthesis. Conclusion Altogether our data suggest that during olfactory conditioning Ca2+ is both a necessary and a sufficient signal for the formation of protein-dependent long-term memory. Ca2+ therefore appears to act as a switch between short- and long-term storage of learned information.

Matsumoto Yukihisa

2009-06-01

53

Lateral Habenula determines long-term storage of aversive memories.  

Directory of Open Access Journals (Sweden)

Full Text Available The Lateral Habenula (LHb is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA. We found that LHb inactivation during IA training does not disrupt memory when assessed 24 hours after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.

Micol Tomaiuolo

2014-05-01

54

The Neural Substrates of Recognition Memory for Verbal Information: Spanning the Divide between Short- and Long-Term Memory  

Science.gov (United States)

One of the classic categorical divisions in the history of memory research is that between short-term and long-term memory. Indeed, because memory for the immediate past (a few seconds) and memory for the relatively more remote past (several seconds and beyond) are assumed to rely on distinct neural systems, more often than not, memory research…

Buchsbaum, Bradley R.; Padmanabhan, Aarthi; Berman, Karen Faith

2011-01-01

55

GABA-Mediated Presynaptic Inhibition Is Required for Precision of Long-Term Memory  

Science.gov (United States)

Though much attention has been given to the neural structures that underlie the long-term consolidation of contextual memories, little is known about the mechanisms responsible for the maintenance of memory precision. Here, we demonstrate a rapid time-dependent decline in memory precision in GABA [subscript B(1a)] receptor knockout mice. First, we…

Cullen, Patrick K.; Dulka, Brooke N.; Ortiz, Samantha; Riccio, David C.; Jasnow, Aaron M.

2014-01-01

56

Long-term memory effects on verbal short-term memory : a replication study  

OpenAIRE

The influence of lexico-semantic language representations stored in long-term memory (LTM) on short-term memory (STM) performance has been studied extensively in adults. However, there are relatively few data on lexico-semantic LTM effects on STM in children. On the other hand, the influence of phonological LTM effects on STM has been studied more extensively in children than in adults. In this study, we explored whether these different LTM effects on verbal STM could be replicated in both ad...

Majerus, Steve; Linden, Martial

2003-01-01

57

Insulin signaling is acutely required for long-term memory in Drosophila  

Science.gov (United States)

Memory formation has been shown recently to be dependent on energy status in Drosophila. A well-established energy sensor is the insulin signaling (InS) pathway. Previous studies in various animal models including human have revealed the role of insulin levels in short-term memory but its role in long-term memory remains less clear. We therefore investigated genetically the spatial and temporal role of InS using the olfactory learning and long-term memory model in Drosophila. We found that InS is involved in both learning and memory. InS in the mushroom body is required for learning and long-term memory whereas long-term memory specifically is impaired after InS signaling disruption in the ellipsoid body, where it regulates the level of p70s6k, a downstream target of InS and a marker of protein synthesis. Finally, we show also that InS is acutely required for long-term memory formation in adult flies. PMID:25805973

Chambers, Daniel B.; Androschuk, Alaura; Rosenfelt, Cory; Langer, Steven; Harding, Mark; Bolduc, Francois V.

2015-01-01

58

Two Waves of Transcription Are Required for Long-Term Memory in the Honeybee  

Science.gov (United States)

Storage of information into long-term memory (LTM) usually requires at least two waves of transcription in many species. However, there is no clear evidence of this phenomenon in insects, which are influential models for memory studies. We measured retention in honeybees after injecting a transcription inhibitor at different times before and after…

Lefer, Damien; Perisse, Emmanuel; Hourcade, Benoit; Sandoz, JeanChristophe; Devaud, Jean-Marc

2013-01-01

59

The neuroimaging of long-term memory encoding processes.  

Science.gov (United States)

There needs to be more crosstalk between the lesion and functional neuroimaging memory literatures. This is illustrated by a discussion of episode and fact encoding. The lesion literature suggests several hypotheses about which brain regions underlie the storage of episode and fact information, which can be explored by functional neuroimaging. These hypotheses have been underexplored because neuroimaging studies of encoding have been insufficiently hypothesis-driven and have not controlled encoding-related processes sufficiently well to allow clear interpretations of results to be made. Nevertheless, there is good evidence that certain kinds of associative encoding and/or consolidation are sufficient to activate the medial temporal lobes, and preliminary evidence that some kinds of associative priming may reduce activation of this region. It remains to be proved that attentional orienting to certain kinds of novel information activates the medial temporal lobes. Evidence is growing that the HERA model, developed from neuroimaging rather than lesion data, requires modification and that frontal cortex encoding activations are probably caused by executive processes that are important in effortful memory processing. Neuroimaging studies allow the detection of encoding-related activations in previously unexpected brain regions (e.g. parietal lobes) and, in turn, these findings can be explored with lesion studies. PMID:10659090

Mayes, A R; Montaldi, D

1999-01-01

60

Enhanced Long-Term and Impaired Short-Term Spatial Memory in GluA1 AMPA Receptor Subunit Knockout Mice: Evidence for a Dual-Process Memory Model  

Science.gov (United States)

The GluA1 AMPA receptor subunit is a key mediator of hippocampal synaptic plasticity and is especially important for a rapidly-induced, short-lasting form of potentiation. GluA1 gene deletion impairs hippocampus-dependent, spatial working memory, but spares hippocampus-dependent spatial reference memory. These findings may reflect the necessity of…

Sanderson, David J.; Good, Mark A.; Skelton, Kathryn; Sprengel, Rolf; Seeburg, Peter H.; Rawlins, J. Nicholas P.; Bannerman, David M.

2009-01-01

61

What are the differences between long-term, short-term, and working memory?  

OpenAIRE

In the recent literature there has been considerable confusion about the three types of memory: long-term, short-term, and working memory. This chapter strives to reduce that confusion and makes up-to-date assessments of these types of memory. Long- and short-term memory could differ in two fundamental ways, with only short-term memory demonstrating (1) temporal decay and (2) chunk capacity limits. Both properties of short-term memory are still controversial but the current literature is rath...

Cowan, Nelson

2008-01-01

62

Retrieval from long-term memory reduces working memory representations for visual features and their bindings.  

Science.gov (United States)

The ability to remember feature bindings is an important measure of the ability to maintain objects in working memory (WM). In this study, we investigated whether both object- and feature-based representations are maintained in WM. Specifically, we tested the hypotheses that retaining a greater number of feature representations (i.e., both as individual features and bound representations) results in a more robust representation of individual features than of feature bindings, and that retrieving information from long-term memory (LTM) into WM would cause a greater disruption to feature bindings. In four experiments, we examined the effects of retrieving a word from LTM on shape and color-shape binding change detection performance. We found that binding changes were more difficult to detect than individual-feature changes overall, but that the cost of retrieving a word from LTM was the same for both individual-feature and binding changes. PMID:25301564

van Lamsweerde, Amanda E; Beck, Melissa R; Elliott, Emily M

2015-02-01

63

The amygdala's role in long-term declarative memory for gist and detail.  

Science.gov (United States)

In humans, the emotional nature of stimuli appears to have a complex influence on long-term declarative memory for those stimuli: Whereas emotion enhances memory for gist, it may suppress memory for detail. On the basis of prior studies, the authors hypothesized that the amygdala helps mediate the above 2 effects. Long-term memory for gist and for visual detail of aversive and neutral scenes was assessed in 20 subjects with unilateral amygdala damage and 1 rare subject with bilateral amygdala damage. Comparisons with 2 control groups (15 brain-damaged and 47 healthy) provided evidence that bilateral, but not unilateral, damage to the amygdala results in poorer memory for gist but superior memory for visual details. The pattern of findings provides preliminary support for the idea that the amygdala may help filter the encoding of relevant information from stimuli that signal threat or danger. PMID:11584931

Adolphs, R; Denburg, N L; Tranel, D

2001-10-01

64

Endogenous BDNF is required for long-term memory formation in the rat parietal cortex  

OpenAIRE

Information storage in the brain is a temporally graded process involving different memory phases as well as different structures in the mammalian brain. Cortical plasticity seems to be essential to store stable long-term memories, although little information is available at the moment regarding molecular and cellular events supporting memory consolidation in the neocortex. Brain-derived neurotrophic factor (BDNF) modulates both short-term synaptic function and activity-dependent synaptic pla...

Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Marti?n; Vianna, Monica R. M.; Izquierdo, Iva?n; Medina, Jorge H.

2005-01-01

65

Linking Working Memory and Long-Term Memory: A Computational Model of the Learning of New Words  

Science.gov (United States)

The nonword repetition (NWR) test has been shown to be a good predictor of children's vocabulary size. NWR performance has been explained using phonological working memory, which is seen as a critical component in the learning of new words. However, no detailed specification of the link between phonological working memory and long-term memory

Jones, Gary; Gobet, Fernand; Pine, Julian M.

2007-01-01

66

Modality-specific alpha modulations facilitate long-term memory encoding in the presence of distracters.  

Science.gov (United States)

It has been proposed that long-term memory encoding is not only dependent on engaging task-relevant regions but also on disengaging task-irrelevant regions. In particular, oscillatory alpha activity has been shown to be involved in shaping the functional architecture of the working brain because it reflects the functional disengagement of specific regions in attention and memory tasks. We here ask if such allocation of resources by alpha oscillations generalizes to long-term memory encoding in a cross-modal setting in which we acquired the ongoing brain activity using magnetoencephalography. Participants were asked to encode pictures while ignoring simultaneously presented words and vice versa. We quantified the brain activity during rehearsal reflecting subsequent memory in the different attention conditions. The key finding was that successful long-term memory encoding is reflected by alpha power decreases in the sensory region of the to-be-attended modality and increases in the sensory region of the to-be-ignored modality to suppress distraction during rehearsal period. Our results corroborate related findings from attention studies by demonstrating that alpha activity is also important for the allocation of resources during long-term memory encoding in the presence of distracters. PMID:25244116

Jiang, Haiteng; van Gerven, Marcel A J; Jensen, Ole

2015-03-01

67

Can we throw information out of visual working memory and does this leave informational residue in long-term memory?  

Directory of Open Access Journals (Sweden)

Full Text Available Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this proposal. However, given the infinite capacity of long-term memory, it is unclear whether throwing a representation out of visual working memory really removes its effects on memory entirely. In this paper we advocate for an approach that examines our ability to erase memory representations from working memory, as well as possible traces that those erased representations leave in long-term memory.

AshleighMonetteMaxcey

2014-04-01

68

Tree ring records capture long-term memory in climate systems  

Science.gov (United States)

Measuring tree rings is a mainstay technique for estimating ancient climatic conditions, with a tree's year-by-year growth reflecting changes in precipitation and temperature. In some cases, paleoclimatological records compiled from tree ring measurements can stretch for thousands of years. Based on recent research, climatologists have found that hydrological and other systems have long-term memory. Drawing on tree ring measurements compiled from across the continental United States, Bowers et al. sought to determine whether such long-term relationships are preserved in ring width measurements. The authors analyzed the Hurst parameter—a measure of long-term memory—of 697 different tree ring records that were collected from 10 tree species from locations across the United States. They found that though each tree species had a different mean value for its Hurst parameter, meaning that each species recorded long-term trends in the climate differently, they all fell within the range suggestive of their being able to properly represent long-term memory.

Schultz, Colin

2013-03-01

69

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats.  

Science.gov (United States)

General anesthetics are neurotoxic to neonatal rodents and non-human primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long-Evans rat pups were exposed to 1.8% isoflurane for 2?h on postnatal day (P) 7, or for 2?h each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life. PMID:23847588

Murphy, Kathy L; Baxter, Mark G

2013-01-01

70

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats  

Directory of Open Access Journals (Sweden)

Full Text Available General anesthetics are neurotoxic to neonatal rodents and nonhuman primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated with long-term cognitive impairments and whether the magnitude of impairments was greater than that resulting from a single exposure. Male or female Long-Evans rat pups were exposed to 1.8% isoflurane for 2 hours on postnatal day (P 7, or for 2 hours each on P7, P10, and P13. Testing in a spatial working memory task began on P91. Rats that were repeatedly exposed to isoflurane were impaired relative to controls in the spatial working memory task. Male rats that received a single exposure to isoflurane showed an unexpected facilitation in spatial memory performance. These results support the hypothesis that multiple neonatal exposures to general anesthesia are associated with greater long-term cognitive impairment than a single exposure. The findings are congruent with human epidemiological studies reporting long-term cognitive impairments following multiple but not single general anesthetics early in life.

MarkGBaxter

2013-07-01

71

SNAP-25 in hippocampal CA3 region is required for long-term memory formation  

International Nuclear Information System (INIS)

SNAP-25 is a synaptosomal protein of 25 kDa, a key component of synaptic vesicle-docking/fusion machinery, and plays a critical role in exocytosis and neurotransmitter release. We previously reported that SNAP-25 in the hippocampal CA1 region is involved in consolidation of contextual fear memory and water-maze spatial memory (Hou et al. European J Neuroscience, 20: 1593-1603, 2004). SNAP-25 is expressed not only in the CA1 region, but also in the CA3 region, and the SNAP-25 mRNA level in the CA3 region is higher than in the CA1 region. Here, we provide evidence that SNAP-25 in the CA3 region is also involved in learning/memory. Intra-CA3 infusion of SNAP-25 antisense oligonucleotide impaired both long-term contextual fear memory and water-maze spatial memory, with short-term memory intact. Furthermore, the SNAP-25 antisense oligonucleotide suppressed the long-term potentiation (LTP) of field excitatory post-synaptic potential (fEPSP) in the mossy-fiber pathway (DG-CA3 pathway), with no effect on paired-pulse facilitation of the fEPSP. These results are consistent with the notion that SNAP-25 in the hippocampal CA3 region is required for long-term memory formation

72

Hippocampus-dependent learning influences hippocampal neurogenesis.  

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Full Text Available The structure of the mammalian hippocampus continues to be modified throughout life by continuous addition of neurons in the dentate gyrus. Although the existence of adult neurogenesis is now widely accepted, the function that adult generated granule cells play is a topic of intense debate. Many studies have argued that adult generated neurons, due to unique physiological characteristics, play a unique role in hippocampus-dependent learning and memory. However, it is not currently clear whether this is the case or what specific capability adult generated neurons may confer that developmentally generated neurons do not. These questions have been addressed in numerous ways, from increasing and decreasing neurogenesis to computational modeling. One particular area of research has examined the effects of hippocampus dependent learning on proliferation, survival, integration and activation of immature neurons in response to memory retrieval. Within this subfield there remains a range of data showing that hippocampus dependent learning may increase, decrease or alternatively may not alter these factors. Determining how and when hippocampus-dependent learning alters adult neurogenesis will help to further clarify the role of adult generated neurons. There are many variables (such as age of immature neurons, species, strain, sex, stress, task difficulty and type of learning as well as numerous methodological differences (such as marker type, quantification techniques, apparatus size etc. that could all be crucial for a clear understanding of the interaction between learning and neurogenesis. Here, we review these findings and discuss the different conditions under which hippocampus-dependent learning impacts adult neurogenesis in the dentate gyrus.

JonathanRichardEpp

2013-04-01

73

Making long-term memories in minutes: a time pattern from memory research in education  

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Full Text Available Memory systems select from environmental stimuli those to encode permanently. Repeated stimuli separated by timed spaces without stimuli can initiate Long-Term Potentiation (LTP and long-term memory (LTM encoding. These processes occur in time scales of minutes, and has been demonstrated in many species. This study reports on using a specific timed pattern of three repeated stimuli separated by ten-minute spaces drawn from both behavioural and laboratory studies of LTP and LTM encoding. A technique was developed based on this pattern to test whether encoding complex information into LTM in students was possible using the pattern within a very short time scale. In an educational context, stimuli were periods of highly compressed instruction, and spaces were created through 10 minute distractor activities. Spaced learning in this form was used as the only means of instruction for a national curriculum Biology course, and led to very rapid LTM encoding as measured by the high-stakes test for the course. Remarkably, learning at a greatly increased speed and in a pattern that included deliberate distraction produced significantly higher scores than random answers (p < 0.00001 and scores were not significantly different for experimental groups (one hour spaced learning and control groups (four months teaching. Thus learning per hour of instruction, as measured by the test, was significantly higher for the spaced learning groups (p < 0.00001. In a third condition, spaced learning was used to replace the end of course review for one of two examinations. Results showed significantly higher outcomes for the course using spaced learning (p < 0.0005. The implications of these findings and further areas for research are briefly considered.

PaulKelley

2013-09-01

74

Transcriptional regulation of long-term memory in the marine snail Aplysia  

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Full Text Available Abstract Whereas the induction of short-term memory involves only covalent modifications of constitutively expressed preexisting proteins, the formation of long-term memory requires gene expression, new RNA, and new protein synthesis. On the cellular level, transcriptional regulation is thought to be the starting point for a series of molecular steps necessary for both the initiation and maintenance of long-term synaptic facilitation (LTF. The core molecular features of transcriptional regulation involved in the long-term process are evolutionally conserved in Aplysia, Drosophila, and mouse, and indicate that gene regulation by the cyclic AMP response element binding protein (CREB acting in conjunction with different combinations of transcriptional factors is critical for the expression of many forms of long-term memory. In the marine snail Aplysia, the molecular mechanisms that underlie the storage of long-term memory have been extensively studied in the monosynaptic connections between identified sensory neuron and motor neurons of the gill-withdrawal reflex. One tail shock or one pulse of serotonin (5-HT, a modulatory transmitter released by tail shocks, produces a transient facilitation mediated by the cAMP-dependent protein kinase leading to covalent modifications in the sensory neurons that results in an enhancement of transmitter release and a strengthening of synaptic connections lasting minutes. By contrast, repeated pulses of 5-hydroxytryptamine (5-HT induce a transcription- and translation-dependent long-term facilitation (LTF lasting more than 24 h and trigger the activation of a family of transcription factors in the presynaptic sensory neurons including ApCREB1, ApCREB2 and ApC/EBP. In addition, we have recently identified novel transcription factors that modulate the expression of ApC/EBP and also are critically involved in LTF. In this review, we examine the roles of these transcription factors during consolidation of LTF induced by different stimulation paradigms.

Lee Yong-Seok

2008-06-01

75

Interteaching and Lecture: A Comparison of Long-Term Recognition Memory  

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Although a number of studies suggest that interteaching is an effective alternative to traditional teaching methods, no studies have systematically examined whether interteaching improves long-term memory. In this study, we assigned students to different teaching conditions--interteaching, lecture, or control--and then gave them a multiple-choice…

Saville, Bryan K.; Bureau, Alex; Eckenrode, Claire; Fullerton, Alison; Herbert, Reanna; Maley, Michelle; Porter, Allen; Zombakis, Julie

2014-01-01

76

Protein Phosphatase 1-Dependent Transcriptional Programs for Long-Term Memory and Plasticity  

Science.gov (United States)

Gene transcription is essential for the establishment and the maintenance of long-term memory (LTM) and for long-lasting forms of synaptic plasticity. The molecular mechanisms that control gene transcription in neuronal cells are complex and recruit multiple signaling pathways in the cytoplasm and the nucleus. Protein kinases (PKs) and…

Graff, Johannes; Koshibu, Kyoko; Jouvenceau, Anne; Dutar, Patrick; Mansuy, Isabelle M.

2010-01-01

77

The long-term memory analysis of industrial indices of the Chinese stock market  

International Nuclear Information System (INIS)

The main work of this paper is to apply the fractional market theory and time series analysis for analyzing various industrial indices of the Chinese stock market by rescaling range analysis. Hurst index and the long-term memory of price change in Chinese stock market are studied

78

Weighted Traffic Equilibrium Problem in Non Pivot Hilbert Spaces with Long Term Memory  

International Nuclear Information System (INIS)

In the paper we consider a weighted traffic equilibrium problem in a non-pivot Hilbert space and prove the equivalence between a weighted Wardrop condition and a variational inequality with long term memory. As an application we show, using recent results of the Senseable Laboratory at MIT, how wireless devices can be used to optimize the traffic equilibrium problem.

79

Oscillatory power decreases and long-term memory: the information via desynchronization hypothesis  

OpenAIRE

The traditional belief is that brain oscillations are important for human long-term memory, because they induce synchronized firing between cell assemblies which shapes synaptic plasticity. Therefore, most prior studies focused on the role of synchronization for episodic memory, as reflected in theta (~5 Hz) and gamma (>40 Hz) power increases. These studies, however, neglect the role that is played by neural desynchronization, which is usually reflected in power decreases in the alpha and ...

SimonHanslmayr

2012-01-01

80

Dissociation between memory reactivation and its behavioral expression: scopolamine interferes with memory expression without disrupting long-term storage.  

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The reconsolidation hypothesis has challenged the traditional view of fixed memories after consolidation. Reconsolidation studies have disclosed that the mechanisms mediating memory retrieval and the mechanisms that underlie the behavioral expression of memory can be dissociated, offering a new prospect for understanding the nature of experimental amnesia. The muscarinic antagonist scopolamine has been used for decades to induce experimental amnesias The goal of the present study is to determine whether the amnesic effects of scopolamine are due to storage (or retrieval) deficits or, alternatively, to a decrease in the long-term memory expression of a consolidated long-term memory. In the crab Chasmagnathus memory model, we found that scopolamine-induced amnesia can be reverted by facilitation after reminder presentation. This recovery of memory expression was reconsolidation specific since a reminder that does not triggers reconsolidation process did not allow the recovery. A higher dose (5 ?g/g) of scopolamine induced an amnesic effect that could not be reverted through reconsolidation, and thus it can be explained as an interference with memory storage and/or retrieval mechanisms. These results, showing that an effective amnesic dose of scopolamine (100 ng/g) negatively modulates long-term memory expression but not memory storage in the crab Chasmagnathus, are consistent with the concept that dissociable processes underlie the mechanisms mediating memory reactivation and the behavioral expression of memory. PMID:22960272

Caffaro, Pedro Alejandro; Suárez, Luis Daniel; Blake, Mariano Gillermo; Delorenzi, Alejandro

2012-10-01

81

Minimal effects on human memory following long-term living at moderate altitude.  

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A number of studies describe memory deficits at extremely high altitudes. However, little is known about the effect of long-term living at moderate altitude (MA). The subjects for this study were 52 college students originally from sea level (SL), but studying at a MA of 2260?m over a 7-month period, with a return to SL for 30 days in the middle of the period. Fifty-two matched college students who stayed at SL all the time were the control group. The neuropsychological battery of assessments included the Chinese revised version of Wechsler Memory Scale tests (WMS-CR), verbal and spatial two-back working memory tests, long-term explicit memory (word recall and recognition of words, faces, and pictures) tests, Rey Auditory Verbal Learning test, Rey-Osterrieth Complex Figure (ROCF) test, degraded picture naming test, and the Serial Reaction Time Test. We found that the MA subjects showed significantly poorer performances than SL controls only in short-term visual construction assessed in the visual reproduction test from WMS-CR and in the ROCF immediate test. There were no significant differences in all other tasks between the MA group and SL group. These findings suggest that long-term hypoxic exposure at moderate altitude has minimal effects on human memory. PMID:21452964

Zhang, Jiaxing; Liu, Haichen; Yan, Xiaodan; Weng, Xuchu

2011-01-01

82

Deuterium-depleted water has stimulating effects on long-term memory in rats.  

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Deuterium-depleted water (DDW) is a water which has a 6-7-fold less concentration of the naturally occurring deuterium (20-25ppm vs. 150ppm). While administrated for a longer period, it may reduce the concentration of deuterium throughout the body, thus activating cellular mechanisms which are depending on protons (channels, pumps, enzyme proteins). The aim of the present work was to study, for the first time in our knowledge, the possible influence of deuterium-depleted water (DDW) chronic administration in normal Wistar rats, as compared to a control group which received distilled water, on spatial working memory and the locomotor activity (as studied through Y-maze) or both short-term and long-term spatial memory (assed in radial 8 arms-maze task). Our results presented here showed no significant modifications in terms of spatial working memory (assessed through spontaneous alternation percentage) and locomotor activity (expressed through the number of arm entries) in Y-maze, as a result of DDW ingestion. Also, no significant differences between the DDW and control group were found in terms of the number of working memory errors in the eight-arm radial maze, as a parameter of short-term memory. Still, we observed a significant decrease for the number of reference memory errors in the DDW rats. In this way, we could speculate that the administration of DDW may generate an improvement of the reference memory, as an index of long-term memory. Thus, we can reach the conclusion that the change between the deuterium/hydrogen balance may have important consequences for the mechanisms that govern long-term memory, as showed here especially in the behavioral parameters from the eight-arm radial maze task. PMID:25263786

Mladin, Cristian; Ciobica, Alin; Lefter, Radu; Popescu, Alexandru; Bild, Walther

2014-11-01

83

Similarities and Differences Between Working Memory and Long-Term Memory: Evidence From the Levels-of-Processing Span Task  

OpenAIRE

Two experiments compared the effects of depth of processing on working memory (WM) and long-term memory (LTM) using a levels-of-processing (LOP) span task, a newly developed WM span procedure that involves processing to-be-remembered words based on their visual, phonological, or semantic characteristics. Depth of processing had minimal effect on WM tests, yet subsequent memory for the same items on delayed tests showed the typical benefits of semantic processing. Although the difference in LO...

Rose, Nathan S.; Myerson, Joel; Roediger, Henry L.; Hale, Sandra

2010-01-01

84

Verbal Short-Term Memory Reflects the Organization of Long-Term Memory: Further Evidence from Short-Term Memory for Emotional Words  

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Many studies suggest that long-term lexical-semantic knowledge is an important determinant of verbal short-term memory (STM) performance. This study explored the impact of emotional valence on word immediate serial recall as a further lexico-semantic long-term memory (LTM) effect on STM. This effect is particularly interesting for the study of…

Majerus, Steve; D'Argembeau, Arnaud

2011-01-01

85

Cues, context, and long-term memory: the role of the retrosplenial cortex in spatial cognition  

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Full Text Available Spatial navigation requires representations of landmarks and other navigation cues. The retrosplenial cortex (RSC is anatomically positioned between limbic areas important for memory formation, such as the hippocampus and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly to long-term spatial representation, such as the posterior parietal cortex. Damage to the RSC severely impairs allocentric representations of the environment, including the ability to derive navigational information from landmarks. The specific deficits seen in tests of human and rodent navigation suggest that the RSC supports allocentric representation by processing the stable features of the environment and the spatial relationships among them. In addition to spatial cognition, the RSC plays a key role in contextual and episodic memory. The RSC also contributes importantly to the acquisition and consolidation of long-term spatial and contextual memory through its interactions with the hippocampus. Within this framework, the RSC plays a dual role as part of the feedforward network providing sensory and mnemonic input to the hippocampus and as a target of the hippocampal-dependent systems consolidation of long-term memory.

Adam M P Miller

2014-08-01

86

Reward improves long-term retention of a motor memory through induction of offline memory gains.  

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In humans, training in which good performance is rewarded or bad performance punished results in transient behavioral improvements. The relative effects of reward and punishment on consolidation and long-term retention, critical behavioral stages for successful learning, are not known. Here, we investigated the effects of reward and punishment on these different stages of human motor skill learning. We studied healthy subjects who trained on a motor task under rewarded, punished, or neutral control conditions. Performance was tested before and immediately, 6 hr, 24 hr, and 30 days after training in the absence of reward or punishment. Performance improvements immediately after training were comparable in the three groups. At 6 hr, the rewarded group maintained performance gains, whereas the other two groups experienced significant forgetting. At 24 hr, the reward group showed significant offline (posttraining) improvements, whereas the other two groups did not. At 30 days, the rewarded group retained the gains identified at 24 hr, whereas the other two groups experienced significant forgetting. We conclude that training under rewarded conditions is more effective than training under punished or neutral conditions in eliciting lasting motor learning, an advantage driven by offline memory gains that persist over time. PMID:21419628

Abe, Mitsunari; Schambra, Heidi; Wassermann, Eric M; Luckenbaugh, Dave; Schweighofer, Nicolas; Cohen, Leonardo G

2011-04-12

87

Depletion of Serotonin Selectively Impairs Short-Term Memory without Affecting Long-Term Memory in Odor Learning in the Terrestrial Slug "Limax Valentianus"  

Science.gov (United States)

The terrestrial slug "Limax" is able to acquire short-term and long-term memories during aversive odor-taste associative learning. We investigated the effect of the selective serotonergic neurotoxin 5,7-dihydroxytryptamine (5,7-DHT) on memory. Behavioral studies indicated that 5,7-DHT impaired short-term memory but not long-term memory. HPLC…

Santa, Tomofumi; Kirino, Yutaka; Watanabe, Satoshi; Shirahata, Takaaki; Tsunoda, Makoto

2006-01-01

88

Delayed Dopamine Signaling of Energy Level Builds Appetitive Long-Term Memory in Drosophila  

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Full Text Available Sensory cues relevant to a food source, such as odors, can be associated with post-ingestion signals related either to food energetic value or toxicity. Despite numerous behavioral studies, a global understanding of the mechanisms underlying these long delay associations remains out of reach. Here, we demonstrate in Drosophila that the long-term association between an odor and a nutritious sugar depends on delayed post-ingestion signaling of energy level. We show at the neural circuit level that the activity of two pairs of dopaminergic neurons is necessary and sufficient to signal energy level to the olfactory memory center. Accordingly, we have identified in these dopaminergic neurons a delayed calcium trace that correlates with appetitive long-term memory formation. Altogether, these findings demonstrate that the Drosophila brain remembers food quality through a two-step mechanism that consists of the integration of olfactory and gustatory sensory information and then post-ingestion energetic value.

Pierre-Yves Musso

2015-02-01

89

Measuring capital market efficiency: Long-term memory, fractal dimension and approximate entropy  

OpenAIRE

We utilize long-term memory, fractal dimension and approximate entropy as input variables for the Efficiency Index [Kristoufek & Vosvrda (2013), Physica A 392]. This way, we are able to comment on stock market efficiency after controlling for different types of inefficiencies. Applying the methodology on 38 stock market indices across the world, we find that the most efficient markets are situated in the Eurozone (the Netherlands, France and Germany) and the least efficient ...

Kristoufek, Ladislav; Vosvrda, Miloslav

2014-01-01

90

Protein phosphatase 1-dependent transcriptional programs for long-term memory and plasticity  

OpenAIRE

Gene transcription is essential for the establishment and the maintenance of long-term memory (LTM) and for long-lasting forms of synaptic plasticity. The molecular mechanisms that control gene transcription in neuronal cells are complex and recruit multiple signaling pathways in the cytoplasm and the nucleus. Protein kinases (PKs) and phosphatases (PPs) are important players in these mechanisms. Protein serine/threonine phosphatase 1 (PP1), in particular, was recently shown to be important f...

Gra?ff, Johannes; Koshibu, Kyoko; Jouvenceau, Anne; Dutar, Patrick; Mansuy, Isabelle M.

2010-01-01

91

Protein phosphatase 1 regulates the histone code for long-term memory  

OpenAIRE

Chromatin remodeling through histone posttranslational modifications (PTMs) and DNA methylation has recently been implicated in cognitive functions, but the mechanisms involved in such epigenetic regulation remain poorly understood. Here, we show that protein phosphatase 1 (PP1) is a critical regulator of chromatin remodeling in the mammalian brain that controls histone PTMs and gene transcription associated with long-term memory. Our data show that PP1 is present at the chromatin in brain ce...

Koshibu, Kyoko; Gra?ff, Johannes; Beullens, Monique; Heitz, Fabrice D.; Berchtold, Dominik; Russig, Holger; Farinelli, Me?lissa; Bollen, Mathieu; Mansuy, Isabelle M.

2009-01-01

92

Cues, context, and long-term memory: the role of the retrosplenial cortex in spatial cognition  

OpenAIRE

Spatial navigation requires representations of landmarks and other navigation cues. The retrosplenial cortex (RSC) is anatomically positioned between limbic areas important for memory formation, such as the hippocampus and the anterior thalamus, and cortical regions along the dorsal stream known to contribute importantly to long-term spatial representation, such as the posterior parietal cortex. Damage to the RSC severely impairs allocentric representations of the environment, including the a...

Miller, Adam M. P.

2014-01-01

93

What Infant Memory Tells Us about Infantile Amnesia: Long-Term Recall and Deferred Imitation  

OpenAIRE

Long-term recall memory was assessed using a nonverbal method requiring subjects to reenact a past event from memory (deferred imitation). A large sample of infants (N = 192), evenly divided between 14- and 16-months old, was tested across two experiments. A delay of 2 months was used in Experiment 1 and a delay of 4 months in Experiment 2. In both experiments two treatment groups were used, In one treatment group, motor practice (immediate imitation) was allowed before the delay was imposed;...

Meltzoff, Andrew N.

1995-01-01

94

Long-term memory for odors: influences of familiarity and identification across 64 days.  

Science.gov (United States)

Few studies have investigated long-term odor recognition memory, although some early observations suggested that the forgetting rate of olfactory representations is slower than for other sensory modalities. This study investigated recognition memory across 64 days for high and low familiar odors and faces. Memory was assessed in 83 young participants at 4 occasions; immediate, 4, 16, and 64 days after encoding. The results indicated significant forgetting for odors and faces across the 64 days. The forgetting functions for the 2 modalities were not fundamentally different. Moreover, high familiar odors and faces were better remembered than low familiar ones, indicating an important role of semantic knowledge on recognition proficiency for both modalities. Although odor recognition was significantly better than chance at the 64 days testing, memory for the low familiar odors was relatively poor. Also, the results indicated that odor identification consistency across sessions, irrespective of accuracy, was positively related to successful recognition. PMID:25740304

Cornell Kärnekull, Stina; Jönsson, Fredrik U; Willander, Johan; Sikström, Sverker; Larsson, Maria

2015-05-01

95

Long-term Memory for USD/CNY based on GPH  

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Full Text Available This paper chooses closing price return rate series of USD/CNY to study. Sample interval covers from 22th July 2005 to 15th Sep 2008(before the financial crisis and from 16th September 2008 to 19th May 2010(after the financial crisis.The author put forward GPH and Tapered GPH Method, and concluded through comparable analysis that?In the conditions of V using T0.5?T0.525?T0.55?T0.575?T0.6 samples, standard GPH and tapered GPH tests are adopted. The results show that Fractal dimension parameter d is significantly greater than 0 and the statistics are more than critical value of 1% level before financial crisis USD/CNY. After financial crisis, the parameter has become smaller than that before financial crisis, which is near 0 significantly. In the long term, there is no trend or structural breaks in the exchange market. This study's conclusion was that long-term memory exists in daily return time series of USD/CNY become smaller after financial crisis. Key words: USD/CNY; GPH; Long-term Memory

Fei-xue HUANG

2010-12-01

96

Verapamil enhances the impairing effects of stress on retrieval of long-term memory in rats  

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Full Text Available Introduction: This study investigated an interaction between acute restraint stress and verapamil, as a blocker of L-type voltage sensitive channels on retrieval of long-term memory. Materials and Methods: Young adult male rats were trained in one trial inhibitory avoidance task (1mA, 1.5s footshock. On retention test given 48 hr after training, the latency to re-enter dark compartment and time spent in light chamber of the apparatus were recorded. Thirty min before retention test, the rats were exposed to a 10 min of restraint stress in a Plexiglass with or without prior treatment of verapamil (5, 10, 20 mg/kg. Results: The results showed verapamil pretreatment enhanced the impairing effect of stress on memory retrieval. The applied stress increased circulating corticosterone levels as assessed immediately after the retention test, indicating that stress–induced impairment of memory retrieval is mediated, in part, by increased plasma levels of glucocorticoids. Verapamil did not affect on this response. Conclusion: These findings indicate that acute restraint stress impair retrieval of long-term memory, and provide evidence for the existence of an interaction between stress and L-type voltage calcium channels on this process.

A. Rashidy-Pour

2006-11-01

97

Intrahippocampal glutamine administration inhibits mTORC1 signaling and impairs long-term memory.  

Science.gov (United States)

The mechanistic Target of Rapamycin Complex 1 (mTORC1), a key regulator of protein synthesis and cellular growth, is also required for long-term memory formation. Stimulation of mTORC1 signaling is known to be dependent on the availability of energy and growth factors, as well as the presence of amino acids. In vitro studies using serum- and amino acid-starved cells have reported that glutamine addition can either stimulate or repress mTORC1 activity, depending on the particular experimental system that was used. However, these experiments do not directly address the effect of glutamine on mTORC1 activity under physiological conditions in nondeprived cells in vivo. We present experimental results indicating that intrahippocampal administration of glutamine to rats reduces mTORC1 activity. Moreover, post-training administration of glutamine impairs long-term spatial memory formation, while coadministration of glutamine with leucine had no influence on memory. Intracellular recordings in hippocampal slices showed that glutamine did not alter either excitatory or inhibitory synaptic activity, suggesting that the observed memory impairments may not result from conversion of glutamine to either glutamate or GABA. Taken together, these findings indicate that glutamine can decrease mTORC1 activity in the brain and may have implications for treatments of neurological diseases associated with high mTORC1 signaling. PMID:25878136

Rozas, Natalia S; Redell, John B; Pita-Almenar, Juan D; Mckenna, James; Moore, Anthony N; Gambello, Michael J; Dash, Pramod K

2015-05-01

98

Long-term versus short-term memory deficits for faces in temporal lobe and generalized epilepsy patients.  

Science.gov (United States)

It is still an open question whether short-term and long-term memory are two anatomically dissociable memory systems working in parallel or whether they are represented by neural circuits within similar cortical areas. Epilepsy may be used as a model to study these memory processes. We hypothesized that a double dissociation of short-term and long-term memory exists in temporal lobe epilepsy (TLE) and idiopathic generalized epilepsy (IGE). Immediate and 24-hour face recognition was tested in 10 TLE patients, 9 IGE patients, and 10 healthy controls. TLE patients' immediate recognition was unimpaired, but their memory scores were reduced as compared to healthy controls after 24 hours. In IGE patients, memory was already reduced during immediate recognition. These results are in line with the idea that short-term memory is a transient trace that requires consolidation supported by the medial temporal lobe to change into a more stable status of long-term memory. PMID:20331912

Hötting, Kirsten; Katz-Biletzky, Tall; Malina, Thomas; Lindenau, Matthias; Bengner, Thomas

2010-05-01

99

Fragile X mental retardation 1 and Filamin A interact genetically in Drosophila long-term memory  

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Full Text Available The last decade has witnessed the identification of single-gene defects associated with an impressive number of mental retardation syndromes. Fragile X syndrome, the most common cause of mental retardation for instance, results from disruption of the FMR1 gene. Similarly, Periventricular Nodular Heterotopia (PNH, which includes cerebral malformation, epilepsy and cognitive disabilities, derives from disruption of the Filamin A gene. While it remains unclear whether defects in common molecular pathways may underlie the cognitive dysfunction of these various syndromes, defects in cytoskeletal structure nonetheless appear to be common to several mental retardation syndromes. FMR1 is known to interact with Rac, profilin, PAK and Ras, which are associated with dendritic spine defects. In Drosophila, disruptions of the dFmr1 gene impair long-term memory, and the Filamin A homolog (cheerio was identified in a behavioral screen for long-term memory mutants. Thus, we investigated the possible interaction between cheerio and dFmr1 during long-term memory (LTM formation in Drosophila. We show that LTM specifically is defective in dFmr1/cheerio double heterozygotes, while it is normal in single heterozygotes for either dFmr1 or cheerio. In dFmr1 mutants, Filamin (Cheerio levels are lower than normal after spaced training. These observations support the notion that decreased actin cross-linking underlies the persistence of long and thin dendritic spines in Fragile X patients and animal models. More generally, our results represent the first demonstration of a genetic interaction between mental retardation genes in an in vivo model system of memory formation.

FrancoisBolduc

2010-01-01

100

Extreme event return times in long-term memory processes near 1/f  

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Full Text Available The distribution of extreme event return times and their correlations are analyzed in observed and simulated long-term memory (LTM time series with 1/f power spectra. The analysis is based on tropical temperature and mixing ratio (specific humidity time series from TOGA COARE with 1 min resolution and an approximate 1/f power spectrum. Extreme events are determined by Peak-Over-Threshold (POT crossing. The Weibull distribution represents a reasonable fit to the return time distributions while the power-law predicted by the stretched exponential for 1/f deviates considerably. For a comparison and an analysis of the return time predictability, a very long simulated time series with an approximate 1/f spectrum is produced by a fractionally differenced (FD process. This simulated data confirms the Weibull distribution (a power law can be excluded. The return time sequences show distinctly weaker long-term correlations than the original time series (correlation exponent ??0.56.

F. Sienz

2008-07-01

101

Involvement of translation and transcription processes into neurophysiological mechanisms of long-term memory reconsolidation.  

Science.gov (United States)

We studied the involvement of translation and transcription processes into behavioral and neuronal mechanisms of reconsolidation of the long-term memory of the conditioned taste aversion in edible snails. Injection of cycloheximide (an inhibitor of protein synthesis) to the snails in 48 h after training combined with subsequent reminder and presentation of the conditional stimulus resulted in the development of persistent amnesia and depression of the responses of the defensive behavior command neurons LPl1 and RPl1 to the conditional stimulus. Injection of mRNA synthesis inhibitors actinomycin D or DRB (5,6-dichloro-1-?-D-ribofuranosylbenzimidasole) in 48 h after conditioning with subsequent reminding procedure produced no effects on memory retention and on the responses of the command neurons to the conditional stimulus. The study suggests that the proteins translated from previously synthesized and stored mRNA were involved in the mechanisms of reconsolidation of the memory responsible for conditioned taste aversion. PMID:23658873

Kozyrev, S A; Nikitin, V P

2013-03-01

102

A phenomenological memristor model for short-term/long-term memory  

Science.gov (United States)

Memristor is considered to be a natural electrical synapse because of its distinct memory property and nanoscale. In recent years, more and more similar behaviors are observed between memristors and biological synapse, e.g., short-term memory (STM) and long-term memory (LTM). The traditional mathematical models are unable to capture the new emerging behaviors. In this article, an updated phenomenological model based on the model of the Hewlett-Packard (HP) Labs has been proposed to capture such new behaviors. The new dynamical memristor model with an improved ion diffusion term can emulate the synapse behavior with forgetting effect, and exhibit the transformation between the STM and the LTM. Further, this model can be used in building new type of neural networks with forgetting ability like biological systems, and it is verified by our experiment with Hopfield neural network.

Chen, Ling; Li, Chuandong; Huang, Tingwen; Ahmad, Hafiz Gulfam; Chen, Yiran

2014-08-01

103

Narrative organisation at encoding facilitated children's long-term episodic memory.  

Science.gov (United States)

This study examined the effect of narrative organisation at encoding on long-term episodic memory in a sample of five- to seven-year-old children (N = 113). At an initial interview, children were asked to narrate a story from a picture book. Six months later, they were interviewed again and asked to recall the story and answer a series of direct questions about the story. Children who initially encoded more information in narrative and produced more complete, complex, cohesive and coherent narratives remembered the story in greater detail and accuracy following the six-month interval, independent of age and verbal skills. The relation between narrative organisation and memory was consistent across culture and gender. These findings provide new insight into the critical role of narrative in episodic memory. PMID:24786637

Wang, Qi; Bui, Van-Kim; Song, Qingfang

2015-06-01

104

Spatial coding of ordinal information in short- and long-term memory.  

Science.gov (United States)

The processing of numerical information induces a spatial response bias: Faster responses to small numbers with the left hand and faster responses to large numbers with the right hand. Most theories agree that long-term representations underlie this so called SNARC effect (Spatial Numerical Association of Response Codes; Dehaene et al., 1993). However, a spatial response bias was also observed with the activation of temporary position-space associations in working memory (ordinal position effect; van Dijck and Fias, 2011). Items belonging to the beginning of a memorized sequence are responded to faster with the left hand side while items at the end of the sequence are responded to faster with the right hand side. The theoretical possibility was put forward that the SNARC effect is an instance of the ordinal position effect, with the empirical consequence that the SNARC effect and the ordinal position effect cannot be observed simultaneously. In two experiments we falsify this claim by demonstrating that the SNARC effect and the ordinal position effect are not mutually exclusive. Consequently, this suggests that the SNARC effect and the ordinal position effect result from the activation of different representations. We conclude that spatial response biases can result from the activation of both pre-existing positions in long-term memory and from temporary space associations in working memory at the same time. PMID:25688199

Ginsburg, Véronique; Gevers, Wim

2015-01-01

105

Evidence for two distinct sleep-related long-term memory consolidation processes.  

Science.gov (United States)

Numerous studies examine the effect of a night's sleep on memory consolidation, but few go beyond this short time-scale to test long-lasting effects of sleep on memory. We investigated long-term effects of sleep on typical memory tasks. During the hours following learning, participants slept or stayed awake. We compared recall performance between wake and sleep conditions after delays of up to 6 days. Performance develops in two distinct ways. Word pair, syllable, and motor sequence learning tasks benefit from sleep during the first day after encoding, when compared with daytime or nighttime wakefulness. However, performance in the wake conditions recovers after another night of sleep, so that we observe no lasting effect of sleep. Sleep deprivation before recall does not impair performance. Thus, fatigue cannot adequately explain the lack of long-term effects. We suggest that the hippocampus might serve as a buffer during the retention interval, and consolidation occurs during delayed sleep. In contrast, a non-hippocampal mirror-tracing task benefits significantly from sleep, even when tested after a 4-day delay including recovery sleep. This indicates a dissociation between two sleep-related consolidation mechanisms, which could rely on distinct neuronal processes. PMID:25243990

Schönauer, Monika; Grätsch, Melanie; Gais, Steffen

2015-02-01

106

Sleep Improves Memory: The Effect of Sleep on Long Term Memory in Early Adolescence  

OpenAIRE

Sleep plays an important role in the consolidation of memory. This has been most clearly shown in adults for procedural memory (i.e. skills and procedures) and declarative memory (e.g. recall of facts). The effects of sleep and memory are relatively unstudied in adolescents. Declarative memory is important in school performance and consequent social functioning in adolescents. This is the first study to specifically examine the effects of normal sleep on auditory declarative memory in an earl...

Potkin, Katya Trudeau; Bunney, William E.

2012-01-01

107

Measuring capital market efficiency: Long-term memory, fractal dimension and approximate entropy.  

Czech Academy of Sciences Publication Activity Database

Jihlava : College of Polytechnics Jihlava, 2013 - (Vojackova, H.), s. 470-475 ISBN 978-80-87035-76-4. [International Conference on Mathematical Methods in Economics 2013 /31./. Jihlava (CZ), 11.09.2013-13.09.2013] R&D Projects: GA ?R GA402/09/0965 Grant ostatní: MŠk(CZ) SVV265504 Institutional support: RVO:67985556 Keywords : capital market efficiency * long-range dependence * fractal dimension * approximate entropy Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2013/E/kristoufek-measuring capital market efficienci long-term memory fractal dimension and approximate entropy.pdf

Krištoufek, Ladislav; Vošvrda, Miloslav

108

Measuring capital market efficiency: long-term memory, fractal dimension and approximate entropy  

Science.gov (United States)

We utilize long-term memory, fractal dimension and approximate entropy as input variables for the Efficiency Index [L. Kristoufek, M. Vosvrda, Physica A 392, 184 (2013)]. This way, we are able to comment on stock market efficiency after controlling for different types of inefficiencies. Applying the methodology on 38 stock market indices across the world, we find that the most efficient markets are situated in the Eurozone (the Netherlands, France and Germany) and the least efficient ones in the Latin America (Venezuela and Chile).

Kristoufek, Ladislav; Vosvrda, Miloslav

2014-07-01

109

On the Detection of Long-Term Memory in Short Records  

Science.gov (United States)

Long-term memory is ubiquitous in nature and has important consequences for the occurrence of natural hazards, but its detection often is complicated by the short length of the considered records. Here we study synthetic long-term correlated records of length N that are characterized by a correlation exponent ?, 00)=B· s-? and E=E(B,?,N)= 2B/((2-?)(1-?))· N-?+O(N-1). Due to the finite-size correction E, a direct determination of ? is difficult to achieve and generally leads to an enhanced value of ?. The parameter E also occurs in related quantities, that are characterized by the Hurst-exponent, which describe how the fluctuations of the records in time windows of length s decay with s, for example the variance of the local mean in time windows of length s. We show how to estimate E from a given data set which then allows a more accurate determination of ?. This approach can be applied also to long-term correlated records in the presence of additional white noise, where the determination of ? is particularly difficult (which is the case, e.g. in the records of return intervals between consecutive events above a certain threshold).

Lennartz, S.; Bunde, A.

2008-12-01

110

The evidence for hippocampal long-term potentiation as a basis of memory for simple tasks  

Scientific Electronic Library Online (English)

Full Text Available A potenciação de longa duração (LTP) é o aumento de respostas pós-sinápticas durante horas, dias ou semanas após a breve estimulação repetitiva de aferentes pre-sinápticos. Foi proposto durante 30 anos ser a base da memória de longa duração. Vários achados recentes finalmente apoiaram esta hipótese: [...] a) a formação da memória de esquiva inibitória adquirida numa sessão depende de uma cadeia de processos moleculares na região CA1 do hipocampo quase idêntica à da LTP nessa mesma região; b) LTP hipocampal nessa região acompanha a formação da memóría dessa tarefa e de outra semelhante. No entanto, a LTP de CA1 e os processos de memória podem ser dissociados e, fora disso, processos plásticos em outras regiões cerebrais (amígdala, córtex entorrinal, córtex parietal) também são necessários para a formação da memória da tarefa de uma sessão e talvez de muitas outras. Abstract in english Long-term potentiation (LTP) is the enhancement of postsynaptic responses for hours, days or weeks following the brief repetitive afferent stimulation of presynaptic afferents. It has been proposed many times over the last 30 years to be the basis of long-term memory. Several recent findings finally [...] supported this hypothesis: a) memory formation of one-trial avoidance learning depends on a series of molecular steps in the CA1 region of the hippocampus almost identical to those of LTP in the same region; b)hippocampal LTP in this region accompanies memory formation of that task and of another similar task. However, CA1 LTP and the accompanying memory processes can be dissociated, and in addition plastic events in several other brain regions(amygdala, entorhinal cortex, parietal cortex) are also necessary for memory formation of the one-trial task, and perhaps of many others.

Iván, Izquierdo; Martín, Cammarota; Weber C. Da, Silva; Lia R.M., Bevilaqua; Janine I., Rossato; Juliana S., Bonini; Pamela, Mello; Fernando, Benetti; Jaderson C., Costa; Jorge H., Medina.

2008-03-01

111

The Drosophila cell adhesion molecule Klingon is required for long-term memory formation and is regulated by Notch  

OpenAIRE

The ruslan (rus) mutant was previously identified in a behavioral screen for mutants defective in long-lasting memory, which consists of two consolidated memory types, anesthesia-resistant memory, and protein synthesis-dependent long-term memory (LTM). We demonstrate here that rus is a new allele of klingon (klg), which encodes a homophilic cell adhesion molecule. Klg is acutely required for LTM but not anesthesia-resistant memory formation, and Klg expression increases upon LTM induction. LT...

Matsuno, Motomi; Horiuchi, Junjiro; Tully, Tim; Saitoe, Minoru

2008-01-01

112

Exchange Protein Activated by cAMP Enhances Long-Term Memory Formation Independent of Protein Kinase A  

Science.gov (United States)

It is well established that cAMP signaling within neurons plays a major role in the formation of long-term memories--signaling thought to proceed through protein kinase A (PKA). However, here we show that exchange protein activated by cAMP (Epac) is able to enhance the formation of long-term memory in the hippocampus and appears to do so…

Ma, Nan; Abel, Ted; Hernandez, Pepe J.

2009-01-01

113

The coding theorem for a class of quantum channels with long-term memory  

International Nuclear Information System (INIS)

In this paper, we consider the transmission of classical information through a class of quantum channels with long-term memory, which are convex combinations of memoryless channels. Hence, the memory of such channels can be considered to be given by a Markov chain which is aperiodic but not irreducible. We prove the coding theorem and weak converse for this class of channels. The main techniques that we employ are a quantum version of Feinstein's fundamental lemma (Feinstein A 1954 IRE Trans. PGIT 4 2-22, Khinchin A I 1957 Mathematical Foundations of Information Theory: II. On the Fundamental Theorems of Information Theory (New York: Dover) chapter IV) and a generalization of Helstrom's theorem (Helstrom C W 1976 Quantum detection and estimation theory Mathematics in Science and Engineering vol 123 (London: Academic))

114

Long-term memory in the Irish market (ISEQ): evidence from wavelet analysis  

CERN Document Server

Researchers have used many different methods to detect the possibility of long-term dependence (long memory) in stock market returns, but evidence is in general mixed. In this paper, three different tests, (namely Rescaled Range (R/S), its modified form, and the semi-parametric method (GPH)), in addition to a new approach using the discrete wavelet transform, (DWT), have been applied to the daily returns of five Irish Stock Exchange (ISEQ) indices. These methods have also been applied to the volatility measures (namely absolute and squared returns). The aim is to investigate the existence of long-term memory properties. The indices are Overall, Financial, General, Small Cap and ITEQ and the results of these approaches show that there is no evidence of long-range dependence in the returns themselves, while there is strong evidence for such dependence in the squared and absolute returns. Moreover, the discrete wavelet transform (DWT) provides additional insight on the series breakdown. In particular, in compari...

Sharkasi, A; Crane, M; Sharkasi, Adel; Ruskin, Heather J.; Crane, Martin

2006-01-01

115

Reward improves long-term retention of a motor memory through induction of offline memory gains  

OpenAIRE

In humans, training in which good performance is rewarded or bad performance punished results in transient behavioral improvements [1–3]. Their relative effects on consolidation and long-term retention, critical behavioral stages for successful learning [4, 5], are not known. Here, we investigated the effects of reward and punishment on these different stages of human motor skill learning. We studied healthy subjects who trained on a motor task under rewarded, punished, or neutral control c...

Abe, Mitsunari; Schambra, Heidi; Wassermann, Eric M.; Luckenbaugh, Dave; Schweighofer, Nicolas; Cohen, Leonardo G.

2011-01-01

116

Requirement for Autophagy in the Long-Term Persistence but not Initial Formation of Memory B cells.  

Science.gov (United States)

Autophagy is required for the long-term maintenance of Ag-specific memory B cells. However, whether autophagy is also important for the initial formation of memory B cells remains unclear. In this study, we show that newly generated memory B cells do not display active autophagy but are capable of forming Ab-secreting cells after rechallenge with Ags. Increases in autophagy took place over time after the initial formation of memory B cells. The expression of transcription factors involved in autophagy, but not changes in epigenetic regulation by DNA methylation, was required for autophagy gene expression and the development of active autophagy in memory B cells. This indicates that autophagy is not critical for the initial generation of memory B cells but is required for their long-term persistence. Our results suggest that promoting autophagy to improve Ab-dependent immunological memory is more effective during memory B cell maintenance stage. PMID:25672753

Chen, Min; Kodali, Srikanth; Jang, Albert; Kuai, Le; Wang, Jin

2015-03-15

117

Unforgettable film music: The role of emotion in episodic long-term memory for music  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Specific pieces of music can elicit strong emotions in listeners and, possibly in connection with these emotions, can be remembered even years later. However, episodic memory for emotional music compared with less emotional music has not yet been examined. We investigated whether emotional music is remembered better than less emotional music. Also, we examined the influence of musical structure on memory performance. Results Recognition of 40 musical excerpts was investigated as a function of arousal, valence, and emotional intensity ratings of the music. In the first session the participants judged valence and arousal of the musical pieces. One week later, participants listened to the 40 old and 40 new musical excerpts randomly interspersed and were asked to make an old/new decision as well as to indicate arousal and valence of the pieces. Musical pieces that were rated as very positive were recognized significantly better. Conclusion Musical excerpts rated as very positive are remembered better. Valence seems to be an important modulator of episodic long-term memory for music. Evidently, strong emotions related to the musical experience facilitate memory formation and retrieval.

Altenmüller Eckart O

2008-05-01

118

Errors in nonword repetition: bridging short- and long-term memory  

Directory of Open Access Journals (Sweden)

Full Text Available According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep is a suitable measure of phonological short-term memory for English-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR as a Portuguese-language version. The objectives of the present study were: i to investigate developmental aspects of the phonological memory processing by error analysis in the nonword repetition task, and ii to examine phoneme (substitution, omission and addition and order (migration errors made in the BCPR by 180 normal Brazilian children of both sexes aged 4-10, from preschool to 4th grade. The dominant error was substitution [F(3,525 = 180.47; P < 0.0001]. The performance was age-related [F(4,175 = 14.53; P < 0.0001]. The length effect, i.e., more errors in long than in short items, was observed [F(3,519 = 108.36; P < 0.0001]. In 5-syllable pseudowords, errors occurred mainly in the middle of the stimuli, before the syllabic stress [F(4,16 = 6.03; P = 0.003]; substitutions appeared more at the end of the stimuli, after the stress [F(12,48 = 2.27; P = 0.02]. In conclusion, the BCPR error analysis supports the idea that phonological loop capacity is relatively constant during development, although school learning increases the efficiency of this system. Moreover, there are indications that long-term memory contributes to holding memory trace. The findings were discussed in terms of distinctiveness, clustering and redintegration hypotheses.

F.H. Santos

2006-03-01

119

Protein degradation and protein synthesis in long-term memory formation  

Directory of Open Access Journals (Sweden)

Full Text Available Long-term memory (LTM formation requires transient changes in the activity of intracellular signaling cascades that are thought to regulate new gene transcription and de novo protein synthesis in the brain. Consistent with this, protein synthesis inhibitors impair LTM for a variety of behavioral tasks when infused into the brain around the time of training or following memory retrieval, suggesting that protein synthesis is a critical step in LTM storage in the brain. However, evidence suggests that protein degradation mediated by the ubiquitin-proteasome system may also be a critical regulator of LTM formation and stability following retrieval. This requirement for increased protein degradation has been shown in the same brain regions in which protein synthesis is required for LTM storage. Additionally, increases in the phosphorylation of proteins involved in translational control parallel increases in protein polyubiquitination and the increased demand for protein degradation is regulated by intracellular signaling molecules thought to regulate protein synthesis during LTM formation. In some cases inhibiting proteasome activity can rescue memory impairments that result from pharmacological blockade of protein synthesis, suggesting that protein degradation may control the requirement for protein synthesis during the memory storage process. Results such as these suggest that protein degradation and synthesis are both critical for LTM formation and may interact to properly “consolidate” and store memories in the brain. Here, we review the evidence implicating protein synthesis and degradation in LTM storage and highlight the areas of overlap between these two opposing processes. We also discuss evidence suggesting these two processes may interact to properly form and store memories. LTM storage likely requires a coordinated regulation between protein degradation and synthesis at multiple sites in the mammalian brain.

Fred J Helmstetter

2014-06-01

120

Involvement of protein kinase m? in the maintenance of long-term memory for taste aversion learning in young chicks.  

Science.gov (United States)

The effects of an inhibitor of protein kinase M? on long-term memory were studied using the model of taste aversion in newborn chicks. Memory was impaired by intracerebral injection of 10 or 20 nmol of ?-inhibiting peptide 24 h after training. Memory impairment was found 2 h after peptide administration, and repeated examination 24 h after treatment showed no recovery. Memory impairment was not observed 24 h after inhibitor administration if the testing 2 h after treatment was not performed. The results indicate the contribution of protein kinase M? in the maintenance of long-term memory in the avian brain. These data confirm the hypothesis of several authors that inhibition of protein kinase M? does not abolish memory, but rather interacts with processes of memory retrieval and/or reconsolidation. PMID:25778639

Tiunova, A A; Bezryadnov, D V; Anokhin, K V

2015-03-01

121

Long-Term Memory Deficits in Pavlovian Fear Conditioning in Ca2+/Calmodulin Kinase Kinase ?-Deficient Mice?  

OpenAIRE

Signaling by the Ca2+/calmodulin kinase (CaMK) cascade has been implicated in neuronal gene transcription, synaptic plasticity, and long-term memory consolidation. The CaM kinase kinase ? (CaMKK?) isoform is an upstream component of the CaMK cascade whose function in different behavioral and learning and memory paradigms was analyzed by targeted gene disruption in mice. CaMKK? mutants exhibited normal long-term spatial memory formation and cued fear conditioning but showed deficits in cont...

Blaeser, Frank; Sanders, Matthew J.; Truong, Nga; Ko, Shanelle; Wu, Long Jun; Wozniak, David F.; Fanselow, Michael S.; Zhuo, Min; Chatila, Talal A.

2006-01-01

122

Different Phases of Long-Term Memory Require Distinct Temporal Patterns of PKA Activity after Single-Trial Classical Conditioning  

Science.gov (United States)

The cAMP-dependent protein kinase (PKA) is known to play a critical role in both transcription-independent short-term or intermediate-term memory and transcription-dependent long-term memory (LTM). Although distinct phases of LTM already have been demonstrated in some systems, it is not known whether these phases require distinct temporal patterns…

Michel, Maximilian; Kemenes, Ildiko; Muller, Uli; Kemenes, Gyorgy

2008-01-01

123

Interdisciplinary Approach to the Mental Lexicon: Neural Network and Text Extraction From Long-term Memory  

Directory of Open Access Journals (Sweden)

Full Text Available The paper touches upon the principles of mental lexicon organization in the light of recent research in psycho- and neurolinguistics. As a focal point of discussion two main approaches to mental lexicon functioning are considered: modular or dual-system approach, developed within generativism and opposite single-system approach, representatives of which are the connectionists and supporters of network models. The paper is an endeavor towards advocating the viewpoint that mental lexicon is complex psychological organization based upon specific composition of neural network. In this regard, the paper further elaborates on the matter of storing text in human mental space and introduces a model of text extraction from long-term memory. Based upon data available, the author develops a methodology of modeling structures of knowledge representation in the systems of artificial intelligence.

Vardan G. Arutyunyan

2013-01-01

124

Long-term memory in experiments and numerical simulations of hydrodynamic and magnetohydrodynamic turbulence  

CERN Document Server

We analyze time series stemming from experiments and direct numerical simulations of hydrodynamic and magnetohydrodynamic turbulence. Simulations are done in periodic boxes, but with a volumetric forcing chosen to mimic the geometry of the flow in the experiments, the von K\\'arm\\'an swirling flow between two counter-rotating impellers. Parameters in the simulations are chosen to (within computational limitations) allow comparisons between the experiments and the numerical results. Conducting fluids are considered in all cases. Two different configurations are considered: a case with a weak externally imposed magnetic field, and a case with self-sustained magnetic fields. Evidence of long-term memory and $1/f$ noise is observed in experiments and simulations, in the case with weak magnetic field associated with the hydrodynamic behavior of the shear layer in the von K\\'arm\\'an flow, and in the dynamo case associated with slow magnetohydrodynamic behavior of the large scale magnetic field.

Mininni, Pablo; Odier, Philippe; Pinton, Jean-François; Plihon, Nicolas; Verhille, Gautier; Volk, Romain; Bourgoin, Mickael

2014-01-01

125

Consolidation of visual associative long-term memory in the temporal cortex of primates.  

Science.gov (United States)

Neuropsychological theories have proposed a critical role for the interaction between the medial temporal lobe and the neocortex in the formation of long-term memory for facts and events, which has often been tested by learning of a series of paired words or figures in humans. We have examined neural mechanisms underlying the memory "consolidation" process by single-unit recording and molecular biological methods in an animal model of a visual pair-association task in monkeys. In our previous studies, we found that long-term associative representations of visual objects are acquired through learning in the neural network of the anterior inferior temporal (IT) cortex. In this article, we propose the hypothesis that limbic neurons undergo rapid modification of synaptic connectivity and provide backward signals that guide the reorganization of neocortical neural circuits. Two experiments tested this hypothesis: (1) we examined the role of the backward connections from the medial temporal lobe to the IT cortex by injecting ibotenic acid into the entorhinal and perirhinal cortices, which provided massive backward projections ipsilaterally to the IT cortex. We found that the limbic lesion disrupted the associative code of the IT neurons between the paired associates, without impairing the visual response to each stimulus. (2) We then tested the first half of this hypothesis by detecting the expression of immediate-early genes in the monkey temporal cortex. We found specific expression of zif268 during the learning of a new set of paired associates in the pair-association task, most intensively in area 36 of the perirhinal cortex. All these results with the visual pair-association task support our hypothesis and demonstrate that the consolidation process, which was first proposed on the basis of clinico-psychological evidence, can now be examined in primates using neurophysiolocical and molecular biological approaches. PMID:9753597

Miyashita, Y; Kameyama, M; Hasegawa, I; Fukushima, T

1998-01-01

126

Identification of Gene Expression Changes Associated With Long-Term Memory of Courtship Rejection in Drosophila Males  

OpenAIRE

Long-term memory formation in Drosophila melanogaster is an important neuronal function shaping the insect’s behavioral repertoire by allowing an individual to modify behaviors on the basis of previous experiences. In conditioned courtship or courtship suppression, male flies that have been repeatedly rejected by mated females during courtship advances are less likely than naïve males to subsequently court another mated female. This long-term courtship suppression can last for several days...

Winbush, Ari; Reed, Danielle; Chang, Peter L.; Nuzhdin, Sergey V.; Lyons, Lisa C.; Arbeitman, Michelle N.

2012-01-01

127

The effect of long-term working memory through personalization applied to free recall: uncurbing the primacy-effect enthusiasm.  

Science.gov (United States)

In this study, a personalization method (Guida, Tardieu, & Nicolas, European Journal of Cognitive Psychology, 21: 862-896 2009) was applied to a free-recall task. Fifteen pairs of words, composed of an object and a location, were presented to 93 participants, who had to mentally associate each pair and subsequently recall the objects. A 30-s delay was introduced on half of the trials, the presentation rate was manipulated (5 or 10 s per item), and verbal and visuospatial working memory tests were administered to test for their effects on the serial curve. Two groups were constituted: a personalized group, for whom the locations were well-known places on their university campus, and a nonpersonalized group, for whom the locations did not refer to known places. Since personalization putatively operationalizes long-term working memory (Ericsson & Kintsch, Psychological Review, 102: 211-245 1995)-namely, the capacity to store information reliably and rapidly in long-term memory-and if we take a dual-store approach to memory, the personalization advantage would be expected to be greater for pre-recency than for recency items. Overall, the results were compatible with long-term working memory theory. They contribute to validating the personalization method as a methodology to characterize the contribution of long-term memory storage to performance in working memory tasks. PMID:23297048

Guida, Alessandro; Gras, Doriane; Noel, Yvonnick; Le Bohec, Olivier; Quaireau, Christophe; Nicolas, Serge

2013-05-01

128

Samuel Butler and human long term memory: is the cupboard bare?  

Science.gov (United States)

Memory studies in biological systems distinguish three informational processes that are generally sequential--production/acquisition, storage, and retrieval/use. Identification of DNA as a storage form for hereditary information accelerated progress in that field. Assuming the path of successful elucidation in one memory field (heredity) to be heuristic for elucidation in another (brain), then progress in neuroscience should accelerate when a storage form is identified. In the 19th century Ewald Hering and Samuel Butler held that heredity and brain memory both involved the storage of information and that the two forms of storage were the same. Hering specified storage as 'molecular vibrations' but, while making a fuller case, Butler was less committal. In the 20th century, the ablation studies of Karl Lashley failed to identify unique sites for storage of brain information, and Donald Hebb's 'synaptic plasticity' hypothesis of distributed storage over a neuronal network won favor. In the 21st century this has come under attack, and the idea that brain and hereditary information are stored as DNA is advocated. Thus, albeit without attribution, Butler's idea is reinstated. Yet, while the case is still open, the synaptic plasticity and DNA hypotheses have problems. Two broad alternatives remain on the table. Long term memory is located: (1) in the brain, either in some other macromolecular form (e.g. protein, lipid) or in some sub-molecular form (e.g. quantum computing and 'brain as holograph' hypotheses) or (2) outside the brain. The suggestion of the medieval physician Avicenna that the brain 'cupboard' is bare--i.e. the brain is a perceptual, not storage, organ--is consistent with a mysterious 'universe as holograph' model. Understanding how Butler came to contribute could be heuristic for future progress in a field fraught with 'fractionation and disunity'. PMID:19490862

Forsdyke, Donald R

2009-05-01

129

DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment?  

OpenAIRE

Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. ...

Wittmann, Bianca C.; Tan, Geoffrey C.; Lisman, John E.; Dolan, Raymond J.; Du?zel, Emrah

2013-01-01

130

Inert gas narcosis disrupts encoding but not retrieval of long term memory.  

Science.gov (United States)

Exposure to increased ambient pressure causes inert gas narcosis of which one symptom is long-term memory (LTM) impairment. Narcosis is posited to impair LTM by disrupting information encoding, retrieval (self-guided search), or both. The effect of narcosis on the encoding and retrieval of LTM was investigated by testing the effect of learning-recall pressure and levels of processing (LoP) on the free-recall of word lists in divers underwater. All participants (n=60) took part in four conditions in which words were learnt and then recalled at either low pressure (1.4-1.9atm/4-9msw) or high pressure (4.4-5.0atm/34-40msw), as manipulated by changes in depth underwater: low-low (LL), low-high(LH), high-high (HH), and high-low (HL). In addition, participants were assigned to either a deep or shallow processing condition, using LoP methodology. Free-recall memory ability was significantly impaired only when words were initially learned at high pressure (HH & HL conditions). When words were learned at low pressure and then recalled at low pressure (LL condition) or high pressure (LH condition) free-recall was not impaired. Although numerically superior in several conditions, deeper processing failed to significantly improve free-recall ability in any of the learning-recall conditions. This pattern of results support the hypothesis that narcosis disrupts encoding of information into LTM, while retrieval appears to be unaffected. These findings are discussed in relation to similar effects reported by some memory impairing drugs and the practical implications for workers in pressurised environments. PMID:25725120

Hobbs, Malcolm; Kneller, Wendy

2015-05-15

131

Working memory capacity links cognitive reserve with long-term memory in moderate to severe TBI: a translational approach.  

Science.gov (United States)

Traumatic brain injury (TBI) can have devastating negative consequences on an individuals' ability to remember information; however, there is variability among memory impairment resulting from TBI. Some individuals exhibit long-term memory (LTM) impairment while others do not. This variability has been explained, at least in part, by the theory of cognitive reserve (CR). The theory suggests that individuals who have spent significant time engaged in intellectually enriching activities (higher CR) are better able to withstand LTM impairment despite neurological injury. The cognitive mechanisms that underlie this relationship are not well-specified. Recent evidence suggests that working memory (WM) capacity may be one mediating variable that can help explain how/why cognitive reserve (CR) protects against LTM impairment. The present research tested this hypothesis in a sample of fifty moderate to severe TBI patients. Specific neuropsychological tests were administered to estimate CR, LTM and WM. The results were congruent with a recent theoretical model that implicates WM capacity as a mediating variable in the relationship between CR and LTM (Sobel's Z = 2.62, p = 0.009). These data corroborate recent findings in an alternate neurological population and suggest that WM is an underlying mechanism of CR. Additional research is necessary to establish whether (1) WM is an important individual difference variable to include in memory rehabilitation trials and (2) to determine whether rehabilitation and treatment strategies that specifically target WM may also lead to complimentary improvements on diagnostic tests of delayed LTM in TBI and other memory impaired populations. PMID:25287019

Sandry, Joshua; DeLuca, John; Chiaravalloti, Nancy

2015-01-01

132

Zif268/Egr1 gain of function facilitates hippocampal synaptic plasticity and long-term spatial recognition memory.  

Science.gov (United States)

It is well established that Zif268/Egr1, a member of the Egr family of transcription factors, is critical for the consolidation of several forms of memory; however, it is as yet uncertain whether increasing expression of Zif268 in neurons can facilitate memory formation. Here, we used an inducible transgenic mouse model to specifically induce Zif268 overexpression in forebrain neurons and examined the effect on recognition memory and hippocampal synaptic transmission and plasticity. We found that Zif268 overexpression during the establishment of memory for objects did not change the ability to form a long-term memory of objects, but enhanced the capacity to form a long-term memory of the spatial location of objects. This enhancement was paralleled by increased long-term potentiation in the dentate gyrus of the hippocampus and by increased activity-dependent expression of Zif268 and selected Zif268 target genes. These results provide novel evidence that transcriptional mechanisms engaging Zif268 contribute to determining the strength of newly encoded memories. PMID:24298160

Penke, Zsuzsa; Morice, Elise; Veyrac, Alexandra; Gros, Alexandra; Chagneau, Carine; LeBlanc, Pascale; Samson, Nathalie; Baumgärtel, Karsten; Mansuy, Isabelle M; Davis, Sabrina; Laroche, Serge

2014-01-01

133

The Drosophila cell adhesion molecule klingon is required for long-term memory formation and is regulated by Notch.  

Science.gov (United States)

The ruslan (rus) mutant was previously identified in a behavioral screen for mutants defective in long-lasting memory, which consists of two consolidated memory types, anesthesia-resistant memory, and protein synthesis-dependent long-term memory (LTM). We demonstrate here that rus is a new allele of klingon (klg), which encodes a homophilic cell adhesion molecule. Klg is acutely required for LTM but not anesthesia-resistant memory formation, and Klg expression increases upon LTM induction. LTM formation also requires activity of the Notch cell-surface receptor. Although defects in Notch have been implicated in memory loss because of Alzheimer's disease, downstream signaling linking Notch to memory have not been determined. Strikingly, we found that Notch activity increases upon LTM induction and regulates Klg expression. Furthermore, Notch-induced enhancement of LTM is disrupted by a klg mutation. We propose that Klg is a downstream effector of Notch signaling that links Notch activity to memory. PMID:19104051

Matsuno, Motomi; Horiuchi, Junjiro; Tully, Tim; Saitoe, Minoru

2009-01-01

134

Molecular mechanisms underlying formation of long-term reward memories and extinction memories in the honeybee (Apis mellifera).  

Science.gov (United States)

The honeybee (Apis mellifera) has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a flower's characteristic features with a reward in a way that resembles olfactory appetitive classical conditioning, a learning paradigm that is used to study mechanisms underlying learning and memory formation in the honeybee. Due to a plethora of studies on appetitive classical conditioning and phenomena related to it, the honeybee is one of the best characterized invertebrate model organisms from a learning psychological point of view. Moreover, classical conditioning and associated behavioral phenomena are surprisingly similar in honeybees and vertebrates, suggesting a convergence of underlying neuronal processes, including the molecular mechanisms that contribute to them. Here I review current thinking on the molecular mechanisms underlying long-term memory (LTM) formation in honeybees following classical conditioning and extinction, demonstrating that an in-depth analysis of the molecular mechanisms of classical conditioning in honeybees might add to our understanding of associative learning in honeybees and vertebrates. PMID:25225299

Eisenhardt, Dorothea

2014-10-01

135

Long-term memory formation in Drosophila requires training-dependent glial transcription.  

Science.gov (United States)

Long-term memory (LTM) formation requires de novo gene expression in neurons, and subsequent structural and functional modification of synapses. However, the importance of gene expression in glia during this process has not been well studied. In this report, we characterize a cell adhesion molecule, Klingon (Klg), which is required for LTM formation in Drosophila. We found that Klg localizes to the juncture between neurons and glia, and expression in both cell types is required for LTM. We further found that expression of a glial gene, repo, is reduced in klg mutants and knockdown lines. repo expression is required for LTM, and expression increases upon LTM induction. In addition, increasing repo expression in glia is sufficient to restore LTM in klg knockdown lines. These data indicate that neuronal activity enhances Klg-mediated neuron-glia interactions, causing an increase in glial expression of repo. Repo is a homeodomain transcription factor, suggesting that further downstream glial gene expression is also required for LTM. PMID:25855172

Matsuno, Motomi; Horiuchi, Junjiro; Yuasa, Yoshihiro; Ofusa, Kyoko; Miyashita, Tomoyuki; Masuda, Tomoko; Saitoe, Minoru

2015-04-01

136

Low environmental calcium blocks long-term memory formation in a freshwater pulmonate snail.  

Science.gov (United States)

The freshwater snail Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg/l environmental calcium. Although it has no apparent effect on survival at 20 mg/l, reducing environmental calcium increases metabolic demand, and as such we consider that this level of calcium acts as a stressor on the snail. We exposed snails to acute periods of low environmental calcium and tested their ability to form intermediate-term memory (ITM) and long-term memory (LTM) following one trial operant conditioning (1TT) to reduce aerial respiratory activity in hypoxic conditions. We also assessed whether there were changes in the electrophysiological properties of a single neuron, right pedal dorsal 1 (RPeD1), which has been demonstrated to be necessary for LTM formation. Following training in high (80 mg/l) environmental calcium, L. stagnalis formed ITM and LTM lasting 24 h and demonstrated a significant reduction in all activity measured from RPeD1; however when snails were exposed to low (20 mg/l) environmental calcium they were able to form ITM but not LTM. Although no behavioral LTM was formed, a partial reduction in RPeD1 activtiy measured 24 h after training was observed, indicating a residual effect of training. The strong effect that environmental calcium concentration had on physiology and behavior in response to training to reduce aerial respiration in L. stagnalis suggests that it is an element of gastropod husbandry that needs to be carefully considered when studying other traits. This study also indicates that L. stagnalis found naturally in low calcium environments may be less able to adapt to novel stressors than populations found in harder waters. PMID:21130174

Dalesman, Sarah; Braun, Marvin H; Lukowiak, Ken

2011-05-01

137

Effects of viewing ordered pictorial reminders on long-term memory in the first year of life.  

Science.gov (United States)

Previous research has shown that reminders can be effective for extending and enhancing a variety of kinds of memory in infants. We investigated the effects of viewing pictorial representations of actions that were included in imitation events used to measure long-term memory in young infants. Infants who saw the pictures of actions displayed in the order in which they comprised events showed evidence of memory for the events. Infants who saw the actions presented randomly did not. These results suggest that pictures presented during the consolidation and storage phase of memory formation can be effective reminders of events for young infants. PMID:21999206

Carver, Leslie J

2011-11-01

138

Fan-Shaped Body Neurons Are Involved in "Period"-Dependent Regulation of Long-Term Courtship Memory in "Drosophila"  

Science.gov (United States)

In addition to its established function in the regulation of circadian rhythms, the "Drosophila" gene "period" ("per") also plays an important role in processing long-term memory (LTM). Here, we used courtship conditioning as a learning paradigm and revealed that (1) overexpression and knocking down of "per" in subsets of brain neurons enhance and…

Sakai, Takaomi; Inami, Show; Sato, Shoma; Kitamoto, Toshihiro

2012-01-01

139

Long-Term Perceptual Memory in Educable and Trainable Retardates and Children with Learning Disabilities. Final Report.  

Science.gov (United States)

Three short studies were conducted on long-term effects of visual perception training on perceptual memory, involving the visual illusion of apparent movement, in educable and trainable mentally retarded children (EMR and TMR) and in learning disabled children (LD). Variables were lengths of training session and retention interval. Tables…

Raskin, Larry M.

140

Effect of zinc supplementation of pregnant rats on short-term and long-term memory of their offspring  

International Nuclear Information System (INIS)

To see the dose dependent effects of zinc chloride on the short-term and long-term memory in a shuttle box (rats). Six pair adult wistar rats were taken for this experiment. One group of pregnant rats received a daily oral dose of 20 mg/kg Zn as zinc chloride and the remaining groups received a daily oral dose of (30, 50, 70,100 mg/kg) zinc chloride for two weeks by gavage. One month after birth, a shuttle box was used to test short-term and long-term memory. Two criteria were considered to behavioral test, including latency in entering dark chamber and time spent in the dark chamber. This experiment showed that oral administration of ZnCl/sub 2/ with (20, 30, 50 mg/kg/day) doses after 2 weeks at the stage of pregnancy, can improve the working memory of their offspring (p<0.05). Where as ZnCl/sub 2/ with 30 mg/kg/day dose has been more effective than other doses (p<0.001). But rat which received ZnCl/sub 2/ with 100 mg/kg/day at the stage of pregnancy, has shown significant impairment in working (short-term) memory of their offspring (p<0.05) and there was no significant difference in reference (long-term) memory 3 for any of groups. This study has demonstrated that zinc chloride consumption with 30 mg/kg/day dose for two weeks at the stage of pregnancy in rats, has positive effect on short-term memory on their offspring. But consumption of enhanced zinc 100 mg/kg/day in pregnant rats can cause short-term memory impairment. On the other hand, zinc supplementation such the other hand, zinc supplementation such as zinc chloride has no effect on long-term memory. (author)

141

Susceptibility to induction of long-term depression is associated with impaired memory in aged Fischer 344 rats  

OpenAIRE

The current study employed aged and young male Fischer 344 rats to examine the relationship between long-term depression (LTD), age, and memory. Memory performance was measured on two tasks that are sensitive to hippocampal function; inhibitory avoidance and spatial discrimination on the Morris water maze. The slope of the extracellular excitatory postsynaptic field potential was recorded from CA3-CA1 synapses in hippocampal slices. Low frequency stimulation (LFS) induced a modest LTD only in...

Foster, Thomas C.; Kumar, Ashok

2007-01-01

142

A Diffusion Model Analysis of Adult Age Differences in Episodic and Semantic Long-Term Memory Retrieval  

OpenAIRE

Two experiments investigated adult age differences in episodic and semantic long-term memory tasks, as a test of the hypothesis of specific age-related decline in context memory. Older adults were slower and exhibited lower episodic accuracy than younger adults. Fits of the diffusion model (R. Ratcliff, 1978) revealed age-related increases in nondecisional reaction time for both episodic and semantic retrieval. In Experiment 2, an age difference in boundary separation also indicated an age-re...

Spaniol, Julia; Madden, David J.; Voss, Andreas

2006-01-01

143

On the interplay between short and long term memory in the power-law cross-correlations setting  

CERN Document Server

We focus on emergence of the power-law cross-correlations from processes with both short and long term memory properties. In the case of correlated error-terms, the power-law decay of the cross-correlation function comes automatically with the characteristics of the separate processes. The bivariate Hurst exponent is then equal to an average of the separate Hurst exponents of the analysed processes. Strength of the short term memory has no effect on these asymptotic properties.

Kristoufek, Ladislav

2014-01-01

144

Long-term olfactory memories are stabilised via protein synthesis in Camponotus fellah ants  

DEFF Research Database (Denmark)

Ants exhibit impressive olfactory learning abilities. Operant protocols in which ants freely choose between rewarded and nonrewarded odours have been used to characterise associative olfactory learning and memory. Yet, this approach precludes the use of invasive methods allowing the dissection of molecular bases of learning and memory. An open question is whether the memories formed upon olfactory learning that are retrievable several days after training are indeed based on de novo protein synthesis. Here, we addressed this question in the ant Camponotus fellah using a conditioning protocol in which individually harnessed ants learn an association between odour and reward. When the antennae of an ant are stimulated with sucrose solution, the insect extends its maxilla–labium to absorb the solution (maxilla–labium extension response). We differentially conditioned ants to discriminate between two long-chain hydrocarbons, one paired with sucrose and the other with quinine solution. Differential conditioning leads to the formation of a long-term memory retrievable at least 72¿h after training. Long-term memory consolidation was impaired by the ingestion of cycloheximide, a protein synthesis blocker, prior to conditioning. Cycloheximide did not impair acquisition of either short-term memory (10¿min) or early and late mid-term memories (1 or 12¿h). These results show that, upon olfactory learning, ants form different memories with variable molecular bases. While short- and mid-term memories do not require protein synthesis, long-term memories are stabilised via protein synthesis. Our behavioural protocol opens interesting research avenues to explore the cellular and molecular bases of olfactory learning and memory in ants.

Guerrieri, Fernando Javier; D'Ettorre, Patrizia

2011-01-01

145

2010 Survey on long-term preservation of information and memory for geological disposal of radioactive waste  

International Nuclear Information System (INIS)

Preservation of information and memory across generations is a cross-cutting theme of increasing importance for radioactive waste management. Because of the experience accumulated by the advanced national programmes that the RWMC represents, and the breadth of its related high-level initiatives, the Committee is uniquely placed internationally to combine resources and help develop state-of-the-art guidance on the long-term preservation of information and memory. In the context of fostering knowledge consolidation and transfer (KCT), the RWMC has already identified - in its reference document on KCT - the area of inter-generational transfer of knowledge as one of two areas needing development. In 2009, the RWMC decided to implement its programme of work in the area of information preservation and long-term memory as a series of projects or lines of actions opened by the RWMC and supervised by its Bureau. In order to better define its first series of projects the RWMC preformed a survey of its organisations needs and available materials and experience. At its meeting in 2010 the RWMC determined that the survey materials provided by organisations from 12 NEA countries constitute a good contribution to the literature in this field, and certainly to the upcoming projects. They provide as well a good baseline of information against which to measure progress a few years hence. This document reports the answers provided by organisations from 12 countries (Belgium, Canada, Finland, France, Hungary, Japan, Korea, Spain, Sweden, Switzerland, United Kingdom, and the USA,) to five questions related to long-term preservation of information and memory in the field of geological disposal. The questions are as follows: o What specific priority areas for long-term memory development have been identified in your agencies/countries? Which are the time scales of largest interest? o Do these priority proceed from good practice or/and from specific laws, regulations, policies exist in your country that set out requirements for long-term memory in long-term waste management? o How far advanced are you regarding establishing an action plan for long-term information and memory preservation in the field of geological disposal? Are you addressing the following RWMC questions: What information should be preserved? Why? Where? How should it be preserved? Which target groups? Which time horizons? What suggestions do you have for possible areas of focus for RWMC? (e.g. an international project that may assist Members?) What are the untapped areas that deserve more attention? Would you have studies, reports, policies that you might share with RWMC members? (author)

146

The role of the BDNF Val66Met polymorphism in individual differences in long-term memory capacity.  

Science.gov (United States)

The protein brain-derived neurotrophic factor (BDNF) plays an important role in diverse memory processes and is strongly expressed in the hippocampus. The hippocampus itself is a key structure involved in the processing of information from short-term to long-term memory. Due to the putative role of BDNF in memory consolidation, a prominent single nucleotide polymorphism (SNP) on the BDNF gene (BDNF Val66Met) was investigated in the context of long-term memory performance. N=138 students were presented with 40 words from 10 categories, each consisting of eight words such as 'fruits' or 'vehicles' in a memory recognition task (specifically the Deese-Roediger-McDermott Paradigm). Recognition performance was analyzed 25 min after the initial presentation of the word list and subsequently 1 week after the initial presentation. Overall, individual long-term memory performance immediately after learning the word list (T1) and performance 1 week later (T2) did not differ on the basis of the BDNF SNP, but an interaction effect of BDNF Val66Met by time-of-recall was found: Carriers of the Met66+ variant showed the strongest decline in hit rate performance over time. PMID:25267504

Montag, Christian; Felten, Andrea; Markett, Sebastian; Fischer, Luise; Winkel, Katja; Cooper, Andrew; Reuter, Martin

2014-12-01

147

Two Pairs of Mushroom Body Efferent Neurons Are Required for Appetitive Long-Term Memory Retrieval in Drosophila  

Directory of Open Access Journals (Sweden)

Full Text Available One of the challenges facing memory research is to combine network- and cellular-level descriptions of memory encoding. In this context, Drosophila offers the opportunity to decipher, down to single-cell resolution, memory-relevant circuits in connection with the mushroom bodies (MBs, prominent structures for olfactory learning and memory. Although the MB-afferent circuits involved in appetitive learning were recently described, the circuits underlying appetitive memory retrieval remain unknown. We identified two pairs of cholinergic neurons efferent from the MB ? vertical lobes, named MB-V3, that are necessary for the retrieval of appetitive long-term memory (LTM. Furthermore, LTM retrieval was correlated to an enhanced response to the rewarded odor in these neurons. Strikingly, though, silencing the MB-V3 neurons did not affect short-term memory (STM retrieval. This finding supports a scheme of parallel appetitive STM and LTM processing.

Pierre-Yves Plaçais

2013-11-01

148

Inhibitors of cAMP-dependent protein kinase impair long-term memory formation in day-old chicks.  

Science.gov (United States)

There is substantial evidence that protein kinases, through the phosphorylation of substrate proteins, play a significant role in information processing in the brain, including processes underlying memory formation. Inhibition of the activity of the cyclic-adenosine monophosphate-dependent protein kinase A by the highly specific inhibitor, halofantrine, resulted in impairment of memory formation in day-old chicks trained on a single-trial passive avoidance task. A dose of 9.6 ng/chick halofantrine induced amnesia at the beginning of a protein synthesis-dependent long-term memory stage, the last of three stages of memory postulated to underly memory formation in the chick following passive avoidance learning. The concentration of halofantrine required for 50% inhibition of chick brain protein kinase A was found to be similar to that observed for bovine heart and rat liver. The amnestic effect of halofantrine is tentatively attributed to interference with de novo protein synthesis necessary for long-term memory consolidation. Neither anthraquinone nor the anthraquinone derivative anthraflavic acid, which have little effect on protein kinase A activity, affected memory retention. On the other hand, two other anthraquinone derivatives, chrysophanic acid and purpurin, which inhibit PKA activity, at doses of 0.25 and 0.5 ng/chick also yielded retention deficits. In these cases, however, retention losses occurred earlier than observed with halofantrine, at about 30 min post-training. The earlier effects of these inhibitors may be due to the additional inhibitory action of these compounds on protein kinase C activity, which has been demonstrated in previous studies to be implicated, possibly through phosphorylation of the GAP43 phosphoprotein, in memory processing in the stage of memory immediately preceding the protein synthesis-dependent long-term stage. PMID:7582818

Zhao, W Q; Polya, G M; Wang, B H; Gibbs, M E; Sedman, G L; Ng, K T

1995-09-01

149

Long-Term Effects of Neonatal Single or Multiple Isoflurane Exposures on Spatial Memory in Rats  

OpenAIRE

General anesthetics are neurotoxic to neonatal rodents and non-human primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated...

Murphy, Kathy L.; Baxter, Mark G.

2013-01-01

150

Long-term effects of neonatal single or multiple isoflurane exposures on spatial memory in rats  

OpenAIRE

General anesthetics are neurotoxic to neonatal rodents and nonhuman primates. Neonatal exposure to general anesthetics has been associated with long-term cognitive deficits in animal models. Some data from humans are consistent with long-term deleterious effects of anesthetic exposure early in life on cognitive development, with multiple exposures to general anesthetics being particularly damaging. We sought to determine whether repeated exposure of neonatal rats to anesthesia was associated...

MarkGBaxter; KathyLMurphy

2013-01-01

151

Pre-learning stress that is temporally removed from acquisition exerts sex-specific effects on long-term memory.  

Science.gov (United States)

We have examined the influence of sex and the perceived emotional nature of learned information on pre-learning stress-induced alterations of long-term memory. Participants submerged their dominant hand in ice cold (stress) or warm (no stress) water for 3 min. Thirty minutes later, they studied 30 words, rated the words for their levels of emotional valence and arousal and were then given an immediate free recall test. Twenty-four hours later, participants' memory for the word list was assessed via delayed free recall and recognition assessments. The resulting memory data were analyzed after categorizing the studied words (i.e., distributing them to "positive-arousing", "positive-non-arousing", "negative-arousing", etc. categories) according to participants' valence and arousal ratings of the words. The results revealed that participants exhibiting a robust cortisol response to stress exhibited significantly impaired recognition memory for neutral words. More interestingly, however, males displaying a robust cortisol response to stress demonstrated significantly impaired recall, overall, and a marginally significant impairment of overall recognition memory, while females exhibiting a blunted cortisol response to stress demonstrated a marginally significant impairment of overall recognition memory. These findings support the notion that a brief stressor that is temporally separated from learning can exert deleterious effects on long-term memory. However, they also suggest that such effects depend on the sex of the organism, the emotional salience of the learned information and the degree to which stress increases corticosteroid levels. PMID:23266791

Zoladz, Phillip R; Warnecke, Ashlee J; Woelke, Sarah A; Burke, Hanna M; Frigo, Rachael M; Pisansky, Julia M; Lyle, Sarah M; Talbot, Jeffery N

2013-02-01

152

Long-term maintenance of smartphone and PDA use in individuals with moderate to severe memory impairment.  

Science.gov (United States)

In an earlier paper we described a structured, theory-driven training programme which was administered to 10 individuals with moderate-to-severe memory impairment. All individuals received an errorless-fading-of-cues protocol in the use of personal digital assistants (PDAs) or smartphones (Svoboda, Richards, Leach, & Mertens, 2012 ) and demonstrated generalisation of acquired skills to day-to-day memory challenges. Maintenance of intervention gains over the long-term is another indicator of successful generalisation. Here we present the maintenance of device use in the same group of individuals 12 to 19?months after programme completion. A within-subject, ABABB multi-case experimental design was used to evaluate the impact of PDA or smartphone use on day-to-day memory functioning at baseline, immediately post-intervention, at return to baseline, and at short-term and long-term follow-up. Results presented here focus predominantly on long-term follow-up. All 10 individuals showed maintenance of gains in day-to-day functioning as quantified across several ecologically valid questionnaire and task-based measures. This was corroborated by family members with whom six of the participants resided. This study further demonstrates the programme's clinical effectiveness in enabling individuals with moderate-to-severe memory impairment to function more independently and with greater confidence up to 19?months following programme completion. PMID:24945553

Svoboda, Eva; Richards, Brian; Yao, Christie; Leach, Larry

2015-06-01

153

Hippocampal dynamics of synaptic NF-kappa B during inhibitory avoidance long-term memory consolidation in mice.  

Science.gov (United States)

Since the discovery that long-term memory is dependent on protein synthesis, several transcription factors have been found to participate in the transcriptional activity needed for its consolidation. Among them, NF-kappa B is a constitutive transcription factor whose nuclear activity has proven to be necessary for the consolidation of inhibitory avoidance in mice. This transcription factor has a wide distribution in the nervous system, with a well-reported presence in dendrites and synaptic terminals. Here we report changes in synaptosomal NF-kappa B localization and activity, during long-term memory consolidation. Activity comparison of synaptosomal and nuclear NF-kappa B, indicates different dynamics for both localizations. In this study we identify two pools of synaptosomal NF-kappa B, one obtained with the synaptoplasm (free fraction) and the second bound to the synaptosomal membranes. During the early steps of consolidation the first pool is activated, as the membrane associated transcription factor fraction increases and concomitantly the free fraction decreases. These results suggest that the activation of synaptic NF-kappa B and its translocation to membranes are part of the consolidation of long-term memory in mice. PMID:25659345

Salles, A; Boccia, M; Blake, M; Corbi, N; Passananti, C; Baratti, C M; Romano, A; Freudenthal, R

2015-04-16

154

Long-term effects of an acute and systemic administration of LPS on adult neurogenesis and spatial memory  

Directory of Open Access Journals (Sweden)

Full Text Available The cognitive reserve is the capacity of the brain to maintain normal performance while exposed to insults or ageing. Increasing evidences point to a role for the interaction between inflammatory conditions and cognitive reserve status during Alzheimer's disease (AD progression. The production of new neurons along adult life can be considered as one of the components of the cognitive reserve. Interestingly, adult neurogenesis is decreased in mouse models of AD and following inflammatory processes. The aim of this work is to reveal the long-term impact of a systemic inflammatory event on memory and adult neurogenesis in wild type (WT and triple transgenic mouse model of AD (3xTg-AD.4 month-old mice were intraperitoneally injected once with saline or lipopolysaccharide (LPS and their performance on spatial memory analyzed with the Morris water maze (MWM test 7 weeks later. Our data showed that a single intraperitoneal injection with LPS has a long-term impact in the production of hippocampal neurons. Consistently, LPS-treated WT mice showed less doublecortin-positive neurons, less synaptic contacts in newborn neurons, and decreased dendritic volume and complexity. These surprising observations were accompanied with memory deficits. 3xTg-AD mice showed a decrease in new neurons in the dentate gyrus compatible with, although exacerbated, the pattern observed in WT LPS-treated mice. In 3xTg-AD mice, LPS injection did not significantly affected the production of new neurons but reduced their number of synaptic puncta and impaired memory performance, when compared to the observations made in saline-treated 3xTg-AD mice. These data indicate that LPS treatment induces a long-term impairment on hippocampal neurogenesis and memory. Our results show that acute neuroinflammatory events influence the production of new hippocampal neurons, affecting the cognitive reserve and leading to the development of memory deficits associated to Alzheimer's disease pathology.

JoãoO.Malva

2014-04-01

155

On the interplay between short and long term memory in the power-law cross-correlations setting  

Science.gov (United States)

We focus on emergence of the power-law cross-correlations from processes with both short and long term memory properties. In the case of correlated error-terms, the power-law decay of the cross-correlation function comes automatically with the characteristics of separate processes. Bivariate Hurst exponent is then equal to an average of separate Hurst exponents of the analyzed processes. Strength of short term memory has no effect on these asymptotic properties. Implications of these findings for the power-law cross-correlations concept are further discussed.

Kristoufek, Ladislav

2015-03-01

156

Improved long-term memory via enhancing cGMP-PKG signaling requires cAMP-PKA signaling.  

Science.gov (United States)

Memory consolidation is defined by the stabilization of a memory trace after acquisition, and consists of numerous molecular cascades that mediate synaptic plasticity. Commonly, a distinction is made between an early and a late consolidation phase, in which early refers to the first hours in which labile synaptic changes occur, whereas late consolidation relates to stable and long-lasting synaptic changes induced by de novo protein synthesis. How these phases are linked at a molecular level is not yet clear. Here we studied the interaction of the cyclic nucleotide-mediated pathways during the different phases of memory consolidation in rodents. In addition, the same pathways were studied in a model of neuronal plasticity, long-term potentiation (LTP). We demonstrated that cGMP/protein kinase G (PKG) signaling mediates early memory consolidation as well as early-phase LTP, whereas cAMP/protein kinase A (PKA) signaling mediates late consolidation and late-phase-like LTP. In addition, we show for the first time that early-phase cGMP/PKG signaling requires late-phase cAMP/PKA-signaling in both LTP and long-term memory formation. PMID:24813825

Bollen, Eva; Puzzo, Daniela; Rutten, Kris; Privitera, Lucia; De Vry, Jochen; Vanmierlo, Tim; Kenis, Gunter; Palmeri, Agostino; D'Hooge, Rudi; Balschun, Detlef; Steinbusch, Harry M W; Blokland, Arjan; Prickaerts, Jos

2014-10-01

157

The role of reconsolidation and the dynamic process of long-term memory formation and storage  

Directory of Open Access Journals (Sweden)

Full Text Available It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the physical changes underlying the encoding and processing of the information (memory trace or engram remain in a fragile state for some time. However, over time, the new memory becomes increasingly resistant to disruption until it is consolidated. Retrieval or reactivation of an apparently consolidated memory can render the memory labile again, and reconsolidation is the process that occurs to mediate its restabilization. Reconsolidation also evolves with the age of the memory: Young memories are sensitive to postreactivation disruption, but older memories are more resistant. Why does a memory become labile again if it is retrieved or reactivated? Here I suggest that the main function of reconsolidation is to contribute to the lingering consolidation process and mediate memory strengthening. I also discuss the literature and results regarding the influence of the passage of time on the reconsolidation of memory. These points have important implications for the use of reconsolidation in therapeutic settings.

CristinaMAlberini

2011-03-01

158

The role of reconsolidation and the dynamic process of long-term memory formation and storage  

OpenAIRE

It is becoming increasingly clear that the processes of memory formation and storage are exquisitely dynamic. Elucidating the nature and temporal evolution of the biological changes that accompany encoding, storage and retrieval is key to understand memory formation. For explicit or medial temporal lobe-dependent memories that form after a discrete event and are stored for a long time, the physical changes underlying the encoding and processing of the information (memory trace or engram) rema...

CristinaMAlberini

2011-01-01

159

Four-Month-Old Infants’ Long-Term Memory for a Stressful Social Event  

OpenAIRE

Infants clearly show an early capacity for memory for inanimate emotionally neutral events. However, their memory for social stress events has received far less attention. The aim of the study was to investigate infants’ memory for a stressful social event (i.e., maternal unresponsiveness during the Still-Face paradigm) after a 15-day recall interval using changes in behavioral responses and salivary post-stress cortisol reactivity as measures of memory. Thirty-seven infants were exposed to...

Montirosso, Rosario; Tronick, Ed; Morandi, Francesco; Ciceri, Francesca; Borgatti, Renato

2013-01-01

160

Evidence for long-term cross-language repetition priming in conceptual implicit memory tasks  

OpenAIRE

Previous studies have failed to find evidence for long-term cross-language repetition priming (e.g., presentation of the English word frog does not facilitate responding to its Dutch translation equivalent kikker on a later presentation). The present study tested the hypothesis that failure to find cross-language repetition priming in previous studies was due to the use of tasks that rely primarily on lexical or orthographic processing of the stimuli instead of conceptual ...

Zeelenberg, R.; Pecher, D.

2003-01-01

161

Olfaction, Emtion & the Amygdala: arousal-dependent modulation of long-term autobiographical memory and its association with olfaction  

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Full Text Available The sense of smell is set apart from other sensory modalities. Odours possess the capacity to trigger immediately strong emotional memories. Moreover, odorous stimuli provide a higher degree of memory retention than other sensory stimuli. Odour perception, even in its most elemental form - olfaction - already involves limbic structures. This early involvement is not paralleled in other sensory modalities. Bearing in mind the considerable connectivity with limbic structures, and the fact that an activation of the amygdala is capable of instantaneously evoking emotions and facilitating the encoding of memories, it is unsurprising that the sense of smell has its characteristic nature. The aim of this review is to analyse current understanding of higher olfactory information processing as it relates to the ability of odours to spontaneously cue highly vivid, affectively toned, and often very old autobiographical memories (episodes known anecdotally as Proust phenomena. Particular emphasis is placed on the diversity of functions attributed to the amygdala. Its role in modulating the encoding and retrieval of long-term memory is investigated with reference to lesion, electrophysiological, immediate early gene, and functional imaging studies in both rodents and humans. Additionally, the influence of hormonal modulation and the adrenergic system on emotional memory storage is outlined. I finish by proposing a schematic of some of the critical neural pathways that underlie the odour-associated encoding and retrieval of emotionally toned autobiographical memories.

Mark Hughes

2004-01-01

162

Errors in nonword repetition: bridging short- and long-term memory  

OpenAIRE

According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep) is a suitable measure of phonological short-term memory for English-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR) as a Portuguese-language version. The objectives of the present study were: i) to investiga...

Santos, F. H.; Bueno, O. F. A.; Gathercole, S. E.

2006-01-01

163

Mind bomb-1 is an essential modulator of long-term memory and synaptic plasticity via the Notch signaling pathway  

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Full Text Available Abstract Background Notch signaling is well recognized as a key regulator of the neuronal fate during embryonic development, but its function in the adult brain is still largely unknown. Mind bomb-1 (Mib1 is an essential positive regulator in the Notch pathway, acting non-autonomously in the signal-sending cells. Therefore, genetic ablation of Mib1 in mature neuron would give valuable insight to understand the cell-to-cell interaction between neurons via Notch signaling for their proper function. Results Here we show that the inactivation of Mib1 in mature neurons in forebrain results in impaired hippocampal dependent spatial memory and contextual fear memory. Consistently, hippocampal slices from Mib1-deficient mice show impaired late-phase, but not early-phase, long-term potentiation and long-term depression without change in basal synaptic transmission at SC-CA1 synapses. Conclusions These data suggest that Mib1-mediated Notch signaling is essential for long-lasting synaptic plasticity and memory formation in the rodent hippocampus.

Yoon Ki-Jun

2012-10-01

164

[Inhibitor influence on conditional food aversion long-term memory retention and reconsolidation in snail].  

Science.gov (United States)

In snails trained for conditional food aversion, the effect of ZIP-protein kinase Mzeta (PKMzeta) inhibitor on mechanisms of memory retention and reconsolidation was studied. It was shown that two days after ZIP injections the dose of 1.25 mg/kg, which were not combined with a reminding procedure, there was no effects, but in dose of 2.5 mg/kg a transient memory impairment after 1 day after the injection with its spontaneous recovery on day 10 was disclosed. ZIP injection in a dose of 5 mg/kg without reminding procedure caused memory impairment and the development of persistent amnesia. During animal repeating training after 11 days after amnesia induction caused by ZIP in dose 5 mg/kg, the number of combined food and reinforcing stimulus needed for memory formation was similar to that seen in the initial training. ZIP in doses of 5 or 10 mg/kg combined with a reminding procedure caused the development of amnesia, however, repeating training after 11 days resulted in a dose-dependent and more rapid formation of memory than in the initial training. It was proposed that in snails trained to conditional food aversion without reminding procedure, inhibition of PKMzeta-like enzyme might cause "erase the memory trace" and in repeating training a new memory was formed. PKMzeta apparently not directly involved in the processes of memory reconsolidation, however, a reminding decreased amnesic effect of ZIP. PMID:25682682

Nikitin, V P; Solntseva, S V; Kozyrev, S A

2014-08-01

165

Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events  

OpenAIRE

Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Partici...

Murayama, Kou; Kitagami, Shinji

2014-01-01

166

EFFECTS OF LONG-TERM MEMANTINE ON MEMORY AND NEUROPATHOLOGY IN TS65DN MICE, A MODEL FOR DOWN SYNDROME  

OpenAIRE

Memantine is a partial NMDA receptor antagonist that has been shown to improve learning and memory in several animal models, and is approved for the treatment of Alzheimer’s disease. Chronic treatments using memantine in animal models of Alzheimer’s disease show disease-modifying effects and suggest a potential neuroprotective function. The present study assessed the effects of both short- and long-term memantine treatment in a mouse model of Down syndrome, the Ts65Dn mouse. The Ts65Dn mo...

Lockrow, Jason; Boger, Heather; Bimonte-nelson, Heather; Granholm, Ann-charlotte

2010-01-01

167

Dopamine interferes with appetitive long-term memory formation in honey bees.  

Science.gov (United States)

Studies in vertebrates and invertebrates have proved the instructive role that different biogenic amines play in the neural representation of rewards and punishments during associative learning. Results from diverse arthropods and using different learning paradigms initially agreed that dopamine (DA) is needed for aversive learning and octopamine (OA) is needed for appetitive learning. However, the notion that both amines constitute separate pathways for appetitive and aversive learning is changing. Here, we asked whether DA, so far only involved in aversive memory formation in honey bees, does also modulate appetitive memory. Using the well characterized appetitive olfactory conditioning of the proboscis extension reflex (PER), we show that DA impairs appetitive memory consolidation. In addition, we found that blocking DA receptors enhances appetitive memory. These results are consistent with the view that aversive and appetitive components interact during learning and memory formation to ensure adaptive behavior. PMID:24076013

Klappenbach, Martín; Kaczer, Laura; Locatelli, Fernando

2013-11-01

168

Eliminating finite-size effects and detecting the amount of white noise in short records with long-term memory  

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Long-term memory is ubiquitous in nature and has important consequences for the occurrence of natural hazards, but its detection often is complicated by the short length of the considered records and additive white noise in the data. Here we study synthetic Gaussian distributed records xi of length N that consist of a long-term correlated component (1-a)yi characterized by a correlation exponent ? , 00)=Bas-? , and Ea={2Ba/[(2-?)(1-?)]}N-?+O(N-1) . The finite-size parameter Ea also occurs in related quantities, for example, in the variance ?N2(s) of the local mean in time windows of length s : ?N2(s)=[??2(s)-Ea]/(1-Ea) . For purely long-term correlated data B0?(2-?)(1-?)/2 yielding E0?N-? , and thus CN(s)=[((2-?)(1-?))/(2)s-?-N-?]/[1-N-?] and ?N2(s)=[s-?-N-?]/[1-N-?] . We show how to estimate Ea and C?(s) from a given data set and thus how to obtain accurately the exponent ? and the amount of white noise a .

Lennartz, Sabine; Bunde, Armin

2009-06-01

169

Long-Term Heavy Ketamine Use is Associated with Spatial Memory Impairment and Altered Hippocampal Activation  

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Ketamine, a non-competitive N-methyl-d-aspartate receptor antagonist, is rising in popularity as a drug of abuse. Preliminary evidence suggests that chronic, heavy ketamine use may have profound effects on spatial memory but the mechanism of these deficits is as yet unclear. This study aimed to examine the neural mechanism by which heavy ketamine use impairs spatial memory processing. In a sample of 11 frequent ketamine users and 15 poly-drug controls, matched for IQ, age, years in education. We used fMRI utilizing an ROI approach to examine the neural activity of three regions known to support successful navigation; the hippocampus, parahippocampal gyrus, and the caudate nucleus during a virtual reality task of spatial memory. Frequent ketamine users displayed spatial memory deficits, accompanied by and related to, reduced activation in both the right hippocampus and left parahippocampal gyrus during navigation from memory, and in the left caudate during memory updating, compared to controls. Ketamine users also exhibited schizotypal and dissociative symptoms that were related to hippocampal activation. Impairments in spatial memory observed in ketamine users are related to changes in medial temporal lobe activation. Disrupted medial temporal lobe function may be a consequence of chronic ketamine abuse and may relate to schizophrenia-like symptomatology observed in ketamine users. PMID:25538631

Morgan, Celia J. A.; Dodds, Chris M.; Furby, Hannah; Pepper, Fiona; Fam, Johnson; Freeman, Tom P.; Hughes, Emer; Doeller, Christian; King, John; Howes, Oliver; Stone, James M.

2014-01-01

170

Errors in nonword repetition: bridging short- and long-term memory  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english According to the working memory model, the phonological loop is the component of working memory specialized in processing and manipulating limited amounts of speech-based information. The Children's Test of Nonword Repetition (CNRep) is a suitable measure of phonological short-term memory for Englis [...] h-speaking children, which was validated by the Brazilian Children's Test of Pseudoword Repetition (BCPR) as a Portuguese-language version. The objectives of the present study were: i) to investigate developmental aspects of the phonological memory processing by error analysis in the nonword repetition task, and ii) to examine phoneme (substitution, omission and addition) and order (migration) errors made in the BCPR by 180 normal Brazilian children of both sexes aged 4-10, from preschool to 4th grade. The dominant error was substitution [F(3,525) = 180.47; P

F.H., Santos; O.F.A., Bueno; S.E., Gathercole.

2006-03-01

171

Consolidation power of extrinsic rewards: reward cues enhance long-term memory for irrelevant past events.  

Science.gov (United States)

Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward. PMID:23421444

Murayama, Kou; Kitagami, Shinji

2014-02-01

172

Interacting Memory Systems—Does EEG Alpha Activity Respond to Semantic Long-Term Memory Access in a Working Memory Task?  

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Full Text Available Memory consists of various individual processes which form a dynamic system co-ordinated by central (executive functions. The episodic buffer as direct interface between episodic long-term memory (LTM and working memory (WM is fairly well studied but such direct interaction is less clear in semantic LTM. Here, we designed a verbal delayed-match-to-sample task specifically to differentiate between pure information maintenance and mental manipulation of memory traces with and without involvement of access to semantic LTM. Task-related amplitude differences of electroencephalographic (EEG oscillatory brain activity showed a linear increase in frontal-midline theta and linear suppression of parietal beta amplitudes relative to memory operation complexity. Amplitude suppression at upper alpha frequency, which was previously found to indicate access to semantic LTM, was only sensitive to mental manipulation in general, irrespective of LTM involvement. This suggests that suppression of upper EEG alpha activity might rather reflect unspecific distributed cortical activation during complex mental processes than accessing semantic LTM.

Barbara Berger

2014-12-01

173

Long-term habituation (LTH) in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory  

Scientific Electronic Library Online (English)

Full Text Available A decade of studies on long-term habituation (LTH) in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed [...] context, stimulus frequency and circadian phase specificity. A strong training protocol (STP) (³15 trials, intertrial interval (ITI) of 171 s) invariably yielded LTH, while a weak training protocol (WTP) (£10 trials, ITI = 171 s) invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA) activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining). The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

H., Maldonado; A., Romano; D., Tomsic.

1997-07-01

174

Long-term habituation (LTH in the crab Chasmagnathus: a model for behavioral and mechanistic studies of memory  

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Full Text Available A decade of studies on long-term habituation (LTH in the crab Chasmagnathus is reviewed. Upon sudden presentation of a passing object overhead, the crab reacts with an escape response that habituates promptly and for at least five days. LTH proved to be an instance of associative memory and showed context, stimulus frequency and circadian phase specificity. A strong training protocol (STP (³15 trials, intertrial interval (ITI of 171 s invariably yielded LTH, while a weak training protocol (WTP (£10 trials, ITI = 171 s invariably failed. STP was used with a presumably amnestic agent and WTP with a presumably hypermnestic agent. Remarkably, systemic administration of low doses was effective, which is likely to be due to the lack of an endothelial blood-brain barrier. LTH was blocked by inhibitors of protein and RNA synthesis, enhanced by protein kinase A (PKA activators and reduced by PKA inhibitors, facilitated by angiotensin II and IV and disrupted by saralasin. The presence of angiotensins and related compounds in the crab brain was demonstrated. Diverse results suggest that LTH includes two components: an initial memory produced by spaced training and mainly expressed at an initial phase of testing, and a retraining memory produced by massed training and expressed at a later phase of testing (retraining. The initial memory would be associative, context specific and sensitive to cycloheximide, while the retraining memory would be nonassociative, context independent and insensitive to cycloheximide

Maldonado H.

1997-01-01

175

Retroactive interference of object-in-context long-term memory: role of dorsal hippocampus and medial prefrontal cortex.  

Science.gov (United States)

Retroactive interference (RI) is a type of amnesia in which a new learning experience can impair the expression of a previous one. It has been studied in several types of memories for over a century. Here, we aimed to study in the long-term memory (LTM) formation of an object-in-context task, defined as the recognition of a familiar object in a context different to that in which it was previously encountered. We trained rats with two sample trials, each taking place in a different context in association with different objects. Test sessions were performed 24 h later, to evaluate LTM for both object-context pairs using separate groups of trained rats. Furthermore, given the involvement of hippocampus (Hp) and medial prefrontal cortex (mPFC) in several recognition memories, we also analyzed the participation of these structures in the LTM formation of this task by the local infusion of muscimol. Our results show that object-in-context LTM formation is sensitive to RI by a different either familiar or novel object-context pair trial, experienced 1 h later. This interference occurs in a restricted temporal window and works on the LTM consolidation phase, leaving intact short-term memory expression. The second sample trial did not affect the object recognition part of the memory. Besides, muscimol treatment before the second sample trial blocks its object-in-context LTM and restores the first sample trial memory. We hypothesized that LTM-RI amnesia is probably caused by resources or cellular machinery competition in these brain regions when they are engaged in memory formation of the traces. In sum, when two different object-in-context memory traces are being processed, the second trace interferes with the consolidation of the first one requiring mPFC and CA1 dorsal Hp activation. PMID:25044872

Martínez, María Cecilia; Villar, María Eugenia; Ballarini, Fabricio; Viola, Haydée

2014-12-01

176

Lead (Pb+2) impairs long-term memory and blocks learning-induced increases in hippocampal protein kinase C activity  

International Nuclear Information System (INIS)

The long-term storage of information in the brain known as long-term memory (LTM) depends on a variety of intracellular signaling cascades utilizing calcium (Ca2+) and cyclic adenosine monophosphate as second messengers. In particular, Ca+2/phospholipid-dependent protein kinase C (PKC) activity has been proposed to be necessary for the transition from short-term memory to LTM. Because the neurobehavioral toxicity of lead (Pb+2) has been associated to its interference with normal Ca+2 signaling in neurons, we studied its effects on spatial learning and memory using a hippocampal-dependent discrimination task. Adult rats received microinfusions of either Na+ or Pb+2 acetate in the CA1 hippocampal subregion before each one of four training sessions. A retention test was given 7 days later to examine LTM. Results suggest that intrahippocampal Pb+2 did not affect learning of the task, but significantly impaired retention. The effects of Pb+2 selectively impaired reference memory measured in the retention test, but had no effect on the general performance because it did not affect the latency to complete the task during the test. Finally, we examined the effects of Pb+2 on the induction of hippocampal Ca+2/phospholipid-dependent PKC activity during acquisition training. The results showed that Pb+2 interfered with the learning-induced activation of Ca+2/phospholipid-dependent PKC on day 3 of acquisition. Overall, our results indicate that Pb+2 causes cognitive impairments in adult rats and that such effects might be subserved by interference with Ca+2-related signaling mechanisms required for normal LTM

177

Mechanisms of amnesia induced by impairment of long-term memory reconsolidation in edible snail.  

Science.gov (United States)

Involvement of neurotransmitter receptors and translation and transcription processes in reconsolidation of conditioned food aversion memory was investigated in experiments on edible snails. Injections of neurotransmitter receptor antagonists and protein synthesis inhibitors before the reminder session were found to induce amnesia that was characterized by the possibility of memory recovery in repeated training and under the effect of mnemotropic agent D-cycloserine (early stage of amnesia) or by resistance to the mentioned actions (late stage). It has been shown that amnesia induction by memory reconsolidation impairment by neurotransmitter receptor antagonists depends on synthesis of specific proteins and mRNA, similar to the cases of induction of other adaptive brain modifications. PMID:23113237

Nikitin, V P; Solntseva, S V

2012-09-01

178

DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment.  

Science.gov (United States)

Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. We also investigated how the neural processing of appetitive and aversive motivation and episodic memory were modulated by dopaminergic mechanisms. To that end, participants were selected on the basis of their genotype for a variable number of tandem repeat polymorphism of the dopamine transporter (DAT) gene. The resulting groups were carefully matched for the 5-HTTLPR polymorphism of the serotonin transporter gene. Recognition memory for cues from both motivational categories was enhanced in participants homozygous for the 10-repeat allele of the DAT, the functional effects of which are not known yet, but not in heterozygous subjects. In comparison with heterozygous participants, 10-repeat homozygous participants also showed increased striatal activity for anticipation of motivational outcomes compared to neutral outcomes. In a subsequent memory analysis, encoding activity in striatum and hippocampus was found to be higher for later recognized items in 10-repeat homozygotes compared to 9/10-repeat heterozygotes. These findings suggest that processing of appetitive and aversive motivation in the human striatum involve the dopaminergic system and that dopamine plays a role in memory for both types of motivational information. In accordance with animal studies, these data support the idea that encoding of motivational events depends on dopaminergic processes in the hippocampus. PMID:23911780

Wittmann, Bianca C; Tan, Geoffrey C; Lisman, John E; Dolan, Raymond J; Düzel, Emrah

2013-09-01

179

Reprint of: DAT genotype modulates striatal processing and long-term memory for items associated with reward and punishment.  

Science.gov (United States)

Previous studies have shown that appetitive motivation enhances episodic memory formation via a network including the substantia nigra/ventral tegmental area (SN/VTA), striatum and hippocampus. This functional magnetic resonance imaging (fMRI) study now contrasted the impact of aversive and appetitive motivation on episodic long-term memory. Cue pictures predicted monetary reward or punishment in alternating experimental blocks. One day later, episodic memory for the cue pictures was tested. We also investigated how the neural processing of appetitive and aversive motivation and episodic memory were modulated by dopaminergic mechanisms. To that end, participants were selected on the basis of their genotype for a variable number of tandem repeat polymorphism of the dopamine transporter (DAT) gene. The resulting groups were carefully matched for the 5-HTTLPR polymorphism of the serotonin transporter gene. Recognition memory for cues from both motivational categories was enhanced in participants homozygous for the 10-repeat allele of the DAT, the functional effects of which are not known yet, but not in heterozygous subjects. In comparison with heterozygous participants, 10-repeat homozygous participants also showed increased striatal activity for anticipation of motivational outcomes compared to neutral outcomes. In a subsequent memory analysis, encoding activity in striatum and hippocampus was found to be higher for later recognized items in 10-repeat homozygotes compared to 9/10-repeat heterozygotes. These findings suggest that processing of appetitive and aversive motivation in the human striatum involve the dopaminergic system and that dopamine plays a role in memory for both types of motivational information. In accordance with animal studies, these data support the idea that encoding of motivational events depends on dopaminergic processes in the hippocampus. PMID:24139823

Wittmann, Bianca C; Tan, Geoffrey C; Lisman, John E; Dolan, Raymond J; Düzel, Emrah

2013-10-01

180

ROLE OF NEUROTRANSMITTERS AND PROTEIN SYNTHESIS IN SHORT- AND LONG-TERM MEMORY  

Energy Technology Data Exchange (ETDEWEB)

Anisomycin is an effective inhibitor of cerebral protein synthesis in mice and is also an effective amnestic agent for both passive and active behavioral tasks. From use of anisomycin in combination with a variety of stimulant and depressant drugs, we conclude that the level of arousal following acquisition plays an important role in determining the duration and the rate of the biosynthetic phase of memory formation. While we have interpreted the experiments with anisomycin as evidence for an essential role of protein in memory storage, others have suggested that side effects of inhibitors of protein synthesis on catecholamine metabolism are the main cause of amnesia. Several experiments were therefore done to compare the effects of anisemycin and catecholamine inhibitors on memory. We conclude that anisomycin's principal amnestic mechanism does not involve inhibition of the catecholamine system. The results strengthen our conclusion that protein synthesis is an essential component for longterm memory trace formation. Also, it is suggested that proteins synthesized in the neuronal cell body are used, in conjunction with other molecules, to produce permanent and semi-permanent anatomical changes.

Bennett, E.L.; Rosenzweig, M.R.; Flood, J.F.

1978-10-01

181

Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"  

Science.gov (United States)

The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

Amano, Hisayuki; Maruyama, Ichiro N.

2011-01-01

182

Long-term avoidance memory formation is associated with a transient increase in mushroom body synaptic complexes in leaf-cutting ants  

Science.gov (United States)

Long-term behavioral changes related to learning and experience have been shown to be associated with structural remodeling in the brain. Leaf-cutting ants learn to avoid previously preferred plants after they have proved harmful for their symbiotic fungus, a process that involves long-term olfactory memory. We studied the dynamics of brain microarchitectural changes after long-term olfactory memory formation following avoidance learning in Acromyrmex ambiguus. After performing experiments to control for possible neuronal changes related to age and body size, we quantified synaptic complexes (microglomeruli, MG) in olfactory regions of the mushroom bodies (MBs) at different times after learning. Long-term avoidance memory formation was associated with a transient change in MG densities. Two days after learning, MG density was higher than before learning. At days 4 and 15 after learning—when ants still showed plant avoidance—MG densities had decreased to the initial state. The structural reorganization of MG triggered by long-term avoidance memory formation clearly differed from changes promoted by pure exposure to and collection of novel plants with distinct odors. Sensory exposure by the simultaneous collection of several, instead of one, non-harmful plant species resulted in a decrease in MG densities in the olfactory lip. We hypothesize that while sensory exposure leads to MG pruning in the MB olfactory lip, the formation of long-term avoidance memory involves an initial growth of new MG followed by subsequent pruning. PMID:25904854

Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

2015-01-01

183

Post ischemia intermittent hypoxia induces hippocampal neurogenesis and synaptic alterations and alleviates long-term memory impairment.  

Science.gov (United States)

Adult hippocampal neurogenesis is important for learning and memory, especially after a brain injury such as ischemia. Newborn hippocampal neurons contribute to memory performance by establishing functional synapses with target cells. This study demonstrated that the maturation of hippocampal neurons is enhanced by postischemia intermittent hypoxia (IH) intervention. The effects of IH intervention in cultured neurons were mediated by increased synaptogenesis, which was primarily regulated by brain-derived neurotrophic factor (BDNF)/PI3K/AKT. Hippocampal neo-neurons expressed BDNF and exhibited enhanced presynaptic function as indicated by increases in the pSynapsin expression, synaptophysin intensity, and postsynapse density following IH intervention after ischemia. Postischemia IH-induced hippocampal neo-neurons were affected by presynaptic activity, which reflected the dynamic plasticity of the glutamatergic receptors. These alterations were also associated with the alleviation of ischemia-induced long-term memory impairment. Our results suggest that postischemia IH intervention rescued ischemia-induced spatial learning and memory impairment by inducing hippocampal neurogenesis and functional synaptogenesis via BDNF expression. PMID:23443175

Tsai, Yi-Wei; Yang, Yea-Ru; Sun, Synthia H; Liang, Keng-Chen; Wang, Ray-Yau

2013-05-01

184

Hippocampal inactivation with TTX impairs long-term spatial memory retrieval and modifies brain metabolic activity.  

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Functional inactivation techniques enable studying the hippocampal involvement in each phase of spatial memory formation in the rat. In this study, we applied tetrodotoxin unilaterally or bilaterally into the dorsal hippocampus to evaluate the role of this brain structure in retrieval of memories acquired 28 days before in the Morris water maze. We combined hippocampal inactivation with the assessment of brain metabolism using cytochrome oxidase histochemistry. Several brain regions were considered, including the hippocampus and other related structures. Results showed that both unilateral and bilateral hippocampal inactivation impaired spatial memory retrieval. Hence, whereas subjects with bilateral hippocampal inactivation showed a circular swim pattern at the side walls of the pool, unilateral inactivation favoured swimming in the quadrants adjacent to the target one. Analysis of cytochrome oxidase activity disclosed regional differences according to the degree of hippocampal functional blockade. In comparison to control group, animals with bilateral inactivation showed increased CO activity in CA1 and CA3 areas of the hippocampus during retrieval, while the activity of the dentate gyrus substantially decreased. However, unilateral inactivated animals showed decreased CO activity in Ammon's horn and the dentate gyrus. This study demonstrated that retrieval recruits differentially the hippocampal subregions and the balance between them is altered with hippocampal functional lesions. PMID:23724089

Conejo, Nélida María; Cimadevilla, José Manuel; González-Pardo, Héctor; Méndez-Couz, Marta; Arias, Jorge Luis

2013-01-01

185

Disruption of long-term alcohol-related memory reconsolidation: Role of ?-adrenoceptors and NMDA receptors  

Directory of Open Access Journals (Sweden)

Full Text Available Disrupting reconsolidation of drug-related memories may be effective in reducing the incidence of relapse. In the current study we examine whether alcohol- related memories are prone to disruption by the ? -adrenergicreceptor antagonist propranolol (10 mg/kg and the NMDA receptor antagonist MK801 (0.1 mg/kg following their reactivation. In operant chambers, male Wistar rats were trained to self-administer a 12% alcohol solution. After 3 weeks of abstinence, the animals were placed in the self-administration cages and were reexposed to the alcohol-associated cues for a 20-min retrieval period, immediately followed by a systemic injection of either propranolol, MK801 or saline. Rats were tested for cue-induced alcohol seeking on the following day. Retrieval session, injection and test were repeated on 2 further occasions at weekly intervals. Both propranolol and MK801 administration upon reactivation did not reduce alcohol seeking after the first reactivation test. However, a significant reduction of alcohol seeking was observed over three post-training tests in propranolol treated animals, and MK801 treated animals showed a strong tendency towards reduced alcohol seeking (p=0.06. Our data indicate that reconsolidation of alcohol-related memories can be disrupted after a long post-training interval and that particularly ?-adrenergic receptors may represent novel targets for pharmacotherapy of alcoholism, in combination with cue-exposure therapies.

JelteAWouda

2010-11-01

186

A role for the insular cortex in long-term memory for context-evoked drug craving in rats.  

Science.gov (United States)

Drug craving critically depends on the function of the interoceptive insular cortex, and may be triggered by contextual cues. However, the role of the insula in the long-term memory linking context with drug craving remains unknown. Such a memory trace probably resides in some neocortical region, much like other declarative memories. Studies in humans and rats suggest that the insula may include such a region. Rats chronically implanted with bilateral injection cannulae into the high-order rostral agranular insular cortex (RAIC) or the primary interoceptive posterior insula (pIC) were conditioned to prefer the initially aversive compartment of a 2-compartment place preference apparatus by repeatedly pairing it to amphetamine. We found a reversible but long-lasting loss (ca. 24 days) of amphetamine-conditioned place preference (CPP) and a decreased expression in the insula of zif268, a crucial protein in memory reconsolidation, when anisomycin (ANI) was microinjected into the RAIC immediately after the reactivation of the conditioned amphetamine/context memory. ANI infusion into the RAIC without reactivation did not change CPP, whereas ANI infusion into pIC plus caused a 15 days loss of CPP. We also found a 24 days loss of CPP when we reversibly inactivated pIC during extinction trials. We interpret these findings as evidence that the insular cortex, including the RAIC, is involved in a context/drug effect association. These results add a drug-related memory function to the insular cortex to the previously found role of the pIC in the perception of craving or malaise. PMID:22534623

Contreras, Marco; Billeke, Pablo; Vicencio, Sergio; Madrid, Carlos; Perdomo, Guetón; González, Marcela; Torrealba, Fernando

2012-08-01

187

Impaired long-term memory retention and working memory in sdy mutant mice with a deletion in Dtnbp1, a susceptibility gene for schizophrenia  

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Full Text Available Abstract Background Schizophrenia is a complex genetic disorder caused by multiple genetic and environmental factors. The dystrobrevin-binding protein 1 (DTNBP1: dysbindin-1 gene is a major susceptibility gene for schizophrenia. Genetic variations in DTNBP1 are associated with cognitive functions, general cognitive ability and memory function, and clinical features of patients with schizophrenia including negative symptoms and cognitive decline. Since reduced expression of dysbindin-1 has been observed in postmortem brains of patients with schizophrenia, the sandy (sdy mouse, which has a deletion in the Dtnbp1 gene and expresses no dysbindin-1 protein, could be an animal model of schizophrenia. To address this issue, we have carried out a comprehensive behavioral analysis of the sdy mouse in this study. Results In a rotarod test, sdy mice did not exhibit motor learning whilst the wild type mice did. In a Barnes circular maze test both sdy mice and wild type mice learned to selectively locate the escape hole during the course of the training period and in the probe trial conducted 24 hours after last training. However, sdy mice did not locate the correct hole in the retention probe tests 7 days after the last training trial, whereas wild type mice did, indicating impaired long-term memory retention. A T-maze forced alternation task, a task of working memory, revealed no effect of training in sdy mice despite the obvious effect of training in wild type mice, suggesting a working memory deficit. Conclusion Sdy mouse showed impaired long-term memory retention and working memory. Since genetic variation in DTNBP1 is associated with both schizophrenia and memory function, and memory function is compromised in patients with schizophrenia, the sdy mouse may represent a useful animal model to investigate the mechanisms of memory dysfunction in the disorder.

Takao Keizo

2008-10-01

188

Potent induction of long-term CD8+ T cell memory by short-term IL-4 exposure during T cell receptor stimulation  

OpenAIRE

An important goal of vaccination is to achieve long-term survival of functional memory T cells. Using a MHC-compatible adoptive transfer system, we show here that a short, 3-day IL-4 but not IL-2 or IL-12 exposure during in vitro T cell receptor stimulation of naive CD8+ T cells induced long-lasting in vivo memory. Such long-term memory CD8+ T cells expressed antigen-specific cytotoxicity and the potential for IFN-? and IL-4 production. Our results support the concept that functional T cell ...

Huang, Li-rung; Chen, Fen-ling; Chen, Yi-ting; Lin, Ya-min; Kung, John T.

2000-01-01

189

c-Rel, an NF-[kappa]B Family Transcription Factor, Is Required for Hippocampal Long-Term Synaptic Plasticity and Memory Formation  

Science.gov (United States)

Transcription is a critical component for consolidation of long-term memory. However, relatively few transcriptional mechanisms have been identified for the regulation of gene expression in memory formation. In the current study, we investigated the activity of one specific member of the NF-[kappa]B transcription factor family, c-Rel, during…

Ahn, Hyung Jin; Hernandez, Caterina M.; Levenson, Jonathan M.; Lubin, Farah D.; Liou, Hsiou-Chi; Sweatt, J. David

2008-01-01

190

A Dynamical Model for Information Retrieval and Emergence of Scale-Free Clusters in a Long Term Memory Network  

CERN Document Server

The classical forms of knowledge representation fail when a strong dynamical interconnection between system and environment comes into play. We propose here a model of information retrieval derived from the Kintsch-Ericsson scheme, based upon a long term memory (LTM) associative net whose structure changes in time according to the textual content of the analyzed documents. Both the theoretical analysis carried out by using simple statistical tools and the tests show the appearing of typical power-laws and the net configuration as a scale-free graph. The information retrieval from LTM shows that the entire system can be considered to be an information amplifier which leads to the emergence of new cognitive structures. It has to be underlined that the expanding of the semantic domain regards the user-network as a whole system.

Licata, Ignazio

2010-01-01

191

Effects of Long-Term Exercise on Spatial Learning, Memory Ability, and Cortical Capillaries in Aged Rats  

Science.gov (United States)

Background This study aimed to determine the effects of long-term running exercise on spatial learning, spatial memory, and cortical capillaries in aged rats. Material/Methods Fourteen-month-old female and male Sprague-Dawley rats were randomly divided into an exercised group (EG) and a non-exercised group (NG). The EG rats were trained on treadmill running for 4 or 14 months. The NG rats were housed under identical conditions without running. Spatial learning and memory were assessed with the Morris water maze. The cortical capillary parameters were quantitatively investigated using immunohistochemical and stereological methods. Results The escaped latencies of the EG were significantly different from those of the NG in 18-month-old females and 28-month-old males (p0.05). In 28-month-old female rats, stereological techniques showed significant differences between the EG and NG in the cortical capillary volume (median, 22.55 vs. 11.42, pspatial learning, memory capacity and cortical capillaries in aged rats. PMID:25828032

Wang, Sanrong; Chen, Lin; Zhang, Lei; Huang, Chunxia; Xiu, Yun; Wang, Feifei; Zhou, Chunni; Luo, Yanmin; Xiao, Qian; Tang, Yong

2015-01-01

192

Long-term social recognition memory in adult male rats: factor analysis of the social and non-social behaviors  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english A modified version of the intruder-resident paradigm was used to investigate if social recognition memory lasts at least 24 h. One hundred and forty-six adult male Wistar rats were used. Independent groups of rats were exposed to an intruder for 0.083, 0.5, 2, 24, or 168 h and tested 24 h after the [...] first encounter with the familiar or a different conspecific. Factor analysis was employed to identify associations between behaviors and treatments. Resident rats exhibited a 24-h social recognition memory, as indicated by a 3- to 5-fold decrease in social behaviors in the second encounter with the same conspecific compared to those observed for a different conspecific, when the duration of the first encounter was 2 h or longer. It was possible to distinguish between two different categories of social behaviors and their expression depended on the duration of the first encounter. Sniffing the anogenital area (49.9% of the social behaviors), sniffing the body (17.9%), sniffing the head (3%), and following the conspecific (3.1%), exhibited mostly by resident rats, characterized social investigation and revealed long-term social recognition memory. However, dominance (23.8%) and mild aggression (2.3%), exhibited by both resident and intruders, characterized social agonistic behaviors and were not affected by memory. Differently, sniffing the environment (76.8% of the non-social behaviors) and rearing (14.3%), both exhibited mostly by adult intruder rats, characterized non-social behaviors. Together, these results show that social recognition memory in rats may last at least 24 h after a 2-h or longer exposure to the conspecific.

P.J., Moura; S.T., Meirelles; G.F., Xavier.

2010-07-01

193

Access to long-term optical memories using photon echoes retrieved from semiconductor spins  

Science.gov (United States)

The ability to store optical information is important for both classical and quantum communication. Achieving this in a comprehensive manner (converting the optical field into material excitation, storing this excitation, and releasing it after a controllable time delay) is greatly complicated by the many, often conflicting, properties of the material. More specifically, optical resonances in semiconductor quantum structures with high oscillator strength are inevitably characterized by short excitation lifetimes (and, therefore, short optical memory). Here, we present a new experimental approach to stimulated photon echoes by transferring the information contained in the optical field into a spin system, where it is decoupled from the optical vacuum field and may persist much longer. We demonstrate this for an n-doped CdTe/(Cd,Mg)Te quantum well, the storage time of which could be increased by more than three orders of magnitude, from the picosecond range up to tens of nanoseconds.

Langer, L.; Poltavtsev, S. V.; Yugova, I. A.; Salewski, M.; Yakovlev, D. R.; Karczewski, G.; Wojtowicz, T.; Akimov, I. A.; Bayer, M.

2014-11-01

194

Differential Roles for "Nr4a1" and "Nr4a2" in Object Location vs. Object Recognition Long-Term Memory  

Science.gov (United States)

"Nr4a1" and "Nr4a2" are transcription factors and immediate early genes belonging to the nuclear receptor Nr4a family. In this study, we examine their role in long-term memory formation for object location and object recognition. Using siRNA to block expression of either "Nr4a1" or "Nr4a2", we found that "Nr4a2" is necessary for both long-term

McNulty, Susan E.; Barrett, Ruth M.; Vogel-Ciernia, Annie; Malvaez, Melissa; Hernandez, Nicole; Davatolhagh, M. Felicia; Matheos, Dina P.; Schiffman, Aaron; Wood, Marcelo A.

2012-01-01

195

Can we throw information out of visual working memory and does this leave informational residue in long-term memory?  

OpenAIRE

Can we entirely erase a temporary memory representation from mind? This question has been addressed in several recent studies that tested the specific hypothesis that a representation can be erased from visual working memory based on a cue that indicated that the representation was no longer necessary for the task. In addition to behavioral results that are consistent with the idea that we can throw information out of visual working memory, recent neurophysiological recordings support this pr...

AshleighMonetteMaxcey; GeoffreyF.Woodman

2014-01-01

196

Participation of the Classical Speech Areas in Auditory Long-Term Memory  

Science.gov (United States)

Accumulating evidence suggests that storing speech sounds requires transposing rapidly fluctuating sound waves into more easily encoded oromotor sequences. If so, then the classical speech areas in the caudalmost portion of the temporal gyrus (pSTG) and in the inferior frontal gyrus (IFG) may be critical for performing this acoustic-oromotor transposition. We tested this proposal by applying repetitive transcranial magnetic stimulation (rTMS) to each of these left-hemisphere loci, as well as to a nonspeech locus, while participants listened to pseudowords. After 5 minutes these stimuli were re-presented together with new ones in a recognition test. Compared to control-site stimulation, pSTG stimulation produced a highly significant increase in recognition error rate, without affecting reaction time. By contrast, IFG stimulation led only to a weak, non-significant, trend toward recognition memory impairment. Importantly, the impairment after pSTG stimulation was not due to interference with perception, since the same stimulation failed to affect pseudoword discrimination examined with short interstimulus intervals. Our findings suggest that pSTG is essential for transforming speech sounds into stored motor plans for reproducing the sound. Whether or not the IFG also plays a role in speech-sound recognition could not be determined from the present results. PMID:25815813

Karabanov, Anke Ninija; Paine, Rainer; Chao, Chi Chao; Schulze, Katrin; Scott, Brian; Hallett, Mark; Mishkin, Mortimer

2015-01-01

197

Participation of the classical speech areas in auditory long-term memory.  

Science.gov (United States)

Accumulating evidence suggests that storing speech sounds requires transposing rapidly fluctuating sound waves into more easily encoded oromotor sequences. If so, then the classical speech areas in the caudalmost portion of the temporal gyrus (pSTG) and in the inferior frontal gyrus (IFG) may be critical for performing this acoustic-oromotor transposition. We tested this proposal by applying repetitive transcranial magnetic stimulation (rTMS) to each of these left-hemisphere loci, as well as to a nonspeech locus, while participants listened to pseudowords. After 5 minutes these stimuli were re-presented together with new ones in a recognition test. Compared to control-site stimulation, pSTG stimulation produced a highly significant increase in recognition error rate, without affecting reaction time. By contrast, IFG stimulation led only to a weak, non-significant, trend toward recognition memory impairment. Importantly, the impairment after pSTG stimulation was not due to interference with perception, since the same stimulation failed to affect pseudoword discrimination examined with short interstimulus intervals. Our findings suggest that pSTG is essential for transforming speech sounds into stored motor plans for reproducing the sound. Whether or not the IFG also plays a role in speech-sound recognition could not be determined from the present results. PMID:25815813

Karabanov, Anke Ninija; Paine, Rainer; Chao, Chi Chao; Schulze, Katrin; Scott, Brian; Hallett, Mark; Mishkin, Mortimer

2015-01-01

198

Double-strand breaks and the concept of short- and long-term epigenetic memory.  

Science.gov (United States)

Double-strand breaks represent an extremely cytolethal form of DNA damage and thus pose a serious threat to the preservation of genetic and epigenetic information. Though it is well-known that double-strand breaks such as those generated by ionising radiation are among the principal causative factors behind mutations, chromosomal aberrations, genetic instability and carcinogenesis, significantly less is known about the epigenetic consequences of double-strand break formation and repair for carcinogenesis. Double-strand break repair is a highly coordinated process that requires the unravelling of the compacted chromatin structure to facilitate repair machinery access and then restoration of the original undamaged chromatin state. Recent experimental findings have pointed to a potential mechanism for double-strand break-induced epigenetic silencing. This review will discuss some of the key epigenetic regulatory processes involved in double-strand break (DSB) repair and how incomplete or incorrect restoration of chromatin structure can leave a DSB-induced epigenetic memory of damage with potentially pathological repercussions. PMID:21174214

Orlowski, Christian; Mah, Li-Jeen; Vasireddy, Raja S; El-Osta, Assam; Karagiannis, Tom C

2011-04-01

199

Technical Note: Long-term memory effect in the atmospheric CO2 concentration at Mauna Loa  

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Full Text Available The monthly mean values of the atmospheric carbon dioxide concentration derived from in-situ air samples collected at Mauna Loa Observatory, Hawaii, USA during 1958–2004 (the longest continuous record available in the world are analyzed by employing the detrended fluctuation analysis to detect scaling behavior in this time series. The main result is that the fluctuations of carbon dioxide concentrations exhibit long-range power-law correlations (long memory with lag times ranging from four months to eleven years, which correspond to 1/f noise. This result indicates that random perturbations in the carbon dioxide concentrations give rise to noise, characterized by a frequency spectrum following a power-law with exponent that approaches to one; the latter shows that the correlation times grow strongly. This feature is pointing out that a correctly rescaled subset of the original time series of the carbon dioxide concentrations resembles the original time series. Finally, the power-law relationship derived from the real measurements of the carbon dioxide concentrations could also serve as a tool to improve the confidence of the atmospheric chemistry-transport and global climate models.

C. Varotsos

2007-01-01

200

Technical Note: Long-term memory effect in the atmospheric CO2 concentration at Mauna Loa  

Directory of Open Access Journals (Sweden)

Full Text Available The monthly mean values of the atmospheric carbon dioxide concentration derived from in-situ air samples collected at Mauna Loa Observatory, Hawaii, during 1958–2004 (the longest continuous record available in the world are analyzed by employing the detrended fluctuation analysis to detect scaling behavior in this time series. The main result is that the fluctuations of carbon dioxide concentrations exhibit long-range power-law correlations (long memory with lag times ranging from four months to eleven years, which correspond to 1/f noise. This result indicates that random perturbations in the carbon dioxide concentrations give rise to noise, characterized by a frequency spectrum following a power-law with exponent that approaches to one; the latter shows that the correlation times grow strongly. This feature is pointing out that a correctly rescaled subset of the original time series of the carbon dioxide concentrations resembles the original time series. Finally, the power-law relationship derived from the real measurements of the carbon dioxide concentrations could also serve as a tool to improve the confidence of the atmospheric chemistry-transport and global climate models.

M. Efstathiou

2006-11-01

201

D-cycloserine prevents relational memory deficits and suppression of long-term potentiation induced by scopolamine in the hippocampus.  

Science.gov (United States)

Previous research has demonstrated that systemic D-cycloserine (DCS), a partial agonist of the N-methyl-D-aspartate receptor (NMDAR), enhances memory processes in different learning paradigms and attenuates mnemonic deficits produced by diverse pharmacological manipulations. In the present study two experiments were conducted in rats to investigate whether DCS administered in the hippocampus may rescue relational memory deficits and improve deficient synaptic plasticity, both induced by an intracerebral injection of the muscarinic receptor antagonist scopolamine (SCOP). In experiment 1, we assessed whether DCS would prevent SCOP-induced amnesia in an olfactory learning paradigm requiring the integrity of the cholinergic system, the social transmission of food preference (STFP). The results showed that DCS (10 ?g/site) injected into the ventral hippocampus (vHPC) before STFP acquisition compensated the 24-h retention deficit elicited by post-training intra-vHPC SCOP (40 ?g/site), although it did not affect memory expression in non-SCOP treated rats. In experiment 2, we evaluated whether the perfusion of DCS in hippocampal slices may potentiate synaptic plasticity in CA1 synapses and thus recover SCOP-induced deficits in long-term potentiation (LTP). We found that DCS (50 µM and 100 µM) was able to rescue SCOP (100 µM)-induced LTP maintenance impairment, in agreement with the behavioral findings. Additionally, DCS alone (50 µM and 100 µM) enhanced field excitatory postsynaptic potentials prior to high frequency stimulation, although it did not significantly potentiate LTP. Our results suggest that positive modulation of the NMDAR, by activation of the glycine-binding site, may compensate relational memory impairments due to hippocampal muscarinic neurotransmission dysfunction possibly through enhancements in LTP maintenance. PMID:25453488

Portero-Tresserra, Marta; Del Olmo, Nuria; Martí-Nicolovius, Margarita; Guillazo-Blanch, Gemma; Vale-Martínez, Anna

2014-11-01

202

One-trial conditioned taste aversion in Lymnaea: good and poor performers in long-term memory acquisition.  

Science.gov (United States)

In the majority of studies designed to elucidate the causal mechanisms of memory formation, certain members of the experimental cohort, even though subjected to exactly the same conditioning procedures, remember significantly better than others, whereas others show little or no long-term memory (LTM) formation. To begin to address the question of why this phenomenon occurs and thereby help clarify the causal mechanism of LTM formation, we used a conditioned taste aversion (CTA) procedure on individuals of the pond snail Lymnaea stagnalis and analyzed their subsequent behavior. Using sucrose as an appetitive stimulus and KCl as an aversive stimulus, we obtained a constant ratio of ;poor' to ;good' performers for CTA-LTM. We found that approximately 40% of trained snails possessed LTM following a one-trial conditioning procedure. When we examined the time-window necessary for the memory consolidation, we found that if we cooled snails to 4 degrees C for 30 min within 10 min after the one-trial conditioning, LTM was blocked. However, with delayed cooling (i.e. longer than 10 min), LTM was present. We could further interfere with LTM formation by inducing inhibitory learning (i.e. backward conditioning) after the one-trial conditioning. Finally, we examined whether we could motivate snails to acquire LTM by depriving them of food for 5 days before the one-trial conditioning. Food-deprived snails, however, failed to exhibit LTM following the one-trial conditioning. These results will help us begin to clarify why some individuals are better at learning and forming memory for specific tasks at the neuronal level. PMID:17371921

Sugai, Rio; Azami, Sachiyo; Shiga, Hatsuki; Watanabe, Takayuki; Sadamoto, Hisayo; Kobayashi, Suguru; Hatakeyama, Dai; Fujito, Yutaka; Lukowiak, Ken; Ito, Etsuro

2007-04-01

203

Monosynaptic connections made by the sensory neurons of the gill- and siphon-withdrawal reflex in Aplysia participate in the storage of long-term memory for sensitization  

OpenAIRE

We have found that in the gill- and siphon- withdrawal reflex of Aplysia, the memory for short-term sensitization grades smoothly into long-term memory with increased amounts of sensitization training. One cellular locus for the storage of the memory underlying short-term sensitization is the set of monosynaptic connections between the siphon sensory cells and the gill and siphon motor neurons. We have now also found that these same monosynaptic connections participate in the storage of the m...

Frost, William N.; Castellucci, Vincent F.; Hawkins, Robert D.; Kandel, Eric R.

1985-01-01

204

Molecular Mechanisms Underlying Formation of Long-Term Reward Memories and Extinction Memories in the Honeybee ("Apis Mellifera")  

Science.gov (United States)

The honeybee ("Apis mellifera") has long served as an invertebrate model organism for reward learning and memory research. Its capacity for learning and memory formation is rooted in the ecological need to efficiently collect nectar and pollen during summer to ensure survival of the hive during winter. Foraging bees learn to associate a…

Eisenhardt, Dorothea

2014-01-01

205

Hearing Loss Is Negatively Related to Episodic and Semantic Long-Term Memory but Not to Short-Term Memory  

Science.gov (United States)

Purpose: To test the relationship between degree of hearing loss and different memory systems in hearing aid users. Method: Structural equation modeling (SEM) was used to study the relationship between auditory and visual acuity and different cognitive and memory functions in an age-hetereogenous subsample of 160 hearing aid users without…

Ronnberg, Jerker; Danielsson, Henrik; Rudner, Mary; Arlinger, Stig; Sternang, Ola; Wahlin, Ake; Nilsson, Lars-Goran

2011-01-01

206

Episodic Long-Term Memory of Spoken Discourse Masked by Speech: What Is the Role for Working Memory Capacity?  

Science.gov (United States)

Purpose: To investigate whether working memory capacity (WMC) modulates the effects of to-be-ignored speech on the memory of materials conveyed by to-be-attended speech. Method: Two tasks (reading span, Daneman & Carpenter, 1980; Ronnberg et al., 2008; and size-comparison span, Sorqvist, Ljungberg, & Ljung, 2010) were used to measure individual…

Sorqvist, Patrik; Ronnberg, Jerker

2012-01-01

207

Spatio-temporal in vivo recording of dCREB2 dynamics in Drosophila long-term memory processing.  

Science.gov (United States)

CREB (cAMP response element-binding protein) is an evolutionarily conserved transcription factor, playing key roles in synaptic plasticity, intrinsic excitability and long-term memory (LTM) formation. The Drosophila homologue of mammalian CREB, dCREB2, is also important for LTM. However, the spatio-temporal nature of dCREB2 activity during memory consolidation is poorly understood. Using an in vivo reporter system, we examined dCREB2 activity continuously in specific brain regions during LTM processing. Two brain regions that have been shown to be important for Drosophila LTM are the ellipsoid body (EB) and the mushroom body (MB). We found that dCREB2 reporter activity is persistently elevated in EB R2/R4m neurons, but not neighboring R3/R4d neurons, following LTM-inducing training. In multiple subsets of MB neurons, dCREB2 reporter activity is suppressed immediately following LTM-specific training, and elevated during late windows. In addition, we observed heterogeneous responses across different subsets of neurons in MB ?? lobe during LTM processing. All of these changes suggest that dCREB2 functions in both the EB and MB for LTM formation, and that this activity contributes to the process of systems consolidation. PMID:25460038

Zhang, Jiabin; Tanenhaus, Anne K; Davis, John C; Hanlon, Bret M; Yin, Jerry C P

2015-02-01

208

A novel role for extracellular signal-regulated kinase in maintaining long-term memory-relevant excitability changes.  

Science.gov (United States)

Pyramidal neurons in the piriform cortex from olfactory-discrimination-trained rats show enhanced intrinsic neuronal excitability that lasts for several days after learning. Such enhanced intrinsic excitability is mediated by long-term reduction in the postburst afterhyperpolarization (AHP), which is generated by repetitive spike firing. AHP reduction is attributable to decreased conductance of a calcium-dependent potassium current, the sI(AHP). We have previously shown that such learning-induced AHP reduction is maintained by PKC activation. However, the molecular machinery underlying such long-lasting modulation of intrinsic excitability is yet to be fully described. Here we examine whether the extracellular signal-regulated kinase I/II (ERKI/II) pathway, which is known to be crucial in learning, memory, and synaptic plasticity processes, is instrumental for the long-term maintenance of learning-induced AHP reduction. PD98059 or UO126, which selectively block MEK, the upstream kinase of ERK, increased the AHP in neurons from trained rats but not in neurons from naive and pseudo-trained rats. Consequently, the differences in AHP amplitude and neuronal adaptation between neurons from trained rats and controls were abolished. This effect was not mediated by modulation of basic membrane properties. In accordance with its effect on neuronal excitability, the level of activated ERK in the membranal fraction was significantly higher in piriform cortex samples taken from trained rats. In addition, the PKC activator OAG (1-oleoyl-20acety-sn-glycerol), which was shown to reduce the AHP in neurons from control rats, had no effect on these neurons in the presence of PD98059. Our data show that ERK has a key role in maintaining long-lasting learning-induced enhancement of neuronal excitability. PMID:18003837

Cohen-Matsliah, Sivan Ida; Brosh, Inbar; Rosenblum, Kobi; Barkai, Edi

2007-11-14

209

Rolipram, a type IV-specific phosphodiesterase inhibitor, facilitates the establishment of long-lasting long-term potentiation and improves memory  

OpenAIRE

In an attempt to improve behavioral memory, we devised a strategy to amplify the signal-to-noise ratio of the cAMP pathway, which plays a central role in hippocampal synaptic plasticity and behavioral memory. Multiple high-frequency trains of electrical stimulation induce long-lasting long-term potentiation, a form of synaptic strengthening in hippocampus that is greater in both magnitude and persistence than the short-lasting long-term potentiation generated by a single tetanic train. Studie...

Barad, Mark; Bourtchouladze, Roussoudan; Winder, Danny G.; Golan, Hava; Kandel, Eric

1998-01-01

210

Long-term potentiation and memory processes in the psychological works of Sigmund Freud and in the formation of neuropsychiatric symptoms.  

Science.gov (United States)

Far from disproving the model of mind functioning proposed by psychoanalysis, the recent advances in neuropsychiatrical research confirmed the crucial ideas of Sigmund Freud. The hypothesis that the origin of mental illnesses lies in the impossibility for a subject to erase the long-term effects of a remote adverse event is in tune with the view that several psychiatric disturbances reflect the activation of aberrant unconscious memory processes. Freud's insights did not stop here, but went on to describe in an extremely precise manner the neural mechanisms of memory formation almost a century before the description of long-term synaptic potentiation. PMID:15590140

Centonze, D; Siracusano, A; Calabresi, P; Bernardi, G

2005-01-01

211

Understanding the neurobiological mechanisms of learning and memory: Memory systems of the brain, long term potentiation and synaptic...  

Directory of Open Access Journals (Sweden)

Full Text Available El fenómeno de LTP es una forma de plasticidad sináptica ampliamente aceptado como un modelo de estabilización de sinapsis en procesos neurobiológicos como el desarrollo del SNC y el fenómeno de aprendizaje y memoria. Desde su descubrimiento por Bliss y Lomo (1973, el fenómeno de potenciación a largo plazo (PLP o LTP (Long-Term Potentiation, por sus siglas en inglés ha sido definido convencionalmente como la estimulación aferente de alta frecuencia que es capaz de despolarizar la célula postsináptica, a través de la activación de receptores glutamaérgicos, con la resultante entrada de calcio a la neurona postsináptica. Este evento neurobiológico produce un incremento intracelular en la concentración de calcio [(Cai] que induce la activación de diferentes sistemas moleculares de señalamiento intracelular (AMPc, proteínas cinasas, fosforilación de proteínas intracelulares que conlleva a una alteración de la actividad postsináptica y/o presináptica, dando por resultado un persistente incremento de respuesta sináptica específica dependiente de la activación del receptor glutamaérgico NMDA...

Philippe Leff

2002-01-01

212

CREB Antisense Oligodeoxynucleotide Administration into the Dorsal Hippocampal CA3 Region Impairs Long- but Not Short-Term Spatial Memory in Mice  

Science.gov (United States)

The transcription factor cAMP response-element binding protein (CREB) has a pivotal role in hippocampal synaptic plasticity and hippocampus-dependent long-term memory. We recently demonstrated that the dorsal hippocampal CA3 region is involved in memory consolidation of spatial information tested on a Morris water maze in mice. To test whether…

Florian, Cedrick; Mons, Nicole; Roullet, Pascal

2006-01-01

213

Long-term memory traces for language sounds are highly context-sensitive: an MEG/ERF study  

DEFF Research Database (Denmark)

Introduction: An early component of the auditory event-related potential (ERP), the mismatch negativity (MMN), has been shown to be sensitive to native phonemic language sound contrasts compared to non-native or allophonic language sound contrasts. So far this has not been attested for different phonetic contexts. In the present study we investigated the mismatch field (MMF) response (the magnetic counterpart of the MMN) of native Danish speakers to the Danish phonetic contrast of [t]-[d] in two different phonetic contexts: One in which the sound contrast was phonemic ([tæ] versus [dæ]), and one in which the sound contrast was allophonic ([æt] versus [æd]), i.e. its phonemic status was neutralized. Methods: The stimuli consisted of the four Danish syllables: [tæ] and [dæ] (meaning ‘take’ and ‘then’, respectively), and [æt] and [æd] (both meaning ‘that’). These were presented in a passive listening MMN paradigm while participants’ MEG was recorded. [tæ] and [æt] acted as standards, and [dæ] and [æd] thus as deviants, respectively. Results: Comparing brain responses to the deviants and the standards, only the phonemic [tæ]-[dæ] contrast showed significant effects (FWE-corrected at p<0.05 at the cluster-level) within the typical MMN time range (100 to 300 ms after deviance onset) and over both hemispheres. Comparing the differences between the two contrasts ([dæ]-[tæ] minus [æd]-[æt]), the phonemic context elicited significantly larger MMF responses than the allophonic context (FWE-corrected at p<0.05 at the cluster-level), again over both hemispheres and within the typical MMN time range. Conclusion: By manipulating the immediate phonetic context in an oddball paradigm, we demonstrate that the human brain’s MMF response to language sounds is highly context-sensitive. This has important impact on the proposed long-term memory traces for native phonological categories. In order to generate different MMF responses to the same language sound contrast depending on the phonetic context, these long-term memory traces must thus be context-sensitive themselves or exist as separate traces for the context-dependent allophones of the phonological categories.

Nielsen, Andreas HØjlund; Gebauer, Line

214

[The influence of long-term memory on visuo-spatial sketchpad: a test of a new factor causing recency effects].  

Science.gov (United States)

Three immediate serial recall experiments, using articulatory suppression examined the influence of visual long-term memory on visuo-spatial sketchpad. In Experiments 1 and 2, serial recall rates of unfamiliar figures, familiar figures, and numbers were investigated. The results showed that the more visual long-term memory the stimuli evoked, the more salient recency effects and primacy effects occurred. Based on these results, the following process is hypothesized to be one of the factors causing recency effects. If the visual information of items inputted into visuo-spatial sketchpad is already in long-term memory, only their retrieval cues are formed and retained. Thus, other information is erased from visuo-spatial sketchpad, which makes more room, so that subsequent items are inputted into visuo-spatial sketchpad. In Experiment 3, reaction times of a visual secondary task during presentation were measured. The results indicated that there was more room in visuo-spatial sketchpad when primacy and recency effects occurred, which supported the hypothesis. Finally, the interaction of working memory and long-term memory is discussed. PMID:9121008

Mizuno, R

1996-12-01

215

The Effects of Intersensory Redundancy on Attention and Memory: Infants' Long-Term Memory for Orientation in Audiovisual Events  

Science.gov (United States)

This research examined the effects of bimodal audiovisual and unimodal visual stimulation on infants' memory for the visual orientation of a moving toy hammer following a 5-min, 2-week, or 1-month retention interval. According to the intersensory redundancy hypothesis (L. E. Bahrick & R. Lickliter, 2000; L. E. Bahrick, R. Lickliter, & R. Flom,…

Flom, Ross; Bahrick, Lorraine E.

2010-01-01

216

Vividness of visual imagery and incidental recall of verbal cues, when phenomenological availability reflects long-term memory accessibility  

Directory of Open Access Journals (Sweden)

Full Text Available The relationship between vivid visual mental images and unexpected recall (incidental recall was replicated, refined and extended. In Experiment 1, participants were asked to generate mental images from imagery-evoking verbal-cues (controlled on several verbal properties and then, on a trial-by-trial basis, rate the vividness of their images; thirty minutes later, participants were surprised with a task requiring free recall of the cues. Higher vividness ratings predicted better incidental recall of the cues than individual differences (whose effect was modest. Distributional analysis of image latencies through ex-Gaussian modeling showed an inverse relation between vividness and latency. However, recall was unrelated to image latency. The follow-up Experiment 2 showed that the processes underlying trial-by-trial vividness ratings are unrelated to the Vividness of Visual Imagery Questionnaire (VVIQ, as further supported by a meta-analysis of a randomly selected sample of relevant literature. The present findings suggest that vividness may act as an index of availability of long-term sensory traces, playing a non-epiphenomenal role in facilitating the access of those memories.

AmedeoD'Angiulli

2013-02-01

217

X11beta rescues memory and long-term potentiation deficits in Alzheimer's disease APPswe Tg2576 mice.  

LENUS (Irish Health Repository)

Increased production and deposition of amyloid beta-protein (Abeta) are believed to be key pathogenic events in Alzheimer\\'s disease. As such, routes for lowering cerebral Abeta levels represent potential therapeutic targets for Alzheimer\\'s disease. X11beta is a neuronal adaptor protein that binds to the intracellular domain of the amyloid precursor protein (APP). Overexpression of X11beta inhibits Abeta production in a number of experimental systems. However, whether these changes to APP processing and Abeta production induced by X11beta overexpression also induce beneficial effects to memory and synaptic plasticity are not known. We report here that X11beta-mediated reduction in cerebral Abeta is associated with normalization of both cognition and in vivo long-term potentiation in aged APPswe Tg2576 transgenic mice that model the amyloid pathology of Alzheimer\\'s disease. Overexpression of X11beta itself has no detectable adverse effects upon mouse behaviour. These findings support the notion that modulation of X11beta function represents a therapeutic target for Abeta-mediated neuronal dysfunction in Alzheimer\\'s disease.

Mitchell, Jacqueline C

2009-12-01

218

Making the Case that Episodic Recollection is Attributable to Operations Occurring at Retrieval rather than to Content Stored in a Dedicated Subsystem of Long-Term Memory  

Directory of Open Access Journals (Sweden)

Full Text Available Episodic memory often is conceptualized as a uniquely human system of long-term memory that makes available knowledge accompanied by the temporal and spatial context in which that knowledge was acquired. Retrieval from episodic memory entails a form of first–person subjectivity called autonoetic consciousness that provides a sense that a recollection was something that took place in the experiencer’s personal past. In this paper I expand on this definition of episodic memory. Specifically, I suggest that (a the core features assumed unique to episodic memory are shared by semantic memory, (b episodic memory cannot be fully understood unless one appreciates that episodic recollection requires the coordinated function of a number of distinct, yet interacting, “enabling” systems. Although these systems – ownership, self, subjective temporality, and agency – are not traditionally viewed as memorial in nature, each is necessary for episodic recollection and jointly they may be sufficient, and (c the type of subjective awareness provided by episodic recollection (autonoetic is relational rather than intrinsic – i.e., it can be lost in certain patient populations, thus rendering episodic memory content indistinguishable from the content of semantic long-term memory.

StanKlein

2013-02-01

219

Improvement in Memory and Brain Long-term Potentiation Deficits Due to Permanent Hypoperfusion/Ischemia by Grape Seed Extract in Rats  

OpenAIRE

Objective(s): Cerebral hypoperfusion/ischemia (CHI) is a neurological disease where impaired hippocampus electrical activity and cognition caused by a serial pathophysiological events. This study aimed to evaluate the effects of chronic oral administration of grape seed extract (GSE) on passive avoidance memory and long-term potentiation (LTP) after permanent bilateral common carotid arteries occlusion (2CCAO) in male adult rats.

Sarkaki, Alireza; Rafieirad, Maryam; Hossini, Seyed Ebrahim; Farbood, Yaghoub; Motamedi, Fereshteh; Mansouri, Seyed Mohammad Taghi; Naghizadeh, Bahareh

2013-01-01

220

The hippocampus supports high-resolution binding in the service of perception, working memory and long-term memory.  

Science.gov (United States)

It is well established that the hippocampus plays a critical role in our ability to recollect past events. A number of recent studies have indicated that the hippocampus may also play a critical role in working memory and perception, but these results have been highly controversial because other similar studies have failed to find evidence for hippocampal involvement. Thus, the precise role that the hippocampus plays in cognition is still debated. In the current paper, I propose that the hippocampus supports the generation and utilization of complex high-resolution bindings that link together the qualitative aspects that make up an event; these bindings are essential for recollection, and they can also contribute to performance across a variety of tasks including perception and working memory. An examination of the existing patient literature provides support for this proposal by showing that hippocampal damage leads to impairments on perception and working memory tasks that require complex high-resolution bindings. Conversely, hippocampal damage is much less likely to lead to impairments on tasks that require only low-resolution or simple associations/relations. The current proposal can be distinguished from earlier accounts of hippocampal function, and it generates a number of novel predictions that can be tested in future studies. PMID:23721964

Yonelinas, Andrew P

2013-10-01

221

The E3 Ligase APC/C-Cdh1 Is Required for Associative Fear Memory and Long-Term Potentiation in the Amygdala of Adult Mice  

Science.gov (United States)

The anaphase promoting complex/cyclosome (APC/C) is an E3 ligase regulated by Cdh1. Beyond its role in controlling cell cycle progression, APC/C-Cdh1 has been detected in neurons and plays a role in long-lasting synaptic plasticity and long-term memory. Herein, we further examined the role of Cdh1 in synaptic plasticity and memory by generating…

Pick, Joseph E.; Malumbres, Marcos; Klann, Eric

2013-01-01

222

PKA Increases in the Olfactory Bulb Act as Unconditioned Stimuli and Provide Evidence for Parallel Memory Systems: Pairing Odor with Increased PKA Creates Intermediate- and Long-Term, but Not Short-Term, Memories  

Science.gov (United States)

Neonatal odor-preference memory in rat pups is a well-defined associative mammalian memory model dependent on cAMP. Previous work from this laboratory demonstrates three phases of neonatal odor-preference memory: short-term (translation-independent), intermediate-term (translation-dependent), and long-term (transcription- and…

Grimes, Matthew T.; Harley, Carolyn W.; Darby-King, Andrea; McLean, John H.

2012-01-01

223

Beyond Initial Encoding: Measures of the Post-Encoding Status of Memory Traces Predict Long-Term Recall during Infancy  

Science.gov (United States)

The first years of life are witness to rapid changes in long-term recall ability. In the current research we contributed to an explanation of the changes by testing the absolute and relative contributions to long-term recall of encoding and post-encoding processes. Using elicited imitation, we sampled the status of 16-, 20-, and 24-month-old…

Pathman, Thanujeni; Bauer, Patricia J.

2013-01-01

224

Long-term memory-based control of attention in multi-step tasks requires working memory: evidence from domain-specific interference  

Science.gov (United States)

Evidence for long-term memory (LTM)-based control of attention has been found during the execution of highly practiced multi-step tasks. However, does LTM directly control for attention or are working memory (WM) processes involved? In the present study, this question was investigated with a dual-task paradigm. Participants executed either a highly practiced visuospatial sensorimotor task (speed stacking) or a verbal task (high-speed poem reciting), while maintaining visuospatial or verbal information in WM. Results revealed unidirectional and domain-specific interference. Neither speed stacking nor high-speed poem reciting was influenced by WM retention. Stacking disrupted the retention of visuospatial locations, but did not modify memory performance of verbal material (letters). Reciting reduced the retention of verbal material substantially whereas it affected the memory performance of visuospatial locations to a smaller degree. We suggest that the selection of task-relevant information from LTM for the execution of overlearned multi-step tasks recruits domain-specific WM. PMID:24847304

Foerster, Rebecca M.; Carbone, Elena; Schneider, Werner X.

2014-01-01

225

The effect of frequency and duration of training sessions on acquisition and long-term memory in dogs  

DEFF Research Database (Denmark)

Most domestic dogs are subjected to some kind of obedience training, often on a frequent basis, but the question of how often and for how long a dog should be trained has not been fully investigated. Optimizing the training as much as possible is not only an advantage in the training of working dogs such as guide dogs and police dogs, also the training of family dogs can benefit from this knowledge. We studied the effect of frequency and duration of training sessions on acquisition and on long-term memory. Forty-four laboratory Beagles were divided into 4 groups and trained by means of operant conditioning and shaping to perform a traditional obedience task, each dog having a total of 18 training sessions. The training schedules of the 4 groups differentiated in frequency (1–2 times per week vs. daily) and duration (1 training session vs. 3 training sessions in a row). Acquisition was measured as achieved training level at a certain time. The dogs’ retention of the task was tested four weeks post-acquisition.Results demonstrated that dogs trained 1–2 times per week had significantly better acquisition than daily trained dogs, and that dogs trained only 1 session a day had significantly better acquisition than dogs trained 3 sessions in a row. The interaction between frequency and duration of training sessions was also significant, suggesting that the two affect acquisition differently depending on the combination of these. The combination of weekly training and one session resulted in the highest level of acquisition, whereas the combination of daily training and three sessions in a row resulted in the lowest level of acquisition. Daily training in one session produced similar results as weekly training combined with three sessions in a row. Training schedule did not affect retention of the learned task; all groups had a high level of retention after 4 weeks. The results of the study can be used to optimize training in dogs, which is important since the number of training sessions often is a limiting factor in practical dog training. The results also suggest that, once a task is learned, it is likely to be remembered for a period of at least four weeks after last practice, regardless of frequency and duration of the training sessions.

Demant, Helle; Ladewig, Jan

2011-01-01

226

Critical Role of Nitric Oxide-cGMP Cascade in the Formation of cAMP-Dependent Long-Term Memory  

Science.gov (United States)

Cyclic AMP pathway plays an essential role in formation of long-term memory (LTM). In some species, the nitric oxide (NO)-cyclic GMP pathway has been found to act in parallel and complementary to the cAMP pathway for LTM formation. Here we describe a new role of the NO-cGMP pathway, namely, stimulation of the cAMP pathway to induce LTM. We have…

Aonuma, Hitoshi; Mizunami, Makoto; Matsumoto, Yukihisa; Unoki, Sae

2006-01-01

227

Medial prefrontal cortex dopamine controls the persistent storage of aversive memories  

OpenAIRE

Medial prefrontal cortex (mPFC) is essential for initial memory processing and expression but its involvement in persistent memory storage has seldom been studied. Using the hippocampus dependent inhibitory avoidance learning task and the hippocampus-independent conditioned taste aversion paradigm together with specific dopamine receptor agonists and antagonists we found that persistence but not formation of long-term aversive memories requires dopamine D1/D5 receptors activation in mPFC imme...

Gonzalez, Mari?a C.; Kramar, Cecilia P.; Tomaiuolo, Micol; Katche, Cynthia; Weisstaub, Noelia; Cammarota, Marti?n; Medina, Jorge H.

2014-01-01

228

Cyclic Nucleotide-Gated Channels, Calmodulin, Adenylyl Cyclase, and Calcium/Calmodulin-Dependent Protein Kinase II Are Required for Late, but Not Early, Long-Term Memory Formation in the Honeybee  

Science.gov (United States)

Memory is a dynamic process that allows encoding, storage, and retrieval of information acquired through individual experience. In the honeybee "Apis mellifera," olfactory conditioning of the proboscis extension response (PER) has shown that besides short-term memory (STM) and mid-term memory (MTM), two phases of long-term memory (LTM)…

Matsumoto, Yukihisa; Sandoz, Jean-Christophe; Devaud, Jean-Marc; Lormant, Flore; Mizunami, Makoto; Giurfa, Martin

2014-01-01

229

Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC) affects differently working and long-term memory on two foraging tasks  

Scientific Electronic Library Online (English)

Full Text Available Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay stra [...] tegy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC) was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable

PABLO, ESPINA-MARCHANT; TERESA, PINTO-HAMUY; DIEGO, BUSTAMANTE; PAOLA, MORALES; LUIS, ROBLES; MARIO, HERRERA-MARSCHITZ.

230

Spatial cognition and memory: a reversible lesion with lidocaine into the anteromedial/posterior parietal cortex (AM/PPC affects differently working and long-term memory on two foraging tasks  

Directory of Open Access Journals (Sweden)

Full Text Available Place memory is relevant for exploration and forage behaviour. When food supply is dispersed, a win-shift has advantage over a win-stay strategy. In the Olton Octagonal Maze, the rat follows a win-shift strategy using working memory. However, in the Olton 4x4 version, the rat follows a win-stay strategy, using both working and long-term memories. It has been suggested that the neocortex is required for the resolution of tasks demanding long-term, but not for that demanding working memory alone. The role of anteromedial/posterior parietal cortex (AM/PPC was investigated here, using a reversible lesion induced by intracerebral lidocaine infusion. Long-Evans rats were implanted with guide cannulae into the AM/PPC and trained in an Olton 4x4 maze, counting working and long-term memory errors after a delay. Then, the animals were infused with lidocaine or saline during the delay phase and tested for three days. Another series of animals, treated as before, was tested in an Olton Octagonal Maze and subjected to the same injection schedule. In the Olton 4x4 Maze, lidocaine produced a significant increase in working and long-term memory errors, compared to saline and post-lidocaine conditions. In contrast, in the Olton Octagonal Maze, lidocaine did not induce any effect on working memory errors. Thus, AM/PPC is required when both working with previous information and long-term memories are needed, but not when only working memory is required, as it happens under ethological conditions. Whenever food supply is dispersed, a win-shift strategy is preferable

PABLO ESPINA-MARCHANT

2006-01-01

231

Extracellular Signal-Regulated Kinase Activity in the Entorhinal Cortex Is Necessary for Long-Term Spatial Memory  

OpenAIRE

Lesion studies have provided evidence that the entorhinal cortex (EC) participates in spatial memory. However, the molecular cascades that underlie memory-associated changes in the EC and its specific role in spatial memory, however, have not been clearly delineated. Recently, it has been shown that activation of extracellular signal-regulated kinase (Erk, a mitogen-activated protein kinase family member) in the dorsal hippocampus is necessary for spatial memory. To examine whether similar me...

Hebert, April E.; Dash, Pramod K.

2002-01-01

232

Maternal Diabetes in Pregnancy: Early and Long-Term Outcomes on the Offspring and the Concept of “Metabolic Memory  

OpenAIRE

The adverse outcomes on the offspring from maternal diabetes in pregnancy are substantially documented. In this paper, we report main knowledge on impacts of maternal diabetes on early and long-term health of the offspring, with specific comments on maternal obesity. The main adverse outcome on progenies from pregnancy complicated with maternal diabetes appears to be macrosomia, as it is commonly known that intrauterine exposure to hyperglycemia increases the risk and programs the offspring t...

Yessoufou, Akadiri; Moutairou, Kabirou

2011-01-01

233

Long-term memory in Aplysia modulates the total number of varicosities of single identified sensory neurons.  

OpenAIRE

The morphological consequences of long-term habituation and sensitization of the gill withdrawal reflex in Aplysia california were explored by examining the total number of presynaptic varicosities of single identified sensory neurons (a critical site of plasticity for the biochemical and biophysical changes that underlie both types of learning) in control and behaviorally trained animals. Sensory neurons from habituated animals had 35% fewer synaptic varicosities than did sensory neurons fro...

Bailey, C. H.; Chen, M.

1988-01-01

234

Improvement in Memory and Brain Long-term Potentiation Deficits Due to Permanent Hypoperfusion/Ischemia by Grape Seed Extract in Rats  

Directory of Open Access Journals (Sweden)

Full Text Available   Objective(s: Cerebral hypoperfusion/ischemia (CHI is a neurological disease where impaired hippocampus electrical activity and cognition caused by a serial pathophysiological events. This study aimed to evaluate the effects of chronic oral administration of grape seed extract (GSE on passive avoidance memory and long-term potentiation (LTP after permanent bilateral common carotid arteries occlusion (2CCAO in male adult rats.   Materials and Methods: Thirty-two adult male Wistar rats were randomly divided into: 1 Sham+Veh, 2 Isch+Veh, 3 Sham+GSE, 4 Isch+GSE. In order to make 2CCAO as an animal model of CHI, carotid arteries were ligatured and then cut bilaterally. To evaluation of passive avoidance memory, step-down latency (STL was measured and LTP was recorded from hippocampal dentate gyrus (DG after high frequency stimulation (HFS in all rats. Results: We found that memory was significantly impaired in rats after CHI (P

Alireza Sarkaki

2013-09-01

235

Olfaction, Emotion, and the Amygdala: arousal-dependent modulation of long-term autobiographical memory and its association with olfaction: beginning to unravel the Proust phenomenon?  

Directory of Open Access Journals (Sweden)

Full Text Available The sense of smell is set apart from other sensory modalities. Odours possess the capacity to trigger immediately strong emotional memories. Moreover, odorous stimuli provide a higher degree of memory retention than other sensory stimuli. Odour perception, even in its most elemental form - olfaction - already involves limbic structures. This early involvement is not paralleled in other sensory modalities. Bearing in mind the considerable connectivity with limbic structures, and the fact that an activation of the amygdala is capable of instantaneously evoking emotions and facilitating the encoding of memories, it is unsurprising that the sense of smell has its characteristic nature. The aim of this review is to analyse current understanding of higher olfactory information processing as it relates to the ability of odours to spontaneously cue highly vivid, affectively toned, and often very old autobiographical memories (episodes known anecdotally as Proust phenomena. Particular emphasis is placed on the diversity of functions attributed to the amygdala. Its role in modulating the encoding and retrieval of long-term memory is investigated with reference to lesion, electrophysiological, immediate early gene, and functional imaging studies in both rodents and humans. Additionally, the influence of hormonal modulation and the adrenergic system on emotional memory storage is outlined. I finish by proposing a schematic of some of the critical neural pathways that underlie the odour-associated encoding and retrieval of emotionally toned autobiographical memories.

Mark Hughes

2004-06-01

236

Preservation of vaccine-induced long-term B cell memory and the effects of immunosuppressive treatment  

OpenAIRE

Immune memory after vaccination is largely dependent on the combination of antibody production from long-lived plasma cells, and a supporting pool of antigen-primed memory B cells. It has been observed that individuals with certain immunosuppressive conditions or treatments have a weakened B cell memory, but the mechanisms behind remain elusive. The aim of this thesis was to evaluate B cell immunity in healthy children, and how HIV-1 infection, antineoplastic therapy, and rheum...

Ingelman-sundberg, Hanna M.

2015-01-01

237

Zif268/Egr1 gain of function facilitates hippocampal synaptic plasticity and long-term spatial recognition memory  

OpenAIRE

It is well established that Zif268/Egr1, a member of the Egr family of transcription factors, is critical for the consolidation of several forms of memory; however, it is as yet uncertain whether increasing expression of Zif268 in neurons can facilitate memory formation. Here, we used an inducible transgenic mouse model to specifically induce Zif268 overexpression in forebrain neurons and examined the effect on recognition memory and hippocampal synaptic transmission and plasticity. We found ...

Penke, Zsuzsa; Morice, Elise; Veyrac, Alexandra; Gros, Alexandra; Chagneau, Carine; Leblanc, Pascale; Samson, Nathalie; Baumga?rtel, Karsten; Mansuy, Isabelle M.; Davis, Sabrina; Laroche, Serge

2014-01-01

238

Enhancement of memory-related long-term facilitation by ApAF, a novel transcription factor that acts downstream from both CREB1 and CREB2.  

OpenAIRE

The memory for sensitization of the gill withdrawal reflex in Aplysia is reflected in facilitation of the monosynaptic connection between the sensory and motor neurons of the reflex. The switch from short- to long-term facilitation requires activation of CREB1, derepression of ApCREB2, and induction of ApC/EBP. In search for genes that act downstream from CREB1, we have identified a transcription activator, ApAF, which is stimulated by protein kinase A and can dimerize with both ApC/EBP and A...

Ghirardi, Mirella; Giustetto, Maurizio

2000-01-01

239

CREB antisense oligodeoxynucleotide administration into the dorsal hippocampal CA3 region impairs long- but not short-term spatial memory in mice  

OpenAIRE

The transcription factor cAMP response-element binding protein (CREB) has a pivotal role in hippocampal synaptic plasticity and hippocampus-dependent long-term memory. We recently demonstrated that the dorsal hippocampal CA3 region is involved in memory consolidation of spatial information tested on a Morris water maze in mice. To test whether activation of CREB in the CA3 region is required for memory consolidation of spatial information, bilaterally cannulated mice were infused 18 h before ...

Florian, Ce?drick; Mons, Nicole; Roullet, Pascal

2006-01-01

240

Newcastle disease virotherapy induces long-term survival and tumor-specific immune memory in orthotopic glioma through the induction of immunogenic cell death.  

Science.gov (United States)

The oncolytic features of several naturally oncolytic viruses have been shown on Glioblastoma Multiforme cell lines and in xenotransplant models. However, orthotopic glioma studies in immunocompetent animals are lacking. Here we investigated Newcastle disease virus (NDV) in the orthotopic, syngeneic murine GL261 model. Seven days after tumor induction, mice received NDV intratumorally. Treatment significantly prolonged median survival and 50% of animals showed long-term survival. We demonstrated immunogenic cell death (ICD) induction in GL261 cells after NDV infection, comprising calreticulin surface exposure, release of HMGB1 and increased PMEL17 cancer antigen expression. Uniquely, we found absence of secreted ATP. NDV-induced ICD occurred independently of caspase signaling and was blocked by Necrostatin-1, suggesting the contribution of necroptosis. Autophagy induction following NDV infection of GL261 cells was demonstrated as well. In vivo, elevated infiltration of IFN-?(+) T cells was observed in NDV-treated tumors, along with reduced accumulation of myeloid derived suppressor cells. The importance of a functional adaptive immune system in this paradigm was demonstrated in immunodeficient Rag2(-/-) mice and in CD8(+) T cell depleted animals, where NDV slightly prolonged survival, but failed to induce long-term cure. Secondary tumor induction with GL261 cells or LLC cells in mice surviving long-term after NDV treatment, demonstrated the induction of a long-term, tumor-specific immunological memory response by ND virotherapy. For the first time, we describe the therapeutic activity of NDV against GL261 tumors, evidenced in an orthotopic mouse model. The therapeutic effect relies on the induction of ICD in the tumor cells, which primes adaptive antitumor immunity. PMID:25208916

Koks, Carolien A; Garg, Abhishek D; Ehrhardt, Michael; Riva, Matteo; Vandenberk, Lien; Boon, Louis; De Vleeschouwer, Steven; Agostinis, Patrizia; Graf, Norbert; Van Gool, Stefaan W

2015-03-01

241

Olfaction, Emtion & the Amygdala: arousal-dependent modulation of long-term autobiographical memory and its association with olfaction  

OpenAIRE

The sense of smell is set apart from other sensory modalities. Odours possess the capacity to trigger immediately strong emotional memories. Moreover, odorous stimuli provide a higher degree of memory retention than other sensory stimuli. Odour perception, even in its most elemental form - olfaction - already involves limbic structures. This early involvement is not paralleled in other sensory modalities. Bearing in mind the considerable connectivity with limbic structures, and the fact that ...

Mark Hughes

2004-01-01

242

The fundamental things apply... as time goes by : Students' long-term memories from an ecology field excursion  

OpenAIRE

The aim of this study was to investigate and analyse what biology students remembered a long time after being out on an ecology excursion. The students’ memories were tested during a stimulated recall interview and analysed using the dual memory system model of learning. Already after 6 months we found that the students had forgotten a lot of the scientific content. Very often they showed a familiarity (recognition) with the situations and objects showed to them but they were unable to iden...

Bjo?rklund, Lars; Stolpe, Karin

2013-01-01

243

Evidence for Hippocampus-Dependent Contextual Learning at Postnatal Day 17 in the Rat  

Science.gov (United States)

Long-term memory for fear of an environment (contextual fear conditioning) emerges later in development (postnatal day; PD 23) than long-term memory for fear of discrete stimuli (PD 17). As contextual, but not explicit cue, fear conditioning relies on the hippocampus; this has been interpreted as evidence that the hippocampus is not fully…

Foster, Jennifer A.; Burman, Michael A.

2010-01-01

244

Analysis of regulatory T-cells and of their naïve and memory-like subsets in long-term treated aviremic HIV+ patients and untreated viremic patients  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose of the study: Although HIV infection impacts the proportion and phenotype of regulatory T-cells (Tregs, discrepant results have been reported depending on the surface markers employed to characterize them and on the patient populations. In addition, the effects of a long-term combined antiretroviral therapy (cART on Treg cells have not been thoroughly documented. Our study investigated the frequency and number of Tregs and their phenotype in two different groups of HIV-infected patients: one aviremic undergoing long-term cART and one viremic naïve to cART showing a similar CD4+ cell count. Methods: Thirty-six HIV+ patients with sustained suppression of plasma viremia (<37 copies/mL on effective cART for more than 6 years and 22 HIV+patients naïve to cART and without clinical signs of opportunistic infections or tumors at the time of study (untreated group were included in the study. Healthy donors (HD were used as control. Flow cytometry on fresh whole blood was used to quantify total Tregs (defined as CD25+CD127low/-CD4+ cells and the following Treg subsets: naïve (CD45RA+CCR7+ Tregs, central-memory like Tregs (CD45RA-CCR7+, TregCM, effector-memory like Tregs (CD45RA-CCR7?, TregEM Statistical comparisons of the percentages and number of Tregs and Treg subpopulations were performed by ANOVA or Kruskal-Wallis test. Analysis of covariance was employed in order to adjust for the effect of the age. The Spearman's test was used to assess correlations. Summary of results: In viremic untreated and aviremic long-term cART-treated patients the percentage and number of the total Treg cells were not different from those of HD. However, the analysis of Treg phenotype showed a marked redistribution of the Treg subpopulations: in the untreated viremic patients, both the percentage and number of the TregCM subset decreased compared to HD and cART-treated patients, whereas only the percentage of naïve Tregs increased. In particular, the percentage of TregCM was inversely correlated with the viral load (r=?0.51; p=0.016. Conclusions: In our aviremic long-term cART-treated and viremic untreated patients, the total Treg cell population seems to be unaffected by HIV infection. However, our results showed that the analysis of the naïve and memory-like Treg subsets may provide a better understanding of the real contribution of Tregs in HIV disease and therapy.

L Imberti

2012-11-01

245

Analyses of fear memory in Arc/Arg3.1-deficient mice: intact short-term memory and impaired long-term and remote memory  

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Full Text Available Activity-regulated cytoskeleton-associated protein (Arc/Arg3.1 was originally identified in patients with seizures. It is densely distributed in the hip-pocampus and amygdala in particular. Because the expression of Arc/Arg3.1 is regulated by nerve in-puts, it is thought to be an immediate early gene. As shown both in vitro and in vivo, Arc/Arg3.1 is in-volved in synaptic consolidation and regulates some forms of learning and memory in rats and mice [1,2]. Furthermore, a recent study suggests that Arc/Arg3.1 may play a significant role in signal transmission via AMPA-type glutamate receptors [3-5]. Therefore, we conducted a detailed analysis of fear memory in Arc/Arg3.1-deficient mice. As previously reported, the knockout animals exhib-ited impaired fear memory in both contextual and cued test situations. Although Arc/Arg3.1-deficient mice showed almost the same performance as wild-type littermates 4 hr after a conditioning trial, their performance was impaired in the retention test after 24 hr or longer, either with or without reconsolidation. Immunohistochemical analyses showed an abnormal density of GluR1 in the hip-pocampus of Arc/Arg3.1-deficient mice; however, an application of AMPA potentiator did not improve memory performance in the mutant mice. Memory impairment in Arc/Arg3.1-deficient mice is so ro-bust that the mice provide a useful tool for devel-oping treatments for memory impairment.

Yoshiko Nagaoka

2011-05-01

246

Representational similarity analysis offers a preview of the noradrenergic modulation of long-term fear memory at the time of encoding.  

Science.gov (United States)

Neuroimaging research on emotional memory has greatly advanced our understanding of the pathogenesis of anxiety disorders. While the behavioral expression of fear at the time of encoding does not predict whether an aversive experience will evolve into long-term fear memory, the application of multi-voxel pattern analysis (MVPA) for the analysis of BOLD-MRI data has recently provided a unique marker for memory formation. Here, we aimed to further investigate the utility of this marker by modulating the strength of fear memory with an ?2-adrenoceptor antagonist (yohimbine HCl). Fifty-two healthy participants were randomly assigned to two conditions - either receiving 20mg yohimbine or a placebo pill (double-blind) - prior to differential fear conditioning and MRI-scanning. We examined the strength of fear associations during acquisition and retention of fear (48h later) by assessing the similarity of BOLD-MRI patterns and pupil dilation responses. Additionally, participants returned for a follow-up test outside the scanner (2-4 weeks), during which we assessed fear-potentiated startle responses. Replicating our previous findings, neural pattern similarity reflected the development of fear associations over time, and unlike average activation or pupil dilation, predicted the later expression of fear memory (pupil dilation 48h later). While no effect of yohimbine was observed on markers of autonomic arousal, including salivary ?-amylase (sAA), we obtained indirect evidence for the noradrenergic enhancement of fear memory consolidation: sAA levels showed a strong increase prior to fMRI scanning, irrespective of whether participants had received yohimbine, and this increase correlated with the subsequent expression of fear (48h later). Remarkably, this noradrenergic enhancement of fear was associated with changes in neural response patterns at the time of learning. These findings provide further evidence that representational similarity analysis is a sensitive tool for studying (enhanced) memory formation. PMID:25705798

Visser, Renée M; Kunze, Anna E; Westhoff, Bianca; Scholte, H Steven; Kindt, Merel

2015-05-01

247

Activin Plays a Key Role in the Maintenance of Long-Term Memory and Late-LTP  

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A recent study has revealed that fear memory may be vulnerable following retrieval, and is then reconsolidated in a protein synthesis-dependent manner. However, little is known about the molecular mechanisms of these processes. Activin [beta]A, a member of the TGF-[beta] superfamily, is increased in activated neuronal circuits and regulates…

Ageta, Hiroshi; Ikegami, Shiro; Miura, Masami; Masuda, Masao; Migishima, Rika; Hino, Toshiaki; Takashima, Noriko; Murayama, Akiko; Sugino, Hiromu; Setou, Mitsutoshi; Kida, Satoshi; Yokoyama, Minesuke; Hasegawa, Yoshihisa; Tsuchida, Kunihiro; Aosaki, Toshihiko; Inokuchi, Kaoru

2010-01-01

248

A long-term "memory" of HIF induction in response to chronic mild decreased oxygen after oxygen normalization  

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Full Text Available Abstract Background Endothelial dysfunction (ED is functionally characterized by decreased vasorelaxation, increased thrombosis, increased inflammation, and altered angiogenic potential, has been intimately associated with the progression and severity of cardiovascular disease. Patients with compromised cardiac function oftentimes have a state of chronic mild decreased oxygen at the level of the vasculature and organs, which has been shown to exacerbate ED. Hypoxia inducible factor (HIF is a transcription factor complex shown to be the master regulator of the cellular response to decreased oxygen levels and many HIF target genes have been shown to be associated with ED. Methods Human endothelial and aortic smooth muscle cells were exposed either to A normoxia (21% O2 for three weeks, or to B mild decreased oxygen (15% O2 for three weeks to mimic blood oxygen levels in patients with heart failure, or to C mild decreased oxygen for two weeks followed by one week of normoxia ("memory" treatment. Levels of HIF signaling genes (HIF-1?, HIF-2?, VEGF, BNIP3, GLUT-1, PAI-1 and iNOS were measured both at the protein and mRNA levels. Results It was found that chronic exposure to mild decreased oxygen resulted in significantly increased HIF signaling. There was also a "memory" of HIF-1? and HIF target gene induction when oxygen levels were normalized for one week, and this "memory" could be interrupted by adding a small molecule HIF inhibitor to the last week of normalized oxygen. Finally, levels of ubiquitylated HIF-1? were reduced in response to chronic mild decreased oxygen and were not full restored after oxygen normalization. Conclusion These data suggest that HIF signaling may be contributing to the pathogenesis of endothelial dysfunction and that normalization of oxygen levels may not be enough to reduce vascular stress.

Green Dixy E

2007-01-01

249

Effect of the long-term memory on the beam break-up instability of a single bunch in storage rings  

International Nuclear Information System (INIS)

We study modifications of the beam break-up instability of transverse coherent oscillations of a single bunch which occur in storage rings due to weak wakefields decaying longer than the revolution period of particles. The long-term part of the wake results in the eigenmode spectra of coherent oscillations. Both stable and unstable modes are found for coherent oscillations of a monochromatic bunch. The single turn wakefields result in the beam break-up coherent oscillations of the bunch. The found eigenmode spectrum does not contain a leading unstable mode. Despite the exponential increase in time of the eigenmodes, both self-consistent and the beam break-up parts of the coherent oscillations indicate similar and non-exponential time dependencies. The beam break-up behavior dominates, if the wake memory is weak.

250

Long-term exposure to low frequency electro-magnetic fields of 50- and 217-Hz leads to learning and memory deficits in mice  

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Full Text Available Electromagnetic field (EMF radiation affects cellular and brain chemistry and function, resulting in deleterious effects such as free radicals formation, impaired DNA repair, reduced melatonin and blood brain barrier protection, and defects on learning and memory and other higher brain functions. In this paper the effects of low frequency EMF of 50- and 217 Hz, ranges often associated with common electronic devices such as televisions and cell phones were examined on learning and memory in adult male mice. Five groups (n=10 mice/group of mice (1 control and 4 experimental were initially trained for the passive avoidance (PA test. They were then placed in devices creating EMF radiation with varying intensities (0.5 to 2 milli-Tesla, mT and frequencies (50- and 217-Hz for 2-weeks (16 hrs/day. Control mice received no radiation. Learning and memory was tested by the PA test and evaluated based on the following parameters: mean step through latency (STL, number of crossing (Cr# and time in dark compartment (TDC. Results showed significant deficiencies in learning and memory in the EM-exposed mice compared to controls: mean STL decreased significantly (p<0.001 in the 50 Hz group (1 and 1.5 mT intensities. In the 217 Hz group, STL also decreased in the 0.5 and 2 mT groups (p< 0.05. There was a notable increase in mean Cr# for both groups and TDC for 50 Hz group. Results confirm that long-term exposure to EMF radiation of 50 and 217 Hz, imparts significant harmful changes on memory and learning, reiterating the need for preventive measures against such exposures.

Soheila Khodakarim

2012-01-01

251

2D Thermoluminescence imaging of dielectric surface long term charge memory of plasma surface interaction in DBD discharges  

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The charge trapping effect due to the exposure of alumina surfaces to plasma has been studied in a volume dielectric barrier discharge (DBD) in Ar and He noble gases. The long lasting charge trapping of alumina dielectric plates, used as barriers in DBDs, is evidenced by an ex situ thermoluminescence (TL) experiment performed with a standard and a custom two-dimensional (2D)-TL apparatus. The spatial density of trapped surface charges is found to be strongly correlated to the plasma morphology, and the surface spatial memory lasted for several minutes to hours after plasma exposure. In the case of Ar, the plasma channel impact signature on the surface shows a higher equivalent radiation dose with respect to the surface plasma wave and the post-discharge species signature. As a consequence, for the development of discharges, inside the dielectric surface the availability of lower energy trapped electrons is larger in the first region of plasma impact. The reported spatial memory increases the likelihood of the occurrence of plasma filaments in the same position in different runs. In He plasmas, the dielectric barrier shows an almost uniform distribution of trapped charges, meaning that there is no preferred region for the development of the discharge. In all cases a slight asymmetry was shown in the direction of the gas flow. This can be interpreted as being due to the long-living species moving in the direction of the gas flow, corresponding with the TL side experiment on the sample exposed to the plasma afterglow. The maximum values and the integral of the 2D-TL images showed a linear relation with the total charge per ac cycle, corresponding with findings for the TL glow curve. In conclusion, 2D-TL images allow the retrieval of information regarding the plasma surface interaction such as the plasma morphology, trap sites and their activation temperature.

Ambrico, Paolo F.; Ambrico, Marianna; Schiavulli, Luigi; De Benedictis, Santolo

2014-07-01

252

Long-Term Electrophysiological and Behavioral Analysis on the Improvement of Visual Working Memory Load, Training Gains, and Transfer Benefits  

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Full Text Available Recent evidence demonstrates that with training, one can enhance visual working memory (VWM capacity and attention over time in the near transfer tasks. Not only do these studies reveal the characteristics of VWM load and the influences of training, they may also provide insights into developing effective rehabilitation for patients with VWM deficiencies. However, few studies have investigated VWM over extended periods of time and evaluated transfer benefits on non-trained tasks. Here, we combined behavioral and electroencephalographical approaches to investigate VWM load, training gains, and transfer benefits. Our results reveal that VWM capacity is directly correlated to the difference of event-related potential waveforms. In particular, the “magic number 4” can be observed through the contralateral delay amplitude and the average capacity is 3.25-item over 15 participants. Furthermore, our findings indicate that VWM capacity can be improved through training; and after training exercises, participants from the training group are able to dramatically improve their performance. Likewise, the training effects on non-trained tasks can also be observed at the 12th week after training. Therefore, we conclude that participants can benefit from training gains, and augmented VWM capacity sustained over long periods of time on specific variety of tasks.

Ching-Chang Kuo

2014-05-01

253

Gulf war agent exposure causes impairment of long-term memory formation and neuropathological changes in a mouse model of gulf war illness.  

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Gulf War Illness (GWI) is a chronic multisymptom illness with a central nervous system component such as memory deficits, neurological, and musculoskeletal problems. There are ample data that demonstrate that exposure to Gulf War (GW) agents, such as pyridostigmine bromide (PB) and pesticides such as permethrin (PER), were key contributors to the etiology of GWI post deployment to the Persian GW. In the current study, we examined the consequences of acute (10 days) exposure to PB and PER in C57BL6 mice. Learning and memory tests were performed at 18 days and at 5 months post-exposure. We investigated the relationship between the cognitive phenotype and neuropathological changes at short and long-term time points post-exposure. No cognitive deficits were observed at the short-term time point, and only minor neuropathological changes were detected. However, cognitive deficits emerged at the later time point and were associated with increased astrogliosis and reduction of synaptophysin staining in the hippocampi and cerebral cortices of exposed mice, 5 months post exposure. In summary, our findings in this mouse model of GW agent exposure are consistent with some GWI symptom manifestations, including delayed onset of symptoms and CNS disturbances observed in GWI veterans. PMID:25785457

Zakirova, Zuchra; Tweed, Miles; Crynen, Gogce; Reed, Jon; Abdullah, Laila; Nissanka, Nadee; Mullan, Myles; Mullan, Michael J; Mathura, Venkatarajan; Crawford, Fiona; Ait-Ghezala, Ghania

2015-01-01

254

Signaling through cGMP-dependent protein kinase I in the amygdala is critical for auditory-cued fear memory and long-term potentiation.  

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Long-term potentiation (LTP) of inputs relaying sensory information from cortical and thalamic neurons to principal neurons in the lateral amygdala (LA) is thought to serve as a cellular mechanism for associative fear learning. Nitric oxide (NO), a messenger molecule widely implicated in synaptic plasticity and behavior, has been shown to enhance LTP in the LA as well as consolidation of associative fear memory. Additional evidence suggests that NO-induced enhancement of LTP and amygdala-dependent learning requires signaling through soluble guanylyl cyclase (sGC) and cGMP-dependent protein kinase (cGK). Mammals possess two genes for cGK: the prkg1 gene gives rise to the cGK type I isoforms, cGKIalpha and cGKIbeta, and the prkg2 gene encodes the cGK type II. Reportedly, both cGKI and cGKII are expressed in the amygdala, and cGKII is involved in controlling anxiety-like behavior. Because selective pharmacological tools for individual cGK isoforms are lacking, we used different knock-out mouse models to examine the function of cGKI and cGKII for LTP in the LA and pavlovian fear conditioning. We found robust expression of the cGKI specifically in the LA with cGKIbeta as the prevailing isoform. We further show a marked reduction of LTP at both thalamic and cortical inputs to the LA and a selective impairment of auditory-cued fear memory in cGKI-deficient mutants. In contrast, cGKII null mutants lack these phenotypes. Our data suggest a function of cGKI, likely the beta isoform, in the LA, supporting synaptic plasticity and consolidation of fear memory. PMID:19109502

Paul, Cindy; Schöberl, Florian; Weinmeister, Pascal; Micale, Vincenzo; Wotjak, Carsten T; Hofmann, Franz; Kleppisch, Thomas

2008-12-24

255

Non-word repetition in children with specific language impairment: a deficit in phonological working memory or in long-term verbal knowledge?  

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In this study we investigated the effects of long-term memory (LTM) verbal knowledge on short-term memory (STM) verbal recall in a sample of Italian children affected by different subtypes of specific language impairment (SLI). The aim of the study was to evaluate if phonological working memory (PWM) abilities of SLI children can be supported by LTM linguistic representations and if PWM performances can be differently affected in the various subtypes of SLI. We tested a sample of 54 children affected by Mixed Receptive-Expressive (RE), Expressive (Ex) and Phonological (Ph) SLI (DSM-IV - American Psychiatric Association, 1994) by means of a repetition task of words (W) and non-words (NW) differing in morphemic structure [morphological non-words (MNW), consisting of combinations of roots and affixes - and simple non-words - with no morphological constituency]. We evaluated the effects of lexical and morpho-lexical LTM representations on STM recall by comparing the repetition accuracy across the three types of stimuli. Results indicated that although SLI children, as a group, showed lower repetition scores than controls, their performance was affected similarly to controls by the type of stimulus and the experimental manipulation of the non-words (better repetition of W than MNW and NW, and of MNW than NW), confirming the recourse to LTM verbal representations to support STM recall. The influence of LTM verbal knowledge on STM recall in SLI improved with age and did not differ among the three types of SLI. However, the three types of SLI differed in the accuracy of their repetition performances (PMW abilities), with the Phonological group showing the best scores. The implications for SLI theory and practice are discussed. PMID:17710828

Casalini, Claudia; Brizzolara, Daniela; Chilosi, Anna; Cipriani, Paola; Marcolini, Stefania; Pecini, Chiara; Roncoli, Silvia; Burani, Cristina

2007-08-01

256

Beta-adrenergic receptors link NO/sGC/PKG signaling to BDNF expression during the consolidation of object recognition long-term memory.  

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The nitric oxide (NO)/soluble guanylyl cyclase (sGC)/protein kinase G (PKG) pathway is important for memory processing, but the identity of its downstream effectors as well as its actual participation in the consolidation of nonaversive declarative long-term memory (LTM) remain unknown. Here, we show that training rats in an object recognition (OR) learning task rapidly increased nitrites/nitrates (NOx) content in the CA1 region of the dorsal hippocampus while posttraining intra-CA1 microinfusion of the neuronal NO synthase (nNOS) inhibitor L-NN hindered OR LTM retention without affecting memory retrieval or other behavioral variables. The amnesic effect of L-NN was not state dependent, was mimicked by the sGC inhibitor LY83583 and the PKG inhibitor KT-5823, and reversed by coinfusion of the NO donor S-nitroso-N-acetylpenicillamine (SNAP) and the PKG activator 8-bromoguanosine 3',5'-cyclic monophosphate (8Br-cGMP). SNAP did not affect the amnesic effect of LY83583 and KT-5823. Conversely, 8Br-cGMP overturned the amnesia induced by LY83583 but not that caused by KT-5823. Intra-CA1 infusion of the beta-adrenergic receptor blocker timolol right after training hindered OR LTM and, although coadministration of noradrenaline reversed the amnesia caused by L-NN, LY83583, and KT5823, the amnesic effect of timolol was unaffected by coinfusion of 8Br-cGMP or SNAP, indicating that hippocampal beta-adrenergic receptors act downstream NO/sGC/PKG signaling. We also found that posttraining intra-CA1 infusion of function-blocking anti-brain-derived neurotrophic factor (BDNF) antibodies hampered OR LTM retention, whereas OR training increased CA1 BDNF levels in a nNOS- and beta-adrenergic receptor-dependent manner. Taken together, our results demonstrate that NO/sGC/PKG signaling in the hippocampus is essential for OR memory consolidation and suggest that beta-adrenergic receptors link the activation of this pathway to BDNF expression during the consolidation of declarative memories. PMID:19533679

Furini, Cristiane R; Rossato, Janine I; Bitencourt, Lucas L; Medina, Jorge H; Izquierdo, Iván; Cammarota, Martín

2010-05-01

257

The Sun Has A Short Memory: Turbulent Pumping Of Magnetic Flux Reduces Solar Cycle Memory And Precludes Long-term Predictions  

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Predicting the activity of the Sun is important because of its effect on space environmental conditions and climate. However, recent efforts to predict the amplitude of the solar cycle have resulted in diverging forecasts with no consensus. It is understood that the dynamical memory of the solar dynamo mechanism governs predictability and this memory is different for advection- and diffusion-dominated solar convection zones. By utilizing stochastically forced, kinematic dynamo simulations, we demonstrate that the inclusion of downward turbulent pumping of magnetic flux reduces the memory of both advection- and diffusion-dominated solar dynamos to only one cycle; stronger pumping degrades this memory further. We conclude that the dynamical memory of the solar cycle is short; reliable predictions for the maximum of solar activity can be made only at the preceding minimum which explains why early forecasts for the maximum of solar cycle 24 have widely diverged. Our analysis suggests that for more accurate predictions, sequential data assimilation would be necessary in forecasting models to account for the Sun's short memory.

Nandy, Dibyendu; Karak, B. B.

2012-05-01

258

Brevican-Deficient Mice Display Impaired Hippocampal CA1 Long-Term Potentiation but Show No Obvious Deficits in Learning and Memory  

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Brevican is a brain-specific proteoglycan which is found in specialized extracellular matrix structures called perineuronal nets. Brevican increases the invasiveness of glioma cells in vivo and has been suggested to play a role in central nervous system fiber tract development. To study the role of brevican in the development and function of the brain, we generated mice lacking a functional brevican gene. These mice are viable and fertile and have a normal life span. Brain anatomy was normal, although alterations in the expression of neurocan were detected. Perineuronal nets formed but appeared to be less prominent in mutant than in wild-type mice. Brevican-deficient mice showed significant deficits in the maintenance of hippocampal long-term potentiation (LTP). However, no obvious impairment of excitatory and inhibitory synaptic transmission was found, suggesting a complex cause for the LTP defect. Detailed behavioral analysis revealed no statistically significant deficits in learning and memory. These data indicate that brevican is not crucial for brain development but has restricted structural and functional roles. PMID:12370289

Brakebusch, Cord; Seidenbecher, Constanze I.; Asztely, Fredrik; Rauch, Uwe; Matthies, Henry; Meyer, Hannelore; Krug, Manfred; Böckers, Tobias M.; Zhou, Xiaohong; Kreutz, Michael R.; Montag, Dirk; Gundelfinger, Eckart D.; Fässler, Reinhard

2002-01-01

259

Long term effects of murine postnatal exposure to decabromodiphenyl ether (BDE-209) on learning and memory are dependent upon APOE polymorphism and age  

DEFF Research Database (Denmark)

Polybrominated diphenyl ethers (PBDEs) are a group of chemicals widely used as flame retardants; the lower brominated forms (1-5 bromine atoms) are highly neurotoxic and are presently not in commercial use. The highest brominated, the decabromodiphenyl ether (BDE-209) remains in use and its adverse and persistent effects are subject to debate. Of special concern are developmental exposures that can disrupt later-in-life adult health or aging. In this study, we investigated the effects of postnatal exposure to BDE-209 in combination with apolipoprotein E (apoE) genotype, a genetic factor that is associated with varied vulnerability for the development of neurodegenerative diseases. On postnatal day 10, transgenic mice of both sexes carrying apoE2, apoE3 and apoE4 were orally exposed to 0, 10 or 30mg/kg of BDE-209. Spatial reference memory was assessed in a Morris Water Maze (MWM) task at 4 and 12months of age. The levels of the brain-derived neurotrophic factor (BDNF) were determined in hippocampus and frontalcortex of mice at 5months of age. Mice carrying different apoE polymorphisms showed differences in the acquisition and retention of the spatial navigation task both at 4 and 12months of age. Postnatal exposure to BDE-209 induced long term effects in spatial learning, which were dependent upon age, sex and apoE genotype; these effects were more evident in apoE3 mice. BDNF levels were lower in the frontal cortex of apoE4 mice and higher in the hippocampus of exposed mice, independent of the genotype. The results of the present study provide evidence of long-lasting effects in spatial learning and memory after early exposure to BDE-209. Developmental exposure to this neurotoxicant may contribute to cognitive decline and abnormal aging.

Reverte, Ingrid; Klein, Anders Bue

2014-01-01

260

Long term effects of murine postnatal exposure to decabromodiphenyl ether (BDE-209) on learning and memory are dependent upon APOE polymorphism and age.  

Science.gov (United States)

Polybrominated diphenyl ethers (PBDEs) are a group of chemicals widely used as flame retardants; the lower brominated forms (1-5 bromine atoms) are highly neurotoxic and are presently not in commercial use. The highest brominated, the decabromodiphenyl ether (BDE-209) remains in use and its adverse and persistent effects are subject to debate. Of special concern are developmental exposures that can disrupt later-in-life adult health or aging. In this study, we investigated the effects of postnatal exposure to BDE-209 in combination with apolipoprotein E (apoE) genotype, a genetic factor that is associated with varied vulnerability for the development of neurodegenerative diseases. On postnatal day 10, transgenic mice of both sexes carrying apoE2, apoE3 and apoE4 were orally exposed to 0, 10 or 30mg/kg of BDE-209. Spatial reference memory was assessed in a Morris Water Maze (MWM) task at 4 and 12months of age. The levels of the brain-derived neurotrophic factor (BDNF) were determined in hippocampus and frontal cortex of mice at 5months of age. Mice carrying different apoE polymorphisms showed differences in the acquisition and retention of the spatial navigation task both at 4 and 12months of age. Postnatal exposure to BDE-209 induced long term effects in spatial learning, which were dependent upon age, sex and apoE genotype; these effects were more evident in apoE3 mice. BDNF levels were lower in the frontal cortex of apoE4 mice and higher in the hippocampus of exposed mice, independent of the genotype. The results of the present study provide evidence of long-lasting effects in spatial learning and memory after early exposure to BDE-209. Developmental exposure to this neurotoxicant may contribute to cognitive decline and abnormal aging. PMID:23999552

Reverte, Ingrid; Klein, Anders B; Domingo, José L; Colomina, Maria Teresa

2013-01-01

261

Long-term collections  

CERN Multimedia

The Committee of the Long Term Collections (CLT) asks for your attention for the following message from a young Peruvian scientist, following the earthquake which devastated part of her country a month ago.

Collectes à long terme

2007-01-01

262

Transcranial focal electrical stimulation via tripolar concentric ring electrodes does not modify the short- and long-term memory formation in rats evaluated in the novel object recognition test  

OpenAIRE

Noninvasive transcranial focal electrical stimulation (TFS) via tripolar concentric ring electrodes (TCREs) has been under development by Besio as an alternative/complementary therapy for seizure control. TFS has shown efficacy attenuating penicillin, pilocarpine, and pentylenetetrazole– induced acute seizures in rat models. This study evaluated the effects of TFS via TCREs on the memory formation of healthy rats as a safety test of TFS. The short and long-term memory formation was tested a...

Rogel-salazar, G.; Luna-mungui?a, H.; Stevens, Ke; Besio, Wg

2013-01-01

263

Working memory training shows immediate and long-term effects on cognitive performance in children [v3; ref status: indexed, http://f1000r.es/4y9  

Directory of Open Access Journals (Sweden)

Full Text Available Working memory is important for mental reasoning and learning processes. Several studies in adults and school-age children have shown performance improvement in cognitive tests after working memory training. Our aim was to examine not only immediate but also long-term effects of intensive working memory training on cognitive performance tests in children. Fourteen healthy male subjects between 10 and 16 years trained a visuospatial n-back task over 3 weeks (30 min daily, while 15 individuals of the same age range served as a passive control group. Significant differences in immediate (after 3 weeks of training and long-term effects (after 2-6 months in an auditory n-back task were observed compared to controls (2.5 fold immediate and 4.7 fold long-term increase in the training group compared to the controls. The improvement was more pronounced in subjects who improved their performance during the training. Other cognitive functions (matrices test and Stroop task did not change when comparing the training group to the control group. We conclude that visuospatial working memory training in children boosts performance in similar memory tasks such as the auditory n-back task. The sustained performance improvement several months after the training supports the effectiveness of the training.

Fiona Pugin

2015-01-01

264

Striatal signaling in L-DOPA-induced dyskinesia: common mechanisms with drug abuse and long term memory involving D1 dopamine receptor stimulation  

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Full Text Available Parkinson’s disease is a common neurodegenerative disorder caused by the degeneration of midbrain substantia nigra dopaminergic neurons that project to the striatum. Despite extensive investigation aimed at finding new therapeutic approaches, the dopamine precursor molecule, 3,4-dihydroxyphenyl-L-alanine (L-DOPA, remains the most effective and commonly used treatment. However, chronic treatment and disease progression lead to changes in the brain’s response to L-DOPA, resulting in decreased therapeutic effect and the appearance of dyskinesias. L-DOPA-induced dyskinesia (LID interferes significantly with normal motor activity and persists unless L-DOPA dosages are reduced to below therapeutic levels. Thus, controlling LID is one of the major challenges in Parkinson’s disease therapy. LID is the result of intermittent stimulation of supersensitive D1 dopamine receptors located in the very severely denervated striatal neurons. Through increased coupling to G?olf, resulting in greater stimulation of adenylyl-cyclase, D1 receptors phosphorylate DARPP-32 and other protein kinase A targets. Moreover, D1 receptor stimulation activates ERK and triggers a signaling pathway involving mTOR and modifications of histones that results in changes in translation, chromatin modification and gene transcription. In turn, sensitization of D1 receptor signaling causes a widespread increase in the metabolic response to D1 agonists and changes in the activity of basal ganglia neurons that correlate with the severity of LID. Importantly, different studies suggest that dyskinesias may share mechanisms with drug abuse and long term memory involving D1 receptor activation. Here we review evidence implicating D1 receptor signaling in the genesis of LID, analyze mechanisms that may translate enhanced D1 signaling into dyskinetic movements, and discuss the possibility that the mechanisms underlying LID are not unique to the Parkinson’s disease brain.

MarioGustavoMurer

2011-08-01

265

Immunization of mice with the nef gene from Human Immunodeficiency Virus type 1: Study of immunological memory and long-term toxicology  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The human immunodeficiency virus type 1 (HIV-1 regulatory protein, Nef, is an attractive vaccine target because it is involved in viral pathogenesis, is expressed early in the viral life cycle and harbors many T and B cell epitopes. Several clinical trials include gene-based vaccines encoding this protein. However, Nef has been shown to transform certain cell types in vitro. Based on these findings we performed a long-term toxicity and immunogenicity study of Nef, encoded either by Modified Vaccinia virus Ankara or by plasmid DNA. BALB/c mice were primed twice with either DNA or MVA encoding Nef and received a homologous or heterologous boost ten months later. In the meantime, the Nef-specific immune responses were monitored and at the time of sacrifice an extensive toxicological evaluation was performed, where presence of tumors and other pathological changes were assessed. Results The toxicological evaluation showed that immunization with MVAnef is safe and does not cause cellular transformation or other toxicity in somatic organs. Both DNAnef and MVAnef immunized animals developed potent Nef-specific cellular responses that declined to undetectable levels over time, and could readily be boosted after almost one year. This is of particular interest since it shows that plasmid DNA vaccine can also be used as a potent late booster of primed immune responses. We observed qualitative differences between the T cell responses induced by the two different vectors: DNA-encoded nef induced long-lasting CD8+ T cell memory responses, whereas MVA-encoded nef induced CD4+ T cell memory responses. In terms of the humoral immune responses, we show that two injections of MVAnef induce significant anti-Nef titers, while repeated injections of DNAnef do not. A single boost with MVAnef could enhance the antibody response following DNAnef prime to the same level as that observed in animals immunized repeatedly with MVAnef. We also demonstrate the possibility to boost HIV-1 Nef-specific immune responses using the MVAnef construct despite the presence of potent anti-vector immunity. Conclusion This study shows that the nef gene vectored by MVA does not induce malignancies or other adverse effects in mice. Further, we show that when the nef gene is delivered by plasmid or by a viral vector, it elicits potent and long-lasting immune responses and that these responses can be directed towards a CD4+ or a CD8+ T cell response depending on the choice of vector.

Engström Gunnel

2007-07-01

266

Antidepressant Suppression of Non-REM Sleep Spindles and REM Sleep Impairs Hippocampus-Dependent Learning While Augmenting Striatum-Dependent Learning  

OpenAIRE

Rapid eye movement (REM) sleep enhances hippocampus-dependent associative memory, but REM deprivation has little impact on striatum-dependent procedural learning. Antidepressant medications are known to inhibit REM sleep, but it is not well understood if antidepressant treatments impact learning and memory. We explored antidepressant REM suppression effects on learning by training animals daily on a spatial task under familiar and novel conditions, followed by training on a procedural memory ...

Watts, Alain; Gritton, Howard J.; Sweigart, Jamie; Poe, Gina R.

2012-01-01

267

Long-Term Collections  

CERN Multimedia

It is the time of the year when our fireman colleagues go around the laboratory for their traditional calendars sale. A part of the money of the sales will be donated in favour of the long-term collections. We hope that you will welcome them warmly.

Comité des collectes à long terme

2011-01-01

268

The effect of estrogen synthesis inhibition on hippocampal memory.  

Science.gov (United States)

17-Beta-estradiol (E2) facilitates long term-potentiation (LTP) and increases spine synapse density in hippocampal neurons of ovariectomized rodents. Consistent with these beneficial effects on the cellular level, E2 improves hippocampus-dependent memory. A prominent approach to study E2 effects in rodents is the inhibition of its synthesis by letrozole, which reduces LTPs and spine synapse density. In the current longitudinal functional magnetic resonance imaging (fMRI) study, we translated this approach to humans and compared the impact of E2 synthesis inhibition on memory performance and hippocampal activity in post-menopausal women taking letrozole (n=21) to controls (n=24). In particular, we employed various behavioral memory paradigms that allow the disentanglement of hippocampus-dependent and -independent memory. Consistent with the literature on rodents, E2 synthesis inhibition specifically impaired hippocampus-dependent memory, however, this did not apply to the same degree to all of the employed paradigms. On the neuronal level, E2 depletion tended to decrease hippocampal activity during encoding, whereas it increased activity in the anterior cingulate and the dorsolateral prefrontal cortex. We thus infer that the inhibition of E2 synthesis specifically impairs hippocampal functioning in humans, whereas the increased prefrontal activity presumably reflects a compensatory mechanism, which is already known from studies on cognitive aging and Alzheimer's disease. PMID:25863445

Bayer, Janine; Rune, Gabriele; Schultz, Heidrun; Tobia, Michael J; Mebes, Imke; Katzler, Olaf; Sommer, Tobias

2015-06-01

269

Collectes à long terme  

CERN Multimedia

En cette fin d’année 2014 qui approche à grands pas, le Comité des Collectes à Long Terme remercie chaleureusement ses fidèles donatrices et donateurs réguliers pour leurs contributions à nos actions en faveur des plus démunis de notre planète. C’est très important, pour notre Comité, de pouvoir compter sur l’appui assidu que vous nous apportez. Depuis plus de 40 ans maintenant, le modèle des CLT est basé principalement sur des actions à long terme (soit une aide pendant 4-5 ans par projet, mais plus parfois selon les circonstances), et sa planification demande une grande régularité de ses soutiens financiers. Grand MERCI à vous ! D’autres dons nous parviennent au cours de l’année, et ils sont aussi les bienvenus. En particulier, nous tenons à remercier...

Collectes à long terme

2014-01-01

270

Age-related defects in spatial memory are correlated with defects in the late phase of hippocampal long-term potentiation in vitro and are attenuated by drugs that enhance the cAMP signaling pathway  

OpenAIRE

To study the physiological and molecular mechanisms of age-related memory loss, we assessed spatial memory in C57BL/B6 mice from different age cohorts and then measured in vitro the late phase of hippocampal long-term potentiation (L-LTP). Most young mice acquired the spatial task, whereas only a minority of aged mice did. Aged mice not only made significantly more errors but also exhibited greater individual differences. Slices from the hippocampus of aged mice exhibited significantly reduce...

Bach, Mary Elizabeth; Barad, Mark; Son, Hyeon; Zhuo, Min; Lu, Yun-fei; Shih, Robert; Mansuy, Isabelle; Hawkins, Robert D.; Kandel, Eric R.

1999-01-01

271

Redintegration and the Benefits of Long-Term Knowledge in Verbal Short-Term Memory: An Evaluation of Schweickert's (1993) Multinomial Processing Tree Model  

Science.gov (United States)

The impact of four long-term knowledge variables on serial recall accuracy was investigated. Serial recall was tested for high and low frequency words and high and low phonotactic frequency nonwords in 2 groups: monolingual English speakers and French-English bilinguals. For both groups the recall advantage for words over nonwords reflected more…

Thorn, Annabel S. C.; Gathercole, Susan E.; Frankish, Clive R.

2005-01-01

272

[Stapedectomy: long term results].  

Science.gov (United States)

Stapedectomy, with its most innovatory variations, constitutes the treatment of choice for otoesclerosis. Short term results are spectacular, getting GAP closures of less than 5 dB approximatelly in 94% patients, variations depending on the authors. Long term follow up check results show a gradual auditory deterioration. The aim of this study is to audiometric evolution of patients operated of stapedectomy 7 to 10 years ago in our department and to correlate the results with those obtained by other authors, in an attempt to unify conclusions. PMID:12185900

Hernández Montero, E; Fraile Rodrigo, J; Marín Garrido, C; Sampériz, L Carmen; Llorente Arenas, E; Naya Gálvez, M J; Ortiz García, A

2002-04-01

273

Long-term conditions.  

Science.gov (United States)

Technology enabled care services (TECS), which include technologies such as telehealth, telecare, telemedicine and self-care apps, are designed to help people manage long-term conditions and retain as much independence as possible. The NHS Commissioning Assembly has published TECS Resource for Commissioners, a toolkit that raises awareness of the range of TECS available and their benefits to patients and professionals, supports commissioners to collaborate with providers to implement TECS, and advises how to create a TECS strategy, oversee implementation plans and ensure effective evaluation. The publication is at tinyurl.com/khsebyr. PMID:25806457

2015-03-25

274

Changes in Heart Rate Variability Are Associated with Expression of Short-Term and Long-Term Contextual and Cued Fear Memories  

OpenAIRE

Heart physiology is a highly useful indicator for measuring not only physical states, but also emotional changes in animals. Yet changes of heart rate variability during fear conditioning have not been systematically studied in mice. Here, we investigated changes in heart rate and heart rate variability in both short-term and long-term contextual and cued fear conditioning. We found that while fear conditioning could increase heart rate, the most significant change was the reduction in heart ...

Liu, Jun; Wei, Wei; Kuang, Hui; Zhao, Fang; Tsien, Joe Z.

2013-01-01

275

Long-Term and Memory Immune Responses in Mice against Newcastle Disease Virus-Like Particles Containing Respiratory Syncytial Virus Glycoprotein Ectodomains  

OpenAIRE

Although respiratory syncytial virus (RSV) is a significant human pathogen, no RSV vaccines are available. We have reported that a virus-like particle (VLP) RSV vaccine candidate stimulated, in mice, robust, protective anti-RSV glycoprotein TH1 biased immune responses without enhanced respiratory disease upon RSV challenge. We report here an analysis of long-term responses to these VLPs. BALB/c mice immunized, without adjuvant, with VLPs or with infectious RSV generated anti-F and anti-G prot...

Schmidt, Madelyn R.; Mcginnes, Lori W.; Kenward, Sarah A.; Willems, Kristen N.; Woodland, Robert T.; Morrison, Trudy G.

2012-01-01

276

Long term morphological modelling  

DEFF Research Database (Denmark)

A morphological modelling concept for long term nearshore morphology is proposed and examples of its application are presented and discussed. The model concept combines parameterised representations of the cross-shore morphology, with a 2DH area model for waves, currents and sediment transport in the surf zone. Two parameterization schemes are tested for two different morphological phenomena: 1) Shoreline changes due to the presence of coastal structures and 2) alongshore migration of a nearshore nourishment and a bar by-passing a harbour. In the case of the shoreline evolution calculations, a concept often used in one-line modelling of cross-shore shifting of an otherwise constant shape cross-shore profile is applied for the case of a groyne and a detached breakwater. In the case of alongshore bar/nourishment migration an alternative parameterization is adopted. All examples are presented, analysed and discussed with respect to the question of realistic representation, time scale and general applicability ofthe model concept.

Kristensen, Sten EsbjØrn Technical University of Denmark,

2010-01-01

277

Mice Overexpressing Type 1 Adenylyl Cyclase Show Enhanced Spatial Memory Flexibility in the Absence of Intact Synaptic Long-Term Depression  

Science.gov (United States)

There is significant interest in understanding the contribution of intracellular signaling and synaptic substrates to memory flexibility, which involves new learning and suppression of obsolete memory. Here, we report that enhancement of Ca[superscript 2+]-stimulated cAMP signaling by overexpressing type 1 adenylyl cyclase (AC1) facilitated…

Zhang, Ming; Wang, Hongbing

2013-01-01

278

Long-term acarbose administration alleviating the impairment of spatial learning and memory in the SAMP8 mice was associated with alleviated reduction of insulin system and acetylated H4K8.  

Science.gov (United States)

Age-associated memory impairment (AAMI) not only reduces the quality of life for the elderly but also increases the costs of healthcare for society. Methods that can regulate glucose metabolism, insulin/insulin-like growth factor 1 (IGF-1) system and acetylated histone H4 lysine 8 (H4K8ac), one of the most well-researched facets of histone acetylation modification associating with cognition, tend to ameliorate the AAMI. Here, we used SAMP8 mice, the excellent animal model of aging and AAMI, to study the effect of long-term treatment with acarbose, an inhibitor of a-glucosidase, on AAMI and explore whether blood glucose, insulin/IGF-1 system and H4K8ac are associated with potential effects. The treatment group received acarbose (20mg/kg/d, dissolved in drinking water) at the age of 3-month until 9-month old before the behavioral test, and the controls only received water. Compared to the young controls (3-month-old, n=11), the old group (9-month-old, n=8) had declined abilities of spatial learning and memory and levels of serum insulin, hippocampal insulin receptors (InsRs) and H4K8ac. Interestingly, the acarbose group (9-month-old, n=9) showed better abilities of spatial learning and memory and higher levels of insulin, InsRs and H4K8ac relative to the old controls. Good performance of spatial learning and memory was positively correlated with the elevated insulin, InsRs and H4K8ac. All these results suggested that long-term administration of acarbose could alleviate the age-related impairment of spatial learning and memory in the SAMP8 mice, and the alleviated reduction of an insulin system and H4K8ac might be associated with the alleviation. PMID:25645154

Yan, Wen-Wen; Chen, Gui-Hai; Wang, Fang; Tong, Jing-Jing; Tao, Fei

2015-04-01

279

Evaluating long term forecasts  

International Nuclear Information System (INIS)

The U.S. Department of Energy's Energy Information Administration (EIA), and its predecessor organizations, has published projections of U.S. energy production, consumption, distribution and prices annually for over 30 years. A natural issue to raise in evaluating the projections is an assessment of their accuracy compared to eventual outcomes. A related issue is the determination of the sources of 'error' in the projections that are due to differences between the actual versus realized values of the associated assumptions. One way to do this would be to run the computer-based model from which the projections are derived at the time the projected values are realized, using actual rather than assumed values for model assumptions; and, compare these results to the original projections. For long term forecasts, this approach would require that the model's software and hardware configuration be archived and available for many years, possibly decades, into the future. Such archival creates many practical problems; and, in general, it is not being done. This paper reports on an alternative approach for evaluating the projections. In the alternative approach, the model is run many times for cases in which important assumptions are changed individually and in combinations. A database is assembled from the solutions and a regression analysis is conducted for each important projected variable with the associated assumptions chosen as exogenous variables. When actual data are evogenous variables. When actual data are eventually available, the regression results are then used to estimate the sources of the differences in the projections of the endogenous variables compared to their eventual outcomes. The results presented here are for residential and commercial sector natural gas and electricity consumption. (author)

280

Rapid and Reversible Impairments of Short- and Long-Term Social Recognition Memory Are Caused by Acute Isolation of Adult Rats via Distinct Mechanisms  

OpenAIRE

Mammalian social organizations require the ability to recognize and remember individual conspecifics. This social recognition memory (SRM) can be examined in rodents using their innate tendency to investigate novel conspecifics more persistently than familiar ones. Here we used the SRM paradigm to examine the influence of housing conditions on the social memory of adult rats. We found that acute social isolation caused within few days a significant impairment in acquisition of short-term SRM ...

Shahar-gold, Hadar; Gur, Rotem; Wagner, Shlomo

2013-01-01

281

LONG TERM COLLECTIONS  

CERN Multimedia

The Committee would like to thank all those, from near and far, who kindly gave donations to the collection organized at the time of the sudden death of our friend and colleague Stephen O'NEALE The sum of 3,615 francs will be sent to the INEPE Association for the education of children in Quito, Ecuador. We are deeply grateful for this gesture from Steve's family and hope that they find comfort in knowing that Steve's memory will live on through the children whose daily lives will be improved by this gift.

2004-01-01

282

The Timing of Learning before Night-Time Sleep Differentially Affects Declarative and Procedural Long-Term Memory Consolidation in Adolescents  

Science.gov (United States)

Sleep after learning has been shown to foster the consolidation of new memories. However, fundamental questions on the best timing of learning before night-time sleep persist. We tested the hypothesis that learning directly prior to night-time sleep compared to 7.5 hrs prior to night-time sleep provides better conditions for the consolidation of declarative and procedural memories. Fifty healthy female adolescents (aged 16–17 years) were trained on a declarative word-pair and a procedural finger-tapping task at 3 pm (afternoon group, n?=?25) or at 9 pm (evening group, n?=?25), followed by a sleep laboratory night. Retrieval was assessed 24 hours and 7 days after initial training. Subjects trained in the afternoon showed a significantly elevated retention rate of word-pairs compared to subjects trained in the evening after 24 hours, but not after 7 days. In contrast, off-line gains in finger-tapping performance were significantly higher in subjects trained in the evening compared to those trained in the afternoon after both retention intervals. The observed enhanced consolidation of procedural memories after training in the evening fits to current models of sleep-related memory consolidation. In contrast, the higher retention of declarative memories after encoding in the afternoon is surprising, appeared to be less robust and needs further investigation. PMID:22808287

Holz, Johannes; Piosczyk, Hannah; Landmann, Nina; Feige, Bernd; Spiegelhalder, Kai; Riemann, Dieter; Nissen, Christoph; Voderholzer, Ulrich

2012-01-01

283

The Timing of Learning before Night-Time Sleep Differentially Affects Declarative and Procedural Long-Term Memory Consolidation in Adolescents  

OpenAIRE

Sleep after learning has been shown to foster the consolidation of new memories. However, fundamental questions on the best timing of learning before night-time sleep persist. We tested the hypothesis that learning directly prior to night-time sleep compared to 7.5 hrs prior to night-time sleep provides better conditions for the consolidation of declarative and procedural memories. Fifty healthy female adolescents (aged 16–17 years) were trained on a declarative word-pair and a procedural f...

Holz, Johannes; Piosczyk, Hannah; Landmann, Nina; Feige, Bernd; Spiegelhalder, Kai; Riemann, Dieter; Nissen, Christoph; Voderholzer, Ulrich

2012-01-01

284

Effects of the uncompetitive NMDA receptor antagonist memantine on hippocampal long-term potentiation, short-term exploratory modulation and spatial memory in awake, freely moving rats.  

Science.gov (United States)

Chronic treatment of adult male F-344 rats (9-12 months old) with therapeutically relevant doses of memantine (30 mg/kg/day in chow for > 8 weeks) increased the maintenance of long-term potentiation of field excitatory postsynaptic potentials from perforant path-granule cell hippocampal synapses recorded in the fascia dentata in vivo. In contrast, there was no effect of memantine on baseline synaptic responses or population spikes. Likewise, short-term exploratory modulation of these hippocampal evoked responses was not different between memantine-treated and control rats. Both groups of rats were able to learn the spatial version of the Morris water task equally well, but the memantine-treated group showed a strong tendency to show more selective spatial search patterns in the training quadrant of the water pool during a final probe trial. As such, these studies provide the first electrophysiological evidence that memantine can increase the durability of synaptic plasticity and provide preclinical confirmation of the cognitive improvement seen with memantine in the treatment of demented patients. PMID:8963448

Barnes, C A; Danysz, W; Parsons, C G

1996-03-01

285

Cyclic nucleotide-gated channels, calmodulin, adenylyl cyclase, and calcium/calmodulin-dependent protein kinase II are required for late, but not early, long-term memory formation in the honeybee.  

Science.gov (United States)

Memory is a dynamic process that allows encoding, storage, and retrieval of information acquired through individual experience. In the honeybee Apis mellifera, olfactory conditioning of the proboscis extension response (PER) has shown that besides short-term memory (STM) and mid-term memory (MTM), two phases of long-term memory (LTM) are formed upon multiple-trial conditioning: an early phase (e-LTM) which depends on translation from already available mRNA, and a late phase (l-LTM) which requires de novo transcription and translation. Here we combined olfactory PER conditioning and neuropharmacological inhibition and studied the involvement of the NO-cGMP pathway, and of specific molecules, such as cyclic nucleotide-gated channels (CNG), calmodulin (CaM), adenylyl cyclase (AC), and Ca(2+)/calmodulin-dependent protein kinase (CaMKII), in the formation of olfactory LTM in bees. We show that in addition to NO-cGMP and cAMP-PKA, CNG channels, CaM, AC, and CaMKII also participate in the formation of a l-LTM (72-h post-conditioning) that is specific for the learned odor. Importantly, the same molecules are dispensable for olfactory learning and for the formation of both MTM (in the minute and hour range) and e-LTM (24-h post-conditioning), thus suggesting that the signaling pathways leading to l-LTM or e-LTM involve different molecular actors. PMID:24741108

Matsumoto, Yukihisa; Sandoz, Jean-Christophe; Devaud, Jean-Marc; Lormant, Flore; Mizunami, Makoto; Giurfa, Martin

2014-05-01

286

A novel T cell-based vaccine capable of stimulating long-term functional CTL memory against B16 melanoma via CD40L signaling  

OpenAIRE

The ultimate goal of antitumor vaccines is to develop memory CD8+ cytotoxic T lymphocytes (CTLs), which are critical mediators of antitumor immunity. We previously demonstrated that the ovalbumin (OVA)-specific CD4+ T cell-based (OVA-TEXO) vaccine generated using OVA-pulsed dendritic cell (DCOVA)-released exosomes (EXOOVA) stimulate CTL responses via IL-2 and costimulatory CD80 signaling. To assess the potential involvement of other costimulatory pathways and to define the key constituent of ...

Xie, Yufeng; Wang, Lu; Freywald, Andrew; Qureshi, Mabood; Chen, Yue; Xiang, Jim

2012-01-01

287

Long-term central and effector SHIV-specific memory T cell responses elicited after a single immunization with a novel lentivector DNA vaccine.  

Science.gov (United States)

Prevention of HIV acquisition and replication requires long lasting and effective immunity. Given the state of HIV vaccine development, innovative vectors and immunization strategies are urgently needed to generate safe and efficacious HIV vaccines. Here, we developed a novel lentivirus-based DNA vector that does not integrate in the host genome and undergoes a single-cycle of replication. Viral proteins are constitutively expressed under the control of Tat-independent LTR promoter from goat lentivirus. We immunized six macaques once only with CAL-SHIV-IN- DNA using combined intramuscular and intradermal injections plus electroporation. Antigen-specific T cell responses were monitored for 47 weeks post-immunization (PI). PBMCs were assessed directly ex vivo or after 6 and 12 days of in vitro culture using antigenic and/or homeostatic proliferation. IFN-? ELISPOT was used to measure immediate cytokine secretion from antigen specific effector cells and from memory precursors with high proliferative capacity (PHPC). The memory phenotype and functions (proliferation, cytokine expression, lytic content) of specific T cells were tested using multiparametric FACS-based assays. All immunized macaques developed lasting peripheral CD8+ and CD4+ T cell responses mainly against Gag and Nef antigens. During the primary expansion phase, immediate effector cells as well as increasing numbers of proliferating cells with limited effector functions were detected which expressed markers of effector (EM) and central (CM) memory phenotypes. These responses contracted but then reemerged later in absence of antigen boost. Strong PHPC responses comprising vaccine-specific CM and EM T cells that readily expanded and acquired immediate effector functions were detected at 40/47 weeks PI. Altogether, our study demonstrated that a single immunization with a replication-limited DNA vaccine elicited persistent vaccine-specific CM and EM CD8+ and CD4+ T cells with immediate and readily inducible effector functions, in the absence of ongoing antigen expression. PMID:25337803

Arrode-Brusés, Géraldine; Moussa, Maha; Baccard-Longere, Monique; Villinger, François; Chebloune, Yahia

2014-01-01

288

Long-term follow-up in patients treated with larynx preservation approach using sequential chemotherapy and radiation therapy: the Memorial Hospital experience  

International Nuclear Information System (INIS)

While many combined modality, organ preservation programs are reported in the literature, few provide long-term follow-up with functional outcomes. The goal of this report is to provide this outcome data for patients treated with a sequential chemotherapy/radiotherapy (CT/RT) approach - the only strategy successfully compared to surgery and RT in randomized trials to date - treated at our institution with a median follow-up of over 10 years. Eligible patients had advanced, resectable, histologically-confirmed squamous cell carcinomas of larynx or pharynx for which standard surgical management would have jeopardized the larynx. Treatment occurred as part of three consecutive larynx preservation protocols and consisted of three cycles of induction, cisplatin-based chemotherapy followed, if the primary site had a major response, by definitive dose radiation therapy (65-70 Gy to sites of initial disease bulk) via conventional fractionation (1.8-2 Gy fraction). If the tumor did not respond to the induction chemotherapy or persisted after radiation therapy, appropriate locoregional treatment was pursued. Response to induction chemotherapy, initial rendered disease-free rate, local control with a functional larynx (without any surgery except biopsy to the primary site, permanent tracheostomy or gastrostomy - LCLP), and actuarial survival rates were calculated. A multivariate assessment of prognostic variables was performed using Cox-proportional hazards model to evaluate forproportional hazards model to evaluate for predictors of successful larynx preservation. One hundred and ten patients (109 evaluable) with cancer of the larynx (40%), hypopharynx (29%), and oropharynx (30%) were enrolled from 1983 to 1990. The median age was 60 years With a median Karnofsky Performance Status of 80%. The stage of the patients consisted of 33% T4, 74% node positive, and 69% stage IV. The major response rate at the primary site to induction chemotherapy was 74% (complete response in 36%). Seventy-eight percent were rendered disease-free by initial chemotherapy, radiation therapy, and surgery as indicated by protocol. Median follow-up for the group was 122 months (range 0.5-204 months). The overall and disease-free survival rates were 35% and 31% at 5-years, and 26% and 31% at 10-years, respectively. Rates for LCLP at 5-and 10-years were 33% and 25%, respectively. T stage and Karnofsky Performance Status were predictive of LCLP. The treatment strategy of induction chemotherapy followed by radiation therapy as described is a feasible and effective method to treat advanced squamous cell carcinomas of the head and neck with larynx preservation intent For the most part, patients who obtained local control with chemotherapy and radiation did not develop significant functional deterioration requiring tracheostomy and/or gastrostomy placement with longer follow-up. (author)

289

Memória de longo prazo modulada pela memória de curto prazo / Long term memory modulated by short term memory / Memoria a largo plazo modulada por la memoria a corto plazo  

Scientific Electronic Library Online (English)

Full Text Available Quando um estímulo ocorre aleatoriamente à esquerda ou à direita, a resposta é mais rápida quando estímulo e resposta estão no mesmo lado (condição compatível) do que em lados opostos (condição incompatível). Na tarefa de Simon, embora a resposta seja selecionada pela forma (ou cor) do estímulo, a p [...] osição deste influencia o Tempo de Reação Manual (TRM). O efeito Simon corresponde à diferença entre as médias dos TRMs nas duas condições (incompatível e compatível). Neste trabalho, estudamos como uma tarefa prévia de compatibilidade realizada com um dedo indicador modula o efeito Simon. Vinte e oito voluntários realizaram uma tarefa de compatibilidade seguida pela tarefa de Simon. No grupo compatível (14 voluntários), encontramos um efeito Simon de 24 ms. No incompatível (14 voluntários), ocorreu um efeito Simon inverso de -16 ms. Estes resultados mostram uma modulação da memória de longo prazo por uma tarefa envolvendo a memória de curto prazo. Abstract in spanish Cuando un estimulo ocurre aleatoriamente a la izquierda o a la derecha, la respuesta es más rápida cuando el estimulo y la respuesta están del mismo lado (condición compatible), de que cuando están en lados opuestos (condición incompatible). En la prueba de Simon, el color o la forma del estímulo de [...] termina la respuesta, pero éste es más rápido cuando hay una correlación espacial entre el estímulo y la respuesta. En este trabajo, estudiamos la modulación del efecto Simon por la tarea de la compatibilidad espacial en la cual uno dedo índice respondió. Veintiocho voluntarios realizaron la prueba de compatibilidad (14 la compatible y 14 la incompatible). Después el voluntario realizó la prueba de Simon. En el grupo compatible, encontramos efecto de Simon de 21 ms. Sin embargo, en el grupo incompatibles, ocurrió un efecto de Simon inverso de -16 ms. Estos resultados demuestran una modulación de la memoria a largo plazo por la memoria a corto plazo. Abstract in english When a stimulus randomly occurs at left or right, the response is faster when stimulus and response are on the same side (compatible condition) than on opposite sides (incompatible condition). In the Simon task, color or shape determines the correct response but it is faster when there is correspond [...] ence between stimulus and response key positions. In this research, we studied the Simon effect modulation through a previous spatial compatibility task in which just one index finger presses the keys. Twenty-eight volunteers run compatibility tasks (14 compatible and 14 incompatible). Then, they performed a Simon task in which the correct response was selected by shape. A Simon effect of 24 ms was found in the compatible group. An inverse Simon effect of -16 ms occurred in the incompatible group. These results show long-term memory modulation by task involving short-term memory.

Viviane, Moreira-Aguiar; Allan Pablo, Lameira; Erick Quintas, Conde; Antônio, Pereira Júnior; Carlo Arrigo, Umiltà; Luiz de Gonzaga, Gawryszewski.

290

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization  

OpenAIRE

At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing, storage, learning, and memory under both physiological and pathological conditions. One widely accepted model of learning mechanism and information processing in the brain is Hebbian Plasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectively activity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid and synapse-...

Park, Joo Min; Jung, Sung-cherl; Eun, Su-yong

2014-01-01

291

Long-term Video-EEG Monitoring for Paroxysmal Events  

OpenAIRE

Background: Long term video-electroencephalography monitoring (VEM) has been widelyused for the diagnosis, classification, and management of seizures. Fewstudies have systemically examined its safety issues and clinical utility. Thisprospective study investigates the general clinical application of long termVEM in the management of paroxysmal events.Methods: This study cohort consisted of patients admitted to the inpatient VEM unit atChang Gung Memorial Hospital (Lin-Kou). Standard 19 channel...

Ying-Ying Lee; Mei-Ying Lee; Yu-Tai Tsai; Chung-Yang Sung; Hsiang-Yao Hsieh; Siew-Na Lim; Peter Wu Hung; Tony Wu; I-an Chen

2009-01-01

292

Basics (Long-Term Care)  

Science.gov (United States)

... navigate the myriad of legal, family, and social dynamics along the way. LTC PathFinder Long-term care ... USA.gov This is an official U.S. government website managed by the U.S. Department of Health & Human ...

293

Simultaneous Training on Two Hippocampus-Dependent Tasks Facilitates Acquisition of Trace Eyeblink Conditioning  

Science.gov (United States)

A common cellular alteration, reduced post-burst afterhyperpolarization (AHP) in CA1 neurons, is associated with acquisition of the hippocampus-dependent tasks trace eyeblink conditioning and the Morris water maze. As a similar increase in excitability is correlated with these two learning paradigms, we sought to determine the interactive…

Lee, Grace; Disterhoft, John F.; Kuo, Amy G.

2006-01-01

294

Comparing long term energy scenarios  

International Nuclear Information System (INIS)

Major projection studies by international organizations and senior analysts have been compared with reference to individual key parameters (population, energy demand/supply, resources, technology, emissions and global warming) to understand trends and implications of the different scenarios. Then, looking at the long term (i.e., 2050 and beyond), parameters and trends have been compared together to understand and quantify whether and when possible crisis or market turbulence might occur due to shortage of resources or environmental problems

295

Long term radioactive waste management  

International Nuclear Information System (INIS)

In France, waste management, a sensitive issue in term of public opinion, is developing quickly, and due to twenty years of experience, is now reaching maturity. With the launching of the French nuclear programme, the use of radioactive sources in radiotherapy and industry, waste management has become an industrial activity. Waste management is an integrated system dealing with the wastes from their production to the long term disposal, including their identification, sortage, treatment, packaging, collection and transport. This system aims at guaranteing the protection of present and future populations with an available technology. In regard to their long term management, and the design of disposals, radioactive wastes are divided in three categories. This classification takes into account the different radioisotopes contained, their half life and their total activity. Presently short-lived wastes are stored in the shallowland disposal of the ''Centre de la Manche''. Set up within the French Atomic Energy Commission (CEA), the National Agency for waste management (ANDRA) is responsible within the framework of legislative and regulatory provisions for long term waste management in France

296

Piccolo knockdown-induced impairments of spatial learning and long-term potentiation in the hippocampal CA1 region.  

Science.gov (United States)

Neurotransmitter release is regulated at a specific site in nerve terminals called the "active zone", which is composed of various cytomatrix proteins such as Piccolo (also known as Aczonin) and Bassoon. These proteins share regions of high sequence similarity and have very high molecular weights (>400 kDa). Since Piccolo knockout mice have not yet been established, the role of Piccolo in the neuronal system remains unclear. In this study, we investigated the effects of Piccolo antisense oligonucleotide injected into the ventricle on hippocampal long-term potentiation (LTP) and learning and memory assessed with the novel object recognition test and the Morris water maze test. There was no significant difference in cognitive memory between Piccolo antisense-treated and vehicle- or sense-treated mice; however, spatial learning in Piccolo antisense-treated mice was impaired but not in sense- or vehicle-treated mice. Next, we investigated LTP formation in these groups in area CA1 and dentate gyrus of the same hippocampal slices. The magnitude of LTP in Piccolo antisense-treated mice was significantly lower than in sense- or vehicle-treated mice, with no change in basal level. Moreover, the level of high K(+)-induced glutamate release in the antisense-treated mice was significantly lower than in sense-treated mice. Taken together, these results indicate that Piccolo plays a pivotal role in synaptic plasticity in area CA1 and in hippocampus-dependent learning in mice, and that the extracellular levels of glutamate in the hippocampus under stimulated conditions are controlled by Piccolo. PMID:19766155

Ibi, Daisuke; Nitta, Atsumi; Ishige, Kumiko; Cen, Xiaobo; Ohtakara, Tomohiro; Nabeshima, Toshitaka; Ito, Yoshihisa

2010-01-01

297

Selective inhibition of phosphodiesterase 5 enhances glutamatergic synaptic plasticity and memory in mice.  

Science.gov (United States)

Phosphodiesterases (PDEs) belong to a family of proteins that control metabolism of cyclic nucleotides. Targeting PDE5, for enhancing cellular function, is one of the therapeutic strategies for male erectile dysfunction. We have investigated whether in vivo inhibition of PDE5, which is expressed in several brain regions, will enhance memory and synaptic transmission in the hippocampus of healthy mice. We have found that acute administration of sildenafil, a specific PDE5 inhibitor, enhanced hippocampus-dependent memory tasks. To elucidate the underlying mechanism in the memory enhancement, effects of sildenafil on long-term potentiation (LTP) were measured. The level of LTP was significantly elevated, with concomitant increases in basal synaptic transmission, in mice treated with sildenafil (1 mg/kg/day) for 15 days compared to control mice. These results suggest that moderate PDE5 inhibition enhances memory by increasing synaptic plasticity and transmission in the hippocampus. PMID:23620198

Uthayathas, Subramaniam; Parameshwaran, Kodeeswaran; Karuppagounder, Senthilkumar S; Ahuja, Manuj; Dhanasekaran, Muralikrishnan; Suppiramaniam, Vishnu

2013-11-01

298

Long term stability of power systems  

Energy Technology Data Exchange (ETDEWEB)

Power system long term stability is still a developing subject. In this paper we provide our perspectives and experiences related to long term stability. The paper begins with the description of the nature of the long term stability problem, followed by the discussion of issues related to the modeling and solution techniques of tools for long term stability analysis. Cases studies are presented to illustrate the voltage stability aspect and plant dynamics aspect of long term stability. (author) 20 refs., 11 figs.

Kundur, P.; Gao, B. [Powertech Labs. Inc., Surrey, BC (Canada)

1994-12-31

299

Three-year-olds’ memory for a person met only once at the age of 12 months: Very long-term memory revealed by a late-manifesting novelty preference  

DEFF Research Database (Denmark)

This study examined three-year-olds’ verbal and non-verbal memory for a person met only once after a 28 month interval. Children in the Test group (N=50) had participated in an earlier experiment at our lab at the age of 12 months where they met one of two possible experimenters. At this past event half of the children were tested by one, the other half by the other experimenter. At the follow-up, run by a naïve experimenter, the children were shown two videos from the original experiment in a visual paired comparison task: One with the specific experimenter testing them at the original visit (the Target) and one of the other experimenter (the Foil), with whom they had no experience. When explicitly asked, the children’s responses did not differ from chance. However, eye-tracking data revealed a late-manifesting novelty preference for the “Foil” person indicating memory for the “Target” person met once before.

Kingo, Osman Skjold; Staugaard, SØren RislØv

2014-01-01

300

Uranium ... long-term confidence  

International Nuclear Information System (INIS)

Half way through 1983 the outlook for the world's uranium producers was far from bright if one takes a short term view. The readily accessible facts present a gloomy picture. The spot prices of uranium over the past few years decreased from a high of $42-$43/lb to a low of $17 in 1982. It now hovers between $23 and $24. the contract prices negotiated between producers and consumers are not so accessible but they do not reflect the spot price. The reasons why contractual uranium prices do not follow the usual dictates of supply and demand are related to the position in which uranium and associated power industries find themselves. There is public reaction with strong emotional overtones as well as much reduced expectations about the electric power needs of the world. Furthermore the supply of uranium is not guaranteed despite present over production. However the people in the industry, taking the medium- and long-term view, are not despondent

301

Physiological, Molecular and Genetic Mechanisms of Long-Term Habituation  

Energy Technology Data Exchange (ETDEWEB)

Work funded on this grant has explored the mechanisms of long-term habituation, a ubiquitous form of learning that plays a key role in basic cognitive functioning. Specifically, behavioral, physiological, and molecular mechanisms of habituation have been explored using a simple model system, the tail-elicited siphon-withdrawal reflex (T-SWR) in the marine mollusk Aplysia californica. Substantial progress has been made on the first and third aims, providing some fundamental insights into the mechanisms by which memories are stored. We have characterized the physiological correlates of short- and long-term habituation. We found that short-term habituation is accompanied by a robust sensory adaptation, whereas long-term habituation is accompanied by alterations in sensory and interneuron synaptic efficacy. Thus, our data indicates memories can be shifted between different sites in a neural network as they are consolidated from short to long term. At the molecular level, we have accomplished microarray analysis comparing gene expression in both habituated and control ganglia. We have identified a network of putatively regulated transcripts that seems particularly targeted towards synaptic changes (e.g. SNAP25, calmodulin) . We are now beginning additional work to confirm regulation of these transcripts and build a more detailed understanding of the cascade of molecular events leading to the permanent storage of long-term memories. On the third aim, we have fostered a nascent neuroscience program via a variety of successful initiatives. We have funded over 11 undergraduate neuroscience scholars, several of whom have been recognized at national and regional levels for their research. We have also conducted a pioneering summer research program for community college students which is helping enhance access of underrepresented groups to life science careers. Despite minimal progress on the second aim, this project has provided a) novel insight into the network mechanisms by which short-term memories are permanently stored, and b) a strong foundation for continued growth of an excellent undergraduate neuroscience program.

Calin-Jageman, Robert J

2009-09-12

302

Differential Long-Term Effects of Haloperidol and Risperidone on the Acquisition and Performance of Tasks of Spatial Working and Short-Term Memory and Sustained Attention in Rats  

OpenAIRE

A common feature of the neuropsychiatric disorders for which antipsychotic drugs are prescribed is cognitive dysfunction, yet the effects of long-term antipsychotic treatment on cognition are largely unknown. In the current study, we evaluated the effects of long-term oral treatment with the first-generation antipsychotic haloperidol (1.0 and 2.0 mg/kg daily) and the second-generation antipsychotic risperidone (1.25 and 2.5 mg/kg daily) on the acquisition and performance of two radial-arm maz...

Hutchings, Elizabeth J.; Waller, Jennifer L.; Terry, Alvin V.

2013-01-01

303

Projecting Long-Term Primary Energy Consumption  

OpenAIRE

In this paper we use the long-term empirical relationship among primary energy consumption, real income, physical capital, population and technology, obtained by averaged panel error correction models, to project the long-term primary energy consumption of 56 countries up to 2100. In forecasting long-term primary energy consumption, we work with four different Shared Socioeconomic Pathway Scenarios (SSPs) developed for the Intergovernmental Panel on Climate Change (IPCC) framew...

Csereklyei, Zsuzsanna; Humer, Stefan

2013-01-01

304

Melatonin inhibits hippocampal long-term potentiation  

OpenAIRE

The goal of this study is to investigate the effect of the hormone melatonin on long-term potentiation and excitability measured by stimulating the Schaffer collaterals and recording the field excitatory postsynaptic potential from the CA1 dendritic layer in hippocampal brain slices from mice. Application of melatonin produced a concentration-dependent inhibition of the induction of long-term potentiation, with a concentration of 100 nM producing an ?50% inhibition of long-term potentiation...

Wang, Louisa M.; Suthana, Nanthia A.; Chaudhury, Dipesh; Weaver, David R.; Colwell, Christopher S.

2005-01-01

305

Long Term Outcomes after Pediatric Liver Transplantation  

OpenAIRE

Long term outcomes after liver transplantation are major determinants of quality of life and of the value of this heroic treatment. As short term outcomes are excellent, our community is turning to take a harder look at long term outcomes. The purpose of this paper is to review these outcomes, and highlight proposed treatments, as well as pressing topics needing to be studied. A systemic review of the English literature was carried in PubMed, covering all papers addressing long term outcomes ...

Yazigi, Nada A.

2013-01-01

306

Diversity in Long-Term Synaptic Plasticity at Inhibitory Synapses of Striatal Spiny Neurons  

Science.gov (United States)

Procedural memories and habits are posited to be stored in the basal ganglia, whose intrinsic circuitries possess important inhibitory connections arising from striatal spiny neurons. However, no information about long-term plasticity at these synapses is available. Therefore, this work describes a novel postsynaptically dependent long-term

Rueda-Orozco, Pavel E.; Mendoza, Ernesto; Hernandez, Ricardo; Aceves, Jose J.; Ibanez-Sandoval, Osvaldo; Galarraga, Elvira; Bargas, Jose

2009-01-01

307

SGK Protein Kinase Facilitates the Expression of Long-Term Potentiation in Hippocampal Neurons  

Science.gov (United States)

Previous studies showed that the serum- and glucocorticoid-inducible kinase ("sgk") gene plays an important role in long-term memory formation. The present study further examined the role of SGK in long-term potentiation (LTP). The dominant-negative mutant of "sgk," SGKS422A, was used to inactivate SGK. Results revealed a time-dependent increase…

Ma, Yun L.; Tsai, Ming C.; Hsu, Wei L.; Lee, Eminy H.Y.

2006-01-01

308

Methylphenidate amplifies long-term plasticity in the hippocampus via noradrenergic mechanisms.  

OpenAIRE

Methylphenidate treatment is used for Attention Deficit Hyperactivity Disorder and can improve learning and memory. Previously, improvements were considered a by-product of increased attention; however, we hypothesize that methylphenidate directly alters mechanisms underlying learning and memory, and therefore examined its effects on hippocampal long-term potentiation and long-term depression. Methylphenidate enhanced both mechanisms in the absence of presynaptic changes and in a noradrenalin...

Dommett, Ej; Henderson, El; Westwell, Ms; Greenfield, Sa

2008-01-01

309

Long term wet spent nuclear fuel storage  

International Nuclear Information System (INIS)

The meeting showed that there is continuing confidence in the use of wet storage for spent nuclear fuel and that long-term wet storage of fuel clad in zirconium alloys can be readily achieved. The importance of maintaining good water chemistry has been identified. The long-term wet storage behaviour of sensitized stainless steel clad fuel involves, as yet, some uncertainties. However, great reliance will be placed on long-term wet storage of spent fuel into the future. The following topics were treated to some extent: Oxidation of the external surface of fuel clad, rod consolidation, radiation protection, optimum methods of treating spent fuel storage water, physical radiation effects, and the behaviour of spent fuel assemblies of long-term wet storage conditions. A number of papers on national experience are included

310

Long term outcomes after pediatric liver transplantation.  

Science.gov (United States)

Long term outcomes after liver transplantation are major determinants of quality of life and of the value of this heroic treatment. As short term outcomes are excellent, our community is turning to take a harder look at long term outcomes. The purpose of this paper is to review these outcomes, and highlight proposed treatments, as well as pressing topics needing to be studied. A systemic review of the English literature was carried in PubMed, covering all papers addressing long term outcomes in pediatric liver transplant from 2000-2013. Late outcomes after pediatric liver transplant affect the liver graft in the form of chronic liver dysfunction. The causes include rejection particularly humoral rejection, but also de novo autoimmune hepatitis, and recurrent disease. The metabolic syndrome is a major factor in long term cardiovascular complication risk. Secondary infections, kidney dysfunction and malignancy remain a reality of those patients. There is growing evidence of late cognitive and executive function delays affecting daily life productivity as well as likely adherence. Finally, despite a good health status, quality of life measures are comparable to those of children with chronic diseases. Long term outcomes are the new frontier in pediatric liver transplantation. Much is needed to improve graft survival, but also to avoid systemic morbidities from long term immunosuppression. Quality of life is a new inclusive measure that will require interventions and innovative approaches respectful not only on the patients but also of their social circle. PMID:24511516

Yazigi, Nada A

2013-12-01

311

Long-term Synaptic Plasticity: Circuit Perturbation and Stabilization.  

Science.gov (United States)

At central synapses, activity-dependent synaptic plasticity has a crucial role in information processing, storage, learning, and memory under both physiological and pathological conditions. One widely accepted model of learning mechanism and information processing in the brain is Hebbian Plasticity: long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD are respectively activity-dependent enhancement and reduction in the efficacy of the synapses, which are rapid and synapse-specific processes. A number of recent studies have a strong focal point on the critical importance of another distinct form of synaptic plasticity, non-Hebbian plasticity. Non-Hebbian plasticity dynamically adjusts synaptic strength to maintain stability. This process may be very slow and occur cell-widely. By putting them all together, this mini review defines an important conceptual difference between Hebbian and non-Hebbian plasticity. PMID:25598658

Park, Joo Min; Jung, Sung-Cherl; Eun, Su-Yong

2014-12-01

312

Long-term follow-up study and long-term care of childhood cancer survivors  

Directory of Open Access Journals (Sweden)

Full Text Available The number of long-term survivors is increasing in the western countries due to remarkable improvements in the treatment of childhood cancer. The long-term complications of childhood cancer survivors in these countries were brought to light by the childhood cancer survivor studies. In Korea, the 5-year survival rate of childhood cancer patients is approaching 70%; therefore, it is extremely important to undertake similar long-term follow-up studies and comprehensive long-term care for our population. On the basis of the experiences of childhood cancer survivorship care of the western countries and the current Korean status of childhood cancer survivors, long-term follow-up study and long-term care systems need to be established in Korea in the near future. This system might contribute to the improvement of the quality of life of childhood cancer survivors through effective intervention strategies.

Hyeon Jin Park

2010-04-01

313

Collaboration of geldanamycin-activated P70S6K and Hsp70 against beta-amyloid-induced hippocampal apoptosis: an approach to long-term memory and learning.  

Science.gov (United States)

One of the neuropathological hallmarks of Alzheimer's disease (AD) is the accumulation of beta-amyloid peptides (A?) in senile plaques. A?-induced oxidative stress is believed to be responsible for degeneration and apoptosis of neurons and consequent cognitive and memory deficits. Here, we investigated the possible neuroprotective effect of the heat shock protein 90 (Hsp90) inhibitor geldanamycin (GA) against amyloid pathogenesis in adult male Wistar rats. GA or vehicle was injected into the lateral cerebral ventricles of rats 24 h before injection of A? (1-42) in CA1 area of hippocampus. The learning and memory of the rats were assessed 7 days after injection of A? using passive avoidance (PA) task. As potential contributing factors in A?-induced memory decline, we evaluated apoptotic markers and also used terminal-transferase UTP nick end labeling (TUNEL) technique to detect apoptosis in the hippocampus of A?-injected rats. Our behavioral data suggest that GA pretreatment can significantly suppress memory deficits in A?-injected rats. There was also not only a marked increase in Hsp70 level but also upregulated 70 kDa ribosomal protein S6 kinase (p70S6K) in the hippocampus of GA-treated groups with a reduction in apoptotic factors including caspase-3, poly (ADP-ribose) polymerase, Bax/Bcl-2 ratio, and TUNEL-positive cells as well. Thus, we conclude that GA exerts its protective effects against A? (1-42) toxicity and memory deficits, at least in part, by upregulating of Hsp70 and P70S6K. PMID:25576151

Zare, Nayereh; Motamedi, Fereshteh; Digaleh, Hadi; Khodagholi, Fariba; Maghsoudi, Nader

2015-03-01

314

Explaining long-term growth in Namibia  

Scientific Electronic Library Online (English)

Full Text Available Supply-side economics stresses the importance of analysing and modelling the long-term properties of an economy's production structures in order to investigate each factor of production's impact on final output. This helps to determine how much should be produced, how much is available for consumpti [...] on and, eventually, how an economy can improve its long-term economic growth path. This study applied the neoclassical growth model to Namibia's growth over the period from 1971 to 2005 in order to identify and develop the main supply-side components of long-term economic growth in the country. Along with a production function, behavioural equations were estimated for the factors of production labour demand and capital investment, as well as for the links between prices and wages.

Joel Hinaunye, Eita; Charlotte B, du Toit.

2009-04-01

315

Long-term outcomes after severe shock.  

Science.gov (United States)

Severe shock is a life-threatening condition with very high short-term mortality. Whether the long-term outcomes among survivors of severe shock are similar to long-term outcomes of other critical illness survivors is unknown. We therefore sought to assess long-term survival and functional outcomes among 90-day survivors of severe shock and determine whether clinical predictors were associated with outcomes. Seventy-six patients who were alive 90 days after severe shock (received ?1 ?g/kg per minute of norepinephrine equivalent) were eligible for the study. We measured 3-year survival and long-term functional outcomes using the Medical Outcomes Study 36-Item Short-Form Health Survey, the EuroQOL 5-D-3L, the Hospital Anxiety and Depression Scale, the Impact of Event Scale-Revised, and an employment instrument. We also assessed the relationship between in-hospital predictors and long-term outcomes. The mean long-term survival was 5.1 years; 82% (62 of 76) of patients survived, of whom 49 were eligible for follow-up. Patients who died were older than patients who survived. Thirty-six patients completed a telephone interview a mean of 5 years after hospital admission. The patients' Physical Functioning scores were below U.S. population norms (P < 0.001), whereas mental health scores were similar to population norms. Nineteen percent of the patients had symptoms of depression, 39% had symptoms of anxiety, and 8% had symptoms of posttraumatic stress disorder. Thirty-six percent were disabled, and 17% were working full-time. Early survivors of severe shock had a high 3-year survival rate. Patients' long-term physical and psychological outcomes were similar to those reported for cohorts of less severely ill intensive care unit survivors. Anxiety and depression were relatively common, but only a few patients had symptoms of posttraumatic stress disorder. This study supports the observation that acute illness severity does not determine long-term outcomes. Even extremely critically ill patients have similar outcomes to general intensive care unit survivor populations. PMID:25394248

Pratt, Cristina M; Hirshberg, Eliotte L; Jones, Jason P; Kuttler, Kathryn G; Lanspa, Michael J; Wilson, Emily L; Hopkins, Ramona O; Brown, Samuel M

2015-02-01

316

Short and long Term behavior of Knowledge  

OpenAIRE

This paper explores the behaviour of knowledge in the short and long term. Knowledge behaves very different in the short term than in the long term. Once we can measure knowledge it is then possible to look at its behaviour, an impossibility if there where no theory formulated to measure knowledge. Once we can measure, humans can attempt to put knowledge in formulae that make sense. This paper is a follow up to the previous papers, written by the same author. These papers being “The Fundame...

Khumalo, Bhekuzulu

2008-01-01

317

Strategic long term planning in mining  

Scientific Electronic Library Online (English)

Full Text Available The fundamental challenge facing mineral and metal companies is how to create sustainable value while operating within mandated strategic bounds, identified constraints, and variable market and economic conditions. This can be achieved by allowing the fixed physical nature of the mineral asset to dr [...] ive definition of the optimal technical solution to mining and processing activities, and developing and resourcing a strategically aligned portfolio of production entities that creates flexibility to near- and longer-term business environment shifts, i.e. a production mix that allows variation of output to respond to short term market variation, within a long term context. The practical achievement of this outcome is enabled by the concept of strategic long term planning. The core elements of strategic long term planning in the metals and minerals industry, and the relationship between them, are expanded. The strategic long term planning framework is a logic construct that enables delivery of an optimized, strategically-aligned business plan from the mineral asset portfolio using a set of tools and techniques with a common language, standards, systems and processes to align decisions and actions on a cyclical basis.

G.L., Smith.

318

Long-Term Care Ombudsman Program  

Science.gov (United States)

... for Coordination Related to Section Q Implementation Funding History Resources and Useful links Webinar: Medicaid Administrative Claiming and ... resource, AoA-funded National Long-Term Care Ombudsman Resource Center has developed a Fact Sheet on MDS 3.0 ... History Older Americans Act Title VII Chapter 2 (Ombudsman ...

319

Long-term projection: Initializing sea level  

Science.gov (United States)

Long-term climate change and sea-level rise in model projections have been primarily determined by external forcing of climate conditions. Now, research shows that centennial projections of the dynamic sea level are also sensitive to the ocean's initial conditions.

Yin, Jianjun

2015-04-01

320

JAXA's Long Term Vision in Science  

International Nuclear Information System (INIS)

Japan Aerospace Exploration Agency (JAXA) has been founded as a result of the integration of three space related institutions. JAXA's long term vision was defined in 2005 as the proposal on its initiative and provides the ideal situation of aerospace in the next 20 years. Space science is clearly defined as one of important categories in future

321

Eta Carinae long-term variability  

OpenAIRE

We present preliminary results of our analysis on the long-term variations observed in the optical spectrum of the LBV star Eta Carinae. Based on the hydrogen line profiles, we conclude that the physical parameters of the primary star did not change in the last 15 years.

Damineli, A.; Teodoro, M.; Corcoran, M.; Groh, J. H.

2010-01-01

322

Veterans Affairs Benefits (Long-Term Care)  

Science.gov (United States)

... Affairs to view available programs and services or download a Veterans Benefits fact sheet. You can call the VA at 800-827-1000 to obtain information about services available in your area. LTC PathFinder Long-term care is a big ...

323

Modeling long-term collider performance  

International Nuclear Information System (INIS)

A model for the SSC arcs is described with multipole lattice field errors agglomerated into 32 lattice points, and with first order lattice errors and modulation provided by discrete transfer elements. Numerical solutions for long term dynamic aperture studies are obtained by multipole kick-drift tracking. The CPU time required to track through one turn is minimal, and comparable to that required to implement a one-turn fifth-order Taylor series map. Comparisons with tracking results using a fine grained representation of the lattice are made, and found to be satisfactory. The effects of tune modulation are studied and can substantially degrade long-term dynamic aperture. The effects of small relativistic momentum corrections, usually neglected for the large momenta at the SSC, are shown to have negligible influence on tracking results. 5 refs., 7 figs

324

Analysis of long-term energy scenarios  

Energy Technology Data Exchange (ETDEWEB)

When addressing the role of fusion energy in the 21. century, the evaluation of possible future structures in the electricity market and the energy sector as a whole, can be a useful tool. Because fusion energy still needs demonstration, commercialized fusion energy is not likely to be a reality within the next few decades. Therefore long-term scenarios are needed describing the energy markets, which fusion energy eventually will be part of. This report performs an analysis of two of the most detailed existing long-term scenarios describing possible futures of the energy system. The aim is to clarify the frames in which the future development of the global energy demand, as well as the structure of the energy system can be expected to develop towards the year 2100. (au) 19 refs.

Lemming, J.; Morthorst, P.E.

1998-09-01

325

INTELLIGENT SYSTEM FOR LONG TERM LOAD FORECASTING  

Directory of Open Access Journals (Sweden)

Full Text Available Long term load forecasting plays an important role in the economic optimization and secured operation of electric power systems. The plans of the electric power sector have been done and developed with the aid of statistical prediction methods. Electric utilities companies need monthly peak and yearly load forecasting for budget planning, maintenance scheduling and fuel management. The present work presents a comparative study between the approach based on neural network and a hybrid fuzzy neural technique for long term load forecasting of Haryana State. A large number of influencing factors have been examined and tested. This paper presents a system developed for the prediction of maximum electric demand and consumption of electricity. The strength of this technique lies in its ability to reduce appreciable computational time and its comparable accuracy with other modeling techniques.

Roohi Kapoor

2011-01-01

326

Dynamics of long-term genomic selection  

OpenAIRE

Abstract Background Simulation and empirical studies of genomic selection (GS) show accuracies sufficient to generate rapid gains in early selection cycles. Beyond those cycles, allele frequency changes, recombination, and inbreeding make analytical prediction of gain impossible. The impacts of GS on long-term gain should be studied prior to its implementation. Methods A simulation case-study of this issue was done for barley, an inbred crop. On the basis of marker data on 192 breeding lines ...

Jannink Jean-Luc

2010-01-01

327

Managing soils for long-term productivity  

OpenAIRE

Meeting the goal of long-term agricultural productivity requires that soil degradation be halted and reversed. Soil fertility decline is a key factor in soil degradation and is probably the major cause of declining crop yields. There is evidence that the contribution of declining soil fertility to soil degradation has been underestimated. Sensitivity to soil degradation is implicit in the assessment of the sustainability of land management practices, with wide recognition of the fact that soi...

Syers, J. K.

1997-01-01

328

Long-term use of potassium perchlorate.  

OpenAIRE

A case of Graves' disease with potassium perchorate for 22 years without ill effect is described. Thyrotoxicosis recurred 4 weeks after the medication was withdrawn, suggesting that euthyroidism had been maintained by chronic use of the drug. As toxicity of perchlorate is probably dose related, it is suggested that long-term use of low dose perchlorate may be no more hazardous than alternative antithyroid therapy.

Connell, J. M.

1981-01-01

329

Work requirements and long term poverty  

OpenAIRE

We study how work requirements can be used to target transfers to the long term poor. Without commitment, time consistency requires all screening measures to be concentrated in the first phase of the program. We show that this increases the effectiveness of workfare; it is optimal to use work requirements for a wider range of prior beliefs about the size of the poor population, and work requirements are used more intensively. We compare these results with the optimal policy under commitment.

Schroyen, Fred; Torsvik, Gaute

1999-01-01

330

Long-term consequences of anorexia nervosa.  

Science.gov (United States)

Anorexia nervosa (AN) is a psychiatric disorder that occurs mainly in female adolescents and young women. The obsessive fear of weight gain, critically limited food intake and neuroendocrine aberrations characteristic of AN have both short- and long-term consequences for the reproductive, cardiovascular, gastrointestinal and skeletal systems. Neuroendocrine changes include impairment of gonadotropin releasing-hormone (GnRH) pulsatile secretion and changes in neuropeptide activity at the hypothalamic level, which cause profound hypoestrogenism. AN is related to a decrease in bone mass density, which can lead to osteopenia and osteoporosis and a significant increase in fracture risk in later life. Rates of birth complications and low birth weight may be higher in women with previous AN. The condition is associated with fertility problems, unplanned pregnancies and generally negative attitudes to pregnancy. During pregnancy, women with the condition have higher rates of hyperemesis gravidarum, anaemia and obstetric complications, as well as impaired weight gain and compromised intrauterine foetal growth. It is reported that 80% of AN patients are affected by a cardiac complications such as sinus bradycardia, a prolonged QT interval on electrocardiography, arrythmias, myocardial mass modification and hypotension. A decrease in bone mineral density (BMD) is one of the most important medical consequences of AN. Reduced BMD may subsequently lead to a three- to seven-fold increased risk of spontaneous fractures. Untreated AN is associated with a significant increase in the risk of death. Better detection and sophisticated therapy should prevent the long-term consequences of this disorder. The aims of treatment are not only recovery but also prophylaxis and relief of the long-term effects of this disorder. Further investigations of the long-term disease risk are needed. PMID:23706279

Meczekalski, Blazej; Podfigurna-Stopa, Agnieszka; Katulski, Krzysztof

2013-07-01

331

Long-term Treatment in Multiple Sclerosis  

Directory of Open Access Journals (Sweden)

Full Text Available Multiple sclerosis is a chronic neuro-inflammatory and neuro-degenerative disease of the CNS which may present and progress heterogeneously. It is rather a spectrum and currently there is some evidence that long term treatments may be effective for its relapsing forms. Such treatments have been shown to reduce the number of attacks and MRI-related disease burden with the probability to slow progression. These long term treatments are considered to have mostly an anti-inflammatory activity. Interferon beta group drugs and glatiramer acetate are likely to exert their therapeutic effects through a number of different mechanisms but probably the main one is anti-inflammatory being through such mechanisms, but their efficacy is limited. Immunosuppressive drugs such as Mitoxantrone and Cyclophosphamide are accepted to have a more potent anti-inflammatory effect with better efficacy, but with more serious adverse effects. Natalizumab is one of the new players in the field with a supposedly better efficacy than the interferon betas or glatiramer acetate, but yet carries an increased risk of being associated with progressive mulifocal leukoencepalopathy as a serious side effect. As not all patients with MS progress and end up with disability, long-term treatments may not be necessary for every individual, who receives the diagnosis of MS. It is the MS neurologist who should consider first whether the patient should be put on long term treatment and once such a decision is given, then which one. The agents to be selected should be determined according to the benefit-risk ratio for each patient individually. In this review these issues are discussed. (Archives of Neuropsychiatry 2008; 45 Supplement: 26-36

Derya ULUDÜZ

2008-05-01

332

Long-term trends in international production  

OpenAIRE

This paper describes long-term trends in international production, i.e. the production of goods and services that is under the governance of transnational corporations - either through foreign direct investment (FDI) or non-equity arrangements. It recounts the rapid growth in international production, the increasing importance of non-equity arrangements, and the shift towards services. The paper then examines the geography of FDI, emphasising that EU countries have emerged as a major source a...

Zimny, Zbigniew

2004-01-01

333

SLEEP DISTURBANCES IN LONG-TERM CARE  

OpenAIRE

Nighttime sleep disruption is characteristic of long-term care residents, is typically accompanied by daytime sleepiness and may be caused by a multitude of factors. Causal factors include medical and psychiatric illness, medications, circadian rhythm abnormalities, sleep disordered breathing and other primary sleep disorders, environmental factors and lifestyle habits. There is some suggestion that these factors are amenable to treatment; however, further research on the implementation of tr...

Martin, Jennifer L.; Ancoli-israel, Sonia

2008-01-01

334

Long-Term Monitoring of Photovoltaic Plants  

OpenAIRE

This paper deals with a data-acquisition system that has been specifically developed for a long-term monitoring of ten different photovoltaic plants. The main goals of the system consist in estimating the drift of the plant components, mainly photovoltaic modules and power inverters, and comparing the performance of the ten plants, which are based on different technologies and architectures. Owing to these goals, the traceabilityassurance of the obtained measurements is mandatory, hence the d...

Ferraris, Franco; Carullo, Alessio; Vallan, Alberto; Spertino, Filippo

2013-01-01

335

A long-term view of hypospadias.  

Science.gov (United States)

The long-term psychological and physical sequelae of hypospadias and its management were assessed in a study of 213 patients over the age of fifteen. A high level of adult dissatisfaction regarding the quality of their repairs both in terms of function and aesthetics, plus criticism of inadequate guidance, indicates the need for follow-up until at least mid-teens, and the choice of operations which produce a terminal meatus and more natural appearance. PMID:2758195

Bracka, A

1989-05-01

336

Long-term course of opioid addiction.  

Science.gov (United States)

Opioid addiction is associated with excess mortality, morbidities, and other adverse conditions. Guided by a life-course framework, we review the literature on the long-term course of opioid addiction in terms of use trajectories, transitions, and turning points, as well as other factors that facilitate recovery from addiction. Most long-term follow-up studies are based on heroin addicts recruited from treatment settings (mostly methadone maintenance treatment), many of whom are referred by the criminal justice system. Cumulative evidence indicates that opioid addiction is a chronic disorder with frequent relapses. Longer treatment retention is associated with a greater likelihood of abstinence, whereas incarceration is negatively related to subsequent abstinence. Over the long term, the mortality rate of opioid addicts (overdose being the most common cause) is about 6 to 20 times greater than that of the general population; among those who remain alive, the prevalence of stable abstinence from opioid use is low (less than 30% after 10-30 years of observation), and many continue to use alcohol and other drugs after ceasing to use opioids. Histories of sexual or physical abuse and comorbid mental disorders are associated with the persistence of opioid use, whereas family and social support, as well as employment, facilitates recovery. Maintaining opioid abstinence for at least five years substantially increases the likelihood of future stable abstinence. Recent advances in pharmacological treatment options (buprenorphine and naltrexone) include depot formulations offering longer duration of medication; their impact on the long-term course of opioid addiction remains to be assessed. PMID:25747921

Hser, Yih-Ing; Evans, Elizabeth; Grella, Christine; Ling, Walter; Anglin, Douglas

2015-01-01

337

Long term results of pneumatic retinopexy  

OpenAIRE

Amin F EllakwaMenoufiya University, Shibin el Kom, Al-Menoufiya, EgyptBackground: Rhegmatogenous retinal detachment is a commonly encountered retinal problem where rapid treatment can prevent irreversible vision loss. Pneumatic retinopexy (PR) is a simple, minimally invasive procedure for retinal reattachment.Purpose: This study aimed to assess the long-term anatomical and functional outcome of pneumatic retinopexy in primary rhegmatogenous retinal detachment.Patients and methods: A prospecti...

Af, Ellakwa

2012-01-01

338

Model of long-term seismogenesis  

OpenAIRE

A three-stage faulting model explains the observed quantitative relations between long-term precursory seismicity, mainshocks and aftershocks. Seismogenesis starts with the formation of a major crack, culminates in the corresponding major fracture and earthquake, and ends with healing. Crack formation is a self-organised critical phenomenon, and shear fracture is a delayed sequel to crack formation. It is postulated that the major crack generates a set of minor cracks, just as, later, the maj...

Rhoades, D.; Evison, F.

2001-01-01

339

Titanium for long-term tritium storage  

International Nuclear Information System (INIS)

Due to the reduction of nuclear weapon stockpile, there will be an excess of tritium returned from the field. The excess tritium needs to be stored for future use, which might be several years away. A safe and cost effective means for long term storage of tritium is needed. Storing tritium in a solid metal tritide is preferred to storing tritium as a gas, because a metal tritide can store tritium in a compact form and the stored tritium will not be released until heat is applied to increase its temperature to several hundred degrees centigrade. Storing tritium as a tritide is safer and more cost effective than as a gas. Several candidate metal hydride materials have been evaluated for long term tritium storage. They include uranium, La-Ni-Al alloys, zirconium and titanium. The criteria used include material cost, radioactivity, stability to air, storage capacity, storage pressure, loading and unloading conditions, and helium retention. Titanium has the best combination of properties and is recommended for long term tritium storage

340

Electrodes for long-term esophageal electrocardiography.  

Science.gov (United States)

The emerging application of long-term and high-quality ECG recording requires alternative electrodes to improve the signal quality and recording capability of surface skin electrodes. The esophageal ECG has the potential to overcome these limitations but necessitates novel recorder and lead designs. The electrode material is of particular interest, since the material has to ensure conflicting requirements like excellent biopotential recording properties and inertness. To this end, novel electrode materials like PEDOT and silver-PDMS as well as established electrode materials such as stainless steel, platinum, gold, iridium oxide, titanium nitride, and glassy carbon were investigated by long-term electrochemical impedance spectroscopy and model-based signal analysis using the derived in vitro interfacial properties in conjunction with a dedicated ECG amplifier. The results of this novel approach show that titanium nitride and iridium oxide featuring microstructured surfaces did not degrade when exposed to artificial acidic saliva. These materials provide low electrode potential drifts and insignificant signal distortion superior to surface skin electrodes making them compatible with accepted standards for ambulatory ECG. They are superior to the noble and polarizable metals such as platinum, silver, and gold that induced more signal distortions and are superior to esophageal stainless steel electrodes that corrode in artificial saliva. The study provides rigorous criteria for the selection of electrode materials for prolonged ECG recording by combining long-term in vitro electrode material properties with ECG signal quality assessment. PMID:23649132

Niederhauser, Thomas; Haeberlin, Andreas; Marisa, Thanks; Jungo, Michael; Goette, Josef; Jacomet, Marcel; Abacherli, Roger; Vogel, Rolf

2013-09-01

341

Long-term EEG in children.  

Science.gov (United States)

Long-term video-EEG corresponds to a recording ranging from 1 to 24h or even longer. It is indicated in the following situations: diagnosis of epileptic syndromes or unclassified epilepsy, pre-surgical evaluation for drug-resistant epilepsy, follow-up of epilepsy or in cases of paroxysmal symptoms whose etiology remains uncertain. There are some specificities related to paediatric care: a dedicated pediatric unit; continuous monitoring covering at least a full 24-hour period, especially in the context of pre-surgical evaluation; the requirement of presence by the parents, technician or nurse; and stronger attachment of electrodes (cup electrodes), the number of which is adapted to the age of the child. The chosen duration of the monitoring also depends on the frequency of seizures or paroxysmal events. The polygraphy must be adapted to the type and topography of movements. It is essential to have at least an electrocardiography (ECG) channel, respiratory sensor and electromyography (EMG) on both deltoids. There is no age limit for performing long-term video-EEG even in newborns and infants; nevertheless because of scalp fragility, strict surveillance of the baby's skin condition is required. In the specific context of pre-surgical evaluation, long-term video-EEG must record all types of seizures observed in the child. This monitoring is essential in order to develop hypotheses regarding the seizure onset zone, based on electroclinical correlations, which should be adapted to the child's age and the psychomotor development. PMID:25687590

Montavont, A; Kaminska, A; Soufflet, C; Taussig, D

2015-03-01

342

Establishment of a cohort for the long-term clinical follow-up with dose reconstruction under the joint medical research project conducted by Sasakawa Memorial Health Foundation (Japan) and the Research Institute of Radiation Hygiene (Russia)  

International Nuclear Information System (INIS)

The cohort of children in the western districts of the Bryansk Region of Russia exposed to radiation following the Chernobyl accident is described in this paper. The cohort was selected under the Joint Medical Research Project on Dosimetry Associated with the Chernobyl Accident conducted by Sasakawa Memorial Health Foundation (SMHF, Japan) and the Research Institute of Radiation Hygiene (RIRH, Russia). The subjects of the Research Project are those people residing in the most contaminated areas of Russia who was 0 to 10 years old at the time of exposure. At the moment the cohort comprises 1210 subjects, though this number may slightly decrease in course of a follow-up in view of migration of population. Most of cohort subjects were examined on their health status within the framework of the Chernobyl Sasakawa Health and Medical Cooperation Project (CSHMCP) from 1991-1996. In view of the main findings of studies in CSHMCP were thyroid abnormalities, selection of subjects was conducted on the basis of the credible estimates of thyroid dose. Preference for subjects to be included into the cohort was defined by the availability of health examination data from previous study (1991-1996) and individual dosimetry, environmental and social data that may prove useful for reconstruction of individual dose. The primary data analyzed for subjects selection are measurements of iodine-131 in the thyroid in May-June 1986, questionnaire data on individual food habits and early measuron individual food habits and early measurements of radiocesium in the body of subjects made by RIRH from May to September 1986. Plausible analytical models were applied to calculate thyroid dose from available data. Previously worked out methods of thyroid dose reconstruction using early measurement data of radiocesium content in the body and questionnaire data on individual consumption of locally produced milk were reevaluated. Basing on these analytical procedures, the individual thyroid dose was ascribed to each member of the cohort. The preliminary distribution of internal radiation doses to the thyroid among subjects of the cohort is presented in the paper. The summary characteristics of dose distribution for cohort subjects seems to be reasonably credible, whereas, the individual doses to particular subjects are evaluated with essential degree of uncertainty. The further stage of dose reconstruction for a cohort study, that is now in progress, consists of reduction of these uncertainties by using additional (newly derived) questionnaire information, as well as by taking into account contribution of external radiation to thyroid dose and updating analytical procedures to interpret primary data. Finally, the distribution of subjects into several thyroid dose ranges, from 2 Gy, would be an acceptable approximation for the purposes of radiation epidemiology in a trial to access the radiation risk of developing thyroid diseases. (author)

343

Simulations suggest pharmacological methods for rescuing long-term potentiation.  

Science.gov (United States)

Congenital cognitive dysfunctions are frequently due to deficits in molecular pathways that underlie the induction or maintenance of synaptic plasticity. For example, Rubinstein-Taybi syndrome (RTS) is due to a mutation in cbp, encoding the histone acetyltransferase CREB-binding protein (CBP). CBP is a transcriptional co-activator for CREB, and induction of CREB-dependent transcription plays a key role in long-term memory (LTM). In animal models of RTS, mutations of cbp impair LTM and late-phase long-term potentiation (LTP). As a step toward exploring plausible intervention strategies to rescue the deficits in LTP, we extended our previous model of LTP induction to describe histone acetylation and simulated LTP impairment due to cbp mutation. Plausible drug effects were simulated by model parameter changes, and many increased LTP. However no parameter variation consistent with a effect of a known drug class fully restored LTP. Thus we examined paired parameter variations consistent with effects of known drugs. A pair that simulated the effects of a phosphodiesterase inhibitor (slowing cAMP degradation) concurrent with a deacetylase inhibitor (prolonging histone acetylation) restored normal LTP. Importantly these paired parameter changes did not alter basal synaptic weight. A pair that simulated the effects of a phosphodiesterase inhibitor and an acetyltransferase activator was similarly effective. For both pairs strong additive synergism was present. The effect of the combination was greater than the summed effect of the separate parameter changes. These results suggest that promoting histone acetylation while simultaneously slowing the degradation of cAMP may constitute a promising strategy for restoring deficits in LTP that may be associated with learning deficits in RTS. More generally these results illustrate how the strategy of combining modeling and empirical studies may provide insights into the design of effective therapies for improving long-term synaptic plasticity and learning associated with cognitive disorders. PMID:25034337

Smolen, Paul; Baxter, Douglas A; Byrne, John H

2014-11-01

344

Memory Networks  

OpenAIRE

We describe a new class of learning models called memory networks. Memory networks reason with inference components combined with a long-term memory component; they learn how to use these jointly. The long-term memory can be read and written to, with the goal of using it for prediction. We investigate these models in the context of question answering (QA) where the long-term memory effectively acts as a (dynamic) knowledge base, and the output is a textual response. We evalu...

Weston, Jason; Chopra, Sumit; Bordes, Antoine

2014-01-01

345

Long-term outcomes of infantile spasms  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose : The aims of this study were to investigate the long-term outcomes in children with infantile spasms (IS and to identify the prognostic factors influencing their neurodevelopment. Methods : We retrospectively evaluated seventy two children over five years old who were treated for IS at Asan Medical Center, Seoul, Korea, between 1994 and 2007. Forty-three children were contacted by telephone or medical follow-up to assess their current neurodevelopmental status. Multiple logistic regression was used to calculate odds ratios (ORs and 95% confidence interval (95% CIs of risk factors for unfavorable outcomes. Results : The mean follow-up duration for these 43 children was 7.2¡?#?.5 ;years (range, 4.5 to 13.0 years. Of these, 13 (30.2% had cryptogenic and 30 (69.8% had symptomatic IS. Eleven (25.6% children were initially treated with adrenocorticotrophic hormone (ACTH therapy, with a mean treatment lag of 1.3¡?#?.9 ;months (range; 0.1 to 7.0 months. Eighteen (41.8% children clinically responded to initial treatment, as shown by EEG response. Overall, 22 (51.2% children had at least moderate neurodevelopmental disorders and 2 (4.8% died. In univariate analysis, etiology (symptomatic and poor electroclinical response to initial treatment were related to long-term unfavorable outcomes. In multivariate analysis, response to primary treatment was the sole significant independent risk factor with a high OR. Conclusion : Overall prognosis of children with IS was poor. Electroclinical non-responsiveness to initial treatment was related to unfavorable long-term outcomes, indicating that initial control of seizures may be important in reducing the likelihood of poor neurodevelopment.

Seak Hee Oh

2010-01-01

346

Long term uranium supply for KEPCO  

International Nuclear Information System (INIS)

The industrial development of the Republic of Korea lead to strong growth in energy demand. To decrease the dependence on imported oil supplies, the Korea Electric Power Corporation (KEPCO) invested in nuclear power plants, thermal power plants fired with coal and LNG as well as hydroelectric plants. Subsequently, the electrical, generating capacity by coal-fired power plants, has decreased from 72% in 1975 to 24% in 1988. In the same year, the share of the nuclear generating capacity reached 33.4%. The nuclear power programme in the Republic of Korea started in 1978, when the first nuclear power plant, KORI Unit 1, a 587 MW(e)-PWR went into commercial operation. In April 1989, there were a total of eight nuclear power plants with a continued capacity of 6666 MW(e) in operation. One additional plant with 550 MW(e) capacity is nearing completion. Two further NPP are in earlier stages of construction. It is planned that by 1996, these two reactors will be completed and that the total nuclear electricity generating capacity will reach 9616 MW(e) supplying about 47% of the total electricity of the country. Through the end of the century two more NPP with 1000 MW(e) are planned. The uranium requirements for the nuclear programme of the Republic of Korea will increase from over 1200 t U in 1989 to about 2150 t in 2005. As there are no indigenous mineable uranium resources in the country, supplies have to be secured from outside sources, both through short and long term purcces, both through short and long term purchase contracts and through investments in uranium projects. At present, about 50% of the requirements through 2000 are covered by long term contracts, while the remainder is planned to be secured from production centres at which KEPCO holds equities as in Dawn Lake, Cigar Lane and Crow Butte, and through spot market purchases. (author). 5 tabs

347

Long-term economic development problems  

International Nuclear Information System (INIS)

The long-term economic development of New Mexico parallels the major energy issue of the nation - the impact of non-proliferation policy. The short lifespan and waste of energy resources in this country reflects a lack of foresight which can no longer be tolerated. The principal unknowns affecting uranium development in New Mexico are the extent and demand for uranium, the nuclear fuel cycle, and the lifespan of nuclear power plants, with or without reprocessing. Further areas of concern include the costs of reprocessing facilities, the evaluation of fuel cycles to minimize proliferation, and the impacts of waste disposal

348

Osteoarthropathy in long-term hemodialysis patients  

International Nuclear Information System (INIS)

The authors reviewed hand and wrist films of 81 patients who had undergone hemodialysis for a minimum of 5 and a mean duration 7.5 years. The films of 32 patients showed arthritic changes consisting of articular erosions, joint space narrowings, periarticular cysts, and osteopenia. Five of these patients had subcutaneous or periarticular calcific deposits. The frequency and severity of the radiographic findings increased with increasing duration of dialysis. It appears that in addition to the well-recognized secondary hyperparathyroidism there is a second commonly occurring osteoarthropathy (40% in this series) related to long-term hemodialysis

349

Natural analogs. Long-term system analysis  

International Nuclear Information System (INIS)

The natural analogs are systems evolving with freedom within the nature during very large periods of time (geological periods) and because of their lithological, structural, geochemical and hydrogeological context present a big similitude with the total or partial performance of some systems suggested as geological deep storage sites for high level radioactive wastes. The knowledge and study of such systems shed light into the performance of waste deposits at long-term scenarios. The different studies about analogs in Canada (Cigar lake) Gabon (Oko), Spain (Berrocal), Finland (Palmottu) are analyzed

350

Long-Term Wind Power Variability  

Energy Technology Data Exchange (ETDEWEB)

The National Renewable Energy Laboratory started collecting wind power data from large commercial wind power plants (WPPs) in southwest Minnesota with dedicated dataloggers and communication links in the spring of 2000. Over the years, additional WPPs in other areas were added to and removed from the data collection effort. The longest data stream of actual wind plant output is more than 10 years. The resulting data have been used to analyze wind power fluctuations, frequency distribution of changes, the effects of spatial diversity, and wind power ancillary services. This report uses the multi-year wind power data to examine long-term wind power variability.

Wan, Y. H.

2012-01-01

351

Long-term clinical outcome in patients with pineal germinoma  

International Nuclear Information System (INIS)

We retrospectively analyzed the long-term clinical course of 10 patients with pineal germinomas to determine the best treatment modality for achieving a good outcome. Subjects were treated at the Gunma University Hospital between 1980 and 1998, given a total dose of 40-50 Gy (mean: 49 Gy) delivered under a conventional fractionation schedule. Tumors had shrunk at 20 Gy in all 10 patients. Mean follow-up was 13.5 years (162 months, range, 59 to 268 months). Five-year survival for the group was 100%. None experienced intracranial disease recurrence. No new abnormalities in internal secretion considered to be due to radiotherapy were seen. Karnofsky performance scales (KPS) for 8 of the 10 were 100. KPS of the remaining 2 were 80, including easy fatiguability, mild ataxia, and recent memory disturbance. Administration of doses of 50 Gy for pineal germinoma is adequate for controlling the tumor over the long term but may reduce the patientis quality of life. Further study is therefore needed to determine the optimal dosage for pineal germinoma. (author)

352

The long term radioactive storage alternative  

International Nuclear Information System (INIS)

With uncertainty regarding the Yucca Mountain geologic repository being just one manifestation of the controversy over where, how, and whether radioactive waste can be safely treated and disposed in a publicly acceptable manner, the authors suggest that a new approach regarding the storage of spent nuclear fuel (SNF) and radioactive waste is needed and, fortunately, available. Safely storing wastes in an environmentally-acceptable, monitored manner while a national political and technical consensus is reached on how to properly treat it prior to its ultimate disposal may be the most cost-effective and rational method of addressing these issues in the interim. Because of the limitations imposed on treatment and disposal options by state governments, legislative and regulatory requirements, and legal challenges, spent fuel, other reactor irradiated nuclear material (RINM), and radioactive waste are remaining where they were produced, usually in facilities neither sited nor designed with long-term storage in mind. The inertia associated with difficult choices based on imperfect information has resulted in a decision-making gridlock where an unpopular status quo continues and promising solutions remain untried. However, well-planned and locally accepted centralization of wastes (especially medical) within states and/or acceptance of dry spent fuel storage at each nuclear generating station can break the current gridlock of disposal and storage actions and inactions and cal and storage actions and inactions and can result in a more desirable outcome both in the intermediate and long term

353

Long-term environmental behaviour of radionuclides  

Energy Technology Data Exchange (ETDEWEB)

The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: (i) redistribution in the soil-plant system, (ii) modelling, (iii) countermeasures, (iv) runoff (v) spatial variations, and (vi) dose assessment. The long term behaviour of the radionuclides {sup 137}Cs, {sup 90}Sr and {sup 239-240}Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

Brechignac, F.; Moberg, L.; Suomela, M

2000-04-01

354

Long term testing of PSI-membranes  

Energy Technology Data Exchange (ETDEWEB)

Long term tests of PSI membranes based on radiation-grafted FEP and ETFE films were carried out and FEP-based membranes were evaluated by monitoring the in-situ membrane area resistance measured by a current pulse method. By modifying our irradiation procedure and using the double crosslinking concept we obtain reproducible membrane cell lifetimes (in term of in-situ membrane resistance) of greater than 5000 hours at 60-65{sup o}C. Preliminary tests at 80-85{sup o}C with lifetimes of greater than 2500 demonstrate the potential long term stability of PSI proton exchange membranes based on FEP over the whole operating temperature range of low-temperature polymer electrolyte fuel cells. Radiation grafted PSI membranes based on ETFE have better mechanical properties than those of the FEP membranes. Mechanical properties are particularly important in large area cells and fuel cell stacks. ETFE membranes have been tested successfully for approximately 1000 h in a 2-cell stack (100 cm{sup 2} active area each cell). (author) 4 figs., 4 refs.

Huslage, J.; Brack, H.P.; Geiger, F.; Buechi, F.N.; Tsukada, A.; Scherer, G.G. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

1999-08-01

355

Long-term environmental behaviour of radionuclides  

International Nuclear Information System (INIS)

The radioactive pollution of the environment results from the atmospheric nuclear weapons testing (during the mid-years of twentieth century), from the development of the civilian nuclear industry and from accidents such as Chernobyl. Assessing the resulting radiation that humans might receive requires a good understanding of the long-term behaviour of radionuclides in the environment. This document reports on a joint European effort to advance this understanding, 3 multinational projects have been coordinated: PEACE, EPORA and LANDSCAPE. This report proposes an overview of the results obtained and they are presented in 6 different themes: i) redistribution in the soil-plant system, ii) modelling, iii) countermeasures, iv) runoff v) spatial variations, and vi) dose assessment. The long term behaviour of the radionuclides 137Cs, 90Sr and 239-240Pu is studied through various approaches, these approaches range from in-situ experiments designed to exploit past contamination events to laboratory simulations. A broad scope of different ecosystems ranging from arctic and boreal regions down to mediterranean ones has been considered. (A.C.)

356

Institutionalization and organizational long-term success  

Scientific Electronic Library Online (English)

Full Text Available Institutionalization processes have an ambivalent effect on organizational long-term success. Even though they foster organizational stability and permanence, they also bring about rigidity and resistance to change. As a result, successful organizations are likely to lose their competitive advantage [...] over time. The paper addresses this issue through the investigation of the institutionalization processes of two long-lived companies: General Electric, a firm that has been a long-term success and its rival, Westinghouse, which was broken up after eleven decades of existence. The longitudinal, multilevel analysis of firms and industry has identified two different modes of organizational institutionalization. The reactive mode gives rise to rigidity and change resistance, much like institutional theory predicts; the proactive mode, on the other hand, neutralizes those negative effects of institutionalization processes. In the reactive mode, structure predominates. In the proactive mode, agency plays a major role in organizational institutionalization, and in managing the organization's relations with the environment, clearly contributing to environmental institutionalization.

Denise, Fleck.

2007-08-01

357

Long-Term Potentiation in the Motor Cortex  

Science.gov (United States)

Long-term potentiation (LTP) is a model for learning and memory processes. Tetanic stimulation of the sensory cortex produces LTP in motor cortical neurons, whereas tetanization of the ventrolateral nucleus of the thalamus, which also projects to the motor cortex, does not. However, after simultaneous high-frequency stimulation of both the sensory cortex and the ventrolateral nucleus of the thalamus, LTP of thalamic input to motor cortical neurons is induced. This associative LTP occurs only in neurons in the superficial layers of the motor cortex that receive monosynaptic input from both the sensory cortex and the ventrolateral nucleus of the thalamus. Associative LTP in the motor cortex may constitute a basis for the retention of motor skills.

Iriki, Atsushi; Pavlides, Constantine; Keller, Asaf; Asanuma, Hiroshi

1989-09-01

358

States of curiosity modulate hippocampus-dependent learning via the dopaminergic circuit.  

Science.gov (United States)

People find it easier to learn about topics that interest them, but little is known about the mechanisms by which intrinsic motivational states affect learning. We used functional magnetic resonance imaging to investigate how curiosity (intrinsic motivation to learn) influences memory. In both immediate and one-day-delayed memory tests, participants showed improved memory for information that they were curious about and for incidental material learned during states of high curiosity. Functional magnetic resonance imaging results revealed that activity in the midbrain and the nucleus accumbens was enhanced during states of high curiosity. Importantly, individual variability in curiosity-driven memory benefits for incidental material was supported by anticipatory activity in the midbrain and hippocampus and by functional connectivity between these regions. These findings suggest a link between the mechanisms supporting extrinsic reward motivation and intrinsic curiosity and highlight the importance of stimulating curiosity to create more effective learning experiences. PMID:25284006

Gruber, Matthias J; Gelman, Bernard D; Ranganath, Charan

2014-10-22

359

Effects of Spaced Repetition on Long-Term Map Knowledge Recall  

Science.gov (United States)

Sixth-grade students studying Latin America were placed in experimental and comparison groups to test the effects of map-study repetition on long-term memory. Mean scores on place-name repetition indicated that the experimental (repetition) group out-performed the comparison group at a statistically significant level with respect to both posttest…

Zirkle, David M.; Ellis, Arthur K.

2010-01-01

360

Nucleolar Integrity Is Required for the Maintenance of Long-Term Synaptic Plasticity  

OpenAIRE

Long-term memory (LTM) formation requires new protein synthesis and new gene expression. Based on our work in Aplysia, we hypothesized that the rRNA genes, stimulation-dependent targets of the enzyme Poly(ADP-ribose) polymerase-1 (PARP-1), are primary effectors of the activity-dependent changes in synaptic function that maintain synaptic plasticity and memory. Using electrophysiology, immunohistochemistry, pharmacology and molecular biology techniques, we show here, for the first time, that t...

Allen, Kim D.; Gourov, Andrei V.; Harte, Christopher; Gao, Peng; Lee, Clarice; Sylvain, Darlene; Splett, Joshua M.; Oxberry, William C.; Nes, Paula S.; Troy-regier, Matthew J.; Wolk, Jason; Alarcon, Juan M.; Herna?ndez, A. Iva?n

2014-01-01

361

Antagonism of lateral amygdala alpha1-adrenergic receptors facilitates fear conditioning and long-term potentiation  

OpenAIRE

Norepinephrine receptors have been studied in emotion, memory, and attention. However, the role of alpha1-adrenergic receptors in fear conditioning, a major model of emotional learning, is poorly understood. We examined the effect of terazosin, an alpha1-adrenergic receptor antagonist, on cued fear conditioning. Systemic or intra-lateral amygdala terazosin delivered before conditioning enhanced short- and long-term memory. Terazosin delivered after conditioning did not affect consolidation. I...

Lazzaro, Stephanie C.; Hou, Mian; Cunha, Catarina; Ledoux, Joseph E.; Cain, Christopher K.

2010-01-01

362

Opposing actions of chronic ?9-tetrahydrocannabinol and cannabinoid antagonists on hippocampal long-term potentiation  

OpenAIRE

Memory deficits produced by marijuana arise partly via interaction of the psychoactive component, ?9-tetrahydrocannabinol (?9-THC), with cannabinoid receptors in the hippocampus. Although cannabinoids acutely reduce glutamate release and block hippocampal long-term potentiation (LTP), a potential substrate for learning and memory, the consequences of prolonged exposure to ?9-THC for hippocampal function are poorly understood. Rats were injected with ?9-THC (10 mg/kg, i.p., q.d.) for 1, 3,...

Hoffman, Alexander F.; Oz, Murat; Yang, Ruiqin; Lichtman, Aron H.; Lupica, Carl R.

2007-01-01

363

Long term performance of radon mitigation systems  

International Nuclear Information System (INIS)

Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes

364

Long term results of pneumatic retinopexy  

Directory of Open Access Journals (Sweden)

Full Text Available Amin F EllakwaMenoufiya University, Shibin el Kom, Al-Menoufiya, EgyptBackground: Rhegmatogenous retinal detachment is a commonly encountered retinal problem where rapid treatment can prevent irreversible vision loss. Pneumatic retinopexy (PR is a simple, minimally invasive procedure for retinal reattachment.Purpose: This study aimed to assess the long-term anatomical and functional outcome of pneumatic retinopexy in primary rhegmatogenous retinal detachment.Patients and methods: A prospective interventional study was performed. Subjects with rhegmatogenous retinal detachment who underwent pneumatic retinopexy from May 2006 to May 2007 at Menoufiya University Hospital were included in this study with at least 3 years follow-up.Results: A total of 40 cases were included in the study. The mean age of patients was 44.25 ± 10.85 years. Reattachment of the retina was achieved in 100% of cases. In 75% of cases, the primary intervention was successful. However, the retina redetached in 20% of these during the first 6 months, requiring reinjection or another procedure. Three years after the first intervention, follow-up measurement of the mean visual acuity of the eyes without reoperation was 0.40 ± 0.21 while the mean visual acuity of the eyes which needed additional operations was 0.22 ± 0.13.Conclusion: Sixty percent of the cases obtained long-term retinal reattachment with a single operation success (SOS, with good visual recovery and less morbidity than other more invasive procedures like scleral buckling or pars plana vitrectomy, translating to higher productivity for the patient. This procedure, being quicker than the alternatives, also saves the surgeon's time, making PR a good choice for managing primary rhegmatogenous retinal detachment in developing countries.Keywords: pneumatic, retinopexy, rhegmatogenous, retinal detachment

Ellakwa AF

2012-01-01

365

Long-term dynamics of Typha populations  

Science.gov (United States)

The zonation of Typha populations in an experimental pond in Michigan was re-examined 15 years after the original sampling to gain insight into the long-term dynamics. Current distributions of Typha populations were also examined in additional experimental ponds at the site that have been maintained for 23 years. The zonation between T. latifolia and T. angustifolia in the previously studied pond 15 years after the initial sampling revealed that the density and distribution of shoots had not changed significantly. Thus, it appears that previously reported results (based on 7- year old populations) have remained consistent over time. Additional insight into the interaction between these two taxa was sought by comparing mixed and monoculture stands in five experimental ponds that have remained undisturbed for their 23-year history. The maximum depth of T. latifolia, the shallow- water species, was not significantly reduced when growing in the presence of the more flood tolerant T. angustifolia. In contrast, the minimum depth of T. angustifolia was reduced from 0 to 37 cm when in the presence of T. latifolia. When total populations were compared between monoculture and mixed stands, the average density of T. angustifolia shoots was 59.4 percent lower in mixed stands while the density of T. latifolia was 32 percent lower, with T. angustifolia most affected at shallow depths (reduced by 92 percent) and T. latifolia most affected at the deepest depths (reduced by 60 percent). These long-term observations indicate that competitive displacement between Typha taxa has remained stable over time.

Grace, J.B.; Wetzel, R.G.

1998-01-01

366

Visual Imagery: Effects of Short- and Long-Term Memory  

OpenAIRE

Visual imagery and perception share several functional properties and apparently share common underlying brain structures. A main approach to the scientific study of visual imagery is exploring the effects of mental imagery on perceptual processes. Previous studies have shown that visual imagery interferes with perception (Perky effect). Recently we have shown a direct facilitatory effect of visual imagery on visual perception. In an attempt to differentiate the conditions under which visual ...

Ishai, A.; Sagi, D.

1997-01-01

367

Determining eligibility for long-term care - lessons from Germany  

OpenAIRE

Objectives: This paper addresses recent steps for reforming the eligibility criteria of the German long-term care insurance that have been initiated to overcome shortcomings in the current system.Methods: Based on findings of a survey of international long-term care systems, assessment tools and the relevant literature on care needs a new tool for determining eligibility in the German long-term care insurance was developed.Results: The new tool for determining long-term care eligibility broad...

Andreas Buescher; Klaus Wingenfeld; Doris Schaeffer

2011-01-01

368

LONG-TERM MONITORING SENSOR NETWORK  

Energy Technology Data Exchange (ETDEWEB)

Long-term monitoring (LTM) associated with subsurface contamination sites is a key element of Long Term Stewardship and Legacy Management across the Department of Energy (DOE) complex. However, both within the DOE and elsewhere, LTM is an expensive endeavor, often exceeding the costs of the remediation phase of a clean-up project. The primary contributors to LTM costs are associated with labor. Sample collection, storage, preparation, analysis, and reporting can add a significant financial burden to project expense when extended over many years. Development of unattended, in situ monitoring networks capable of providing quantitative data satisfactory to regulatory concerns has the potential to significantly reduce LTM costs. But survival and dependable operation in a difficult environment is a common obstacle to widespread use across the DOE complex or elsewhere. Deploying almost any sensor in the subsurface for extended periods of time will expose it to chemical and microbial degradation. Over the time-scales required for in situ LTM, even the most advanced sensor systems may be rendered useless. Frequent replacement or servicing (cleaning) of sensors is expensive and labor intensive, offsetting most, if not all, of the cost savings realized with unattended, in situ sensors. To enable facile, remote monitoring of contaminants and other subsurface parameters over prolonged periods, Applied Research Associates, Inc has been working to develop an advanced LTM sensor network consisting of three key elements: (1) an anti-fouling sensor chamber that can accommodate a variety of chemical and physical measurement devices based on electrochemical, optical and other techniques; (2) two rapid, cost effective, and gentle means of emplacing sensor packages either at precise locations directly in the subsurface or in pre-existing monitoring wells; and (3) a web browser-based data acquisition and control system (WebDACS) utilizing field-networked microprocessor-controlled smart sensors housed in anti-fouling sensor chambers. The monitoring network is highly versatile and can be applied to a variety of subsurface sensing scenarios in different media. However, the current project focused on monitoring water quality parameters of pH, oxidation-reduction potential, conductivity, and temperature in groundwater.

Stephen P. Farrington; John W. Haas; Neal Van Wyck

2003-10-16

369

Robotics for Long-Term Monitoring  

International Nuclear Information System (INIS)

While long-term monitoring and stewardship means many things to many people, DOE has defined it as The physical controls, institutions, information, and other mechanisms needed to ensure protection of people and the environment at sites where DOE has completed or plans to complete cleanup (e.g., landfill closures, remedial actions, and facility stabilization). Across the United States, there are thousands of contaminated sites with multiple contaminants released from multiple sources where contaminants have transported and commingled. The U.S. government and U.S. industry are responsible for most of the contamination and are landowners of many of these contaminated properties. These sites must be surveyed periodically for various criteria including structural deterioration, water intrusion, integrity of storage containers, atmospheric conditions, and hazardous substance release. The surveys, however, are intrusive, time-consuming, and expensive and expose survey personnel to radioactive contamination. In long-term monitoring, there's a need for an automated system that will gather and report data from sensors without costly human labor. In most cases, a SCADA (Supervisory Control and Data Acquisition) unit is used to collect and report data from a remote location. A SCADA unit consists of an embedded computer with data acquisition capabilities. The unit can be configured with various sensors placed in different areas of the site to be monitored. A system of this type te to be monitored. A system of this type is static, i.e., the sensors, once placed, cannot be moved to other locations within the site. For those applications where the number of sampling locations would require too many sensors, or where exact location of future problems is unknown, a mobile sensing platform is an ideal solution. In many facilities that undergo regular inspections, the number of video cameras and air monitors required to eliminate the need for human inspections is very large and far too costly. HCET's remote harsh-environment surveyor (RHES) is a robotic platform with SCADA capabilities equipped with a sonar-imaging scanner, a high-resolution color CCD camera, and various combinations of sensors. The RHES is controlled remotely via a PC. This paper will discuss the development and application of this system. (authors)

370

Short- and Long-Term Cognitive Effects of Chronic Cannabinoids Administration in Late-Adolescence Rats  

OpenAIRE

The use of cannabis can impair cognitive function, especially short-term memory. A controversial question is whether long-term cannabis use during the late-adolescence period can cause irreversible deficits in higher brain function that persist after drug use stops. In order to examine the short- and long-term effects of chronic exposure to cannabinoids, rats were administered chronic i.p. treatment with the CB1/CB2 receptor agonist WIN55,212-2 (WIN; 1.2 mg/kg) for two weeks during the late a...

Abush, Hila; Akirav, Irit

2012-01-01

371

Structural basis of long-term potentiation in single dendritic spines  

OpenAIRE

Dendritic spines of pyramidal neurons in the cerebral cortex undergo activity-dependent structural remodelling1–5 that has been proposed to be a cellular basis of learning and memory6. How structural remodelling supports synaptic plasticity4,5, such as long-term potentiation7, and whether such plasticity is input- specific at the level of the individual spine has remained unknown. We investigated the structural basis of long-term potentiation using two-photon photolysis of caged glutamate a...

Matsuzaki, Masanori; Honkura, Naoki; Ellis-davies, Graham C. R.; Kasai, Haruo

2004-01-01

372

Transuranic waste: long-term planning  

International Nuclear Information System (INIS)

Societal concerns for the safe handling and disposal of toxic waste are behind many of the regulations and the control measures in effect today. Transuranic waste, a specific category of toxic (radioactive) waste, serves as a good example of how regulations and controls impact changes in waste processing - and vice versa. As problems would arise with waste processing, changes would be instituted. These changes improved techniques for handling and disposal of transuranic waste, reduced the risk of breached containment, and were usually linked with regulatory changes. Today, however, we face a greater public awareness of and concern for toxic waste control; thus, we must anticipate potential problems and work on resolving them before they can become real problems. System safety analyses are valuable aids in long-term planning for operations involving transuranic as well as other toxic materials. Examples of specific system safety analytical methods demonstrate how problems can be anticipated and resolution initiated in a timely manner having minimal impacts upon allocation of resource and operational goals. 7 refs., 1 fig

373

Long-term predictions using natural analogues  

Energy Technology Data Exchange (ETDEWEB)

One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3}-10{sup 5} years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., {open_quotes}natural analogues{close_quotes}) provide perhaps the only means of partial {open_quotes}validation,{close_quotes} as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (10{sup 3}-10{sup 8} years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the {open_quotes}validation{close_quotes} of performance assessments.

Ewing, R.C. [Univ. of New Mexico, Albuquerque, NM (United States)

1995-09-01

374

Long Term Evolution of Plasma Wakefields  

CERN Document Server

We study the long-term evolution (LTE) of plasma wakefields over multiple plasma-electron periods and few plasma-ion periods, much less than a recombination time. The evolution and relaxation of such a wakefield-perturbed plasma over these timescales has important implications for the upper limits of repetition-rates in plasma colliders. Intense fields in relativistic lasers (or intense beams) create plasma wakefields (modes around {\\omega}pe) by transferring energy to the plasma electrons. Charged-particle beams in the right phase may be accelerated with acceleration/focusing gradients of tens of GeV/m. However, wakefields leave behind a plasma not in equilibrium, with a relaxation time of multiple plasma-electron periods. Ion motion over ion timescales, caused by energy transfer from the driven plasma-electrons to the plasma-ions can create interesting plasma states. Eventually during LTE, the dynamics of plasma de-coheres (multiple modes through instability driven mixing), thermalizing into random motion (...

Sahai, Aakash A; Tsung, F S; Mori, W B

2014-01-01

375

Long term results of mandibular distraction  

Directory of Open Access Journals (Sweden)

Full Text Available Mandibular distraction osteogenesis has become a popular surgical modality due to its many advantages over conventional orthognathic surgical procedures. However, in spite of the technique having been used for over 15 years, no concrete long term results are available regarding the stability of results. We discuss the various studies which have reported either in favour or against the stablility of results after distraction. We report a series of 6 cases (3 unilateral and 3 bilateral distraction where distraction was carried out before puberty and followed them up to seven years after removal of distractors. This case series shows that results achieved by distraction osteogenesis are unstable or best unpredictable with respect to producing a permanent size increase in the mandible. The role of the distraction osteogenesis in overcoming the pterygomassetric sling is questionable. We suggest a multicenter study with adequate patient numbers treated with a similar protocol and documented after growth cessation to have meaningful conclusions on the debate of distraction osteogenesis versus orthognathic surgery.

Batra Puneet

2006-03-01

376

Long-term plutonium storage: Design concepts  

International Nuclear Information System (INIS)

An important part of the Department of Energy (DOE) Weapons Complex Reconfiguration (WCR) Program is the development of facilities for long-term storage of plutonium. The WCR design goals are to provide storage for metals, oxides, pits, and fuel-grade plutonium, including material being held as part of the Strategic Reserve and excess material. Major activities associated with plutonium storage are sorting the plutonium inventory, material handling and storage support, shipping and receiving, and surveillance of material in storage for both safety evaluations and safeguards and security. A variety of methods for plutonium storage have been used, both within the DOE weapons complex and by external organizations. This paper discusses the advantages and disadvantages of proposed storage concepts based upon functional criteria. The concepts discussed include floor wells, vertical and horizontal sleeves, warehouse storage on vertical racks, and modular storage units. Issues/factors considered in determining a preferred design include operational efficiency, maintenance and repair, environmental impact, radiation and criticality safety, safeguards and security, heat removal, waste minimization, international inspection requirements, and construction and operational costs

377

Primary dilated megaureter: long-term followup.  

Science.gov (United States)

Previously, we reported on the changing concepts in the management of 35 neonates with primary obstructive megaureters, 25 of whom were observed without surgery for a mean of 28 months while 10 were surgically treated. We report the long-term outcome of the 25 patients who were managed without surgery. This group consists of 19 male and 6 female neonates with 19 unilateral and 6 bilateral dilated ureters. Of the patients 17 presented with an antenatal diagnosis of hydronephrosis, 2 with infection and 6 with incidental findings. None of the patients had vesicoureteral reflux. Followup serial imaging (2 or more studies per case) consisted of excretory urography in 18 of the 25 cases, diethylenetriaminepentaacetic acid renal scan in 16 and/or sonogram in 10. Mean followup was 7.3 years (range 4.8 to 12.4) for 24 patients and 1 was lost to followup after 1.5 years. Excretory urography showed improvement in urinary tract dilatation in 12 cases and stable dilatation in 6. Renal scans demonstrated expected interval increases in the glomerular filtration rate with age without any deterioration in per cent of renal function in all 16 cases. None of the patients had stones, pain or pyelonephritis. We conclude that it is safe to follow a select group of patients with primary dilated megaureters in the absence of vesicoureteral reflux. We recommend antibiotic prophylaxis and serial urinary tract imaging to confirm renal growth and preservation of renal function. PMID:8021983

Baskin, L S; Zderic, S A; Snyder, H M; Duckett, J W

1994-08-01

378

DIFFERENTIAL DIAGNOSIS OF LONG TERM TONGUE ULCERS  

Directory of Open Access Journals (Sweden)

Full Text Available Oral ulcers is a very common disorder of the oral mucosa. Patients with signs or symptoms of oral ulcers are sometimes referred to gastroenterology clinics, however, in most instances the ulcers does not reflect gastrointestinal disease, some with a chronic non- healing ulcer are advised biopsy. Indeed, a spectrum of disorders can give rise to oral mucosal ulcers ranging from minor local trauma to significant local disease such as malignancy or systemic illness. Lesions of the tongue have a broad differential diagnosis ranging from benign idiopathic processes to infections, cancers, and infiltrative disorders. This article will focus on common ulcerative disorders of the tongue in aspects of their clinical features and differential diagnosis, two case reports with the diagnosis and conservative management for long-term chronic ulcers. The two cases which are reported in this article had a differential diagnosis of Squamous cell carcinoma of the tongue. The clinical picture was craterlike lesion, having a velvety-red base and a rolled, indurated border and most important painless in both cases. Removal of the irritant which was the tooth, rehabilitation of the oral mucosa by lubrication with Cocus Nucifera resulted in the healing of the ulcers. Functional components of Cocus Nucifera are Squaline, tocopherol, phytosterols and other sterols which are all plant steroids.

Hegde Nidarsh D.

2012-08-01

379

Long-term predictions using natural analogues  

International Nuclear Information System (INIS)

One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (103-105 years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., open-quotes natural analoguesclose quotes) provide perhaps the only means of partial open-quotes validation,close quotes as well as data that may be used directly in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (103-108 years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the open-quotes validationclose quotes of performance assessments

380

Long term thermal stability of organic PCMs  

International Nuclear Information System (INIS)

Highlights: • Paraffin based PCM’s have been noted to undergo irreversible physical change with time changing their thermal performance. • The melting point and latent heat of RT21 mixture change while kept at elevated temperatures. • Ester based PCM have shown to have superior thermo-physical characteristics with reduced fire hazardous. - Abstract: Thermal energy storage using phase change materials (PCMs) have been a focal point in the efficient energy utilisation in buildings for over 30 years. The possible use of PCM in buildings is becoming more and more attractive due to the large energy storage density and nearly isothermal nature of the PCM storage when compared to sensible heat storage. Although there is large amount of information available on this topic, literatures show very little information about the long term thermal performance of phase change materials. In this research, changes in thermal characteristics of two commercial organic PCMs when exposed to a constant temperature above their melting point were examined. The thermal characteristic (i.e. melting range and latent heat of fusion) of Rubitherm 21 (RT21, a paraffin mixture) and propyl stearic and palmitate mixture with a melting point in the range of 18–25 °C were tested after an exposure to storage temperatures of 30 and 55 °C. The results obtained indicated that the paraffin based mixture such as RT21 experienced a significant irreversible physical change with time. The data collected and analysis indicated a shift in the peak melting point from 21 to 28 °C and increase in latent heat of fusion from 134 to 170 J/g over a period of 120 days when kept at a temperature of 55 °C. On the other hand, the mixed esters experienced almost no change in mass due to their lower vapour pressure

381

[Long-term intrathecal isobaric morphine therapy].  

Science.gov (United States)

In order to evaluate long-term intrathecal morphine therapy for cancer pain, whatever its location, 121 patients (80% were ambulatory patients) treated between April 1979 and April 1985 at the Cancer Institute of Montpellier (Centre Paul-Lamarque) were assessed. Morphine was stored in a presternal insulin syringe, protected by a sterile and waterproof dressing. A bolus administration of morphine via a subcutaneous lombo-epigastric subarachnoid catheter was scheduled every 12 h. This "closed" device was opened for refilling in an operating room only. The mean follow-up was 68 days (maximum: 13 months). More than 15,000 intrathecal injections were made. The mean daily amount of morphine required was 2.3 mg (extremes: 0.75 and 21 mg). All patients developed tolerance, requiring an adjustment of morphine dosages every 30 to 45 days. With the isobaric morphine solution, good or very good analgesia was achieved in 82% of patients, even in those suffering from thoracic or otolaryngologic pain. Mechanical complications (catheter coming out of the subarachnoid space in 7.67% of cases, leakage of CSF along the catheter in 9.16% of cases) were related to the exteriorization of the proximal catheter tip. With the exception of errors in manipulation, neither infection nor clinical respiratory depression were noticed. Nausea and vomiting were frequent but resolved spontaneously within a few days. Urine retention (33%) occurred mainly in men over 65 years, after pelvic surgery or radiotherapy. Because of the absence of a defined zone of analgesia, the small volumes required and the "ready for use" preparation, intrathecal isobaric morphine therapy will lead to easy self-administration via an implanted pump in the future.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3777564

Gestin, Y; Peré, N; Solassol, C

1986-01-01

382

Delayed administration of alpha-difluoromethylornithine prevents hippocampus-dependent cognitive impairment after single and combined injury in mice.  

Science.gov (United States)

Radiation exposure due to radiological terrorism and military circumstances are a continuing threat for the civilian population. In an uncontrolled radiation event, it is likely that there will be other types of injury involved, including trauma. While radiation combined injury is recognized as an area of great significance, overall there is a paucity of information regarding the mechanisms underlying the interactions between irradiation and other forms of injury, or what countermeasures might be effective in ameliorating such changes. The objective of this study was to determine if difluoromethylornithine (DFMO) could reduce the adverse effects of single or combined injury if administered beginning 24 h after exposure. Eight-week-old C57BL/J6 young-adult male mice received whole-body cesium-137 ((137)Cs) irradiation with 4 Gy. Immediately after irradiation, unilateral traumatic brain injury was induced using a controlled cortical impact system. Forty-four days postirradiation, animals were tested for hippocampus-dependent cognitive performance in the Morris water maze. After cognitive testing, animals were euthanized and their brains snap frozen for immunohistochemical assessment of neuroinflammation (activated microglia) and neurogenesis in the hippocampal dentate gyrus. Our data show that single and combined injuries induced variable degrees of hippocampus-dependent cognitive dysfunction, and when given 24 h post trauma, DFMO treatment ameliorated those effects. Cellular changes including neurogenesis and numbers of activated microglia were generally not associated with the cognitive changes. Further analyses also revealed that DFMO increased hippocampal protein levels of the antioxidants thioredoxin 1 and peroxiredoxin 3 compared to vehicle treated animals. While the mechanisms responsible for the improvement in cognition after DFMO treatment are not yet clear, these results constitute a basis for further development of DFMO as a countermeasure for ameliorating the of risks for cognitive dysfunction in individuals subjected to trauma and radiation combined injury. PMID:25375198

Allen, Antiño R; Eilertson, Kirsten; Sharma, Sourabh; Baure, Jennifer; Allen, Barrett; Leu, David; Rosi, Susanna; Raber, Jacob; Huang, Ting-Ting; Fike, John R

2014-11-01

383

Northern European long term climate archives  

Energy Technology Data Exchange (ETDEWEB)

The Swedish Nuclear Fuel and Waste Management Company is responsible for the management and disposal of Sweden's radioactive waste. It is intended to deposit the spent nuclear fuel in a deep geological repository. This repository shall keep the radiotoxic material separated from humans and the environment for extended periods, from decades to millennia and possibly to geological timescales. During this time perspective climate induced changes such as shore-level displacement and evolution of permafrost and ice sheets are expected to occur which may affect the repository. The possible occurrence, extent and duration of these long-term changes, are therefore of interest when considering the assessment of repository performance and safety. The main climate parameters determining both surface and subsurface conditions are temperature and precipitation. As a result of the last advance of the Weichselian ice sheet only few geological archives exist, which contain information on past climatic conditions in Sweden before c 16,000 years BP. The purpose of this literature review is to compile and evaluate available information from Scandinavian, Northern and Central European geological archives, which record climatic conditions during the Weichselian time period. The compilation provides paleotemperature data sets, which may be used to explore the possible evolution of periglacial permafrost in Sweden. This report is a synopsis of 22 publications detailing climatic and environmental changes during the Weichselian time period in Northwestern Europe based on quantified paleotemperature records. Some of the data is presented as temperature curves which were digitised specifically for this report. The time range covered by the different publications varies considerably. Only few authors dealt with the whole Weichselian period and the majority cover only a few thousand years. This however is not considered to influence the reliability of the archives. The reason for the varying time ranges is that some authors focused on a certain time interval, while others, especially those dealing with sites that had been affected by glaciation only present fragmented sediment sequences. Studies of the flora and climate of the region for the time period before the Last Glacial Maximum (LGM) in Europe have been limited due to the low number of Late Pleniglacial botanical records. The geographical range of this investigation covers North Western Europe from c 47 deg. N to c 78 deg. N and c 10 deg. W to c 30 deg. E. Additional publications, to those detailed in were also reviewed, but were excluded where the chronologies were considered unreliable. The various proxy data used to derive paleotemperatures are primarily: coleoptera, chironomids, pollen, plant macrofossils and periglacial features. In seven of the publications reviewed here a multiproxy approach had been applied.

Hohl, Veronica [Stockholm Univ. (Sweden)

2005-01-01

384

Northern European long term climate archives  

International Nuclear Information System (INIS)

The Swedish Nuclear Fuel and Waste Management Company is responsible for the management and disposal of Sweden's radioactive waste. It is intended to deposit the spent nuclear fuel in a deep geological repository. This repository shall keep the radiotoxic material separated from humans and the environment for extended periods, from decades to millennia and possibly to geological timescales. During this time perspective climate induced changes such as shore-level displacement and evolution of permafrost and ice sheets are expected to occur which may affect the repository. The possible occurrence, extent and duration of these long-term changes, are therefore of interest when considering the assessment of repository performance and safety. The main climate parameters determining both surface and subsurface conditions are temperature and precipitation. As a result of the last advance of the Weichselian ice sheet only few geological archives exist, which contain information on past climatic conditions in Sweden before c 16,000 years BP. The purpose of this literature review is to compile and evaluate available information from Scandinavian, Northern and Central European geological archives, which record climatic conditions during the Weichselian time period. The compilation provides paleotemperature data sets, which may be used to explore the possible evolution of periglacial permafrost in Sweden. This report is a synopsis of 22 publications detailing climatic and environmental changes during the Weichselian time period in Northwestern Europe based on quantified paleotemperature records. Some of the data is presented as temperature curves which were digitised specifically for this report. The time range covered by the different publications varies considerably. Only few authors dealt with the whole Weichselian period and the majority cover only a few thousand years. This however is not considered to influence the reliability of the archives. The reason for the varying time ranges is that some authors focused on a certain time interval, while others, especially those dealing with sites that had been affected by glaciation only present fragmented sediment sequences. Studies of the flora and climate of the region for the time period before the Last Glacial Maximum (LGM) in Europe have been limited due to the low number of Late Pleniglacial botanical records. The geographical range of this investigation covers North Western Europe from c 47 deg. N to c 78 deg. N and c 10 deg. W to c 30 deg. E. Additional publications, to those detailed in were also reviewed, but were excluded where the chronologies were considered unreliable. The various proxy data used to derive paleotemperatures are primarily: coleoptera, chironomids, pollen, plant macrofossils and periglacial features. In seven of the publications reviewed here a multiproxy approach had been applied

385

The long-term management of Canada's used nuclear fuel  

International Nuclear Information System (INIS)

This article describes the long-term management of Canada's used nuclear fuel. The Nuclear Fuel Waste Act passed by the Government of Canada requires the establishment of a nuclear waste management organization operating on a not-for-profit basis to be responsible for the long-term management of irradiated fuel bundles removed from commercial or research fission reactor, and the creation of a trust fund to finance the design, siting, construction, operation and decommissioning of the long-term facility.

386

Long term behaviour of singularly perturbed parabolic degenerated equation  

CERN Document Server

In this paper we consider models for short-term, mean-term and long-term morphodynamics of dunes and megariples. We give an existence and uniqueness result for long term dynamics of dunes. This result is based on a time-space periodic solution existence result for degenerated parabolic equation that we set out. Finally the mean-term and long-term models are homogenized.

Faye, Ibrahima; Seck, Diaraf

2011-01-01

387

Quantification of long term emission potential from landfills:  

OpenAIRE

Novel approaches for the after-care of Municipal Solid Waste (MSW) landfills are based on technological measures to reduce the long term emission potential in a short time period. Biological degradation in landfills is a means to significantly reduce the long term emission potential. Leachate emission to the groundwater is considered to be one of the largest long-term impacts related to landfilling. Currently we are starting up a research program, partly subsidized by the Dutch Technology fou...

Heimovaara, T. J.

2011-01-01

388

Long-term forecast of radioactive polluted of agricultural production  

International Nuclear Information System (INIS)

On the basis of usual radiating conditions in territory of the Mogilev area the long-term forecast of accumulation of cesium-137 in long-term cereal grasses and strontium-90 in grain crops is executed. Now in an agricultural production of area there is a problem of production of long-term cereal grasses with allowable levels of the contents of cesium-137 for manufacture of whole milk and a food grain with the allowable contents of strontium-90. The long-term forecast of pollution of production with radionuclide is executed on an example of most polluted facilities of Kostyukovichskij, Krasnopol'skij and Slavgorodskij areas. (Authors)

389

Consider long-term care as service alternative.  

Science.gov (United States)

The increasing demand for elderly care services, pressures on inpatient average length of stay and payment levels, and potential financial rewards from providing additional services, makes long-term care look attractive to hospitals. Long-term care, however, is not for every hospital. Before deciding to establish long-term care services, management should examine how the service fits within the hospital's strategic plan. The action plan below provides guidance in evaluating a decision to use hospital facilities for long-term care. Examine how long-term care services fit within the hospital's strategic plan. Study area demographics and competitors to assess the need and supply of long-term care services. Survey the medical staff, consumers and payers to determine attitudes, perceptions and interests regarding long-term care services. Develop a facility plan that identifies areas of excess capacity that can be most easily converted into long-term care with minimal effects on hospital operations. Prepare a financial feasibility analysis of the contribution margin and return on investment attributable to long-term care services. Include an impact analysis on hospital operations. Establish a management task force to develop a detailed implementation plan including assigned individual responsibilities and related timetable. Develop an effective marketing plan designed to generate increased patient market share. PMID:10312056

Loria, L S

1987-04-01

390

Long-term persistence of vaccine-derived aluminum hydroxide is associated with chronic cognitive dysfunction.  

Science.gov (United States)

Macrophagic myofasciitis (MMF) is an emerging condition, characterized by specific muscle lesions assessing long-term persistence of aluminum hydroxide within macrophages at the site of previous immunization. Affected patients mainly complain of arthromyalgias, chronic fatigue, and cognitive difficulties. We designed a comprehensive battery of neuropsychological tests to prospectively delineate MMF-associated cognitive dysfunction (MACD). Compared to control patients with arthritis and chronic pain, MMF patients had pronounced and specific cognitive impairment. MACD mainly affected (i) both visual and verbal memory; (ii) executive functions, including attention, working memory, and planning; and (iii) left ear extinction at dichotic listening test. Cognitive deficits did not correlate with pain, fatigue, depression, or disease duration. Pathophysiological mechanisms underlying MACD remain to be determined. In conclusion, long-term persistence of vaccine-derived aluminum hydroxide within the body assessed by MMF is associated with cognitive dysfunction, not solely due to chronic pain, fatigue and depression. PMID:19748679

Couette, Maryline; Boisse, Marie-Françoise; Maison, Patrick; Brugieres, Pierre; Cesaro, Pierre; Chevalier, Xavier; Gherardi, Romain K; Bachoud-Levi, Anne-Catherine; Authier, François-Jérôme

2009-11-01

391

Herpes simplex encephalitis: long term magnetic resonance imaging and neuropsychological profile.  

OpenAIRE

The first comprehensive in vivo documentation of the long term profile of pathological and spared tissue is described in a group of 10 patients with a diagnosis of herpes simplex encephalitis, who were left with memory difficulties as a major residual sequel of their condition. With a dedicated MRI protocol, which included high resolution images of temporal lobe and limbic system areas, data are provided on structures that have recently gained importance as anatomical substrates for amnesia. ...

Kapur, N.; Barker, S.; Burrows, E. H.; Ellison, D.; Brice, J.; Illis, L. S.; Scholey, K.; Colbourn, C.; Wilson, B.; Loates, M.

1994-01-01

392

ANDRA's sustainable development annual report: From strategy to first actions: the ANDRA's long term commitment  

International Nuclear Information System (INIS)

This brochure is a communication document which aims at highlighting the strategy and the actions of ANDRA (the French national agency for radioactive waste management) for a committed governance (at the company level, in its consultancy and monitoring activities, with respect to human resources), for a sustainable activity (monitoring, storage ecological footprint, storage very long term memory, knowledge sharing, environment survey), and for a citizen company (energy savings and carbon assessment, eco-responsible purchases)

393

Long-term Neuroplasticity Effects of Febrile Seizures in the Developing Brain  

OpenAIRE

Febrile seizures (FS) are the most common seizure disorderin childhood, occurring in 2%-5% of children. Regardingthe large number of children with FS, it is important to delineatewhether early-life FS alters long-term neuroplasticity,especially the neurocognitive function and subsequent temporallobe epilepsy (TLE). Recent epidemiological studies reassurethat most FS do not adversely affect global intelligenceand hippocampal function, such as memory. However, thereare concerns regarding those ...

Ying-Chao Chang; Chao-Ching Huang; Song-Chei Huang

2008-01-01

394

Inducible molecular switches for the study of long-term potentiation.  

OpenAIRE

This article reviews technical and conceptual advances in unravelling the molecular bases of long-term potentiation (LTP), learning and memory using genetic approaches. We focus on studies aimed at testing a model suggesting that protein kinases and protein phosphatases balance each other to control synaptic strength and plasticity. We describe how gene 'knock-out' technology was initially exploited to disrupt the Ca(2+)/calmodulin-dependent protein kinase IIalpha (CaMKIIalpha) gene and how r...

He?dou, Gae?l; Mansuy, Isabelle M.

2003-01-01

395

Abeta oligomer-mediated long-term potentiation impairment involves protein phosphatase 1-dependent mechanisms  

OpenAIRE

Amyloid beta (Abeta) oligomers are derived from proteolytic cleavage of amyloid precursor protein (APP) and can impair memory and hippocampal long-term potentiation (LTP) in vivo and in vitro. They are recognized as the primary neurotoxic agents in Alzheimer's disease. The mechanisms underlying such toxicity on synaptic functions are complex and not fully understood. Here, we provide the first evidence that these mechanisms involve protein phosphatase 1 (PP1). Using a novel transgenic mouse m...

Knobloch, M.; Farinelli, M.; Konietzko, U.; Nitsch, R. M.; Mansuy, I. M.

2007-01-01

396

Long-Term Control Medications for Lung Diseases  

Science.gov (United States)

... Quick-Relief Medications Long-Term Control Medications Anti-IgE Treatment Combination Medications Inhaled Steroids About Steroids Leukotriene ... types of long-term control asthma medications: Anti-IgE Anti-IgE is a form of treatment for ...

397

[Developing the core competencies of long-term care professionals].  

Science.gov (United States)

Longer average life expectancies and an ageing society have made long-term care an urgent and important issue in Taiwan. Although the implementation of Long-Term Care Ten-year Project four years ago has begun showing success in terms of assessing Taiwan's needs in terms of long-term care services and resources, there has been little forward progress in terms of training, recruiting and maintaining more competent professionals in the long-term care sector. This paper explores the current state of long-term care competency in Taiwan and educational strategies in place to improve the competency of long-term care professionals. Results indicate that the term geriatric competency embraces sub-competencies in direct care, communication, assessment, teamwork, cultural sensitivities and career care competencies. The term long-term care competency embraces the sub-competencies of supervision, management, information technology, resource management, and organizational skill. As a main contributor to effective long-term care, the nursing profession must employ effective strategies to develop competency-based education. Also, the profession must have an adequate supply of competent manpower to effectively respond to Taiwan's aging society. PMID:23212250

Chen, Huey-Tzy; Lee, Kuang-Ting

2012-12-01

398

Factors Affecting Long-Term Abstinence from Substances Use  

Science.gov (United States)

Objective: The purpose of this study is to explore the attitudes of abstainers from drug use that relate to the factors leading to long-term abstinence. Materials and Methods: Cross-sectional study was carried out in Al-Amal Hospital to examine, which attitudes of abstainers related to long-term abstinence. A random survey was conducted on 62…

Elsheikh, Salah Elgaily

2008-01-01

399

Angiotensin?converting enzyme inhibitor fetopathy: long?term outcome  

OpenAIRE

Fetal exposure to angiotensin?converting enzyme inhibitors (ACEIs) is associated with increased neonatal morbidity and mortality. Long?term follow?up of three patients with fetal ACEI exposure revealed impaired renal function in two, severe hypertension and proteinuria in one and isolated polycythaemia in all three. Careful long?term follow?up of children with ACEI fetopathy is recommended.

Laube, Guido F.; Kemper, Markus J.; Schubiger, Gregor; Neuhaus, Thomas J.

2007-01-01

400

40 CFR 52.29 - Visibility long-term strategies.  

Science.gov (United States)

...visibility program (40 CFR 51.301). (c) Long-term...goal specified in § 51.300(a). This strategy...identified according to § 51.304. (2) The...long-term strategies developed for each visibility protection area. The review and...

2010-07-01

401

Engagement of the PFC in Consolidation and Recall of Recent Spatial Memory  

Science.gov (United States)

The standard model of system consolidation proposes that memories are initially hippocampus dependent and become hippocampus independent over time. Previous studies have demonstrated the involvement of the medial prefrontal cortex (mPFC) in the retrieval of remote memories. The transformations required to make a memory undergo system's…

Leon, Wanda C.; Bruno, Martin A.; Allard, Simon; Nader, Karim; Cuello, A. Claudio

2010-01-01

402

Alcohol inhibition of the NMDA receptor function, long-term potentiation, and fear learning requires striatal-enriched protein tyrosine phosphatase  

OpenAIRE

Alcohol's deleterious effects on memory are well known. Acute alcohol-induced memory loss is thought to occur via inhibition of NMDA receptor (NMDAR)-dependent long-term potentiation in the hippocampus. We reported previously that ethanol inhibition of NMDAR function and long-term potentiation is correlated with a reduction in the phosphorylation of Tyr1472 on the NR2B subunit and ethanol's inhibition of the NMDAR field excitatory postsynaptic potential was attenuated by a broad spectrum tyro...

Hicklin, Tianna R.; Wu, Peter H.; Radcliffe, Richard A.; Freund, Ronald K.; Goebel-goody, Susan M.; Correa, Paulo R.; Proctor, William R.; Lombroso, Paul J.; Browning, Michael D.

2011-01-01

403

A universal long-term flu vaccine may not prevent severe epidemics  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Recently, the promise of a new universal long-term flu vaccine has become more tangible than ever before. Such a vaccine would protect against very many seasonal and pandemic flu strains for many years, making annual vaccination unnecessary. However, due to complacency behavior, it remains unclear whether the introduction of such vaccines would maintain high and stable levels of vaccination coverage year after year. Findings To predict the impact of universal long-term flu vaccines on influenza epidemics we developed a mathematical model that linked human cognition and memory with the transmission dynamics of influenza. Our modeling shows that universal vaccines that provide short-term protection are likely to result in small frequent epidemics, whereas universal vaccines that provide long-term protection are likely to result in severe infrequent epidemics. Conclusions Influenza vaccines that provide short-term protection maintain risk awareness regarding influenza in the population and result in stable vaccination coverage. Vaccines that provide long-term protection could lead to substantial drops in vaccination coverage and should therefore include an annual epidemic risk awareness programs in order to minimize the risk of severe epidemics.

Blower Sally

2010-04-01

404

Long-Term Stewardship Baseline Report and Transition Guidance  

Energy Technology Data Exchange (ETDEWEB)

Long-term stewardship consists of those actions necessary to maintain and demonstrate continued protection of human health and the environment after facility cleanup is complete. As the Department of Energy’s (DOE) lead laboratory for environmental management programs, the Idaho National Engineering and Environmental Laboratory (INEEL) administers DOE’s long-term stewardship science and technology efforts. The INEEL provides DOE with technical, and scientific expertise needed to oversee its long-term environmental management obligations complexwide. Long-term stewardship is administered and overseen by the Environmental Management Office of Science and Technology. The INEEL Long-Term Stewardship Program is currently developing the management structures and plans to complete INEEL-specific, long-term stewardship obligations. This guidance document (1) assists in ensuring that the program leads transition planning for the INEEL with respect to facility and site areas and (2) describes the classes and types of criteria and data required to initiate transition for areas and sites where the facility mission has ended and cleanup is complete. Additionally, this document summarizes current information on INEEL facilities, structures, and release sites likely to enter long-term stewardship at the completion of DOE’s cleanup mission. This document is not intended to function as a discrete checklist or local procedure to determine readiness to transition. It is an overarching document meant as guidance in implementing specific transition procedures. Several documents formed the foundation upon which this guidance was developed. Principal among these documents was the Long-Term Stewardship Draft Technical Baseline; A Report to Congress on Long-Term Stewardship, Volumes I and II; Infrastructure Long-Range Plan; Comprehensive Facility Land Use Plan; INEEL End-State Plan; and INEEL Institutional Plan.

Kristofferson, Keith

2001-11-01

405

Long-term ecological research: An international perspective  

International Nuclear Information System (INIS)

This book is the result of two international workshops sponsored by Scientific Committee on Problems of the Environment (SCOPE). Thirteen of sixteen chapters cover the first three objectives of the workshops: analysis of examples of long term ecological research sites and networks from several countries; refining the rationale for long-term research; and identifying current and emerging questions with particular regard to global environmental change. Chapter 14 explores the issue of international communication and coordination among long-term research sites. Of interest is the contrast between chapters written by USA authors and those describing projects from elsewhere

406

Psychological status of COPD patients before and after one year of long-term oxygen therapy.  

Science.gov (United States)

Cognitive function, psychological status, and attitudes were investigated in 90 patients with chronic obstructive pulmonary disease before the initiation of long-term oxygen therapy and after one year of treatment. Assessment included clinical interview, Wechsler Intelligence Scale I.Q., Bourdon-Wiersma Test, Benton Verbal Retention Test, Rey's Test of Remembering 15 Words, Beck's Depression Scale, Taylor's Manifest Anxiety Scale, and Tylka's Psychological Evaluation Scale of the Effectiveness of Rehabilitation. The mean I.Q. of the patients studied was slightly above average at 107 points. Tests of cognitive function showed reduced performance. These included tests of repeating numbers, pictorial anecdotes and numerical symbols. Rey's Test of Word Memory was also below average but increased following treatment. In the Bourdon Test, there were 58 correct deletions and 7 omissions initially, improving to 67 and 8, respectively, after treatment. Poor visual and spatial memory did not improve after treatment. Before treatment, patients demonstrated depressed mood, low self-esteem with narrow interests, signs of anxiety, mental stress and depression. After a year of long-term oxygen therapy significant improvements in mood and attitudes were demonstrated. We conclude that long-term oxygen therapy may be capable of producing a significant improvement in emotional status. However, the effects of oxygen treatment are difficult to separate from effects of other aspects of care in producing a sense of increased security and well-being. PMID:8901313

Borak, J; Sliwi?ski, P; Tobiasz, M; Górecka, D; Zieli?ski, J

1996-02-01

407

Cognitive differences in schizophrenia on long-term treatments with clozapine, risperidone and typical antipsychotics.  

Science.gov (United States)

Cognitive deficits are a core feature of schizophrenia. There is ongoing debate on whether cognition is affected by antipsychotic drugs (APDs). This study examined the effect of long-term treatment with APDs on cognition in schizophrenia. Cognitive function was assessed in 418 patients with schizophrenia on long-term treatment with APDs (215 on clozapine, 91 on risperidone and 112 on typical APDs) and 159 healthy controls using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Schizophrenia symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS). We found that cognitive test scores were significantly lower in all patients compared with the healthy controls on almost all of the total and subscores of RBANS (all P<0.001), except for the visuospatial/constructional index. Individuals taking clozapine showed worse immediate and delayed memory performance than those taking typical APDs (all P<0.01). Moreover, individuals taking clozapine showed better language performance than those taking risperidone (P<0.01). Immediate memory and delayed memory were modestly correlated with the types of APDs and the PANSS negative scores. Our results show that individuals taking clozapine performed worse in immediate and delayed memory than those taking typical APDs, but exemplified better language performance than those taking risperidone. PMID:25568968

Han, Mei; Zhang, Xiang Yang; Chen, Da Chun; Tan, Yun Long; Song, Chong Sheng; Yu, Ying Hua; Huang, Xu Feng

2015-03-01

408

Maged1 Co-interacting with CREB Through a Hexapeptide Repeat Domain Regulates Learning and Memory in Mice.  

Science.gov (United States)

Maged1 is a member of the type II melanoma antigen (MAGE) family of proteins, which is highly conserved in the brain between mouse and human. Recently, Maged1 has been reported to be involved in depression and impaired sexual behavior. However, the role of Maged1 in learning and memory remains unknown. The aim of the present study was therefore to investigate whether Maged1 deficiency can impair learning and memory formation. By behavioral tests and electrophysiological recording, we observed that 5-6-month-old Maged1 knockout mice displayed the reduced basal synaptic transmission, pronounced hippocampal dysfunction, impaired spatial learning, and a deficit in long-term potentiation induction. Data from immunohistochemical and Western blot showed the reduced dendritic spine density and the number of synapses in the hippocampus of the Maged1 knockout mice, and Maged1 deficiency prevented the interaction of Maged1 with cAMP response element-binding protein (CREB). Furthermore, by chromatin immunoprecipitation and luciferase assay, we observed the downregulated activity of CREB and the suppressed CREB-dependent transcription after deficiency of Maged1, which lead to the decreased levels of brain-derived neurotrophic factor. Taken together, our results provide the evidence that Maged1 is involved in synaptic transmission and hippocampus-dependent learning and memory formation. PMID:24700102

Yang, JianJun; Lai, BeiBei; Xu, AiLi; Liu, Yu; Li, XiaoMin; Zhao, YongNa; Li, WeiFeng; Ji, MuHuo; Hu, Gang; Gao, Xiang; Gao, Jun

2015-02-01

409

Hospital attendance patterns in long term survivors of cancer  

OpenAIRE

Aims: To identify attendance patterns in a childhood cancer long term follow up clinic, in order to inform decision making strategies for efficient, cost effective local and national surveillance of survivors.

Johnson, R.; Horne, B.; Feltbower, R.; Butler, G.; Glaser, A.

2004-01-01

410

7 CFR 1773.44 - Long-term debt.  

Science.gov (United States)

...DEPARTMENT OF AGRICULTURE (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Required Audit Procedures and Documentation § 1773.44 Long-term...Examined notes executed or canceled during the audit period; and (d) Tested accrued...

2010-01-01

411

Endovascular techniques for placement of long-term chemotherapy catheters  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE: To analyze the results from using endovascular techniques to place long-term chemotherapy catheters when advancing the catheter using the external jugular vein is difficult due to obstructions or kinking. METHODS: Between July 1997 and August 2000, 320 long-term chemotherapy catheters were placed, and in 220 cases the external jugular vein was used as the primary venous approach. In 18 of these patients, correct positioning was not achieved and several endovascular techniques were then utilized to overcome these obstacles, including manipulation of a J-wire with a moveable core, venography, and the exchange wire technique. RESULTS: In 94.5% of the patients with difficulties in obtaining the correct positioning, we were able to advance the long-term catheter to the desired position with the assistance of endovascular techniques. CONCLUSIONS: Venography and endovascular guidance techniques are useful for the placement of long-term catheters in the external jugular vein.

Yazbek Guilherme

2003-01-01

412

Long-Term Ecological Monitoring Field Sampling Plan for 2007  

Energy Technology Data Exchange (ETDEWEB)

This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used t determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality.

T. Haney

2007-07-31

413

Long-Term Stewardship Science and Technology Requirements  

International Nuclear Information System (INIS)

To ensure technology developed for long-term stewardship will meet existing requirements, a review of requirements was performed. In addition to identifying existing science and technology related requirements, gaps and conflicts of requirements were identified

414

Long-Term Ecological Monitoring Field Sampling Plan for 2007  

International Nuclear Information System (INIS)

This field sampling plan describes the field investigations planned for the Long-Term Ecological Monitoring Project at the Idaho National Laboratory Site in 2007. This plan and the Quality Assurance Project Plan for Waste Area Groups 1, 2, 3, 4, 5, 6, 7, 10, and Removal Actions constitute the sampling and analysis plan supporting long-term ecological monitoring sampling in 2007. The data collected under this plan will become part of the long-term ecological monitoring data set that is being collected annually. The data will be used to determine the requirements for the subsequent long-term ecological monitoring. This plan guides the 2007 investigations, including sampling, quality assurance, quality control, analytical procedures, and data management. As such, this plan will help to ensure that the resulting monitoring data will be scientifically valid, defensible, and of known and acceptable quality

415

Long-Term Stewardship Science and Technology Requirements  

Energy Technology Data Exchange (ETDEWEB)

To ensure technology developed for long-term stewardship will meet existing requirements, a review of requirements was performed. In addition to identifying existing science and technology related requirements, gaps and conflicts of requirements were identified.

McDonald, J.K.; Nickelson, R.A.

2002-05-16

416

Long-term Stewardship Science and Technology Requirements  

Energy Technology Data Exchange (ETDEWEB)

To ensure technology developed for long-term stewardship will meet existing requirements, a review of requirements was performed. In addition to identifying existing science and technology related requirements, gaps and conflicts of requirements were identified.

Mcdonald, Jaimee Kristen; Nickelson, Reva Anne

2002-08-01

417

Managing Care for Adults with Long-Term Medical Illness  

Science.gov (United States)

... for patients with psychiatric illnesses such as depression, schizophrenia, or bipolar disorder. For information about case management ... AHRQ), a Federal Government research agency, reviewed 109 studies on case management for people with long-term medical illnesses ...

418

Opposing Actions of Chronic[Deta][superscript 9] Tetrahydrocannabinol and Cannabinoid Antagonists on Hippocampal Long-Term Potentiation  

Science.gov (United States)

Memory deficits produced by marijuana arise partly via interaction of the psychoactive component, [Deta][superscript 9]-tetrahydrocannabinol ([Deta][superscript 9]-THC), with cannabinoid receptors in the hippocampus. Although cannabinoids acutely reduce glutamate release and block hippocampal long-term potentiation (LTP), a potential substrate for…

Hoffman, Alexander F.; Oz, Murat; Yang, Ruiqin; Lichtman, Aron H.; Lupica, Carl R.

2007-01-01

419

Gallic Acid Improves Cognitive, Hippocampal Long-term Potentiation Deficits and Brain Damage Induced by Chronic Cerebral Hypoperfusion in Rats  

OpenAIRE

Cerebral Hypoperfusion Ischemia (CHI) has important role in neuronal damage and behavioral deficits, including memory and Long-term Potentiation (LTP) impairment. Protective effects of Gallic Acid (GA) on memory, hippocampus LTP and cell viability were examined in permanent bilateral common carotid artery occlusion in rats. Animals were divided into 9 groups: Control (Cont); sham operated (Sho); Cerebral Hypoperfusion Ischemia (CHI); CHI received normal saline ...

Sarkaki, A.; Fathimoghaddam, H.; Mansouri, S. M. T.; Shahrani Korrani, M.; Saki, G.; Farbood, Y.

2014-01-01

420

Hygrothermal long-term behavior assessment for building elements  

OpenAIRE

The paper started, based on the results of INCD URBAN INCERC Iasi research project, from a series of questions raised by the long term assessment for the hygrothermal behavior of building elements, often belonging to cultural heritage. The paper refers, to the efficient methods for investigation, to analyze possible solutions, in the project proposals for intervention works. As an option are the non invasive solutions to a long term assessment, most often qualitative, through numerical simula...

Victoria Cotorobai; Alina Cobzaru

2013-01-01

421

A perspective on long-term care for the elderly  

OpenAIRE

Long-term care represents a significant burden to the approximately 7 million elderly in need, their families, and the Medicaid program. Concerns exist about access, quality, cost, and the distribution of the burden of care. In this article each area is discussed, highlighting the principal issues, identifying the unique aspects that pertain to long-term care, and exploring the implications for research and policy development. Future trends, especially the growth of the elderly population, ar...

Scanlon, William J.

1988-01-01

422

Influential Factors in Long-term Product Service System Contracts  

OpenAIRE

This dissertation presents different aspects of long-term contract for product service system (PSS); also different issues that companies are dealt for implementation of PSS. The study consists of literature review for understanding factors which can affect long-term PSS contracts. Different generic categories of green business models which are used in PSS contracts have been addressed and in addition, various models of contracts for PSS in industries have been identified too. The important f...

Hosseini Taklimi, Seyed Reza

2011-01-01

423

Cyclical Long-term Unemployment, Skill Loss, and Monetary Policy  

OpenAIRE

Movements in long-term unemployment (LTU) exhibit a substantial cyclical component. I develop a business cycle model featuring labor market frictions and skill loss during unemployment to capture various stylized facts about the cyclical behavior of long-term unemployment. I find that the skill loss mechanism helps reproduce negative duration dependence, high persistence in unemployment and output, volatility patterns across macroeconomic variables and the behavior of the incidence of LTU aro...

Daniel Kienzler

2012-01-01

424

A new image for long-term care.  

Science.gov (United States)

To counter widely held negative images of long-term care, managers in the industry should implement quality-improvement initiatives that include six key strategies: Manage the expectations of residents and their families. Address customers' concerns early. Build long-term customer satisfaction. Allocate resources to achieve exceptional outcomes in key areas. Respond to adverse events with compassion. Reinforce the facility's credibility. PMID:15098291

Wager, Richard; Creelman, William

2004-04-01

425

Seamless Long Term Learning in Agile Teams for Sustainable Leadership  

CERN Document Server

Seamless and continuous support for long term organizational learning needs is essential for long lasting progress of the organization. Agile process model provides an excellent opportunity to cater that specific problem and also helps in motivation, satisfaction, coordination, presentation and technical skills enhancement of agile teams. This long term learning process makes organization to sustain their current successes and lead both organization and team members to successful and dynamic market leaders.

Qureshi, M R J

2012-01-01

426

A long-term outcome study of intersex conditions.  

OpenAIRE

CONTEXT: Clinical management of intersex conditions is controversial because the available evidence is limited and conflicting, with no long-term population based studies comparing matched controls. OBJECTIVE: To assess the long-term psychological, sexual and social outcomes of patients with intersex compared with two matched control populations. DESIGN, SETTING AND PARTICIPANTS: Three different aged-matched (18-32 years) patient groups completed a self-administered questionnaire of establish...

Warne, G.; Grover, S.; Hutson, J.; Sinclair, A.; Metcalfe, S.; Northam, E.; Freeman, J.

2005-01-01

427

DSpace@Cambridge: implementing long-term digital preservation  

OpenAIRE

DSpace@Cambridge is an institutional archive set up to deal with the long-term preservation of information in a wide range of formats over an indefinite period of time. In this paper we look at some long-term digital preservation strategies, as they are currently implemented in our archive. We describe the value of documentation of file format specifications for future data accessibility. We examine the impact and usefulness of constant concurrent data migration to several different ...

Mulder, Tom

2005-01-01

428

Long-Term Changes in Chemostat Cultures of Cytophaga johnsonae  

OpenAIRE

Long-term studies with a gliding, heterotrophic bacterium, Cytophaga johnsonae, were conducted in a glucose-limited chemostat at a high and a low dilution rate. To test the stability of the steady state during long-term experiments the following parameters were monitored: optical density, glucose concentration, glucose uptake potential, ATP content of the cells, and plate counts on two different agar media. Biomass remained relatively constant, although the observed changes could have been po...

Ho?fle, Manfred G.

1983-01-01

429

Sustainable Goals : Feasible Paths to Desirable Long-Term Futures  

OpenAIRE

The general aim of this licentiate thesis is to analyze the framework in which long-term goals are set and subsequently achieved. It is often claimed that goals should be realistic, meaning that they should be adjusted to known abilities. This thesis will argue that this might be very difficult in areas related to sustainable development and climate change adaptation, and that goals that are, to an acceptable degree, unrealistic, can have important functions. Essay I discusses long-term goal ...

Baard, Patrik

2014-01-01

430

Long-term care insurance: an essential employee benefit.  

Science.gov (United States)

Growing numbers of employers are embracing long-term care insurance (LTCI) as an important new addition to their employee benefits package due to aging baby boomers, tax favorable legislation, the need for employee retention and rising costs of care. Even the best retirement plans can be gutted by the high costs of long-term care. The authors identify key components of LTCI and offer guidelines for selecting an LTCI company. PMID:12500583

Gordon, Murray; Gordon, Brian

2002-12-01

431

Principles of Long-Term Dynamics of Dendritic Spines  

OpenAIRE

Long-term potentiation (LTP) of synapse strength requires enlargement of dendritic spines on cerebral pyramidal neurons. Long-term depression (LTD) is linked to spine shrinkage. Indeed, spines are dynamic structures: they form, change their shapes and volumes or can disappear in the space of hours. Do all such changes result from synaptic activity, or do some changes result from intrinsic processes? How do enlargement and shrinkage of spines relate to elimination and generation of spines, and...

Yasumatsu, Nobuaki; Matsuzaki, Masanori; Miyazaki, Takashi; Noguchi, Jun; Kasai, Haruo

2008-01-01