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Sample records for facilitate memory formation

  1. Fasting launches CRTC to facilitate long-term memory formation in Drosophila.

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    Hirano, Yukinori; Masuda, Tomoko; Naganos, Shintaro; Matsuno, Motomi; Ueno, Kohei; Miyashita, Tomoyuki; Horiuchi, Junjiro; Saitoe, Minoru

    2013-01-25

    Canonical aversive long-term memory (LTM) formation in Drosophila requires multiple spaced trainings, whereas appetitive LTM can be formed after a single training. Appetitive LTM requires fasting prior to training, which increases motivation for food intake. However, we found that fasting facilitated LTM formation in general; aversive LTM formation also occurred after single-cycle training when mild fasting was applied before training. Both fasting-dependent LTM (fLTM) and spaced training-dependent LTM (spLTM) required protein synthesis and cyclic adenosine monophosphate response element-binding protein (CREB) activity. However, spLTM required CREB activity in two neural populations--mushroom body and DAL neurons--whereas fLTM required CREB activity only in mushroom body neurons. fLTM uses the CREB coactivator CRTC, whereas spLTM uses the coactivator CBP. Thus, flies use distinct LTM machinery depending on their hunger state.

  2. Fear Conditioning Downregulates Rac1 Activity in the Basolateral Amygdala Astrocytes to Facilitate the Formation of Fear Memory.

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    Liao, Zhaohui; Tao, Yezheng; Guo, Xiaomu; Cheng, Deqin; Wang, Feifei; Liu, Xing; Ma, Lan

    2017-01-01

    Astrocytes are well known to scale synaptic structural and functional plasticity, while the role in learning and memory, such as conditioned fear memory, is poorly elucidated. Here, using pharmacological approach, we find that fluorocitrate (FC) significantly inhibits the acquisition of fear memory, suggesting that astrocyte activity is required for fear memory formation. We further demonstrate that fear conditioning downregulates astrocytic Rac1 activity in basolateral amygdala (BLA) in mice and promotes astrocyte structural plasticity. Ablation of astrocytic Rac1 in BLA promotes fear memory acquisition, while overexpression or constitutive activation of astrocytic Rac1 attenuates fear memory acquisition. Furthermore, temporal activation of Rac1 by photoactivatable Rac1 (Rac1-PA) induces structural alterations in astrocytes and in vivo activation of Rac1 in BLA astrocytes during fear conditioning attenuates the formation of fear memory. Taken together, our study demonstrates that fear conditioning-induced suppression of BLA astrocytic Rac1 activity, associated with astrocyte structural plasticity, is required for the formation of conditioned fear memory.

  3. Anodal tDCS over the Primary Motor Cortex Facilitates Long-Term Memory Formation Reflecting Use-Dependent Plasticity.

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    Orjon Rroji

    Full Text Available Previous research suggests that anodal transcranial direct current stimulation (tDCS over the primary motor cortex (M1 modulates NMDA receptor dependent processes that mediate synaptic plasticity. Here we test this proposal by applying anodal versus sham tDCS while subjects practiced to flex the thumb as fast as possible (ballistic movements. Repetitive practice of this task has been shown to result in performance improvements that reflect use-dependent plasticity resulting from NMDA receptor mediated, long-term potentiation (LTP-like processes. Using a double-blind within-subject cross-over design, subjects (n=14 participated either in an anodal or a sham tDCS session which were at least 3 months apart. Sham or anodal tDCS (1 mA was applied for 20 min during motor practice and retention was tested 30 min, 24 hours and one week later. All subjects improved performance during each of the two sessions (p < 0.001 and learning gains were similar. Our main result is that long term retention performance (i.e. 1 week after practice was significantly better when practice was performed with anodal tDCS than with sham tDCS (p < 0.001. This effect was large (Cohen's d=1.01 and all but one subject followed the group trend. Our data strongly suggest that anodal tDCS facilitates long-term memory formation reflecting use-dependent plasticity. Our results support the notion that anodal tDCS facilitates synaptic plasticity mediated by an LTP-like mechanism, which is in accordance with previous research.

  4. DNA methylation and memory formation.

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    Day, Jeremy J; Sweatt, J David

    2010-11-01

    Memory formation and storage require long-lasting changes in memory-related neuronal circuits. Recent evidence indicates that DNA methylation may serve as a contributing mechanism in memory formation and storage. These emerging findings suggest a role for an epigenetic mechanism in learning and long-term memory maintenance and raise apparent conundrums and questions. For example, it is unclear how DNA methylation might be reversed during the formation of a memory, how changes in DNA methylation alter neuronal function to promote memory formation, and how DNA methylation patterns differ between neuronal structures to enable both consolidation and storage of memories. Here we evaluate the existing evidence supporting a role for DNA methylation in memory, discuss how DNA methylation may affect genetic and neuronal function to contribute to behavior, propose several future directions for the emerging subfield of neuroepigenetics, and begin to address some of the broader implications of this work.

  5. Emotion processing facilitates working memory performance.

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    Lindström, Björn R; Bohlin, Gunilla

    2011-11-01

    The effect of emotional stimulus content on working memory performance has been investigated with conflicting results, as both emotion-dependent facilitation and impairments are reported in the literature. To clarify this issue, 52 adult participants performed a modified visual 2-back task with highly arousing positive stimuli (sexual scenes), highly arousing negative stimuli (violent death) and low-arousal neutral stimuli. Emotional stimulus processing was found to facilitate task performance relative to that of neutral stimuli, both in regards to response accuracy and reaction times. No emotion-dependent differences in false-alarm rates were found. These results indicate that emotional information can have a facilitating effect on working memory maintenance and processing of information.

  6. Nicotine facilitates memory consolidation in perceptual learning.

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    Beer, Anton L; Vartak, Devavrat; Greenlee, Mark W

    2013-01-01

    Perceptual learning is a special type of non-declarative learning that involves experience-dependent plasticity in sensory cortices. The cholinergic system is known to modulate declarative learning. In particular, reduced levels or efficacy of the neurotransmitter acetylcholine were found to facilitate declarative memory consolidation. However, little is known about the role of the cholinergic system in memory consolidation of non-declarative learning. Here we compared two groups of non-smoking men who learned a visual texture discrimination task (TDT). One group received chewing tobacco containing nicotine for 1 h directly following the TDT training. The other group received a similar tasting control substance without nicotine. Electroencephalographic recordings during substance consumption showed reduced alpha activity and P300 latencies in the nicotine group compared to the control group. When re-tested on the TDT the following day, both groups responded more accurately and more rapidly than during training. These improvements were specific to the retinal location and orientation of the texture elements of the TDT suggesting that learning involved early visual cortex. A group comparison showed that learning effects were more pronounced in the nicotine group than in the control group. These findings suggest that oral consumption of nicotine enhances the efficacy of nicotinic acetylcholine receptors. Our findings further suggest that enhanced efficacy of the cholinergic system facilitates memory consolidation in perceptual learning (and possibly other types of non-declarative learning). In that regard acetylcholine seems to affect consolidation processes in perceptual learning in a different manner than in declarative learning. Alternatively, our findings might reflect dose-dependent cholinergic modulation of memory consolidation. This article is part of a Special Issue entitled 'Cognitive Enhancers'. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Facilitation of memory by contextual cues in patients with diencephalic or medial temporal lobe dysfunction.

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    Tielemans, N.S.; Hendriks, M.P.; Talamini, L.; Wester, A.J.; Meeter, M.; Kessels, R.P.C.

    2012-01-01

    Item-context binding is crucial for successful episodic memory formation, and binding deficits have been suggested to underlie episodic-memory deficits. Here, our research investigated the facilitation of cued recall and recognition memory by contextual cues in 20 patients with Korsakoff's amnesia,

  8. Facilitation of memory by contextual cues in patients with diencephalic or medial temporal lobe dysfunction

    NARCIS (Netherlands)

    Tielemans, N.S.; Hendriks, M.P.H.; Talamini, L.; Wester, A.J.; Meeter, M.; Kessels, R.P.C.

    2012-01-01

    Item-context binding is crucial for successful episodic memory formation, and binding deficits have been suggested to underlie episodic-memory deficits. Here, our research investigated the facilitation of cued recall and recognition memory by contextual cues in 20 patients with Korsakoff's amnesia,

  9. Audiovisual integration facilitates monkeys' short-term memory.

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    Bigelow, James; Poremba, Amy

    2016-07-01

    Many human behaviors are known to benefit from audiovisual integration, including language and communication, recognizing individuals, social decision making, and memory. Exceptionally little is known about the contributions of audiovisual integration to behavior in other primates. The current experiment investigated whether short-term memory in nonhuman primates is facilitated by the audiovisual presentation format. Three macaque monkeys that had previously learned an auditory delayed matching-to-sample (DMS) task were trained to perform a similar visual task, after which they were tested with a concurrent audiovisual DMS task with equal proportions of auditory, visual, and audiovisual trials. Parallel to outcomes in human studies, accuracy was higher and response times were faster on audiovisual trials than either unisensory trial type. Unexpectedly, two subjects exhibited superior unimodal performance on auditory trials, a finding that contrasts with previous studies, but likely reflects their training history. Our results provide the first demonstration of a bimodal memory advantage in nonhuman primates, lending further validation to their use as a model for understanding audiovisual integration and memory processing in humans.

  10. Learned Interval Time Facilitates Associate Memory Retrieval

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    van de Ven, Vincent; Kochs, Sarah; Smulders, Fren; De Weerd, Peter

    2017-01-01

    The extent to which time is represented in memory remains underinvestigated. We designed a time paired associate task (TPAT) in which participants implicitly learned cue-time-target associations between cue-target pairs and specific cue-target intervals. During subsequent memory testing, participants showed increased accuracy of identifying…

  11. Latent memory facilitates relearning through molecular signaling mechanisms that are distinct from original learning.

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    Menges, Steven A; Riepe, Joshua R; Philips, Gary T

    2015-09-01

    A highly conserved feature of memory is that it can exist in a latent, non-expressed state which is revealed during subsequent learning by its ability to significantly facilitate (savings) or inhibit (latent inhibition) subsequent memory formation. Despite the ubiquitous nature of latent memory, the mechanistic nature of the latent memory trace and its ability to influence subsequent learning remains unclear. The model organism Aplysia californica provides the unique opportunity to make strong links between behavior and underlying cellular and molecular mechanisms. Using Aplysia, we have studied the mechanisms of savings due to latent memory for a prior, forgotten experience. We previously reported savings in the induction of three distinct temporal domains of memory: short-term (10min), intermediate-term (2h) and long-term (24h). Here we report that savings memory formation utilizes molecular signaling pathways that are distinct from original learning: whereas the induction of both original intermediate- and long-term memory in naïve animals requires mitogen activated protein kinase (MAPK) activation and ongoing protein synthesis, 2h savings memory is not disrupted by inhibitors of MAPK or protein synthesis, and 24h savings memory is not dependent on MAPK activation. Collectively, these findings reveal that during forgetting, latent memory for the original experience can facilitate relearning through molecular signaling mechanisms that are distinct from original learning. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Short-term facilitation may stabilize parametric working memory trace

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    Vladimir eItskov

    2011-10-01

    Full Text Available Networks with continuous set of attractors are considered to be a paradigmatic model for parametric working memory, but require fine-tuning of connections and are thus structurally unstable. Here we analyzed the network with ring attractor, where connections are not perfectly tuned and the activity state therefore drifts in the absence of the stabilizing stimulus. We derive an analytical expression for the drift dynamics and conclude that the network cannot function as working memory for a period of several seconds, a typical delay time in monkey memory experiments. We propose that short-term synaptic facilitation in recurrent connections significantly improves the robustness of the model by slowing down the drift of activity bump. Extending the calculation of the drift velocity to network with synaptic facilitation, we conclude that facilitation can slow down the drift by a large factor, rendering the network suitable as a model of working memory.

  13. Nogo receptor 1 regulates formation of lasting memories

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    Karlén, Alexandra; Karlsson, Tobias E.; Mattsson, Anna; Lundströmer, Karin; Codeluppi, Simone; Pham, Therese M.; Bäckman, Cristina M.; Ögren, Sven Ove; Åberg, Elin; Hoffman, Alexander F.; Sherling, Michael A.; Lupica, Carl R.; Hoffer, Barry J.; Spenger, Christian; Josephson, Anna; Brené, Stefan; Olson, Lars

    2009-01-01

    Formation of lasting memories is believed to rely on structural alterations at the synaptic level. We had found that increased neuronal activity down-regulates Nogo receptor-1 (NgR1) in brain regions linked to memory formation and storage, and postulated this to be required for formation of lasting memories. We now show that mice with inducible overexpression of NgR1 in forebrain neurons have normal long-term potentiation and normal 24-h memory, but severely impaired month-long memory in both passive avoidance and swim maze tests. Blocking transgene expression normalizes these memory impairments. Nogo, Lingo-1, Troy, endogenous NgR1, and BDNF mRNA expression levels were not altered by transgene expression, suggesting that the impaired ability to form lasting memories is directly coupled to inability to down-regulate NgR1. Regulation of NgR1 may therefore serve as a key regulator of memory consolidation. Understanding the molecular underpinnings of synaptic rearrangements that carry lasting memories may facilitate development of treatments for memory dysfunction. PMID:19915139

  14. What Do They Understand? Using Technology to Facilitate Formative Assessment

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    Mitten, Carolyn; Jacobbe, Tim; Jacobbe, Elizabeth

    2017-01-01

    Formative assessment is so important to inform teachers' planning. A discussion of the benefits of using technology to facilitate formative assessment explains how four primary school teachers adopted three different apps to make their formative assessment more meaningful and useful.

  15. Timely sleep facilitates declarative memory consolidation in infants

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    Seehagen, Sabine; Konrad, Carolin; Herbert, Jane S.; Schneider, Silvia

    2015-01-01

    The potential benefits of infant sleep for memory processing are largely unexplored. Here we show evidence that having an extended nap (≥30 min) within 4 h of learning helps 6- and 12-month-old infants to retain their memories for new behaviors across a 4- and 24-h delay. These results suggest that infants rely on frequent naps for the formation of long-term memories.

  16. Formation and suppression of acoustic memories during human sleep.

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    Andrillon, Thomas; Pressnitzer, Daniel; Léger, Damien; Kouider, Sid

    2017-08-08

    Sleep and memory are deeply related, but the nature of the neuroplastic processes induced by sleep remains unclear. Here, we report that memory traces can be both formed or suppressed during sleep, depending on sleep phase. We played samples of acoustic noise to sleeping human listeners. Repeated exposure to a novel noise during Rapid Eye Movements (REM) or light non-REM (NREM) sleep leads to improvements in behavioral performance upon awakening. Strikingly, the same exposure during deep NREM sleep leads to impaired performance upon awakening. Electroencephalographic markers of learning extracted during sleep confirm a dissociation between sleep facilitating memory formation (light NREM and REM sleep) and sleep suppressing learning (deep NREM sleep). We can trace these neural changes back to transient sleep events, such as spindles for memory facilitation and slow waves for suppression. Thus, highly selective memory processes are active during human sleep, with intertwined episodes of facilitative and suppressive plasticity.Though memory and sleep are related, it is still unclear whether new memories can be formed during sleep. Here, authors show that people could learn new sounds during REM or light non-REM sleep, but that learning was suppressed when sounds were played during deep NREM sleep.

  17. Preliminary evidence that glucose ingestion facilitates prospective memory performance.

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    Riby, Leigh M; Law, Anna S; McLaughlin, Jennifer; Murray, Jennifer

    2011-05-01

    Previous research has found that the ingestion of glucose boosts task performance in the memory domain (including tasks tapping episodic, semantic, and working memory). The present pilot study tested the hypothesis that glucose ingestion would enhance performance on a test of prospective memory. In a between-subjects design, 56 adults ranging from 17 to 80 years of age performed a computerized prospective memory task and an attention (filler) task after 25 g of glucose or a sweetness-matched placebo. Blood glucose measurements were also taken to assess the impact of individual differences on glucose regulation. After the drink containing glucose, cognitive facilitation was observed on the prospective memory task after excluding subjects with impaired fasting glucose level. Specifically, subjects receiving glucose were 19% more accurate than subjects receiving a placebo, a trend that was marginally nonsignificant, F₁,₄₁ = 3.4, P = .07, but that had a medium effect size, d = 0.58. Subjects receiving glucose were also significantly faster on the prospective memory task, F₁,₃₅ = 4.8, P glucose (indicative of poor glucose regulation) was associated with slower prospective memory responding, F₁,₃₅ = 4.4, P memory and executive functioning can benefit from the increased provision of glucose to the brain. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. A facilitative effect of negative affective valence on working memory.

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    Gotoh, Fumiko; Kikuchi, Tadashi; Olofsson, Ulrich

    2010-06-01

    Previous studies have shown that negatively valenced information impaired working memory performance due to an attention-capturing effect. The present study examined whether negative valence could also facilitate working memory. Affective words (negative, neutral, positive) were used as retro-cues in a working memory task that required participants to remember colors at different spatial locations on a computer screen. Following the cue, a target detection task was used to either shift attention to a different location or keep attention at the same location as the retro-cue. Finally, participants were required to discriminate the cued color from a set of distractors. It was found that negative cues yielded shorter response times (RTs) in the attention-shift condition and longer RTs in the attention-stay condition, compared with neutral and positive cues. The results suggest that negative affective valence may enhance working memory performance (RTs), provided that attention can be disengaged.

  19. Paradoxical facilitation of working memory after basolateral amygdala damage.

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    Barak Morgan

    Full Text Available Working memory is a vital cognitive capacity without which meaningful thinking and logical reasoning would be impossible. Working memory is integrally dependent upon prefrontal cortex and it has been suggested that voluntary control of working memory, enabling sustained emotion inhibition, was the crucial step in the evolution of modern humans. Consistent with this, recent fMRI studies suggest that working memory performance depends upon the capacity of prefrontal cortex to suppress bottom-up amygdala signals during emotional arousal. However fMRI is not well-suited to definitively resolve questions of causality. Moreover, the amygdala is neither structurally or functionally homogenous and fMRI studies do not resolve which amygdala sub-regions interfere with working memory. Lesion studies on the other hand can contribute unique causal evidence on aspects of brain-behaviour phenomena fMRI cannot "see". To address these questions we investigated working memory performance in three adult female subjects with bilateral basolateral amygdala calcification consequent to Urbach-Wiethe Disease and ten healthy controls. Amygdala lesion extent and functionality was determined by structural and functional MRI methods. Working memory performance was assessed using the Wechsler Adult Intelligence Scale-III digit span forward task. State and trait anxiety measures to control for possible emotional differences between patient and control groups were administered. Structural MRI showed bilateral selective basolateral amygdala damage in the three Urbach-Wiethe Disease subjects and fMRI confirmed intact functionality in the remaining amygdala sub-regions. The three Urbach-Wiethe Disease subjects showed significant working memory facilitation relative to controls. Control measures showed no group anxiety differences. Results are provisionally interpreted in terms of a 'cooperation through competition' networks model that may account for the observed paradoxical

  20. Verifying visual properties in sentence verification facilitates picture recognition memory.

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    Pecher, Diane; Zanolie, Kiki; Zeelenberg, René

    2007-01-01

    According to the perceptual symbols theory (Barsalou, 1999), sensorimotor simulations underlie the representation of concepts. We investigated whether recognition memory for pictures of concepts was facilitated by earlier representation of visual properties of those concepts. During study, concept names (e.g., apple) were presented in a property verification task with a visual property (e.g., shiny) or with a nonvisual property (e.g., tart). Delayed picture recognition memory was better if the concept name had been presented with a visual property than if it had been presented with a nonvisual property. These results indicate that modality-specific simulations are used for concept representation.

  1. Externalising the autobiographical self: sharing personal memories online facilitated memory retention.

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    Wang, Qi; Lee, Dasom; Hou, Yubo

    2017-07-01

    Internet technology provides a new means of recalling and sharing personal memories in the digital age. What is the mnemonic consequence of posting personal memories online? Theories of transactive memory and autobiographical memory would make contrasting predictions. In the present study, college students completed a daily diary for a week, listing at the end of each day all the events that happened to them on that day. They also reported whether they posted any of the events online. Participants received a surprise memory test after the completion of the diary recording and then another test a week later. At both tests, events posted online were significantly more likely than those not posted online to be recalled. It appears that sharing memories online may provide unique opportunities for rehearsal and meaning-making that facilitate memory retention.

  2. Pre-stimulus thalamic theta power predicts human memory formation.

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    Sweeney-Reed, Catherine M; Zaehle, Tino; Voges, Jürgen; Schmitt, Friedhelm C; Buentjen, Lars; Kopitzki, Klaus; Richardson-Klavehn, Alan; Hinrichs, Hermann; Heinze, Hans-Jochen; Knight, Robert T; Rugg, Michael D

    2016-09-01

    Pre-stimulus theta (4-8Hz) power in the hippocampus and neocortex predicts whether a memory for a subsequent event will be formed. Anatomical studies reveal thalamus-hippocampal connectivity, and lesion, neuroimaging, and electrophysiological studies show that memory processing involves the dorsomedial (DMTN) and anterior thalamic nuclei (ATN). The small size and deep location of these nuclei have limited real-time study of their activity, however, and it is unknown whether pre-stimulus theta power predictive of successful memory formation is also found in these subcortical structures. We recorded human electrophysiological data from the DMTN and ATN of 7 patients receiving deep brain stimulation for refractory epilepsy. We found that greater pre-stimulus theta power in the right DMTN was associated with successful memory encoding, predicting both behavioral outcome and post-stimulus correlates of successful memory formation. In particular, significant correlations were observed between right DMTN theta power and both frontal theta and right ATN gamma (32-50Hz) phase alignment, and frontal-ATN theta-gamma cross-frequency coupling. We draw the following primary conclusions. Our results provide direct electrophysiological evidence in humans of a role for the DMTN as well as the ATN in memory formation. Furthermore, prediction of subsequent memory performance by pre-stimulus thalamic oscillations provides evidence that post-stimulus differences in thalamic activity that index successful and unsuccessful encoding reflect brain processes specifically underpinning memory formation. Finally, the findings broaden the understanding of brain states that facilitate memory encoding to include subcortical as well as cortical structures. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. GSK-3β and Memory Formation

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    Akihiko eTakashima

    2012-04-01

    Full Text Available In Alzheimer’s disease (AD, tau hyperphosphorylation and neurofibrillary tangle (NFT formation are strongly associated with dementia. Memory impairment is a characteristic, early symptom of AD. Glycogen synthase kinase 3 β (GSK-3β, which is activated in response to amyloid β (Aβ formation, and the normal process of aging, hyperphosphorylates tau present in the NFTs. Furthermore, activation of GSK-3β inhibits synaptic long-term potentiation (LTP through tau. It is therefore likely, that activation of GSK-3β is responsible for the memory problems seen in both advanced age, and AD. Indeed, inhibition of GSK-3 by lithium halts the progression of symptoms in patients with mild cognitive impairment (MCI. However, long-term treatment of lithium increases the risk of dementia in old age, in bipolar patients. To understand the role of GSK-3β in brain function, we analyzed memory formation in GSK-3β heterozygote, knockout mice. Results indicate that these mice show impaired memory reconsolidation. It would seem that activation of GSK-3β is required for memory maintenance, with a higher requirement as animals age, and the volume of memory increases. This in turn causes exaggerated activation of GSK-3β, leading to memory problems, and the formation of NFTs.

  4. Part-set cueing impairment & facilitation in semantic memory.

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    Kelley, Matthew R; Parihar, Sushmeena A

    2018-01-19

    The present study explored the influence of part-set cues in semantic memory using tests of "free" recall, reconstruction of order, and serial recall. Nine distinct categories of information were used (e.g., Zodiac signs, Harry Potter books, Star Wars films, planets). The results showed part-set cueing impairment for all three "free" recall sets, whereas part-set cueing facilitation was evident for five of the six ordered sets. Generally, the present results parallel those often observed across episodic tasks, which could indicate that similar mechanisms contribute to part-set cueing effects in both episodic and semantic memory. A novel anchoring explanation of part-set cueing facilitation in order and spatial tasks is provided.

  5. Language Mediated Concept Activation in Bilingual Memory Facilitates Cognitive Flexibility

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    Anatoliy V. Kharkhurin

    2017-06-01

    Full Text Available This is the first attempt of empirical investigation of language mediated concept activation (LMCA in bilingual memory as a cognitive mechanism facilitating divergent thinking. Russian–English bilingual and Russian monolingual college students were tested on a battery of tests including among others Abbreviated Torrance Tests for Adults assessing divergent thinking traits and translingual priming (TLP test assessing the LMCA. The latter was designed as a lexical decision priming test, in which a prime and a target were not related in Russian (language of testing, but were related through their translation equivalents in English (spoken only by bilinguals. Bilinguals outperformed their monolingual counterparts on divergent thinking trait of cognitive flexibility, and bilinguals’ performance on this trait could be explained by their TLP effect. Age of second language acquisition and proficiency in this language were found to relate to the TLP effect, and therefore were proposed to influence the directionality and strength of connections in bilingual memory.

  6. Egocentric-updating during navigation facilitates episodic memory retrieval.

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    Gomez, Alice; Rousset, Stéphane; Baciu, Monica

    2009-11-01

    Influential models suggest that spatial processing is essential for episodic memory [O'Keefe, J., & Nadel, L. (1978). The hippocampus as a cognitive map. London: Oxford University Press]. However, although several types of spatial relations exist, such as allocentric (i.e. object-to-object relations), egocentric (i.e. static object-to-self relations) or egocentric updated on navigation information (i.e. self-to-environment relations in a dynamic way), usually only allocentric representations are described as potentially subserving episodic memory [Nadel, L., & Moscovitch, M. (1998). Hippocampal contributions to cortical plasticity. Neuropharmacology, 37(4-5), 431-439]. This study proposes to confront the allocentric representation hypothesis with an egocentric updated with self-motion representation hypothesis. In the present study, we explored retrieval performance in relation to these two types of spatial processing levels during learning. Episodic remembering has been assessed through Remember responses in a recall and in a recognition task, combined with a "Remember-Know-Guess" paradigm [Gardiner, J. M. (2001). Episodic memory and autonoetic consciousness: A first-person approach. Philosophical Transactions of the Royal Society B: Biological Sciences, 356(1413), 1351-1361] to assess the autonoetic level of responses. Our results show that retrieval performance was significantly higher when encoding was performed in the egocentric-updated condition. Although egocentric updated with self-motion and allocentric representations are not mutually exclusive, these results suggest that egocentric updating processing facilitates remember responses more than allocentric processing. The results are discussed according to Burgess and colleagues' model of episodic memory [Burgess, N., Becker, S., King, J. A., & O'Keefe, J. (2001). Memory for events and their spatial context: models and experiments. Philosophical Transactions of the Royal Society of London. Series B

  7. Memory, expectation formation and scheduling choices

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    Koster, P.R.; Peer, S.; Dekker, T.

    2015-01-01

    Limited memory capacity, retrieval constraints and anchoring are central to expectation formation processes. We develop a model of adaptive expectations where individuals are able to store only a finite number of past experiences of a stochastic state variable. Retrieval of these experiences is

  8. Epigenetic Regulation of Memory Formation and Maintenance

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    Zovkic, Iva B.; Guzman-Karlsson, Mikael C.; Sweatt, J. David

    2013-01-01

    Understanding the cellular and molecular mechanisms underlying the formation and maintenance of memories is a central goal of the neuroscience community. It is well regarded that an organism's ability to lastingly adapt its behavior in response to a transient environmental stimulus relies on the central nervous system's capability for structural…

  9. Glucose enhancement of human memory: a comprehensive research review of the glucose memory facilitation effect.

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    Smith, Michael A; Riby, Leigh M; Eekelen, J Anke M van; Foster, Jonathan K

    2011-01-01

    The brain relies upon glucose as its primary fuel. In recent years, a rich literature has developed from both human and animal studies indicating that increases in circulating blood glucose can facilitate cognitive functioning. This phenomenon has been termed the 'glucose memory facilitation effect'. The purpose of this review is to discuss a number of salient studies which have investigated the influence of glucose ingestion on neurocognitive performance in individuals with (a) compromised neurocognitive capacity, as well as (b) normally functioning individuals (with a focus on research conducted with human participants). The proposed neurocognitive mechanisms purported to underlie the modulatory effect of glucose on neurocognitive performance will also be considered. Many theories have focussed upon the hippocampus, given that this brain region is heavily implicated in learning and memory. Further, it will be suggested that glucose is a possible mechanism underlying the phenomenon that enhanced memory performance is typically observed for emotionally laden stimuli. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Interaction of Inhibitory and Facilitatory Effects of Conditioning Trials on Long-Term Memory Formation

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    Hosono, Shouhei; Matsumoto, Yukihisa; Mizunami, Makoto

    2016-01-01

    Animals learn through experience and consolidate the memories into long-time storage. Conditioning parameters to induce protein synthesis-dependent long-term memory (LTM) have been the subject of extensive studies in many animals. Here we found a case in which a conditioning trial inhibits or facilitates LTM formation depending on the intervals…

  11. On the opinion formation of mobile agents with memory

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    Zhang, Yunhong; Liu, Qipeng; Wang, Zhenling; Zhang, Siying

    2018-02-01

    This paper studies the opinion formation problem in a group of mobile agents using a multi-agent modeling method. Suppose that all agents move in a two-dimensional space following a certain rule. The interaction range of each agent is determined by its physical location and its opinion similarity with other agents. Moreover, agents have memory of the opinions of their previous interactive neighbors. We investigate the influence of three factors on the formation of group opinion: moving probability, interactive radius, and population density. Using simulations, we find that an opinion consensus can be achieved easily under a small moving probability and a small interactive radius, which is a relatively counterintuitive phenomenon. We also find that a large interactive radius or the model with memory can facilitate the convergence of opinions in a group to either consensus or clusters.

  12. Stabilization of memory States by stochastic facilitating synapses.

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    Miller, Paul

    2013-12-06

    Bistability within a small neural circuit can arise through an appropriate strength of excitatory recurrent feedback. The stability of a state of neural activity, measured by the mean dwelling time before a noise-induced transition to another state, depends on the neural firing-rate curves, the net strength of excitatory feedback, the statistics of spike times, and increases exponentially with the number of equivalent neurons in the circuit. Here, we show that such stability is greatly enhanced by synaptic facilitation and reduced by synaptic depression. We take into account the alteration in times of synaptic vesicle release, by calculating distributions of inter-release intervals of a synapse, which differ from the distribution of its incoming interspike intervals when the synapse is dynamic. In particular, release intervals produced by a Poisson spike train have a coefficient of variation greater than one when synapses are probabilistic and facilitating, whereas the coefficient of variation is less than one when synapses are depressing. However, in spite of the increased variability in postsynaptic input produced by facilitating synapses, their dominant effect is reduced synaptic efficacy at low input rates compared to high rates, which increases the curvature of neural input-output functions, leading to wider regions of bistability in parameter space and enhanced lifetimes of memory states. Our results are based on analytic methods with approximate formulae and bolstered by simulations of both Poisson processes and of circuits of noisy spiking model neurons.

  13. Facilitating the formation of accountable care organizations in rural areas.

    Science.gov (United States)

    Baloh, Jure; Zhu, Xi; Vaughn, Tom; MacKinney, A Clinton; Mueller, Keith J; Ullrich, Fred; Nattinger, Matthew

    2014-07-01

    This Policy Brief presents characteristics contributing to the formation of four accountable care organizations (ACOs) that serve rural Medicare beneficiaries. Doing so provides considerations for provider organizations contemplating creating rural-based ACOs. Key Findings. (1) Previous organizational integration and risk-sharing experience facilitated ACO formation. (2) Use of an electronic health record system fostered core ACO capabilities, including care coordination and population health management. (3) Partnerships across the care continuum supported utilization of local health care resources.

  14. Memory processing and the glucose facilitation effect: the effects of stimulus difficulty and memory load.

    Science.gov (United States)

    Meikle, Andrew; Riby, Leigh M; Stollery, Brian

    2005-08-01

    Previous research has consistently found enhancement of memory after the ingestion of a glucose containing drink. The aims of the present study were to specify more precisely the nature of this facilitation by examining the cognitive demand hypothesis. This hypothesis predicts greater glucose induced facilitation on tasks that require significant mental effort. In two experiments, both employing an unrelated sample design, participants consumed either 25 g of glucose or a control solution. In experiment 1, participants first studied low and high imagery word-pairs and memory was assessed 1-, 7- and 14-days later by cued recall. Overall, glucose enhanced both encoding and consolidation processes only for the more difficult low imagery pairs. In experiment 2, the degree of mental effort in a verbal memory task was manipulated in two ways: (1) by varying the phonological similarity of the words; and (2) by varying the length of word lists. Glucose was found to enhance memory only for longer word lists. These data are consistent with the idea that glucose is especially effective in demanding memory tasks, but place some limits on the forms of difficulty that are susceptible to enhancement.

  15. Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum

    OpenAIRE

    Johnson, A.J.; Miles, C.

    2007-01-01

    The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum, however a context dependent effect was not found with chewing gum. The findings contradict previous ...

  16. Evidence against memorial facilitation and context-dependent memory effects through the chewing of gum.

    Science.gov (United States)

    Johnson, Andrew J; Miles, Christopher

    2007-05-01

    The experiment examined the prediction that chewing gum at learning and/or recall facilitated subsequent word recall. Chewing gum at learning significantly impaired recall, indicating that the chewing of gum has a detrimental impact upon initial word encoding. In addition, a context-dependent memory effect was reported for those participants who both learned and recalled in the absence of gum; however, a context-dependent effect was not found with chewing gum. The findings contradict previous research.

  17. Sleep deprivation increases formation of false memory.

    Science.gov (United States)

    Lo, June C; Chong, Pearlynne L H; Ganesan, Shankari; Leong, Ruth L F; Chee, Michael W L

    2016-12-01

    Retrieving false information can have serious consequences. Sleep is important for memory, but voluntary sleep curtailment is becoming more rampant. Here, the misinformation paradigm was used to investigate false memory formation after 1 night of total sleep deprivation in healthy young adults (N = 58, mean age ± SD = 22.10 ± 1.60 years; 29 males), and 7 nights of partial sleep deprivation (5 h sleep opportunity) in these young adults and healthy adolescents (N = 54, mean age ± SD = 16.67 ± 1.03 years; 25 males). In both age groups, sleep-deprived individuals were more likely than well-rested persons to incorporate misleading post-event information into their responses during memory retrieval (P memory during sleep curtailment, and suggest the need to assess eyewitnesses' sleep history after encountering misleading information. © 2016 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

  18. Piracetam, an AMPAkine drug, facilitates memory consolidation in the day-old chick.

    Science.gov (United States)

    Samartgis, Jodi R; Schachte, Leslie; Hazi, Agnes; Crowe, Simon F

    2012-12-01

    Piracetam is an AMPAkine drug that may have a range of different mechanisms at the cellular level, and which has been shown to facilitate memory, amongst its other effects. This series of experiments demonstrated that a 10mg/kg dose of piracetam facilitated memory consolidation in the day-old chick when injected from immediately until 120min after weak training (i.e. using a 20% v/v concentration of methyl anthranilate) with the passive avoidance learning task. Administration of piracetam immediately after training led to memory facilitation which lasted for up to 24h following training. This dose of the AMPAkine was not shown to facilitate memory reconsolidation. These findings support the contention that application of the AMPAkine piracetam facilitates memory using a weak training task, and extend the range of actions previously noted with NMDA-related agents to those which also facilitate the AMPA receptor. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. Neocortical connectivity during episodic memory formation.

    Science.gov (United States)

    Summerfield, Christopher; Greene, Matthew; Wager, Tor; Egner, Tobias; Hirsch, Joy; Mangels, Jennifer

    2006-05-01

    During the formation of new episodic memories, a rich array of perceptual information is bound together for long-term storage. However, the brain mechanisms by which sensory representations (such as colors, objects, or individuals) are selected for episodic encoding are currently unknown. We describe a functional magnetic resonance imaging experiment in which participants encoded the association between two classes of visual stimuli that elicit selective responses in the extrastriate visual cortex (faces and houses). Using connectivity analyses, we show that correlation in the hemodynamic signal between face- and place-sensitive voxels and the left dorsolateral prefrontal cortex is a reliable predictor of successful face-house binding. These data support the view that during episodic encoding, "top-down" control signals originating in the prefrontal cortex help determine which perceptual information is fated to be bound into the new episodic memory trace.

  20. Neocortical connectivity during episodic memory formation.

    Directory of Open Access Journals (Sweden)

    Christopher Summerfield

    2006-05-01

    Full Text Available During the formation of new episodic memories, a rich array of perceptual information is bound together for long-term storage. However, the brain mechanisms by which sensory representations (such as colors, objects, or individuals are selected for episodic encoding are currently unknown. We describe a functional magnetic resonance imaging experiment in which participants encoded the association between two classes of visual stimuli that elicit selective responses in the extrastriate visual cortex (faces and houses. Using connectivity analyses, we show that correlation in the hemodynamic signal between face- and place-sensitive voxels and the left dorsolateral prefrontal cortex is a reliable predictor of successful face-house binding. These data support the view that during episodic encoding, "top-down" control signals originating in the prefrontal cortex help determine which perceptual information is fated to be bound into the new episodic memory trace.

  1. Connected Classroom Technology Facilitates Multiple Components of Formative Assessment Practice

    Science.gov (United States)

    Shirley, Melissa L.; Irving, Karen E.

    2015-02-01

    Formative assessment has been demonstrated to result in increased student achievement across a variety of educational contexts. When using formative assessment strategies, teachers engage students in instructional tasks that allow the teacher to uncover levels of student understanding so that the teacher may change instruction accordingly. Tools that support the implementation of formative assessment strategies are therefore likely to enhance student achievement. Connected classroom technologies (CCTs) include a family of devices that show promise in facilitating formative assessment. By promoting the use of interactive student tasks and providing both teachers and students with rapid and accurate data on student learning, CCT can provide teachers with necessary evidence for making instructional decisions about subsequent lessons. In this study, the experiences of four middle and high school science teachers in their first year of implementing the TI-Navigator™ system, a specific type of CCT, are used to characterize the ways in which CCT supports the goals of effective formative assessment. We present excerpts of participant interviews to demonstrate the alignment of CCT with several main phases of the formative assessment process. CCT was found to support implementation of a variety of instructional tasks that generate evidence of student learning for the teacher. The rapid aggregation and display of student learning evidence provided teachers with robust data on which to base subsequent instructional decisions.

  2. Dynamics of Hippocampal Protein Expression During Long-term Spatial Memory Formation*

    Science.gov (United States)

    Borovok, Natalia; Nesher, Elimelech; Levin, Yishai; Reichenstein, Michal; Pinhasov, Albert

    2016-01-01

    Spatial memory depends on the hippocampus, which is particularly vulnerable to aging. This vulnerability has implications for the impairment of navigation capacities in older people, who may show a marked drop in performance of spatial tasks with advancing age. Contemporary understanding of long-term memory formation relies on molecular mechanisms underlying long-term synaptic plasticity. With memory acquisition, activity-dependent changes occurring in synapses initiate multiple signal transduction pathways enhancing protein turnover. This enhancement facilitates de novo synthesis of plasticity related proteins, crucial factors for establishing persistent long-term synaptic plasticity and forming memory engrams. Extensive studies have been performed to elucidate molecular mechanisms of memory traces formation; however, the identity of plasticity related proteins is still evasive. In this study, we investigated protein turnover in mouse hippocampus during long-term spatial memory formation using the reference memory version of radial arm maze (RAM) paradigm. We identified 1592 proteins, which exhibited a complex picture of expression changes during spatial memory formation. Variable linear decomposition reduced significantly data dimensionality and enriched three principal factors responsible for variance of memory-related protein levels at (1) the initial phase of memory acquisition (165 proteins), (2) during the steep learning improvement (148 proteins), and (3) the final phase of the learning curve (123 proteins). Gene ontology and signaling pathways analysis revealed a clear correlation between memory improvement and learning phase-curbed expression profiles of proteins belonging to specific functional categories. We found differential enrichment of (1) neurotrophic factors signaling pathways, proteins regulating synaptic transmission, and actin microfilament during the first day of the learning curve; (2) transcription and translation machinery, protein

  3. Dynamics of Hippocampal Protein Expression During Long-term Spatial Memory Formation.

    Science.gov (United States)

    Borovok, Natalia; Nesher, Elimelech; Levin, Yishai; Reichenstein, Michal; Pinhasov, Albert; Michaelevski, Izhak

    2016-02-01

    Spatial memory depends on the hippocampus, which is particularly vulnerable to aging. This vulnerability has implications for the impairment of navigation capacities in older people, who may show a marked drop in performance of spatial tasks with advancing age. Contemporary understanding of long-term memory formation relies on molecular mechanisms underlying long-term synaptic plasticity. With memory acquisition, activity-dependent changes occurring in synapses initiate multiple signal transduction pathways enhancing protein turnover. This enhancement facilitates de novo synthesis of plasticity related proteins, crucial factors for establishing persistent long-term synaptic plasticity and forming memory engrams. Extensive studies have been performed to elucidate molecular mechanisms of memory traces formation; however, the identity of plasticity related proteins is still evasive. In this study, we investigated protein turnover in mouse hippocampus during long-term spatial memory formation using the reference memory version of radial arm maze (RAM) paradigm. We identified 1592 proteins, which exhibited a complex picture of expression changes during spatial memory formation. Variable linear decomposition reduced significantly data dimensionality and enriched three principal factors responsible for variance of memory-related protein levels at (1) the initial phase of memory acquisition (165 proteins), (2) during the steep learning improvement (148 proteins), and (3) the final phase of the learning curve (123 proteins). Gene ontology and signaling pathways analysis revealed a clear correlation between memory improvement and learning phase-curbed expression profiles of proteins belonging to specific functional categories. We found differential enrichment of (1) neurotrophic factors signaling pathways, proteins regulating synaptic transmission, and actin microfilament during the first day of the learning curve; (2) transcription and translation machinery, protein

  4. Neuroscience of learning and memory for addiction medicine: from habit formation to memory reconsolidation.

    Science.gov (United States)

    Torregrossa, Mary M; Taylor, Jane R

    2016-01-01

    Identifying effective pharmacological treatments for addictive disorders has remained an elusive goal. Many different classes of drugs have shown some efficacy in preclinical models, but the number of effective clinical therapeutics has remained stubbornly low. The persistence of drug use and the high frequency of relapse is at least partly attributable to the enduring ability of environmental stimuli associated with drug use to maintain behavioral patterns of drug use and induce craving during abstinence. We propose that stimuli associated with drug use exert such powerful control over behavior through the development of abnormally strong memories, and their ability to initiate subconscious sequences of motor actions (habits) that promote uncontrolled drug use. In this chapter, we will review the evidence suggesting that drugs of abuse strengthen associations with cues in the environment and facilitate habit formation. We will also discuss potential mechanisms for disrupting memories associated with drug use to help improve treatments for addiction. © 2016 Elsevier B.V. All rights reserved.

  5. Differential effects of ongoing EEG beta and theta power on memory formation.

    Directory of Open Access Journals (Sweden)

    Sebastian Scholz

    Full Text Available Recently, elevated ongoing pre-stimulus beta power (13-17 Hz at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz, with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  6. Differential effects of ongoing EEG beta and theta power on memory formation.

    Science.gov (United States)

    Scholz, Sebastian; Schneider, Signe Luisa; Rose, Michael

    2017-01-01

    Recently, elevated ongoing pre-stimulus beta power (13-17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13-17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3-7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.

  7. Sleep-dependent facilitation of episodic memory details.

    Science.gov (United States)

    van der Helm, Els; Gujar, Ninad; Nishida, Masaki; Walker, Matthew P

    2011-01-01

    While a role for sleep in declarative memory processing is established, the qualitative nature of this consolidation benefit, and the physiological mechanisms mediating it, remain debated. Here, we investigate the impact of sleep physiology on characteristics of episodic memory using an item- (memory elements) and context- (contextual details associated with those elements) learning paradigm; the latter being especially dependent on the hippocampus. Following back-to-back encoding of two word lists, each associated with a different context, participants were assigned to either a Nap-group, who obtained a 120-min nap, or a No Nap-group. Six hours post-encoding, participants performed a recognition test involving item-memory and context-memory judgments. In contrast to item-memory, which demonstrated no between-group differences, a significant benefit in context-memory developed in the Nap-group, the extent of which correlated both with the amount of stage-2 NREM sleep and frontal fast sleep-spindles. Furthermore, a difference was observed on the basis of word-list order, with the sleep benefit and associated physiological correlations being selective for the second word-list, learned last (most proximal to sleep). These findings suggest that sleep may preferentially benefit contextual (hippocampal-dependent) aspects of memory, supported by sleep-spindle oscillations, and that the temporal order of initial learning differentially determines subsequent offline consolidation.

  8. Sleep-dependent facilitation of episodic memory details.

    Directory of Open Access Journals (Sweden)

    Els van der Helm

    Full Text Available While a role for sleep in declarative memory processing is established, the qualitative nature of this consolidation benefit, and the physiological mechanisms mediating it, remain debated. Here, we investigate the impact of sleep physiology on characteristics of episodic memory using an item- (memory elements and context- (contextual details associated with those elements learning paradigm; the latter being especially dependent on the hippocampus. Following back-to-back encoding of two word lists, each associated with a different context, participants were assigned to either a Nap-group, who obtained a 120-min nap, or a No Nap-group. Six hours post-encoding, participants performed a recognition test involving item-memory and context-memory judgments. In contrast to item-memory, which demonstrated no between-group differences, a significant benefit in context-memory developed in the Nap-group, the extent of which correlated both with the amount of stage-2 NREM sleep and frontal fast sleep-spindles. Furthermore, a difference was observed on the basis of word-list order, with the sleep benefit and associated physiological correlations being selective for the second word-list, learned last (most proximal to sleep. These findings suggest that sleep may preferentially benefit contextual (hippocampal-dependent aspects of memory, supported by sleep-spindle oscillations, and that the temporal order of initial learning differentially determines subsequent offline consolidation.

  9. Inhibition of histone deacetylase 3 via RGFP966 facilitates cortical plasticity underlying unusually accurate auditory associative cue memory for excitatory and inhibitory cue-reward associations.

    Science.gov (United States)

    Shang, Andrea; Bylipudi, Sooraz; Bieszczad, Kasia M

    2018-05-31

    Epigenetic mechanisms are key for regulating long-term memory (LTM) and are known to exert control on memory formation in multiple systems of the adult brain, including the sensory cortex. One epigenetic mechanism is chromatin modification by histone acetylation. Blocking the action of histone de-acetylases (HDACs) that normally negatively regulate LTM by repressing transcription, has been shown to enable memory formation. Indeed, HDAC-inhibition appears to facilitate memory by altering the dynamics of gene expression events important for memory consolidation. However less understood are the ways in which molecular-level consolidation processes alter subsequent memory to enhance storage or facilitate retrieval. Here we used a sensory perspective to investigate whether the characteristics of memory formed with HDAC inhibitors are different from naturally-formed memory. One possibility is that HDAC inhibition enables memory to form with greater sensory detail than normal. Because the auditory system undergoes learning-induced remodeling that provides substrates for sound-specific LTM, we aimed to identify behavioral effects of HDAC inhibition on memory for specific sound features using a standard model of auditory associative cue-reward learning, memory, and cortical plasticity. We found that three systemic post-training treatments of an HDAC3-inhibitor (RGPF966, Abcam Inc.) in rats in the early phase of training facilitated auditory discriminative learning, changed auditory cortical tuning, and increased the specificity for acoustic frequency formed in memory of both excitatory (S+) and inhibitory (S-) associations for at least 2 weeks. The findings support that epigenetic mechanisms act on neural and behavioral sensory acuity to increase the precision of associative cue memory, which can be revealed by studying the sensory characteristics of long-term associative memory formation with HDAC inhibitors. Published by Elsevier B.V.

  10. Facilitating influence of stress on the consolidation of fear memory induced by a weak training: reversal by midazolam pretreatment.

    Science.gov (United States)

    Maldonado, Noelia Martina; Martijena, Irene Delia; Molina, Víctor Alejandro

    2011-11-20

    It is well known that an emotionally arousing experience usually results in a robust and persistent memory trace. The present study explored the potential mechanisms involved in the influence of stress on the consolidation of a contextual fear memory in animals subjected to a weak fear training protocol, and whether pretreatment with intra-basolateral amygdala or systemic administration of midazolam (MDZ) prevents the potential stress-induced influence on fear memory formation. A previous restraint session facilitated fear retention, this effect was not due to a sensitized effect of restraint on the footshock experience. MDZ, both systemically or intra-basolateral amygdala infusion prior to the restraint, attenuated the stress-induced promoting influence on fear memory formation. In addition, stress exposure activated the ERK1/2 pathway in basolateral amygdala (BLA) after the weak training procedure but not after the immediate footshock protocol. Similar to our behavioral findings, MDZ attenuated stress-induced elevation of phospho-ERK2 (p-ERK2) in BLA following the acquisition session. Given that the activation of ERK1/2 pathway is essential for associative learning, we propose that stress-induced facilitation of p-ERK2 in BLA is an important mechanism for the promoting influence of stress on the consolidation of contextual fear memory. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Muscarinic Acetylcholine Receptors Act in Synergy to Facilitate Learning and Memory

    Science.gov (United States)

    Leaderbrand, Katherine; Chen, Helen J.; Corcoran, Kevin A.; Guedea, Anita L.; Jovasevic, Vladimir; Wess, Jurgen; Radulovic, Jelena

    2016-01-01

    Understanding how episodic memories are formed and retrieved is necessary if we are to treat disorders in which they malfunction. Muscarinic acetylcholine receptors (mAChR) in the hippocampus and cortex underlie memory formation, but there is conflicting evidence regarding their role in memory retrieval. Additionally, there is no consensus on…

  12. Histone Deacetylase Inhibition Facilitates Massed Pattern-Induced Synaptic Plasticity and Memory

    Science.gov (United States)

    Pandey, Kiran; Sharma, Kaushik P.; Sharma, Shiv K.

    2015-01-01

    Massed training is less effective for long-term memory formation than the spaced training. The role of acetylation in synaptic plasticity and memory is now well established. However, the role of this important protein modification in synaptic plasticity induced by massed pattern of stimulation or memory induced by massed training is not well…

  13. Memory formation during anaesthesia: plausibility of a neurophysiological basis

    Science.gov (United States)

    Veselis, R. A.

    2015-01-01

    As opposed to conscious, personally relevant (explicit) memories that we can recall at will, implicit (unconscious) memories are prototypical of ‘hidden’ memory; memories that exist, but that we do not know we possess. Nevertheless, our behaviour can be affected by these memories; in fact, these memories allow us to function in an ever-changing world. It is still unclear from behavioural studies whether similar memories can be formed during anaesthesia. Thus, a relevant question is whether implicit memory formation is a realistic possibility during anaesthesia, considering the underlying neurophysiology. A different conceptualization of memory taxonomy is presented, the serial parallel independent model of Tulving, which focuses on dynamic information processing with interactions among different memory systems rather than static classification of different types of memories. The neurophysiological basis for subliminal information processing is considered in the context of brain function as embodied in network interactions. Function of sensory cortices and thalamic activity during anaesthesia are reviewed. The role of sensory and perisensory cortices, in particular the auditory cortex, in support of memory function is discussed. Although improbable, with the current knowledge of neurophysiology one cannot rule out the possibility of memory formation during anaesthesia. PMID:25735711

  14. Memory formation during anaesthesia: plausibility of a neurophysiological basis.

    Science.gov (United States)

    Veselis, R A

    2015-07-01

    As opposed to conscious, personally relevant (explicit) memories that we can recall at will, implicit (unconscious) memories are prototypical of 'hidden' memory; memories that exist, but that we do not know we possess. Nevertheless, our behaviour can be affected by these memories; in fact, these memories allow us to function in an ever-changing world. It is still unclear from behavioural studies whether similar memories can be formed during anaesthesia. Thus, a relevant question is whether implicit memory formation is a realistic possibility during anaesthesia, considering the underlying neurophysiology. A different conceptualization of memory taxonomy is presented, the serial parallel independent model of Tulving, which focuses on dynamic information processing with interactions among different memory systems rather than static classification of different types of memories. The neurophysiological basis for subliminal information processing is considered in the context of brain function as embodied in network interactions. Function of sensory cortices and thalamic activity during anaesthesia are reviewed. The role of sensory and perisensory cortices, in particular the auditory cortex, in support of memory function is discussed. Although improbable, with the current knowledge of neurophysiology one cannot rule out the possibility of memory formation during anaesthesia. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    Science.gov (United States)

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

    2014-01-05

    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.

  16. Developing a hippocampal neural prosthetic to facilitate human memory encoding and recall

    Science.gov (United States)

    Hampson, Robert E.; Song, Dong; Robinson, Brian S.; Fetterhoff, Dustin; Dakos, Alexander S.; Roeder, Brent M.; She, Xiwei; Wicks, Robert T.; Witcher, Mark R.; Couture, Daniel E.; Laxton, Adrian W.; Munger-Clary, Heidi; Popli, Gautam; Sollman, Myriam J.; Whitlow, Christopher T.; Marmarelis, Vasilis Z.; Berger, Theodore W.; Deadwyler, Sam A.

    2018-06-01

    Objective. We demonstrate here the first successful implementation in humans of a proof-of-concept system for restoring and improving memory function via facilitation of memory encoding using the patient’s own hippocampal spatiotemporal neural codes for memory. Memory in humans is subject to disruption by drugs, disease and brain injury, yet previous attempts to restore or rescue memory function in humans typically involved only nonspecific, modulation of brain areas and neural systems related to memory retrieval. Approach. We have constructed a model of processes by which the hippocampus encodes memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of short-term memory. A nonlinear multi-input, multi-output (MIMO) model of hippocampal CA3 and CA1 neural firing is computed that predicts activation patterns of CA1 neurons during the encoding (sample) phase of a delayed match-to-sample (DMS) human short-term memory task. Main results. MIMO model-derived electrical stimulation delivered to the same CA1 locations during the sample phase of DMS trials facilitated short-term/working memory by 37% during the task. Longer term memory retention was also tested in the same human subjects with a delayed recognition (DR) task that utilized images from the DMS task, along with images that were not from the task. Across the subjects, the stimulated trials exhibited significant improvement (35%) in both short-term and long-term retention of visual information. Significance. These results demonstrate the facilitation of memory encoding which is an important feature for the construction of an implantable neural prosthetic to improve human memory.

  17. The roles of the actin cytoskeleton in fear memory formation

    Directory of Open Access Journals (Sweden)

    Raphael eLamprecht

    2011-07-01

    Full Text Available The formation and storage of fear memory is needed to adapt behavior and avoid danger during subsequent fearful events. However, fear memory may also play a significant role in stress and anxiety disorders. When fear becomes disproportionate to that necessary to cope with a given stimulus, or begins to occur in inappropriate situations, a fear or anxiety disorder exists. Thus, the study of cellular and molecular mechanisms underpinning fear memory may shed light on the formation of memory and on anxiety and stress related disorders. Evidence indicates that fear learning leads to changes in neuronal synaptic transmission and morphology in brain areas underlying fear memory formation including the amygdala and hippocampus. The actin cytoskeleton has been shown to participate in these key neuronal processes. Recent findings show that the actin cytoskeleton is needed for fear memory formation and extinction. Moreover, the actin cytoskeleton is involved in synaptic plasticity and in neuronal morphogenesis in brain areas that mediate fear memory. The actin cytoskeleton may therefore mediate between synaptic transmission during fear learning and long-term cellular alterations mandatory for fear memory formation.

  18. Assessment of serotonergic system in formation of memory and learning

    Directory of Open Access Journals (Sweden)

    J. C. da Silva

    2017-11-01

    Full Text Available Abstract We evaluated the involvement of the serotonergic system on memory formation and learning processes in healthy adults Wistar rats. Fifty-seven rats of 5 groups had one serotonergic nuclei damaged by an electric current. Electrolytic lesion was carried out using a continuous current of 2mA during two seconds by stereotactic surgery. Animals were submitted to learning and memory tests. Rats presented different responses in the memory tests depending on the serotonergic nucleus involved. Both explicit and implicit memory may be affected after lesion although some groups showed significant difference and others did not. A damage in the serotonergic nucleus was able to cause impairment in the memory of Wistar. The formation of implicit and explicit memory is impaired after injury in some serotonergic nuclei.

  19. Memantine facilitates memory consolidation and reconsolidation in the day-old chick.

    Science.gov (United States)

    Samartgis, Jodi R; Schachte, Leslie; Hazi, Agnes; Crowe, Simon F

    2012-05-01

    Memantine is a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist that has been approved for the treatment of the cognitive deficits noted in Alzheimer's disease. While there is a body of research that supports memantine's facilitative action upon memory compromise, this series of studies aimed to investigate the effects of this drug in healthy animals with intact memory functioning. A 0.1 mM dose of memantine injected immediately after a weakly aversive training event (i.e. 20% v/v methyl anthranilate) was found to enhance passive avoidance learning for this event in day-old chicks up to 24 h following training. The same dose of memantine was also observed to enhance memory for the training event when it was administered in conjunction with a reminder trial. These results suggest that memantine is capable of facilitating both memory consolidation as well as memory reconsolidation. It was concluded that memantine's mechanism may involve the short-term or intermediate memory phases of the Gibbs and Ng model of memory, and that the current findings represent enhancement of intact memory, rather than amelioration of memory compromise. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  20. Hormonal regulation of AMPA receptor trafficking and memory formation

    Directory of Open Access Journals (Sweden)

    Harmen J Krugers

    2009-10-01

    Full Text Available Humans and rodents retain memories for stressful events very well. The facilitated retention of these memories is normally very useful. However, in susceptible individuals a variety of pathological conditions may develop in which memories related to stressful events remain inappropriately present, such as in post-traumatic stress disorder. The memory enhancing effects of stress are mediated by hormones, such as norepinephrine and glucocorticoids which are released during stressful experiences. Here we review recently identified molecular mechanisms that underlie the effects of stress hormones on synaptic efficacy and learning and memory. We discuss AMPA receptors as major target for stress hormones and describe a model in which norepinephrine and glucocorticoids are able to strengthen and prolong different phases of stressful memories.

  1. Neuropeptide S interacts with the basolateral amygdala noradrenergic system in facilitating object recognition memory consolidation.

    Science.gov (United States)

    Han, Ren-Wen; Xu, Hong-Jiao; Zhang, Rui-San; Wang, Pei; Chang, Min; Peng, Ya-Li; Deng, Ke-Yu; Wang, Rui

    2014-01-01

    The noradrenergic activity in the basolateral amygdala (BLA) was reported to be involved in the regulation of object recognition memory. As the BLA expresses high density of receptors for Neuropeptide S (NPS), we investigated whether the BLA is involved in mediating NPS's effects on object recognition memory consolidation and whether such effects require noradrenergic activity. Intracerebroventricular infusion of NPS (1nmol) post training facilitated 24-h memory in a mouse novel object recognition task. The memory-enhancing effect of NPS could be blocked by the β-adrenoceptor antagonist propranolol. Furthermore, post-training intra-BLA infusions of NPS (0.5nmol/side) improved 24-h memory for objects, which was impaired by co-administration of propranolol (0.5μg/side). Taken together, these results indicate that NPS interacts with the BLA noradrenergic system in improving object recognition memory during consolidation. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Functional neuroanatomy of Drosophila olfactory memory formation.

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L

    2014-10-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry extending from the site(s) of acquisition to the site(s) controlling memory expression? (3) How is information processed across this circuit to consolidate early-forming, disruptable memories to stable, late memories? Much progress has been made and a few strong conclusions have emerged: (1) Acquisition occurs at multiple sites within the olfactory nervous system but is mediated predominantly by the γ mushroom body neurons. (2) The expression of long-term memory is completely dependent on the synaptic output of α/β mushroom body neurons. (3) Consolidation occurs, in part, through circuit interactions between mushroom body and dorsal paired medial neurons. Despite this progress, a complete and unified model that details the pathway from acquisition to memory expression remains elusive. © 2014 Guven-Ozkan and Davis; Published by Cold Spring Harbor Laboratory Press.

  3. Functional neuroanatomy of Drosophila olfactory memory formation

    OpenAIRE

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying Drosophila learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive and aversive reinforcers: (1) Which neurons within the olfactory nervous system mediate the acquisition of memory? (2) What is the complete neural circuitry exten...

  4. Early-life exposure to fibroblast growth factor-2 facilitates context-dependent long-term memory in developing rats.

    Science.gov (United States)

    Graham, Bronwyn M; Richardson, Rick

    2010-06-01

    Fibroblast growth factor-2 (FGF2) is a potent neurotrophic factor that is involved in brain development and the formation of long-term memory. It has recently been shown that acute FGF2, administered at the time of learning, enhances long-term memory for contextual fear conditioning as well as extinction of conditioned fear in developing rats. As other research has shown that administering FGF2 on the first day of life leads to long-term morphological changes in the hippocampus, in the present study we investigated whether early life exposure to FGF2 affects contextual fear conditioning, and renewal following extinction, later in life. Experiment 1 demonstrated that a single injection of FGF2 on Postnatal Day (PND) 1 did not lead to any detectable changes in contextual fear conditioning in PND 16 or PND 23 rats. Experiments 2 and 3 demonstrated that 5 days of injections of FGF2 (from PND 1-5) facilitated contextual fear conditioning in PND 16 and PND 23 rats. Experiment 4 demonstrated that the observed facilitation of memory was not due to FGF2 increasing rats' sensitivity to foot shock. Experiment 5 showed that early life exposure to FGF2 did not affect learning about a discrete conditioned stimulus, but did allow PND 16 rats to use contextual information in more complex ways, leading to context-dependent extinction of conditioned fear. These results further implicate FGF2 as a critical signal involved in the development of learning and memory.

  5. Memory for Lectures: How Lecture Format Impacts the Learning Experience.

    Science.gov (United States)

    Varao-Sousa, Trish L; Kingstone, Alan

    2015-01-01

    The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.

  6. Memory for Lectures: How Lecture Format Impacts the Learning Experience.

    Directory of Open Access Journals (Sweden)

    Trish L Varao-Sousa

    Full Text Available The present study investigated what impact the presentation style of a classroom lecture has on memory, mind wandering, and the subjective factors of interest and motivation. We examined if having a professor lecturing live versus on video alters the learning experience of the students in the classroom. During the lectures, students were asked to report mind wandering and later complete a memory test. The lecture format was manipulated such that all the students received two lectures, one live and one a pre-recorded video. Results indicate that lecture format affected memory performance but not mind wandering, with enhanced memory in the live lectures. Additionally, students reported greater interest and motivation in the live lectures. Given that a single change to the classroom environment, professor presence, impacted memory performance, as well as motivation and interest, the present results have several key implications for technology-based integrations into higher education classrooms.

  7. Neural and Cellular Mechanisms of Fear and Extinction Memory Formation

    Science.gov (United States)

    Orsini, Caitlin A.; Maren, Stephen

    2012-01-01

    Over the course of natural history, countless animal species have evolved adaptive behavioral systems to cope with dangerous situations and promote survival. Emotional memories are central to these defense systems because they are rapidly acquired and prepare organisms for future threat. Unfortunately, the persistence and intrusion of memories of fearful experiences are quite common and can lead to pathogenic conditions, such as anxiety and phobias. Over the course of the last thirty years, neuroscientists and psychologists alike have attempted to understand the mechanisms by which the brain encodes and maintains these aversive memories. Of equal interest, though, is the neurobiology of extinction memory formation as this may shape current therapeutic techniques. Here we review the extant literature on the neurobiology of fear and extinction memory formation, with a strong focus on the cellular and molecular mechanisms underlying these processes. PMID:22230704

  8. Ventromedial Prefrontal Cortex Activation Is Associated with Memory Formation for Predictable Rewards

    Science.gov (United States)

    Bialleck, Katharina A.; Schaal, Hans-Peter; Kranz, Thorsten A.; Fell, Juergen; Elger, Christian E.; Axmacher, Nikolai

    2011-01-01

    During reinforcement learning, dopamine release shifts from the moment of reward consumption to the time point when the reward can be predicted. Previous studies provide consistent evidence that reward-predicting cues enhance long-term memory (LTM) formation of these items via dopaminergic projections to the ventral striatum. However, it is less clear whether memory for items that do not precede a reward but are directly associated with reward consumption is also facilitated. Here, we investigated this question in an fMRI paradigm in which LTM for reward-predicting and neutral cues was compared to LTM for items presented during consumption of reliably predictable as compared to less predictable rewards. We observed activation of the ventral striatum and enhanced memory formation during reward anticipation. During processing of less predictable as compared to reliably predictable rewards, the ventral striatum was activated as well, but items associated with less predictable outcomes were remembered worse than items associated with reliably predictable outcomes. Processing of reliably predictable rewards activated the ventromedial prefrontal cortex (vmPFC), and vmPFC BOLD responses were associated with successful memory formation of these items. Taken together, these findings show that consumption of reliably predictable rewards facilitates LTM formation and is associated with activation of the vmPFC. PMID:21326612

  9. Dose-response investigation into glucose facilitation of memory performance and mood in healthy young adults.

    Science.gov (United States)

    Sünram-Lea, Sandra I; Owen, Lauren; Finnegan, Yvonne; Hu, Henglong

    2011-08-01

    It has been suggested that the memory enhancing effect of glucose follows an inverted U-shaped curve, with 25 g resulting in optimal facilitation in healthy young adults. The aim of this study was to further investigate the dose dependency of the glucose facilitation effect in this population across different memory domains and to assess moderation by interindividual differences in glucose regulation and weight. Following a double-blind, repeated measures design, 30 participants were administered drinks containing five different doses of glucose (0 g, 15 g, 25 g, 50 g, and 60 g) and were tested across a range of memory tasks. Glycaemic response and changes in mood state were assessed following drink administration. Analysis of the data showed that glucose administration did not affect mood, but significant glucose facilitation of several memory tasks was observed. However, dose-response curves differed depending on the memory task with only performance on the long-term memory tasks adhering largely to the previously observed inverted U-shaped dose-response curve. Moderation of the response profiles by interindividual differences in glucose regulation and weight was observed. The current data suggest that dose-response function and optimal dose might depend on cognitive domain and are moderated by interindividual differences in glucose regulation and weight.

  10. Functional Neuroanatomy of "Drosophila" Olfactory Memory Formation

    Science.gov (United States)

    Guven-Ozkan, Tugba; Davis, Ronald L.

    2014-01-01

    New approaches, techniques and tools invented over the last decade and a half have revolutionized the functional dissection of neural circuitry underlying "Drosophila" learning. The new methodologies have been used aggressively by researchers attempting to answer three critical questions about olfactory memories formed with appetitive…

  11. How schema and novelty augment memory formation

    NARCIS (Netherlands)

    van Kesteren, Marlieke T R; Ruiter, Dirk J; Fernández, Guillén; Henson, Richard N

    Information that is congruent with existing knowledge (a schema) is usually better remembered than less congruent information. Only recently, however, has the role of schemas in memory been studied from a systems neuroscience perspective. Moreover, incongruent (novel) information is also sometimes

  12. Characterisation of genes induced during memory formation in the chick

    International Nuclear Information System (INIS)

    Bailey, K.A.; Luermans, J.; Gibbs, M.

    2002-01-01

    Full text: Memory formation can be divided into short-term and long-term. Short-term memory involves electro-chemical activity in the neurons whereas long-term memory requires a permanent change that includes protein synthesis. One of the problems involved with identifying late memory related genes is determining an optimal system in which to study gene expression. We have used a discriminated passive avoidance task in chicks to identify genes that are differentially regulated during memory formation. A mRNA subtraction method was previously used to specifically identify several genes that are expressed in the chick intermediate medial hyperstriatum ventrale (IMHV) within two hours of training. Eight bands ranging in size from 400bp to 1100bp were obtained in the initially screen. We are currently cloning these PCR products into suitable vectors for further analysis. Two of these clones have been sequenced and analysed using both the blastn and blastx programs in ANGIS. The first clone was found to correspond to cytochrome c oxidase subunit 2. Cytochrome C oxidase (COX) is a transmembrane protein localized in the inner mitochondrial membrane and forms part of the mitochondrial respiratory chain complex. The second clone codes for the ferritin heavy chain. Ferritin is a ubiquitous protein that is involved in iron homeostasis. At present it is unclear what role these two proteins play in memory formation but further studies are being undertaken to determine the expression profiles of these genes following memory induction. Copyright (2002) Australian Neuroscience Society

  13. On the formation of collective memories: the role of a dominant narrator.

    Science.gov (United States)

    Cuc, Alexandru; Ozuru, Yasuhiro; Manier, David; Hirst, William

    2006-06-01

    To test our hypothesis that conversations can contribute to the formation of collective memory, we asked participants to study stories and to recall them individually (pregroup recollection), then as a group (group recounting), and then once again individually (postgroup recollection). One way that postgroup collective memories can be formed under these circumstances is if unshared pregroup recollections in the group recounting influences others' postgroup recollections. In the present research, we explored (using tests of recall and recognition) whether the presence of a dominant narrator can facilitate the emergence of unshared pregroup recollections in a group recounting and whether this emergence is associated with changes in postgroup recollections. We argue that the formation of a collective memory through conversation is not inevitable but is limited by cognitive factors, such as conditions for social contagion, and by situational factors, such as the presence of a narrator.

  14. Working memory binding and episodic memory formation in aging, mild cognitive impairment, and Alzheimer's dementia

    NARCIS (Netherlands)

    Geldorp, B. van; Heringa, S.M.; Berg, E. van den; Olde Rikkert, M.G.M.; Biessels, G.J.; Kessels, R.P.C.

    2015-01-01

    INTRODUCTION: Recent studies indicate that in both normal and pathological aging working memory (WM) performance deteriorates, especially when associations have to be maintained. However, most studies typically do not assess the relationship between WM and episodic memory formation. In the present

  15. Novelty-Sensitive Dopaminergic Neurons in the Human Substantia Nigra Predict Success of Declarative Memory Formation.

    Science.gov (United States)

    Kamiński, Jan; Mamelak, Adam N; Birch, Kurtis; Mosher, Clayton P; Tagliati, Michele; Rutishauser, Ueli

    2018-04-12

    The encoding of information into long-term declarative memory is facilitated by dopamine. This process depends on hippocampal novelty signals, but it remains unknown how midbrain dopaminergic neurons are modulated by declarative-memory-based information. We recorded individual substantia nigra (SN) neurons and cortical field potentials in human patients performing a recognition memory task. We found that 25% of SN neurons were modulated by stimulus novelty. Extracellular waveform shape and anatomical location indicated that these memory-selective neurons were putatively dopaminergic. The responses of memory-selective neurons appeared 527 ms after stimulus onset, changed after a single trial, and were indicative of recognition accuracy. SN neurons phase locked to frontal cortical theta-frequency oscillations, and the extent of this coordination predicted successful memory formation. These data reveal that dopaminergic neurons in the human SN are modulated by memory signals and demonstrate a progression of information flow in the hippocampal-basal ganglia-frontal cortex loop for memory encoding. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

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

    Science.gov (United States)

    Alonso, Mariana; Bekinschtein, Pedro; Cammarota, Martín; Vianna, Monica R M; Izquierdo, Iván; Medina, Jorge H

    2005-01-01

    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 plasticity in hippocampal and cortical neurons. We have recently demonstrated that endogenous BDNF in the hippocampus is involved in memory formation. Here we examined the role of BDNF in the parietal cortex (PCx) in short-term (STM) and long-term memory (LTM) formation of a one-trial fear-motivated learning task in rats. Bilateral infusions of function-blocking anti-BDNF antibody into the PCx impaired both STM and LTM retention scores and decreased the phosphorylation state of cAMP response element-binding protein (CREB). In contrast, intracortical administration of recombinant human BDNF facilitated LTM and increased CREB activation. Moreover, inhibitory avoidance training is associated with a rapid and transient increase in phospho-CREB/total CREB ratio in the PCx. Thus, our results indicate that endogenous BDNF is required for both STM and LTM formation of inhibitory avoidance learning, possibly involving CREB activation-dependent mechanisms. The present data support the idea that early sensory areas constitute important components of the networks subserving memory formation and that information processing in neocortex plays an important role in memory formation.

  17. Stable panoramic views facilitate snap-shot like memories for spatial reorientation in homing pigeons.

    Directory of Open Access Journals (Sweden)

    Tommaso Pecchia

    Full Text Available Following spatial disorientation, animals can reorient themselves by relying on geometric cues (metric and sense specified both by the macroscopic surface layout of an enclosed space and prominent visual landmarks in arrays. Whether spatial reorientation in arrays of landmarks is based on explicit representation of the geometric cues is a matter of debate. Here we trained homing pigeons (Columba livia to locate a food-reward in a rectangular array of four identical or differently coloured pipes provided with four openings, only one of which allowed the birds to have access to the reward. Pigeons were trained either with a stable or a variable position of the opening on pipes, so that they could view the array either from the same or a variable perspective. Explicit mapping of configural geometry would predict successful reorientation irrespective of access condition. In contrast, we found that a stable view of the array facilitated spatial learning in homing pigeons, likely through the formation of snapshot-like memories.

  18. Interregional synaptic maps among engram cells underlie memory formation.

    Science.gov (United States)

    Choi, Jun-Hyeok; Sim, Su-Eon; Kim, Ji-Il; Choi, Dong Il; Oh, Jihae; Ye, Sanghyun; Lee, Jaehyun; Kim, TaeHyun; Ko, Hyoung-Gon; Lim, Chae-Seok; Kaang, Bong-Kiun

    2018-04-27

    Memory resides in engram cells distributed across the brain. However, the site-specific substrate within these engram cells remains theoretical, even though it is generally accepted that synaptic plasticity encodes memories. We developed the dual-eGRASP (green fluorescent protein reconstitution across synaptic partners) technique to examine synapses between engram cells to identify the specific neuronal site for memory storage. We found an increased number and size of spines on CA1 engram cells receiving input from CA3 engram cells. In contextual fear conditioning, this enhanced connectivity between engram cells encoded memory strength. CA3 engram to CA1 engram projections strongly occluded long-term potentiation. These results indicate that enhanced structural and functional connectivity between engram cells across two directly connected brain regions forms the synaptic correlate for memory formation. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  19. Synaptic clustering within dendrites: an emerging theory of memory formation

    Science.gov (United States)

    Kastellakis, George; Cai, Denise J.; Mednick, Sara C.; Silva, Alcino J.; Poirazi, Panayiota

    2015-01-01

    It is generally accepted that complex memories are stored in distributed representations throughout the brain, however the mechanisms underlying these representations are not understood. Here, we review recent findings regarding the subcellular mechanisms implicated in memory formation, which provide evidence for a dendrite-centered theory of memory. Plasticity-related phenomena which affect synaptic properties, such as synaptic tagging and capture, synaptic clustering, branch strength potentiation and spinogenesis provide the foundation for a model of memory storage that relies heavily on processes operating at the dendrite level. The emerging picture suggests that clusters of functionally related synapses may serve as key computational and memory storage units in the brain. We discuss both experimental evidence and theoretical models that support this hypothesis and explore its advantages for neuronal function. PMID:25576663

  20. Facilitating participation in formative evaluation supported by effect map

    DEFF Research Database (Denmark)

    Granlien, Maren Sander

    2009-01-01

    It has been suggested that formative evaluation should be an integrated part of system implementation in order to improve the outcome of system use. In a design project an approach combining participatory design (PD) and formative evaluation has shown a great potential for improving the design of...... map is applied in an action research study in the Danish health care sector aiming at improving the medication process and the use of the electronic medication record supporting the medication process. ...... designed effect map. The purpose of the effect map is twofold: a) To encourage user participation in the early activities of formative evaluation b) The effects specified can be used as formative evaluation measures and guidance in the process of improving the system. The evaluation approach and the effect...

  1. Targeted memory reactivation during slow wave sleep facilitates emotional memory consolidation.

    Science.gov (United States)

    Cairney, Scott A; Durrant, Simon J; Hulleman, Johan; Lewis, Penelope A

    2014-04-01

    To investigate the mechanisms by which auditory targeted memory reactivation (TMR) during slow wave sleep (SWS) influences the consolidation of emotionally negative and neutral memories. Each of 72 (36 negative, 36 neutral) picture-location associations were encoded with a semantically related sound. During a subsequent nap, half of the sounds were replayed in SWS, before picture-location recall was examined in a final test. Manchester Sleep Laboratory, University of Manchester. 15 adults (3 male) mean age = 20.40 (standard deviation ± 3.07). TMR with auditory cues during SWS. Performance was assessed by memory accuracy and recall response times (RTs). Data were analyzed with a 2 (sound: replayed/not replayed) × 2 (emotion: negative/neutral) repeated measures analysis of covariance with SWS duration, and then SWS spindles, as the mean-centered covariate. Both analyses revealed a significant three-way interaction for RTs but not memory accuracy. Critically, SWS duration and SWS spindles predicted faster memory judgments for negative, relative to neutral, picture locations that were cued with TMR. TMR initiates an enhanced consolidation process during subsequent SWS, wherein sleep spindles mediate the selective enhancement of reactivated emotional memories.

  2. Seeing Iconic Gestures While Encoding Events Facilitates Children's Memory of These Events.

    Science.gov (United States)

    Aussems, Suzanne; Kita, Sotaro

    2017-11-08

    An experiment with 72 three-year-olds investigated whether encoding events while seeing iconic gestures boosts children's memory representation of these events. The events, shown in videos of actors moving in an unusual manner, were presented with either iconic gestures depicting how the actors performed these actions, interactive gestures, or no gesture. In a recognition memory task, children in the iconic gesture condition remembered actors and actions better than children in the control conditions. Iconic gestures were categorized based on how much of the actors was represented by the hands (feet, legs, or body). Only iconic hand-as-body gestures boosted actor memory. Thus, seeing iconic gestures while encoding events facilitates children's memory of those aspects of events that are schematically highlighted by gesture. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  3. Coexistence facilitates interspecific biofilm formation in complex microbial communities

    DEFF Research Database (Denmark)

    Madsen, Jonas Stenløkke; Røder, Henriette Lyng; Russel, Jakob

    2016-01-01

    Social interactions in which bacteria respond to one another by modifying their phenotype are central determinants of microbial communities. It is known that interspecific interactions influence the biofilm phenotype of bacteria; a phenotype that is central to the fitness of bacteria. However......, the underlying role of fundamental ecological factors, specifically coexistence and phylogenetic history, in biofilm formation remains unclear. This study examines how social interactions affect biofilm formation in multi-species co-cultures from five diverse environments. We found prevalence of increased...

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

    International Nuclear Information System (INIS)

    Hou Qiuling; Gao Xiang; Lu Qi; Zhang Xuehan; Tu Yanyang; Jin Meilei; Zhao Guoping; Yu Lei; Jing Naihe; Li Baoming

    2006-01-01

    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

  5. BAF53b, a Neuron-Specific Nucleosome Remodeling Factor, Is Induced after Learning and Facilitates Long-Term Memory Consolidation.

    Science.gov (United States)

    Yoo, Miran; Choi, Kwang-Yeon; Kim, Jieun; Kim, Mujun; Shim, Jaehoon; Choi, Jun-Hyeok; Cho, Hye-Yeon; Oh, Jung-Pyo; Kim, Hyung-Su; Kaang, Bong-Kiun; Han, Jin-Hee

    2017-03-29

    Although epigenetic mechanisms of gene expression regulation have recently been implicated in memory consolidation and persistence, the role of nucleosome-remodeling is largely unexplored. Recent studies show that the functional loss of BAF53b, a postmitotic neuron-specific subunit of the BAF nucleosome-remodeling complex, results in the deficit of consolidation of hippocampus-dependent memory and cocaine-associated memory in the rodent brain. However, it is unclear whether BAF53b expression is regulated during memory formation and how BAF53b regulates fear memory in the amygdala, a key brain site for fear memory encoding and storage. To address these questions, we used viral vector approaches to either decrease or increase BAF53b function specifically in the lateral amygdala of adult mice in auditory fear conditioning paradigm. Knockdown of Baf53b before training disrupted long-term memory formation with no effect on short-term memory, basal synaptic transmission, and spine structures. We observed in our qPCR analysis that BAF53b was induced in the lateral amygdala neurons at the late consolidation phase after fear conditioning. Moreover, transient BAF53b overexpression led to persistently enhanced memory formation, which was accompanied by increase in thin-type spine density. Together, our results provide the evidence that BAF53b is induced after learning, and show that such increase of BAF53b level facilitates memory consolidation likely by regulating learning-related spine structural plasticity. SIGNIFICANCE STATEMENT Recent works in the rodent brain begin to link nucleosome remodeling-dependent epigenetic mechanism to memory consolidation. Here we show that BAF53b, an epigenetic factor involved in nucleosome remodeling, is induced in the lateral amygdala neurons at the late phase of consolidation after fear conditioning. Using specific gene knockdown or overexpression approaches, we identify the critical role of BAF53b in the lateral amygdala neurons for

  6. How schema and novelty augment memory formation.

    Science.gov (United States)

    van Kesteren, Marlieke T R; Ruiter, Dirk J; Fernández, Guillén; Henson, Richard N

    2012-04-01

    Information that is congruent with existing knowledge (a schema) is usually better remembered than less congruent information. Only recently, however, has the role of schemas in memory been studied from a systems neuroscience perspective. Moreover, incongruent (novel) information is also sometimes better remembered. Here, we review lesion and neuroimaging findings in animals and humans that relate to this apparent paradoxical relationship between schema and novelty. In addition, we sketch a framework relating key brain regions in medial temporal lobe (MTL) and medial prefrontal cortex (mPFC) during encoding, consolidation and retrieval of information as a function of its congruency with existing information represented in neocortex. An important aspect of this framework is the efficiency of learning enabled by congruency-dependent MTL-mPFC interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. The Formation and Extinction of Fear Memory in Tree Shrews

    Directory of Open Access Journals (Sweden)

    Shujiang eShang

    2015-07-01

    Full Text Available Fear is an emotion that is well studied due to its importance for animal survival. Experimental animals, such as rats and mice, have been widely used to model fear. However, higher animals such as nonhuman primates have rarely been used to study fear due to ethical issues and high costs. Tree shrews are small mammals that are closely related to primates; they have been used to model human-related psychosocial conditions such as stress and alcohol tolerance. Here, we describe an experimental paradigm to study the formation and extinction of fear memory in tree shrews. We designed an experimental apparatus of a light/dark box with a voltage foot shock. We found that tree shrews preferred staying in the dark box in the daytime without stimulation and showed avoidance to voltage shocks applied to the footplate in a voltage-dependent manner. Foot shocks applied to the dark box for 5 days (10 minutes per day effectively reversed the light–dark preference of the tree shrews, and this memory lasted for more than 50 days without any sign of memory decay (extinction in the absence of further stimulation. However, this fear memory was reversed with 4 days of reverse training by applying the same stimulus to the light box. When reducing the stimulus intensity during the training period, a memory extinction and subsequently reinstatement effects were observed. Thus, our results describe an efficient method of monitoring fear memory formation and extinction in tree shrews.

  8. Wnt Signaling Is Required for Long-Term Memory Formation

    Directory of Open Access Journals (Sweden)

    Ying Tan

    2013-09-01

    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 β-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 β-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.

  9. Memory for biopsychology material presented in comic book format.

    OpenAIRE

    Aleixo, Paul; Sumner, Krystina

    2017-01-01

    This study investigated the influence of format of presentation on memory for undergraduate level Biopsychology material. Ninety participants read either seven comic book pages from Aleixo and Baillon (2008) explaining the rudiments of sleep, the same material presented in text only format or seven pages where the original images were replaced with random incongruous images. Participants were tested on the material using ten multiple-choice questions. Results showed significantly higher memor...

  10. Age differences and format effects in working memory.

    Science.gov (United States)

    Foos, Paul W; Goolkasian, Paula

    2010-07-01

    Format effects refer to lower recall of printed words from working memory when compared to spoken words or pictures. These effects have been attributed to an attenuation of attention to printed words. The present experiment compares younger and older adults' recall of three or six items presented as pictures, spoken words, printed words, and alternating case WoRdS. The latter stimuli have been shown to increase attention to printed words and, thus, reduce format effects. The question of interest was whether these stimuli would also reduce format effects for older adults whose working memory capacity has fewer attentional resources to allocate. Results showed that older adults performed as well as younger adults with three items but less well with six and that format effects were reduced for both age groups, but more for young, when alternating case words were used. Other findings regarding executive control of working memory are discussed. The obtained differences support models of reduced capacity in older adult working memory.

  11. Roles of calcium/calmodulin-dependent kinase II in long-term memory formation in crickets.

    Directory of Open Access Journals (Sweden)

    Makoto Mizunami

    Full Text Available Ca(2+/calmodulin (CaM-dependent protein kinase II (CaMKII is a key molecule in many systems of learning and memory in vertebrates, but roles of CaMKII in invertebrates have not been characterized in detail. We have suggested that serial activation of NO/cGMP signaling, cyclic nucleotide-gated channel, Ca(2+/CaM and cAMP signaling participates in long-term memory (LTM formation in olfactory conditioning in crickets, and here we show participation of CaMKII in LTM formation and propose its site of action in the biochemical cascades. Crickets subjected to 3-trial conditioning to associate an odor with reward exhibited memory that lasts for a few days, which is characterized as protein synthesis-dependent LTM. In contrast, animals subjected to 1-trial conditioning exhibited memory that lasts for only several hours (mid-term memory, MTM. Injection of a CaMKII inhibitor prior to 3-trial conditioning impaired 1-day memory retention but not 1-hour memory retention, suggesting that CaMKII participates in LTM formation but not in MTM formation. Animals injected with a cGMP analogue, calcium ionophore or cAMP analogue prior to 1-trial conditioning exhibited 1-day retention, and co-injection of a CaMKII inhibitor impaired induction of LTM by the cGMP analogue or that by the calcium ionophore but not that by the cAMP analogue, suggesting that CaMKII is downstream of cGMP production and Ca(2+ influx and upstream of cAMP production in biochemical cascades for LTM formation. Animals injected with an adenylyl cyclase (AC activator prior to 1-trial conditioning exhibited 1-day retention. Interestingly, a CaMKII inhibitor impaired LTM induction by the AC activator, although AC is expected to be a downstream target of CaMKII. The results suggest that CaMKII interacts with AC to facilitate cAMP production for LTM formation. We propose that CaMKII serves as a key molecule for interplay between Ca(2+ signaling and cAMP signaling for LTM formation, a new role of Ca

  12. Hippocampal Cortactin Levels are Reduced Following Spatial Working Memory Formation, an Effect Blocked by Chronic Calpain Inhibition.

    Science.gov (United States)

    Olson, Mikel L; Ingebretson, Anna E; Harmelink, Katherine M

    2015-06-19

    The mechanism by which the hippocampus facilitates declarative memory formation appears to involve, among other things, restructuring of the actin cytoskeleton within neuronal dendrites. One protein involved in this process is cortactin, which is an important link between extracellular signaling and cytoskeletal reorganization. In this paper, we demonstrate that total hippocampal cortactin, as well as Y421-phosphorylated cortactin are transiently reduced following spatial working memory formation in the radial arm maze (RAM). Because cortactin is a substrate of the cysteine protease calpain, we also assessed the effect of chronic calpain inhibition on RAM performance and cortactin expression. Calpain inhibition impaired spatial working memory and blocked the reduction in hippocampal cortactin levels following RAM training. These findings add to a growing body of research implicating cortactin and calpain in hippocampus-dependent memory formation.

  13. Hippocampal Cortactin Levels are Reduced Following Spatial Working Memory Formation, an Effect Blocked by Chronic Calpain Inhibition

    Directory of Open Access Journals (Sweden)

    Mikel L. Olson

    2015-06-01

    Full Text Available The mechanism by which the hippocampus facilitates declarative memory formation appears to involve, among other things, restructuring of the actin cytoskeleton within neuronal dendrites. One protein involved in this process is cortactin, which is an important link between extracellular signaling and cytoskeletal reorganization. In this paper, we demonstrate that total hippocampal cortactin, as well as Y421-phosphorylated cortactin are transiently reduced following spatial working memory formation in the radial arm maze (RAM. Because cortactin is a substrate of the cysteine protease calpain, we also assessed the effect of chronic calpain inhibition on RAM performance and cortactin expression. Calpain inhibition impaired spatial working memory and blocked the reduction in hippocampal cortactin levels following RAM training. These findings add to a growing body of research implicating cortactin and calpain in hippocampus-dependent memory formation.

  14. HSPB1 facilitates the formation of non-centrosomal microtubules.

    Directory of Open Access Journals (Sweden)

    Leonardo Almeida-Souza

    Full Text Available The remodeling capacity of microtubules (MT is essential for their proper function. In mammals, MTs are predominantly formed at the centrosome, but can also originate from non-centrosomal sites, a process that is still poorly understood. We here show that the small heat shock protein HSPB1 plays a role in the control of non-centrosomal MT formation. The HSPB1 expression level regulates the balance between centrosomal and non-centrosomal MTs. The HSPB1 protein can be detected specifically at sites of de novo forming non-centrosomal MTs, while it is absent from the centrosomes. In addition, we show that HSPB1 binds preferentially to the lattice of newly formed MTs in vitro, suggesting that its function occurs by stabilizing MT seeds. Our findings open new avenues for the understanding of the role of HSPB1 in the development, maintenance and protection of cells with specialized non-centrosomal MT arrays.

  15. Cellular activation of hypothalamic hypocretin/orexin neurons facilitates short-term spatial memory in mice.

    Science.gov (United States)

    Aitta-Aho, Teemu; Pappa, Elpiniki; Burdakov, Denis; Apergis-Schoute, John

    2016-12-01

    The hypothalamic hypocretin/orexin (HO) system holds a central role in the regulation of several physiological functions critical for food-seeking behavior including mnemonic processes for effective foraging behavior. It is unclear however whether physiological increases in HO neuronal activity can support such processes. Using a designer rM3Ds receptor activation approach increasing HO neuronal activity resulted in improved short-term memory for novel locations. When tested on a non-spatial novelty object recognition task no significant difference was detected between groups indicating that hypothalamic HO neuronal activation can selectively facilitate short-term spatial memory for potentially supporting memory for locations during active exploration. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Regulation of Memory Formation by the Transcription Factor XBP1

    Directory of Open Access Journals (Sweden)

    Gabriela Martínez

    2016-02-01

    Full Text Available Contextual memory formation relies on the induction of new genes in the hippocampus. A polymorphism in the promoter of the transcription factor XBP1 was identified as a risk factor for Alzheimer’s disease and bipolar disorders. XBP1 is a major regulator of the unfolded protein response (UPR, mediating adaptation to endoplasmic reticulum (ER stress. Using a phenotypic screen, we uncovered an unexpected function of XBP1 in cognition and behavior. Mice lacking XBP1 in the nervous system showed specific impairment of contextual memory formation and long-term potentiation (LTP, whereas neuronal XBP1s overexpression improved performance in memory tasks. Gene expression analysis revealed that XBP1 regulates a group of memory-related genes, highlighting brain-derived neurotrophic factor (BDNF, a key component in memory consolidation. Overexpression of BDNF in the hippocampus reversed the XBP1-deficient phenotype. Our study revealed an unanticipated function of XBP1 in cognitive processes that is apparently unrelated to its role in ER stress.

  17. Consensus: "Can tDCS and TMS enhance motor learning and memory formation?"

    Science.gov (United States)

    Reis, Janine; Robertson, Edwin; Krakauer, John W; Rothwell, John; Marshall, Lisa; Gerloff, Christian; Wassermann, Eric; Pascual-Leone, Alvaro; Hummel, Friedhelm; Celnik, Pablo A; Classen, Joseph; Floel, Agnes; Ziemann, Ulf; Paulus, Walter; Siebner, Hartwig R; Born, Jan; Cohen, Leonardo G

    2008-10-01

    Noninvasive brain stimulation has developed as a promising tool for cognitive neuroscientists. Transcranial magnetic (TMS) and direct current (tDCS) stimulation allow researchers to purposefully enhance or decrease excitability in focal areas of the brain. The purpose of this paper is to review information on the use of TMS and tDCS as research tools to facilitate motor memory formation, motor performance and motor learning in healthy volunteers. Studies implemented so far have mostly focused on the ability of TMS and tDCS to elicit relatively short lasting motor improvements and the mechanisms underlying these changes have been only partially investigated. Despite limitations including the scarcity of data, work that has been already accomplished raises the exciting hypothesis that currently available noninvasive transcranial stimulation techniques could modulate motor learning and memory formation in healthy humans and potentially in patients with neurological and psychiatric disorders.

  18. Working memory binding and episodic memory formation in aging, mild cognitive impairment, and Alzheimer's dementia.

    Science.gov (United States)

    van Geldorp, Bonnie; Heringa, Sophie M; van den Berg, Esther; Olde Rikkert, Marcel G M; Biessels, Geert Jan; Kessels, Roy P C

    2015-01-01

    Recent studies indicate that in both normal and pathological aging working memory (WM) performance deteriorates, especially when associations have to be maintained. However, most studies typically do not assess the relationship between WM and episodic memory formation. In the present study, we examined WM and episodic memory formation in normal aging and in patients with early Alzheimer's disease (mild cognitive impairment, MCI; and Alzheimer's dementia, AD). In the first study, 26 young adults (mean age 29.6 years) were compared to 18 middle-aged adults (mean age 52.2 years) and 25 older adults (mean age 72.8 years). We used an associative delayed-match-to-sample WM task, which requires participants to maintain two pairs of faces and houses presented on a computer screen for short (3 s) or long (6 s) maintenance intervals. After the WM task, an unexpected subsequent associative memory task was administered (two-alternative forced choice). In the second study, 27 patients with AD and 19 patients with MCI were compared to 25 older controls, using the same paradigm as that in Experiment 1. Older adults performed worse than both middle-aged and young adults. No effect of delay was observed in the healthy adults, and pairs that were processed during long maintenance intervals were not better remembered in the subsequent memory task. In the MCI and AD patients, longer maintenance intervals hampered the task performance. Also, both patient groups performed significantly worse than controls on the episodic memory task as well as the associative WM task. Aging and AD present with a decline in WM binding, a finding that extends similar results in episodic memory. Longer delays in the WM task did not affect episodic memory formation. We conclude that WM deficits are found when WM capacity is exceeded, which may occur during associative processing.

  19. Olfactory memory formation in Drosophila: from molecular to systems neuroscience.

    Science.gov (United States)

    Davis, Ronald L

    2005-01-01

    The olfactory nervous system of insects and mammals exhibits many similarities, which suggests that the mechanisms for olfactory learning may be shared. Molecular genetic investigations of Drosophila learning have uncovered numerous genes whose gene products are essential for olfactory memory formation. Recent studies of the products of these genes have continued to expand the range of molecular processes known to underlie memory formation. Recent research has also broadened the neuroanatomical areas thought to mediate olfactory learning to include the antennal lobes in addition to a previously accepted and central role for the mushroom bodies. The roles for neurons extrinsic to the mushroom body neurons are becoming better defined. Finally, the genes identified to participate in Drosophila olfactory learning have conserved roles in mammalian organisms, highlighting the value of Drosophila for gene discovery.

  20. Contextual consistency facilitates long-term memory of perceptual detail in barely seen images.

    Science.gov (United States)

    Gronau, Nurit; Shachar, Meytal

    2015-08-01

    It is long known that contextual information affects memory for an object's identity (e.g., its basic level category), yet it is unclear whether schematic knowledge additionally enhances memory for the precise visual appearance of an item. Here we investigated memory for visual detail of merely glimpsed objects. Participants viewed pairs of contextually related and unrelated stimuli, presented for an extremely brief duration (24 ms, masked). They then performed a forced-choice memory-recognition test for the precise perceptual appearance of 1 of 2 objects within each pair (i.e., the "memory-target" item). In 3 experiments, we show that memory-target stimuli originally appearing within contextually related pairs are remembered better than targets appearing within unrelated pairs. These effects are obtained whether the target is presented at test with its counterpart pair object (i.e., when reiterating the original context at encoding) or whether the target is presented alone, implying that the contextual consistency effects are mediated predominantly by processes occurring during stimulus encoding, rather than during stimulus retrieval. Furthermore, visual detail encoding is improved whether object relations involve implied action or not, suggesting that, contrary to some prior suggestions, action is not a necessary component for object-to-object associative "grouping" processes. Our findings suggest that during a brief glimpse, but not under long viewing conditions, contextual associations may play a critical role in reducing stimulus competition for attention selection and in facilitating rapid encoding of sensory details. Theoretical implications with respect to classic frame theories are discussed. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  1. Molecular signals into the insular cortex and amygdala during aversive gustatory memory formation.

    Science.gov (United States)

    Bermúdez-Rattoni, Federico; Ramírez-Lugo, Leticia; Gutiérrez, Ranier; Miranda, María Isabel

    2004-02-01

    In this paper, we will provide evidence of the putative molecular signals and biochemical events that mediate the formation of long-lasting gustatory memory trace. When an animal drinks a novel taste (the conditioned stimulus; CS) and it is later associated with malaise (unconditioned stimulus; US), the animal will reject it in the next presentation, developing a long-lasting taste aversion, i.e., the taste cue becomes an aversive signal, and this is referred to as conditioning taste aversion. Different evidence indicates that the novel stimulus (taste) induces a rapid and strong cortical acetylcholine activity that decreases when the stimulus becomes familiar after several presentations. Cholinergic activation via muscarinic receptors initiates a series of intracellular events leading to plastic changes that could be related to short- and/or long-term memory gustatory trace. Such plastic changes facilitate the incoming US signals carried out by, in part, the glutamate release induced by the US. Altogether, these events could produce the cellular changes related to the switch from safe to aversive taste memory trace. A proposed working model to explain the biochemical sequence of signals during taste memory formation will be discussed.

  2. Epigenetic mechanisms in experience-driven memory formation and behavior

    Science.gov (United States)

    Puckett, Rosemary E; Lubin, Farah D

    2011-01-01

    Epigenetic mechanisms have long been associated with the regulation of gene-expression changes accompanying normal neuronal development and cellular differentiation; however, until recently these mechanisms were believed to be statically quiet in the adult brain. Behavioral neuroscientists have now begun to investigate these epigenetic mechanisms as potential regulators of gene-transcription changes in the CNS subserving synaptic plasticity and long-term memory (LTM) formation. Experimental evidence from learning and memory animal models has demonstrated that active chromatin remodeling occurs in terminally differentiated postmitotic neurons, suggesting that these molecular processes are indeed intimately involved in several stages of LTM formation, including consolidation, reconsolidation and extinction. Such chromatin modifications include the phosphorylation, acetylation and methylation of histone proteins and the methylation of associated DNA to subsequently affect transcriptional gene readout triggered by learning. The present article examines how such learning-induced epigenetic changes contribute to LTM formation and influence behavior. In particular, this article is a survey of the specific epigenetic mechanisms that have been demonstrated to regulate gene expression for both transcription factors and growth factors in the CNS, which are critical for LTM formation and storage, as well as how aberrant epigenetic processing can contribute to psychological states such as schizophrenia and drug addiction. Together, the findings highlighted in this article support a novel role for epigenetic mechanisms in the adult CNS serving as potential key molecular regulators of gene-transcription changes necessary for LTM formation and adult behavior. PMID:22126252

  3. Posttraining handling facilitates memory for auditory-cue fear conditioning in rats.

    Science.gov (United States)

    Hui, Isabel R; Hui, Gabriel K; Roozendaal, Benno; McGaugh, James L; Weinberger, Norman M

    2006-09-01

    A large number of studies have indicated that stress exposure or the administration of stress hormones and other neuroactive drugs immediately after a learning experience modulates the consolidation of long-term memory. However, there has been little investigation into how arousal induced by handling of the animals in order to administer these drugs affects memory. Therefore, the present study examined whether the posttraining injection or handling procedure per se affects memory of auditory-cue classical fear conditioning. Male Sprague-Dawley rats, which had been pre-handled on three days for 1 min each prior to conditioning, received three pairings of a single-frequency auditory stimulus and footshock, followed immediately by either a subcutaneous injection of a vehicle solution or brief handling without injection. A control group was placed back into their home cages without receiving any posttraining treatment. Retention was tested 24 h later in a novel chamber and suppression of ongoing motor behavior during a 10-s presentation of the auditory-cue served as the measure of conditioned fear. Animals that received posttraining injection or handling did not differ from each other but showed significantly less stimulus-induced movement compared to the non-handled control group. These findings thus indicate that the posttraining injection or handling procedure is sufficiently arousing or stressful to facilitate memory consolidation of auditory-cue classical fear conditioning.

  4. Tactile Ranschburg effects: facilitation and inhibitory repetition effects analogous to verbal memory.

    Science.gov (United States)

    Roe, Daisy; Miles, Christopher; Johnson, Andrew J

    2017-07-01

    The present paper examines the effect of within-sequence item repetitions in tactile order memory. Employing an immediate serial recall procedure, participants reconstructed a six-item sequence tapped upon their fingers by moving those fingers in the order of original stimulation. In Experiment 1a, within-sequence repetition of an item separated by two-intervening items resulted in a significant reduction in recall accuracy for that repeated item (i.e., the Ranschburg effect). In Experiment 1b, within-sequence repetition of an adjacent item resulted in significant recall facilitation for that repeated item. These effects mirror those reported for verbal stimuli (e.g., Henson, 1998a . Item repetition in short-term memory: Ranschburg repeated. Journal of Experimental Psychology: Learning, Memory, and Cognition, 24(5), 1162-1181. doi:doi.org/10.1037/0278-7393.24.5.1162). These data are the first to demonstrate the Ranschburg effect with non-verbal stimuli and suggest further cross-modal similarities in order memory.

  5. Working Memory Capacity and Its Relation to Stroop Interference and Facilitation Effects in Individuals with Mild Cognitive Impairment

    Science.gov (United States)

    Sung, Jee Eun; Kim, Jin Hee; Jeong, Jee Hyang; Kang, Heejin

    2012-01-01

    Purpose: The purposes of the study were to investigate (a) the task-specific differences in short-term memory (STM) and working memory capacity (WMC) in individuals with mild cognitive impairment (MCI) and normal elderly adults (NEAs), (b) the Stroop interference and facilitation effects, and (c) the relationship of STM and WMC to the Stroop…

  6. Dynamics of dendritic spines in the mouse auditory cortex during memory formation and memory recall.

    Science.gov (United States)

    Moczulska, Kaja Ewa; Tinter-Thiede, Juliane; Peter, Manuel; Ushakova, Lyubov; Wernle, Tanja; Bathellier, Brice; Rumpel, Simon

    2013-11-05

    Long-lasting changes in synaptic connections induced by relevant experiences are believed to represent the physical correlate of memories. Here, we combined chronic in vivo two-photon imaging of dendritic spines with auditory-cued classical conditioning to test if the formation of a fear memory is associated with structural changes of synapses in the mouse auditory cortex. We find that paired conditioning and unpaired conditioning induce a transient increase in spine formation or spine elimination, respectively. A fraction of spines formed during paired conditioning persists and leaves a long-lasting trace in the network. Memory recall triggered by the reexposure of mice to the sound cue did not lead to changes in spine dynamics. Our findings provide a synaptic mechanism for plasticity in sound responses of auditory cortex neurons induced by auditory-cued fear conditioning; they also show that retrieval of an auditory fear memory does not lead to a recapitulation of structural plasticity in the auditory cortex as observed during initial memory consolidation.

  7. The neurokinin-3 receptor agonist senktide facilitates the integration of memories for object, place and temporal order into episodic memory.

    Science.gov (United States)

    Chao, Owen Y; Nikolaus, Susanne; Huston, Joseph P; de Souza Silva, Maria A

    2014-10-01

    Senktide, a potent neurokinin-3 receptor (NK3-R) agonist, has been shown to have promnestic effects in adult and aged rodents and to facilitate episodic-like memory (ELM) in mice when administrated before the learning trial. In the present study we assessed the effects of senktide on memory consolidation by administering it post-trial (after the learning trial) in adult rats. We applied an ELM test, based on the integrated memory for object, place and temporal order, which we developed (Kart-Teke, de Souza Silva, Huston, & Dere, 2006). This test involves two learning trials and one test trial. We examined intervals of 1h and 23 h between the learning and test trials (experiment 1) in untreated animals and found that they exhibited intact ELM after a delay of 1 h, but not 23 h. In another test for ELM performed 7 days later, vehicle or senktide (0.2 mg/kg, s.c.) was applied immediately after the second learning trial and the test was conducted 23 h later (experiment 2). Senktide treatment recovered components of ELM (memory for place and object) compared with vehicle-treated animals. After one more week, vehicle or senktide (0.2 mg/kg, s.c.) was applied post-trial and the test conducted 6h later (experiment 3). The senktide-treated group exhibited intact ELM, unlike the vehicle-treated group. Finally, animals received post-trial treatment with either vehicle or SR142801, a selective NK3-R antagonist (6 mg/kg, i.p.), 1 min before senktide injection (0.2 mg/kg, s.c.) in the ELM paradigm and were tested 6h later (experiment 4). The vehicle+senktide group showed intact ELM, while the SR142801+senktide group did not. The results indicate that senktide facilitated the consolidation or the expression of ELM and that the senktide effect was NK3-R dependent. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Cognitive Processes Supporting Episodic Memory Formation in Childhood: The Role of Source Memory, Binding, and Executive Functioning

    Science.gov (United States)

    Raj, Vinaya; Bell, Martha Ann

    2010-01-01

    Episodic memories contain various forms of contextual detail (e.g., perceptual, emotional, cognitive details) that need to become integrated. Each of these contextual features can be used to attribute a memory episode to its source, or origin of information. Memory for source information is one critical component in the formation of episodic…

  9. Delayed onset of a daytime nap facilitates retention of declarative memory.

    Directory of Open Access Journals (Sweden)

    Sara E Alger

    Full Text Available BACKGROUND: Learning followed by a period of sleep, even as little as a nap, promotes memory consolidation. It is now generally recognized that sleep facilitates the stabilization of information acquired prior to sleep. However, the temporal nature of the effect of sleep on retention of declarative memory is yet to be understood. We examined the impact of a delayed nap onset on the recognition of neutral pictorial stimuli with an added spatial component. METHODOLOGY/PRINCIPAL FINDINGS: Participants completed an initial study session involving 150 neutral pictures of people, places, and objects. Immediately following the picture presentation, participants were asked to make recognition judgments on a subset of "old", previously seen, pictures versus intermixed "new" pictures. Participants were then divided into one of four groups who either took a 90-minute nap immediately, 2 hours, or 4 hours after learning, or remained awake for the duration of the experiment. 6 hours after initial learning, participants were again tested on the remaining "old" pictures, with "new" pictures intermixed. CONCLUSIONS/SIGNIFICANCE: Interestingly, we found a stabilizing benefit of sleep on the memory trace reflected as a significant negative correlation between the average time elapsed before napping and decline in performance from test to retest (p = .001. We found a significant interaction between the groups and their performance from test to retest (p = .010, with the 4-hour delay group performing significantly better than both those who slept immediately and those who remained awake (p = .044, p = .010, respectively. Analysis of sleep data revealed a significant positive correlation between amount of slow wave sleep (SWS achieved and length of the delay before sleep onset (p = .048. The findings add to the understanding of memory processing in humans, suggesting that factors such as waking processing and homeostatic increases in need for sleep over time modulate

  10. ERP evidence that auditory-visual speech facilitates working memory in younger and older adults.

    Science.gov (United States)

    Frtusova, Jana B; Winneke, Axel H; Phillips, Natalie A

    2013-06-01

    Auditory-visual (AV) speech enhances speech perception and facilitates auditory processing, as measured by event-related brain potentials (ERPs). Considering a perspective of shared resources between perceptual and cognitive processes, facilitated speech perception may render more resources available for higher-order functions. This study examined whether AV speech facilitation leads to better working memory (WM) performance in 23 younger and 20 older adults. Participants completed an n-back task (0- to 3-back) under visual-only (V-only), auditory-only (A-only), and AV conditions. The results showed faster responses across all memory loads and improved accuracy in the most demanding conditions (2- and 3-back) during AV compared with unisensory conditions. Older adults benefited from the AV presentation to the same extent as younger adults. WM performance of older adults during the AV presentation did not differ from that of younger adults in the A-only condition, suggesting that an AV presentation can help to counteract some of the age-related WM decline. The ERPs showed a decrease in the auditory N1 amplitude during the AV compared with A-only presentation in older adults, suggesting that the facilitation of perceptual processing becomes especially beneficial with aging. Additionally, the N1 occurred earlier in the AV than in the A-only condition for both age groups. These AV-induced modulations of auditory processing correlated with improvement in certain behavioral and ERP measures of WM. These results support an integrated model between perception and cognition, and suggest that processing speech under AV conditions enhances WM performance of both younger and older adults. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  11. Past, present, and future in hippocampal formation and memory research.

    Science.gov (United States)

    Muñoz-López, Mónica

    2015-06-01

    Over 100 years of research on the hippocampal formation has led us understand the consequences of lesions in humans, the functional networks, anatomical pathways, neuronal types and their local circuitry, receptors, molecules, intracellular cascades, and some of the physiological mechanisms underlying long-term spatial and episodic memory. In addition, complex computational models allow us to formulate sophisticated hypotheses; many of them testable with techniques recently developed unthinkable in the past. Although the neurobiology of the cognitive map is starting to be revealed today, we still face a future with many unresolved questions. The aim of this commentary is twofold. First is to point out some of the critical findings in hippocampal formation research and new challenges. Second, to briefly summarize what the anatomy of memory can tell us about how highly processed sensory information from distant cortical areas communicate with different subareas of the entorhinal cortex, dentate gyrus, and hippocampal subfields to integrate and consolidate unique episodic memory traces. © 2015 Wiley Periodicals, Inc.

  12. Histone Deacetylase Inhibition via RGFP966 Releases the Brakes on Sensory Cortical Plasticity and the Specificity of Memory Formation.

    Science.gov (United States)

    Bieszczad, Kasia M; Bechay, Kiro; Rusche, James R; Jacques, Vincent; Kudugunti, Shashi; Miao, Wenyan; Weinberger, Norman M; McGaugh, James L; Wood, Marcelo A

    2015-09-23

    Research over the past decade indicates a novel role for epigenetic mechanisms in memory formation. Of particular interest is chromatin modification by histone deacetylases (HDACs), which, in general, negatively regulate transcription. HDAC deletion or inhibition facilitates transcription during memory consolidation and enhances long-lasting forms of synaptic plasticity and long-term memory. A key open question remains: How does blocking HDAC activity lead to memory enhancements? To address this question, we tested whether a normal function of HDACs is to gate information processing during memory formation. We used a class I HDAC inhibitor, RGFP966 (C21H19FN4O), to test the role of HDAC inhibition for information processing in an auditory memory model of learning-induced cortical plasticity. HDAC inhibition may act beyond memory enhancement per se to instead regulate information in ways that lead to encoding more vivid sensory details into memory. Indeed, we found that RGFP966 controls memory induction for acoustic details of sound-to-reward learning. Rats treated with RGFP966 while learning to associate sound with reward had stronger memory and additional information encoded into memory for highly specific features of sounds associated with reward. Moreover, behavioral effects occurred with unusually specific plasticity in primary auditory cortex (A1). Class I HDAC inhibition appears to engage A1 plasticity that enables additional acoustic features to become encoded in memory. Thus, epigenetic mechanisms act to regulate sensory cortical plasticity, which offers an information processing mechanism for gating what and how much is encoded to produce exceptionally persistent and vivid memories. Significance statement: Here we provide evidence of an epigenetic mechanism for information processing. The study reveals that a class I HDAC inhibitor (Malvaez et al., 2013; Rumbaugh et al., 2015; RGFP966, chemical formula C21H19FN4O) alters the formation of auditory memory by

  13. Histone Deacetylase Inhibition via RGFP966 Releases the Brakes on Sensory Cortical Plasticity and the Specificity of Memory Formation

    Science.gov (United States)

    Bechay, Kiro; Rusche, James R.; Jacques, Vincent; Kudugunti, Shashi; Miao, Wenyan; Weinberger, Norman M.; McGaugh, James L.

    2015-01-01

    Research over the past decade indicates a novel role for epigenetic mechanisms in memory formation. Of particular interest is chromatin modification by histone deacetylases (HDACs), which, in general, negatively regulate transcription. HDAC deletion or inhibition facilitates transcription during memory consolidation and enhances long-lasting forms of synaptic plasticity and long-term memory. A key open question remains: How does blocking HDAC activity lead to memory enhancements? To address this question, we tested whether a normal function of HDACs is to gate information processing during memory formation. We used a class I HDAC inhibitor, RGFP966 (C21H19FN4O), to test the role of HDAC inhibition for information processing in an auditory memory model of learning-induced cortical plasticity. HDAC inhibition may act beyond memory enhancement per se to instead regulate information in ways that lead to encoding more vivid sensory details into memory. Indeed, we found that RGFP966 controls memory induction for acoustic details of sound-to-reward learning. Rats treated with RGFP966 while learning to associate sound with reward had stronger memory and additional information encoded into memory for highly specific features of sounds associated with reward. Moreover, behavioral effects occurred with unusually specific plasticity in primary auditory cortex (A1). Class I HDAC inhibition appears to engage A1 plasticity that enables additional acoustic features to become encoded in memory. Thus, epigenetic mechanisms act to regulate sensory cortical plasticity, which offers an information processing mechanism for gating what and how much is encoded to produce exceptionally persistent and vivid memories. SIGNIFICANCE STATEMENT Here we provide evidence of an epigenetic mechanism for information processing. The study reveals that a class I HDAC inhibitor (Malvaez et al., 2013; Rumbaugh et al., 2015; RGFP966, chemical formula C21H19FN4O) alters the formation of auditory memory by

  14. Proinflammatory Adhesion Molecules Facilitate Polychlorinated Biphenyl–Mediated Enhancement of Brain Metastasis Formation

    OpenAIRE

    Sipos, Eszter; Chen, Lei; András, Ibolya E.; Wrobel, Jagoda; Zhang, Bei; Pu, Hong; Park, Minseon; Eum, Sung Yong; Toborek, Michal

    2012-01-01

    Polychlorinated biphenyls (PCBs) are environmental toxicants that cause vascular inflammation and facilitate the development of brain metastases. The crucial event in metastasis formation is adhesion of blood-borne tumor cells to the vascular endothelium, followed by their transcapillary migration. The aim of the present study was to examine the mechanisms of PCB118-induced brain metastasis formation at the blood-brain barrier level with the focus on tumor cell adhesion to the brain endotheli...

  15. Exploring the influence of encoding format on subsequent memory.

    Science.gov (United States)

    Turney, Indira C; Dennis, Nancy A; Maillet, David; Rajah, M Natasha

    2017-05-01

    Distinctive encoding is greatly influenced by gist-based processes and has been shown to suffer when highly similar items are presented in close succession. Thus, elucidating the mechanisms underlying how presentation format affects gist processing is essential in determining the factors that influence these encoding processes. The current study utilised multivariate partial least squares (PLS) analysis to identify encoding networks directly associated with retrieval performance in a blocked and intermixed presentation condition. Subsequent memory analysis for successfully encoded items indicated no significant differences between reaction time and retrieval performance and presentation format. Despite no significant behavioural differences, behaviour PLS revealed differences in brain-behaviour correlations and mean condition activity in brain regions associated with gist-based vs. distinctive encoding. Specifically, the intermixed format encouraged more distinctive encoding, showing increased activation of regions associated with strategy use and visual processing (e.g., frontal and visual cortices, respectively). Alternatively, the blocked format exhibited increased gist-based processes, accompanied by increased activity in the right inferior frontal gyrus. Together, results suggest that the sequence that information is presented during encoding affects the degree to which distinctive encoding is engaged. These findings extend our understanding of the Fuzzy Trace Theory and the role of presentation format on encoding processes.

  16. Synaptic potentiation facilitates memory-like attractor dynamics in cultured in vitro hippocampal networks.

    Directory of Open Access Journals (Sweden)

    Mark Niedringhaus

    Full Text Available Collective rhythmic dynamics from neurons is vital for cognitive functions such as memory formation but how neurons self-organize to produce such activity is not well understood. Attractor-based computational models have been successfully implemented as a theoretical framework for memory storage in networks of neurons. Additionally, activity-dependent modification of synaptic transmission is thought to be the physiological basis of learning and memory. The goal of this study is to demonstrate that using a pharmacological treatment that has been shown to increase synaptic strength within in vitro networks of hippocampal neurons follows the dynamical postulates theorized by attractor models. We use a grid of extracellular electrodes to study changes in network activity after this perturbation and show that there is a persistent increase in overall spiking and bursting activity after treatment. This increase in activity appears to recruit more "errant" spikes into bursts. Phase plots indicate a conserved activity pattern suggesting that a synaptic potentiation perturbation to the attractor leaves it unchanged. Lastly, we construct a computational model to demonstrate that these synaptic perturbations can account for the dynamical changes seen within the network.

  17. Small-conductance Ca2+-activated potassium type 2 channels regulate the formation of contextual fear memory.

    Directory of Open Access Journals (Sweden)

    Saravana R K Murthy

    Full Text Available Small-conductance, Ca2+ activated K+ channels (SK channels are expressed at high levels in brain regions responsible for learning and memory. In the current study we characterized the contribution of SK2 channels to synaptic plasticity and to different phases of hippocampal memory formation. Selective SK2 antisense-treatment facilitated basal synaptic transmission and theta-burst induced LTP in hippocampal brain slices. Using the selective SK2 antagonist Lei-Dab7 or SK2 antisense probes, we found that hippocampal SK2 channels are critical during two different time windows: 1 blockade of SK2 channels before the training impaired fear memory, whereas, 2 blockade of SK2 channels immediately after the training enhanced contextual fear memory. We provided the evidence that the post-training cleavage of the SK2 channels was responsible for the observed bidirectional effect of SK2 channel blockade on memory consolidation. Thus, Lei-Dab7-injection before training impaired the C-terminal cleavage of SK2 channels, while Lei-Dab7 given immediately after training facilitated the C-terminal cleavage. Application of the synthetic peptide comprising a leucine-zipper domain of the C-terminal fragment to Jurkat cells impaired SK2 channel-mediated currents, indicating that the endogenously cleaved fragment might exert its effects on memory formation by blocking SK2 channel-mediated currents. Our present findings suggest that SK2 channel proteins contribute to synaptic plasticity and memory not only as ion channels but also by additionally generating a SK2 C-terminal fragment, involved in both processes. The modulation of fear memory by down-regulating SK2 C-terminal cleavage might have applicability in the treatment of anxiety disorders in which fear conditioning is enhanced.

  18. Associations of unilateral whisker and olfactory signals induce synapse formation and memory cell recruitment in bilateral barrel cortices: cellular mechanism for unilateral training toward bilateral memory

    Directory of Open Access Journals (Sweden)

    Zilong Gao

    2016-12-01

    Full Text Available Somatosensory signals and operative skills learned by unilateral limbs can be retrieved bilaterally. In terms of cellular mechanism underlying this unilateral learning toward bilateral memory, we hypothesized that associative memory cells in bilateral cortices and synapse innervations between them were produced. In the examination of this hypothesis, we have observed that paired unilateral whisker and odor stimulations led to odorant-induced whisker motions in bilateral sides, which were attenuated by inhibiting the activity of barrel cortices. In the mice that showed bilateral cross-modal responses, the neurons in both sides of barrel cortices became to encode this new odor signal alongside the innate whisker signal. Axon projections and synapse formations from the barrel cortex, which was co-activated with the piriform cortex, toward its contralateral barrel cortex were upregulated. Glutamatergic synaptic transmission in bilateral barrel cortices was upregulated and GABAergic synaptic transmission was downregulated. The associative activations of the sensory cortices facilitate new axon projection, glutamatergic synapse formation and GABAergic synapse downregulation, which drive the neurons to be recruited as associative memory cells in the bilateral cortices. Our data reveals the productions of associative memory cells and synapse innervations in bilateral sensory cortices for unilateral training toward bilateral memory.

  19. Sleeping on the rubber-hand illusion: Memory reactivation during sleep facilitates multisensory recalibration.

    Science.gov (United States)

    Honma, Motoyasu; Plass, John; Brang, David; Florczak, Susan M; Grabowecky, Marcia; Paller, Ken A

    2016-01-01

    Plasticity is essential in body perception so that physical changes in the body can be accommodated and assimilated. Multisensory integration of visual, auditory, tactile, and proprioceptive signals contributes both to conscious perception of the body's current state and to associated learning. However, much is unknown about how novel information is assimilated into body perception networks in the brain. Sleep-based consolidation can facilitate various types of learning via the reactivation of networks involved in prior encoding or through synaptic down-scaling. Sleep may likewise contribute to perceptual learning of bodily information by providing an optimal time for multisensory recalibration. Here we used methods for targeted memory reactivation (TMR) during slow-wave sleep to examine the influence of sleep-based reactivation of experimentally induced alterations in body perception. The rubber-hand illusion was induced with concomitant auditory stimulation in 24 healthy participants on 3 consecutive days. While each participant was sleeping in his or her own bed during intervening nights, electrophysiological detection of slow-wave sleep prompted covert stimulation with either the sound heard during illusion induction, a counterbalanced novel sound, or neither. TMR systematically enhanced feelings of bodily ownership after subsequent inductions of the rubber-hand illusion. TMR also enhanced spatial recalibration of perceived hand location in the direction of the rubber hand. This evidence for a sleep-based facilitation of a body-perception illusion demonstrates that the spatial recalibration of multisensory signals can be altered overnight to stabilize new learning of bodily representations. Sleep-based memory processing may thus constitute a fundamental component of body-image plasticity.

  20. Maternal intake of cashew nuts accelerates reflex maturation and facilitates memory in the offspring.

    Science.gov (United States)

    de Melo, Marília Ferreira Frazão Tavares; Pereira, Diego Elias; Sousa, Morgana Moura; Medeiros, Dilian Maise Ferreira; Lemos, Leanderson Tulio Marques; Madruga, Marta Suely; Santos, Nayane Medeiros; de Oliveira, Maria Elieidy Gomes; de Menezes, Camila Carolina; Soares, Juliana Késsia Barbosa

    2017-10-01

    Essential fatty acids, being indispensable during the stages of pregnancy, lactation and infancy influence the transmission of nerve impulses and brain function, and cashew nuts are a good source of these fatty acids. The objective of this study was to evaluate the effects of cashew nut consumption on reflex development, memory and profile of fatty acids of rat offspring treated during pregnancy and lactation. The animals were divided into three groups: Control (CONT), treated with 7% lipid derived from soybean oil; Normolipidic (NL) treated with 7% lipids derived from cashew nuts; and Hyperlipidic (HL) treated with 20% lipids derived from cashew nuts. Reflex ontogeny, Open-field habituation test and the Object Recognition Test (ORT) were assessed. The profile of fatty acids in the brain was carried out when the animals were zero, 21 and 60days old. Accelerated reflex maturation was observed in animals treated with cashew nuts (pacids and less Docosahexaenoic acid (DHA) in animals of the HL. The data showed that maternal consumption of cashew nuts can accelerate reflex maturation and facilitate memory in offspring when offered in adequate quantities. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  1. A Critical Role for the Nucleus Reuniens in Long-Term, But Not Short-Term Associative Recognition Memory Formation.

    Science.gov (United States)

    Barker, Gareth R I; Warburton, Elizabeth Clea

    2018-03-28

    Recognition memory for single items requires the perirhinal cortex (PRH), whereas recognition of an item and its associated location requires a functional interaction among the PRH, hippocampus (HPC), and medial prefrontal cortex (mPFC). Although the precise mechanisms through which these interactions are effected are unknown, the nucleus reuniens (NRe) has bidirectional connections with each regions and thus may play a role in recognition memory. Here we investigated, in male rats, whether specific manipulations of NRe function affected performance of recognition memory for single items, object location, or object-in-place associations. Permanent lesions in the NRe significantly impaired long-term, but not short-term, object-in-place associative recognition memory, whereas single item recognition memory and object location memory were unaffected. Temporary inactivation of the NRe during distinct phases of the object-in-place task revealed its importance in both the encoding and retrieval stages of long-term associative recognition memory. Infusions of specific receptor antagonists showed that encoding was dependent on muscarinic and nicotinic cholinergic neurotransmission, whereas NMDA receptor neurotransmission was not required. Finally, we found that long-term object-in-place memory required protein synthesis within the NRe. These data reveal a specific role for the NRe in long-term associative recognition memory through its interactions with the HPC and mPFC, but not the PRH. The delay-dependent involvement of the NRe suggests that it is not a simple relay station between brain regions, but, rather, during high mnemonic demand, facilitates interactions between the mPFC and HPC, a process that requires both cholinergic neurotransmission and protein synthesis. SIGNIFICANCE STATEMENT Recognizing an object and its associated location, which is fundamental to our everyday memory, requires specific hippocampal-cortical interactions, potentially facilitated by the

  2. Visual working memory simultaneously guides facilitation and inhibition during visual search.

    Science.gov (United States)

    Dube, Blaire; Basciano, April; Emrich, Stephen M; Al-Aidroos, Naseem

    2016-07-01

    During visual search, visual working memory (VWM) supports the guidance of attention in two ways: It stores the identity of the search target, facilitating the selection of matching stimuli in the search array, and it maintains a record of the distractors processed during search so that they can be inhibited. In two experiments, we investigated whether the full contents of VWM can be used to support both of these abilities simultaneously. In Experiment 1, participants completed a preview search task in which (a) a subset of search distractors appeared before the remainder of the search items, affording participants the opportunity to inhibit them, and (b) the search target varied from trial to trial, requiring the search target template to be maintained in VWM. We observed the established signature of VWM-based inhibition-reduced ability to ignore previewed distractors when the number of distractors exceeds VWM's capacity-suggesting that VWM can serve this role while also representing the target template. In Experiment 2, we replicated Experiment 1, but added to the search displays a singleton distractor that sometimes matched the color (a task-irrelevant feature) of the search target, to evaluate capture. We again observed the signature of VWM-based preview inhibition along with attentional capture by (and, thus, facilitation of) singletons matching the target template. These findings indicate that more than one VWM representation can bias attention at a time, and that these representations can separately affect selection through either facilitation or inhibition, placing constraints on existing models of the VWM-based guidance of attention.

  3. The Role of Long-Term Memory in a Test of Visual Working Memory: Proactive Facilitation but No Proactive Interference

    Science.gov (United States)

    Oberauer, Klaus; Awh, Edward; Sutterer, David W.

    2017-01-01

    We report 4 experiments examining whether associations in visual working memory are subject to proactive interference from long-term memory (LTM). Following a long-term learning phase in which participants learned the colors of 120 unique objects, a working memory (WM) test was administered in which participants recalled the precise colors of 3…

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

    Science.gov (United States)

    Eisenhardt, Dorothea

    2014-01-01

    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…

  5. Working memory binding and episodic memory formation in aging, mild cognitive impairment, and Alzheimer’s dementia

    NARCIS (Netherlands)

    Geldorp, B. van; Heringa, S.M.; Berg, E. van den; Olde Rikkert, M.G.M.; Biessels, G.J.; Kessels, R.P.C.

    2015-01-01

    Introduction: Recent studies indicate that in both normal and pathological aging working memory (WM) performance deteriorates, especially when associations have to be maintained. However, most studies typically do not assess the relationship between WM and episodic memory formation. In the present

  6. Inhibiting corticosterone synthesis during fear memory formation exacerbates cued fear extinction memory deficits within the single prolonged stress model.

    Science.gov (United States)

    Keller, Samantha M; Schreiber, William B; Stanfield, Briana R; Knox, Dayan

    2015-01-01

    Using the single prolonged stress (SPS) animal model of post-traumatic stress disorder (PTSD), previous studies suggest that enhanced glucocorticoid receptor (GR) expression leads to cued fear extinction retention deficits. However, it is unknown how the endogenous ligand of GRs, corticosterone (CORT), may contribute to extinction retention deficits in the SPS model. Given that CORT synthesis during fear learning is critical for fear memory consolidation and SPS enhances GR expression, CORT synthesis during fear memory formation could strengthen fear memory in SPS rats by enhancing GR activation during fear learning. In turn, this could lead to cued fear extinction retention deficits. We tested the hypothesis that CORT synthesis during fear learning leads to cued fear extinction retention deficits in SPS rats by administering the CORT synthesis inhibitor metyrapone to SPS and control rats prior to fear conditioning, and observed the effect this had on extinction memory. Inhibiting CORT synthesis during fear memory formation in control rats tended to decrease cued freezing, though this effect never reached statistical significance. Contrary to our hypothesis, inhibiting CORT synthesis during fear memory formation disrupted extinction retention in SPS rats. This finding suggests that even though SPS exposure leads to cued fear extinction memory deficits, CORT synthesis during fear memory formation enhances extinction retention in SPS rats. This suggests that stress-induced CORT synthesis in previously stressed rats can be beneficial. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. [Spatial Cognition and Episodic Memory Formation in the Limbic Cortex].

    Science.gov (United States)

    Kobayashi, Yasushi

    2017-04-01

    The limbic lobe defined by Broca is a cortical region with highly diverse structure and functions, and comprises the paleo-, archi-, and neocortices as well as their transitional zones. In the limbic lobe, Brodmann designated areas 27, 28, 34, 35, and 36 adjacent to the hippocampus, and areas 23, 24, 25, 26, 29, 30, 31, 32, and 33 around the corpus callosum. In the current literature, areas 27 and 28 correspond to the presubiculum and entorhinal cortex, respectively. Area 34 represents the cortico-medial part of the amygdaloid complex. Areas 35 and 36 roughly cover the perirhinal and parahippocampal cortices. Areas 24, 25, 32, and 33 belong to the anterior cingulate gyrus, while areas 23, 26, 29, 30, and 31 to the posterior cingulate gyrus. Areas 25, 32, and the anteroinferior portion of area 24 are deeply involved in emotional responses, particularly in their autonomic functions, through reciprocal connections with the amygdaloid complex, anterior thalamus and projections to the brainstem and spinal visceral centers. Areas 29 and 30 have dense reciprocal connections with areas 23 and 31, the dorsolateral prefrontal areas, and the regions related to the hippocampus. They play pivotal roles in mediating spatial cognition, working memory processing, and episodic memory formation.

  8. DNA methylation regulates neurophysiological spatial representation in memory formation

    Directory of Open Access Journals (Sweden)

    Eric D. Roth

    2015-04-01

    Full Text Available Epigenetic mechanisms including altered DNA methylation are critical for altered gene transcription subserving synaptic plasticity and the retention of learned behavior. Here, we tested the idea that one role for activity-dependent altered DNA methylation is stabilization of cognition-associated hippocampal place cell firing in response to novel place learning. We observed that a behavioral protocol (spatial exploration of a novel environment known to induce hippocampal place cell remapping resulted in alterations of hippocampal Bdnf DNA methylation. Further studies using neurophysiological in vivo single-unit recordings revealed that pharmacological manipulations of DNA methylation decreased long-term but not short-term place field stability. Together, our data highlight a role for DNA methylation in regulating neurophysiological spatial representation and memory formation.

  9. DNA methylation regulates neurophysiological spatial representation in memory formation.

    Science.gov (United States)

    Roth, Eric D; Roth, Tania L; Money, Kelli M; SenGupta, Sonda; Eason, Dawn E; Sweatt, J David

    2015-04-01

    Epigenetic mechanisms including altered DNA methylation are critical for altered gene transcription subserving synaptic plasticity and the retention of learned behavior. Here we tested the idea that one role for activity-dependent altered DNA methylation is stabilization of cognition-associated hippocampal place cell firing in response to novel place learning. We observed that a behavioral protocol (spatial exploration of a novel environment) known to induce hippocampal place cell remapping resulted in alterations of hippocampal Bdnf DNA methylation. Further studies using neurophysiological in vivo single unit recordings revealed that pharmacological manipulations of DNA methylation decreased long-term but not short-term place field stability. Together our data highlight a role for DNA methylation in regulating neurophysiological spatial representation and memory formation.

  10. Identification of genes that promote or inhibit olfactory memory formation in Drosophila.

    Science.gov (United States)

    Walkinshaw, Erica; Gai, Yunchao; Farkas, Caitlin; Richter, Daniel; Nicholas, Eric; Keleman, Krystyna; Davis, Ronald L

    2015-04-01

    Genetic screens in Drosophila melanogaster and other organisms have been pursued to filter the genome for genetic functions important for memory formation. Such screens have employed primarily chemical or transposon-mediated mutagenesis and have identified numerous mutants including classical memory mutants, dunce and rutabaga. Here, we report the results of a large screen using panneuronal RNAi expression to identify additional genes critical for memory formation. We identified >500 genes that compromise memory when inhibited (low hits), either by disrupting the development and normal function of the adult animal or by participating in the neurophysiological mechanisms underlying memory formation. We also identified >40 genes that enhance memory when inhibited (high hits). The dunce gene was identified as one of the low hits and further experiments were performed to map the effects of the dunce RNAi to the α/β and γ mushroom body neurons. Additional behavioral experiments suggest that dunce knockdown in the mushroom body neurons impairs memory without significantly affecting acquisition. We also characterized one high hit, sickie, to show that RNAi knockdown of this gene enhances memory through effects in dopaminergic neurons without apparent effects on acquisition. These studies further our understanding of two genes involved in memory formation, provide a valuable list of genes that impair memory that may be important for understanding the neurophysiology of memory or neurodevelopmental disorders, and offer a new resource of memory suppressor genes that will aid in understanding restraint mechanisms employed by the brain to optimize resources. Copyright © 2015 by the Genetics Society of America.

  11. Level of Processing Modulates the Neural Correlates of Emotional Memory Formation

    Science.gov (United States)

    Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2011-01-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study used a levels-of-processing manipulation to characterize the impact of emotion on…

  12. Shp2 in Forebrain Neurons Regulates Synaptic Plasticity, Locomotion, and Memory Formation in Mice

    Science.gov (United States)

    Kusakari, Shinya; Saitow, Fumihito; Ago, Yukio; Shibasaki, Koji; Sato-Hashimoto, Miho; Matsuzaki, Yasunori; Kotani, Takenori; Murata, Yoji; Hirai, Hirokazu; Matsuda, Toshio; Suzuki, Hidenori

    2015-01-01

    Shp2 (Src homology 2 domain-containing protein tyrosine phosphatase 2) regulates neural cell differentiation. It is also expressed in postmitotic neurons, however, and mutations of Shp2 are associated with clinical syndromes characterized by mental retardation. Here we show that conditional-knockout (cKO) mice lacking Shp2 specifically in postmitotic forebrain neurons manifest abnormal behavior, including hyperactivity. Novelty-induced expression of immediate-early genes and activation of extracellular-signal-regulated kinase (Erk) were attenuated in the cerebral cortex and hippocampus of Shp2 cKO mice, suggestive of reduced neuronal activity. In contrast, ablation of Shp2 enhanced high-K+-induced Erk activation in both cultured cortical neurons and synaptosomes, whereas it inhibited that induced by brain-derived growth factor in cultured neurons. Posttetanic potentiation and paired-pulse facilitation were attenuated and enhanced, respectively, in hippocampal slices from Shp2 cKO mice. The mutant mice also manifested transient impairment of memory formation in the Morris water maze. Our data suggest that Shp2 contributes to regulation of Erk activation and synaptic plasticity in postmitotic forebrain neurons and thereby controls locomotor activity and memory formation. PMID:25713104

  13. The effects of refreshing and elaboration on working memory performance, and their contributions to long-term memory formation.

    Science.gov (United States)

    Bartsch, Lea M; Singmann, Henrik; Oberauer, Klaus

    2018-03-19

    Refreshing and elaboration are cognitive processes assumed to underlie verbal working-memory maintenance and assumed to support long-term memory formation. Whereas refreshing refers to the attentional focussing on representations, elaboration refers to linking representations in working memory into existing semantic networks. We measured the impact of instructed refreshing and elaboration on working and long-term memory separately, and investigated to what extent both processes are distinct in their contributions to working as well as long-term memory. Compared with a no-processing baseline, immediate memory was improved by repeating the items, but not by refreshing them. There was no credible effect of elaboration on working memory, except when items were repeated at the same time. Long-term memory benefited from elaboration, but not from refreshing the words. The results replicate the long-term memory benefit for elaboration, but do not support its beneficial role for working memory. Further, refreshing preserves immediate memory, but does not improve it beyond the level achieved without any processing.

  14. Prolonged rote learning produces delayed memory facilitation and metabolic changes in the hippocampus of the ageing human brain.

    LENUS (Irish Health Repository)

    Roche, Richard Ap

    2009-01-01

    BACKGROUND: Repeated rehearsal is one method by which verbal material may be transferred from short- to long-term memory. We hypothesised that extended engagement of memory structures through prolonged rehearsal would result in enhanced efficacy of recall and also of brain structures implicated in new learning. Twenty-four normal participants aged 55-70 (mean = 60.1) engaged in six weeks of rote learning, during which they learned 500 words per week every week (prose, poetry etc.). An extensive battery of memory tests was administered on three occasions, each six weeks apart. In addition, proton magnetic resonance spectroscopy (1H-MRS) was used to measure metabolite levels in seven voxels of interest (VOIs) (including hippocampus) before and after learning. RESULTS: Results indicate a facilitation of new learning that was evident six weeks after rote learning ceased. This facilitation occurred for verbal\\/episodic material only, and was mirrored by a metabolic change in left posterior hippocampus, specifically an increase in NAA\\/(Cr+Cho) ratio. CONCLUSION: Results suggest that repeated activation of memory structures facilitates anamnesis and may promote neuronal plasticity in the ageing brain, and that compliance is a key factor in such facilitation as the effect was confined to those who engaged fully with the training.

  15. Prolonged rote learning produces delayed memory facilitation and metabolic changes in the hippocampus of the ageing human brain

    Directory of Open Access Journals (Sweden)

    Prendergast Julie

    2009-11-01

    Full Text Available Abstract Background Repeated rehearsal is one method by which verbal material may be transferred from short- to long-term memory. We hypothesised that extended engagement of memory structures through prolonged rehearsal would result in enhanced efficacy of recall and also of brain structures implicated in new learning. Twenty-four normal participants aged 55-70 (mean = 60.1 engaged in six weeks of rote learning, during which they learned 500 words per week every week (prose, poetry etc.. An extensive battery of memory tests was administered on three occasions, each six weeks apart. In addition, proton magnetic resonance spectroscopy (1H-MRS was used to measure metabolite levels in seven voxels of interest (VOIs (including hippocampus before and after learning. Results Results indicate a facilitation of new learning that was evident six weeks after rote learning ceased. This facilitation occurred for verbal/episodic material only, and was mirrored by a metabolic change in left posterior hippocampus, specifically an increase in NAA/(Cr+Cho ratio. Conclusion Results suggest that repeated activation of memory structures facilitates anamnesis and may promote neuronal plasticity in the ageing brain, and that compliance is a key factor in such facilitation as the effect was confined to those who engaged fully with the training.

  16. Prolonged rote learning produces delayed memory facilitation and metabolic changes in the hippocampus of the ageing human brain.

    Science.gov (United States)

    Roche, Richard Ap; Mullally, Sinéad L; McNulty, Jonathan P; Hayden, Judy; Brennan, Paul; Doherty, Colin P; Fitzsimons, Mary; McMackin, Deirdre; Prendergast, Julie; Sukumaran, Sunita; Mangaoang, Maeve A; Robertson, Ian H; O'Mara, Shane M

    2009-11-20

    Repeated rehearsal is one method by which verbal material may be transferred from short- to long-term memory. We hypothesised that extended engagement of memory structures through prolonged rehearsal would result in enhanced efficacy of recall and also of brain structures implicated in new learning. Twenty-four normal participants aged 55-70 (mean = 60.1) engaged in six weeks of rote learning, during which they learned 500 words per week every week (prose, poetry etc.). An extensive battery of memory tests was administered on three occasions, each six weeks apart. In addition, proton magnetic resonance spectroscopy (1H-MRS) was used to measure metabolite levels in seven voxels of interest (VOIs) (including hippocampus) before and after learning. Results indicate a facilitation of new learning that was evident six weeks after rote learning ceased. This facilitation occurred for verbal/episodic material only, and was mirrored by a metabolic change in left posterior hippocampus, specifically an increase in NAA/(Cr+Cho) ratio. Results suggest that repeated activation of memory structures facilitates anamnesis and may promote neuronal plasticity in the ageing brain, and that compliance is a key factor in such facilitation as the effect was confined to those who engaged fully with the training.

  17. Trichostatin A (TSA) facilitates formation of partner preference in male prairie voles (Microtus ochrogaster).

    Science.gov (United States)

    Duclot, F; Wang, H; Youssef, C; Liu, Y; Wang, Z; Kabbaj, M

    2016-05-01

    In the socially monogamous prairie voles (Microtus ochrogaster), the development of a social bonding is indicated by the formation of partner preference, which involves a variety of environmental and neurochemical factors and brain structures. In a most recent study in female prairie voles, we found that treatment with the histone deacetylase inhibitor trichostatin A (TSA) facilitates the formation of partner preference through up-regulation of oxytocin receptor (OTR) and vasopressin V1a receptor (V1aR) genes expression in the nucleus accumbens (NAcc). In the present study, we tested the hypothesis that TSA treatment also facilitates partner preference formation and alters OTR and V1aR genes expression in the NAcc in male prairie voles. We thus observed that central injection of TSA dose-dependently promoted the formation of partner preference in the absence of mating in male prairie voles. Interestingly, TSA treatment up-regulated OTR, but not V1aR, gene expression in the NAcc similarly as they were affected by mating - an essential process for naturally occurring partner preference. These data, together with others, not only indicate the involvement of epigenetic events but also the potential role of NAcc oxytocin in the regulation of partner preference in both male and female prairie voles. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Facilitation of memory encoding in primate hippocampus by a neuroprosthesis that promotes task-specific neural firing

    Science.gov (United States)

    Hampson, Robert E.; Song, Dong; Opris, Ioan; Santos, Lucas M.; Shin, Dae C.; Gerhardt, Greg A.; Marmarelis, Vasilis Z.; Berger, Theodore W.; Deadwyler, Sam A.

    2013-12-01

    Objective. Memory accuracy is a major problem in human disease and is the primary factor that defines Alzheimer’s, ageing and dementia resulting from impaired hippocampal function in the medial temporal lobe. Development of a hippocampal memory neuroprosthesis that facilitates normal memory encoding in nonhuman primates (NHPs) could provide the basis for improving memory in human disease states. Approach. NHPs trained to perform a short-term delayed match-to-sample (DMS) memory task were examined with multi-neuron recordings from synaptically connected hippocampal cell fields, CA1 and CA3. Recordings were analyzed utilizing a previously developed nonlinear multi-input multi-output (MIMO) neuroprosthetic model, capable of extracting CA3-to-CA1 spatiotemporal firing patterns during DMS performance. Main results. The MIMO model verified that specific CA3-to-CA1 firing patterns were critical for the successful encoding of sample phase information on more difficult DMS trials. This was validated by the delivery of successful MIMO-derived encoding patterns via electrical stimulation to the same CA1 recording locations during the sample phase which facilitated task performance in the subsequent, delayed match phase, on difficult trials that required more precise encoding of sample information. Significance. These findings provide the first successful application of a neuroprosthesis designed to enhance and/or repair memory encoding in primate brain.

  19. The role of rewarding and novel events in facilitating memory persistence in a separate spatial memory task

    Science.gov (United States)

    Salvetti, Beatrice; Morris, Richard G.M.; Wang, Szu-Han

    2014-01-01

    Many insignificant events in our daily life are forgotten quickly but can be remembered for longer when other memory-modulating events occur before or after them. This phenomenon has been investigated in animal models in a protocol in which weak memories persist longer if exploration in a novel context is introduced around the time of memory encoding. This study aims to understand whether other types of rewarding or novel tasks, such as rewarded learning in a T-maze and novel object recognition, can also be effective memory-modulating events. Rats were trained in a delayed matching-to-place task to encode and retrieve food locations in an event arena. Weak encoding with only one food pellet at the sample location induced memory encoding but forgetting over 24 h. When this same weak encoding was followed by a rewarded task in a T-maze, the memory persisted for 24 h. Moreover, the same persistence of memory over 24 h could be achieved by exploration in a novel box or by a rewarded T-maze task after a “non-rewarded” weak encoding. When the one-pellet weak encoding was followed by novel object exploration, the memory did not persist at 24 h. Together, the results confirm that place encoding is possible without explicit reward, and that rewarded learning in a separate task lacking novelty can be an effective memory-modulating event. The behavioral and neurobiological implications are discussed. PMID:24429424

  20. Iconic Gestures Facilitate Discourse Comprehension in Individuals With Superior Immediate Memory for Body Configurations.

    Science.gov (United States)

    Wu, Ying Choon; Coulson, Seana

    2015-11-01

    To understand a speaker's gestures, people may draw on kinesthetic working memory (KWM)-a system for temporarily remembering body movements. The present study explored whether sensitivity to gesture meaning was related to differences in KWM capacity. KWM was evaluated through sequences of novel movements that participants viewed and reproduced with their own bodies. Gesture sensitivity was assessed through a priming paradigm. Participants judged whether multimodal utterances containing congruent, incongruent, or no gestures were related to subsequent picture probes depicting the referents of those utterances. Individuals with low KWM were primarily inhibited by incongruent speech-gesture primes, whereas those with high KWM showed facilitation-that is, they were able to identify picture probes more quickly when preceded by congruent speech and gestures than by speech alone. Group differences were most apparent for discourse with weakly congruent speech and gestures. Overall, speech-gesture congruency effects were positively correlated with KWM abilities, which may help listeners match spatial properties of gestures to concepts evoked by speech. © The Author(s) 2015.

  1. Contextualization: Memory Formation and Retrieval in a Nested Environment

    Science.gov (United States)

    Piefke, Martina; Markowitsch, Hans J.

    Episodic memory functions are highly context-dependent. This is true for both experimental and autobiographical episodic memory. We here review neuropsychological and neuroimaging evidence for effects of differential encoding and retrieval contexts on episodic memory performance as well as the underlying neurofunctional mechanisms. In studies of laboratory episodic memory, the influence of context parameters can be assessed by experimental manipulations. Such experiments suggest that contextual variables mainly affect prefrontal functions supporting executive processes involved in episodic learning and retrieval. Context parameters affecting episodic autobiographical memory are far more complex and cannot easily be controlled. Data support the view that not only prefrontal, but also further medial temporal and posterior parietal regions mediating the re-experience and emotional evaluation of personal memories are highly influenced by changing contextual variables of memory encoding and retrieval. Based on our review of available data, we thus suggest that experimental and autobiographical episodic memories are influenced by both overlapping and differential context parameters.

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

    Directory of Open Access Journals (Sweden)

    Cristina M Alberini

    2011-03-01

    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.

  3. Oscillatory theta activity during memory formation and its impact on overnight consolidation: a missing link?

    Science.gov (United States)

    Heib, Dominik P J; Hoedlmoser, Kerstin; Anderer, Peter; Gruber, Georg; Zeitlhofer, Josef; Schabus, Manuel

    2015-08-01

    Sleep has been shown to promote memory consolidation driven by certain oscillatory patterns, such as sleep spindles. However, sleep does not consolidate all newly encoded information uniformly but rather "selects" certain memories for consolidation. It is assumed that such selection depends on salience tags attached to the new memories before sleep. However, little is known about the underlying neuronal processes reflecting presleep memory tagging. The current study sought to address the question of whether event-related changes in spectral theta power (theta ERSP) during presleep memory formation could reflect memory tagging that influences subsequent consolidation during sleep. Twenty-four participants memorized 160 word pairs before sleep; in a separate laboratory visit, they performed a nonlearning control task. Memory performance was tested twice, directly before and after 8 hr of sleep. Results indicate that participants who improved their memory performance overnight displayed stronger theta ERSP during the memory task in comparison with the control task. They also displayed stronger memory task-related increases in fast sleep spindle activity. Furthermore, presleep theta activity was directly linked to fast sleep spindle activity, indicating that processes during memory formation might indeed reflect memory tagging that influences subsequent consolidation during sleep. Interestingly, our results further indicate that the suggested relation between sleep spindles and overnight performance change is not as direct as once believed. Rather, it appears to be mediated by processes beginning during presleep memory formation. We conclude that theta ERSP during presleep memory formation reflects cortico-hippocampal interactions that lead to a better long-term accessibility by tagging memories for sleep spindle-related reprocessing.

  4. The Role of Rewarding and Novel Events in Facilitating Memory Persistence in a Separate Spatial Memory Task

    Science.gov (United States)

    Salvetti, Beatrice; Morris, Richard G. M.; Wang, Szu-Han

    2014-01-01

    Many insignificant events in our daily life are forgotten quickly but can be remembered for longer when other memory-modulating events occur before or after them. This phenomenon has been investigated in animal models in a protocol in which weak memories persist longer if exploration in a novel context is introduced around the time of memory…

  5. The neurobiological bases of memory formation: from physiological conditions to psychopathology.

    Science.gov (United States)

    Bisaz, Reto; Travaglia, Alessio; Alberini, Cristina M

    2014-01-01

    The formation of long-term memories is a function necessary for an adaptive survival. In the last two decades, great progress has been made in the understanding of the biological bases of memory formation. The identification of mechanisms necessary for memory consolidation and reconsolidation, the processes by which the posttraining and postretrieval fragile memory traces become stronger and insensitive to disruption, has indicated new approaches for investigating and treating psychopathologies. In this review, we will discuss some key biological mechanisms found to be critical for memory consolidation and strengthening, the role/s and mechanisms of memory reconsolidation, and how the interference with consolidation and/or reconsolidation can modulate the retention and/or storage of memories that are linked to psychopathologies. © 2014 S. Karger AG, Basel.

  6. Friend or foe? Decoding the facilitative and disruptive effects of emotion on working memory in younger and older adults

    Directory of Open Access Journals (Sweden)

    Linda eTruong

    2014-02-01

    Full Text Available A growing body of work on emotion-cognition interactions has revealed both facilitative and disruptive effects of emotion on working memory in younger adults. These differing effects may vary by the goal relevancy of emotion within a task. Additionally, it is possible that these emotional effects would be larger for older adults, considering findings of preserved emotional processing with age. To test these hypotheses, the current study examined the effects of emotional content and aging on working memory for target information in the presence of distraction. Thirty-six younger (ages 18-29 and 36 older adults (ages 65-87 completed a delayed-response working memory task. Participants viewed two target words intermixed with two distracter words, and then judged whether a subsequently presented probe word was one of the target words. The emotional content (valence and arousal of targets and distracters was systematically manipulated. Results indicated that emotional targets facilitated working memory in both age groups. In contrast, emotional distracters disrupted performance. Negative distracters were particularly disruptive for older adults, but younger adults did not show an emotional interference effect. These findings help clarify discrepancies in the literature and contribute to the sparse research on emotional working memory in older adults.

  7. Amygdala's involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition.

    Science.gov (United States)

    Chau, Lily S; Galvez, Roberto

    2012-01-01

    It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala's role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS) is paired with a salient unconditioned stimulus (US) that elicits an unconditioned response (UR). After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR). Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala's involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities.

  8. Amygdala’s involvement in facilitating associative learning-induced plasticity: a promiscuous role for the amygdala in memory acquisition

    Directory of Open Access Journals (Sweden)

    Lily S Chau

    2012-10-01

    Full Text Available It is widely accepted that the amygdala plays a critical role in acquisition and consolidation of fear-related memories. Some of the more widely employed behavioral paradigms that have assisted in solidifying the amygdala’s role in fear-related memories are associative learning paradigms. With most associative learning tasks, a neutral conditioned stimulus (CS is paired with a salient unconditioned stimulus (US that elicits an unconditioned response (UR. After multiple CS-US pairings, the subject learns that the CS predicts the onset or delivery of the US, and thus elicits a learned conditioned response (CR. Most fear-related associative paradigms have suggested that an aspect of the fear association is stored in the amygdala; however, some fear-motivated associative paradigms suggest that the amygdala is not a site of storage, but rather facilitates consolidation in other brain regions. Based upon various learning theories, one of the most likely sites for storage of long-term memories is the neocortex. In support of these theories, findings from our laboratory, and others, have demonstrated that trace-conditioning, an associative paradigm where there is a separation in time between the CS and US, induces learning-specific neocortical plasticity. The following review will discuss the amygdala’s involvement, either as a site of storage or facilitating storage in other brain regions such as the neocortex, in fear- and non-fear-motivated associative paradigms. In this review, we will discuss recent findings suggesting a broader role for the amygdala in increasing the saliency of behaviorally relevant information, thus facilitating acquisition for all forms of memory, both fear- and non-fear-related. This proposed promiscuous role of the amygdala in facilitating acquisition for all memories further suggests a potential role of the amygdala in general learning disabilities.

  9. The roles of Eph receptors in contextual fear conditioning memory formation.

    Science.gov (United States)

    Dines, Monica; Grinberg, Svetlana; Vassiliev, Maria; Ram, Alon; Tamir, Tal; Lamprecht, Raphael

    2015-10-01

    Eph receptors regulate glutamate receptors functions, neuronal morphology and synaptic plasticity, cellular events believed to be involved in memory formation. In this study we aim to explore the roles of Eph receptors in learning and memory. Toward that end, we examined the roles of EphB2 and EphA4 receptors, key regulators of synaptic functions, in fear conditioning memory formation. We show that mice lacking EphB2 (EphB2(-/-)) are impaired in short- and long-term contextual fear conditioning memory. Mice that express a carboxy-terminally truncated form of EphB2 that lacks forward signaling, instead of the full EphB2, are impaired in long-term, but not short-term, contextual fear conditioning memory. Long-term contextual fear conditioning memory is attenuated in CaMKII-cre;EphA4(lx/-) mice where EphA4 is removed from all pyramidal neurons of the forebrain. Mutant mice with targeted kinase-dead EphA4 (EphA4(KD)) exhibit intact long-term contextual fear conditioning memory showing that EphA4 kinase-mediated forward signaling is not needed for contextual fear memory formation. The ability to form long-term conditioned taste aversion (CTA) memory is not impaired in the EphB2(-/-) and CaMKII-cre;EphA4(lx/-) mice. We conclude that EphB2 forward signaling is required for long-term contextual fear conditioning memory formation. In contrast, EphB2 mediates short-term contextual fear conditioning memory formation in a forward signaling-independent manner. EphA4 mediates long-term contextual fear conditioning memory formation in a kinase-independent manner. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    OpenAIRE

    Gutiérrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition memory using attenuation of neophobia as an index. In addition, learned taste aversion in both short- and long-term memory tests was exclusively impa...

  11. Sex differences in stress effects on response and spatial memory formation.

    Science.gov (United States)

    Guenzel, Friederike M; Wolf, Oliver T; Schwabe, Lars

    2014-03-01

    Stress and stress hormones are known to affect learning and memory processes. However, although effects of stress on hippocampus-dependent declarative learning and memory are well-documented, relatively little attention has been paid to the impact of stress on striatum-dependent stimulus-response (S-R) learning and memory. Recent evidence indicates that glucocorticoid stress hormones shortly after learning enhance S-R memory consolidation, whereas stress prior to retention testing impairs S-R memory retrieval. Whether stress affects also the acquisition of S-R memories in humans remains unclear. For this reason, we examined here the effects of acute stress on S-R memory formation and contrasted these stress effects with those on hippocampus-dependent spatial memory. Healthy men and women underwent a stressor (socially evaluated cold pressor test, SECPT) or a control manipulation before they completed an S-R task and two spatial learning tasks. Memory was assessed one week later. Our data showed that stress impaired S-R memory performance in men but not in women. Conversely, spatial memory was impaired by stress in women but not in men. These findings provide further evidence that stress may alter learning and memory processes beyond the hippocampus. Moreover, our data underline that participants' sex may play a critical role in the impact of stress on multiple memory systems. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Social Isolation During Adolescence Strengthens Retention of Fear Memories and Facilitates Induction of Late-Phase Long-Term Potentiation.

    Science.gov (United States)

    Liu, Ji-Hong; You, Qiang-Long; Wei, Mei-Dan; Wang, Qian; Luo, Zheng-Yi; Lin, Song; Huang, Lang; Li, Shu-Ji; Li, Xiao-Wen; Gao, Tian-Ming

    2015-12-01

    Social isolation during the vulnerable period of adolescence produces emotional dysregulation that often manifests as abnormal behavior in adulthood. The enduring consequence of isolation might be caused by a weakened ability to forget unpleasant memories. However, it remains unclear whether isolation affects unpleasant memories. To address this, we used a model of associative learning to induce the fear memories and evaluated the influence of isolation mice during adolescence on the subsequent retention of fear memories and its underlying cellular mechanisms. Following adolescent social isolation, we found that mice decreased their social interaction time and had an increase in anxiety-related behavior. Interestingly, when we assessed memory retention, we found that isolated mice were unable to forget aversive memories when tested 4 weeks after the original event. Consistent with this, we observed that a single train of high-frequency stimulation (HFS) enabled a late-phase long-term potentiation (L-LTP) in the hippocampal CA1 region of isolated mice, whereas only an early-phase LTP was observed with the same stimulation in the control mice. Social isolation during adolescence also increased brain-derived neurotrophic factor (BDNF) expression in the hippocampus, and application of a tropomyosin-related kinase B (TrkB) receptor inhibitor ameliorated the facilitated L-LTP seen after isolation. Together, our results suggest that adolescent isolation may result in mental disorders during adulthood and that this may stem from an inability to forget the unpleasant memories via BDNF-mediated synaptic plasticity. These findings may give us a new strategy to prevent mental disorders caused by persistent unpleasant memories.

  13. Inter-individual differences in trait negative affect moderate cortisol's effects on memory formation: preliminary findings from two studies.

    Science.gov (United States)

    Abercrombie, Heather C; Wirth, Michelle M; Hoks, Roxanne M

    2012-05-01

    Acute emotional arousal moderates the effects of cortisol on memory. However, it is currently unknown how stable inter-individual differences (i.e., traits) moderate cortisol's effects on memory. In two studies using within-subjects designs - 31 healthy males in Study 1 and 42 healthy subjects (22 female) in Study 2 - we measured trait negative affect (NA) and presented emotional and neutral pictures. In Study 1, we manipulated endogenous cortisol levels using a speech stressor following encoding. In Study 2, using a randomized placebo-controlled design, we pharmacologically manipulated cortisol levels prior to encoding (0.1mg/kg hydrocortisone vs. saline infused over 30min). Free recall for pictures was subsequently assessed. Trait NA repeatedly moderated the relationship between cortisol and memory formation. Findings suggested the speculative conclusion that the direction of effects may vary by sex. In males, cortisol was related to memory facilitation in subjects with lower Trait NA. Conversely, females with higher Trait NA showed greater cortisol-related increases in memory. Trait NA may be a stable inter-individual difference predicting neurocognitive effects of cortisol during stressors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Level of processing modulates the neural correlates of emotional memory formation

    OpenAIRE

    Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2010-01-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study employed a levels-of-processing manipulation to characterize the impact of emotion on encoding with and without the influence of elaborative processes. Participants viewed emotionally negative, neutral, and positive scenes under ...

  15. Sensory Cortical Plasticity Participates in the Epigenetic Regulation of Robust Memory Formation

    OpenAIRE

    Mimi L. Phan; Kasia M. Bieszczad

    2016-01-01

    Neuroplasticity remodels sensory cortex across the lifespan. A function of adult sensory cortical plasticity may be capturing available information during perception for memory formation. The degree of experience-dependent remodeling in sensory cortex appears to determine memory strength and specificity for important sensory signals. A key open question is how plasticity is engaged to induce different degrees of sensory cortical remodeling. Neural plasticity for long-term memory requires the ...

  16. Working memory cells' behavior may be explained by cross-regional networks with synaptic facilitation.

    Directory of Open Access Journals (Sweden)

    Sergio Verduzco-Flores

    2009-08-01

    Full Text Available Neurons in the cortex exhibit a number of patterns that correlate with working memory. Specifically, averaged across trials of working memory tasks, neurons exhibit different firing rate patterns during the delay of those tasks. These patterns include: 1 persistent fixed-frequency elevated rates above baseline, 2 elevated rates that decay throughout the tasks memory period, 3 rates that accelerate throughout the delay, and 4 patterns of inhibited firing (below baseline analogous to each of the preceding excitatory patterns. Persistent elevated rate patterns are believed to be the neural correlate of working memory retention and preparation for execution of behavioral/motor responses as required in working memory tasks. Models have proposed that such activity corresponds to stable attractors in cortical neural networks with fixed synaptic weights. However, the variability in patterned behavior and the firing statistics of real neurons across the entire range of those behaviors across and within trials of working memory tasks are typical not reproduced. Here we examine the effect of dynamic synapses and network architectures with multiple cortical areas on the states and dynamics of working memory networks. The analysis indicates that the multiple pattern types exhibited by cells in working memory networks are inherent in networks with dynamic synapses, and that the variability and firing statistics in such networks with distributed architectures agree with that observed in the cortex.

  17. Concurrent Working Memory Load Can Facilitate Selective Attention: Evidence for Specialized Load

    Science.gov (United States)

    Park, Soojin; Kim, Min-Shik; Chun, Marvin M.

    2007-01-01

    Load theory predicts that concurrent working memory load impairs selective attention and increases distractor interference (N. Lavie, A. Hirst, J. W. de Fockert, & E. Viding, see record 2004-17825-003). Here, the authors present new evidence that the type of concurrent working memory load determines whether load impairs selective attention or not.…

  18. Involuntary conscious memory facilitates cued recall performance: further evidence that chaining occurs during voluntary recall.

    Science.gov (United States)

    Mace, John H

    2009-01-01

    Recent studies have shown that conscious recollection of the past occurs spontaneously when subjects voluntarily recall their own past experiences or a list of previously studied words. Naturalistic diary studies and laboratory studies of this phenomenon, often called involuntary conscious memory (ICM), show that it occurs in 2 ways. One is direct ICM retrieval, which occurs when a cue spontaneously triggers a conscious memory; the other is chained ICM retrieval, which occurs when a retrieved conscious memory spontaneously triggers another. Laboratory studies investigating ICM show that chained ICM retrieval occurs on voluntary autobiographical memory tasks. The present results show that chained ICM retrieval also occurs on a voluntary word list memory task (cued recall). These results are among a handful suggesting that ICM retrieval routinely occurs during voluntary recall.

  19. Emotion processing in the criminal psychopath: the role of attention in emotion-facilitated memory.

    Science.gov (United States)

    Glass, Samantha J; Newman, Joseph P

    2009-02-01

    The response modulation hypothesis specifies that low-anxious psychopathic individuals have difficulty processing information outside their primary attentional focus. To evaluate the applicability of this model to affective processing, the authors had 239 offenders, classified with the Psychopathy Checklist--Revised (R. D. Hare, 2003) and the Welsh Anxiety Scale (G. Welsh, 1956), perform 1 of 3 emotion memory tasks that examined the effects of emotion on memory for primary and contextual information. Regardless of anxiety level, psychopathic and control offenders demonstrated a significant and comparable memory bias for emotional over neutral words in the primary conditions. However, psychopathic individuals showed significantly less memory bias than did controls in the contextual conditions. Results indicate that the impact of emotion on memory is moderated by attentional factors.

  20. Memory formation orchestrates the wiring of adult-born hippocampal neurons into brain circuits.

    Science.gov (United States)

    Petsophonsakul, Petnoi; Richetin, Kevin; Andraini, Trinovita; Roybon, Laurent; Rampon, Claire

    2017-08-01

    During memory formation, structural rearrangements of dendritic spines provide a mean to durably modulate synaptic connectivity within neuronal networks. New neurons generated throughout the adult life in the dentate gyrus of the hippocampus contribute to learning and memory. As these neurons become incorporated into the network, they generate huge numbers of new connections that modify hippocampal circuitry and functioning. However, it is yet unclear as to how the dynamic process of memory formation influences their synaptic integration into neuronal circuits. New memories are established according to a multistep process during which new information is first acquired and then consolidated to form a stable memory trace. Upon recall, memory is transiently destabilized and vulnerable to modification. Using contextual fear conditioning, we found that learning was associated with an acceleration of dendritic spines formation of adult-born neurons, and that spine connectivity becomes strengthened after memory consolidation. Moreover, we observed that afferent connectivity onto adult-born neurons is enhanced after memory retrieval, while extinction training induces a change of spine shapes. Together, these findings reveal that the neuronal activity supporting memory processes strongly influences the structural dendritic integration of adult-born neurons into pre-existing neuronal circuits. Such change of afferent connectivity is likely to impact the overall wiring of hippocampal network, and consequently, to regulate hippocampal function.

  1. Processes Underlying Developmental Reversals in False-Memory Formation: Comment on Brainerd, Reyna, and Ceci (2008)

    Science.gov (United States)

    Ghetti, Simona

    2008-01-01

    C. J. Brainerd, V. F. Reyna, and S. J. Ceci (2008) reviewed compelling evidence of developmental reversals in false-memory formation (i.e., younger children exhibit lower false-memory rates than do older children and adults) and proposed that this phenomenon depends on the development of gist processing (i.e., the ability to identify and process…

  2. Activation of Midbrain Structures by Associative Novelty and the Formation of Explicit Memory in Humans

    Science.gov (United States)

    Schott, Bjorn H.; Sellner, Daniela B.; Lauer, Corinna-J.; Habib, Reza; Frey, Julietta U.; Guderian, Sebastian; Heinze, Hans-Jochen; Duzel, Emrah

    2004-01-01

    Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study,…

  3. Nitrogen remobilisation facilitates adventitious root formation on reversible dark-induced carbohydrate depletion in Petunia hybrida.

    Science.gov (United States)

    Zerche, Siegfried; Haensch, Klaus-Thomas; Druege, Uwe; Hajirezaei, Mohammad-Reza

    2016-10-10

    cuttings strongly reduced shoot growth during AR formation. The results indicate that both enhanced N t content and dark exposure of cuttings reinforced N signals and mobile N resources in the stem base facilitated by senescence-related proteolysis in leaves. Based on our results, a model of N mobilisation concomitant with carbohydrate depletion and its significance for AR formation is postulated.

  4. Facilitative Effects of Forgetting from Short-Term Memory on Growth of Long-Term Memory in Retardates

    Science.gov (United States)

    Sperber, Richard D.

    1976-01-01

    Competing explanations of the beneficial effect of spacing in retardate discrimination learning were tested. Results are inconsistent with consolidation and rehearsal theories but support the prediction of the Geber, Greenfield, and House spacing model that forgetting from short-term memory facilities retardate learning. (Author/SB)

  5. Time of Day Influences Memory Formation and dCREB2 Proteins in Drosophila

    Directory of Open Access Journals (Sweden)

    Robin eFropf

    2014-03-01

    Full Text Available Many biological phenomena oscillate under the control of the circadian system, exhibiting peaks and troughs of activity across the day/night cycle. In most animal models, memory formation also exhibits this property, but the underlying neuronal and molecular mechanisms remain unclear. The dCREB2 transcription factor shows circadian regulated oscillations in its activity, and has been shown to be important for both circadian biology and memory formation. We show that the time-of-day (TOD of behavioral training affects Drosophila memory formation. dCREB2 exhibits complex changes in protein levels across the daytime and nighttime, and these changes in protein abundance are likely to contribute to oscillations in dCREB2 activity and TOD effects on memory formation.

  6. Expected reward value and reward uncertainty have temporally dissociable effects on memory formation

    OpenAIRE

    Adcock, R; Clement, Nathaniel; Chiew, Kimberly; Dickerson, Kathryn; Stanek, Jessica

    2018-01-01

    Anticipating rewards has been shown to enhance memory formation. While substantial evidence implicates dopamine in this behavioral effect, the precise mechanisms remain ambiguous. Because dopamine nuclei show two distinct physiological signatures of reward prediction, we hypothesized two dissociable effects on memory formation. These two signatures are a phasic dopamine response immediately following a reward cue that encodes its expected value, and a sustained, ramping dopamine response that...

  7. Non-Ocular Circadian Oscillators and Photoreceptors Modulate Long Term Memory Formation in Aplysia

    OpenAIRE

    Lyons, Lisa C.; Rawashdeh, Oliver; Eskin, Arnold

    2006-01-01

    In Aplysia californica, memory formation for long-term sensitization (LTS) and for a more complex type of associative learning, learning that food is inedible (LFI), is modulated by a circadian clock. For both types of learning, formation of long-term memory occurs during the day and significantly less during the night. Aplysia eyes contain a well-characterized circadian oscillator that is strongly coupled to the locomotor activity rhythm. Thus, the authors hypothesized that the ocular circad...

  8. Studies Shed Light on Cross-modal Memory Facilitation of Fruit Flies

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ As a result of their threeyear studies in Drosophilae (fruit flies),CAS scientists reveal that the memory and learning in the insect could be enhanced by stimuli combining olfactory (or smell) and visual signals.

  9. When gestures show us the way: Co-speech gestures selectively facilitate navigation and spatial memory.

    OpenAIRE

    Galati, Alexia; Weisberg, Steven M.; Newcombe, Nora S.; Avraamides, Marios N.

    2017-01-01

    How does gesturing during route learning relate to subsequent spatial performance? We examined the relationship between gestures produced spontaneously while studying route directions and spatial representations of the navigated environment. Participants studied route directions, then navigated those routes from memory in a virtual environment, and finally had their memory of the environment assessed. We found that, for navigators with low spatial perspective-taking pe...

  10. Seeing iconic gestures while encoding events facilitates children's memory of these events

    OpenAIRE

    Aussems, Suzanne; Kita, Sotaro

    2017-01-01

    An experiment with 72 three-year-olds investigated whether encoding events while seeing iconic gestures boosts children's memory representation of these events. The events, shown in videos of actors moving in an unusual manner, were presented with either iconic gestures depicting how the actors performed these actions, interactive gestures, or no gesture. In a recognition memory task, children in the iconic gesture condition remembered actors and actions better than children in the control co...

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

    Science.gov (United States)

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

    2015-03-01

    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.

  12. Implicit memory formation during routine anesthesia in children: a double-masked randomized controlled trial.

    Science.gov (United States)

    Pham, Xiuzhi; Smith, Katherine R; Sheppard, Suzette J; Bradshaw, Carolyn; Lo, Eric; Davidson, Andrew J

    2010-05-01

    Implicit memory cannot be consciously recalled but may be revealed by changes in behavior. There is evidence for implicit memory formation during anesthesia in adults, but several studies in children have found no evidence for implicit memory. This may be due to insensitive testing. Also many of these tests were undertaken under controlled conditions. It remains unknown whether implicit memory is formed during routine pediatric anesthesia. The aim of this study was to determine whether there is evidence of implicit memory formation during routine anesthesia in children, using a degraded auditory stimulus recognition task. Three hundred and twelve children, aged 5-12 yr, were randomly assigned to be played either a sheep sound or white noise continuously through headphones during general anesthesia. No attempt was made to standardize the anesthetic. On recovery, children were played a sheep sound degraded by a white noise mask that progressively decreased over 60 s, with the outcome being the time taken to correctly recognize the sheep sound. Three hundred children completed the task. A comparison of the distribution of recognition times between the two groups found little evidence that exposure to a sheep sound during anesthesia was associated with postoperative time to recognition of a degraded sheep sound (hazard ratio 1.14, 95% CI of 0.90-1.43, P = 0.28). No implicit memory formation during routine anesthesia was demonstrated in children. It is increasingly likely that the potential clinical implications of implicit memory formation are less of a concern for pediatric anesthetists.

  13. Strong homeostatic TCR signals induce formation of self-tolerant virtual memory CD8 T cells.

    Science.gov (United States)

    Drobek, Ales; Moudra, Alena; Mueller, Daniel; Huranova, Martina; Horkova, Veronika; Pribikova, Michaela; Ivanek, Robert; Oberle, Susanne; Zehn, Dietmar; McCoy, Kathy D; Draber, Peter; Stepanek, Ondrej

    2018-05-11

    Virtual memory T cells are foreign antigen-inexperienced T cells that have acquired memory-like phenotype and constitute 10-20% of all peripheral CD8 + T cells in mice. Their origin, biological roles, and relationship to naïve and foreign antigen-experienced memory T cells are incompletely understood. By analyzing T-cell receptor repertoires and using retrogenic monoclonal T-cell populations, we demonstrate that the virtual memory T-cell formation is a so far unappreciated cell fate decision checkpoint. We describe two molecular mechanisms driving the formation of virtual memory T cells. First, virtual memory T cells originate exclusively from strongly self-reactive T cells. Second, the stoichiometry of the CD8 interaction with Lck regulates the size of the virtual memory T-cell compartment via modulating the self-reactivity of individual T cells. Although virtual memory T cells descend from the highly self-reactive clones and acquire a partial memory program, they are not more potent in inducing experimental autoimmune diabetes than naïve T cells. These data underline the importance of the variable level of self-reactivity in polyclonal T cells for the generation of functional T-cell diversity. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  14. Does stress remove the HDAC brakes for the formation and persistence of long-term memory?

    Science.gov (United States)

    White, André O; Wood, Marcelo A

    2014-07-01

    It has been known for numerous decades that gene expression is required for long-lasting forms of memory. In the past decade, the study of epigenetic mechanisms in memory processes has revealed yet another layer of complexity in the regulation of gene expression. Epigenetic mechanisms do not only provide complexity in the protein regulatory complexes that control coordinate transcription for specific cell function, but the epigenome encodes critical information that integrates experience and cellular history for specific cell functions as well. Thus, epigenetic mechanisms provide a unique mechanism of gene expression regulation for memory processes. This may be why critical negative regulators of gene expression, such as histone deacetylases (HDACs), have powerful effects on the formation and persistence of memory. For example, HDAC inhibition has been shown to transform a subthreshold learning event into robust long-term memory and also generate a form of long-term memory that persists beyond the point at which normal long-term memory fails. A key question that is explored in this review, from a learning and memory perspective, is whether stress-dependent signaling drives the formation and persistence of long-term memory via HDAC-dependent mechanisms. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Does stress remove the HDAC brakes for the formation and persistence of long-term memory?

    Science.gov (United States)

    White, André O.; Wood, Marcelo A.

    2013-01-01

    It has been known for numerous decades that gene expression is required for long-lasting forms of memory. In the past decade, the study of epigenetic mechanisms in memory processes has revealed yet another layer of complexity in the regulation of gene expression. Epigenetic mechanisms do not only provide complexity in the protein regulatory complexes that control coordinate transcription for specific cell function, but the epigenome encodes critical information that integrates experience and cellular history for specific cell functions as well. Thus, epigenetic mechanisms provide a unique mechanism of gene expression regulation for memory processes. This may be why critical negative regulators of gene expression, such as histone deacetylases (HDACs), have powerful effects on the formation and persistence of memory. For example, HDAC inhibition has been shown to transform a subthreshold learning event into robust long-term memory and also generate a form of long-term memory that persists beyond the point at which normal long-term memory fails. A key question that is explored in this review, from a learning and memory perspective, is whether stress-dependent signaling drives the formation and persistence of long-term memory via HDAC-dependent mechanisms. PMID:24149059

  16. Stress in the zoo: Tracking the impact of stress on memory formation over time.

    Science.gov (United States)

    Vogel, Susanne; Schwabe, Lars

    2016-09-01

    Although stress is well known to modulate human memory, precisely how memory formation is altered by a stressful encounter remains unclear. Stress effects on cognition are mainly mediated by the rapidly acting sympathetic nervous system, resulting in the release of catecholamines, and the slower acting hypothalamus-pituitary-adrenal axis secreting cortisol, which induces its effects on cognition through fast, non-genomic actions and delayed, genomic actions. Importantly, these different waves of the physiological stress response are thought to dynamically alter neural processing in brain regions important for memory such as the amygdala and the hippocampus. However, the precise time course of stress effects on memory formation is still unclear. To track the development of stress effects on memory over time, we tested individuals who underwent a stressful experience or a control procedure before a 2-h walk through a zoo, while an automatic camera continuously photographed the events they encoded. In a recognition memory test one week later, participants were presented with target photographs of their own zoo tour and lure photographs from an alternate tour. Stressed participants showed better memory for the experimental treatment than control participants, and this memory enhancement for the stressful encounter itself was directly linked to the sympathetic stress response. Moreover, stress enhanced memory for events encoded 41-65min after stressor onset, which was associated with the cortisol stress response, most likely arising from non-genomic cortisol actions. However, memory for events encoded long after the stressor, when genomic cortisol actions had most likely developed, remained unchanged. Our findings provide novel insights into how stress effects on memory formation develop over time, depending on the activity of major physiological stress response systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Interactivity and Explicit Memory Formation of Consumer Undergraduate Male Students on Internet Environment

    Directory of Open Access Journals (Sweden)

    George Bedinelli Rossi

    2016-01-01

    Full Text Available ABSTRACT This research aims to integrate the theories of Explicit Memory and Interactivity, contributing to the theoretical development of both. We investigated whether the interactivity precedes the explicit consumer memory. Data collection was carried on by sending online questionnaire to 876 undergraduate male students, with a return of 453 valid questionnaires. Data were analyzed using Structural Equation Modeling of the constructs Explicit Memory and Interactivity. The analyzes indicate that interactivity increases explicit consumer memory, filling a theoretical gap of this concept about its effects. Moreover, it is a concept related to the future, not only to the past and to present, as shown by the classical definitions. As for explicit memory, its formation results from the individual's interactions with the environment, which was not explained by classical theories. The results indicated that interactivity and explicit memory are almost independent of each other, having low correlation or almost nil.

  18. Silver nanoparticles alter learning and memory formation in an aquatic organism, Lymnaea stagnalis.

    Science.gov (United States)

    Young, Austin; Protheroe, Amy; Lukowiak, Ken

    2017-06-01

    We tested the effect of silver nanoparticles (AgNPs) on the ability of the pond snail, Lymnaea stagnalis, to learn and form long-term memory (LTM) following operant conditioning of aerial respiration. We hypothesized that the AgNPs would act as a stressor and prevent learning and LTM formation. We tested snails exposed for either 72 h or only during training and testing for memory (i.e. 0.5 h) and found no difference between those treatments. We found that at a low concentration of AgNPs (5 μg/L) neither learning and nor memory formation were altered. When we increased the concentration of AgNPs (10 μg/L) we found that memory formation was enhanced. Finally, at a higher concentration (50 μg/L) memory formation was blocked. To determine if the disassociation of Ag + from the AgNPs caused the effects on memory we performed similar experiments with AgNO 3 and found similar concentration-dependent results. Finally, we found that snails perceive the AgNPs differently from Ag+ as there was context specific memory. That is, snails trained in AgNPs did not show memory when tested in Ag + and vice-versa. We believe that changes in memory formation may be a more sensitive determination of AgNPs on aquatic organisms than the determination of a LC 50 . Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  19. Infralimbic dopamine D2 receptors mediate glucocorticoid-induced facilitation of auditory fear memory extinction in rats.

    Science.gov (United States)

    Dadkhah, Masoumeh; Abdullahi, Payman Raise; Rashidy-Pour, Ali; Sameni, Hamid Reza; Vafaei, Abbas Ali

    2018-03-01

    The infralimbic (IL) cortex of the medial prefrontal cortex plays an important role in the extinction of fear memory. Also, it has been showed that both brain glucocorticoid and dopamine receptors are involved in many processes such as fear extinction that drive learning and memory; however, the interaction of these receptors in the IL cortex remains unclear. We examined a putative interaction between the effects of glucocorticoid and dopamine receptors stimulation in the IL cortex on fear memory extinction in an auditory fear conditioning paradigm in male rats. Corticosterone (the endogenous glucocorticoid receptor ligand), or RU38486 (the synthetic glucocorticoid receptor antagonist) microinfusion into the IL cortex 10 min before test 1 attenuated auditory fear expression at tests 1-3, suggesting as an enhancement of fear extinction. The effect of corticosterone, but not RU38486 was counteracted by the dopamine D2 receptor antagonist sulpiride pre-treatment administered into the IL (at a dose that failed to alter freezing behavior on its own). In contrast, intra-IL infusion of the dopamine D1 receptor antagonist SCH23390 pre-treatment failed to alter freezing behavior. These findings provide evidence for the involvement of the IL cortex D2 receptors in CORT-induced facilitation of fear memory extinction. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Prenatal complex rhythmic music sound stimulation facilitates postnatal spatial learning but transiently impairs memory in the domestic chick.

    Science.gov (United States)

    Kauser, H; Roy, S; Pal, A; Sreenivas, V; Mathur, R; Wadhwa, S; Jain, S

    2011-01-01

    Early experience has a profound influence on brain development, and the modulation of prenatal perceptual learning by external environmental stimuli has been shown in birds, rodents and mammals. In the present study, the effect of prenatal complex rhythmic music sound stimulation on postnatal spatial learning, memory and isolation stress was observed. Auditory stimulation with either music or species-specific sounds or no stimulation (control) was provided to separate sets of fertilized eggs from day 10 of incubation. Following hatching, the chicks at age 24, 72 and 120 h were tested on a T-maze for spatial learning and the memory of the learnt task was assessed 24 h after training. In the posthatch chicks at all ages, the plasma corticosterone levels were estimated following 10 min of isolation. The chicks of all ages in the three groups took less (p memory after 24 h of training, only the music-stimulated chicks at posthatch age 24 h took a significantly longer (p music sounds facilitates spatial learning, though the music stimulation transiently impairs postnatal memory. 2011 S. Karger AG, Basel.

  1. Syntactic Recursion Facilitates and Working Memory Predicts Recursive Theory of Mind.

    Directory of Open Access Journals (Sweden)

    Burcu Arslan

    Full Text Available In this study, we focus on the possible roles of second-order syntactic recursion and working memory in terms of simple and complex span tasks in the development of second-order false belief reasoning. We tested 89 Turkish children in two age groups, one younger (4;6-6;5 years and one older (6;7-8;10 years. Although second-order syntactic recursion is significantly correlated with the second-order false belief task, results of ordinal logistic regressions revealed that the main predictor of second-order false belief reasoning is complex working memory span. Unlike simple working memory and second-order syntactic recursion tasks, the complex working memory task required processing information serially with additional reasoning demands that require complex working memory strategies. Based on our results, we propose that children's second-order theory of mind develops when they have efficient reasoning rules to process embedded beliefs serially, thus overcoming a possible serial processing bottleneck.

  2. Syntactic Recursion Facilitates and Working Memory Predicts Recursive Theory of Mind

    Science.gov (United States)

    Arslan, Burcu; Hohenberger, Annette; Verbrugge, Rineke

    2017-01-01

    In this study, we focus on the possible roles of second-order syntactic recursion and working memory in terms of simple and complex span tasks in the development of second-order false belief reasoning. We tested 89 Turkish children in two age groups, one younger (4;6–6;5 years) and one older (6;7–8;10 years). Although second-order syntactic recursion is significantly correlated with the second-order false belief task, results of ordinal logistic regressions revealed that the main predictor of second-order false belief reasoning is complex working memory span. Unlike simple working memory and second-order syntactic recursion tasks, the complex working memory task required processing information serially with additional reasoning demands that require complex working memory strategies. Based on our results, we propose that children’s second-order theory of mind develops when they have efficient reasoning rules to process embedded beliefs serially, thus overcoming a possible serial processing bottleneck. PMID:28072823

  3. Autoradiographic study of serotonin transporter during memory formation.

    Science.gov (United States)

    Tellez, Ruth; Rocha, Luisa; Castillo, Carlos; Meneses, Alfredo

    2010-09-01

    Serotonin transporter (SERT) has been associated with drugs of abuse like d-methamphetamine (METH). METH is well known to produce effects on the monoamine systems but it is unclear how METH affects SERT and memory. Here the effects of METH and the serotonin reuptake inhibitor fluoxetine (FLX) on autoshaping and novel object recognition (NOR) were investigated. Notably, both memory tasks recruit different behavioral, neural and cognitive demand. In autoshaping task a dose-response curve for METH was determined. METH (1.0mg/kg) impaired short-term memory (STM; lasting less of 90min) in NOR and impaired both STM and long-term memory (LTM; lasting 24 and 48h) in autoshaping, indicating that METH had long-lasting effects in the latter task. A comparative autoradiography study of the relationship between the binding pattern of SERT in autoshaping new untrained vs. trained treated (METH, FLX, or both) animals was made. Considering that hemispheric dominance is important for LTM, hence right vs. left hemisphere of the brain was compared. Results showed that trained animals decreased cortical SERT binding relative to untrained ones. In untrained and trained treated animals with the amnesic dose (1.0mg/kg) of METH SERT binding in several areas including hippocampus and cortex decreased, more remarkably in the trained animals. In contrast, FLX improved memory, increased SERT binding, prevented the METH amnesic effect and re-established the SERT binding. In general, memory and amnesia seemed to make SERT more vulnerable to drugs effects. Copyright 2010 Elsevier B.V. All rights reserved.

  4. Uhrf2 deletion impairs the formation of hippocampus-dependent memory by changing the structure of the dentate gyrus.

    Science.gov (United States)

    Chen, Xiao-Rong; Sun, Shi-Cheng; Teng, Shuai-Wen; Li, Liang; Bie, Yi-Fan; Yu, Hui; Li, Da-Li; Chen, Zhe-Yu; Wang, Yue

    2018-03-01

    Ubiquitin-like with PHD and ring finger domains 2 (Uhrf2) is distributed in many brain regions, including the cortex and hippocampus. Decreased Uhrf2 expression is involved in neurodegenerative disease. A recent study showed Uhrf2 deletion impaired spatial memory; however, the mechanism remains elusive. In our study, we determined that Uhrf2 +/- and Uhrf2 -/- mice had significant learning and memory deficiencies in contextual fear conditioning (CFC) and the novel place recognition test but not in the novel object recognition test. Interestingly, there were no changes in the Uhrf2 protein levels in the hippocampus of C57BL6 mice after CFC training, which suggests Uhrf2 in adult mice may not be related to the formation of CFC long-term memory. Based on Nissl staining, Uhrf2 deletion caused neuropathological changes specifically in the crest of the dentate gyrus (DG), such as cell swelling, a vague outline and confused boundary; however, no changes were identified in the medial prefrontal cortex (mPFC). Transmission electron microscope assay further indicated a series of abnormal ultrastructure changes in neurons and glia in the DG crest. These results suggested that Uhrf2 deletion selectively blocked the development of the DG crest and impaired hippocampus-dependent learning and memory. Our study will facilitate a better understanding of the role of Uhrf2 protein in the central nervous system.

  5. The timing of associative memory formation: frontal lobe and anterior medial temporal lobe activity at associative binding predicts memory

    Science.gov (United States)

    Hales, J. B.

    2011-01-01

    The process of associating items encountered over time and across variable time delays is fundamental for creating memories in daily life, such as for stories and episodes. Forming associative memory for temporally discontiguous items involves medial temporal lobe structures and additional neocortical processing regions, including prefrontal cortex, parietal lobe, and lateral occipital regions. However, most prior memory studies, using concurrently presented stimuli, have failed to examine the temporal aspect of successful associative memory formation to identify when activity in these brain regions is predictive of associative memory formation. In the current study, functional MRI data were acquired while subjects were shown pairs of sequentially presented visual images with a fixed interitem delay within pairs. This design allowed the entire time course of the trial to be analyzed, starting from onset of the first item, across the 5.5-s delay period, and through offset of the second item. Subjects then completed a postscan recognition test for the items and associations they encoded during the scan and their confidence for each. After controlling for item-memory strength, we isolated brain regions selectively involved in associative encoding. Consistent with prior findings, increased regional activity predicting subsequent associative memory success was found in anterior medial temporal lobe regions of left perirhinal and entorhinal cortices and in left prefrontal cortex and lateral occipital regions. The temporal separation within each pair, however, allowed extension of these findings by isolating the timing of regional involvement, showing that increased response in these regions occurs during binding but not during maintenance. PMID:21248058

  6. Bacillus subtilis δ Factor Functions as a Transcriptional Regulator by Facilitating the Open Complex Formation.

    Science.gov (United States)

    Prajapati, Ranjit Kumar; Sengupta, Shreya; Rudra, Paulami; Mukhopadhyay, Jayanta

    2016-01-15

    Most bacterial RNA polymerases (RNAP) contain five conserved subunits, viz. 2α, β, β', and ω. However, in many Gram-positive bacteria, especially in fermicutes, RNAP is associated with an additional factor, called δ. For over three decades since its identification, it had been thought that δ functioned as a subunit of RNAP to enhance the level of transcripts by recycling RNAP. In support of the previous observations, we also find that δ is involved in recycling of RNAP by releasing the RNA from the ternary complex. We further show that δ binds to RNA and is able to recycle RNAP when the length of the nascent RNA reaches a critical length. However, in this work we decipher a new function of δ. Performing biochemical and mutational analysis, we show that Bacillus subtilis δ binds to DNA immediately upstream of the promoter element at A-rich sequences on the abrB and rrnB1 promoters and facilitates open complex formation. As a result, δ facilitates RNAP to initiate transcription in the second scale, compared with minute scale in the absence of δ. Using transcription assay, we show that δ-mediated recycling of RNAP cannot be the sole reason for the enhancement of transcript yield. Our observation that δ does not bind to RNAP holo enzyme but is required to bind to DNA upstream of the -35 promoter element for transcription activation suggests that δ functions as a transcriptional regulator. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. The interaction of working memory performance and episodic memory formation in patients with Korsakoff's amnesia

    NARCIS (Netherlands)

    Geldorp, B. van; Bergmann, H.C.; Robertson, J.; Wester, A.J.; Kessels, R.P.C.

    2012-01-01

    Both neuroimaging work and studies investigating amnesic patients have shown involvement of the medial temporal lobe during working memory tasks, especially when multiple items or features have to be associated. However, so far no study has examined the relationship between working memory and

  8. The interaction of working memory performance and episodic memory formation in patients with Korsakoff's amnesia.

    NARCIS (Netherlands)

    Geldorp, B. van; Bergmann, H.C.; Robertson, J.; Wester, A.J.; Kessels, R.P.C.

    2012-01-01

    Both neuroimaging work and studies investigating amnesic patients have shown involvement of the medial temporal lobe during working memory tasks, especially when multiple items or features have to be associated. However, so far no study has examined the relationship between working memory and

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

    Science.gov (United States)

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

    2015-01-01

    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.

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

    Science.gov (United States)

    2014-01-01

    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

  11. Positive feelings facilitate working memory and complex decision making among older adults.

    Science.gov (United States)

    Carpenter, Stephanie M; Peters, Ellen; Västfjäll, Daniel; Isen, Alice M

    2013-01-01

    The impact of induced mild positive feelings on working memory and complex decision making among older adults (aged 63-85) was examined. Participants completed a computer administered card task in which participants could win money if they chose from "gain" decks and lose money if they chose from "loss" decks. Individuals in the positive-feeling condition chose better than neutral-feeling participants and earned more money overall. Participants in the positive-feeling condition also demonstrated improved working-memory capacity. These effects of positive-feeling induction have implications for affect theory, as well as, potentially, practical implications for people of all ages dealing with complex decisions.

  12. Distinct Neural Mechanisms Mediate Olfactory Memory Formation at Different Timescales

    Science.gov (United States)

    McNamara, Ann Marie; Magidson, Phillip D.; Linster, Christiane; Wilson, Donald A.; Cleland, Thomas A.

    2008-01-01

    Habituation is one of the oldest forms of learning, broadly expressed across sensory systems and taxa. Here, we demonstrate that olfactory habituation induced at different timescales (comprising different odor exposure and intertrial interval durations) is mediated by different neural mechanisms. First, the persistence of habituation memory is…

  13. Perirhinal Cortex Muscarinic Receptor Blockade Impairs Taste Recognition Memory Formation

    Science.gov (United States)

    Gutierrez, Ranier; De la Cruz, Vanesa; Rodriguez-Ortiz, Carlos J.; Bermudez-Rattoni, Federico

    2004-01-01

    The relevance of perirhinal cortical cholinergic and glutamatergic neurotransmission for taste recognition memory and learned taste aversion was assessed by microinfusions of muscarinic (scopolamine), NMDA (AP-5), and AMPA (NBQX) receptor antagonists. Infusions of scopolamine, but not AP5 or NBQX, prevented the consolidation of taste recognition…

  14. Transient medial prefrontal perturbation reduces false memory formation

    NARCIS (Netherlands)

    Berkers, R.M.W.J.; Linden, M.H. van der; Almeida, R.F. de; Müller, N.C.J.; Bovy, L.; Dresler, M.; Morris, R.G.M.; Fernandez, G.S.E.

    2017-01-01

    Knowledge extracted across previous experiences, or schemas, benefit encoding and retention of congruent information. However, they can also reduce specificity and augment memory for semantically related, but false information. A demonstration of the latter is given by the Deese-Roediger-McDermott

  15. Transient medial prefrontal perturbation reduces false memory formation.

    Science.gov (United States)

    Berkers, Ruud M W J; van der Linden, Marieke; de Almeida, Rafael F; Müller, Nils C J; Bovy, Leonore; Dresler, Martin; Morris, Richard G M; Fernández, Guillén

    2017-03-01

    Knowledge extracted across previous experiences, or schemas, benefit encoding and retention of congruent information. However, they can also reduce specificity and augment memory for semantically related, but false information. A demonstration of the latter is given by the Deese-Roediger-McDermott (DRM) paradigm, where the studying of words that fit a common semantic schema are found to induce false memories for words that are congruent with the given schema, but were not studied. The medial prefrontal cortex (mPFC) has been ascribed the function of leveraging prior knowledge to influence encoding and retrieval, based on imaging and patient studies. Here, we used transcranial magnetic stimulation (TMS) to transiently perturb ongoing mPFC processing immediately before participants performed the DRM-task. We observed the predicted reduction in false recall of critical lures after mPFC perturbation, compared to two control groups, whereas veridical recall and recognition memory performance remained similar across groups. These data provide initial causal evidence for a role of the mPFC in biasing the assimilation of new memories and their consolidation as a function of prior knowledge. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. CREB binding protein is required for both short-term and long-term memory formation.

    Science.gov (United States)

    Chen, Guiquan; Zou, Xiaoyan; Watanabe, Hirotaka; van Deursen, Jan M; Shen, Jie

    2010-09-29

    CREB binding protein (CBP) is a transcriptional coactivator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated conditional knock-out (cKO) mice in which CBP is completely inactivated in excitatory neurons of the postnatal forebrain. Histological analysis revealed normal neuronal morphology and absence of age-dependent neuronal degeneration in the CBP cKO cerebral cortex. CBP cKO mice exhibited robust impairment in the formation of spatial, associative, and object-recognition memory. In addition to impaired long-term memory, CBP cKO mice also displayed deficits in short-term associative and object-recognition memory. Administration of a histone deacetylase inhibitor, trichostatin A, rescued the reduction of acetylated histones in the CBP cKO cortex but failed to rescue either short- or long-term memory deficits, suggesting that the memory impairment may not be caused by general reduction of histone acetyltransferase activity in CBP cKO mice. Further microarray and Western analysis showed decreased expression of calcium-calmodulin-dependent kinase isoforms and NMDA and AMPA receptor subunits in the cerebral cortex of CBP cKO mice. Collectively, these findings suggest a crucial role for CBP in the formation of both short- and long-term memory.

  17. A role for autophagy in long-term spatial memory formation in male rodents.

    Science.gov (United States)

    Hylin, Michael J; Zhao, Jing; Tangavelou, Karthikeyan; Rozas, Natalia S; Hood, Kimberly N; MacGowan, Jacalyn S; Moore, Anthony N; Dash, Pramod K

    2018-03-01

    A hallmark of long-term memory formation is the requirement for protein synthesis. Administration of protein synthesis inhibitors impairs long-term memory formation without influencing short-term memory. Rapamycin is a specific inhibitor of target of rapamycin complex 1 (TORC1) that has been shown to block protein synthesis and impair long-term memory. In addition to regulating protein synthesis, TORC1 also phosphorylates Unc-51-like autophagy activating kinase-1 (Ulk-1) to suppress autophagy. As autophagy can be activated by rapamycin (and rapamycin inhibits long-term memory), our aim was to test the hypothesis that autophagy inhibitors would enhance long-term memory. To examine if learning alters autophagosome number, we used male reporter mice carrying the GFP-LC3 transgene. Using these mice, we observed that training in the Morris water maze task increases the number of autophagosomes, a finding contrary to our expectations. For learning and memory studies, male Long Evans rats were used due to their relatively larger size (compared to mice), making it easier to perform intrahippocampal infusions in awake, moving animals. When the autophagy inhibitors 3-methyladenine (3-MA) or Spautin-1 were administered bilaterally into the hippocampii prior to training in the Morris water maze task, the drugs did not alter learning. In contrast, when memory was tested 24 hours later by a probe trial, significant impairments were observed. In addition, intrahippocampal infusion of an autophagy activator peptide (TAT-Beclin-1) improved long-term memory. These results indicate that autophagy is not necessary for learning, but is required for long-term memory formation. © 2017 Wiley Periodicals, Inc.

  18. Level of processing modulates the neural correlates of emotional memory formation

    Science.gov (United States)

    Ritchey, Maureen; LaBar, Kevin S.; Cabeza, Roberto

    2010-01-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study employed a levels-of-processing manipulation to characterize the impact of emotion on encoding with and without the influence of elaborative processes. Participants viewed emotionally negative, neutral, and positive scenes under two conditions: a shallow condition focused on the perceptual features of the scenes and a deep condition that queried their semantic meaning. Recognition memory was tested 2 days later. Results showed that emotional memory enhancements were greatest in the shallow condition. FMRI analyses revealed that the right amygdala predicted subsequent emotional memory in the shallow more than deep condition, whereas the right ventrolateral prefrontal cortex demonstrated the reverse pattern. Furthermore, the association of these regions with the hippocampus was modulated by valence: the amygdala-hippocampal link was strongest for negative stimuli, whereas the prefrontal-hippocampal link was strongest for positive stimuli. Taken together, these results suggest two distinct activation patterns underlying emotional memory formation: an amygdala component that promotes memory during shallow encoding, especially for negative information, and a prefrontal component that provides extra benefits during deep encoding, especially for positive information. PMID:20350176

  19. Level of processing modulates the neural correlates of emotional memory formation.

    Science.gov (United States)

    Ritchey, Maureen; LaBar, Kevin S; Cabeza, Roberto

    2011-04-01

    Emotion is known to influence multiple aspects of memory formation, including the initial encoding of the memory trace and its consolidation over time. However, the neural mechanisms whereby emotion impacts memory encoding remain largely unexplored. The present study used a levels-of-processing manipulation to characterize the impact of emotion on encoding with and without the influence of elaborative processes. Participants viewed emotionally negative, neutral, and positive scenes under two conditions: a shallow condition focused on the perceptual features of the scenes and a deep condition that queried their semantic meaning. Recognition memory was tested 2 days later. Results showed that emotional memory enhancements were greatest in the shallow condition. fMRI analyses revealed that the right amygdala predicted subsequent emotional memory in the shallow more than deep condition, whereas the right ventrolateral PFC demonstrated the reverse pattern. Furthermore, the association of these regions with the hippocampus was modulated by valence: the amygdala-hippocampal link was strongest for negative stimuli, whereas the prefrontal-hippocampal link was strongest for positive stimuli. Taken together, these results suggest two distinct activation patterns underlying emotional memory formation: an amygdala component that promotes memory during shallow encoding, especially for negative information, and a prefrontal component that provides extra benefits during deep encoding, especially for positive information.

  20. Temporal binding function of dorsal CA1 is critical for declarative memory formation.

    Science.gov (United States)

    Sellami, Azza; Al Abed, Alice Shaam; Brayda-Bruno, Laurent; Etchamendy, Nicole; Valério, Stéphane; Oulé, Marie; Pantaléon, Laura; Lamothe, Valérie; Potier, Mylène; Bernard, Katy; Jabourian, Maritza; Herry, Cyril; Mons, Nicole; Piazza, Pier-Vincenzo; Eichenbaum, Howard; Marighetto, Aline

    2017-09-19

    Temporal binding, the process that enables association between discontiguous stimuli in memory, and relational organization, a process that enables the flexibility of declarative memories, are both hippocampus-dependent and decline in aging. However, how these two processes are related in supporting declarative memory formation and how they are compromised in age-related memory loss remain hypothetical. We here identify a causal link between these two features of declarative memory: Temporal binding is a necessary condition for the relational organization of discontiguous events. We demonstrate that the formation of a relational memory is limited by the capability of temporal binding, which depends on dorsal (d)CA1 activity over time intervals and diminishes in aging. Conversely, relational representation is successful even in aged individuals when the demand on temporal binding is minimized, showing that relational/declarative memory per se is not impaired in aging. Thus, bridging temporal intervals by dCA1 activity is a critical foundation of relational representation, and a deterioration of this mechanism is responsible for the age-associated memory impairment.

  1. Frazzled/DCC facilitates cardiac cell outgrowth and attachment during Drosophila dorsal vessel formation.

    Science.gov (United States)

    Macabenta, Frank D; Jensen, Amber G; Cheng, Yi-Shan; Kramer, Joseph J; Kramer, Sunita G

    2013-08-15

    Drosophila embryonic dorsal vessel (DV) morphogenesis is a highly stereotyped process that involves the migration and morphogenesis of 52 pairs of cardioblasts (CBs) in order to form a linear tube. This process requires spatiotemporally-regulated localization of signaling and adhesive proteins in order to coordinate the formation of a central lumen while maintaining simultaneous adhesion between CBs. Previous studies have shown that the Slit/Roundabout and Netrin/Unc5 repulsive signaling pathways facilitate site-specific loss of adhesion between contralateral CBs in order to form a luminal space. However, the concomitant mechanism by which attraction initiates CB outgrowth and discrete localization of adhesive proteins remains poorly understood. Here we provide genetic evidence that Netrin signals through DCC (Deleted in Colorectal Carcinoma)/UNC-40/Frazzled (Fra) to mediate CB outgrowth and attachment and that this function occurs prior to and independently of Netrin/UNC-5 signaling. fra mRNA is expressed in the CBs prior to and during DV morphogenesis. Loss-of-fra-function results in significant defects in cell shape and alignment between contralateral CB rows. In addition, CB outgrowth and attachment is impaired in both fra loss- and gain-of-function mutants. Deletion of both Netrin genes (NetA and NetB) results in CB attachment phenotypes similar to fra mutants. Similar defects are also seen when both fra and unc5 are deleted. Finally we show that Fra accumulates at dorsal and ventral leading edges of paired CBs, and this localization is dependent upon Netrin. We propose that while repulsive guidance mechanisms contribute to lumen formation by preventing luminal domains from coming together, site-specific Netrin/Frazzled signaling mediates CB attachment. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. Syntactic Recursion Facilitates and Working Memory Predicts Recursive Theory of Mind

    NARCIS (Netherlands)

    Arslan, Burcu; Hohenberger, Annette; Verbrugge, Rineke

    2017-01-01

    In this study, we focus on the possible roles of second-order syntactic recursion and working memory in terms of simple and complex span tasks in the development of second-order false belief reasoning. We tested 89 Turkish children in two age groups, one younger (4;6-6;5 years) and one older

  3. Proficient use of low spatial frequencies facilitates face memory but shows protracted maturation throughout adolescence

    NARCIS (Netherlands)

    Peters, Judith C; Kemner, Chantal

    2017-01-01

    Face perception is characterized by configural processing, which depends on visual information in the low spatial frequency (LSF) ranges. However, it is unclear whether LSF content is equally important for face memory. The present study investigated how face information in the low and high SF range

  4. Modality-specific Alpha Modulations Facilitate Long-term Memory Encoding in the Presence of Distracters

    NARCIS (Netherlands)

    Jiang, H.; Gerven, M.A.J. van; Jensen, O.

    2015-01-01

    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

  5. Modality-specific Alpha Modulations Facilitate Long-term Memory Encoding in the Presence of Distracters

    NARCIS (Netherlands)

    Jiang, H.; Gerven, M.A.J. van; Jensen, O.

    2014-01-01

    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

  6. The flavonol epicatechin reverses the suppressive effects of a stressor on long-term memory formation.

    Science.gov (United States)

    Knezevic, Bogdan; Lukowiak, Ken

    2014-11-15

    Learning and subsequent memory formation are influenced by both environmental and lifestyle factors, such as stress and diet. Epicatechin, a plant flavonol found in cocoa, red wine and green tea enhances long-term memory (LTM) formation in Lymnaea. By contrast, an ecologically relevant stressor, low-calcium pond water, suppresses LTM formation. We tested the hypothesis that epicatechin overcomes the suppressive effects of the stressor on LTM formation in the continued presence of the stressor. Snails trained in low-calcium pond water exhibit learning but not LTM. Epicatechin (15 mg l(-1)) in control pond water enhances LTM formation. When epicatechin was added to the low-calcium pond water an enhanced LTM similar to that seen in control pond water was observed. Thus, a naturally occurring bioactive plant compound was able to overcome the suppressive effects of an ecologically relevant stressor on LTM formation. © 2014. Published by The Company of Biologists Ltd.

  7. The differential role of cortical protein synthesis in taste memory formation and persistence

    Science.gov (United States)

    Levitan, David; Gal-Ben-Ari, Shunit; Heise, Christopher; Rosenberg, Tali; Elkobi, Alina; Inberg, Sharon; Sala, Carlo; Rosenblum, Kobi

    2016-05-01

    The current dogma suggests that the formation of long-term memory (LTM) is dependent on protein synthesis but persistence of the memory trace is not. However, many of the studies examining the effect of protein synthesis inhibitors (PSIs) on LTM persistence were performed in the hippocampus, which is known to have a time-dependent role in memory storage, rather than the cortex, which is considered to be the main structure to store long-term memories. Here we studied the effect of PSIs on LTM formation and persistence in male Wistar Hola (n⩾5) rats by infusing the protein synthesis inhibitor, anisomycin (100 μg, 1 μl), into the gustatory cortex (GC) during LTM formation and persistence in conditioned taste aversion (CTA). We found that local anisomycin infusion to the GC before memory acquisition impaired LTM formation (P=8.9E-5), but had no effect on LTM persistence when infused 3 days post acquisition (P=0.94). However, when we extended the time interval between treatment with anisomycin and testing from 3 days to 14 days, LTM persistence was enhanced (P=0.01). The enhancement was on the background of stable and non-declining memory, and was not recapitulated by another amnesic agent, APV (10 μg, 1 μl), an N-methyl-D-aspartate receptor antagonist (P=0.54). In conclusion, CTA LTM remains sensitive to the action of PSIs in the GC even 3 days following memory acquisition. This sensitivity is differentially expressed between the formation and persistence of LTM, suggesting that increased cortical protein synthesis promotes LTM formation, whereas decreased protein synthesis promotes LTM persistence.

  8. Disrupting Jagged1-Notch signaling impairs spatial memory formation in adult mice.

    Science.gov (United States)

    Sargin, Derya; Botly, Leigh C P; Higgs, Gemma; Marsolais, Alexander; Frankland, Paul W; Egan, Sean E; Josselyn, Sheena A

    2013-07-01

    It is well-known that Notch signaling plays a critical role in brain development and growing evidence implicates this signaling pathway in adult synaptic plasticity and memory formation. The Notch1 receptor is activated by two subclasses of ligands, Delta-like (including Dll1 and Dll4) and Jagged (including Jag1 and Jag2). Ligand-induced Notch1 receptor signaling is modulated by a family of Fringe proteins, including Lunatic fringe (Lfng). Although Dll1, Jag1 and Lfng are critical regulators of Notch signaling, their relative contribution to memory formation in the adult brain is unknown. To investigate the roles of these important components of Notch signaling in memory formation, we examined spatial and fear memory formation in adult mice with reduced expression of Dll1, Jag1, Lfng and Dll1 plus Lfng. We also examined motor activity, anxiety-like behavior and sensorimotor gating using the acoustic startle response in these mice. Of the lines of mutant mice tested, we found that only mice with reduced Jag1 expression (mice heterozygous for a null mutation in Jag1, Jag1(+/-)) showed a selective impairment in spatial memory formation. Importantly, all other behavior including open field activity, conditioned fear memory (both context and discrete cue), acoustic startle response and prepulse inhibition, was normal in this line of mice. These results provide the first in vivo evidence that Jag1-Notch signaling is critical for memory formation in the adult brain. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  9. Intermediate levels of hippocampal activity appear optimal for associative memory formation.

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    Full Text Available BACKGROUND: It is well established that hippocampal activity is positively related to effective associative memory formation. However, in biological systems often optimal levels of activity are contrasted by both sub- and supra-optimal levels. Sub-optimal levels of hippocampal activity are commonly attributed to unsuccessful memory formation, whereas the supra-optimal levels of hippocampal activity related to unsuccessful memory formation have been rarely studied. It is still unclear under what circumstances such supra-optimal levels of hippocampal activity occur. To clarify this issue, we aimed at creating a condition, in which supra-optimal hippocampal activity is associated with encoding failure. We assumed that such supra-optimal activity occurs when task-relevant information is embedded in task-irrelevant, distracting information, which can be considered as noise. METHODOLOGY/PRINCIPAL FINDINGS: In the present fMRI study, we probed neural correlates of associative memory formation in a full-factorial design with associative memory (subsequently remembered versus forgotten and noise (induced by high versus low distraction as factors. Results showed that encoding failure was associated with supra-optimal activity in the high-distraction condition and with sub-optimal activity in the low distraction condition. Thus, we revealed evidence for a bell-shape function relating hippocampal activity with associative encoding success. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that intermediate levels of hippocampal activity are optimal while both too low and too high levels appear detrimental for associative memory formation. Supra-optimal levels of hippocampal activity seem to occur when task-irrelevant information is added to task-relevant signal. If such task-irrelevant noise is reduced adequately, hippocampal activity is lower and thus optimal for associative memory formation.

  10. Emotional Memory Formation Under Lower Versus Higher Stress Conditions

    OpenAIRE

    Kogan, Inna; Richter-Levin, Gal

    2010-01-01

    An exposure to stress can enhance memory for emotionally arousing experiences. The phenomenon is suggested to be amygdala-dependent and in accordance with that view the amygdala was found to modulate mnemonic processes in other brain regions. Previously, we illustrated increased amygdala activation and reduced activation of CA1 following spatial learning under higher versus lower stress conditions. When spatial learning was followed by reversal training interference, impaired retention was de...

  11. Novelty processing and memory formation in Parkinson's disease.

    Science.gov (United States)

    Schomaker, J; Berendse, H W; Foncke, E M J; van der Werf, Y D; van den Heuvel, O A; Theeuwes, J; Meeter, M

    2014-09-01

    Parkinson's disease (PD) is characterized by a degeneration of nigrostriatal dopaminergic cells, resulting in dopamine depletion. This depletion is counteracted through dopamine replacement therapy (DRT). Dopamine has been suggested to affect novelty processing and memory, which suggests that these processes are also implicated in PD and that DRT could affect them. To investigate word learning and novelty processing in patients with PD as indexed by the P2 and P3 event-related potential components, and the role of DRT in these processes. 21 patients with PD and 21 matched healthy controls were included. Patients with PD were tested on and off DRT in two sessions in a counterbalanced design, and healthy controls were tested twice without intervention. Electroencephalogram (EEG) was measured while participants performed a word learning Von Restorff task. Healthy controls showed the typical Von Restorff effect, with better memory for words that were presented in novel fonts, than for words presented in standard font. Surprisingly, this effect was reversed in the patients with PD. In line with the behavioral findings, the P3 was larger for novel than for standard font words in healthy controls, but not in patients with PD. For both groups the P2 and P3 event-related components were larger for recalled versus forgotten words. DRT did not affect these processes. Learning of novel information is compromised in patients with PD. Likewise, the P2 and P3 components that predict successful memory encoding are reduced in PD patients. This was true both on and off DRT, suggesting that these findings reflect abnormalities in learning and memory in PD that are not resolved by dopaminergic medication. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Chronic transcranial focal stimulation from tripolar concentric ring electrodes does not disrupt memory formation in rats.

    Science.gov (United States)

    Luby, Matthew D; Makeyev, Oleksandr; Besio, Walter G

    2014-01-01

    Non-invasive electrical brain stimulation has shown potential utility as a treatment for seizures in epilepsy patients. Transcranial focal stimulation (TFS) via tripolar concentric ring electrodes (TCREs) has been effective in reducing seizure severity in acute rodent models, but it has yet to be determined whether or not it will serve as a viable long-term treatment strategy. Prior experiments indicate that a single dose of TFS via TCRE does not impact short- or long-term memory formation. The present study investigated if five daily doses of TFS via a TCRE on the scalp affected the memory. The spontaneous object recognition (SOR) test was used to evaluate the memory. Sham and TFS-treated groups were evaluated and both showed comparable levels of preference for novel objects, indicating successful memory formation. More work on repeated dosage strategies is important for establishing the safety and efficacy of TFS as a putative treatment.

  13. A simplified memory network model based on pattern formations

    Science.gov (United States)

    Xu, Kesheng; Zhang, Xiyun; Wang, Chaoqing; Liu, Zonghua

    2014-12-01

    Many experiments have evidenced the transition with different time scales from short-term memory (STM) to long-term memory (LTM) in mammalian brains, while its theoretical understanding is still under debate. To understand its underlying mechanism, it has recently been shown that it is possible to have a long-period rhythmic synchronous firing in a scale-free network, provided the existence of both the high-degree hubs and the loops formed by low-degree nodes. We here present a simplified memory network model to show that the self-sustained synchronous firing can be observed even without these two necessary conditions. This simplified network consists of two loops of coupled excitable neurons with different synaptic conductance and with one node being the sensory neuron to receive an external stimulus signal. This model can be further used to show how the diversity of firing patterns can be selectively formed by varying the signal frequency, duration of the stimulus and network topology, which corresponds to the patterns of STM and LTM with different time scales. A theoretical analysis is presented to explain the underlying mechanism of firing patterns.

  14. The full-length form of the Drosophila amyloid precursor protein is involved in memory formation.

    Science.gov (United States)

    Bourdet, Isabelle; Preat, Thomas; Goguel, Valérie

    2015-01-21

    The APP plays a central role in AD, a pathology that first manifests as a memory decline. Understanding the role of APP in normal cognition is fundamental in understanding the progression of AD, and mammalian studies have pointed to a role of secreted APPα in memory. In Drosophila, we recently showed that APPL, the fly APP ortholog, is required for associative memory. In the present study, we aimed to characterize which form of APPL is involved in this process. We show that expression of a secreted-APPL form in the mushroom bodies, the center for olfactory memory, is able to rescue the memory deficit caused by APPL partial loss of function. We next assessed the impact on memory of the Drosophila α-secretase kuzbanian (KUZ), the enzyme initiating the nonamyloidogenic pathway that produces secreted APPLα. Strikingly, KUZ overexpression not only failed to rescue the memory deficit caused by APPL loss of function, it exacerbated this deficit. We further show that in addition to an increase in secreted-APPL forms, KUZ overexpression caused a decrease of membrane-bound full-length species that could explain the memory deficit. Indeed, we observed that transient expression of a constitutive membrane-bound mutant APPL form is sufficient to rescue the memory deficit caused by APPL reduction, revealing for the first time a role of full-length APPL in memory formation. Our data demonstrate that, in addition to secreted APPL, the noncleaved form is involved in memory, raising the possibility that secreted and full-length APPL act together in memory processes. Copyright © 2015 the authors 0270-6474/15/351043-09$15.00/0.

  15. Synaptic scaling enables dynamically distinct short- and long-term memory formation.

    Directory of Open Access Journals (Sweden)

    Christian Tetzlaff

    2013-10-01

    Full Text Available Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

  16. Synaptic scaling enables dynamically distinct short- and long-term memory formation.

    Science.gov (United States)

    Tetzlaff, Christian; Kolodziejski, Christoph; Timme, Marc; Tsodyks, Misha; Wörgötter, Florentin

    2013-10-01

    Memory storage in the brain relies on mechanisms acting on time scales from minutes, for long-term synaptic potentiation, to days, for memory consolidation. During such processes, neural circuits distinguish synapses relevant for forming a long-term storage, which are consolidated, from synapses of short-term storage, which fade. How time scale integration and synaptic differentiation is simultaneously achieved remains unclear. Here we show that synaptic scaling - a slow process usually associated with the maintenance of activity homeostasis - combined with synaptic plasticity may simultaneously achieve both, thereby providing a natural separation of short- from long-term storage. The interaction between plasticity and scaling provides also an explanation for an established paradox where memory consolidation critically depends on the exact order of learning and recall. These results indicate that scaling may be fundamental for stabilizing memories, providing a dynamic link between early and late memory formation processes.

  17. Rapid formation and flexible expression of memories of subliminal word pairs.

    Science.gov (United States)

    Reber, Thomas P; Henke, Katharina

    2011-01-01

    Our daily experiences are incidentally and rapidly encoded as episodic memories. Episodic memories consist of numerous associations (e.g., who gave what to whom where and when) that can be expressed flexibly in new situations. Key features of episodic memory are speed of encoding, its associative nature, and its representational flexibility. Another defining feature of human episodic memory has been consciousness of encoding/retrieval. Here, we show that humans can rapidly form associations between subliminal words and minutes later retrieve these associations even if retrieval words were conceptually related to, but different from encoding words. Because encoding words were presented subliminally, associative encoding, and retrieval were unconscious. Unconscious association formation and retrieval were dependent on a preceding understanding of task principles. We conclude that key computations underlying episodic memory - rapid encoding and flexible expression of associations - can operate outside consciousness.

  18. Facilitating role of 3D multimodal visualization and learning rehearsal in memory recall.

    Science.gov (United States)

    Do, Phuong T; Moreland, John R

    2014-04-01

    The present study investigated the influence of 3D multimodal visualization and learning rehearsal on memory recall. Participants (N = 175 college students ranging from 21 to 25 years) were assigned to different training conditions and rehearsal processes to learn a list of 14 terms associated with construction of a wood-frame house. They then completed a memory test determining their cognitive ability to free recall the definitions of the 14 studied terms immediately after training and rehearsal. The audiovisual modality training condition was associated with the highest accuracy, and the visual- and auditory-modality conditions with lower accuracy rates. The no-training condition indicated little learning acquisition. A statistically significant increase in performance accuracy for the audiovisual condition as a function of rehearsal suggested the relative importance of rehearsal strategies in 3D observational learning. Findings revealed the potential application of integrating virtual reality and cognitive sciences to enhance learning and teaching effectiveness.

  19. Extinction memory is facilitated by methylphenidate and regulated by dopamine and noradrenaline receptors.

    Science.gov (United States)

    Furini, Cristiane R G; Behling, Jonny A K; Zinn, Carolina G; Zanini, Mara Lise; Assis Brasil, Eduardo; Pereira, Luiza Doro; Izquierdo, Ivan; de Carvalho Myskiw, Jociane

    2017-05-30

    Extinction is defined as the learned inhibition of retrieval and is the mainstay of exposure therapy, which is widely used to treat drug addiction, phobias and fear disorders. The psychostimulant, methylphenidate (MPH) is known to increase extracellular levels of noradrenaline and dopamine by blocking their reuptake and studies have demonstrated that MPH can modulate hippocampal physiology and/or functions including long-term potentiation (LTP), learning and memory. However, the influence of MPH on fear extinction memory has been insufficiently studied. Here we investigate the effect of MPH infused into the CA1 region of the hippocampus on extinction memory in animals normally incapable of showing contextual fear conditioning (CFC) extinction because of weak training, and the possible mechanisms through which it acts during this process. For this, male Wistar rats with infusion cannulae stereotaxically implanted in the CA1 region were submitted to a weak extinction protocol in a CFC apparatus. Animals that received intra-CA1 infusion of MPH (12.5μg/side) 20min before the extinction training (Ext Tr) expressed less freezing behavior than Veh-treated animals during both Ext Tr and extinction retention Test (Ext Test). Additionally, the administration of MPH+Timolol (1μg/side) or MPH+SCH23390 (1.5μg/side) intra-CA1 20min before the Ext Tr blocked the enhancing effect of the MPH on extinction learning. These results suggest that MPH in the CA1 region of the hippocampus is able to induce the consolidation of extinction memory and this process occurs through both β-adrenergic and D1/D5 dopaminergic receptors. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Motivational valence alters memory formation without altering exploration of a real-life spatial environment.

    Science.gov (United States)

    Chiew, Kimberly S; Hashemi, Jordan; Gans, Lee K; Lerebours, Laura; Clement, Nathaniel J; Vu, Mai-Anh T; Sapiro, Guillermo; Heller, Nicole E; Adcock, R Alison

    2018-01-01

    Volitional exploration and learning are key to adaptive behavior, yet their characterization remains a complex problem for cognitive science. Exploration has been posited as a mechanism by which motivation promotes memory, but this relationship is not well-understood, in part because novel stimuli that motivate exploration also reliably elicit changes in neuromodulatory brain systems that directly alter memory formation, via effects on neural plasticity. To deconfound interrelationships between motivation, exploration, and memory formation we manipulated motivational state prior to entering a spatial context, measured exploratory responses to the context and novel stimuli within it, and then examined motivation and exploration as predictors of memory outcomes. To elicit spontaneous exploration, we used the physical space of an art exhibit with affectively rich content; we expected motivated exploration and memory to reflect multiple factors, including not only motivational valence, but also individual differences. Motivation was manipulated via an introductory statement framing exhibit themes in terms of Promotion- or Prevention-oriented goals. Participants explored the exhibit while being tracked by video. They returned 24 hours later for recall and spatial memory tests, followed by measures of motivation, personality, and relevant attitude variables. Promotion and Prevention condition participants did not differ in terms of group-level exploration time or memory metrics, suggesting similar motivation to explore under both framing contexts. However, exploratory behavior and memory outcomes were significantly more closely related under Promotion than Prevention, indicating that Prevention framing disrupted expected depth-of-encoding effects. Additionally, while trait measures predicted exploration similarly across framing conditions, traits interacted with motivational framing context and facial affect to predict memory outcomes. This novel characterization of

  1. Motivational valence alters memory formation without altering exploration of a real-life spatial environment.

    Directory of Open Access Journals (Sweden)

    Kimberly S Chiew

    Full Text Available Volitional exploration and learning are key to adaptive behavior, yet their characterization remains a complex problem for cognitive science. Exploration has been posited as a mechanism by which motivation promotes memory, but this relationship is not well-understood, in part because novel stimuli that motivate exploration also reliably elicit changes in neuromodulatory brain systems that directly alter memory formation, via effects on neural plasticity. To deconfound interrelationships between motivation, exploration, and memory formation we manipulated motivational state prior to entering a spatial context, measured exploratory responses to the context and novel stimuli within it, and then examined motivation and exploration as predictors of memory outcomes. To elicit spontaneous exploration, we used the physical space of an art exhibit with affectively rich content; we expected motivated exploration and memory to reflect multiple factors, including not only motivational valence, but also individual differences. Motivation was manipulated via an introductory statement framing exhibit themes in terms of Promotion- or Prevention-oriented goals. Participants explored the exhibit while being tracked by video. They returned 24 hours later for recall and spatial memory tests, followed by measures of motivation, personality, and relevant attitude variables. Promotion and Prevention condition participants did not differ in terms of group-level exploration time or memory metrics, suggesting similar motivation to explore under both framing contexts. However, exploratory behavior and memory outcomes were significantly more closely related under Promotion than Prevention, indicating that Prevention framing disrupted expected depth-of-encoding effects. Additionally, while trait measures predicted exploration similarly across framing conditions, traits interacted with motivational framing context and facial affect to predict memory outcomes. This novel

  2. Motivational valence alters memory formation without altering exploration of a real-life spatial environment

    Science.gov (United States)

    Hashemi, Jordan; Gans, Lee K.; Lerebours, Laura; Clement, Nathaniel J.; Vu, Mai-Anh T.; Sapiro, Guillermo; Heller, Nicole E.; Adcock, R. Alison

    2018-01-01

    Volitional exploration and learning are key to adaptive behavior, yet their characterization remains a complex problem for cognitive science. Exploration has been posited as a mechanism by which motivation promotes memory, but this relationship is not well-understood, in part because novel stimuli that motivate exploration also reliably elicit changes in neuromodulatory brain systems that directly alter memory formation, via effects on neural plasticity. To deconfound interrelationships between motivation, exploration, and memory formation we manipulated motivational state prior to entering a spatial context, measured exploratory responses to the context and novel stimuli within it, and then examined motivation and exploration as predictors of memory outcomes. To elicit spontaneous exploration, we used the physical space of an art exhibit with affectively rich content; we expected motivated exploration and memory to reflect multiple factors, including not only motivational valence, but also individual differences. Motivation was manipulated via an introductory statement framing exhibit themes in terms of Promotion- or Prevention-oriented goals. Participants explored the exhibit while being tracked by video. They returned 24 hours later for recall and spatial memory tests, followed by measures of motivation, personality, and relevant attitude variables. Promotion and Prevention condition participants did not differ in terms of group-level exploration time or memory metrics, suggesting similar motivation to explore under both framing contexts. However, exploratory behavior and memory outcomes were significantly more closely related under Promotion than Prevention, indicating that Prevention framing disrupted expected depth-of-encoding effects. Additionally, while trait measures predicted exploration similarly across framing conditions, traits interacted with motivational framing context and facial affect to predict memory outcomes. This novel characterization of

  3. Event-related brain potential correlates of human auditory sensory memory-trace formation.

    Science.gov (United States)

    Haenschel, Corinna; Vernon, David J; Dwivedi, Prabuddh; Gruzelier, John H; Baldeweg, Torsten

    2005-11-09

    The event-related potential (ERP) component mismatch negativity (MMN) is a neural marker of human echoic memory. MMN is elicited by deviant sounds embedded in a stream of frequent standards, reflecting the deviation from an inferred memory trace of the standard stimulus. The strength of this memory trace is thought to be proportional to the number of repetitions of the standard tone, visible as the progressive enhancement of MMN with number of repetitions (MMN memory-trace effect). However, no direct ERP correlates of the formation of echoic memory traces are currently known. This study set out to investigate changes in ERPs to different numbers of repetitions of standards, delivered in a roving-stimulus paradigm in which the frequency of the standard stimulus changed randomly between stimulus trains. Normal healthy volunteers (n = 40) were engaged in two experimental conditions: during passive listening and while actively discriminating changes in tone frequency. As predicted, MMN increased with increasing number of standards. However, this MMN memory-trace effect was caused mainly by enhancement with stimulus repetition of a slow positive wave from 50 to 250 ms poststimulus in the standard ERP, which is termed here "repetition positivity" (RP). This RP was recorded from frontocentral electrodes when participants were passively listening to or actively discriminating changes in tone frequency. RP may represent a human ERP correlate of rapid and stimulus-specific adaptation, a candidate neuronal mechanism underlying sensory memory formation in the auditory cortex.

  4. The human hippocampal formation mediates short-term memory of colour-location associations.

    Science.gov (United States)

    Finke, Carsten; Braun, Mischa; Ostendorf, Florian; Lehmann, Thomas-Nicolas; Hoffmann, Karl-Titus; Kopp, Ute; Ploner, Christoph J

    2008-01-31

    The medial temporal lobe (MTL) has long been considered essential for declarative long-term memory, whereas the fronto-parietal cortex is generally seen as the anatomical substrate of short-term memory. This traditional dichotomy is questioned by recent studies suggesting a possible role of the MTL for short-term memory. In addition, there is no consensus on a possible specialization of MTL sub-regions for memory of associative information. Here, we investigated short-term memory for single features and feature associations in three humans with post-surgical lesions affecting the right hippocampal formation and in 10 healthy controls. We used three delayed-match-to-sample tasks with two delays (900/5000 ms) and three set sizes (2/4/6 items). Subjects were instructed to remember either colours, locations or colour-location associations. In colour-only and location-only conditions, performance of patients did not differ from controls. By contrast, a significant group difference was found in the association condition at 5000 ms delay. This difference was largely independent of set size, thus suggesting that it cannot be explained by the increased complexity of the association condition. These findings show that the hippocampal formation plays a significant role for short-term memory of simple visuo-spatial associations, and suggest a specialization of MTL sub-regions for associative memory.

  5. Entrainment of prefrontal beta oscillations induces an endogenous echo and impairs memory formation.

    Science.gov (United States)

    Hanslmayr, Simon; Matuschek, Jonas; Fellner, Marie-Christin

    2014-04-14

    Brain oscillations across all frequency bands play a key role for memory formation. Specifically, desynchronization of local neuronal assemblies in the left inferior prefrontal cortex (PFC) in the beta frequency (∼18 Hz) has been shown to be central for encoding of verbal memories. However, it remains elusive whether prefrontal beta desynchronization is causally relevant for memory formation and whether these endogenous beta oscillations can be entrained by external stimulation. By using combined EEG-TMS (transcranial magnetic stimulation), we here address these fundamental questions in human participants performing a word-list learning task. Confirming our predictions, memory encoding was selectively impaired when the left inferior frontal gyrus (IFG) was driven at beta (18.7 Hz) compared to stimulation at other frequencies (6.8 Hz and 10.7 Hz) and to ineffective sham stimulation (18.7 Hz). Furthermore, a sustained oscillatory "echo" in the left IFG, which outlasted the stimulation period by approximately 1.5 s, was observed solely after beta stimulation. The strength of this beta echo was related to memory impairment on a between-subjects level. These results show endogenous oscillatory entrainment effects and behavioral impairment selectively in beta frequency for stimulation of the left IFG, demonstrating an intimate causal relationship between prefrontal beta desynchronization and memory formation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Roles of NO signaling in long-term memory formation in visual learning in an insect.

    Directory of Open Access Journals (Sweden)

    Yukihisa Matsumoto

    Full Text Available Many insects exhibit excellent capability of visual learning, but the molecular and neural mechanisms are poorly understood. This is in contrast to accumulation of information on molecular and neural mechanisms of olfactory learning in insects. In olfactory learning in insects, it has been shown that cyclic AMP (cAMP signaling critically participates in the formation of protein synthesis-dependent long-term memory (LTM and, in some insects, nitric oxide (NO-cyclic GMP (cGMP signaling also plays roles in LTM formation. In this study, we examined the possible contribution of NO-cGMP signaling and cAMP signaling to LTM formation in visual pattern learning in crickets. Crickets that had been subjected to 8-trial conditioning to associate a visual pattern with water reward exhibited memory retention 1 day after conditioning, whereas those subjected to 4-trial conditioning exhibited 30-min memory retention but not 1-day retention. Injection of cycloheximide, a protein synthesis inhibitor, into the hemolymph prior to 8-trial conditioning blocked formation of 1-day memory, whereas it had no effect on 30-min memory formation, indicating that 1-day memory can be characterized as protein synthesis-dependent long-term memory (LTM. Injection of an inhibitor of the enzyme producing an NO or cAMP prior to 8-trial visual conditioning blocked LTM formation, whereas it had no effect on 30-min memory formation. Moreover, injection of an NO donor, cGMP analogue or cAMP analogue prior to 4-trial conditioning induced LTM. Induction of LTM by an NO donor was blocked by DDA, an inhibitor of adenylyl cyclase, an enzyme producing cAMP, but LTM induction by a cAMP analogue was not impaired by L-NAME, an inhibitor of NO synthase. The results indicate that cAMP signaling is downstream of NO signaling for visual LTM formation. We conclude that visual learning and olfactory learning share common biochemical cascades for LTM formation.

  7. Do Illustrations Enhance Preschoolers' Memories for Stories? Age-Related Change in the Picture Facilitation Effect

    Science.gov (United States)

    Greenhoot, Andrea Follmer; Semb, Patricia A.

    2008-01-01

    This study investigated whether illustrations facilitate story recall in preschoolers (N = 58) 46 to 63 months of age. Each child was exposed to either a verbal story narrative with illustrations (Verbal and Picture condition), the narrative alone (Verbal Only condition), the narrative with uninformative illustrations (Verbal and Irrelevant…

  8. Type II membrane protein CD69 regulates the formation of resting T-helper memory.

    Science.gov (United States)

    Shinoda, Kenta; Tokoyoda, Koji; Hanazawa, Asami; Hayashizaki, Koji; Zehentmeier, Sandra; Hosokawa, Hiroyuki; Iwamura, Chiaki; Koseki, Haruhiko; Tumes, Damon J; Radbruch, Andreas; Nakayama, Toshinori

    2012-05-08

    Memory T-helper (Th) lymphocytes are crucial for the maintenance of acquired immunity to eliminate infectious pathogens. We have previously demonstrated that most memory Th lymphocytes reside and rest on stromal niches of the bone marrow (BM). Little is known, however, regarding the molecular basis for the generation and maintenance of BM memory Th lymphocytes. Here we show that CD69-deficient effector CD4 T lymphocytes fail to relocate into and persist in the BM and therefore to differentiate into memory cells. Consequently, CD69-deficient CD4 T cells fail to facilitate the production of high-affinity antibodies and the generation of BM long-lived plasma cells in the late phase of immune responses. Thus, CD69 is critical for the generation and maintenance of professional memory Th lymphocytes, which can efficiently help humoral immunity in the late phase. The deficit of immunological memory in CD69-deficient mice also highlights the essential role of BM for the establishment of Th memory.

  9. Differential requirement of de novo Arc protein synthesis in the insular cortex and the amygdala for safe and aversive taste long-term memory formation.

    Science.gov (United States)

    Guzmán-Ramos, Kioko; Venkataraman, Archana; Morin, Jean-Pascal; Osorio-Gómez, Daniel; Bermúdez-Rattoni, Federico

    2018-04-16

    Several immediate early genes products are known to be involved in the facilitation of structural and functional modifications at distinct synapses activated through experience. The IEG-encoded protein Arc (activity regulated cytoskeletal-associated protein) has been widely implicated in long-term memory formation and stabilization. In this study, we sought to evaluate a possible role for de novo Arc protein synthesis in the insular cortex (IC) and in the amygdala (AMY) during long-term taste memory formation. We found that acute inhibition of Arc protein synthesis through the infusion of antisense oligonucleotides administered in the IC before a novel taste presentation, affected consolidation of a safe taste memory trace (ST) but spared consolidation of conditioned taste aversion (CTA). Conversely, blocking Arc synthesis within the AMY impaired CTA consolidation but had no effect on ST long-term memory formation. Our results suggest that Arc-dependent plasticity during taste learning is required within distinct structures of the medial temporal lobe, depending on the emotional valence of the memory trace. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. Oxytocin selectively facilitates learning with social feedback and increases activity and functional connectivity in emotional memory and reward processing regions.

    Science.gov (United States)

    Hu, Jiehui; Qi, Song; Becker, Benjamin; Luo, Lizhu; Gao, Shan; Gong, Qiyong; Hurlemann, René; Kendrick, Keith M

    2015-06-01

    In male Caucasian subjects, learning is facilitated by receipt of social compared with non-social feedback, and the neuropeptide oxytocin (OXT) facilitates this effect. In this study, we have first shown a cultural difference in that male Chinese subjects actually perform significantly worse in the same reinforcement associated learning task with social (emotional faces) compared with non-social feedback. Nevertheless, in two independent double-blind placebo (PLC) controlled between-subject design experiments we found OXT still selectively facilitated learning with social feedback. Similar to Caucasian subjects this OXT effect was strongest with feedback using female rather than male faces. One experiment performed in conjunction with functional magnetic resonance imaging showed that during the response, but not feedback phase of the task, OXT selectively increased activity in the amygdala, hippocampus, parahippocampal gyrus and putamen during the social feedback condition, and functional connectivity between the amygdala and insula and caudate. Therefore, OXT may be increasing the salience and reward value of anticipated social feedback. In the PLC group, response times and state anxiety scores during social feedback were associated with signal changes in these same regions but not in the OXT group. OXT may therefore have also facilitated learning by reducing anxiety in the social feedback condition. Overall our results provide the first evidence for cultural differences in social facilitation of learning per se, but a similar selective enhancement of learning with social feedback under OXT. This effect of OXT may be associated with enhanced responses and functional connectivity in emotional memory and reward processing regions. © 2015 Wiley Periodicals, Inc.

  11. Influence of controlled encoding and retrieval facilitation on memory performance in patients with different profiles of mild cognitive impairment.

    Science.gov (United States)

    Perri, Roberta; Monaco, Marco; Fadda, Lucia; Serra, Laura; Marra, Camillo; Caltagirone, Carlo; Bruni, Amalia C; Curcio, Sabrina; Bozzali, M; Carlesimo, Giovanni A

    2015-01-01

    Memory tests able to differentiate encoding and retrieval processes from the memoranda storing ones should be used to differentiate patients in a very early phase of AD. In fact, individuals with mild cognitive impairment (MCI) can be characterized by two different memory profiles: a pure amnestic one (with poor learning and retrieval and poor improvement when encoding is assisted and retrieval is facilitated) and a dysexecutive one (with inefficient encoding and/or poor retrieval strategies and improvement with assisted encoding and retrieval). The amnestic profile characterizes subjects affected by medio-temporal atrophy typical of AD. In this study, a Grober-Buschke memory procedure was used to evaluate normal controls and MCI patients with different cognitive profiles: pure amnestic (aMCIsd), amnestic plus other cognitive impairments (aMCImd) and non-amnestic (naMCI). An index of sensitivity of cueing (ISC) measured the advantage passing from free to cued recall. Results showed that both strategic and consolidation abilities were impaired in the aMCIsd and aMCImd groups and were preserved in the naMCI group. aMCImd, however, compensated the memory deficit with assisted encoding and retrieval, but aMCIsd performed very poorly. When MCI subjects were defined according to the ISC value, subjects with poor ISC were primarily in the aMCIsd group and, to a lesser extent, in the aMCImd group and the naMCI group. Finally, patients with a poor ISC showed cerebral atrophy documented in the precocious phase of AD and the retrosplenial cerebral areas seemed to be the most useful areas for identifying patients in the early phase of AD.

  12. Metabolic learning and memory formation by the brain influence systemic metabolic homeostasis.

    Science.gov (United States)

    Zhang, Yumin; Liu, Gang; Yan, Jingqi; Zhang, Yalin; Li, Bo; Cai, Dongsheng

    2015-04-07

    Metabolic homeostasis is regulated by the brain, but whether this regulation involves learning and memory of metabolic information remains unexplored. Here we use a calorie-based, taste-independent learning/memory paradigm to show that Drosophila form metabolic memories that help in balancing food choice with caloric intake; however, this metabolic learning or memory is lost under chronic high-calorie feeding. We show that loss of individual learning/memory-regulating genes causes a metabolic learning defect, leading to elevated trehalose and lipid levels. Importantly, this function of metabolic learning requires not only the mushroom body but also the hypothalamus-like pars intercerebralis, while NF-κB activation in the pars intercerebralis mimics chronic overnutrition in that it causes metabolic learning impairment and disorders. Finally, we evaluate this concept of metabolic learning/memory in mice, suggesting that the hypothalamus is involved in a form of nutritional learning and memory, which is critical for determining resistance or susceptibility to obesity. In conclusion, our data indicate that the brain, and potentially the hypothalamus, direct metabolic learning and the formation of memories, which contribute to the control of systemic metabolic homeostasis.

  13. Metabolic learning and memory formation by the brain influence systemic metabolic homeostasis

    Science.gov (United States)

    Zhang, Yumin; Liu, Gang; Yan, Jingqi; Zhang, Yalin; Li, Bo; Cai, Dongsheng

    2015-01-01

    Metabolic homeostasis is regulated by the brain, whether this regulation involves learning and memory of metabolic information remains unexplored. Here we use a calorie-based, taste-independent learning/memory paradigm to show that Drosophila form metabolic memories that help balancing food choice with caloric intake; however, this metabolic learning or memory is lost under chronic high-calorie feeding. We show that loss of individual learning/memory-regulating genes causes a metabolic learning defect, leading to elevated trehalose and lipids levels. Importantly, this function of metabolic learning requires not only the mushroom body but the hypothalamus-like pars intercerebralis, while NF-κB activation in the pars intercerebralis mimics chronic overnutrition in that it causes metabolic learning impairment and disorders. Finally, we evaluate this concept of metabolic learning/memory in mice, suggesting the hypothalamus is involved in a form of nutritional learning and memory, which is critical for determining resistance or susceptibility to obesity. In conclusion, our data indicate the brain, and potentially the hypothalamus, direct metabolic learning and the formation of memories, which contribute to the control of systemic metabolic homeostasis. PMID:25848677

  14. Hippocampal long-term depression is facilitated by the acquisition and updating of memory of spatial auditory content and requires mGlu5 activation.

    Science.gov (United States)

    Dietz, Birte; Manahan-Vaughan, Denise

    2017-03-15

    Long-term potentiation (LTP) and long-term depression (LTD) are key cellular processes that support memory formation. Whereas increases of synaptic strength by means of LTP may support the creation of a spatial memory 'engram', LTD appears to play an important role in refining and optimising experience-dependent encoding. A differentiation in the role of hippocampal subfields is apparent. For example, LTD in the dentate gyrus (DG) is enabled by novel learning about large visuospatial features, whereas in area CA1, it is enabled by learning about discrete aspects of spatial content, whereby, both discrete visuospatial and olfactospatial cues trigger LTD in CA1. Here, we explored to what extent local audiospatial cues facilitate information encoding in the form of LTD in these subfields. Coupling of low frequency afferent stimulation (LFS) with discretely localised, novel auditory tones in the sonic hearing, or ultrasonic range, facilitated short-term depression (STD) into LTD (>24 h) in CA1, but not DG. Re-exposure to the now familiar audiospatial configuration ca. 1 week later failed to enhance STD. Reconfiguration of the same audiospatial cues resulted anew in LTD when ultrasound, but not non-ultrasound cues were used. LTD facilitation that was triggered by novel exposure to spatially arranged tones, or to spatial reconfiguration of the same tones were both prevented by an antagonism of the metabotropic glutamate receptor, mGlu5. These data indicate that, if behaviourally salient enough, the hippocampus can use audiospatial cues to facilitate LTD that contributes to the encoding and updating of spatial representations. Effects are subfield-specific, and require mGlu5 activation, as is the case for visuospatial information processing. These data reinforce the likelihood that LTD supports the encoding of spatial features, and that this occurs in a qualitative and subfield-specific manner. They also support that mGlu5 is essential for synaptic encoding of spatial

  15. Formation of model-free motor memories during motor adaptation depends on perturbation schedule.

    Science.gov (United States)

    Orban de Xivry, Jean-Jacques; Lefèvre, Philippe

    2015-04-01

    Motor adaptation to an external perturbation relies on several mechanisms such as model-based, model-free, strategic, or repetition-dependent learning. Depending on the experimental conditions, each of these mechanisms has more or less weight in the final adaptation state. Here we focused on the conditions that lead to the formation of a model-free motor memory (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011), i.e., a memory that does not depend on an internal model or on the size or direction of the errors experienced during the learning. The formation of such model-free motor memory was hypothesized to depend on the schedule of the perturbation (Orban de Xivry JJ, Ahmadi-Pajouh MA, Harran MD, Salimpour Y, Shadmehr R. J Neurophysiol 109: 124-136, 2013). Here we built on this observation by directly testing the nature of the motor memory after abrupt or gradual introduction of a visuomotor rotation, in an experimental paradigm where the presence of model-free motor memory can be identified (Huang VS, Haith AM, Mazzoni P, Krakauer JW. Neuron 70: 787-801, 2011). We found that relearning was faster after abrupt than gradual perturbation, which suggests that model-free learning is reduced during gradual adaptation to a visuomotor rotation. In addition, the presence of savings after abrupt introduction of the perturbation but gradual extinction of the motor memory suggests that unexpected errors are necessary to induce a model-free motor memory. Overall, these data support the hypothesis that different perturbation schedules do not lead to a more or less stabilized motor memory but to distinct motor memories with different attributes and neural representations. Copyright © 2015 the American Physiological Society.

  16. Memory formation in reversal learning of the honeybee

    Directory of Open Access Journals (Sweden)

    Ravit Hadar

    2010-12-01

    Full Text Available In reversal learning animals are first trained with a differential learning protocol, where they learn to respond to a reinforced odor (CS+ and not to respond to a nonreinforced odor (CS-. Once they respond correctly to this rule, the contingencies of the conditioned stimuli are reversed, and animals learn to adjust their response to the new rule. This study investigated the effect of a protein synthesis inhibitor (emetine on the memory formed after reversal learning in the honeybee Apis mellifera. Two groups of bees were studied: summer bees and winter bees, each yielded different results. Blocking protein synthesis in summer bees inhibits consolidation of the excitatory learning following reversal learning whereas it blocked the consolidation of the inhibitory learning in winter bees. These findings suggest that excitatory and inhibitory learning may involve different molecular processes in bees, which are seasonally dependent.

  17. Septo-Hippocampo-Septal Loop and Memory Formation

    Directory of Open Access Journals (Sweden)

    Fatemeh Khakpai

    2013-01-01

    Full Text Available   Cholinergic and GABAergic fibers in the medial septal/diagonal band of Broca (MS/DB area project to the hippocampus and constitute the septo-hippocampal pathway, which has been proven in learning and memory. In addition, the hippocampus has bidirectional connections with the septum, which use this relation for self-regulation of cholinergic input.   The activity of septal and hippocampal neurons is modulated by several neurotransmitters including glutamatergic neurons from the entorhinal cortex, serotonergic fibers from the raphe nucleus, dopaminergic neurons from the ventral tegmental area (VTA, histaminergic cells from the tuberomammillary nucleus and adrenergic fibers from the locus coeruleus (LC. Thus, changes in the glutamatergic, serotonergic and etc. mediated transmission in the MS/DB may influence cholinergic or GABAergic transmission in the hippocampus.

  18. Septo-Hippocampo-Septal Loop and Memory Formation

    Directory of Open Access Journals (Sweden)

    Fatemeh Khakpai

    2013-02-01

    Full Text Available The Cholinergic and GABAergic .bers of the medial septal/diagonal band of Broca (MS/DB area project to the hippocampus and constitute the septo-hippocampal pathway, which has been proven to play a role in learning and memory. In addition, the hippocampus has bidirectional connections with the septum so that to self-regulate of cholinergic input. The activity of septal and hippocampal neurons is modulated by several neurotransmitter systems including glutamatergic neurons from the entorhinal cortex, serotonergic .bers from the raphe nucleus, dopaminergic neurons from the ventral tegmental area (VTA, histaminergic cells from the tuberomammillary nucleus and adrenergic .bers from the locus coeruleus (LC. Thus, changes in the glutamatergic, serotonergic and other systems- mediated transmission in the MS/DB may in.uence cholinergic or GABAergic transmission in the hippocampus.

  19. Opposing roles for GABAA and GABAC receptors in short-term memory formation in young chicks.

    Science.gov (United States)

    Gibbs, M E; Johnston, G A R

    2005-01-01

    The inhibitory neurotransmitter GABA has both inhibitory and enhancing effects on short-term memory for a bead discrimination task in the young chick. Low doses of GABA (1-3 pmol/hemisphere) injected into the multimodal association area of the chick forebrain, inhibit strongly reinforced memory, whereas higher doses (30-100 pmol/hemisphere) enhance weakly reinforced memory. The effect of both high and low doses of GABA is clearly on short-term memory in terms of both the time of injection and in the time that the memory loss occurs. We argue on the basis of relative sensitivities to GABA and to selective GABA receptor antagonists that low doses of GABA act at GABAC receptors (EC50 approximately 1 microM) and the higher doses of GABA act via GABAA receptors (EC50 approximately 10 microM). The selective GABAA receptor antagonist bicuculline inhibited strongly reinforced memory in a dose and time dependent manner, whereas the selective GABAC receptor antagonists TPMPA and P4MPA enhanced weakly reinforced in a dose and time dependent manner. Confirmation that different levels of GABA affect different receptor subtypes was demonstrated by the shift in the GABA dose-response curves to the selective antagonists. It is clear that GABA is involved in the control of short-term memory formation and its action, enhancing or inhibiting, depends on the level of GABA released at the time of learning.

  20. Lactate release from astrocytes to neurons contributes to cocaine memory formation

    KAUST Repository

    Boury-Jamot, Benjamin; Halfon, Olivier; Magistretti, Pierre J.; Boutrel, Benjamin

    2016-01-01

    The identification of neural substrates underlying the long lasting debilitating impact of drug cues is critical for developing novel therapeutic tools. Metabolic coupling has long been considered a key mechanism through which astrocytes and neurons actively interact in response of neuronal activity, but recent findings suggested that disrupting metabolic coupling may represent an innovative approach to prevent memory formation, in particular drug-related memories. Here, we review converging evidence illustrating how memory and addiction share neural circuitry and molecular mechanisms implicating lactate-mediated metabolic coupling between astrocytes and neurons. With several aspects of addiction depending on mnemonic processes elicited by drug experience, disrupting lactate transport involved in the formation of a pathological learning, linking the incentive, and motivational effects of drugs with drug-conditioned stimuli represent a promising approach to encourage abstinence.

  1. Inferential Costs of Trait Centrality in Impression Formation: Organization in Memory and Misremembering

    Directory of Open Access Journals (Sweden)

    Ludmila D. Nunes

    2017-08-01

    Full Text Available An extension of the DRM paradigm was used to study the impact of central traits (Asch, 1946 in impression formation. Traits corresponding to the four clusters of the implicit theory of personality—intellectual, positive and negative; and social, positive and negative (Rosenberg et al., 1968—were used to develop lists containing several traits of one cluster and one central trait prototypical of the opposite cluster. Participants engaging in impression formation relative to participants engaging in memorization not only produced higher levels of false memories corresponding to the same cluster of the list traits but, under response time pressure at retrieval, also produced more false memories of the cluster corresponding to the central trait. We argue that the importance of central traits stems from their ability to activate their corresponding semantic space within a specialized associative memory structure underlying the implicit theory of personality.

  2. Inferential Costs of Trait Centrality in Impression Formation: Organization in Memory and Misremembering

    Science.gov (United States)

    Nunes, Ludmila D.; Garcia-Marques, Leonel; Ferreira, Mário B.; Ramos, Tânia

    2017-01-01

    An extension of the DRM paradigm was used to study the impact of central traits (Asch, 1946) in impression formation. Traits corresponding to the four clusters of the implicit theory of personality—intellectual, positive and negative; and social, positive and negative (Rosenberg et al., 1968)—were used to develop lists containing several traits of one cluster and one central trait prototypical of the opposite cluster. Participants engaging in impression formation relative to participants engaging in memorization not only produced higher levels of false memories corresponding to the same cluster of the list traits but, under response time pressure at retrieval, also produced more false memories of the cluster corresponding to the central trait. We argue that the importance of central traits stems from their ability to activate their corresponding semantic space within a specialized associative memory structure underlying the implicit theory of personality. PMID:28878708

  3. Pituitary adenylate cyclase activating polypeptide plays a role in olfactory memory formation in chicken.

    Science.gov (United States)

    Józsa, Rita; Hollósy, Tibor; Tamás, Andrea; Tóth, Gábor; Lengvári, István; Reglodi, Dóra

    2005-11-01

    PACAP plays an important role during development of the nervous system and is also involved in memory processing. The aim of the present study was to investigate the function of PACAP in chicken embryonic olfactory memory formation by blocking PACAP at a sensitive period in ovo. Chicken were exposed daily to strawberry scent in ovo from embryonic day 15. Control eggs were treated only with saline, while other eggs received a single injection of the PACAP antagonist PACAP6-38 at day 15. The consumption of scented and unscented water was measured daily after hatching. Animals exposed to strawberry scent in ovo showed no preference. However, chickens exposed to PACAP6-38, showed a clear preference for plain water, similarly to unexposed chicken. Our present study points to PACAP's possible importance in embryonic olfactory memory formation.

  4. Lactate release from astrocytes to neurons contributes to cocaine memory formation

    KAUST Repository

    Boury-Jamot, Benjamin

    2016-10-12

    The identification of neural substrates underlying the long lasting debilitating impact of drug cues is critical for developing novel therapeutic tools. Metabolic coupling has long been considered a key mechanism through which astrocytes and neurons actively interact in response of neuronal activity, but recent findings suggested that disrupting metabolic coupling may represent an innovative approach to prevent memory formation, in particular drug-related memories. Here, we review converging evidence illustrating how memory and addiction share neural circuitry and molecular mechanisms implicating lactate-mediated metabolic coupling between astrocytes and neurons. With several aspects of addiction depending on mnemonic processes elicited by drug experience, disrupting lactate transport involved in the formation of a pathological learning, linking the incentive, and motivational effects of drugs with drug-conditioned stimuli represent a promising approach to encourage abstinence.

  5. Activation of midbrain structures by associative novelty and the formation of explicit memory in humans.

    Science.gov (United States)

    Schott, Björn H; Sellner, Daniela B; Lauer, Corinna-J; Habib, Reza; Frey, Julietta U; Guderian, Sebastian; Heinze, Hans-Jochen; Düzel, Emrah

    2004-01-01

    Recent evidence suggests a close functional relationship between memory formation in the hippocampus and dopaminergic neuromodulation originating in the ventral tegmental area and medial substantia nigra of the midbrain. Here we report midbrain activation in two functional MRI studies of visual memory in healthy young adults. In the first study, participants distinguished between familiar and novel configurations of pairs of items which had been studied together by either learning the location or the identity of the items. In the second study, participants studied words by either rating the words' pleasantness or counting syllables. The ventral tegmental area and medial substantia nigra showed increased activation by associative novelty (first study) and subsequent free recall performance (second study). In both studies, this activation accompanied hippocampal activation, but was unaffected by the study task. Thus midbrain regions seem to participate selectively in hippocampus-dependent processes of associative novelty and explicit memory formation, but appear to be unaffected by other task-relevant aspects.

  6. HDAC3 Is a Critical Negative Regulator of Long-Term Memory Formation

    Science.gov (United States)

    McQuown, Susan C.; Barrett, Ruth M.; Matheos, Dina P.; Post, Rebecca J.; Rogge, George A.; Alenghat, Theresa; Mullican, Shannon E.; Jones, Steven; Rusche, James R.; Lazar, Mitchell A.; Wood, Marcelo A.

    2011-01-01

    Gene expression is dynamically regulated by chromatin modifications on histone tails, such as acetylation. In general, histone acetylation promotes transcription, whereas histone deacetylation negatively regulates transcription. The interplay between histone acetyl-transerases and histone deacetylases (HDACs) is pivotal for the regulation of gene expression required for long-term memory processes. Currently, very little is known about the role of individual HDACs in learning and memory. We examined the role of HDAC3 in long-term memory using a combined genetic and pharmacologic approach. We used HDAC3–FLOX genetically modified mice in combination with adeno-associated virus-expressing Cre recombinase to generate focal homozygous deletions of Hdac3 in area CA1 of the dorsal hippocampus. To complement this approach, we also used a selective inhibitor of HDAC3, RGFP136 [N-(6-(2-amino-4-fluorophenylamino)-6-oxohexyl)-4-methylbenzamide]. Immunohistochemistry showed that focal deletion or intrahippocampal delivery of RGFP136 resulted in increased histone acetylation. Both the focal deletion of HDAC3 as well as HDAC3 inhibition via RGFP136 significantly enhanced long-term memory in a persistent manner. Next we examined expression of genes implicated in long-term memory from dorsal hippocampal punches using quantitative reverse transcription-PCR. Expression of nuclear receptor subfamily 4 group A, member 2 (Nr4a2) and c-fos was significantly increased in the hippocampus of HDAC3–FLOX mice compared with wild-type controls. Memory enhancements observed in HDAC3–FLOX mice were abolished by intrahippocampal delivery of Nr4a2 small interfering RNA, suggesting a mechanism by which HDAC3 negatively regulates memory formation. Together, these findings demonstrate a critical role for HDAC3 in the molecular mechanisms underlying long-term memory formation. PMID:21228185

  7. Cognitive Association Formation in Episodic Memory: Evidence from Event-Related Potentials

    Science.gov (United States)

    Kim, Alice S. N.; Vallesi, Antonino; Picton, Terence W.; Tulving, Endel

    2009-01-01

    The present study focused on the processes underlying cognitive association formation by investigating subsequent memory effects. Event-related potentials were recorded as participants studied pairs of words, presented one word at a time, for later recall. The findings showed that a frontal-positive late wave (LW), which occurred 1-1.6 s after the…

  8. CREB binding protein is required for both short-term and long-term memory formation.

    NARCIS (Netherlands)

    Chen, G.; Zou, X.; Watanabe, H.; Deursen, J.M.A. van; Shen, J.

    2010-01-01

    CREB binding protein (CBP) is a transcriptional coactivator with histone acetyltransferase activity. Our prior study suggested that CBP might be a key target of presenilins in the regulation of memory formation and neuronal survival. To elucidate the role of CBP in the adult brain, we generated

  9. Intuitive Action Set Formation in Learning Classifier Systems with Memory Registers

    NARCIS (Netherlands)

    Simões, L.F.; Schut, M.C.; Haasdijk, E.W.

    2008-01-01

    An important design goal in Learning Classifier Systems (LCS) is to equally reinforce those classifiers which cause the level of reward supplied by the environment. In this paper, we propose a new method for action set formation in LCS. When applied to a Zeroth Level Classifier System with Memory

  10. Declarative memory formation in hippocampal sclerosis: an intracranial event-related potentials study.

    NARCIS (Netherlands)

    Mormann, F.; Fernandez, G.S.E.; Klaver, P.; Weber, B.; Elger, C.E.; Fell, J.

    2007-01-01

    The functional deficits associated with hippocampal sclerosis during declarative memory formation are largely unknown. In this study, we analyzed intracranial event-related potentials recorded from the medial temporal lobes of nine epilepsy patients performing a word memorization task. We used

  11. Gene repressive mechanisms in the mouse brain involved in memory formation.

    Science.gov (United States)

    Yu, Nam-Kyung; Kaang, Bong-Kiun

    2016-04-01

    Gene regulation in the brain is essential for long-term plasticity and memory formation. Despite this established notion, the quantitative translational map in the brain during memory formation has not been reported. To systematically probe the changes in protein synthesis during memory formation, our recent study exploited ribosome profiling using the mouse hippocampal tissues at multiple time points after a learning event. Analysis of the resulting database revealed novel types of gene regulation after learning. First, the translation of a group of genes was rapidly suppressed without change in mRNA levels. At later time points, the expression of another group of genes was downregulated through reduction in mRNA levels. This reduction was predicted to be downstream of inhibition of ESR1 (Estrogen Receptor 1) signaling. Overexpressing Nrsn1, one of the genes whose translation was suppressed, or activating ESR1 by injecting an agonist interfered with memory formation, suggesting the functional importance of these findings. Moreover, the translation of genes encoding the translational machineries was found to be suppressed, among other genes in the mouse hippocampus. Together, this unbiased approach has revealed previously unidentified characteristics of gene regulation in the brain and highlighted the importance of repressive controls. [BMB Reports 2016; 49(4): 199-200].

  12. Intermediate levels of hippocampal activity appear optimal for associative memory formation.

    NARCIS (Netherlands)

    Liu, X.; Qin, S.; Rijpkema, M.J.P.; Luo, J.; Fernandez, G.S.E.

    2010-01-01

    BACKGROUND: It is well established that hippocampal activity is positively related to effective associative memory formation. However, in biological systems often optimal levels of activity are contrasted by both sub- and supra-optimal levels. Sub-optimal levels of hippocampal activity are commonly

  13. Formation and adaptation of memory : Neurobiological mechanisms underlying learning and reversal learning

    NARCIS (Netherlands)

    Havekes, Robbert

    2008-01-01

    The hippocampus is a brain region that plays a critical role in memory formation. In addition, it has been suggested that this brain region is important for ‘updating’ information that is incorrect or outdated. The main goal of this thesis project was to investigate which neurobiological processes

  14. Tianeptine: 5-HT uptake sites and 5-HT(1-7) receptors modulate memory formation in an autoshaping Pavlovian/instrumental task.

    Science.gov (United States)

    Meneses, Alfredo

    2002-05-01

    Recent studies using invertebrate and mammal species have revealed that, endogenous serotonin (5-hydroxytryptamine, 5-HT) modulates cognitive processes, particularly learning and memory, though, at present, it is unclear the manner, where, and how long 5-HT systems are involved. Hence in this work, an attempt was made to study the effects of 5-HT endogenous on memory formation, using a 5-HT uptake facilitator (tianeptine) and, selective 5-HT(1-7) receptor antagonists to determine whether 5-HT uptake sites and which 5-HT receptors are involved, respectively. Results showed that post-training tianeptine injection enhanced memory consolidation in an autoshaping Pavlovian/instrumental learning task, which has been useful to detect changes on memory formation elicited by drugs or aging. On interaction experiments, ketanserin (5-HT(1D/2A/2C) antagonist) slightly enhanced tianeptine effects, while WAY 100635 (5-HT(1A) antagonist), SB-224289 (5-HT(1B) inverse agonist), SB-200646 (5-HT(2B/2C) antagonist), ondansetron (5-HT(3) antagonist), GR 127487 (5-HT(4) antagonist), Ro 04-6790 (5-HT(6) antagonist), DR 4004 (5-HT(7) antagonist), or fluoxetine (an inhibitor of 5-HT reuptake) blocked the facilitatory tianeptine effect. Notably, together tianeptine and Ro 04-6790 impaired learning consolidation. Moreover, 5-HT depletion completely reversed the tianeptine effect. Tianeptine also normalized an impaired memory elicited by scopolamine (an antimuscarinic) or dizocilpine (non-competitive glutamatergic antagonist), while partially reversed that induced by TFMPP (5-HT(1B/1D/2A-2C/7) agonist/antagonist). Finally, tianeptine-fluoxetine coadministration had no effect on learning consolidation; nevertheless, administration of an acetylcholinesterase inhibitor, phenserine, potentiated subeffective tianeptine or fluoxetine doses. Collectively, these data confirmed that endogenously 5-HT modulates, via uptake sites and 5-HT(1-7) receptors, memory consolidation, and are consistent with the

  15. Protein degradation and protein synthesis in long-term memory formation

    Directory of Open Access Journals (Sweden)

    Timothy J Jarome

    2014-06-01

    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.

  16. When Learning Disturbs Memory – Temporal Profile of Retroactive Interference of Learning on Memory Formation

    Science.gov (United States)

    Sosic-Vasic, Zrinka; Hille, Katrin; Kröner, Julia; Spitzer, Manfred; Kornmeier, Jürgen

    2018-01-01

    Introduction: Consolidation is defined as the time necessary for memory stabilization after learning. In the present study we focused on effects of interference during the first 12 consolidation minutes after learning. Participants had to learn a set of German – Japanese word pairs in an initial learning task and a different set of German – Japanese word pairs in a subsequent interference task. The interference task started in different experimental conditions at different time points (0, 3, 6, and 9 min) after the learning task and was followed by subsequent cued recall tests. In a control experiment the interference periods were replaced by rest periods without any interference. Results: The interference task decreased memory performance by up to 20%, with negative effects at all interference time points and large variability between participants concerning both the time point and the size of maximal interference. Further, fast learners seem to be more affected by interference than slow learners. Discussion: Our results indicate that the first 12 min after learning are highly important for memory consolidation, without a general pattern concerning the precise time point of maximal interference across individuals. This finding raises doubts about the generalized learning recipes and calls for individuality of learning schedules. PMID:29503621

  17. When Learning Disturbs Memory – Temporal Profile of Retroactive Interference of Learning on Memory Formation

    Directory of Open Access Journals (Sweden)

    Zrinka Sosic-Vasic

    2018-02-01

    Full Text Available Introduction: Consolidation is defined as the time necessary for memory stabilization after learning. In the present study we focused on effects of interference during the first 12 consolidation minutes after learning. Participants had to learn a set of German – Japanese word pairs in an initial learning task and a different set of German – Japanese word pairs in a subsequent interference task. The interference task started in different experimental conditions at different time points (0, 3, 6, and 9 min after the learning task and was followed by subsequent cued recall tests. In a control experiment the interference periods were replaced by rest periods without any interference.Results: The interference task decreased memory performance by up to 20%, with negative effects at all interference time points and large variability between participants concerning both the time point and the size of maximal interference. Further, fast learners seem to be more affected by interference than slow learners.Discussion: Our results indicate that the first 12 min after learning are highly important for memory consolidation, without a general pattern concerning the precise time point of maximal interference across individuals. This finding raises doubts about the generalized learning recipes and calls for individuality of learning schedules.

  18. Visuospatial working memory training facilitates visually-aided explicit sequence learning.

    Science.gov (United States)

    Chan, John S Y; Wu, Qiaofeng; Liang, Danxia; Yan, Jin H

    2015-10-01

    Finger sequence learning requires visuospatial working memory (WM). However, the dynamics between age, WM training, and motor skill acquisition are unclear. Therefore, we examined how visuospatial WM training improves finger movement sequential accuracy in younger (n=26, 21.1±1.37years) and older adults (n=22, 70.6±4.01years). After performing a finger sequence learning exercise and numerical and spatial WM tasks, participants in each age group were randomly assigned to either the experimental (EX) or control (CO) groups. For one hour daily over a 10-day period, the EX group practiced an adaptive n-back spatial task while those in the CO group practiced a non-adaptive version. As a result of WM practice, the EX participants increased their accuracy in the spatial n-back tasks, while accuracy remained unimproved in the numerical n-back tasks. In all groups, reaction times (RT) became shorter in most numerical and spatial n-back tasks. The learners in the EX group - but not in the CO group - showed improvements in their retention of finger sequences. The findings support our hypothesis that computerized visuospatial WM training improves finger sequence learning both in younger and in older adults. We discuss the theoretical implications and clinical relevance of this research for motor learning and functional rehabilitation. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.

    Science.gov (United States)

    Kittelberger, Kara A; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G

    2012-01-01

    Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.

  20. Natural Amyloid-Beta Oligomers Acutely Impair the Formation of a Contextual Fear Memory in Mice

    Science.gov (United States)

    Kittelberger, Kara A.; Piazza, Fabrizio; Tesco, Giuseppina; Reijmers, Leon G.

    2012-01-01

    Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD). It has been proposed that soluble amyloid-beta (Abeta) oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss. PMID:22238679

  1. Natural amyloid-β oligomers acutely impair the formation of a contextual fear memory in mice.

    Directory of Open Access Journals (Sweden)

    Kara A Kittelberger

    Full Text Available Memory loss is one of the hallmark symptoms of Alzheimer's disease (AD. It has been proposed that soluble amyloid-beta (Abeta oligomers acutely impair neuronal function and thereby memory. We here report that natural Abeta oligomers acutely impair contextual fear memory in mice. A natural Abeta oligomer solution containing Abeta monomers, dimers, trimers, and tetramers was derived from the conditioned medium of 7PA2 cells, a cell line that expresses human amyloid precursor protein containing the Val717Phe familial AD mutation. As a control we used 7PA2 conditioned medium from which Abeta oligomers were removed through immunodepletion. Separate groups of mice were injected with Abeta and control solutions through a cannula into the lateral brain ventricle, and subjected to fear conditioning using two tone-shock pairings. One day after fear conditioning, mice were tested for contextual fear memory and tone fear memory in separate retrieval trials. Three experiments were performed. For experiment 1, mice were injected three times: 1 hour before and 3 hours after fear conditioning, and 1 hour before context retrieval. For experiments 2 and 3, mice were injected a single time at 1 hour and 2 hours before fear conditioning respectively. In all three experiments there was no effect on tone fear memory. Injection of Abeta 1 hour before fear conditioning, but not 2 hours before fear conditioning, impaired the formation of a contextual fear memory. In future studies, the acute effect of natural Abeta oligomers on contextual fear memory can be used to identify potential mechanisms and treatments of AD associated memory loss.

  2. Corticosterone facilitates extinction of fear memory in BALB/c mice but strengthens cue related fear in C57BL/6 mice.

    Science.gov (United States)

    Brinks, V; de Kloet, E R; Oitzl, M S

    2009-04-01

    Corticosterone, the naturally occurring glucocorticoid of rodents is secreted in response to stressors and is known for its facilitating and detrimental effects on emotional learning and memory. The large variability in the action of corticosterone on processing of emotional memories is postulated to depend on genetic background and the spatio-temporal domain in which the hormone operates. To address this hypothesis, mice of two strains with distinct corticosterone secretory patterns and behavioural phenotype (BALB/c and C57BL/6J) were treated with corticosterone (250 microg/kg, i.p.), either 5 min before or directly after acquisition in a fear conditioning task. As the paradigm allowed assessing in one experimental procedure both context- and cue-related fear behaviour, we were able to detect generalization and specificity of fear. BALB/c showed generalized strong fear memory, while C57BL/6J mice discriminated between freezing during context- and cue episodes. Corticosterone had opposite effects on fear memory depending on the strain and time of injection. Corticosterone after acquisition did not affect C57BL/6J mice, but destabilized consolidation and facilitated extinction in BALB/c. Corticosterone 5 min before acquisition strengthened stress-associated signals: BALB/c no longer showed lower fear memory, while C57BL/6J mice displayed increased fear memory and impaired extinction in cue episodes. We propose that corticosterone-induced facilitation of fear memory in C57BL/6J mice can be used to study the development of fear memories, corticosterone administration in BALB/c mice presents a model to examine treatment. We conclude that genetic background and time of corticosterone action are modifiers of fear memory with interesting translational implications for anxiety-related diseases.

  3. Neuroticism and conscientiousness respectively constrain and facilitate short-term plasticity within the working memory neural network.

    Science.gov (United States)

    Dima, Danai; Friston, Karl J; Stephan, Klaas E; Frangou, Sophia

    2015-10-01

    Individual differences in cognitive efficiency, particularly in relation to working memory (WM), have been associated both with personality dimensions that reflect enduring regularities in brain configuration, and with short-term neural plasticity, that reflects task-related changes in brain connectivity. To elucidate the relationship of these two divergent mechanisms, we tested the hypothesis that personality dimensions, which reflect enduring aspects of brain configuration, inform about the neurobiological framework within which short-term, task-related plasticity, as measured by effective connectivity, can be facilitated or constrained. As WM consistently engages the dorsolateral prefrontal (DLPFC), parietal (PAR), and anterior cingulate cortex (ACC), we specified a WM network model with bidirectional, ipsilateral, and contralateral connections between these regions from a functional magnetic resonance imaging dataset obtained from 40 healthy adults while performing the 3-back WM task. Task-related effective connectivity changes within this network were estimated using Dynamic Causal Modelling. Personality was evaluated along the major dimensions of Neuroticism, Extraversion, Openness to Experience, Agreeableness, and Conscientiousness. Only two dimensions were relevant to task-dependent effective connectivity. Neuroticism and Conscientiousness respectively constrained and facilitated neuroplastic responses within the WM network. These results suggest individual differences in cognitive efficiency arise from the interplay between enduring and short-term plasticity in brain configuration. © 2015 Wiley Periodicals, Inc.

  4. Self-regulation of frontal-midline theta facilitates memory updating and mental set shifting

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    Stefanie eEnriquez-Geppert

    2014-12-01

    Full Text Available Frontal-midline (fm theta oscillations as measured via the electroencephalogram (EEG have been suggested as neural working language of executive functioning. Their power has been shown to increase when cognitive processing or task performance is enhanced. Thus, the question arises whether learning to increase fm-theta amplitudes would functionally impact the behavioral performance in tasks probing executive functions (EFs. Here, the effects of neurofeedback, a learning method to self-up-regulate fm-theta over frontal-midline electrodes, on the four most representative EFs, memory updating, set shifting, conflict monitoring, and motor inhibition are presented. Before beginning and after completing an individualized, eight-session gap-spaced neurofeedback intervention, the three-back, letter/number task-switching, Stroop, and stop-signal tasks were tested while measuring the EEG. Self-determined up-regulation of fm-theta and its putative role for executive functioning were compared to an active control group, the so-called pseudo-neurofeedback group. Task-related fm-theta activity after training differed significantly between groups. More importantly, though, after neurofeedback significantly enhanced behavioral performance was observed. The training group showed higher accuracy scores in the three-back task and reduced mixing and shifting costs in letter/number task-switching. However, this specific protocol type did not affect performance in tasks probing conflict monitoring and motor inhibition. Thus, our results suggest a modulation of proactive but not reactive mechanisms of cognitive control. In sum, the modulation of fm-theta via neurofeedback may serve as potent treatment approach for executive dysfunctions.

  5. NO is required for memory formation and expression of memory, and for minor behavioral changes during training with inedible food in Aplysia.

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    Briskin-Luchinsky, Valeria; Tam, Shlomit; Shabbat, Shlomit; Hurwitz, Itay; Susswein, Abraham J

    2018-05-01

    A learning experience may lead to changes in behavior during the experience, and also to memory expressed at a later time. Are signals causing changes in behavior during the learning experience related to the formation and expression of memory? We examined this question, using learning that food is inedible in Aplysia Treatment of an isolated buccal ganglia preparation with an NO donor elicited rejection-like motor programs. Rejection initiated by NO production is consistent with aspects of behavioral changes seen while animals learn, and with memory formation. Nonetheless, applying the NO donor during training had only minor effects on behavior during the training, and did not improve memory, indicating that the induction of rejection in the buccal ganglia is unlikely to be the means by which NO during training contributes to memory formation. Block of NO during memory retrieval prevented the expression of memory, as measured by a lack of savings in time to stop responding to food. Applying an NO donor to the cerebral ganglion while eliciting fictive feeding inhibited the expression of feeding activity, indicating that some NO effects on memory consolidation and on expression of memory may be via effects on the cerebral ganglion. © 2018 Briskin-Luchinsky et al.; Published by Cold Spring Harbor Laboratory Press.

  6. Successful declarative memory formation is associated with ongoing activity during encoding in a distributed neocortical network related to working memory: a magnetoencephalography study.

    NARCIS (Netherlands)

    Takashima, A.; Jensen, O.; Oostenveld, R.; Maris, E.G.G.; Coevering, M. van de; Fernandez, G.S.E.

    2006-01-01

    The aim of the present study was to investigate the spatio-temporal characteristics of the neural correlates of declarative memory formation as assessed by the subsequent memory effect, i.e. the difference in encoding activity between subsequently remembered and subsequently forgotten items.

  7. Successful declarative memory formation is associated with ongoing activity during encoding in a distributed neocortical network related to working memory: A magnetoencephalography study

    NARCIS (Netherlands)

    Takashima, A.; Jensen, O.; Oostenveld, R.; Maris, E.G.G.; Coevering, M. van de; Fernandez, G.S.E.

    2006-01-01

    The aim of the present study was to investigate the spatio-temporal characteristics of the neural correlates of declarative memory formation as assessed by the subsequent memory effect, i.e. the difference in encoding activity between subsequently remembered and subsequently forgotten items.

  8. The facilitative effects of glucose ingestion on memory retrieval in younger and older adults: is task difficulty or task domain critical?

    Science.gov (United States)

    Riby, Leigh M; McMurtrie, Hazel; Smallwood, Jonathan; Ballantyne, Carrie; Meikle, Andrew; Smith, Emily

    2006-02-01

    The ingestion of a glucose-containing drink has been shown to improve cognitive performance, particularly memory functioning. However, it remains unclear as to the extent to which task domain and task difficulty moderate the glucose enhancement effect. The aim of this research was to determine whether boosts in performance are restricted to particular classes of memory (episodic v. semantic) or to tasks of considerable cognitive load. A repeated measures (25 g glucose v. saccharin), counterbalanced, double-blind design was used with younger and older adults. Participants performed a battery of episodic (e.g. paired associate learning) and semantic memory (e.g. category verification) tasks under low and high cognitive load. Electrophysiological measures (heart rate and galvanic skin response) of arousal and mental effort were also gathered. The results indicated that whilst glucose appeared to aid episodic remembering, cognitive load did not exaggerate the facilitative effect. For semantic memory, there was little evidence to suggest that glucose can boost semantic memory retrieval even when the load was manipulated. One exception was that glucose facilitated performance during the difficult category fluency task. Regardless, the present findings are consistent with the domain-specific account in which glucose acts primarily on the hippocampal region, which is known to support episodic memory. The possible contribution of the hippocampus in semantic memory processing is also discussed.

  9. Sensory Cortical Plasticity Participates in the Epigenetic Regulation of Robust Memory Formation

    Science.gov (United States)

    Phan, Mimi L.; Bieszczad, Kasia M.

    2016-01-01

    Neuroplasticity remodels sensory cortex across the lifespan. A function of adult sensory cortical plasticity may be capturing available information during perception for memory formation. The degree of experience-dependent remodeling in sensory cortex appears to determine memory strength and specificity for important sensory signals. A key open question is how plasticity is engaged to induce different degrees of sensory cortical remodeling. Neural plasticity for long-term memory requires the expression of genes underlying stable changes in neuronal function, structure, connectivity, and, ultimately, behavior. Lasting changes in transcriptional activity may depend on epigenetic mechanisms; some of the best studied in behavioral neuroscience are DNA methylation and histone acetylation and deacetylation, which, respectively, promote and repress gene expression. One purpose of this review is to propose epigenetic regulation of sensory cortical remodeling as a mechanism enabling the transformation of significant information from experiences into content-rich memories of those experiences. Recent evidence suggests how epigenetic mechanisms regulate highly specific reorganization of sensory cortical representations that establish a widespread network for memory. Thus, epigenetic mechanisms could initiate events to establish exceptionally persistent and robust memories at a systems-wide level by engaging sensory cortical plasticity for gating what and how much information becomes encoded. PMID:26881129

  10. Sensory Cortical Plasticity Participates in the Epigenetic Regulation of Robust Memory Formation.

    Science.gov (United States)

    Phan, Mimi L; Bieszczad, Kasia M

    2016-01-01

    Neuroplasticity remodels sensory cortex across the lifespan. A function of adult sensory cortical plasticity may be capturing available information during perception for memory formation. The degree of experience-dependent remodeling in sensory cortex appears to determine memory strength and specificity for important sensory signals. A key open question is how plasticity is engaged to induce different degrees of sensory cortical remodeling. Neural plasticity for long-term memory requires the expression of genes underlying stable changes in neuronal function, structure, connectivity, and, ultimately, behavior. Lasting changes in transcriptional activity may depend on epigenetic mechanisms; some of the best studied in behavioral neuroscience are DNA methylation and histone acetylation and deacetylation, which, respectively, promote and repress gene expression. One purpose of this review is to propose epigenetic regulation of sensory cortical remodeling as a mechanism enabling the transformation of significant information from experiences into content-rich memories of those experiences. Recent evidence suggests how epigenetic mechanisms regulate highly specific reorganization of sensory cortical representations that establish a widespread network for memory. Thus, epigenetic mechanisms could initiate events to establish exceptionally persistent and robust memories at a systems-wide level by engaging sensory cortical plasticity for gating what and how much information becomes encoded.

  11. Sensory Cortical Plasticity Participates in the Epigenetic Regulation of Robust Memory Formation

    Directory of Open Access Journals (Sweden)

    Mimi L. Phan

    2016-01-01

    Full Text Available Neuroplasticity remodels sensory cortex across the lifespan. A function of adult sensory cortical plasticity may be capturing available information during perception for memory formation. The degree of experience-dependent remodeling in sensory cortex appears to determine memory strength and specificity for important sensory signals. A key open question is how plasticity is engaged to induce different degrees of sensory cortical remodeling. Neural plasticity for long-term memory requires the expression of genes underlying stable changes in neuronal function, structure, connectivity, and, ultimately, behavior. Lasting changes in transcriptional activity may depend on epigenetic mechanisms; some of the best studied in behavioral neuroscience are DNA methylation and histone acetylation and deacetylation, which, respectively, promote and repress gene expression. One purpose of this review is to propose epigenetic regulation of sensory cortical remodeling as a mechanism enabling the transformation of significant information from experiences into content-rich memories of those experiences. Recent evidence suggests how epigenetic mechanisms regulate highly specific reorganization of sensory cortical representations that establish a widespread network for memory. Thus, epigenetic mechanisms could initiate events to establish exceptionally persistent and robust memories at a systems-wide level by engaging sensory cortical plasticity for gating what and how much information becomes encoded.

  12. Interplay between TETs and microRNAs in the adult brain for memory formation.

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    Kremer, Eloïse A; Gaur, Niharika; Lee, Melissa A; Engmann, Olivia; Bohacek, Johannes; Mansuy, Isabelle M

    2018-01-26

    5-hydroxymethylation (5-hmC) is an epigenetic modification on DNA that results from the conversion of 5-methylcytosine by Ten-Eleven Translocation (TET) proteins. 5-hmC is widely present in the brain and is subjected to dynamic regulation during development and upon neuronal activity. It was recently shown to be involved in memory processes but currently, little is known about how it is controlled in the brain during memory formation. Here, we show that Tet3 is selectively up-regulated by activity in hippocampal neurons in vitro, and after formation of fear memory in the hippocampus. This is accompanied by a decrease in miR-29b expression that, through complementary sequences, regulates the level of Tet3 by preferential binding to its 3'UTR. We newly reveal that SAM68, a nuclear RNA-binding protein known to regulate splicing, acts upstream of miR-29 by modulating its biogenesis. Together, these findings identify novel players in the adult brain necessary for the regulation of 5-hmC during memory formation.

  13. Olfactory memory formation and the influence of reward pathway during appetitive learning by honey bees.

    Science.gov (United States)

    Wright, Geraldine A; Mustard, Julie A; Kottcamp, Sonya M; Smith, Brian H

    2007-11-01

    Animals possess the ability to assess food quality via taste and via changes in state that occur after ingestion. Here, we investigate the extent to which a honey bee's ability to assess food quality affected the formation of association with an odor stimulus and the retention of olfactory memories associated with reward. We used three different conditioning protocols in which the unconditioned stimulus (food) was delivered as sucrose stimulation to the proboscis (mouthparts), the antennae or to both proboscis and antennae. All means of delivery of the unconditioned stimulus produced robust associative conditioning with an odor. However, the memory of a conditioned odor decayed at a significantly greater rate for subjects experiencing antennal-only stimulation after either multiple- or single-trial conditioning. Finally, to test whether the act of feeding on a reward containing sucrose during conditioning affected olfactory memory formation, we conditioned honey bees to associate an odor with antennal stimulation with sucrose followed by feeding on a water droplet. We observed that a honey bee's ability to recall the conditioned odor was not significantly different from that of subjects conditioned with an antennal-only sucrose stimulus. Our results show that stimulation of the sensory receptors on the proboscis and/or ingestion of the sucrose reward during appetitive olfactory conditioning are necessary for long-term memory formation.

  14. Deliberation versus automaticity in decision making: Which presentation format features facilitate automatic decision making?

    Directory of Open Access Journals (Sweden)

    Anke Soellner

    2013-05-01

    Full Text Available The idea of automatic decision making approximating normatively optimal decisions without necessitating much cognitive effort is intriguing. Whereas recent findings support the notion that such fast, automatic processes explain empirical data well, little is known about the conditions under which such processes are selected rather than more deliberate stepwise strategies. We investigate the role of the format of information presentation, focusing explicitly on the ease of information acquisition and its influence on information integration processes. In a probabilistic inference task, the standard matrix employed in prior research was contrasted with a newly created map presentation format and additional variations of both presentation formats. Across three experiments, a robust presentation format effect emerged: Automatic decision making was more prevalent in the matrix (with high information accessibility, whereas sequential decision strategies prevailed when the presentation format demanded more information acquisition effort. Further scrutiny of the effect showed that it is not driven by the presentation format as such, but rather by the extent of information search induced by a format. Thus, if information is accessible with minimal need for information search, information integration is likely to proceed in a perception-like, holistic manner. In turn, a moderate demand for information search decreases the likelihood of behavior consistent with the assumptions of automatic decision making.

  15. Presentation format effects in working memory: the role of attention.

    Science.gov (United States)

    Foos, Paul W; Goolkasian, Paula

    2005-04-01

    Four experiments are reported in which participants attempted to remember three or six concrete nouns, presented as pictures, spoken words, or printed words, while also verifying the accuracy of sentences. Hypotheses meant to explain the higher recall of pictures and spoken words over printed words were tested. Increasing the difficulty and changing the type of processing task from arithmetic to a visual/spatial reasoning task did not influence recall. An examination of long-term modality effects showed that those effects were not sufficient to explain the superior performance with spoken words and pictures. Only when we manipulated the allocation of attention to the items in the storage task by requiring the participants to articulate the items and by presenting the stimulus items under a degraded condition were we able to reduce or remove the effect of presentation format. The findings suggest that the better recall of pictures and spoken words over printed words result from the fact that under normal presentation conditions, printed words receive less processing attention than pictures and spoken words do.

  16. The Cambridge Car Memory Test: a task matched in format to the Cambridge Face Memory Test, with norms, reliability, sex differences, dissociations from face memory, and expertise effects.

    Science.gov (United States)

    Dennett, Hugh W; McKone, Elinor; Tavashmi, Raka; Hall, Ashleigh; Pidcock, Madeleine; Edwards, Mark; Duchaine, Bradley

    2012-06-01

    Many research questions require a within-class object recognition task matched for general cognitive requirements with a face recognition task. If the object task also has high internal reliability, it can improve accuracy and power in group analyses (e.g., mean inversion effects for faces vs. objects), individual-difference studies (e.g., correlations between certain perceptual abilities and face/object recognition), and case studies in neuropsychology (e.g., whether a prosopagnosic shows a face-specific or object-general deficit). Here, we present such a task. Our Cambridge Car Memory Test (CCMT) was matched in format to the established Cambridge Face Memory Test, requiring recognition of exemplars across view and lighting change. We tested 153 young adults (93 female). Results showed high reliability (Cronbach's alpha = .84) and a range of scores suitable both for normal-range individual-difference studies and, potentially, for diagnosis of impairment. The mean for males was much higher than the mean for females. We demonstrate independence between face memory and car memory (dissociation based on sex, plus a modest correlation between the two), including where participants have high relative expertise with cars. We also show that expertise with real car makes and models of the era used in the test significantly predicts CCMT performance. Surprisingly, however, regression analyses imply that there is an effect of sex per se on the CCMT that is not attributable to a stereotypical male advantage in car expertise.

  17. Extracellular DNA facilitates the formation of functional amyloids in Staphylococcus aureus biofilms.

    Science.gov (United States)

    Schwartz, Kelly; Ganesan, Mahesh; Payne, David E; Solomon, Michael J; Boles, Blaise R

    2016-01-01

    Persistent staphylococcal infections often involve surface-associated communities called biofilms. Staphylococcus aureus biofilm development is mediated by the co-ordinated production of the biofilm matrix, which can be composed of polysaccharides, extracellular DNA (eDNA) and proteins including amyloid fibers. The nature of the interactions between matrix components, and how these interactions contribute to the formation of matrix, remain unclear. Here we show that the presence of eDNA in S. aureus biofilms promotes the formation of amyloid fibers. Conditions or mutants that do not generate eDNA result in lack of amyloids during biofilm growth despite the amyloidogeneic subunits, phenol soluble modulin peptides, being produced. In vitro studies revealed that the presence of DNA promotes amyloid formation by PSM peptides. Thus, this work exposes a previously unacknowledged interaction between biofilm matrix components that furthers our understanding of functional amyloid formation and S. aureus biofilm biology. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  18. Behavioral tagging is a general mechanism of long-term memory formation.

    Science.gov (United States)

    Ballarini, Fabricio; Moncada, Diego; Martinez, Maria Cecilia; Alen, Nadia; Viola, Haydée

    2009-08-25

    In daily life, memories are intertwined events. Little is known about the mechanisms involved in their interactions. Using two hippocampus-dependent (spatial object recognition and contextual fear conditioning) and one hippocampus-independent (conditioned taste aversion) learning tasks, we show that in rats subjected to weak training protocols that induce solely short term memory (STM), long term memory (LTM) is promoted and formed only if training sessions took place in contingence with a novel, but not familiar, experience occurring during a critical time window around training. This process requires newly synthesized proteins induced by novelty and reveals a general mechanism of LTM formation that begins with the setting of a "learning tag" established by a weak training. These findings represent the first comprehensive set of evidences indicating the existence of a behavioral tagging process that in analogy to the synaptic tagging and capture process, need the creation of a transient, protein synthesis-independent, and input specific tag.

  19. Differential effects of beta-adrenergic receptor blockade in the medial prefrontal cortex during aversive and incidental taste memory formation.

    Science.gov (United States)

    Reyes-López, J; Nuñez-Jaramillo, L; Morán-Guel, E; Miranda, M I

    2010-08-11

    The medial prefrontal cortex (mPFC) is a brain area crucial for memory, attention, and decision making. Specifically, the noradrenergic system in this cortex is involved in aversive learning, as well as in the retrieval of these memories. Some evidence suggests that this area has an important role during taste memory, particularly during conditioned taste aversion (CTA), a model of aversive memory. Despite some previous evidence, there is scarce information about the role of adrenergic receptors in the mPFC during formation of aversive taste memory and appetitive/incidental taste memory. The goal of this research was to evaluate the role of mPFC beta-adrenergic receptors during CTA acquisition/consolidation or CTA retrieval, as well as during incidental taste memory formation using the model of latent inhibition of CTA. The results showed that infusions in the mPFC of the beta-adrenergic antagonist propranolol before CTA acquisition impaired both short- and long-term aversive taste memory formation, and also that propranolol infusions before the memory test impaired CTA retrieval. However, propranolol infusions before pre-exposure to the taste during the latent inhibition procedure had no effect on incidental taste memory acquisition or consolidation. These data indicate that beta-adrenergic receptors in the mPFC have different functions during taste memory formation: they have an important role during aversive taste association as well as during aversive retrieval but not during incidental taste memory formation. Copyright (c) 2010 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. Cerebral Giant Cells are Necessary for the Formation and Recall of Memory of Conditioned Taste Aversion in Lymnaea.

    Science.gov (United States)

    Sunada, Hiroshi; Lukowiak, Ken; Ito, Etsuro

    2017-02-01

    The pond snail Lymnaea stagnalis can acquire conditioned taste aversion (CTA) as a long-term memory. CTA is caused by the temporal pairing of a stimulus, such as sucrose (the conditioned stimulus; CS), with another stimulus, such as electric shock (the unconditioned stimulus; US). Previous studies have demonstrated changes in both cellular and molecular properties in a pair of neurons known as the cerebral giant cells (CGCs), suggesting that these neurons play a key role in CTA. Here we examined the necessity of the pair of CGC somata for the learning, memory formation and memory recall of CTA by using the soma ablation technique. There was no difference in the feeding response elicited by the CS before and after ablation of the CGC somata. Ablation of the CGC somata before taste-aversion training resulted in the learning acquisition, but the memory formation was not observed 24 h later. We next asked whether memory was present when the CGC somata were ablated 24 h after taste-aversion training. The memory was present before performing the somata ablation. However, when we tested snails five days after somata ablation, the memory recall was not present. Together the data show that: 1) the somata of the CGCs are not necessary for learning acquisition; 2) the somata are necessary for memory formation; and 3) the somata are necessary for memory recall. That is, these results demonstrate that the CGCs function in the long-term memory of CTA in Lymnaea.

  1. Neurocognitive Mechanisms of Prejudice Formation: The Role of Time-Dependent Memory Consolidation.

    Science.gov (United States)

    Enge, Luke R; Lupo, Amber K; Zárate, Michael A

    2015-07-01

    Prejudice is generally thought to derive from learned, emotion-laden experiences. The mechanisms underlying the formation of prejudice over time, however, remain unknown. In the present research, we proposed and tested hypotheses regarding prejudice formation derived from research on memory consolidation and social perception. We hypothesized that time-dependent memory consolidation would produce better implicit memory for negative out-group information and positive in-group information, compared with negative in-group information and positive out-group information. Fifty undergraduates learned positive and negative information about racial in-group (Latino) and out-group (African American) targets. Participants returned after both a short time delay (2-6 hr after the learning session) and a long time delay (48 hr after the learning session) to complete a lexical decision task. Results demonstrated that participants responded to information consistent with an in-group bias faster after a long time delay than after a short time delay. Our findings have important implications for the study of social perception and memory consolidation. © The Author(s) 2015.

  2. Distinct Circuits for the Formation and Retrieval of an Imprinted Olfactory Memory.

    Science.gov (United States)

    Jin, Xin; Pokala, Navin; Bargmann, Cornelia I

    2016-02-11

    Memories formed early in life are particularly stable and influential, representing privileged experiences that shape enduring behaviors. We show that exposing newly hatched C. elegans to pathogenic bacteria results in persistent aversion to those bacterial odors, whereas adult exposure generates only transient aversive memory. Long-lasting imprinted aversion has a critical period in the first larval stage and is specific to the experienced pathogen. Distinct groups of neurons are required during formation (AIB, RIM) and retrieval (AIY, RIA) of the imprinted memory. RIM synthesizes the neuromodulator tyramine, which is required in the L1 stage for learning. AIY memory retrieval neurons sense tyramine via the SER-2 receptor, which is essential for imprinted, but not for adult-learned, aversion. Odor responses in several neurons, most notably RIA, are altered in imprinted animals. These findings provide insight into neuronal substrates of different forms of memory, and lay a foundation for further understanding of early learning. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Region-specific involvement of BDNF secretion and synthesis in conditioned taste aversion memory formation.

    Science.gov (United States)

    Ma, Ling; Wang, Dong-Dong; Zhang, Tian-Yi; Yu, Hui; Wang, Yue; Huang, Shu-Hong; Lee, Francis S; Chen, Zhe-Yu

    2011-02-09

    Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related kinase receptor B (TrkB), play a critical role in activity-dependent plasticity processes such as long-term potentiation, learning, and memory. It has been shown that BDNF exerts different or even opposite effects on behavior depending on the neural circuit. However, the detailed role of BDNF in memory process on the basis of its location has not been fully understood. Here, we aim to investigate the regional specific involvement of BDNF/TrkB in hippocampal-independent conditioned taste aversion (CTA) memory processes. We found region-specific changes in BDNF expression during CTA learning. CTA conditioning induced increased BDNF levels in the central nuclei of amygdala (CeA) and insular cortex, but not in the basolateral amygdala (BLA) and ventromedial prefrontal cortex. Interestingly, we found that the enhanced TrkB phosphorylation occurred at the time point before the increased BDNF expression, suggesting rapid induction of activity-dependent BDNF secretion by CTA learning. Moreover, targeted infusion of BDNF antibodies or BDNF antisense oligonucleotides revealed that activity-dependent BDNF secretion and synthesis in the CeA, but not the BLA, was respectively involved in the short- and long-term memory formation of CTA. Finally, we found that infusion of exogenous BDNF into the CeA could enhance CTA learning. These data suggest that region-specific BDNF release and synthesis temporally regulate different CTA memory phases through activation of TrkB receptors.

  4. A kinase-dependent feedforward loop affects CREBB stability and long term memory formation.

    Science.gov (United States)

    Lee, Pei-Tseng; Lin, Guang; Lin, Wen-Wen; Diao, Fengqiu; White, Benjamin H; Bellen, Hugo J

    2018-02-23

    In Drosophila , long-term memory (LTM) requires the cAMP-dependent transcription factor CREBB, expressed in the mushroom bodies (MB) and phosphorylated by PKA. To identify other kinases required for memory formation, we integrated Trojan exons encoding T2A-GAL4 into genes encoding putative kinases and selected for genes expressed in MB. These lines were screened for learning/memory deficits using UAS-RNAi knockdown based on an olfactory aversive conditioning assay. We identified a novel, conserved kinase, Meng-Po ( MP , CG11221 , SBK1 in human), the loss of which severely affects 3 hr memory and 24 hr LTM, but not learning. Remarkably, memory is lost upon removal of the MP protein in adult MB but restored upon its reintroduction. Overexpression of MP in MB significantly increases LTM in wild-type flies showing that MP is a limiting factor for LTM. We show that PKA phosphorylates MP and that both proteins synergize in a feedforward loop to control CREBB levels and LTM. key words: Drosophila, Mushroom bodies, SBK1, deGradFP, T2A-GAL4, MiMIC.

  5. Void formation in NiTi shape memory alloys by medium-voltage electron irradiation

    International Nuclear Information System (INIS)

    Schlossmacher, P.; Stober, T.

    1995-01-01

    In-situ electron irradiation experiments of NiTi shape memory alloys, using high-voltage transmission electron microscopes, result in amorphization of the intermetallic compound. In all of these experiments high-voltages more than 1.0 MeV had to be applied in order to induce the crystalline-to-amorphous transformation. To their knowledge no irradiation effects of medium-voltage electrons of e.g. 0.5 MeV have been reported in the literature. In this contribution, the authors describe void formation in two different NiTi shape memory alloys, resulting from in-situ electron irradiation, using a 300 kV electron beam in a transmission electron microscope. First evidence is presented that void formation is correlated with the total oxygen content of the alloys

  6. A dϕ-Strategy: Facilitating Dual-Formation Control of a Virtually Connected Team

    Directory of Open Access Journals (Sweden)

    Bibhya Sharma

    2017-01-01

    Full Text Available This paper describes the design of new centralized acceleration-based controllers for the multitask problem of motion planning and control of a coordinated lead-carrier team fixed in a dual-formation within an obstacle-ridden environment. A dϕ-strategy, where d and ϕ are Euclidean measures with respect to the lead robot, is developed to ensure virtual connectivity of the carrier robots to the lead robot. This connectivity, built into the system itself, inherently ensures globally rigid formation between each lead-carrier pair of the team. Moreover, a combination of target configuration, dϕ-strategy, orientation consensus, and avoidance of end-effector of robots results in a second, locally rigid formation (not infinitesimally rigid. Therefore, for the first time, a dual-formation control problem of a lead-carrier team of mobile manipulators is considered. This and other kinodynamic constraints have been treated simultaneously via the overarching Lyapunov-based control scheme, essentially a potential field method favored in the field of robotics. The formulation of this new scheme, demonstrated effectively via computer simulations, is timely, given that the current proposed engineering solutions, allowing autonomous vehicles on public roads, include the development of special lanes imbued with special sensors and wireless technologies.

  7. Hardware format pattern banks for the Associative memory boards in the ATLAS Fast Tracker Trigger System

    CERN Document Server

    Grewcoe, Clay James

    2014-01-01

    The aim of this project is to streamline and update the process of encoding the pattern bank to hardware format in the Associative memory board (AM) of the Fast Tracker (FTK) for the ATLAS detector. The encoding is also adapted to Gray code to eliminate possible misreadings in high frequency devices such as this one, ROOT files are used to store the pattern banks because of the compression utilized in ROOT.

  8. Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees.

    Science.gov (United States)

    de Premorel, Géraud; Giurfa, Martin; Andraud, Christine; Gomez, Doris

    2017-10-25

    Iridescence-change of colour with changes in the angle of view or of illumination-is widespread in the living world, but its functions remain poorly understood. The presence of iridescence has been suggested in flowers where diffraction gratings generate iridescent colours. Such colours have been suggested to serve plant-pollinator communication. Here we tested whether a higher iridescence relative to corolla pigmentation would facilitate discrimination, learning and retention of iridescent visual targets. We conditioned bumblebees ( Bombus terrestris ) to discriminate iridescent from non-iridescent artificial flowers and we varied iridescence detectability by varying target iridescent relative to pigment optical effect. We show that bees rewarded on targets with higher iridescent relative to pigment effect required fewer choices to complete learning, showed faster generalization to novel targets exhibiting the same iridescence-to-pigment level and had better long-term memory retention. Along with optical measurements, behavioural results thus demonstrate that bees can learn iridescence-related cues as bona fide signals for flower reward. They also suggest that floral advertising may be shaped by competition between iridescence and corolla pigmentation, a fact that has important evolutionary implications for pollinators. Optical measurements narrow down the type of cues that bees may have used for learning. Beyond pollinator-plant communication, our experiments help understanding how receivers influence the evolution of iridescence signals generated by gratings. © 2017 The Author(s).

  9. [The effect of encoding on false memory: examination on levels of processing and list presentation format].

    Science.gov (United States)

    Hamajima, Hideki

    2004-04-01

    Using the Deese/Roediger-McDermott paradigm, the effects of lists presentation format (blocked/random) and levels of processing of critical nonpresented lures were examined. A levels-of-processing effect in a blocked presentation order was not observed for lures. Rates of false recognition and remember judgments for lures in a shallow level of processing were significantly lower than those in a deep level of processing when items from various themes were inter-mixed instead of blocked. Results showed an interaction between levels of processing and list presentation format. It is thus concluded that encoding of each word and whole list should be both considered in understanding false memory.

  10. Direct observation of conductive filament formation in Alq3 based organic resistive memories

    Energy Technology Data Exchange (ETDEWEB)

    Busby, Y., E-mail: yan.busby@unamur.be; Pireaux, J.-J. [Research Center in the Physics of Matter and Radiation (PMR), Laboratoire Interdisciplinaire de Spectroscopie Electronique (LISE), University of Namur, B-5000 Namur (Belgium); Nau, S.; Sax, S. [NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler Straße 32, A-8160 Weiz (Austria); List-Kratochvil, E. J. W. [NanoTecCenter Weiz Forschungsgesellschaft mbH, Franz-Pichler Straße 32, A-8160 Weiz (Austria); Institute of Solid State Physics, Graz University of Technology, A-8010 Graz (Austria); Novak, J.; Banerjee, R.; Schreiber, F. [Institute of Applied Physics, Eberhard-Karls-Universität Tübingen, D-72076 Tübingen (Germany)

    2015-08-21

    This work explores resistive switching mechanisms in non-volatile organic memory devices based on tris(8-hydroxyquinolie)aluminum (Alq{sub 3}). Advanced characterization tools are applied to investigate metal diffusion in ITO/Alq{sub 3}/Ag memory device stacks leading to conductive filament formation. The morphology of Alq{sub 3}/Ag layers as a function of the metal evaporation conditions is studied by X-ray reflectivity, while depth profile analysis with X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry is applied to characterize operational memory elements displaying reliable bistable current-voltage characteristics. 3D images of the distribution of silver inside the organic layer clearly point towards the existence of conductive filaments and allow for the identification of the initial filament formation and inactivation mechanisms during switching of the device. Initial filament formation is suggested to be driven by field assisted diffusion of silver from abundant structures formed during the top electrode evaporation, whereas thermochemical effects lead to local filament inactivation.

  11. Nitrogen remobilisation facilitates adventitious root formation on reversible dark-induced carbohydrate depletion in Petunia hybrida

    OpenAIRE

    Zerche, Siegfried; Haensch, Klaus-Thomas; Druege, Uwe; Hajirezaei, Mohammad-Reza

    2016-01-01

    Background Adventitious root (AR) formation in axillary shoot tip cuttings is a crucial physiological process for ornamental propagation that is utilised in global production chains for young plants. In this process, the nitrogen and carbohydrate metabolisms of a cutting are regulated by its total nitrogen content (Nt), dark exposure during transport and irradiance levels at distinct production sites and phases through a specific plasticity to readjust metabolite pools. Here, we examined how ...

  12. Melanocortin Receptor Agonists Facilitate Oxytocin-Dependent Partner Preference Formation in the Prairie Vole.

    Science.gov (United States)

    Modi, Meera E; Inoue, Kiyoshi; Barrett, Catherine E; Kittelberger, Kara A; Smith, Daniel G; Landgraf, Rainer; Young, Larry J

    2015-07-01

    The central melanocortin (MC) system has been widely studied for its effects on food intake and sexual behavior. However, the MC system, and more specifically the MC4 receptor (MC4R), also interacts with neurochemical systems that regulate socioemotional behaviors, including oxytocin (OT) and dopamine. In monogamous prairie voles, OT and dopamine interact to promote partner preference formation, a laboratory measure of an enduring social bond between mates. Here we investigated the effects of MC receptor activation on partner preference formation in prairie voles, as well as the interaction between the MC and OT systems during this process. Peripheral administration of the brain penetrant MC3/4R receptor peptide agonist, Melanotan II (MTII), and the highly selective, small-molecule MC4R agonist, Pf-446687, enhanced partner preference formation in the prairie vole, but not in the non-monogamous meadow vole. MTII-induced partner preferences were enduring, as they were present 1 week after drug manipulation. The prosocial effects of MCR agonists may be mediated, in part, through modulation of OT, as coadministration of an OT receptor antagonist prevented MTII-induced partner preferences. MTII also selectively activated hypothalamic OT neurons and potentiated central OT release. As OT has been shown to enhance some aspects of social cognition in humans, our data suggest that the MC4R may be a viable therapeutic target for enhancing social function in psychiatric disorders, including autism spectrum disorders and schizophrenia, potentially through activation of the OT system.

  13. Distinct effects of perceptual quality on auditory word recognition, memory formation and recall in a neural model of sequential memory

    Directory of Open Access Journals (Sweden)

    Paul Miller

    2010-06-01

    Full Text Available Adults with sensory impairment, such as reduced hearing acuity, have impaired ability to recall identifiable words, even when their memory is otherwise normal. We hypothesize that poorer stimulus quality causes weaker activity in neurons responsive to the stimulus and more time to elapse between stimulus onset and identification. The weaker activity and increased delay to stimulus identification reduce the necessary strengthening of connections between neurons active before stimulus presentation and neurons active at the time of stimulus identification. We test our hypothesis through a biologically motivated computational model, which performs item recognition, memory formation and memory retrieval. In our simulations, spiking neurons are distributed into pools representing either items or context, in two separate, but connected winner-takes-all (WTA networks. We include associative, Hebbian learning, by comparing multiple forms of spike-timing dependent plasticity (STDP, which strengthen synapses between coactive neurons during stimulus identification. Synaptic strengthening by STDP can be sufficient to reactivate neurons during recall if their activity during a prior stimulus rose strongly and rapidly. We find that a single poor quality stimulus impairs recall of neighboring stimuli as well as the weak stimulus itself. We demonstrate that within the WTA paradigm of word recognition, reactivation of separate, connected sets of non-word, context cells permits reverse recall. Also, only with such coactive context cells, does slowing the rate of stimulus presentation increase recall probability. We conclude that significant temporal overlap of neural activity patterns, absent from individual WTA networks, is necessary to match behavioral data for word recall.

  14. Altered gene activity correlated with long-term memory formation of conditioned taste aversion in Lymnaea.

    Science.gov (United States)

    Azami, Sachiyo; Wagatsuma, Akiko; Sadamoto, Hisayo; Hatakeyama, Dai; Usami, Takeshi; Fujie, Manabu; Koyanagi, Ryo; Azumi, Kaoru; Fujito, Yutaka; Lukowiak, Ken; Ito, Etsuro

    2006-11-15

    The pond snail Lymnaea stagnalis is capable of learning conditioned taste aversion (CTA) and then consolidating that learning into long-term memory (LTM) that persists for at least 1 month. LTM requires de novo protein synthesis and altered gene activity. Changes in gene activity in Lymnaea that are correlated with, much less causative, memory formation have not yet been identified. As a first step toward rectifying this situation, we constructed a cDNA microarray with mRNAs extracted from the central nervous system (CNS) of Lymnaea. We then, using this microarray assay, identified genes whose activity either increased or decreased following CTA memory consolidation. We also identified genes whose expression levels were altered after inhibition of the cyclic AMP response element-binding protein (CREB) that is hypothesized to be a key transcription factor for CTA memory. We found that the molluscan insulin-related peptide II (MIP II) was up-regulated during CTA-LTM, whereas the gene encoding pedal peptide preprohormone (Pep) was down-regulated by CREB2 RNA interference. We next examined mRNAs of MIP II and Pep using real-time RT-PCR with SYBR Green. The MIP II mRNA level in the CNS of snails exhibiting "good" memory for CTA was confirmed to be significantly higher than that from the CNS of snails exhibiting "poor" memory. In contrast, there was no significant difference in expression levels of the Pep mRNA between "good" and "poor" performers. These data suggest that in Lymnaea MIP II may play a role in the consolidation process that forms LTM following CTA training.

  15. MSL: Facilitating automatic and physical analysis of published scientific literature in PDF format.

    Science.gov (United States)

    Ahmed, Zeeshan; Dandekar, Thomas

    2015-01-01

    Published scientific literature contains millions of figures, including information about the results obtained from different scientific experiments e.g. PCR-ELISA data, microarray analysis, gel electrophoresis, mass spectrometry data, DNA/RNA sequencing, diagnostic imaging (CT/MRI and ultrasound scans), and medicinal imaging like electroencephalography (EEG), magnetoencephalography (MEG), echocardiography  (ECG), positron-emission tomography (PET) images. The importance of biomedical figures has been widely recognized in scientific and medicine communities, as they play a vital role in providing major original data, experimental and computational results in concise form. One major challenge for implementing a system for scientific literature analysis is extracting and analyzing text and figures from published PDF files by physical and logical document analysis. Here we present a product line architecture based bioinformatics tool 'Mining Scientific Literature (MSL)', which supports the extraction of text and images by interpreting all kinds of published PDF files using advanced data mining and image processing techniques. It provides modules for the marginalization of extracted text based on different coordinates and keywords, visualization of extracted figures and extraction of embedded text from all kinds of biological and biomedical figures using applied Optimal Character Recognition (OCR). Moreover, for further analysis and usage, it generates the system's output in different formats including text, PDF, XML and images files. Hence, MSL is an easy to install and use analysis tool to interpret published scientific literature in PDF format.

  16. Using Dopants to Tune Oxygen Vacancy Formation in Transition Metal Oxide Resistive Memory.

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A

    2017-05-17

    Introducing dopants is an important way to tailor and improve electronic properties of transition metal oxides used as high-k dielectric thin films and resistance switching layers in leading memory technologies, such as dynamic and resistive random access memory (ReRAM). Ta 2 O 5 has recently received increasing interest because Ta 2 O 5 -based ReRAM demonstrates high switching speed, long endurance, and low operating voltage. However, advances in optimizing device characteristics with dopants have been hindered by limited and contradictory experiments in this field. We report on a systematic study on how various metal dopants affect oxygen vacancy formation in crystalline and amorphous Ta 2 O 5 from first principles. We find that isoelectronic dopants and weak n-type dopants have little impact on neutral vacancy formation energy and that p-type dopants can lower the formation energy significantly by introducing holes into the system. In contrast, n-type dopants have a deleterious effect and actually increase the formation energy for charged oxygen vacancies. Given the similar doping trend reported for other binary transition metal oxides, this doping trend should be universally valid for typical binary transition metal oxides. Based on this guideline, we propose that p-type dopants (Al, Hf, Zr, and Ti) can lower the forming/set voltage and improve retention properties of Ta 2 O 5 ReRAM.

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

    Science.gov (United States)

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

    2009-01-01

    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…

  18. Memory

    Science.gov (United States)

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  19. Employing Computer Assisted Assessment (CAA to facilitate formative assessment in the State Secondary School: a case study

    Directory of Open Access Journals (Sweden)

    Effimia Karagianni

    2012-02-01

    Full Text Available Based on theories of assessment as well as on the pedagogical and administrative advantages Computer Assisted Assessment (CAA has to offer in foreign language learning, the study presented in this paper examines how computers can facilitate the formative assessment of EFL learners and enhance their feeling of responsibility towards monitoring their progress. The subjects of the study were twenty five 14-year-old students attending the third class of a State Gymnasium in Greece. The instruments utilized were questionnaires on motivation and learning styles, three quizzes designed with the software Hot Potatoes, a self–assessment questionnaire and an evaluation questionnaire showing the subjects’ attitudes towards the experience of using computers for assessing purposes. After reviewing formative assessment, CAA and how these two can be combined, the paper focuses on the description of the three class quizzes used in the study. Ιnformation from the questionnaires filled in by students combined with the results of the quizzes, shows how computers can be used to provide continuous ongoing measurement of students’ progress needed for formative assessment. The results are also used to show how students and teachers can benefit from formative CAA and the extent to which such kind of assessment could be applicable in the Greek state school reality.

  20. Low-power resistive random access memory by confining the formation of conducting filaments

    International Nuclear Information System (INIS)

    Huang, Yi-Jen; Lee, Si-Chen; Shen, Tzu-Hsien; Lee, Lan-Hsuan; Wen, Cheng-Yen

    2016-01-01

    Owing to their small physical size and low power consumption, resistive random access memory (RRAM) devices are potential for future memory and logic applications in microelectronics. In this study, a new resistive switching material structure, TiO_x/silver nanoparticles/TiO_x/AlTiO_x, fabricated between the fluorine-doped tin oxide bottom electrode and the indium tin oxide top electrode is demonstrated. The device exhibits excellent memory performances, such as low operation voltage (<±1 V), low operation power, small variation in resistance, reliable data retention, and a large memory window. The current-voltage measurement shows that the conducting mechanism in the device at the high resistance state is via electron hopping between oxygen vacancies in the resistive switching material. When the device is switched to the low resistance state, conducting filaments are formed in the resistive switching material as a result of accumulation of oxygen vacancies. The bottom AlTiO_x layer in the device structure limits the formation of conducting filaments; therefore, the current and power consumption of device operation are significantly reduced.

  1. Neuroepigenetics of memory formation and impairment: the role of microRNAs.

    Science.gov (United States)

    Saab, Bechara J; Mansuy, Isabelle M

    2014-05-01

    MicroRNAs (miRNAs) are a class of short non-coding RNAs that primarily regulate protein synthesis through reversible translational repression or mRNA degradation. MiRNAs can act by translational control of transcription factors or via direct action on the chromatin, and thereby contribute to the non-genetic control of gene-environment interactions. MiRNAs that regulate components of pathways required for learning and memory further modulate the influence of epigenetics on cognition in the normal and diseased brain. This review summarizes recent data exemplifying the known roles of miRNAs in memory formation in different model organisms, and describes how neuronal plasticity regulates miRNA biogenesis, activity and degradation. It also examines the relevance of miRNAs for memory impairment in human, using recent clinical observations related to neurodevelopmental and neurodegenerative diseases, and discusses the potential mechanisms by which these miRNAs may contribute to memory disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. How the bimodal format of presentation affects working memory: an overview.

    Science.gov (United States)

    Mastroberardino, Serena; Santangelo, Valerio; Botta, Fabiano; Marucci, Francesco S; Olivetti Belardinelli, Marta

    2008-03-01

    The best format in which information that has to be recalled is presented has been investigated in several studies, which focused on the impact of bimodal stimulation on working memory performance. An enhancement of participant's performance in terms of correct recall has been repeatedly found, when bimodal formats of presentation (i.e., audiovisual) were compared to unimodal formats (i.e, either visual or auditory), in providing implications for multimedial learning. Several theoretical frameworks have been suggested in order to account for the bimodal advantage, ranging from those emphasizing early stages of processing (such as automatic alerting effects or multisensory integration processes) to those centred on late stages of processing (as postulated by the dual coding theory). The aim of this paper is to review previous contributions to this topic, providing a comprehensive theoretical framework, which is updated by the latest empirical studies.

  3. Rho-associated kinase in the gustatory cortex is involved in conditioned taste aversion memory formation but not in memory retrieval or relearning.

    Science.gov (United States)

    Sweetat, Sahar; Rosenblum, Kobi; Lamprecht, Raphael

    2012-01-01

    Rho-associated kinase (ROCK) is intimately involved in cortical neuronal morphogenesis. The present study explores the roles of ROCK in conditioned taste aversion (CTA) memory formation in gustatory cortex (GC) in adult rat. Microinjection of the ROCK inhibitor Y-27632 into the GC 30 min before CTA training or 10 min after the conditioned stimulus (CS) impaired long-term CTA memory (LTM) formation. ROCK inhibitor had no effect on taste aversion when injected before the first LTM test day and did not alter taste aversion on subsequent test days. Microinjection of ROCK inhibitor into GC 30 min before preexposure to the taste CS had no effect on latent inhibition of CTA learning suggesting that ROCK is involved in CS-US association rather than taste learning per se. Cumulatively, these results show that ROCK is needed for normal CTA memory formation but not retrieval, relearning or incidental taste learning. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Activity dependent protein degradation is critical for the formation and stability of fear memory in the amygdala.

    Directory of Open Access Journals (Sweden)

    Timothy J Jarome

    Full Text Available Protein degradation through the ubiquitin-proteasome system [UPS] plays a critical role in some forms of synaptic plasticity. However, its role in memory formation in the amygdala, a site critical for the formation of fear memories, currently remains unknown. Here we provide the first evidence that protein degradation through the UPS is critically engaged at amygdala synapses during memory formation and retrieval. Fear conditioning results in NMDA-dependent increases in degradation-specific polyubiquitination in the amygdala, targeting proteins involved in translational control and synaptic structure and blocking the degradation of these proteins significantly impairs long-term memory. Furthermore, retrieval of fear memory results in a second wave of NMDA-dependent polyubiquitination that targets proteins involved in translational silencing and synaptic structure and is critical for memory updating following recall. These results indicate that UPS-mediated protein degradation is a major regulator of synaptic plasticity necessary for the formation and stability of long-term memories at amygdala synapses.

  5. Roles of aminergic neurons in formation and recall of associative memory in crickets

    Directory of Open Access Journals (Sweden)

    Makoto Mizunami

    2010-11-01

    Full Text Available We review recent progress in the study of roles of octopaminergic (OA-ergic and dopaminergic (DA-ergic signaling in insect classical conditioning, focusing on our studies on crickets. Studies on olfactory learning in honey bees and fruit-flies have suggested that OA-ergic and DA-ergic neurons convey reinforcing signals of appetitive unconditioned stimulus (US and aversive US, respectively. Our work suggested that this is applicable to olfactory, visual pattern and color learning in crickets, indicating that this feature is ubiquitous in learning of various sensory stimuli. We also showed that aversive memory decayed much faster than did appetitive memory, and we proposed that this feature is common in insects and humans. Our study also suggested that activation of OA- or DA-ergic neurons is needed for appetitive or aversive memory recall, respectively. To account for this finding, we proposed a model in which it is assumed that two types of synaptic connections are strengthened by conditioning and are activated during memory recall, one type being connections from neurons representing conditioned stimulus (CS to neurons inducing conditioned response and the other being connections from neurons representing CS to OA- or DA-ergic neurons representing appetitive or aversive US, respectively. The former is called stimulus-response (S-R connection and the latter is called stimulus-stimulus (S-S connection by theorists studying classical conditioning in vertebrates. Results of our studies using a second-order conditioning procedure supported our model. We propose that insect classical conditioning involves the formation of S-S connection and its activation for memory recall, which are often called cognitive processes.

  6. Rottlerin impairs the formation and maintenance of psychostimulant-supported memory.

    Science.gov (United States)

    Liao, Tien You; Tzeng, Wen-Yu; Wu, Hsin-Hua; Cherng, Chianfang G; Wang, Ching-Yi; Hu, Sherry S-J; Yu, Lung

    2016-04-01

    Since brain proteins such as protein kinase C (PKC), brain-derived neurotrophic factor (BDNF), and mammalian target of rapamycin (mTOR) are involved in the establishment and maintenance of psychostimulant memory, we sought to determine if systemic treatment with rottlerin, a natural compound affecting all these proteins, may modulate stimulant-supported memory. Stimulant-induced conditioned place preference (CPP) was used in modeling stimulant-supported memory. Three cocaine (10 mg/kg; COC) or three methamphetamine (1 mg/kg; MA) conditioning trials reliably established the drug-induced CPP in male C57BL/6 mice. An intra-peritoneal rottlerin injection (5 mg/kg) at least 24 h prior to the first COC or first MA conditioning trial prevented the establishment of CPP. Following the establishment of the COC- or MA-induced CPP, saline conditioning trial was used to extinguish the CPP. Rottlerin (5 mg/kg, intra-peritoneal (i.p.)) administered 20 h prior to the first saline conditioning trial diminished subsequent drug- and stressor-primed reinstatement of the extinguished CPP. Rottlerin (5 mg/kg, i.p.) produced a fast-onset and long-lasting increase in hippocampal BDNF levels. However, treatment with a BDNF tropomyosin receptor kinase B (TrkB) receptor antagonist, K252a (5 μg/kg), did not affect rottlerin's suppressing effect on COC-induced CPP and treatment with 7,8-dihydroxyflavone (10 mg/kg x 6, 7,8-DHF), a selective TrkB agonist, prior to each conditioning trial did not affect COC-induced CPP. These results suggest that systemic rottlerin treatment may impair the formation of COC- and MA-supported memory. Importantly, such a treatment may advance our understanding of the underlying mechanism through which extinction training resulted in the "forgetting" of the COC- and MA-supported memory.

  7. Object properties and cognitive load in the formation of associative memory during precision lifting.

    Science.gov (United States)

    Li, Yong; Randerath, Jennifer; Bauer, Hans; Marquardt, Christian; Goldenberg, Georg; Hermsdörfer, Joachim

    2009-01-03

    When we manipulate familiar objects in our daily life, our grip force anticipates the physical demands right from the moment of contact with the object, indicating the existence of a memory for relevant object properties. This study explores the formation and consolidation of the memory processes that associate either familiar (size) or arbitrary object features (color) with object weight. In the general task, participants repetitively lifted two differently weighted objects (580 and 280 g) in a pseudo-random order. Forty young healthy adults participated in this study and were randomly distributed into four groups: Color Cue Single task (CCS, blue and red, 9.8(3)cm(3)), Color Cue Dual task (CCD), No Cue (NC) and Size Cue (SC, 9.8(3) and 6(3)cm(3)) group. All groups performed a repetitive precision grasp-lift task and were retested with the same protocol after a 5-min pause. The CCD group was also required to simultaneously perform a memory task during each lift of differently weighted objects coded by color. The results show that groups lifting objects with arbitrary or familiar features successfully formed the association between object weight and manipulated object features and incorporated this into grip force programming, as observed in the different scaling of grip force and grip force rate for different object weights. An arbitrary feature, i.e., color, can be sufficiently associated with object weight, however with less strength than the familiar feature of size. The simultaneous memory task impaired anticipatory force scaling during repetitive object lifting but did not jeopardize the learning process and the consolidation of the associative memory.

  8. The Role of Cannabinoid Transmission in Emotional Memory Formation: Implications for Addiction and Schizophrenia

    Directory of Open Access Journals (Sweden)

    Huibing eTan

    2014-06-01

    Full Text Available Emerging evidence from both basic and clinical research demonstrates an important role for endocannabinoid (ECB signaling in the processing of emotionally salient information, learning and memory. Cannabinoid transmission within neural circuits involved in emotional processing has been shown to modulate the acquisition, recall and extinction of emotionally salient memories and importantly, can strongly modulate the emotional salience of incoming sensory information. Two neural regions in particular, the medial prefrontal cortex (PFC and the basolateral nucleus of the amygdala (BLA, play important roles in emotional regulation and contain high levels of cannabinoid receptors. Furthermore, both regions show profound abnormalities in neuropsychiatric disorders such as addiction and schizophrenia. Considerable evidence has demonstrated that cannabinoid transmission functionally interacts with dopamine (DA, a neurotransmitter system that is of exceptional importance for both addictive behaviours and the neuropsychopathology of disorders like schizophrenia. Research in our laboratory has focused on how cannabinoid transmission both within and extrinsic to the mesolimbic DA system, including the BLAmPFC circuitry, can modulate both rewarding and aversive emotional information. In this review, we will summarize clinical and basic neuroscience research demonstrating the importance of cannabinoid signaling within this neural circuitry. In particular, evidence will be reviewed emphasizing the importance of cannabinoid signaling within the BLAmPFC circuitry in the context of emotional salience processing, memory formation and memory-related plasticity. We propose that aberrant states of hyper or hypoactive ECB signaling within the amygdala-prefrontal cortical circuit may lead to dysregulation of mesocorticolimbic DA transmission controlling the processing of emotionally salient information. These disturbances may in turn lead to emotional processing

  9. CDK1 inhibition facilitates formation of syncytiotrophoblasts and expression of human Chorionic Gonadotropin

    KAUST Repository

    Ullah, Rahim

    2018-05-17

    Aims The human placental syncytiotrophoblast (STB) cells play essential roles in embryo implantation and nutrient exchange between the mother and the fetus. STBs are polyploid which are formed by fusion of diploid cytotrophoblast (CTB) cells. Abnormality in STBs formation can result in pregnancy-related disorders. While a number of genes have been associated with CTB fusion the initial events that trigger cell fusion are not well understood. Primary objective of this study was to enhance our understanding about the molecular mechanism of placental cell fusion. Methods FACS and microscopic analysis was used to optimize Forskolin-induced fusion of BeWo cells (surrogate of CTBs) and subsequently, changes in the expression of different cell cycle regulator genes were analyzed through Western blotting and qPCR. Immunohistochemistry was performed on the first trimester placental tissue sections to validate the results in the context of placental tissue. Effect of Cyclin Dependent Kinase 1 (CDK1) inhibitor, RO3306, on BeWo cell fusion was studied by microscopy and FACS, and by monitoring the expression of human Chorionic Gonadotropin (hCG) by Western blotting and qPCR. Results The data showed that the placental cell fusion was associated with down regulation of CDK1 and its associated cyclin B, and significant decrease in DNA replication. Moreover, inhibition of CDK1 by an exogenous inhibitor induced placental cell fusion and expression of hCG. Conclusion Here, we report that the placental cell fusion can be induced by inhibiting CDK1. This study has a high therapeutic significance to manage pregnancy related abnormalities.

  10. Hydrotalcite formation facilitates effective contaminant and radionuclide removal from acidic uranium mine barren lixiviant

    International Nuclear Information System (INIS)

    Douglas, Grant; Shackleton, Mark; Woods, Peter

    2014-01-01

    Highlights: • Remediation of barren lixiviant using hydrotalcite precipitation. • High U and rare earth element concentration factor. • Hydrotalcite may be further modified for long-term disposal. • Potential application to U and other commodities. - Abstract: An assessment of hydrotalcite (HT) formation as a method to neutralise acidity and remove trace elements was undertaken using barren lixiviant from Heathgate Resources’ Beverley North in situ recovery (ISR) U mine in South Australia. This study demonstrated proof of concept in terms of the neutralisation of acidity and concomitant removal of a range of trace elements and U–Th series radionuclides from the barren lixiviant using MgCl 2 as a supplementary Mg source to optimise Mg:Al mol ratios and NaOH as the neutralising agent. Hydrotalcite was the predominant mineral formed during neutralisation, hosting a range of elements including substantial U (∼0.2%) and rare earth elements (REE ∼0.1%). High U and REE recovery (∼99%) from barren lixiviant after HT precipitation indicates a potential to both remediate barren lixiviant and to offset remediation costs. Alternatively, HT precipitates formed during barren lixiviant neutralisation may be further stabilised via calcination, silicification or a combination thereof forming minerals potentially amenable for inclusion in a long-term waste repository at the cessation of ISR mining. Importantly, the composition of the neutralised barren lixiviant produced via HT precipitation is similar to that of existing groundwater allowing for the possibility of direct aquifer re-injection after remediation. A potential exists to apply this HT-based remediation technology to conventional or ISR U mines (or mines exploiting other commodities) and allows for the prospect of a fully integrated ISR mining, processing and lixiviant remediation strategy consistent with stringent environmental and mine closure standards

  11. How memory of direct animal interactions can lead to territorial pattern formation.

    Science.gov (United States)

    Potts, Jonathan R; Lewis, Mark A

    2016-05-01

    Mechanistic home range analysis (MHRA) is a highly effective tool for understanding spacing patterns of animal populations. It has hitherto focused on populations where animals defend their territories by communicating indirectly, e.g. via scent marks. However, many animal populations defend their territories using direct interactions, such as ritualized aggression. To enable application of MHRA to such populations, we construct a model of direct territorial interactions, using linear stability analysis and energy methods to understand when territorial patterns may form. We show that spatial memory of past interactions is vital for pattern formation, as is memory of 'safe' places, where the animal has visited but not suffered recent territorial encounters. Additionally, the spatial range over which animals make decisions to move is key to understanding the size and shape of their resulting territories. Analysis using energy methods, on a simplified version of our system, shows that stability in the nonlinear system corresponds well to predictions of linear analysis. We also uncover a hysteresis in the process of territory formation, so that formation may depend crucially on initial space-use. Our analysis, in one dimension and two dimensions, provides mathematical groundwork required for extending MHRA to situations where territories are defended by direct encounters. © 2016 The Author(s).

  12. Learning to learn - intrinsic plasticity as a metaplasticity mechanism for memory formation.

    Science.gov (United States)

    Sehgal, Megha; Song, Chenghui; Ehlers, Vanessa L; Moyer, James R

    2013-10-01

    "Use it or lose it" is a popular adage often associated with use-dependent enhancement of cognitive abilities. Much research has focused on understanding exactly how the brain changes as a function of experience. Such experience-dependent plasticity involves both structural and functional alterations that contribute to adaptive behaviors, such as learning and memory, as well as maladaptive behaviors, including anxiety disorders, phobias, and posttraumatic stress disorder. With the advancing age of our population, understanding how use-dependent plasticity changes across the lifespan may also help to promote healthy brain aging. A common misconception is that such experience-dependent plasticity (e.g., associative learning) is synonymous with synaptic plasticity. Other forms of plasticity also play a critical role in shaping adaptive changes within the nervous system, including intrinsic plasticity - a change in the intrinsic excitability of a neuron. Intrinsic plasticity can result from a change in the number, distribution or activity of various ion channels located throughout the neuron. Here, we review evidence that intrinsic plasticity is an important and evolutionarily conserved neural correlate of learning. Intrinsic plasticity acts as a metaplasticity mechanism by lowering the threshold for synaptic changes. Thus, learning-related intrinsic changes can facilitate future synaptic plasticity and learning. Such intrinsic changes can impact the allocation of a memory trace within a brain structure, and when compromised, can contribute to cognitive decline during the aging process. This unique role of intrinsic excitability can provide insight into how memories are formed and, more interestingly, how neurons that participate in a memory trace are selected. Most importantly, modulation of intrinsic excitability can allow for regulation of learning ability - this can prevent or provide treatment for cognitive decline not only in patients with clinical disorders but

  13. Learning to learn – intrinsic plasticity as a metaplasticity mechanism for memory formation

    Science.gov (United States)

    Sehgal, Megha; Song, Chenghui; Ehlers, Vanessa L.; Moyer, James R.

    2013-01-01

    “Use it or lose it” is a popular adage often associated with use-dependent enhancement of cognitive abilities. Much research has focused on understanding exactly how the brain changes as a function of experience. Such experience-dependent plasticity involves both structural and functional alterations that contribute to adaptive behaviors, such as learning and memory, as well as maladaptive behaviors, including anxiety disorders, phobias, and posttraumatic stress disorder. With the advancing age of our population, understanding how use-dependent plasticity changes across the lifespan may also help to promote healthy brain aging. A common misconception is that such experience-dependent plasticity (e.g., associative learning) is synonymous with synaptic plasticity. Other forms of plasticity also play a critical role in shaping adaptive changes within the nervous system, including intrinsic plasticity – a change in the intrinsic excitability of a neuron. Intrinsic plasticity can result from a change in the number, distribution or activity of various ion channels located throughout the neuron. Here, we review evidence that intrinsic plasticity is an important and evolutionarily conserved neural correlate of learning. Intrinsic plasticity acts as a metaplasticity mechanism by lowering the threshold for synaptic changes. Thus, learning-related intrinsic changes can facilitate future synaptic plasticity and learning. Such intrinsic changes can impact the allocation of a memory trace within a brain structure, and when compromised, can contribute to cognitive decline during the aging process. This unique role of intrinsic excitability can provide insight into how memories are formed and, more interestingly, how neurons that participate in a memory trace are selected. Most importantly, modulation of intrinsic excitability can allow for regulation of learning ability – this can prevent or provide treatment for cognitive decline not only in patients with clinical

  14. Imposed Environmental Stresses Facilitate Cell-Free Nanoparticle Formation by Deinococcus radiodurans.

    Science.gov (United States)

    Chen, Angela; Contreras, Lydia M; Keitz, Benjamin K

    2017-09-15

    have been utilized for nanoparticle formation. The extremophile D. radiodurans , which can withstand significant environmental stresses and therefore is more robust for metal reduction applications, has yet to be exploited for this purpose. Thus, this work improves our understanding of the impact of environmental stresses on biogenic nanoparticle morphology and composition during metal reduction processes in this organism. This work also contributes to enhancing the controlled synthesis of nanoparticles with specific attributes and functions using biological systems. Copyright © 2017 American Society for Microbiology.

  15. Interactions of nitric oxide with α2‐adrenoceptors within the locus coeruleus underlie the facilitation of inhibitory avoidance memory by agmatine

    Science.gov (United States)

    Shelkar, Gajanan P; Gakare, Sukanya G; Chakraborty, Suwarna; Dravid, Shashank M

    2016-01-01

    Background and Purpose Agmatine, a putative neurotransmitter, plays a vital role in learning and memory. Although it is considered an endogenous ligand of imidazoline receptors, agmatine exhibits high affinity for α‐adrenoceptors, NOS and NMDA receptors. These substrates within the locus coeruleus (LC) are critically involved in learning and memory processes. Experimental Approach The hippocampus and LC of male Wistar rat were stereotaxically cannulated for injection. Effects of agmatine, given i.p. or intra‐LC, on acquisition, consolidation and retrieval of inhibitory avoidance (IA) memory were measured. The NO donor S‐nitrosoglutathione, non‐specific (L‐NAME) and specific NOS inhibitors (L‐NIL, 7‐NI, L‐NIO), the α2‐adrenoceptor antagonist (yohimbine) or the corresponding agonist (clonidine) were injected intra‐LC before agmatine. Intra‐hippocampal injections of the NMDA antagonist, MK‐801 (dizocilpine), were used to modify the memory enhancing effects of agmatine, SNG and yohimbine. Expression of tyrosine hydroxylase (TH) and eNOS in the LC was assessed immunohistochemically. Key Results Agmatine (intra‐LC or i.p.) facilitated memory retrieval in the IA test. S‐nitrosoglutathione potentiated, while L‐NAME and L‐NIO decreased, these effects of agmatine. L‐NIL and 7‐NI did not alter the effects of agmatine. Yohimbine potentiated, whereas clonidine attenuated, effects of agmatine within the LC. The effects of agmatine, S‐nitrosoglutathione and yohimbine were blocked by intra‐hippocampal MK‐801. Agmatine increased the population of TH‐ and eNOS‐immunoreactive elements in the LC. Conclusions and Implications The facilitation of memory retrieval in the IA test by agmatine is probably mediated by interactions between eNOS, NO and noradrenergic pathways in the LC. PMID:27273730

  16. Interactions of nitric oxide with α2 -adrenoceptors within the locus coeruleus underlie the facilitation of inhibitory avoidance memory by agmatine.

    Science.gov (United States)

    Shelkar, Gajanan P; Gakare, Sukanya G; Chakraborty, Suwarna; Dravid, Shashank M; Ugale, Rajesh R

    2016-09-01

    Agmatine, a putative neurotransmitter, plays a vital role in learning and memory. Although it is considered an endogenous ligand of imidazoline receptors, agmatine exhibits high affinity for α-adrenoceptors, NOS and NMDA receptors. These substrates within the locus coeruleus (LC) are critically involved in learning and memory processes. The hippocampus and LC of male Wistar rat were stereotaxically cannulated for injection. Effects of agmatine, given i.p. or intra-LC, on acquisition, consolidation and retrieval of inhibitory avoidance (IA) memory were measured. The NO donor S-nitrosoglutathione, non-specific (L-NAME) and specific NOS inhibitors (L-NIL, 7-NI, L-NIO), the α2 -adrenoceptor antagonist (yohimbine) or the corresponding agonist (clonidine) were injected intra-LC before agmatine. Intra-hippocampal injections of the NMDA antagonist, MK-801 (dizocilpine), were used to modify the memory enhancing effects of agmatine, SNG and yohimbine. Expression of tyrosine hydroxylase (TH) and eNOS in the LC was assessed immunohistochemically. Agmatine (intra-LC or i.p.) facilitated memory retrieval in the IA test. S-nitrosoglutathione potentiated, while L-NAME and L-NIO decreased, these effects of agmatine. L-NIL and 7-NI did not alter the effects of agmatine. Yohimbine potentiated, whereas clonidine attenuated, effects of agmatine within the LC. The effects of agmatine, S-nitrosoglutathione and yohimbine were blocked by intra-hippocampal MK-801. Agmatine increased the population of TH- and eNOS-immunoreactive elements in the LC. The facilitation of memory retrieval in the IA test by agmatine is probably mediated by interactions between eNOS, NO and noradrenergic pathways in the LC. © 2016 The British Pharmacological Society.

  17. A Memory/Immunology-Based Control Approach with Applications to Multiple Spacecraft Formation Flying

    Directory of Open Access Journals (Sweden)

    Liguo Weng

    2013-01-01

    Full Text Available This paper addresses the problem of formation control for multiple spacecrafts in Planetary Orbital Environment (POE. Due to the presence of diverse interferences and uncertainties in the outer space, such as the changing spacecraft mass, unavailable space parameters, and varying gravity forces, traditional control methods encounter great difficulties in this area. A new control approach inspired by human memory and immune system is proposed, and this approach is shown to be capable of learning from past control experience and current behavior to improve its performance. It demands much less system dynamic information as compared with traditional controls. Both theoretic analysis and computer simulation verify its effectiveness.

  18. Reward signal in a recurrent circuit drives appetitive long-term memory formation.

    Science.gov (United States)

    Ichinose, Toshiharu; Aso, Yoshinori; Yamagata, Nobuhiro; Abe, Ayako; Rubin, Gerald M; Tanimoto, Hiromu

    2015-11-17

    Dopamine signals reward in animal brains. A single presentation of a sugar reward to Drosophila activates distinct subsets of dopamine neurons that independently induce short- and long-term olfactory memories (STM and LTM, respectively). In this study, we show that a recurrent reward circuit underlies the formation and consolidation of LTM. This feedback circuit is composed of a single class of reward-signaling dopamine neurons (PAM-α1) projecting to a restricted region of the mushroom body (MB), and a specific MB output cell type, MBON-α1, whose dendrites arborize that same MB compartment. Both MBON-α1 and PAM-α1 neurons are required during the acquisition and consolidation of appetitive LTM. MBON-α1 additionally mediates the retrieval of LTM, which is dependent on the dopamine receptor signaling in the MB α/β neurons. Our results suggest that a reward signal transforms a nascent memory trace into a stable LTM using a feedback circuit at the cost of memory specificity.

  19. Pharmacologic inhibition of phospholipase C in the brain attenuates early memory formation in the honeybee (Apis mellifera L.

    Directory of Open Access Journals (Sweden)

    Shota Suenami

    2018-01-01

    Full Text Available Although the molecular mechanisms involved in learning and memory in insects have been studied intensively, the intracellular signaling mechanisms involved in early memory formation are not fully understood. We previously demonstrated that phospholipase C epsilon (PLCe, whose product is involved in calcium signaling, is almost selectively expressed in the mushroom bodies, a brain structure important for learning and memory in the honeybee. Here, we pharmacologically examined the role of phospholipase C (PLC in learning and memory in the honeybee. First, we identified four genes for PLC subtypes in the honeybee genome database. Quantitative reverse transcription-polymerase chain reaction revealed that, among these four genes, three, including PLCe, were expressed higher in the brain than in sensory organs in worker honeybees, suggesting their main roles in the brain. Edelfosine and neomycin, pan-PLC inhibitors, significantly decreased PLC activities in homogenates of the brain tissues. These drugs injected into the head of foragers significantly attenuated memory acquisition in comparison with the control groups, whereas memory retention was not affected. These findings suggest that PLC in the brain is involved in early memory formation in the honeybee. To our knowledge, this is the first report of a role for PLC in learning and memory in an insect.

  20. Prose Learning for Veterinary Educators: Facilitating Acquisition

    Science.gov (United States)

    Harkness, John E.

    1978-01-01

    A prose text in veterinary medicine can be arranged and supplemented to facilitate efficient and effective acquisition into short-term memory. Methods include: variation in textual format; relating new information to previous knowledge and future goals; providing specific, test-relevant objectives or introductions, describing mnemonic devices; and…

  1. An Exploration of Teachers' Narratives: What Are the Facilitators and Constraints Which Promote or Inhibit "Good" Formative Assessment Practices in Schools?

    Science.gov (United States)

    Sach, Elizabeth

    2015-01-01

    This paper set out to explore teachers' narratives in order to understand some of the facilitators and constraints which promote or inhibit good formative assessment practices in schools. A "responsive interview" approach was used to probe a small sample of lower and middle school teachers' perceptions of formative assessment.…

  2. Neural Correlates of Auditory Processing, Learning and Memory Formation in Songbirds

    Science.gov (United States)

    Pinaud, R.; Terleph, T. A.; Wynne, R. D.; Tremere, L. A.

    Songbirds have emerged as powerful experimental models for the study of auditory processing of complex natural communication signals. Intact hearing is necessary for several behaviors in developing and adult animals including vocal learning, territorial defense, mate selection and individual recognition. These behaviors are thought to require the processing, discrimination and memorization of songs. Although much is known about the brain circuits that participate in sensorimotor (auditory-vocal) integration, especially the ``song-control" system, less is known about the anatomical and functional organization of central auditory pathways. Here we discuss findings associated with a telencephalic auditory area known as the caudomedial nidopallium (NCM). NCM has attracted significant interest as it exhibits functional properties that may support higher order auditory functions such as stimulus discrimination and the formation of auditory memories. NCM neurons are vigorously dr iven by auditory stimuli. Interestingly, these responses are selective to conspecific, relative to heterospecific songs and artificial stimuli. In addition, forms of experience-dependent plasticity occur in NCM and are song-specific. Finally, recent experiments employing high-throughput quantitative proteomics suggest that complex protein regulatory pathways are engaged in NCM as a result of auditory experience. These molecular cascades are likely central to experience-associated plasticity of NCM circuitry and may be part of a network of calcium-driven molecular events that support the formation of auditory memory traces.

  3. System level mechanisms of adaptation, learning, memory formation and evolvability: the role of chaperone and other networks.

    Science.gov (United States)

    Gyurko, David M; Soti, Csaba; Stetak, Attila; Csermely, Peter

    2014-05-01

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

  4. Oseltamivir Prophylaxis Reduces Inflammation and Facilitates Establishment of Cross-Strain Protective T Cell Memory to Influenza Viruses.

    Directory of Open Access Journals (Sweden)

    Nicola L Bird

    Full Text Available CD8(+ T cells directed against conserved viral regions elicit broad immunity against distinct influenza viruses, promote rapid virus elimination and enhanced host recovery. The influenza neuraminidase inhibitor, oseltamivir, is prescribed for therapy and prophylaxis, although it remains unclear how the drug impacts disease severity and establishment of effector and memory CD8(+ T cell immunity. We dissected the effects of oseltamivir on viral replication, inflammation, acute CD8(+ T cell responses and the establishment of immunological CD8(+ T cell memory. In mice, ferrets and humans, the effect of osteltamivir on viral titre was relatively modest. However, prophylactic oseltamivir treatment in mice markedly reduced morbidity, innate responses, inflammation and, ultimately, the magnitude of effector CD8(+ T cell responses. Importantly, functional memory CD8(+ T cells established during the drug-reduced effector phase were capable of mounting robust recall responses. Moreover, influenza-specific memory CD4(+ T cells could be also recalled after the secondary challenge, while the antibody levels were unaffected. This provides evidence that long-term memory T cells can be generated during an oseltamivir-interrupted infection. The anti-inflammatory effect of oseltamivir was verified in H1N1-infected patients. Thus, in the case of an unpredicted influenza pandemic, while prophylactic oseltamivir treatment can reduce disease severity, the capacity to generate memory CD8(+ T cells specific for the newly emerged virus is uncompromised. This could prove especially important for any new influenza pandemic which often occurs in separate waves.

  5. Estradiol replacement enhances fear memory formation, impairs extinction and reduces COMT expression levels in the hippocampus of ovariectomized female mice.

    Science.gov (United States)

    McDermott, Carmel M; Liu, Dan; Ade, Catherine; Schrader, Laura A

    2015-02-01

    Females experience depression, posttraumatic stress disorder (PTSD), and anxiety disorders at approximately twice the rate of males, but the mechanisms underlying this difference remain undefined. The effect of sex hormones on neural substrates presents a possible mechanism. We investigated the effect of ovariectomy at two ages, before puberty and in adulthood, and 17β-estradiol (E2) replacement administered chronically in drinking water on anxiety level, fear memory formation, and extinction. Based on previous studies, we hypothesized that estradiol replacement would impair fear memory formation and enhance extinction rate. Females, age 4 weeks and 10 weeks, were divided randomly into 4 groups; sham surgery, OVX, OVX+low E2 (200nM), and OVX+high E2 (1000nM). Chronic treatment with high levels of E2 significantly increased anxiety levels measured in the elevated plus maze. In both age groups, high levels of E2 significantly increased contextual fear memory but had no effect on cued fear memory. In addition, high E2 decreased the rate of extinction in both ages. Finally, catechol-O-methyltransferase (COMT) is important for regulation of catecholamine levels, which play a role in fear memory formation and extinction. COMT expression in the hippocampus was significantly reduced by high E2 replacement, implying increased catecholamine levels in the hippocampus of high E2 mice. These results suggest that estradiol enhanced fear memory formation, and inhibited fear memory extinction, possibly stabilizing the fear memory in female mice. This study has implications for a neurobiological mechanism for PTSD and anxiety disorders. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Context memory in korsakoff and unilateral hippocamectomy patients

    NARCIS (Netherlands)

    Tielemans, N.S.; Hendriks, M.P.H.; Talamini, L.M.; Wester, A.K.; Meeter, M.; Kessels, R.P.

    2012-01-01

    Item-context binding is crucial for successful episodic memory formation, and binding deficits have been suggested to underlie episodic-memory deficits. Here, our research investigated the facilitation of cued recall and recognition memory by contextual cues in 20 patients with Korsakoff's amnesia,

  7. Emotional face expression modulates occipital-frontal effective connectivity during memory formation in a bottom-up fashion

    Directory of Open Access Journals (Sweden)

    Daiming eXiu

    2015-04-01

    Full Text Available This study investigated the role of bottom-up and top-down neural mechanisms in the processing of emotional face expression during memory formation. Functional brain imaging data was acquired during incidental learning of positive (‘happy’, neutral and negative (‘angry’ or ‘fearful’ faces. Dynamic Causal Modeling (DCM was applied on the fMRI data to characterize effective connectivity within a brain network involving face perception (inferior occipital gyrus and fusiform gyrus and successful memory formation related areas (hippocampus, superior parietal lobule, amygdala and orbitofrontal cortex. The bottom-up models assumed processing of emotional face expression along feed forward pathways to the orbitofrontal cortex. The top-down models assumed that the orbitofrontal cortex processed emotional valence and mediated connections to the hippocampus. A subsequent recognition memory test showed an effect of negative emotion on the response bias, but not on memory performance. Our DCM findings showed that the bottom-up model family of effective connectivity best explained the data across all subjects and specified that emotion affected most bottom-up connections to the orbitofrontal cortex, especially from the occipital visual cortex and superior parietal lobule. Of those pathways to the orbitofrontal cortex the connection from the inferior occipital gyrus correlated with memory performance independently of valence. We suggest that bottom-up neural mechanisms support effects of emotional face expression and memory formation in a parallel and partially overlapping fashion.

  8. The Small GTPase Rac1 Contributes to Extinction of Aversive Memories of Drug Withdrawal by Facilitating GABAA Receptor Endocytosis in the vmPFC.

    Science.gov (United States)

    Wang, Weisheng; Ju, Yun-Yue; Zhou, Qi-Xin; Tang, Jian-Xin; Li, Meng; Zhang, Lei; Kang, Shuo; Chen, Zhong-Guo; Wang, Yu-Jun; Ji, Hui; Ding, Yu-Qiang; Xu, Lin; Liu, Jing-Gen

    2017-07-26

    Extinction of aversive memories has been a major concern in neuropsychiatric disorders, such as anxiety disorders and drug addiction. However, the mechanisms underlying extinction of aversive memories are not fully understood. Here, we report that extinction of conditioned place aversion (CPA) to naloxone-precipitated opiate withdrawal in male rats activates Rho GTPase Rac1 in the ventromedial prefrontal cortex (vmPFC) in a BDNF-dependent manner, which determines GABA A receptor (GABA A R) endocytosis via triggering synaptic translocation of activity-regulated cytoskeleton-associated protein (Arc) through facilitating actin polymerization. Active Rac1 is essential and sufficient for GABA A R endocytosis and CPA extinction. Knockdown of Rac1 expression within the vmPFC of rats using Rac1-shRNA suppressed GABA A R endocytosis and CPA extinction, whereas expression of a constitutively active form of Rac1 accelerated GABA A R endocytosis and CPA extinction. The crucial role of GABA A R endocytosis in the LTP induction and CPA extinction is evinced by the findings that blockade of GABA A R endocytosis by a dynamin function-blocking peptide (Myr-P4) abolishes LTP induction and CPA extinction. Thus, the present study provides first evidence that Rac1-dependent GABA A R endocytosis plays a crucial role in extinction of aversive memories and reveals the sequence of molecular events that contribute to learning experience modulation of synaptic GABA A R endocytosis. SIGNIFICANCE STATEMENT This study reveals that Rac1-dependent GABA A R endocytosis plays a crucial role in extinction of aversive memories associated with drug withdrawal and identifies Arc as a downstream effector of Rac1 regulations of synaptic plasticity as well as learning and memory, thereby suggesting therapeutic targets to promote extinction of the unwanted memories. Copyright © 2017 the authors 0270-6474/17/377096-15$15.00/0.

  9. The Role of Lactate-Mediated Metabolic Coupling between Astrocytes and Neurons in Long-Term Memory Formation

    Science.gov (United States)

    Steinman, Michael Q.; Gao, Virginia; Alberini, Cristina M.

    2016-01-01

    Long-term memory formation, the ability to retain information over time about an experience, is a complex function that affects multiple behaviors, and is an integral part of an individual’s identity. In the last 50 years many scientists have focused their work on understanding the biological mechanisms underlying memory formation and processing. Molecular studies over the last three decades have mostly investigated, or given attention to, neuronal mechanisms. However, the brain is composed of different cell types that, by concerted actions, cooperate to mediate brain functions. Here, we consider some new insights that emerged from recent studies implicating astrocytic glycogen and glucose metabolisms, and particularly their coupling to neuronal functions via lactate, as an essential mechanism for long-term memory formation. PMID:26973477

  10. Autonomy in action: linking the act of looking to memory formation in infancy via dynamic neural fields.

    Science.gov (United States)

    Perone, Sammy; Spencer, John P

    2013-01-01

    Looking is a fundamental exploratory behavior by which infants acquire knowledge about the world. In theories of infant habituation, however, looking as an exploratory behavior has been deemphasized relative to the reliable nature with which looking indexes active cognitive processing. We present a new theory that connects looking to the dynamics of memory formation and formally implement this theory in a Dynamic Neural Field model that learns autonomously as it actively looks and looks away from a stimulus. We situate this model in a habituation task and illustrate the mechanisms by which looking, encoding, working memory formation, and long-term memory formation give rise to habituation across multiple stimulus and task contexts. We also illustrate how the act of looking and the temporal dynamics of learning affect each other. Finally, we test a new hypothesis about the sources of developmental differences in looking. Copyright © 2012 Cognitive Science Society, Inc.

  11. The role of lactate-mediated metabolic coupling between astrocytes and neurons in long-term memory formation

    Directory of Open Access Journals (Sweden)

    Michael eSteinman

    2016-03-01

    Full Text Available Long-term memory formation, the ability to retain information over time about an experience, is a complex function that affects multiple behaviors, and is an integral part of an individual’s identity. In the last 50 years many scientists have focused their work on understanding the biological mechanisms underlying memory formation and processing. Molecular studies over the last three decades have mostly investigated, or given attention to, neuronal mechanisms. However, the brain is composed of different cell types that, by concerted actions, cooperate to mediate brain functions. Here we consider some new insights that emerged from recent studies implicating astrocytic glycogen and glucose metabolisms, and particularly their coupling to neuronal functions via lactate, as an essential mechanism for long-term memory formation.

  12. Activation of GABA(A) receptors in the accessory olfactory bulb does not prevent the formation of an olfactory memory in mice.

    Science.gov (United States)

    Otsuka, T; Hashida, M; Oka, T; Kaba, H

    2001-07-01

    When female mice are mated, they form a memory to the pheromonal signal of their male partner. The neural mechanisms underlying this memory involve changes at the reciprocal dendrodendritic synapses between glutamatergic mitral cells and gamma-aminobutyric acid (GABA)-ergic granule cells in the accessory olfactory bulb (AOB). Blockade of GABA(A) receptors in the AOB leads to the formation of an olfactory memory. In an attempt to disrupt memory formation at mating, we used local infusions of the GABA(A) receptor agonist muscimol into the AOB during the critical period for memory formation. Muscimol across a wide range of doses (1-1000 pmol) did not prevent memory formation. The resistance of this memory to GABA(A) receptor activation may reflect the complexity of synaptic microcircuits in the AOB.

  13. Understanding adult neurogenesis beyond its role in learning and memory formation

    Directory of Open Access Journals (Sweden)

    Ab Latif Wani

    2017-04-01

    Full Text Available There has been a shift in the understanding of brain, neurons, and their functional role over the last two decades. Earlier it was believed that the brain was a static organ and was not subject to any change throughout life. An understanding was developed later that brain reorganizes its structure by a specific property called neuroplasticity. Recent research shows that the brain generates new neurons even in the adult stage, and this process is called adult neurogenesis. Although researchers still not have all the answers about the newborn neurons, and why and how they are generated, and what is their role, some have highlighted the importance of these in learning and memory formation, and even in memories of fear and spatial navigation. A wide range of environmental experience influences the generation of newborn neurons and their functional variability. There are questions about how different environmental experiences cause the differences in the generation of new neurons. Recently the field of optogenetics attempted to answer the questions on adult neurogenesis. However there are still questions about adult neurogenesis which needs a more naturalistic approach, for their better understanding.

  14. Long-term potentiation and olfactory memory formation in the carp (Cyprinus carpio L.) olfactory bulb.

    Science.gov (United States)

    Satou, M; Anzai, S; Huruno, M

    2005-05-01

    Long-term potentiation of synaptic transmission is considered to be an elementary process underlying the cellular mechanism of memory formation. In the present study we aimed to examine whether or not the dendrodendritic mitral-to-granule cell synapses in the carp olfactory bulb show plastic changes after their repeated activation. It was found that: (1) the dendrodendritic mitral-to-granule cell synapses showed three types of plasticity after tetanic electrical stimulation applied to the olfactory tract-long-term potentiation (potentiation lasting >1 h), short-term potentiation (potentiation lasting 1 h) of the odor-evoked bulbar response accompanied the electrically-induced LTP, and; (4) repeated olfactory stimulation enhanced dendrodendritic mitral-to-granule cell transmission. Based on these results, it was proposed that long-term potentiation (as well as olfactory memory) occurs at the dendrodendritic mitral-to-granule cell synapses after strong and long-lasting depolarization of granule cells, which follows repeated and simultaneous synaptic activation of both the peripheral and deep dendrites (or somata).

  15. Long-lasting and transgenerational effects of an environmental enrichment on memory formation.

    Science.gov (United States)

    Arai, Junko A; Feig, Larry A

    2011-04-25

    It has long been believed that genetically determined, but not environmentally acquired, phenotypes can be inherited. However, a large number of recent studies have reported that phenotypes acquired from an animal's environment can be transmitted to the next generation. Moreover, epidemiology studies have hinted that a similar phenomenon occurs in humans. This type of inheritance does not involve gene mutations that change DNA sequence. Instead, it is thought that epigenetic changes in chromatin, such as DNA methylation and histone modification, occur. In this review, we will focus on one exciting new example of this phenomenon, transfer across generations of enhanced synaptic plasticity and memory formation induced by exposure to an "enriched" environment. Copyright © 2010 Elsevier Inc. All rights reserved.

  16. Vegetation pattern formation in semiarid systems induced by long-range competition in the absence of facilitation mechanisms.

    Science.gov (United States)

    Martinez-Garcia, Ricardo; Calabrese, Justin M.; Hernandez-Garcia, Emilio; Lopez, Cristobal

    2014-05-01

    and its range. When the finite range of the competitive interaction is considered used kernel functions with a finite range, whose Fourier transform may have negative values, patterns emerge in the system. This is a rather general condition if we consider the finite length of the roots responsible of long-range competition for water in plant ecosystems.Therefore, our findings support the notion that, under fairly broad conditions, only competition is required for patterns to occur and suggest that the role of short-range facilitation mechanisms may not be as fundamental to pattern formation as has previously been thought. REFERENCES: C.A. Klausmeier, Science, 284, 1826-1828 (1999). F. Borgogno, P. D'Odorico, F. Laio and L. Ridolfi, Reviews of Geophysics, 4, RG1005 (2009). R. Martinez-Garcia, J.M. Calabrese, and C. Lopez, Journal of Theoretical Biology, 333, 156-165 (2013). R. Martinez-Garcia, J. M. Calabrese, E. Hernandez-Garcia, and C. Lopez, Geophysical Research Letters, 40, 6143-6147,(2013).

  17. Analysis of Memory Formation during General Anesthesia (Propofol/Remifentanil) for Elective Surgery Using the Process-dissociation Procedure.

    Science.gov (United States)

    Hadzidiakos, Daniel; Horn, Nadja; Degener, Roland; Buchner, Axel; Rehberg, Benno

    2009-08-01

    There have been reports of memory formation during general anesthesia. The process-dissociation procedure has been used to determine if these are controlled (explicit/conscious) or automatic (implicit/unconscious) memories. This study used the process-dissociation procedure with the original measurement model and one which corrected for guessing to determine if more accurate results were obtained in this setting. A total of 160 patients scheduled for elective surgery were enrolled. Memory for words presented during propofol and remifentanil general anesthesia was tested postoperatively by using a word-stem completion task in a process-dissociation procedure. To assign possible memory effects to different levels of anesthetic depth, the authors measured depth of anesthesia using the BIS XP monitor (Aspect Medical Systems, Norwood, MA). Word-stem completion performance showed no evidence of memory for intraoperatively presented words. Nevertheless, an evaluation of these data using the original measurement model for process-dissociation data suggested an evidence of controlled (C = 0.05; 95% confidence interval [CI] 0.02-0.08) and automatic (A = 0.11; 95% CI 0.09-0.12) memory processes (P memory processes was obtained. The authors report and discuss parallel findings for published data sets that were generated by using the process-dissociation procedure. Patients had no memories for auditory information presented during propofol/remifentanil anesthesia after midazolam premedication. The use of the process-dissociation procedure with the original measurement model erroneously detected memories, whereas the extended model, corrected for guessing, correctly revealed no memory.

  18. CREB expression in the brains of two closely related parasitic wasp species that differ in long-term memory formation

    NARCIS (Netherlands)

    Van den Berg, M.; Verbaarschot, P.; Hontelez, S.; Vet, L.E.M.; Dicke, M.; Smid, H.M.

    2010-01-01

    The cAMP/PKA signalling pathway and transcription factor cAMP response element-binding protein (CREB) play key roles in long-term memory (LTM) formation. We used two closely related parasitic wasp species, Cotesia glomerata and Cotesia rubecula, which were previously shown to be different in LTM

  19. The participation of NMDA receptors, PKC, and MAPK in the formation of memory following operant conditioning in Lymnaea

    Directory of Open Access Journals (Sweden)

    Rosenegger David

    2010-08-01

    Full Text Available Abstract Background Memory is the ability to store, retain, and later retrieve information that has been learned. Intermediate term memory (ITM that persists for up to 3 h requires new protein synthesis. Long term memory (LTM that persists for at least 24 h requires: DNA transcription, RNA translation, and the trafficking of newly synthesized proteins. It has been shown in a number of different model systems that NMDA receptors, protein kinase C (PKC and mitogen activated protein kinase (MAPK are all involved in the memory formation process. Results Here we show that snails trained in control conditions are capable of forming, depending on the training procedure used, either ITM or LTM. However, blockage of NMDA receptors (MK 801, inhibition of PKC (GF109203X hydrochloride and MAPK activity (UO126 prevent the formation of both ITM and LTM. Conclusions The injection of either U0126 or GF109203X, which inhibit MAPK and PKC activity respectively, 1 hour prior to training results in the inhibition of both ITM and LTM formation. We further found that NMDA receptor activity was necessary in order for both ITM and LTM formation.

  20. The Ubiquitin-Specific Protease 14 (USP14) Is a Critical Regulator of Long-Term Memory Formation

    Science.gov (United States)

    Jarome, Timothy J.; Kwapis, Janine L.; Hallengren, Jada J.; Wilson, Scott M.; Helmstetter, Fred J.

    2014-01-01

    Numerous studies have suggested a role for ubiquitin-proteasome-mediated protein degradation in learning-dependent synaptic plasticity; however, very little is known about how protein degradation is regulated at the level of the proteasome during memory formation. The ubiquitin-specific protease 14 (USP14) is a proteasomal deubiquitinating enzyme…

  1. The Calmodulin-Binding Transcription Activator CAMTA1 Is Required for Long-Term Memory Formation in Mice

    Science.gov (United States)

    Bas-Orth, Carlos; Tan, Yan-Wei; Oliveira, Ana M. M.; Bengtson, C. Peter; Bading, Hilmar

    2016-01-01

    The formation of long-term memory requires signaling from the synapse to the nucleus to mediate neuronal activity-dependent gene transcription. Synapse-to-nucleus communication is initiated by influx of calcium ions through synaptic NMDA receptors and/or L-type voltage-gated calcium channels and involves the activation of transcription factors by…

  2. Inhibition of Different Histone Acetyltransferases (HATs) Uncovers Transcription-Dependent and -Independent Acetylation-Mediated Mechanisms in Memory Formation

    Science.gov (United States)

    Merschbaecher, Katja; Hatko, Lucyna; Folz, Jennifer; Mueller, Uli

    2016-01-01

    Acetylation of histones changes the efficiency of the transcription processes and thus contributes to the formation of long-term memory (LTM). In our comparative study, we used two inhibitors to characterize the contribution of different histone acetyl transferases (HATs) to appetitive associative learning in the honeybee. For one we applied…

  3. NMDA Receptor- and ERK-Dependent Histone Methylation Changes in the Lateral Amygdala Bidirectionally Regulate Fear Memory Formation

    Science.gov (United States)

    Gupta-Agarwal, Swati; Jarome, Timothy J.; Fernandez, Jordan; Lubin, Farah D.

    2014-01-01

    It is well established that fear memory formation requires de novo gene transcription in the amygdala. We provide evidence that epigenetic mechanisms in the form of histone lysine methylation in the lateral amygdala (LA) are regulated by NMDA receptor (NMDAR) signaling and involved in gene transcription changes necessary for fear memory…

  4. Technetium migration in Boom Clay - Assessing the role of colloid-facilitated transport in a deep clay formation

    International Nuclear Information System (INIS)

    Bruggeman, C.; Martens, E.; Maes, N.; Jacops, E.; Van Gompel, M.; Van Ravestyn, L.

    2010-01-01

    independent study on the migration of natural organic matter was used to extract migration parameters. This independent study relied on both lab-scale and in situ large-scale migration experiments with 14 C-labelled NOM which were performed over a period of 15 years. A classic diffusion-advection equation, including a colloid filtration term and/or non-linear sorption, simulated the experimental data quite well and could also account for the anisotropy of the Boom Clay formation. By using information from independent experiments on processes that were assumed to occur upon transport of Tc through the Boom Clay formation, the degree of freedom of the model was seriously constrained. All parameters used in the reactive transport model (Tc solubility, complexation with inorganic ligands, stability constant for the 'colloid-colloid' interaction process, solid-solution distribution coefficient of aqueous inorganic Tc species) were either taken from established thermodynamic data sources, or from published data of batch experiments. Only the first-order kinetic rate that accounted for slow decoupling of the Tc colloid and the organic matter colloids was fitted. An accurate model simulation could be obtained both for the Tc concentration in the outflowing solution, and the Tc tracer profile across the clay cores used in the setup. The good accuracy between the reactive transport model, batch experimental data and the experimental percolation data shows that the conceptual model is strong enough to handle different types of experimental setups, and allows to make interpolations for different geochemical conditions. Moreover, the model was adapted to make predictions of Tc migration as a NOM-associated colloid over the entire height of the overlying formation. Based on these predictions, we are now able to assess the potential for colloid-facilitated transport of radionuclides by dissolved NOM in Boom Clay. (authors)

  5. Oseltamivir Prophylaxis Reduces Inflammation and Facilitates Establishment of Cross-Strain Protective T Cell Memory to Influenza Viruses

    OpenAIRE

    Bird, Nicola L.; Olson, Matthew R.; Hurt, Aeron C.; Oshansky, Christine M.; Oh, Ding Yuan; Reading, Patrick C.; Chua, Brendon Y.; Sun, Yilun; Tang, Li; Handel, Andreas; Jackson, David C.; Turner, Stephen J.; Thomas, Paul G.; Kedzierska, Katherine

    2015-01-01

    CD8(+) T cells directed against conserved viral regions elicit broad immunity against distinct influenza viruses, promote rapid virus elimination and enhanced host recovery. The influenza neuraminidase inhibitor, oseltamivir, is prescribed for therapy and prophylaxis, although it remains unclear how the drug impacts disease severity and establishment of effector and memory CD8(+) T cell immunity. We dissected the effects of oseltamivir on viral replication, inflammation, acute CD8(+) T cell r...

  6. Remembering what was said and done: The activation and facilitation of memory for gesture as a consequence of retrieval.

    Science.gov (United States)

    Overoye, Acacia L; Storm, Benjamin C

    2018-04-26

    The gestures that occur alongside speech provide listeners with cues that both improve and alter memory for speech. The present research investigated the interplay of gesture and speech by examining the influence of retrieval on memory for gesture. In three experiments, participants watched video clips of an actor speaking a series of statements with or without gesture before being asked to retrieve the speech portions of half of those statements. Participants were then tested on their ability to recall whether the actor had gestured during each statement and, if so, to recall the nature of the gesture that was produced. Results indicated that attempting to retrieve the speech portion of the statements enhanced participants' ability to remember the gesture portion of the statements. This result was only observed, however, for representational gestures when the speech and gesture components were meaningfully related (Experiments 1 & 2). It was not observed for beat gestures or nonsense gestures (Experiments 2 & 3). These results are consistent with the idea that gestures can be coactivated during the retrieval of speech and that such coactivation is due to the integrated representation of speech and gesture in memory. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  7. Molecular and Neuronal Plasticity Mechanisms in the Amygdala-Prefrontal Cortical Circuit: Implications for Opiate Addiction Memory Formation

    Directory of Open Access Journals (Sweden)

    Laura G Rosen

    2015-11-01

    Full Text Available The persistence of associative memories linked to the rewarding properties of drugs of abuse is a core underlying feature of the addiction process. Opiate class drugs in particular, possess potent euphorigenic effects which, when linked to environmental cues, can produce drug-related ‘trigger’ memories that may persist for lengthy periods of time, even during abstinence, in both humans and other animals. Furthermore, the transitional switch from the drug-naïve, non-dependent state to states of dependence and withdrawal, represents a critical boundary between distinct neuronal and molecular substrates associated with opiate-reward memory formation. Identifying the functional molecular and neuronal mechanisms related to the acquisition, consolidation, recall and extinction phases of opiate-related reward memories is critical for understanding, and potentially reversing, addiction-related memory plasticity characteristic of compulsive drug-seeking behaviors. The mammalian prefrontal cortex (PFC and basolateral nucleus of the amygdala (BLA share important functional and anatomical connections that are involved importantly in the processing of associative memories linked to drug reward. In addition, both regions share interconnections with the mesolimbic pathway’s ventral tegmental area (VTA and nucleus accumbens (NAc and can modulate dopamine (DA transmission and neuronal activity associated with drug-related DAergic signaling dynamics. In this review, we will summarize research from both human and animal modelling studies highlighting the importance of neuronal and molecular plasticity mechanisms within this circuitry during critical phases of opiate addiction-related learning and memory processing. Specifically, we will focus on two molecular signaling pathways known to be involved in both drug-related neuroadaptations and in memory-related plasticity mechanisms; the extracellular-signal-regulated kinase system (ERK and the Ca2+/calmodulin

  8. Formation of titanium oxide coatings on NiTi shape memory alloys by selective oxidation

    International Nuclear Information System (INIS)

    Pohl, M.; Glogowski, T.; Kuehn, S.; Hessing, C.; Unterumsberger, F.

    2008-01-01

    Materials used for medical devices that are in contact with human tissue must have good corrosion resistance and biocompatibility. NiTi shape memory alloys (SMAs) are often used in medical applications due to their special functional and mechanical properties (shape memory effect, pseudo elasticity). Because of the high Ni content in nearly stoichiometric NiTi SMAs, the possibility of Ni being released needs to be considered as Ni may cause problems in the human body. SMAs exhibit a high intrinsic corrosion resistance because of the thermodynamic stability of Ni (thermodynamic reason) and the low degree of disorder in a thin protective TiO 2 -layer (kinetic reason). While therefore there is no need to be concerned too much about a normal corrosive attack in the human body, it has to be kept in mind that in medical applications, these materials represent one part of a tribological system where wear processes need to be considered. The formation of a uniform TiO 2 -layer can be beneficial in this respect. The selective oxidation of Ti to TiO 2 on the surface is a promising method to decrease the Ni release significantly. This can be achieved by controlling the partial pressure of oxygen during a controlled oxidation process. The atmosphere must be adjusted so that TiO 2 is stable while NiO cannot yet form. The result of a selective oxidation is a TiO 2 -layer that has an excellent degree of purity and represents a safe barrier against Ni emission

  9. Central Nervous Insulin Signaling in Sleep-Associated Memory Formation and Neuroendocrine Regulation

    OpenAIRE

    Feld, Gordon B; Wilhem, Ines; Benedict, Christian; Rüdel, Benjamin; Klameth, Corinna; Born, Jan; Hallschmid, Manfred

    2016-01-01

    The neurochemical underpinnings of sleep's contribution to the establishment and maintenance of memory traces are largely unexplored. Considering that intranasal insulin administration to the CNS improves memory functions in healthy and memory-impaired humans, we tested whether brain insulin signaling and sleep interact to enhance memory consolidation in healthy participants. We investigated the effect of intranasal insulin on sleep-associated neurophysiological and neuroendocrine parameters ...

  10. β-Adrenergic Receptors Regulate the Acquisition and Consolidation Phases of Aversive Memory Formation Through Distinct, Temporally Regulated Signaling Pathways.

    Science.gov (United States)

    Schiff, Hillary C; Johansen, Joshua P; Hou, Mian; Bush, David E A; Smith, Emily K; Klein, JoAnna E; LeDoux, Joseph E; Sears, Robert M

    2017-03-01

    Memory formation requires the temporal coordination of molecular events and cellular processes following a learned event. During Pavlovian threat (fear) conditioning (PTC), sensory and neuromodulatory inputs converge on post-synaptic neurons within the lateral nucleus of the amygdala (LA). By activating an intracellular cascade of signaling molecules, these G-protein-coupled neuromodulatory receptors are capable of recruiting a diverse profile of plasticity-related proteins. Here we report that norepinephrine, through its actions on β-adrenergic receptors (βARs), modulates aversive memory formation following PTC through two molecularly and temporally distinct signaling mechanisms. Specifically, using behavioral pharmacology and biochemistry in adult rats, we determined that βAR activity during, but not after PTC training initiates the activation of two plasticity-related targets: AMPA receptors (AMPARs) for memory acquisition and short-term memory and extracellular regulated kinase (ERK) for consolidating the learned association into a long-term memory. These findings reveal that βAR activity during, but not following PTC sets in motion cascading molecular events for the acquisition (AMPARs) and subsequent consolidation (ERK) of learned associations.

  11. Barriers to and Facilitators of Walking and Bicycling to School: Formative Results from the Non-Motorized Travel Study

    Science.gov (United States)

    Ahlport, Kathryn N.; Linnan, Laura; Vaughn, Amber; Evenson, Kelly R.; Ward, Dianne S.

    2008-01-01

    Barriers to and facilitators of walking and bicycling to school were explored through 12 focus groups made up of fourth- and fifth-grade students and their parents who lived near their respective schools. The barriers and facilitators reported by parents and children generally fell into one of three categories: intrapersonal and interpersonal…

  12. Implications of psychosocial stress on memory formation in a typical male versus female student sample.

    NARCIS (Netherlands)

    Cornelisse, S.; van Stegeren, A.H.; Joëls, M.

    2011-01-01

    Stress is known to differentially modulate memory function. Memory can be impaired or strengthened by stress, depending on e.g. the memory type and phase under study, the emotional value of the learned information and the sex of the subjects. Here, we addressed the latter and investigated the impact

  13. Sensory and short-term memory formations observed in a Ag2S gap-type atomic switch

    Science.gov (United States)

    Ohno, Takeo; Hasegawa, Tsuyoshi; Nayak, Alpana; Tsuruoka, Tohru; Gimzewski, James K.; Aono, Masakazu

    2011-11-01

    Memorization caused by the change in conductance in a Ag2S gap-type atomic switch was investigated as a function of the amplitude and width of input voltage pulses (Vin). The conductance changed little for the first few Vin, but the information of the input was stored as a redistribution of Ag-ions in the Ag2S, indicating the formation of sensory memory. After a certain number of Vin, the conductance increased abruptly followed by a gradual decrease, indicating the formation of short-term memory (STM). We found that the probability of STM formation depends strongly on the amplitude and width of Vin, which resembles the learning behavior of the human brain.

  14. The relationship between level of processing and hippocampal-cortical functional connectivity during episodic memory formation in humans.

    Science.gov (United States)

    Schott, Björn H; Wüstenberg, Torsten; Wimber, Maria; Fenker, Daniela B; Zierhut, Kathrin C; Seidenbecher, Constanze I; Heinze, Hans-Jochen; Walter, Henrik; Düzel, Emrah; Richardson-Klavehn, Alan

    2013-02-01

    New episodic memory traces represent a record of the ongoing neocortical processing engaged during memory formation (encoding). Thus, during encoding, deep (semantic) processing typically establishes more distinctive and retrievable memory traces than does shallow (perceptual) processing, as assessed by later episodic memory tests. By contrast, the hippocampus appears to play a processing-independent role in encoding, because hippocampal lesions impair encoding regardless of level of processing. Here, we clarified the neural relationship between processing and encoding by examining hippocampal-cortical connectivity during deep and shallow encoding. Participants studied words during functional magnetic resonance imaging and freely recalled these words after distraction. Deep study processing led to better recall than shallow study processing. For both levels of processing, successful encoding elicited activations of bilateral hippocampus and left prefrontal cortex, and increased functional connectivity between left hippocampus and bilateral medial prefrontal, cingulate and extrastriate cortices. Successful encoding during deep processing was additionally associated with increased functional connectivity between left hippocampus and bilateral ventrolateral prefrontal cortex and right temporoparietal junction. In the shallow encoding condition, on the other hand, pronounced functional connectivity increases were observed between the right hippocampus and the frontoparietal attention network activated during shallow study processing. Our results further specify how the hippocampus coordinates recording of ongoing neocortical activity into long-term memory, and begin to provide a neural explanation for the typical advantage of deep over shallow study processing for later episodic memory. Copyright © 2011 Wiley Periodicals, Inc.

  15. Memory

    OpenAIRE

    Wager, Nadia

    2017-01-01

    This chapter will explore a response to traumatic victimisation which has divided the opinions of psychologists at an exponential rate. We will be examining amnesia for memories of childhood sexual abuse and the potential to recover these memories in adulthood. Whilst this phenomenon is generally accepted in clinical circles, it is seen as highly contentious amongst research psychologists, particularly experimental cognitive psychologists. The chapter will begin with a real case study of a wo...

  16. Repetition suppression and repetition enhancement underlie auditory memory-trace formation in the human brain: an MEG study.

    Science.gov (United States)

    Recasens, Marc; Leung, Sumie; Grimm, Sabine; Nowak, Rafal; Escera, Carles

    2015-03-01

    The formation of echoic memory traces has traditionally been inferred from the enhanced responses to its deviations. The mismatch negativity (MMN), an auditory event-related potential (ERP) elicited between 100 and 250ms after sound deviation is an indirect index of regularity encoding that reflects a memory-based comparison process. Recently, repetition positivity (RP) has been described as a candidate ERP correlate of direct memory trace formation. RP consists of repetition suppression and enhancement effects occurring in different auditory components between 50 and 250ms after sound onset. However, the neuronal generators engaged in the encoding of repeated stimulus features have received little interest. This study intends to investigate the neuronal sources underlying the formation and strengthening of new memory traces by employing a roving-standard paradigm, where trains of different frequencies and different lengths are presented randomly. Source generators of repetition enhanced (RE) and suppressed (RS) activity were modeled using magnetoencephalography (MEG) in healthy subjects. Our results show that, in line with RP findings, N1m (~95-150ms) activity is suppressed with stimulus repetition. In addition, we observed the emergence of a sustained field (~230-270ms) that showed RE. Source analysis revealed neuronal generators of RS and RE located in both auditory and non-auditory areas, like the medial parietal cortex and frontal areas. The different timing and location of neural generators involved in RS and RE points to the existence of functionally separated mechanisms devoted to acoustic memory-trace formation in different auditory processing stages of the human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Differentially expressed genes linked to natural variation in long-term memory formation in Cotesia parasitic wasps

    Directory of Open Access Journals (Sweden)

    Joke J. F. A. Van Vugt

    2015-09-01

    Full Text Available Even though learning and memory are universal traits in the Animal Kingdom, closely related species reveal substantial variation in learning rate and memory dynamics. To determine the genetic background of this natural variation, we studied two congeneric parasitic wasp species, Cotesia glomerata and C. rubecula, which lay their eggs in caterpillars of the large and small cabbage white butterfly. A successful egg laying event serves as an unconditioned stimulus in a classical conditioning paradigm, where plant odors become associated to the encounter of a suitable host caterpillar. Depending on the host species, the number of conditioning trials and the parasitic wasp species, three different types of transcription-dependent long-term memory (LTM and one type of transcription-independent, anesthesia-resistant memory (ARM can be distinguished. To identify transcripts underlying these differences in memory formation, we isolated mRNA from parasitic wasp heads at three different time points between induction and consolidation of each of the four memory types, and for each sample three biological replicates, where after strand-specific paired-end 100 bp deep sequencing. Transcriptomes were assembled de novo and differential expression was determined for each memory type and time point after conditioning, compared to unconditioned wasps. Most differentially expressed (DE genes and antisense transcripts were only DE in one of the LTM types. Among the DE genes that were DE in two or more LTM types, were many protein kinases and phosphatases, small GTPases, receptors and ion channels. Some genes were DE in opposing directions between any of the LTM memory types and ARM, suggesting that ARM in Cotesia requires the transcription of genes inhibiting LTM or vice versa. We discuss our findings in the context of neuronal functioning, including RNA splicing and transport, epigenetic regulation, neurotransmitter/peptide synthesis and antisense transcription. In

  18. Individual language experience modulates rapid formation of cortical memory circuits for novel words

    Science.gov (United States)

    Kimppa, Lilli; Kujala, Teija; Shtyrov, Yury

    2016-01-01

    Mastering multiple languages is an increasingly important ability in the modern world; furthermore, multilingualism may affect human learning abilities. Here, we test how the brain’s capacity to rapidly form new representations for spoken words is affected by prior individual experience in non-native language acquisition. Formation of new word memory traces is reflected in a neurophysiological response increase during a short exposure to novel lexicon. Therefore, we recorded changes in electrophysiological responses to phonologically native and non-native novel word-forms during a perceptual learning session, in which novel stimuli were repetitively presented to healthy adults in either ignore or attend conditions. We found that larger number of previously acquired languages and earlier average age of acquisition (AoA) predicted greater response increase to novel non-native word-forms. This suggests that early and extensive language experience is associated with greater neural flexibility for acquiring novel words with unfamiliar phonology. Conversely, later AoA was associated with a stronger response increase for phonologically native novel word-forms, indicating better tuning of neural linguistic circuits to native phonology. The results suggest that individual language experience has a strong effect on the neural mechanisms of word learning, and that it interacts with the phonological familiarity of the novel lexicon. PMID:27444206

  19. Nanoscale indent formation in shape memory polymers using a heated probe tip

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801 (United States); Wornyo, E [School of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Gall, K [Department of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332 (United States); King, W P [Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801 (United States)

    2007-07-18

    This paper presents experimental investigation of nanoscale indentation formation in shape memory polymers. The polymers were synthesized by photopolymerizing a tert-butyl acrylate (tBA) monomer with a poly(ethylene glycol dimethacrylate) (PEGDMA) crosslinker. The concentration and the molecular weight of the crosslinker were varied to produce five polymers with tailored properties. Nanoscale indentations were formed on the polymer surfaces by using a heated atomic force microscope (AFM) cantilever at various temperatures near or above the glass transition (between 84 and 215 deg. C) and a range of heating durations from 100 {mu}s to 8 ms. The images of the indents were obtained with the same probe tip at room temperature. The contact pressure, a measure of transient hardness, was derived from the indentation height data as a function of time and temperature for different polymers. With increasing crosslinker molecular weight and decreasing crosslinker concentration, the contact pressures decreased at a fixed maximum load due to increased crosslink spacing in the polymer system. The results provide insight into the nanoscale response of these novel materials.

  20. Temporal course of gene expression during motor memory formation in primary motor cortex of rats.

    Science.gov (United States)

    Hertler, B; Buitrago, M M; Luft, A R; Hosp, J A

    2016-12-01

    Motor learning is associated with plastic reorganization of neural networks in primary motor cortex (M1) that depends on changes in gene expression. Here, we investigate the temporal profile of these changes during motor memory formation in response to a skilled reaching task in rats. mRNA-levels were measured 1h, 7h and 24h after the end of a training session using microarray technique. To assure learning specificity, trained animals were compared to a control group. In response to motor learning, genes are sequentially regulated with high time-point specificity and a shift from initial suppression to later activation. The majority of regulated genes can be linked to learning-related plasticity. In the gene-expression cascade following motor learning, three different steps can be defined: (1) an initial suppression of genes influencing gene transcription. (2) Expression of genes that support translation of mRNA in defined compartments. (3) Expression of genes that immediately mediates plastic changes. Gene expression peaks after 24h - this is a much slower time-course when compared to hippocampus-dependent learning, where peaks of gene-expression can be observed 6-12h after training ended. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Semantic processes leading to true and false memory formation in schizophrenia.

    Science.gov (United States)

    Paz-Alonso, Pedro M; Ghetti, Simona; Ramsay, Ian; Solomon, Marjorie; Yoon, Jong; Carter, Cameron S; Ragland, J Daniel

    2013-07-01

    Encoding semantic relationships between items on word lists (semantic processing) enhances true memories, but also increases memory distortions. Episodic memory impairments in schizophrenia (SZ) are strongly driven by failures to process semantic relations, but the exact nature of these relational semantic processing deficits is not well understood. Here, we used a false memory paradigm to investigate the impact of implicit and explicit semantic processing manipulations on episodic memory in SZ. Thirty SZ and 30 demographically matched healthy controls (HC) studied Deese/Roediger-McDermott (DRM) lists of semantically associated words. Half of the lists had strong implicit semantic associations and the remainder had low strength associations. Similarly, half of the lists were presented under "standard" instructions and the other half under explicit "relational processing" instructions. After study, participants performed recall and old/new recognition tests composed of targets, critical lures, and unrelated lures. HC exhibited higher true memories and better discriminability between true and false memory compared to SZ. High, versus low, associative strength increased false memory rates in both groups. However, explicit "relational processing" instructions positively improved true memory rates only in HC. Finally, true and false memory rates were associated with severity of disorganized and negative symptoms in SZ. These results suggest that reduced processing of semantic relationships during encoding in SZ may stem from an inability to implement explicit relational processing strategies rather than a fundamental deficit in the implicit activation and retrieval of word meanings from patients' semantic lexicon. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Central Nervous Insulin Signaling in Sleep-Associated Memory Formation and Neuroendocrine Regulation.

    Science.gov (United States)

    Feld, Gordon B; Wilhem, Ines; Benedict, Christian; Rüdel, Benjamin; Klameth, Corinna; Born, Jan; Hallschmid, Manfred

    2016-05-01

    The neurochemical underpinnings of sleep's contribution to the establishment and maintenance of memory traces are largely unexplored. Considering that intranasal insulin administration to the CNS improves memory functions in healthy and memory-impaired humans, we tested whether brain insulin signaling and sleep interact to enhance memory consolidation in healthy participants. We investigated the effect of intranasal insulin on sleep-associated neurophysiological and neuroendocrine parameters and memory consolidation in 16 men and 16 women (aged 18-30 years), who learned a declarative word-pair task and a procedural finger sequence tapping task in the evening before intranasal insulin (160 IU) or placebo administration and 8 h of nocturnal sleep. On the subsequent evening, they learned interfering word-pairs and a new finger sequence before retrieving the original memories. Insulin increased growth hormone concentrations in the first night-half and EEG delta power during the second 90 min of non-rapid-eye-movement sleep. Insulin treatment impaired the acquisition of new contents in both the declarative and procedural memory systems on the next day, whereas retrieval of original memories was unchanged. Results indicate that sleep-associated memory consolidation is not a primary mediator of insulin's acute memory-improving effect, but that the peptide acts on mechanisms that diminish the subsequent encoding of novel information. Thus, by inhibiting processes of active forgetting during sleep, central nervous insulin might reduce the interfering influence of encoding new information.

  3. Type II membrane protein CD69 regulates the formation of resting T-helper memory.

    OpenAIRE

    Shinoda, K.; Tokoyoda, K.; Hanazawa, A.; Hayashizaki, K.; Zehentmeier, S.; Hosokawa, H.; Iwamura, C.; Koseki, H.; Tumes, D. J.; Radbruch, A.; Nakayama, T.

    2012-01-01

    Memory T-helper (Th) lymphocytes are crucial for the maintenance of acquired immunity to eliminate infectious pathogens. We have previously demonstrated that most memory Th lymphocytes reside and rest on stromal niches of the bone marrow (BM). Little is known, however, regarding the molecular basis for the generation and maintenance of BM memory Th lymphocytes. Here we show that CD69-deficient effector CD4 T lymphocytes fail to relocate into and persist in the BM and therefore to differentiat...

  4. Increase in posterior alpha activity during rehearsal predicts successful long-term memory formation of word sequences.

    Science.gov (United States)

    Meeuwissen, Esther B; Takashima, Atsuko; Fernández, Guillén; Jensen, Ole

    2011-12-01

    It is becoming increasingly clear that demanding cognitive tasks rely on an extended network engaging task-relevant areas and, importantly, disengaging task-irrelevant areas. Given that alpha activity (8-12 Hz) has been shown to reflect the disengagement of task-irrelevant regions in attention and working memory tasks, we here ask if alpha activity plays a related role for long-term memory formation. Subjects were instructed to encode and maintain the order of word sequences while the ongoing brain activity was recorded using magnetoencephalography (MEG). In each trial, three words were presented followed by a 3.4 s rehearsal interval. Considering the good temporal resolution of MEG this allowed us to investigate the word presentation and rehearsal interval separately. The sequences were grouped in trials where word order either could be tested immediately (working memory trials; WM) or later (LTM trials) according to instructions. Subjects were tested on their ability to retrieve the order of the three words. The data revealed that alpha power in parieto-occipital regions was lower during word presentation compared to rehearsal. Our key finding was that parieto-occipital alpha power during the rehearsal period was markedly stronger for successfully than unsuccessfully encoded LTM sequences. This subsequent memory effect demonstrates that high posterior alpha activity creates an optimal brain state for successful LTM formation possibly by actively reducing parieto-occipital activity that might interfere with sequence encoding. Copyright © 2010 Wiley Periodicals, Inc.

  5. Proteolysis of proBDNF is a key regulator in the formation of memory.

    Directory of Open Access Journals (Sweden)

    Philip Barnes

    2008-09-01

    Full Text Available It is essential to understand the molecular processes underlying long-term memory to provide therapeutic targets of aberrant memory that produce pathological behaviour in humans. Under conditions of recall, fully-consolidated memories can undergo reconsolidation or extinction. These retrieval-mediated memory processes may rely on distinct molecular processes. The cellular mechanisms initiating the signature molecular events are not known. Using infusions of protein synthesis inhibitors, antisense oligonucleotide targeting brain-derived neurotrophic factor (BDNF mRNA or tPA-STOP (an inhibitor of the proteolysis of BDNF protein into the hippocampus of the awake rat, we show that acquisition and extinction of contextual fear memory depended on the increased and decreased proteolysis of proBDNF (precursor BDNF in the hippocampus, respectively. Conditions of retrieval that are known to initiate the reconsolidation of contextual fear memory, a BDNF-independent memory process, were not correlated with altered proBDNF cleavage. Thus, the processing of BDNF was associated with the acquisition of new information and the updating of information about a salient stimulus. Furthermore, the differential requirement for the processing of proBDNF by tPA in distinct memory processes suggest that the molecular events actively engaged to support the storage and/or the successful retrieval of memory depends on the integration of ongoing experience with past learning.

  6. Intrinsic monitoring of learning success facilitates memory encoding via the activation of the SN/VTA-Hippocampal loop

    Science.gov (United States)

    Ripollés, Pablo; Marco-Pallarés, Josep; Alicart, Helena; Tempelmann, Claus; Rodríguez-Fornells, Antoni; Noesselt, Toemme

    2016-01-01

    Humans constantly learn in the absence of explicit rewards. However, the neurobiological mechanisms supporting this type of internally-guided learning (without explicit feedback) are still unclear. Here, participants who completed a task in which no external reward/feedback was provided, exhibited enhanced fMRI-signals within the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop) when successfully grasping the meaning of new-words. Importantly, new-words that were better remembered showed increased activation and enhanced functional connectivity between the midbrain, hippocampus, and ventral striatum. Moreover, enhanced emotion-related physiological measures and subjective pleasantness ratings during encoding were associated with remembered new-words after 24 hr. Furthermore, increased subjective pleasantness ratings were also related to new-words remembered after seven days. These results suggest that intrinsic—potentially reward-related—signals, triggered by self-monitoring of correct performance, can promote the storage of new information into long-term memory through the activation of the SN/VTA-Hippocampal loop, possibly via dopaminergic modulation of the midbrain. DOI: http://dx.doi.org/10.7554/eLife.17441.001 PMID:27644419

  7. Intrinsic monitoring of learning success facilitates memory encoding via the activation of the SN/VTA-Hippocampal loop.

    Science.gov (United States)

    Ripollés, Pablo; Marco-Pallarés, Josep; Alicart, Helena; Tempelmann, Claus; Rodríguez-Fornells, Antoni; Noesselt, Toemme

    2016-09-20

    Humans constantly learn in the absence of explicit rewards. However, the neurobiological mechanisms supporting this type of internally-guided learning (without explicit feedback) are still unclear. Here, participants who completed a task in which no external reward/feedback was provided, exhibited enhanced fMRI-signals within the dopaminergic midbrain, hippocampus, and ventral striatum (the SN/VTA-Hippocampal loop) when successfully grasping the meaning of new-words. Importantly, new-words that were better remembered showed increased activation and enhanced functional connectivity between the midbrain, hippocampus, and ventral striatum. Moreover, enhanced emotion-related physiological measures and subjective pleasantness ratings during encoding were associated with remembered new-words after 24 hr. Furthermore, increased subjective pleasantness ratings were also related to new-words remembered after seven days. These results suggest that intrinsic-potentially reward-related-signals, triggered by self-monitoring of correct performance, can promote the storage of new information into long-term memory through the activation of the SN/VTA-Hippocampal loop, possibly via dopaminergic modulation of the midbrain.

  8. Memories.

    Science.gov (United States)

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  9. Detection of central circuits implicated in the formation of novel pain memories

    Directory of Open Access Journals (Sweden)

    Upadhyay J

    2016-09-01

    Full Text Available Jaymin Upadhyay,1 Julia Granitzka,1 Thomas Bauermann,2 Ulf Baumgärtner,3 Markus Breimhorst,1 Rolf-Detlef Treede,3 Frank Birklein1 1Department of Neurology, 2Department of Neuroradiology, University Medical Centre, Johannes Gutenberg University Mainz, Mainz, 3Department of Neurophysiology, Center for Biomedicine and Medical Technology Mannheim (CBTM, Heidelberg University, Mannheim, Germany Abstract: Being able to remember physically and emotionally painful events in one’s own past may shape behavior, and can create an aversion to a variety of situations. Pain imagination is a related process that may include recall of past experiences, in addition to production of sensory and emotional percepts without external stimuli. This study aimed to understand 1 the central nervous system processes that underlie pain imagination, 2 the retrieval of pain memories, and 3 to compare the latter with visual object memory. These goals were achieved by longitudinally investigating brain function with functional magnetic resonance imaging in a unique group of healthy volunteers who had never experienced tooth pain. In these subjects, we compared brain responses elicited during three experimental conditions in the following order: imagination of tooth pain (pain imagination, remembering one’s own house (object memory, and remembrance of tooth pain following an episode of induced acute tooth pain (pain memory. Key observations stemming from group-level conjunction analyses revealed common activation in the posterior parietal cortex for both pain imagination and pain memory, while object and pain memory each had strong activation predominantly within the middle frontal gyrus. When contrasting pain imagination and memory, significant activation differences were observed in subcortical structures (ie, parahippocampus – pain imagination > pain memory; midbrain – pain memory > pain imagination. Importantly, these findings were observed in the presence of

  10. Effects of Aging on True and False Memory Formation: An fMRI Study

    Science.gov (United States)

    Dennis, Nancy A.; Kim, Hongkeun; Cabeza, Roberto

    2007-01-01

    Compared to young, older adults are more likely to forget events that occurred in the past as well as remember events that never happened. Previous studies examining false memories and aging have shown that these memories are more likely to occur when new items share perceptual or semantic similarities with those presented during encoding. It is…

  11. Cognitive Backward Masking: A Window Into the Formation of a Short-Term Memory Trace

    NARCIS (Netherlands)

    Nieuwenstein, Mark; Wyble, Brad

    2012-01-01

    Working memory consolidation denotes the process that enables sensory information to be stored in short-term memory. What is currently unclear is how long this process takes and whether it continues after a stimulus has been masked. Here, we address these matters by examining whether the

  12. Context Memory Formation Requires Activity-Dependent Protein Degradation in the Hippocampus

    Science.gov (United States)

    Cullen, Patrick K.; Ferrara, Nicole C.; Pullins, Shane E.; Helmstetter, Fred J.

    2017-01-01

    Numerous studies have indicated that the consolidation of contextual fear memories supported by an aversive outcome like footshock requires de novo protein synthesis as well as protein degradation mediated by the ubiquitin-proteasome system (UPS). Context memory formed in the absence of an aversive stimulus by simple exposure to a novel…

  13. Endogenous BDNF Is Required for Long-Term Memory Formation in the Rat Parietal Cortex

    Science.gov (United States)

    Alonso, Mariana; Bekinschtein, Pedro, Cammarota, Martin; Vianna, Monica R. M.; Izquierdo, Ivan; Medina, Jorge H.

    2005-01-01

    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…

  14. The interaction of short-term and long-term memory in phonetic category formation

    Science.gov (United States)

    Harnsberger, James D.

    2002-05-01

    This study examined the role that short-term memory capacity plays in the relationship between novel stimuli (e.g., non-native speech sounds, native nonsense words) and phonetic categories in long-term memory. Thirty native speakers of American English were administered five tests: categorial AXB discrimination using nasal consonants from Malayalam; categorial identification, also using Malayalam nasals, which measured the influence of phonetic categories in long-term memory; digit span; nonword span, a short-term memory measure mediated by phonetic categories in long-term memory; and paired-associate word learning (word-word and word-nonword pairs). The results showed that almost all measures were significantly correlated with one another. The strongest predictor for the discrimination and word-nonword learning results was nonword (r=+0.62) and digit span (r=+0.51), respectively. When the identification test results were partialed out, only nonword span significantly correlated with discrimination. The results show a strong influence of short-term memory capacity on the encoding of phonetic detail within phonetic categories and suggest that long-term memory representations regulate the capacity of short-term memory to preserve information for subsequent encoding. The results of this study will also be discussed with regards to resolving the tension between episodic and abstract models of phonetic category structure.

  15. Natural variation in long-term memory formation among Nasonia parasitic wasp species

    NARCIS (Netherlands)

    Hoedjes, K.M.; Smid, H.M.

    2014-01-01

    Closely related species of parasitic wasps can differ substantially in memory dynamics. In this study we demonstrate differences in the number of conditioning trials required to form long-term memory between the closely related parasitic wasp species Nasonia vitripennis and Nasonia giraulti

  16. Age Differences in the Contribution of Recollection and Familiarity to False-Memory Formation: A New Paradigm to Examine Developmental Reversals

    Science.gov (United States)

    Lyons, Kristen E.; Ghetti, Simona; Cornoldi, Cesare

    2010-01-01

    Using a new method for studying the development of false-memory formation, we examined developmental differences in the rates at which 6-, 7-, 9-, 10-, and 18-year-olds made two types of memory errors: backward causal-inference errors (i.e. falsely remembering having viewed the non-viewed cause of a previously viewed effect), and gap-filling…

  17. [Supposed role of "metabolic memory" in formation of response reaction to stress-factors in young and adult organisms].

    Science.gov (United States)

    Bozhkov, A I; Dlubovskaia, V L; Dmitriev, Iu V; Meshaĭkina, N I; Maleev, V A; Klimova, E M

    2009-01-01

    The influence of the combined long-lasted influences of sulfur sulfate and diet restriction in young (3 month age) and adult (21 month age) Vistar rats on activity of glucose-6-phospatase, alaninaminotranspherase (ALT), aspartataminotranspherase (AST), and on phosphorilating activity of liver mitochondria was studied to investigate the role of metabolic memory on the peculiarities of response reaction. The young animals not differed from adult ones in the possibility of inducing activity of glucose-6-phospatase, ALT, and on phosphorilating activity after the influence of sulfur sulfate and diet restriction. The age-related differences in glucose-6-phospatase and transpherases and phosphorilating activity existing in control disappeared after the long-lasted action of sulfur sulfate and diet restriction. The answer reaction in enzyme activity to stress factors applied many times depends upon the metabolic memory formed in the process of adaptation, and the age of animals have no influence on it. In some relation the ontogenesis may be considered as a result of adaptation genesis. The metabolic memory can change the answer of the system to the stress influence. There are three types of modification of the answer to stress factors: the answer remains unchanged (metabolic memory), "paradox answer" formation, and super activation of the metabolic system.

  18. Interaction of Munc18c and syntaxin4 facilitates invadopodium formation and extracellular matrix invasion of tumor cells.

    Science.gov (United States)

    Brasher, Megan I; Martynowicz, David M; Grafinger, Olivia R; Hucik, Andrea; Shanks-Skinner, Emma; Uniacke, James; Coppolino, Marc G

    2017-09-29

    Tumor cell invasion involves targeted localization of proteins required for interactions with the extracellular matrix and for proteolysis. The localization of many proteins during these cell-extracellular matrix interactions relies on membrane trafficking mediated in part by SNAREs. The SNARE protein syntaxin4 (Stx4) is involved in the formation of invasive structures called invadopodia; however, it is unclear how Stx4 function is regulated during tumor cell invasion. Munc18c is known to regulate Stx4 activity, and here we show that Munc18c is required for Stx4-mediated invadopodium formation and cell invasion. Biochemical and microscopic analyses revealed a physical association between Munc18c and Stx4, which was enhanced during invadopodium formation, and that a reduction in Munc18c expression decreases invadopodium formation. We also found that an N-terminal Stx4-derived peptide associates with Munc18c and inhibits endogenous interactions of Stx4 with synaptosome-associated protein 23 (SNAP23) and vesicle-associated membrane protein 2 (VAMP2). Furthermore, expression of the Stx4 N-terminal peptide decreased invadopodium formation and cell invasion in vitro Of note, cells expressing the Stx4 N-terminal peptide exhibited impaired trafficking of membrane type 1 matrix metalloproteinase (MT1-MMP) and EGF receptor (EGFR) to the cell surface during invadopodium formation. Our findings implicate Munc18c as a regulator of Stx4-mediated trafficking of MT1-MMP and EGFR, advancing our understanding of the role of SNARE function in the localization of proteins that drive tumor cell invasion. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  19. A face to remember: emotional expression modulates prefrontal activity during memory formation.

    Science.gov (United States)

    Sergerie, Karine; Lepage, Martin; Armony, Jorge L

    2005-01-15

    Emotion can exert a modulatory role on episodic memory. Several studies have shown that negative stimuli (e.g., words, pictures) are better remembered than neutral ones. Although facial expressions are powerful emotional stimuli and have been shown to influence perception and attention processes, little is known about their effect on memory. We used functional magnetic resonance imaging (fMRI) in humans to investigate the effects of expression (happy, neutral, and fearful) on prefrontal cortex (PFC) activity during the encoding of faces, using a subsequent memory effect paradigm. Our results show that activity in right PFC predicted memory for faces, regardless of expression, while a homotopic region in the left hemisphere was associated with successful encoding only for faces with an emotional expression. These findings are consistent with the proposed role of right dorsolateral PFC in successful encoding of nonverbal material, but also suggest that left DLPFC may be a site where integration of memory and emotional processes occurs. This study sheds new light on the current controversy regarding the hemispheric lateralization of PFC in memory encoding.

  20. Elongator complex is required for long-term olfactory memory formation in Drosophila.

    Science.gov (United States)

    Yu, Dinghui; Tan, Ying; Chakraborty, Molee; Tomchik, Seth; Davis, Ronald L

    2018-04-01

    The evolutionarily conserved Elongator Complex associates with RNA polymerase II for transcriptional elongation. Elp3 is the catalytic subunit, contains histone acetyltransferase activity, and is associated with neurodegeneration in humans. Elp1 is a scaffolding subunit and when mutated causes familial dysautonomia. Here, we show that elp3 and elp1 are required for aversive long-term olfactory memory in Drosophila RNAi knockdown of elp3 in adult mushroom bodies impairs long-term memory (LTM) without affecting earlier forms of memory. RNAi knockdown with coexpression of elp3 cDNA reverses the impairment. Similarly, RNAi knockdown of elp1 impairs LTM and coexpression of elp1 cDNA reverses this phenotype. The LTM deficit in elp3 and elp1 knockdown flies is accompanied by the abolishment of a LTM trace, which is registered as increased calcium influx in response to the CS+ odor in the α-branch of mushroom body neurons. Coexpression of elp1 or elp3 cDNA rescues the memory trace in parallel with LTM. These data show that the Elongator complex is required in adult mushroom body neurons for long-term behavioral memory and the associated long-term memory trace. © 2018 Yu et al.; Published by Cold Spring Harbor Laboratory Press.

  1. Antibody formation in mouse bone marrow. II. Evidence for a memory-dependent phenomenon

    International Nuclear Information System (INIS)

    Benner, R.; Meima, F.; Meulen, G.M. van der

    1974-01-01

    Mouse bone marrow is barely capable of plaque-forming cell (PFC) activity in a primary response to sheep red blood cells (SRBC), while PFC activity in the secondary response to SRBC can be clearly demonstrated. This phenomenon was studied by means of cell transfer experiments. T cells, which are involved in an anti-SRBC PFC response, were shown to be very scarce in normal mouse bone marrow. This is considered to be the cause of the low PFC activity in the marrow during the primary response to SRBC. In normal mouse bone marrow precursors of IgM-PFC but not of IgG- and IgA-PFC could be found. Priming with SRBC induced the appearance of IgM-, IgG-, IgA- and T-memory cells in the marrow. These B- and T-memory cells were shown to be specific for the antigen which induced their appearance. It is thought that after a second injection of SRBC the IgM-, IgG- and IgA-memory cells can differentiate with the help of the T-memory cells within the bone marrow into IgM-, IgG- and IgA-PFC respectively. The sequence of appearance of the B-memory cells in the bone marrow was shown to be IgM--IgG--IgA. Six months after the intravenous injection of SRBC, the presence of B-memory cells could be demonstrated not only in spleen and bone marrow, but also in peripheral lymph nodes, mesenteric lymph node, Peyer's patches, thymus and blood. The increase in amount of B-memory cells was most prominent in the spleen

  2. Motor Skills Enhance Procedural Memory Formation and Protect against Age-Related Decline.

    Science.gov (United States)

    Müller, Nils C J; Genzel, Lisa; Konrad, Boris N; Pawlowski, Marcel; Neville, David; Fernández, Guillén; Steiger, Axel; Dresler, Martin

    2016-01-01

    The ability to consolidate procedural memories declines with increasing age. Prior knowledge enhances learning and memory consolidation of novel but related information in various domains. Here, we present evidence that prior motor experience-in our case piano skills-increases procedural learning and has a protective effect against age-related decline for the consolidation of novel but related manual movements. In our main experiment, we tested 128 participants with a sequential finger-tapping motor task during two sessions 24 hours apart. We observed enhanced online learning speed and offline memory consolidation for piano players. Enhanced memory consolidation was driven by a strong effect in older participants, whereas younger participants did not benefit significantly from prior piano experience. In a follow up independent control experiment, this compensatory effect of piano experience was not visible after a brief offline period of 30 minutes, hence requiring an extended consolidation window potentially involving sleep. Through a further control experiment, we rejected the possibility that the decreased effect in younger participants was caused by training saturation. We discuss our results in the context of the neurobiological schema approach and suggest that prior experience has the potential to rescue memory consolidation from age-related cognitive decline.

  3. Effects of 5-HT and insulin on learning and memory formation in food-deprived snails.

    Science.gov (United States)

    Aonuma, Hitoshi; Totani, Yuki; Kaneda, Mugiho; Nakamura, Ryota; Watanabe, Takayuki; Hatakeyama, Dai; Dyakonova, Varvara E; Lukowiak, Ken; Ito, Etsuro

    2018-02-01

    The pond snail Lymnaea stagnalis learns conditioned taste aversion (CTA) and consolidates it into long-term memory (LTM). How well they learn and form memory depends on the degree of food deprivation. Serotonin (5-HT) plays an important role in mediating feeding, and insulin enhances the memory consolidation process following CTA training. However, the relationship between these two signaling pathways has not been addressed. We measured the 5-HT content in the central nervous system (CNS) of snails subjected to different durations of food deprivation. One-day food-deprived snails, which exhibit the best learning and memory, had the lowest 5-HT content in the CNS, whereas 5-day food-deprived snails, which do not learn, had a high 5-HT content. Immersing 1-day food-deprived snails in 5-HT impaired learning and memory by causing an increase in 5-HT content, and that the injection of insulin into these snails reversed this impairment. We conclude that insulin rescues the CTA deficit and this may be due to a decrease in the 5-HT content in the CNS of Lymnaea. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Formation process of lamella structures by deformation in an Fe-Mn-Si-Cr-Ni shape memory alloy

    International Nuclear Information System (INIS)

    Kikuchi, T.; Kajiwara, S.; Tomota, Y.

    1995-01-01

    For Fe-Mn-Si-Cr-Ni shape memory alloys, it was previously found by HREM study that the formation of the nanometric lamella structures consisting of f.c.c. and h.c.p. phase is very important to exhibit good shape memory effect. In the present work, the formation process of such lamella structures has been studied in detail. The results are as follows. The transformation is initiated by random formation of extremely thin martensite plates with 1-2 nm width and then these plates are clustered and some of them coalesce to form thicker martensite plates with increasing deformation. The clustered regions are 400-600 nm wide and will correspond to the above mentioned lamella structures. These clustered regions are considered also to correspond to the thinnest martensite plate observable with optical microscope. In the optical microscopic scale, the thin martenite plates with the smallest width are formed rather uniformly in an austenite grain, and with further increasing deformation, they are clustered and coalesce into thicker plates with 3-8 μm width. (orig.)

  5. Npas4 Is a Critical Regulator of Learning-Induced Plasticity at Mossy Fiber-CA3 Synapses during Contextual Memory Formation

    DEFF Research Database (Denmark)

    Weng, Feng-Ju; Garcia, Rodrigo I; Lutzu, Stefano

    2018-01-01

    Synaptic connections between hippocampal mossy fibers (MFs) and CA3 pyramidal neurons are essential for contextual memory encoding, but the molecular mechanisms regulating MF-CA3 synapses during memory formation and the exact nature of this regulation are poorly understood. Here we report...... pyramidal cells that were activated by contextual learning and found that MF inputs on these cells were selectively strengthened. Deletion of Npas4 prevented both contextual memory formation and this learning-induced synaptic modification. We further show that Npas4 regulates MF-CA3 synapses by controlling...... the expression of the polo-like kinase Plk2. Thus, Npas4 is a critical regulator of experience-dependent, structural, and functional plasticity at MF-CA3 synapses during contextual memory formation....

  6. Formation of visual memories controlled by gamma power phase-locked to alpha oscillations

    Science.gov (United States)

    Park, Hyojin; Lee, Dong Soo; Kang, Eunjoo; Kang, Hyejin; Hahm, Jarang; Kim, June Sic; Chung, Chun Kee; Jiang, Haiteng; Gross, Joachim; Jensen, Ole

    2016-06-01

    Neuronal oscillations provide a window for understanding the brain dynamics that organize the flow of information from sensory to memory areas. While it has been suggested that gamma power reflects feedforward processing and alpha oscillations feedback control, it remains unknown how these oscillations dynamically interact. Magnetoencephalography (MEG) data was acquired from healthy subjects who were cued to either remember or not remember presented pictures. Our analysis revealed that in anticipation of a picture to be remembered, alpha power decreased while the cross-frequency coupling between gamma power and alpha phase increased. A measure of directionality between alpha phase and gamma power predicted individual ability to encode memory: stronger control of alpha phase over gamma power was associated with better memory. These findings demonstrate that encoding of visual information is reflected by a state determined by the interaction between alpha and gamma activity.

  7. Who is the boss? Individual recognition memory and social hierarchy formation in crayfish.

    Science.gov (United States)

    Jiménez-Morales, Nayeli; Mendoza-Ángeles, Karina; Porras-Villalobos, Mercedes; Ibarra-Coronado, Elizabeth; Roldán-Roldán, Gabriel; Hernández-Falcón, Jesús

    2018-01-01

    Under laboratory conditions, crayfish establish hierarchical orders through agonistic encounters whose outcome defines the dominant one and one, or more, submissive animals. These agonistic encounters are ritualistic, based on threats, pushes, attacks, grabs, and avoidance behaviors that include retreats and escape responses. Agonistic behavior in a triad of unfamiliar, size-matched animals is intense on the first day of social interaction and the intensity fades on daily repetitions. The dominant animal keeps its status for long periods, and the submissive ones seem to remember 'who the boss is'. It has been assumed that animals remember and recognize their hierarchical status by urine signals, but the putative substance mediating this recognition has not been reported. The aim of this work was to characterize this hierarchical recognition memory. Triads of unfamiliar crayfish (male animals, size and weight-matched) were faced during standardized agonistic protocols for five consecutive days to analyze memory acquisition dynamics (Experiment 1). In Experiment 2, dominant crayfish were shifted among triads to disclose whether hierarchy depended upon individual recognition memory or recognition of status. The maintenance of the hierarchical structure without behavioral reinforcement was assessed by immobilizing the dominant animal during eleven daily agonistic encounters, and considering any shift in the dominance order (Experiment 3). Standard amnesic treatments (anisomycin, scopolamine or cold-anesthesia) were given to all members of the triads immediately after the first interaction session to prevent individual recognition memory consolidation and evaluate its effect on the hierarchical order (Experiment 4). Acquisition of hierarchical recognition occurs at the first agonistic encounter and agonistic behavior gradually diminishes in the following days; animals keep their hierarchical order despite the inability of the dominant crayfish to attack the submissive

  8. EphrinA4 mimetic peptide targeted to EphA binding site impairs the formation of long-term fear memory in lateral amygdala.

    Science.gov (United States)

    Dines, M; Lamprecht, R

    2014-09-30

    Fear conditioning leads to long-term fear memory formation and is a model for studying fear-related psychopathologies conditions such as phobias and posttraumatic stress disorder. Long-term fear memory formation is believed to involve alterations of synaptic efficacy mediated by changes in synaptic transmission and morphology in lateral amygdala (LA). EphrinA4 and its cognate Eph receptors are intimately involved in regulating neuronal morphogenesis, synaptic transmission and plasticity. To assess possible roles of ephrinA4 in fear memory formation we designed and used a specific inhibitory ephrinA4 mimetic peptide (pep-ephrinA4) targeted to EphA binding site. We show that this peptide, composed of the ephrinA4 binding domain, interacts with EphA4 and inhibits ephrinA4-induced phosphorylation of EphA4. Microinjection of the pep-ephrinA4 into rat LA 30 min before training impaired long- but not short-term fear conditioning memory. Microinjection of a control peptide derived from a nonbinding E helix site of ephrinA4, that does not interact with EphA, had no effect on fear memory formation. Microinjection of pep-ephrinA4 into areas adjacent to the amygdala had no effect on fear memory. Acute systemic administration of pep-ephrinA4 1 h after training also impaired long-term fear conditioning memory formation. These results demonstrate that ephrinA4 binding sites in LA are essential for long-term fear memory formation. Moreover, our research shows that ephrinA4 binding sites may serve as a target for pharmacological treatment of fear and anxiety disorders.

  9. Focal and temporal release of glutamate in the mushroom bodies improves olfactory memory in Apis mellifera.

    Science.gov (United States)

    Locatelli, Fernando; Bundrock, Gesine; Müller, Uli

    2005-12-14

    In contrast to vertebrates, the role of the neurotransmitter glutamate in learning and memory in insects has hardly been investigated. The reason is that a pharmacological characterization of insect glutamate receptors is still missing; furthermore, it is difficult to locally restrict pharmacological interventions. In this study, we overcome these problems by using locally and temporally defined photo-uncaging of glutamate to study its role in olfactory learning and memory formation in the honeybee, Apis mellifera. Uncaging glutamate in the mushroom bodies immediately after a weak training protocol induced a higher memory rate 2 d after training, mimicking the effect of a strong training protocol. Glutamate release before training does not facilitate memory formation, suggesting that glutamate mediates processes triggered by training and required for memory formation. Uncaging glutamate in the antennal lobes shows no effect on memory formation. These results provide the first direct evidence for a temporally and locally restricted function of glutamate in memory formation in honeybees and insects.

  10. Neuromodulation: acetylcholine and memory consolidation.

    Science.gov (United States)

    Hasselmo

    1999-09-01

    Clinical and experimental evidence suggests that hippocampal damage causes more severe disruption of episodic memories if those memories were encoded in the recent rather than the more distant past. This decrease in sensitivity to damage over time might reflect the formation of multiple traces within the hippocampus itself, or the formation of additional associative links in entorhinal and association cortices. Physiological evidence also supports a two-stage model of the encoding process in which the initial encoding occurs during active waking and deeper consolidation occurs via the formation of additional memory traces during quiet waking or slow-wave sleep. In this article I will describe the changes in cholinergic tone within the hippocampus in different stages of the sleep-wake cycle and will propose that these changes modulate different stages of memory formation. In particular, I will suggest that the high levels of acetylcholine that are present during active waking might set the appropriate dynamics for encoding new information in the hippocampus, by partially suppressing excitatory feedback connections and so facilitating encoding without interference from previously stored information. By contrast, the lower levels of acetylcholine that are present during quiet waking and slow-wave sleep might release this suppression and thereby allow a stronger spread of activity within the hippocampus itself and from the hippocampus to the entorhinal cortex, thus facilitating the process of consolidation of separate memory traces.

  11. Gamma neurons mediate dopaminergic input during aversive olfactory memory formation in Drosophila.

    Science.gov (United States)

    Qin, Hongtao; Cressy, Michael; Li, Wanhe; Coravos, Jonathan S; Izzi, Stephanie A; Dubnau, Joshua

    2012-04-10

    Mushroom body (MB)-dependent olfactory learning in Drosophila provides a powerful model to investigate memory mechanisms. MBs integrate olfactory conditioned stimulus (CS) inputs with neuromodulatory reinforcement (unconditioned stimuli, US), which for aversive learning is thought to rely on dopaminergic (DA) signaling to DopR, a D1-like dopamine receptor expressed in MBs. A wealth of evidence suggests the conclusion that parallel and independent signaling occurs downstream of DopR within two MB neuron cell types, with each supporting half of memory performance. For instance, expression of the Rutabaga (Rut) adenylyl cyclase in γ neurons is sufficient to restore normal learning to rut mutants, whereas expression of Neurofibromatosis 1 (NF1) in α/β neurons is sufficient to rescue NF1 mutants. DopR mutations are the only case where memory performance is fully eliminated, consistent with the hypothesis that DopR receives the US inputs for both γ and α/β lobe traces. We demonstrate, however, that DopR expression in γ neurons is sufficient to fully support short- and long-term memory. We argue that DA-mediated CS-US association is formed in γ neurons followed by communication between γ and α/β neurons to drive consolidation. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Insulin Receptor Substrate 2 Is a Negative Regulator of Memory Formation

    Science.gov (United States)

    Irvine, Elaine E.; Drinkwater, Laura; Radwanska, Kasia; Al-Qassab, Hind; Smith, Mark A.; O'Brien, Melissa; Kielar, Catherine; Choudhury, Agharul I.; Krauss, Stefan; Cooper, Jonathan D.; Withers, Dominic J.; Giese, Karl Peter

    2011-01-01

    Insulin has been shown to impact on learning and memory in both humans and animals, but the downstream signaling mechanisms involved are poorly characterized. Insulin receptor substrate-2 (Irs2) is an adaptor protein that couples activation of insulin- and insulin-like growth factor-1 receptors to downstream signaling pathways. Here, we have…

  13. Effects of Presentation Format and List Length on Children's False Memories

    Science.gov (United States)

    Swannell, Ellen R.; Dewhurst, Stephen A.

    2013-01-01

    The effect of list length on children's false memories was investigated using list and story versions of the Deese/Roediger-McDermott procedure. Short (7 items) and long (14 items) sequences of semantic associates were presented to children aged 6, 8, and 10 years old either in lists or embedded within a story that emphasized the list theme.…

  14. Natural variation in memory formation among Nasonia parasitic wasps : from genes to behaviour

    NARCIS (Netherlands)

    Hoedjes, K.M.

    2014-01-01

    The ability to learn and form memory has been demonstrated in various animal species, ranging from relatively simple invertebrates, such as snails and insects, to more complex vertebrate species, including birds and mammals. The opportunity to acquire new skills or to adapt behaviour

  15. Revisiting the Effect of Reminders on Infants' Media Memories: Does the Encoding Format Matter?

    Science.gov (United States)

    Barr, Rachel; Brito, Natalie; Simcock, Gabrielle

    2013-01-01

    With the present research, the authors examined whether reminders could maintain 18-month-olds' memories generated from picture books and videos. Infants (N = 98) were shown a series of target actions in a picture book or on video. Either 24 hr or 2 weeks prior to a 4-week deferred imitation test, they were exposed to a reminder, a partial…

  16. Ontogeny of Contextual Fear Memory Formation, Specificity, and Persistence in Mice

    Science.gov (United States)

    Akers, Katherine G.; Arruda-Carvalho, Maithe; Josselyn, Sheena A.; Frankland, Paul W.

    2012-01-01

    Pinpointing the precise age when young animals begin to form memories of aversive events is valuable for understanding the onset of anxiety and mood disorders and for detecting early cognitive impairment in models of childhood-onset disorders. Although these disorders are most commonly modeled in mice, we know little regarding the development of…

  17. γ neurons mediate dopaminergic input during aversive olfactory memory formation in Drosophila

    Science.gov (United States)

    Qin, H.; Cressy, M.; Li, W.; Coravos, J.; Izzi, S.; Dubnau, J.

    2012-01-01

    SUMMARY Mushroom body (MB) dependent olfactory learning in Drosophila provides a powerful model to investigate memory mechanisms. MBs integrate olfactory conditioned stimuli (CS) inputs with neuromodulatory reinforcement (unconditioned stimuli, US) [1, 2], which for aversive learning is thought to rely on dopaminergic (DA) signaling [3–6] to DopR, a D1-like dopamine receptor expressed in MB [7, 8]. A wealth of evidence suggests the conclusion that parallel and independent signaling occurs downstream of DopR within two MB neuron cell types, with each supporting half of memory performance. For instance, expression of the rutabaga adenylyl cyclase (rut) in γ neurons is sufficient to restore normal learning to rut mutants [9] whereas expression of Neurofibromatosis I (NFI) in α/β neurons is sufficient to rescue NF1 mutants [10, 11]. DopR mutations are the only case where memory performance is fully eliminated [7], consistent with the hypothesis that DopR receives the US inputs for both γ and α/β lobe traces. We demonstrate, however, that DopR expression in γ neurons is sufficient to fully support short (STM) and long-term memory (LTM). We argue that DA-mediated CS-US association is formed in γ neurons followed by communication between γ and α/β neurons to drive consolidation. PMID:22425153

  18. Effects of Electroacupuncture on Learning, Memory and Formation System of Free Radicals in Brain Tissues of Vascular Dementia Model Rats

    Institute of Scientific and Technical Information of China (English)

    王黎; 唐纯志; 赖新生

    2004-01-01

    In order to observe the regulative effect of electro-acupuncture on the formation system of free radicals in the brain tissues and learning and memory in vascular dementia (VD) model rats, the Morris's water labyrinth was used for testing the learning ability and memory in VD model rats made by 4-vessel occlusion method, and the activities or contents of nitric oxide (NO), NO synthase (NOS), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH-Px) were determined. Results showed that the mean escape latency in the electro-acupuncture group was markedly reduced in place test, and the times swam the place of the plate-form in the original plate-form quadrant were significantly more than those in the rest three quadrants in spatia1 probe test as compared with the model group. In the electro-acupuncture group and the nimodipine group the contents of NO and MDA and the activity of NOS were decreased, while the activities of SOD and GSH-Px were increased. It is indicated that electro-acupuncture can modulate the production and clearance of free radicals, and improve the ability of learning and memory of the VD model rats.

  19. Lack of CRH Affects the Behavior but Does Not Affect the Formation of Short-Term Memory.

    Science.gov (United States)

    Varejkova, Eva; Plananska, Eva; Myslivecek, Jaromir

    2018-01-01

    Corticotropin-releasing hormone (CRH) is involved in modification of synaptic transmission and affects spatial discrimination learning, i.e., affects the formation of memory in long-term aspect. Therefore, we have focused on CRH effect on short-term memory. We have used stress task avoidance (maze containing three zones: entrance, aversive, and neutral) and compared the behavior and short-term memory in wild-type mice and mice lacking CRH (CRH KO) experiencing one 120-min session of restraint stress. As control, non-stressed animals were used. As expected, the animals that experienced the stress situation tend to spend less time in the zone in which the restraint chamber was present. The animals spent more time in the neutral zone. There were significant differences in number of freezing bouts in the aversive and entrance zones in CRH KO animals. CRH KO control animals entered the neutral zone much more faster than WT control and spent more time immobile in the neutral zone than WT control. These data give evidence that lacking of CRH itself improves the ability of mice to escape away from potentially dangerous area (i.e., those in which the scent of stressed animal is present).

  20. Opiate exposure state controls dopamine D3 receptor and cdk5/calcineurin signaling in the basolateral amygdala during reward and withdrawal aversion memory formation.

    Science.gov (United States)

    Rosen, Laura G; Rushlow, Walter J; Laviolette, Steven R

    2017-10-03

    The dopamine (DA) D3 receptor (D3R) is highly expressed in the basolateral nucleus of the amygdala (BLA), a neural region critical for processing opiate-related reward and withdrawal aversion-related memories. Functionally, D3R transmission is linked to downstream Cdk5 and calcineurin signaling, both of which regulate D3R activity states and play critical roles in memory-related synaptic plasticity. Previous evidence links D3R transmission to opiate-related memory processing, however little is known regarding how chronic opiate exposure may alter D3R-dependent memory mechanisms. Using conditioned place preference (CPP) and withdrawal aversion (conditioned place aversion; CPA) procedures in rats, combined with molecular analyses of BLA protein expression, we examined the effects of chronic opiate exposure on the functional role of intra-BLA D3R transmission during the acquisition of opiate reward or withdrawal aversion memories. Remarkably, we report that the state of opiate exposure during behavioural conditioning (opiate-naïve/non-dependent vs. chronically exposed and in withdrawal) controlled the functional role of intra-BLA D3R transmission during the acquisition of both opiate reward memories and withdrawal-aversion associative memories. Thus, whereas intra-BLA D3R blockade had no effect on opiate reward memory formation in the non-dependent state, blockade of intra-BLA D3R transmission prevented the formation of opiate reward and withdrawal aversion memory in the chronically exposed state. This switch in the functional role of D3R transmission corresponded to significant increases in Cdk5 phosphorylation and total expression levels of calcineurin, and a corresponding decrease in intra-BLA D3R expression. Inhibition of either intra-BLA Cdk5 or calcineurin reversed these effects, switching intra-BLA associative memory formation back to a D3R-independent mechanism. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Experience-driven formation of parts-based representations in a model of layered visual memory

    Directory of Open Access Journals (Sweden)

    Jenia Jitsev

    2009-09-01

    Full Text Available Growing neuropsychological and neurophysiological evidence suggests that the visual cortex uses parts-based representations to encode, store and retrieve relevant objects. In such a scheme, objects are represented as a set of spatially distributed local features, or parts, arranged in stereotypical fashion. To encode the local appearance and to represent the relations between the constituent parts, there has to be an appropriate memory structure formed by previous experience with visual objects. Here, we propose a model how a hierarchical memory structure supporting efficient storage and rapid recall of parts-based representations can be established by an experience-driven process of self-organization. The process is based on the collaboration of slow bidirectional synaptic plasticity and homeostatic unit activity regulation, both running at the top of fast activity dynamics with winner-take-all character modulated by an oscillatory rhythm. These neural mechanisms lay down the basis for cooperation and competition between the distributed units and their synaptic connections. Choosing human face recognition as a test task, we show that, under the condition of open-ended, unsupervised incremental learning, the system is able to form memory traces for individual faces in a parts-based fashion. On a lower memory layer the synaptic structure is developed to represent local facial features and their interrelations, while the identities of different persons are captured explicitly on a higher layer. An additional property of the resulting representations is the sparseness of both the activity during the recall and the synaptic patterns comprising the memory traces.

  2. Orientation dependence of stress-induced martensite formation during nanoindentation in NiTi shape memory alloys

    International Nuclear Information System (INIS)

    Laplanche, G.; Pfetzing-Micklich, J.; Eggeler, G.

    2014-01-01

    In the present work we used nanoindentation with a spherical indenter tip to study the formation of stress-induced martensite in NiTi shape memory alloys. Prior to nanoindentation, orientation imaging was performed to select austenite grains with specific crystallographic orientations, including the principal crystallographic directions [0 0 1], [1 0 1] and [1 1 1]. We studied a material where stress-induced martensite is stable at room temperature and found surface patterns with four-, two- and threefold symmetries for the [0 0 1], [1 0 1] and [1 1 1] crystallographic indentation directions, respectively. Atomic force microscopy investigations of the topography showed that the surface patterns were associated with sink-ins. The crystallographic sink-in patterns disappeared during heating, which proved their martensitic origin. Our results provide clear experimental evidence which shows that the crystallographic anisotropy of nanoindentation is governed by the crystallographic anisotropy of the stress-induced formation of martensite

  3. Vitamin B1-deficient mice show impairment of hippocampus-dependent memory formation and loss of hippocampal neurons and dendritic spines: potential microendophenotypes of Wernicke-Korsakoff syndrome.

    Science.gov (United States)

    Inaba, Hiroyoshi; Kishimoto, Takuya; Oishi, Satoru; Nagata, Kan; Hasegawa, Shunsuke; Watanabe, Tamae; Kida, Satoshi

    2016-12-01

    Patients with severe Wernicke-Korsakoff syndrome (WKS) associated with vitamin B1 (thiamine) deficiency (TD) show enduring impairment of memory formation. The mechanisms of memory impairment induced by TD remain unknown. Here, we show that hippocampal degeneration is a potential microendophenotype (an endophenotype of brain disease at the cellular and synaptic levels) of WKS in pyrithiamine-induced thiamine deficiency (PTD) mice, a rodent model of WKS. PTD mice show deficits in the hippocampus-dependent memory formation, although they show normal hippocampus-independent memory. Similarly with WKS, impairments in memory formation did not recover even at 6 months after treatment with PTD. Importantly, PTD mice exhibit a decrease in neurons in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus and reduced density of wide dendritic spines in the DG. Our findings suggest that TD induces hippocampal degeneration, including the loss of neurons and spines, thereby leading to enduring impairment of hippocampus-dependent memory formation.

  4. Vitamin B1-deficient mice show impairment of hippocampus-dependent memory formation and loss of hippocampal neurons and dendritic spines: potential microendophenotypes of Wernicke–Korsakoff syndrome

    Science.gov (United States)

    Inaba, Hiroyoshi; Kishimoto, Takuya; Oishi, Satoru; Nagata, Kan; Hasegawa, Shunsuke; Watanabe, Tamae; Kida, Satoshi

    2016-01-01

    Patients with severe Wernicke–Korsakoff syndrome (WKS) associated with vitamin B1 (thiamine) deficiency (TD) show enduring impairment of memory formation. The mechanisms of memory impairment induced by TD remain unknown. Here, we show that hippocampal degeneration is a potential microendophenotype (an endophenotype of brain disease at the cellular and synaptic levels) of WKS in pyrithiamine-induced thiamine deficiency (PTD) mice, a rodent model of WKS. PTD mice show deficits in the hippocampus-dependent memory formation, although they show normal hippocampus-independent memory. Similarly with WKS, impairments in memory formation did not recover even at 6 months after treatment with PTD. Importantly, PTD mice exhibit a decrease in neurons in the CA1, CA3, and dentate gyrus (DG) regions of the hippocampus and reduced density of wide dendritic spines in the DG. Our findings suggest that TD induces hippocampal degeneration, including the loss of neurons and spines, thereby leading to enduring impairment of hippocampus-dependent memory formation. PMID:27576603

  5. Pharmacological evidence that both cognitive memory and habit formation contribute to within-session learning of concurrent visual discriminations.

    Science.gov (United States)

    Turchi, Janita; Devan, Bryan; Yin, Pingbo; Sigrist, Emmalynn; Mishkin, Mortimer

    2010-07-01

    The monkey's ability to learn a set of visual discriminations presented concurrently just once a day on successive days (24-h ITI task) is based on habit formation, which is known to rely on a visuo-striatal circuit and to be independent of visuo-rhinal circuits that support one-trial memory. Consistent with this dissociation, we recently reported that performance on the 24-h ITI task is impaired by a striatal-function blocking agent, the dopaminergic antagonist haloperidol, and not by a rhinal-function blocking agent, the muscarinic cholinergic antagonist scopolamine. In the present study, monkeys were trained on a short-ITI form of concurrent visual discrimination learning, one in which a set of stimulus pairs is repeated not only across daily sessions but also several times within each session (in this case, at about 4-min ITIs). Asymptotic discrimination learning rates in the non-drug condition were reduced by half, from approximately 11 trials/pair on the 24-h ITI task to approximately 5 trials/pair on the 4-min ITI task, and this faster learning was impaired by systemic injections of either haloperidol or scopolamine. The results suggest that in the version of concurrent discrimination learning used here, the short ITIs within a session recruit both visuo-rhinal and visuo-striatal circuits, and that the final performance level is driven by both cognitive memory and habit formation working in concert.

  6. Mechanisms of visual memory formation in bees: About immediate early genes and synaptic plasticity

    OpenAIRE

    Sommerlandt, Frank M. J.

    2016-01-01

    Animals form perceptual associations through processes of learning, and retain that information through mechanisms of memory. Honeybees and bumblebees are classic models for insect perception and learning, and despite their small brains with about one million neurons, they are organized in highly social colonies and possess an astonishing rich behavioral repertoire including navigation, communication and cognition. Honeybees are able to harvest hundreds of morphologically divergent flower typ...

  7. Baseline frontostriatal-limbic connectivity predicts reward-based memory formation.

    Science.gov (United States)

    Hamann, Janne M; Dayan, Eran; Hummel, Friedhelm C; Cohen, Leonardo G

    2014-12-01

    Reward mediates the acquisition and long-term retention of procedural skills in humans. Yet, learning under rewarded conditions is highly variable across individuals and the mechanisms that determine interindividual variability in rewarded learning are not known. We postulated that baseline functional connectivity in a large-scale frontostriatal-limbic network could predict subsequent interindividual variability in rewarded learning. Resting-state functional MRI was acquired in two groups of subjects (n = 30) who then trained on a visuomotor procedural learning task with or without reward feedback. We then tested whether baseline functional connectivity within the frontostriatal-limbic network predicted memory strength measured immediately, 24 h and 1 month after training in both groups. We found that connectivity in the frontostriatal-limbic network predicted interindividual variability in the rewarded but not in the unrewarded learning group. Prediction was strongest for long-term memory. Similar links between connectivity and reward-based memory were absent in two control networks, a fronto-parieto-temporal language network and the dorsal attention network. The results indicate that baseline functional connectivity within the frontostriatal-limbic network successfully predicts long-term retention of rewarded learning. © 2014 Wiley Periodicals, Inc.

  8. Activity of human hippocampal formation and amygdala neurons during memory testing.

    Science.gov (United States)

    Halgren, E; Babb, T L; Crandall, P H

    1978-11-01

    Single and multiple unit recordings were made from fine wires stereotaxically implanted in the hippocampus (HC), hippocampal gyrus (HCG), and amygdala (Am) of psychomotor epileptics. During a series of memory and control tests presented on slides, 21 of 155 HCG units, 15 of 59 HC units, and 2 of 54 Am units showed what appeared to be simple phasic or tonic visual responses. Twenty-seven other units, found only in the HCG, changed firing only during slides requiring a choice ('choice units'). A given choice unit responded during choices indicated verbally or manually, and during tasks requiring recall of Recent Memory, various visual discriminations, and expressions of preference. Choice units were not affected by sensory stimulation or motor activity in contexts not requiring choice. Phasically inhibited choice units had higher firing rates and lower signal-to-noise ratios than tonically excited units. Whether an electrode recorded a choice unit was unrelated to if it recorded a response to hyperventilation, or was in an area of epileptic pathology. Recordings were also made during an interview lasting several hours and eliciting a wide range of behaviors. Five of the 131 HCG units fired in repeated extended bursts, at least 50 times background during recall of word pairs or of the patient's hospital room. The unit response did not occur during numerous control tasks possessing similar overt sensory, motor, and social concomitants, but not requiring Recent Memory.

  9. Impaired spatial and contextual memory formation in galectin-1 deficient mice

    Directory of Open Access Journals (Sweden)

    Sakaguchi Masanori

    2011-09-01

    Full Text Available Abstract Galectins are a 15 member family of carbohydrate-binding proteins that have been implicated in cancer, immunity, inflammation and development. While galectins are expressed in the central nervous system, little is known about their function in the adult brain. Previously we have shown that galectin-1 (gal-1 is expressed in the adult hippocampus, and, in particular, in putative neural stem cells in the subgranular zone. To evaluate how gal-1 might contribute to hippocampal memory function here we studied galectin-1 null mutant (gal-1-/- mice. Compared to their wildtype littermate controls, gal-1-/- mice exhibited impaired spatial learning in the water maze and contextual fear learning. Interestingly, tone fear conditioning was normal in gal-1-/- mice suggesting that loss of gal-1 might especially impact hippocampal learning and memory. Furthermore, gal-1-/- mice exhibited normal motor function, emotion and sensory processing in a battery of other behavioral tests, suggesting that non-mnemonic performance deficits are unlikely to account for the spatial and contextual learning deficits. Together, these data reveal a role for galectin-carbohydrate signalling in hippocampal memory function.

  10. Does animal-mediated seed dispersal facilitate the formation of Pinus armandii-Quercus aliena var. acuteserrata forests?

    Science.gov (United States)

    Yu, Fei; Wang, Dexiang; Yi, Xianfeng; Shi, Xiaoxiao; Huang, Yakun; Zhang, Hongwu; Zhang, XinPing

    2014-01-01

    The Pinus armandii and Quercus aliena var. acuteserrata mixed forest is one of the major forest types in the Qinling Mountains, China. P. armandii is considered to be a pioneer species during succession and it is usually invaded by late successional Q. aliena var. acuteserrata. However, the mechanism that underlies its invasion remains unclear. In the present study, we tracked seed dispersal of P. armandii and Q. aliena var. acuteserrata using coded plastic tags in the western, middle and eastern Qinling Mountains to elucidate the invasion process in the mixed forests. Our results indicated that the seeds of both P. armandii and Q. aliena var. acuteserrata were removed rapidly in the Qinling Mountains, and there were no differences in the seed removal rates between the two species. There were significant differences in rodent seed-eating and caching strategies between the two tree species. For P. armandii, seeds were more likely to be eaten in situ than those of Q. aliena var. acuteserrata in all plots. By contrast, the acorns of Q. aliena var. acuteserrata were less frequently eaten in situ, but more likely to be removed and cached. Q. aliena var. acuteserrata acorns had significantly longer dispersal distances than P. armandii seeds in all plots. Although P. armandii seeds were less likely to be dispersed into the Q. aliena var. acuteserrata stands, over 30% of the released acorns were transported into the P. armandii stands where they established five seedlings. Based on the coupled recruitment patterns of P. armandii and Q. aliena var. acuteserrata, we suggest that the animal-mediated seed dispersal contributes to the formation of Pinus armandii-Quercus aliena var. acuteserrata forests.

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

    OpenAIRE

    Falibene, Agustina; Roces, Flavio; R?ssler, Wolfgang

    2015-01-01

    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...

  12. A homolog of the vertebrate pituitary adenylate cyclase-activating polypeptide is both necessary and instructive for the rapid formation of associative memory in an invertebrate

    OpenAIRE

    Pirger, Zsolt; László, Zita; Kemenes, Ildikó; Tóth, Gábor; Reglődi, Dóra; Kemenes, György

    2010-01-01

    Similar to other invertebrate and vertebrate animals, cAMP dependent signaling cascades are key components of long-term memory (LTM) formation in the snail Lymnaea stagnalis, an established experimental model for studying evolutionarily conserved molecular mechanisms of long-term associative memory. Although a great deal is already known about the signaling cascades activated by cAMP, the molecules involved in the learning-induced activation of adenylate cyclase (AC) in Lymnaea remained unkno...

  13. Elongation factor Ts directly facilitates the formation and disassembly of the Escherichia coli elongation factor Tu·GTP·aminoacyl-tRNA ternary complex.

    Science.gov (United States)

    Burnett, Benjamin J; Altman, Roger B; Ferrao, Ryan; Alejo, Jose L; Kaur, Navdep; Kanji, Joshua; Blanchard, Scott C

    2013-05-10

    Aminoacyl-tRNA (aa-tRNA) enters the ribosome in a ternary complex with the G-protein elongation factor Tu (EF-Tu) and GTP. EF-Tu·GTP·aa-tRNA ternary complex formation and decay rates are accelerated in the presence of the nucleotide exchange factor elongation factor Ts (EF-Ts). EF-Ts directly facilitates the formation and disassociation of ternary complex. This system demonstrates a novel function of EF-Ts. Aminoacyl-tRNA enters the translating ribosome in a ternary complex with elongation factor Tu (EF-Tu) and GTP. Here, we describe bulk steady state and pre-steady state fluorescence methods that enabled us to quantitatively explore the kinetic features of Escherichia coli ternary complex formation and decay. The data obtained suggest that both processes are controlled by a nucleotide-dependent, rate-determining conformational change in EF-Tu. Unexpectedly, we found that this conformational change is accelerated by elongation factor Ts (EF-Ts), the guanosine nucleotide exchange factor for EF-Tu. Notably, EF-Ts attenuates the affinity of EF-Tu for GTP and destabilizes ternary complex in the presence of non-hydrolyzable GTP analogs. These results suggest that EF-Ts serves an unanticipated role in the cell of actively regulating the abundance and stability of ternary complex in a manner that contributes to rapid and faithful protein synthesis.

  14. Trial-by-Trial Modulation of Associative Memory Formation by Reward Prediction Error and Reward Anticipation as Revealed by a Biologically Plausible Computational Model.

    Science.gov (United States)

    Aberg, Kristoffer C; Müller, Julia; Schwartz, Sophie

    2017-01-01

    Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activity of the dopaminergic system, i.e., prediction errors and expected values, is scarce and inconclusive. For example, different previous studies reported that the magnitude of prediction errors during a reinforcement learning task was a positive, negative, or non-significant predictor of successfully encoding simultaneously presented images. Individual sensitivities to reward and punishment have been found to influence the activation of the dopaminergic reward system and could therefore help explain these seemingly discrepant results. Here, we used a novel associative memory task combined with computational modeling and showed independent effects of reward-delivery and reward-anticipation on memory. Strikingly, the computational approach revealed positive influences from both reward delivery, as mediated by prediction error magnitude, and reward anticipation, as mediated by magnitude of expected value, even in the absence of behavioral effects when analyzed using standard methods, i.e., by collapsing memory performance across trials within conditions. We additionally measured trait estimates of reward and punishment sensitivity and found that individuals with increased reward (vs. punishment) sensitivity had better memory for associations encoded during positive (vs. negative) prediction errors when tested after 20 min, but a negative trend when tested after 24 h. In conclusion, modeling trial-by-trial fluctuations in the magnitude of reward, as we did here for prediction errors and expected value computations, provides a comprehensive and biologically plausible description of

  15. Social Memory Formation Rapidly and Differentially Affects the Motivation and Performance of Vocal Communication Signals in the Bengalese Finch (Lonchura striata var. domestica)

    Science.gov (United States)

    Toccalino, Danielle C.; Sun, Herie; Sakata, Jon T.

    2016-01-01

    Cognitive processes like the formation of social memories can shape the nature of social interactions between conspecifics. Male songbirds use vocal signals during courtship interactions with females, but the degree to which social memory and familiarity influences the likelihood and structure of male courtship song remains largely unknown. Using a habituation-dishabituation paradigm, we found that a single, brief (female led to the formation of a short-term memory for that female: adult male Bengalese finches were significantly less likely to produce courtship song to an individual female when re-exposed to her 5 min later (i.e., habituation). Familiarity also rapidly decreased the duration of courtship songs but did not affect other measures of song performance (e.g., song tempo and the stereotypy of syllable structure and sequencing). Consistent with a contribution of social memory to the decrease in courtship song with repeated exposures to the same female, the likelihood that male Bengalese finches produced courtship song increased when they were exposed to a different female (i.e., dishabituation). Three consecutive exposures to individual females also led to the formation of a longer-term memory that persisted over days. Specifically, when courtship song production was assessed 2 days after initial exposures to females, males produced fewer and shorter courtship songs to familiar females than to unfamiliar females. Measures of song performance, however, were not different between courtship songs produced to familiar and unfamiliar females. The formation of a longer-term memory for individual females seemed to require at least three exposures because males did not differentially produce courtship song to unfamiliar females and females that they had been exposed to only once or twice. Taken together, these data indicate that brief exposures to individual females led to the rapid formation and persistence of social memories and support the existence of distinct

  16. Intracellular calcium chelation and pharmacological SERCA inhibition of Ca2+ pump in the insular cortex differentially affect taste aversive memory formation and retrieval.

    Science.gov (United States)

    Miranda, María Isabel; González-Cedillo, Francisco J; Díaz-Muñoz, Mauricio

    2011-09-01

    Variation in intracellular calcium concentration regulates the induction of long-term synaptic plasticity and is associated with a variety of memory/retrieval and learning paradigms. Accordingly, impaired calcium mobilization from internal deposits affects synaptic plasticity and cognition in the aged brain. During taste memory formation several proteins are modulated directly or indirectly by calcium, and recent evidence suggests the importance of calcium buffering and the role of intracellular calcium deposits during cognitive processes. Thus, the main goal of this research was to study the consequence of hampering changes in cytoplasmic calcium and inhibiting SERCA activity by BAPTA-AM and thapsigargin treatments, respectively, in the insular cortex during different stages of taste memory formation. Using conditioned taste aversion (CTA), we found differential effects of BAPTA-AM and thapsigargin infusions before and after gustatory stimulation, as well as during taste aversive memory consolidation; BAPTA-AM, but not thapsigargin, attenuates acquisition and/or consolidation of CTA, but neither compound affects taste aversive memory retrieval. These results point to the importance of intracellular calcium dynamics in the insular cortex during different stages of taste aversive memory formation. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Facilitating participation

    DEFF Research Database (Denmark)

    Skøtt, Bo

    2018-01-01

    the resulting need for a redefinition of library competence. In doing this, I primarily address the first two questions from Chapter 1 and how they relate to the public’s informal, leisure-time activities in a networked society. In particular, I focus on the skills of reflexive self-perception and informed...... opinion formation. Further, I point out the significance which these informal leisure-time activities have for public library staff’s cultural dissemination skills. In this way, I take on the question of the skills required for facilitating the learning of a participatory public (cf. Chapter 1......), exemplifying with the competence required of library staff. My discussion will proceed by way of a literature review. In the next section, I shall explain how and what sources were chosen and section three and four present the theoretical framework and how the applied theories are related. In the fifth section...

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

    Directory of Open Access Journals (Sweden)

    Agustina eFalibene

    2015-04-01

    Full Text Available 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 (MB 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.

  19. RNG105/caprin1, an RNA granule protein for dendritic mRNA localization, is essential for long-term memory formation.

    Science.gov (United States)

    Nakayama, Kei; Ohashi, Rie; Shinoda, Yo; Yamazaki, Maya; Abe, Manabu; Fujikawa, Akihiro; Shigenobu, Shuji; Futatsugi, Akira; Noda, Masaharu; Mikoshiba, Katsuhiko; Furuichi, Teiichi; Sakimura, Kenji; Shiina, Nobuyuki

    2017-11-21

    Local regulation of synaptic efficacy is thought to be important for proper networking of neurons and memory formation. Dysregulation of global translation influences long-term memory in mice, but the relevance of the regulation specific for local translation by RNA granules remains elusive. Here, we demonstrate roles of RNG105/caprin1 in long-term memory formation. RNG105 deletion in mice impaired synaptic strength and structural plasticity in hippocampal neurons. Furthermore, RNG105-deficient mice displayed unprecedentedly severe defects in long-term memory formation in spatial and contextual learning tasks. Genome-wide profiling of mRNA distribution in the hippocampus revealed an underlying mechanism: RNG105 deficiency impaired the asymmetric somato-dendritic localization of mRNAs. Particularly, RNG105 deficiency reduced the dendritic localization of mRNAs encoding regulators of AMPAR surface expression, which was consistent with attenuated homeostatic AMPAR scaling in dendrites and reduced synaptic strength. Thus, RNG105 has an essential role, as a key regulator of dendritic mRNA localization, in long-term memory formation.

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

    Science.gov (United States)

    Falibene, Agustina; Roces, Flavio; Rössler, Wolfgang

    2015-01-01

    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.

  1. Serotonin mediation of early memory formation via 5HT2B receptor-induced glycogenolysis in the day-old chick

    Directory of Open Access Journals (Sweden)

    Marie Elizabeth Gibbs

    2014-04-01

    Full Text Available Investigation of the effects of serotonin on memory formation in the chick revealed an action on at least two 5HT receptors. Serotonin injected intracerebrally produced a biphasic effect on memory consolidation with enhancement at low doses and inhibition at higher doses. The non-selective 5HT receptor antagonist methiothepin and the selective 5HT2B/C receptor antagonist SB221284 both inhibited memory, suggesting actions of serotonin on at least 2 different receptor subtypes. The 5HT2B/C and astrocyte-specific 5-HT receptor agonists, fluoxetine and paroxetine, enhanced memory and the effect was attributed to glycogenolysis. Inhibition of glycogenolysis with a low dose of DAB prevented both serotonin and fluoxetine from enhancing memory during short-term memory but not during intermediate memory. The role of serotonin on the 5HT2B/C receptor appears to involve glycogen breakdown in astrocytes during short-term memory, whereas other published evidence attributes the second period of glycogenolysis to noradrenaline.

  2. Rab5 Enhances Classical Swine Fever Virus Proliferation and Interacts with Viral NS4B Protein to Facilitate Formation of NS4B Related Complex

    Directory of Open Access Journals (Sweden)

    Jihui Lin

    2017-08-01

    Full Text Available Classical swine fever virus (CSFV is a fatal pig pestivirus and causes serious financial losses to the pig industry. CSFV NS4B protein is one of the most important viral replicase proteins. Rab5, a member of the small Rab GTPase family, is involved in infection and replication of numerous viruses including hepatitis C virus and dengue virus. Until now, the effects of Rab5 on the proliferation of CSFV are poorly defined. In the present study, we showed that Rab5 could enhance CSFV proliferation by utilizing lentivirus-mediated constitutive overexpression and eukaryotic plasmid transient overexpression approaches. On the other hand, lentivirus-mediated short hairpin RNA knockdown of Rab5 dramatically inhibited virus production. Co-immunoprecipitation, glutathione S-transferase pulldown and laser confocal microscopy assays further confirmed the interaction between Rab5 and CSFV NS4B protein. In addition, intracellular distribution of NS4B-Red presented many granular fluorescent signals (GFS in CSFV infected PK-15 cells. Inhibition of basal Rab5 function with Rab5 dominant negative mutant Rab5S34N resulted in disruption of the GFS. These results indicate that Rab5 plays a critical role in facilitating the formation of the NS4B related complexes. Furthermore, it was observed that NS4B co-localized with viral NS3 and NS5A proteins in the cytoplasm, suggesting that NS3 and NS5A might be components of the NS4B related complex. Taken together, these results demonstrate that Rab5 positively modulates CSFV propagation and interacts with NS4B protein to facilitate the NS4B related complexes formation.

  3. Revisiting the effect of reminders on infants' media memories: does the encoding format matter?

    Science.gov (United States)

    Barr, Rachel; Brito, Natalie; Simcock, Gabrielle

    2013-11-01

    With the present research, the authors examined whether reminders could maintain 18-month-olds' memories generated from picture books and videos. Infants (N = 98) were shown a series of target actions in a picture book or on video. Either 24 hr or 2 weeks prior to a 4-week deferred imitation test, they were exposed to a reminder, a partial presentation of the original media demonstration. After both reminder delays, groups that received a video demonstration and a video reminder (video/video) performed significantly better than did the video-reminder-only control group (x/video), but groups that received a picture-book demonstration and a picture-book reminder (book/book) did not perform better than did the picture-book-reminder-only control (x/book). Additionally, if reminders did not veridically match the conditions of encoding (e.g., video demonstration and a book reminder, video/book or vice versa), infants also failed to perform better than controls. Theoretical implications for the understanding of long-term memory processing during early childhood and practical implications for early multimedia usage are discussed.

  4. Negative polarity illusions and the format of hierarchical encodings in memory.

    Science.gov (United States)

    Parker, Dan; Phillips, Colin

    2016-12-01

    Linguistic illusions have provided valuable insights into how we mentally navigate complex representations in memory during language comprehension. Two notable cases involve illusory licensing of agreement and negative polarity items (NPIs), where comprehenders fleetingly accept sentences with unlicensed agreement or an unlicensed NPI, but judge those same sentences as unacceptable after more reflection. Existing accounts have argued that illusions are a consequence of faulty memory access processes, and make the additional assumption that the encoding of the sentence remains fixed over time. This paper challenges the predictions made by these accounts, which assume that illusions should generalize to a broader set of structural environments and a wider range of syntactic and semantic phenomena. We show across seven reading-time and acceptability judgment experiments that NPI illusions can be reliably switched "on" and "off", depending on the amount of time from when the potential licensor is processed until the NPI is encountered. But we also find that the same profile does not extend to agreement illusions. This contrast suggests that the mechanisms responsible for switching the NPI illusion on and off are not shared across all illusions. We argue that the contrast reflects changes over time in the encoding of the semantic/pragmatic representations that can license NPIs. Just as optical illusions have been informative about the visual system, selective linguistic illusions are informative not only about the nature of the access mechanisms, but also about the nature of the encoding mechanisms. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Social Memory Formation Rapidly and Differentially Affects the Motivation and Performance of Vocal Communication Signals in the Bengalese Finch (Lonchura striata var. domestica).

    Science.gov (United States)

    Toccalino, Danielle C; Sun, Herie; Sakata, Jon T

    2016-01-01

    Cognitive processes like the formation of social memories can shape the nature of social interactions between conspecifics. Male songbirds use vocal signals during courtship interactions with females, but the degree to which social memory and familiarity influences the likelihood and structure of male courtship song remains largely unknown. Using a habituation-dishabituation paradigm, we found that a single, brief (memory for that female: adult male Bengalese finches were significantly less likely to produce courtship song to an individual female when re-exposed to her 5 min later (i.e., habituation). Familiarity also rapidly decreased the duration of courtship songs but did not affect other measures of song performance (e.g., song tempo and the stereotypy of syllable structure and sequencing). Consistent with a contribution of social memory to the decrease in courtship song with repeated exposures to the same female, the likelihood that male Bengalese finches produced courtship song increased when they were exposed to a different female (i.e., dishabituation). Three consecutive exposures to individual females also led to the formation of a longer-term memory that persisted over days. Specifically, when courtship song production was assessed 2 days after initial exposures to females, males produced fewer and shorter courtship songs to familiar females than to unfamiliar females. Measures of song performance, however, were not different between courtship songs produced to familiar and unfamiliar females. The formation of a longer-term memory for individual females seemed to require at least three exposures because males did not differentially produce courtship song to unfamiliar females and females that they had been exposed to only once or twice. Taken together, these data indicate that brief exposures to individual females led to the rapid formation and persistence of social memories and support the existence of distinct mechanisms underlying the motivation to

  6. Formation of biodegradated polymers as components of future composite materials on the basis of shape memory alloy of medical appointment

    Science.gov (United States)

    Nasakina, E. O.; Baikin, A. S.; Sergiyenko, K. V.; Kaplan, M. A.; Konushkin, S. V.; Yakubov, A. D.; Izvin, A. V.; Sudarchikova, M. A.; Sevost’yanov, M. A.; Kolmakov, A. G.

    2018-04-01

    The processes of formation of polymer polylactide or polyglycylidactide films for the subsequent creation of a layered composite with a biodegradable layer on the basis of a nickel-free shape memory alloy TiNbTaZr are studied. The structure of the samples was determined using an SEM. The correspondence of morphology of surfaces of and the substrate itself is noted. High adhesion of the polymer to the future basis of the developed composite material is supposed. The formed films is homogeneous and amorphous throughout the polymer volume. By varying the volume of solutions, it is possible to obtain films of a given thickness for any type of polymer, its molecular weight, and the solution concentration of the polymer in chloroform. Poly (glycolide-lactide) should be more plastic than polylactide.

  7. Formation Process of Triangular Morphology of Self-Accommodation Martensite in Ti-Nb-Al Shape Memory Alloy

    Directory of Open Access Journals (Sweden)

    Kamioka Nozomi

    2015-01-01

    Full Text Available The formation process of a habit plane variant (HPV cluster with triangular morphology (T-cluster in Ti- Nb-Al shape memory alloy was investigated by in-situ optical microscopy. Upon cooling the specimen, martensitic transformation occurred and two types of V-shaped clusters and the T-clusters were observed. Two types of V-shaped cluster were the cluster connected by the {111} type I twin (VI and the cluster connected by the type II twin (VII. The T-cluster is formed by the connection of three HPVs by {111} type I twin. The T-cluster is formed by the growth of the third HPV that is nucleated at the tip of a HPV in a VI-cluster and exhibits inward growth. It is suggested that the T-cluster is a derivative of the VI-cluster. This growth behaviour is discussed based on the incompatibility of the clusters.

  8. Object formation in visual working memory: Evidence from object-based attention.

    Science.gov (United States)

    Zhou, Jifan; Zhang, Haihang; Ding, Xiaowei; Shui, Rende; Shen, Mowei

    2016-09-01

    We report on how visual working memory (VWM) forms intact perceptual representations of visual objects using sub-object elements. Specifically, when objects were divided into fragments and sequentially encoded into VWM, the fragments were involuntarily integrated into objects in VWM, as evidenced by the occurrence of both positive and negative object-based attention effects: In Experiment 1, when subjects' attention was cued to a location occupied by the VWM object, the target presented at the location of that object was perceived as occurring earlier than that presented at the location of a different object. In Experiment 2, responses to a target were significantly slower when a distractor was presented at the same location as the cued object (Experiment 2). These results suggest that object fragments can be integrated into objects within VWM in a manner similar to that of visual perception. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. “Okay ladies, now let’s get in formation!”: Music Videos and the Construction of Cultural Memory

    Directory of Open Access Journals (Sweden)

    Bertens Laura M. F.

    2017-08-01

    Full Text Available This paper explores strategies for constructing and perpetuating cultural memory through music videos, using Beyonce’s Formation (2016 and Janelle Monae’s Many Moons (2008 and Q.U.E.E.N. (2013 as case studies. The medium’s idiosyncrasies create unique ways of communicating and remembering, explored here within a framework of Cultural Studies and Memory Studies. Easy dissemination and the limited length of most videos ensure a large, diverse audience. The relative freedom from narrative constraints enables the director to create original imagery, and most importantly, the medium allows an intricate blending of performance and performativity; while the videos evidently are performances, they are strongly performative as well, not only with respect to gender and ethnicity but in significant ways also cultural memory. A close reading of Beyonce’s video Formation shows how she explicitly does the cultural memory of the New Orleans flooding. The videos by Monae are shown to produce counter-memories, relying heavily on the strategy of Afrofuturism. As such, these densely woven networks of visual symbols become palimpsests of black lived experience and cultural memory, passed on to millions of viewers.

  10. Neuroanatomy of episodic and semantic memory in humans: a brief review of neuroimaging studies.

    Science.gov (United States)

    García-Lázaro, Haydée G; Ramirez-Carmona, Rocio; Lara-Romero, Ruben; Roldan-Valadez, Ernesto

    2012-01-01

    One of the most basic functions in every individual and species is memory. Memory is the process by which information is saved as knowledge and retained for further use as needed. Learning is a neurobiological phenomenon by which we acquire certain information from the outside world and is a precursor to memory. Memory consists of the capacity to encode, store, consolidate, and retrieve information. Recently, memory has been defined as a network of connections whose function is primarily to facilitate the long-lasting persistence of learned environmental cues. In this review, we present a brief description of the current classifications of memory networks with a focus on episodic memory and its anatomical substrate. We also present a brief review of the anatomical basis of memory systems and the most commonly used neuroimaging methods to assess memory, illustrated with magnetic resonance imaging images depicting the hippocampus, temporal lobe, and hippocampal formation, which are the main brain structures participating in memory networks.

  11. Novel shifts in memory research and their impact on the legal process: introduction to the special issue on memory formation and suggestibility in the legal process.

    Science.gov (United States)

    Otgaar, Henry; Sauerland, Melanie; Petrila, John P

    2013-01-01

    The functioning and frailties of memory are frequently at the centerpiece of much expert testimony about the reliability of eyewitness accounts. Although we have much knowledge about how false memories and suggestibility can affect testimonies, the contributions in this special issue show that when using a sound theoretical framework, novel directions in this field can surface. The papers in this issue can broadly be divided into contributions that are related to: (1) the exact determinants of false memory and suggestibility; (2) new paradigms in legal psychology; (3) positive consequences of memory illusions; and (4) developmental false memory research. Collectively, these contributions have the potential to provide novel shifts in memory research and push this field beyond its current boundaries. Copyright © 2013 John Wiley & Sons, Ltd.

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

    Science.gov (United States)

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

    2006-01-01

    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…

  13. Addiction memory as a specific, individually learned memory imprint.

    Science.gov (United States)

    Böning, J

    2009-05-01

    The construct of "addiction memory" (AM) and its importance for relapse occurrence has been the subject of discussion for the past 30 years. Neurobiological findings from "social neuroscience" and biopsychological learning theory, in conjunction with construct-valid behavioral pharmacological animal models, can now also provide general confirmation of addiction memory as a pathomorphological correlate of addiction disorders. Under multifactorial influences, experience-driven neuronal learning and memory processes of emotional and cognitive processing patterns in the specific individual "set" and "setting" play an especially pivotal role in this connection. From a neuropsychological perspective, the episodic (biographical) memory, located at the highest hierarchical level, is of central importance for the formation of the AM in certain structural and functional areas of the brain and neuronal networks. Within this context, neuronal learning and conditioning processes take place more or less unconsciously and automatically in the preceding long-term-memory systems (in particular priming and perceptual memory). They then regulate the individually programmed addiction behavior implicitly and thus subsequently stand for facilitated recollection of corresponding, previously stored cues or context situations. This explains why it is so difficult to treat an addiction memory, which is embedded above all in the episodic memory, from the molecular carrier level via the neuronal pattern level through to the psychological meaning level, and has thus meanwhile become a component of personality.

  14. Two Parallel Pathways Assign Opposing Odor Valences during Drosophila Memory Formation

    Directory of Open Access Journals (Sweden)

    Daisuke Yamazaki

    2018-02-01

    Full Text Available During olfactory associative learning in Drosophila, odors activate specific subsets of intrinsic mushroom body (MB neurons. Coincident exposure to either rewards or punishments is thought to activate extrinsic dopaminergic neurons, which modulate synaptic connections between odor-encoding MB neurons and MB output neurons to alter behaviors. However, here we identify two classes of intrinsic MB γ neurons based on cAMP response element (CRE-dependent expression, γCRE-p and γCRE-n, which encode aversive and appetitive valences. γCRE-p and γCRE-n neurons act antagonistically to maintain neutral valences for neutral odors. Activation or inhibition of either cell type upsets this balance, toggling odor preferences to either positive or negative values. The mushroom body output neurons, MBON-γ5β′2a/β′2mp and MBON-γ2α′1, mediate the actions of γCRE-p and γCRE-n neurons. Our data indicate that MB neurons encode valence information, as well as odor information, and this information is integrated through a process involving MBONs to regulate learning and memory.

  15. The effects of enhanced zinc on spatial memory and plaque formation in transgenic mice

    Science.gov (United States)

    Linkous, D.H.; Adlard, P.A.; Wanschura, P.B.; Conko, K.M.; Flinn, J.M.

    2009-01-01

    There is considerable evidence suggesting that metals play a central role in the pathogenesis of Alzheimer's disease. Reports suggest that elevated dietary metals may both precipitate and potentiate an Alzheimer's disease phenotype. Despite this, there remain few studies that have examined the behavioral consequences of elevated dietary metals in wild type and Alzheimer's disease animals. To further investigate this in the current study, two separate transgenic models of AD (Tg2576 and TgCRND8), together with wild type littermates were administered 10 ppm (0.153 mM) Zn. Tg2576 animals were maintained on a zinc-enriched diet both pre- and postnatally until 11 months of age, while TgCRND8 animals were treated for five months following weaning. Behavioral testing, consisting of "Atlantis" and "moving" platform versions of the Morris water maze, were conducted at the end of the study, and tissues were collected for immunohistochemical analysis of amyloid-β burden. Our data demonstrate that the provision of a zinc-enriched diet potentiated Alzheimer-like spatial memory impairments in the transgenic animals and was associated with reduced hippocampal amyloid-β plaque deposits. Zinc-related behavioral deficits were also demonstrated in wild type mice, which were sometimes as great as those present in the transgenic animals. However, zinc-related cognitive impairments in transgenic mice were greater than the summation of zinc effects in the wild type mice and the transgene effects.

  16. A homolog of the vertebrate pituitary adenylate cyclase-activating polypeptide is both necessary and instructive for the rapid formation of associative memory in an invertebrate.

    Science.gov (United States)

    Pirger, Zsolt; László, Zita; Kemenes, Ildikó; Tóth, Gábor; Reglodi, Dóra; Kemenes, György

    2010-10-13

    Similar to other invertebrate and vertebrate animals, cAMP-dependent signaling cascades are key components of long-term memory (LTM) formation in the snail Lymnaea stagnalis, an established experimental model for studying evolutionarily conserved molecular mechanisms of long-term associative memory. Although a great deal is already known about the signaling cascades activated by cAMP, the molecules involved in the learning-induced activation of adenylate cyclase (AC) in Lymnaea remained unknown. Using matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy in combination with biochemical and immunohistochemical methods, recently we have obtained evidence for the existence of a Lymnaea homolog of the vertebrate pituitary adenylate cyclase-activating polypeptide (PACAP) and for the AC-activating effect of PACAP in the Lymnaea nervous system. Here we first tested the hypothesis that PACAP plays an important role in the formation of robust LTM after single-trial classical food-reward conditioning. Application of the PACAP receptor antagonist PACAP6-38 around the time of single-trial training with amyl acetate and sucrose blocked associative LTM, suggesting that in this "strong" food-reward conditioning paradigm the activation of AC by PACAP was necessary for LTM to form. We found that in a "weak" multitrial food-reward conditioning paradigm, lip touch paired with sucrose, memory formation was also dependent on PACAP. Significantly, systemic application of PACAP at the beginning of multitrial tactile conditioning accelerated the formation of transcription-dependent memory. Our findings provide the first evidence to show that in the same nervous system PACAP is both necessary and instructive for fast and robust memory formation after reward classical conditioning.

  17. Sucrose-induced analgesia during early life modulates adulthood learning and memory formation.

    Science.gov (United States)

    Nuseir, Khawla Q; Alzoubi, Karem H; Alabwaini, Jehad; Khabour, Omar F; Kassab, Manal I

    2015-06-01

    This study is aimed at examining the long-term effects of chronic pain during early life (postnatal day 0 to 8weeks), and intervention using sucrose, on cognitive functions during adulthood in rats. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution or paracetamol was administered for analgesia before the paw prick. Control groups include tactile stimulation to account for handling and touching the paws, and sucrose alone was used. All treatments were started on day one of birth and continued for 8weeks. At the end of the treatments, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM), as well as pain threshold via foot-withdrawal response to a hot plate apparatus. Additionally, the hippocampus was dissected, and blood was collected. Levels of neurotrophins (BDNF, IGF-1 and NT-3) and endorphins were assessed using ELISA. The results show that chronic noxious stimulation resulted in comparable foot-withdrawal latency between noxious and tactile groups. On the other hand, pretreatment with sucrose or paracetamol increased pain threshold significantly both in naive rats and noxiously stimulated rats (Pmemory, and sucrose treatment prevented such impairment (Pmemory impairment, and pretreatment with sucrose prevented this impairment via mechanisms that seem to involve BDNF. As evident in the results, sucrose, whether alone or in the presence of pre-noxious stimulation, increases pain threshold in such circumstances; most likely via a mechanism that involves an increase in endogenous opioids. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Emotion strengthens high-priority memory traces but weakens low-priority memory traces.

    Science.gov (United States)

    Sakaki, Michiko; Fryer, Kellie; Mather, Mara

    2014-02-01

    When people encounter emotional events, their memory for those events is typically enhanced. But it has been unclear how emotionally arousing events influence memory for preceding information. Does emotional arousal induce retrograde amnesia or retrograde enhancement? The current study revealed that this depends on the top-down goal relevance of the preceding information. Across three studies, we found that emotional arousal induced by one image facilitated memory for the preceding neutral item when people prioritized that neutral item. In contrast, an emotionally arousing image impaired memory for the preceding neutral item when people did not prioritize that neutral item. Emotional arousal elicited by both negative and positive pictures showed this pattern of enhancing or impairing memory for the preceding stimulus depending on its priority. These results indicate that emotional arousal amplifies the effects of top-down priority in memory formation.

  19. Influence of memory effect on the state-of-charge estimation of large-format Li-ion batteries based on LiFePO4 cathode

    Science.gov (United States)

    Shi, Wei; Wang, Jiulin; Zheng, Jianming; Jiang, Jiuchun; Viswanathan, Vilayanur; Zhang, Ji-Guang

    2016-04-01

    In this work, we systematically investigated the influence of the memory effect of LiFePO4 cathodes in large-format full batteries. The electrochemical performance of the electrodes used in these batteries was also investigated separately in half-cells to reveal their intrinsic properties. We noticed that the memory effect of LiFePO4/graphite cells depends not only on the maximum state of charge reached during the memory writing process, but is also affected by the depth of discharge reached during the memory writing process. In addition, the voltage deviation in a LiFePO4/graphite full battery is more complex than in a LiFePO4/Li half-cell, especially for a large-format battery, which exhibits a significant current variation in the region near its terminals. Therefore, the memory effect should be taken into account in advanced battery management systems to further extend the long-term cycling stabilities of Li-ion batteries using LiFePO4 cathodes.

  20. Membrane microdomains and the cytoskeleton constrain AtHIR1 dynamics and facilitate the formation of an AtHIR1-associated immune complex.

    Science.gov (United States)

    Lv, Xueqin; Jing, Yanping; Xiao, Jianwei; Zhang, Yongdeng; Zhu, Yingfang; Julian, Russell; Lin, Jinxing

    2017-04-01

    Arabidopsis hypersensitive-induced reaction (AtHIR) proteins function in plant innate immunity. However, the underlying mechanisms by which AtHIRs participate in plant immunity remain elusive. Here, using VA-TIRFM and FLIM-FRET, we revealed that AtHIR1 is present in membrane microdomains and co-localizes with the membrane microdomain marker REM1.3. Single-particle tracking analysis revealed that membrane microdomains and the cytoskeleton, especially microtubules, restrict the lateral mobility of AtHIR1 at the plasma membrane and facilitate its oligomerization. Furthermore, protein proximity index measurements, fluorescence cross-correlation spectroscopy, and biochemical experiments demonstrated that the formation of the AtHIR1 complex upon pathogen perception requires intact microdomains and cytoskeleton. Taken together, these findings suggest that microdomains and the cytoskeleton constrain AtHIR1 dynamics, promote AtHIR1 oligomerization, and increase the efficiency of the interactions of AtHIR1 with components of the AtHIR1 complex in response to pathogens, thus providing valuable insight into the mechanisms of defense-related responses in plants. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  1. H3K9me3 demethylase Kdm4d facilitates the formation of pre-initiative complex and regulates DNA replication.

    Science.gov (United States)

    Wu, Rentian; Wang, Zhiquan; Zhang, Honglian; Gan, Haiyun; Zhang, Zhiguo

    2017-01-09

    DNA replication is tightly regulated to occur once and only once per cell cycle. How chromatin, the physiological substrate of DNA replication machinery, regulates DNA replication remains largely unknown. Here we show that histone H3 lysine 9 demethylase Kdm4d regulates DNA replication in eukaryotic cells. Depletion of Kdm4d results in defects in DNA replication, which can be rescued by the expression of H3K9M, a histone H3 mutant transgene that reverses the effect of Kdm4d on H3K9 methylation. Kdm4d interacts with replication proteins, and its recruitment to DNA replication origins depends on the two pre-replicative complex components (origin recognition complex [ORC] and minichromosome maintenance [MCM] complex). Depletion of Kdm4d impairs the recruitment of Cdc45, proliferating cell nuclear antigen (PCNA), and polymerase δ, but not ORC and MCM proteins. These results demonstrate a novel mechanism by which Kdm4d regulates DNA replication by reducing the H3K9me3 level to facilitate formation of pre-initiative complex. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  2. Dynamic changes in neurexins' alternative splicing: role of Rho-associated protein kinases and relevance to memory formation.

    Directory of Open Access Journals (Sweden)

    Gabriela Rozic

    Full Text Available The three neurexins genes (NRXN1/2/3 encode polymorphic synaptic membrane proteins that are involved in cognitive functioning. Neurexins' selectivity of function is presumably conferred through differential use of 2 promoters and 5 alternative splicing sites (SS#1/2/3/4/5. In day-old rat brain neurons grown in culture, activation (depolarization induces reversible, calcium dependent, repression of NRXN2α SS#3 insert. The effects of depolarization on NRXN1/2/3α splicing and biochemical pathways mediating them were further studied in these neurons. NRXN1/2/3α splicing in the course of memory formation in vivo was also explored, using fear conditioning paradigm in rats in which the animals were trained to associate an aversive stimulus (electrical shock with a neutral context (a tone, resulting in the expression of fear responses to the neutral context.In the cultured neurons depolarization induced, beside NRXN2α SS#3, repression of SS#3 and SS#4 exons in NRXN3α but not NRXN1α. The repressions were mediated by the calcium/protein kinase C/Rho-associated protein kinase (ROCK pathway. Fear conditioning induced significant and transient repressions of the NRXN1/2/3α SS#4 exons in the rat hippocampus. ROCK inhibition prior to training attenuated the behavioral fear response, the NRXN1/2/3α splicing repressions and subsequent recovery and the levels of excitatory (PSD95 and inhibitory (gephyrin synaptic proteins in the hippocampus. No such effects were observed in the prefrontal cortex. Significant correlations existed between the fear response and hippocampal NRXN3α and NRXN2α SS#4 inserts as well as PSD95 protein levels. Hippocampal NRXN1α SS#4 insert and gephyrin levels did not correlate with the behavioral response but were negatively correlated with each other.These results show for the first time dynamic, experience related changes in NRXN1/2/3α alternative splicing in the rat brain and a role for ROCK in them. Specific neurexins

  3. Npas4 Is a Critical Regulator of Learning-Induced Plasticity at Mossy Fiber-CA3 Synapses during Contextual Memory Formation.

    Science.gov (United States)

    Weng, Feng-Ju; Garcia, Rodrigo I; Lutzu, Stefano; Alviña, Karina; Zhang, Yuxiang; Dushko, Margaret; Ku, Taeyun; Zemoura, Khaled; Rich, David; Garcia-Dominguez, Dario; Hung, Matthew; Yelhekar, Tushar D; Sørensen, Andreas Toft; Xu, Weifeng; Chung, Kwanghun; Castillo, Pablo E; Lin, Yingxi

    2018-03-07

    Synaptic connections between hippocampal mossy fibers (MFs) and CA3 pyramidal neurons are essential for contextual memory encoding, but the molecular mechanisms regulating MF-CA3 synapses during memory formation and the exact nature of this regulation are poorly understood. Here we report that the activity-dependent transcription factor Npas4 selectively regulates the structure and strength of MF-CA3 synapses by restricting the number of their functional synaptic contacts without affecting the other synaptic inputs onto CA3 pyramidal neurons. Using an activity-dependent reporter, we identified CA3 pyramidal cells that were activated by contextual learning and found that MF inputs on these cells were selectively strengthened. Deletion of Npas4 prevented both contextual memory formation and this learning-induced synaptic modification. We further show that Npas4 regulates MF-CA3 synapses by controlling the expression of the polo-like kinase Plk2. Thus, Npas4 is a critical regulator of experience-dependent, structural, and functional plasticity at MF-CA3 synapses during contextual memory formation. Copyright © 2018 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2005-01-01

    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.

  5. Memories of Earth Formation in the Modern Mantle: W Isotopic Composition of Flood Basalt Lavas

    Science.gov (United States)

    Rizo Garza, H. L.; Walker, R. J.; Carlson, R.; Horan, M. F.; Mukhopadhyay, S.; Francis, D.; Jackson, M. G.

    2015-12-01

    Four and a half billion years of geologic activity has overprinted much of the direct evidence for processes involved in Earth's formation and its initial chemical differentiation. Xenon isotopic ratios [1] and 3He/22Ne ratios [2] suggest that heterogeneities formed during Earth's accretion have been preserved to the present time. New opportunities to learn about early Earth history have opened up with the development of analytical techniques that allow high precision analysis of short-lived isotopic systems. The Hf-W system (t½ = 8.9 Ma) is particularly valuable for studying events that occurred during the first ~50 Ma of Solar System history. Here we report new data for ~ 60 Ma Baffin Bay and ~ 120 Ma Ontong Java Plateau lava samples. Both are large igneous provinces that may have sampled a primitive, less degassed deep mantle reservoir that has remained isolated since shortly after Earth formation [3,4]. Three samples analyzed have 182W/184W ratios that are 10 to 48 ppm higher than our terrestrial standard. These excesses in 182W are the highest ever measured in terrestrial rocks, and may reflect 182W ingrowth in an early-formed high Hf/W mantle domain that was produced by magma ocean differentiation [5]. Long and short-lived Sm-Nd systematics in these samples, however, are inconsistent with this hypothesis. The 182W excessses could rather reflect the derivation of these lavas from a mantle reservoir that was isolated from late accretionary additions [6]. The chondritic initial Os isotopic compositions and highly siderophile element abundances of these samples, however, are inconsistent with this interpretation. Tungsten concentrations for the Baffin Bay and Ontong Java Plateau samples range from 23 ppb to 62 ppb, and are negatively correlated with their 182W/184W ratios. We propose that the source reservoirs for these flood basalts likely formed through Hf/W fractionation caused by core-forming events occuring over a protacted time interval during Earth

  6. Usage Record Format Recommendation

    CERN Document Server

    Nilsen, J.K.; Muller-Pfeerkorn, R

    2013-01-01

    For resources to be shared, sites must be able to exchange basic accounting and usage data in a common format. This document describes a common format which enables the exchange of basic accounting and usage data from different resources. This record format is intended to facilitate the sharing of usage information, particularly in the area of the accounting of jobs, computing, memory, storage and cloud usage but with a structure that allows an easy extension to other resources. This document describes the Usage Record components both in natural language form and annotated XML. This document does not address how these records should be used, nor does it attempt to dictate the format in which the accounting records are stored. Instead, it denes a common exchange format. Furthermore, nothing is said regarding the communication mechanisms employed to exchange the records, i.e. transport layer, framing, authentication, integrity, etc.

  7. Calcitonin gene-related peptide erases the fear memory and facilitates long-term potentiation in the central nucleus of the amygdala in rats.

    Science.gov (United States)

    Wu, Xin; Zhang, Jie-Ting; Liu, Jue; Yang, Si; Chen, Tao; Chen, Jian-Guo; Wang, Fang

    2015-11-01

    Calcitonin gene-related peptide (CGRP) is a 37 amino acid neuropeptide, which plays a critical role in the central nervous system. CGRP binds to G protein-coupled receptors, including CGRP1, which couples positively to adenylyl cyclase (AC) and protein kinase A (PKA) activation. CGRP and CGRP1 receptors are enriched in central nucleus of the amygdala (CeA), the main part of the amygdala, which regulates conditioned fear memories. Here, we reported the importance of CGRP and CGRP1 receptor for synaptic plasticity in the CeA and the extinction of fear memory in rats. Our electrophysiological and behavioral in vitro and in vivo results showed exogenous application of CGRP induced an immediate and lasting long-term potentiation in the basolateral nucleus of amygdala-CeA pathway, but not in the lateral nucleus of amygdala-CeA pathway, while bilateral intra-CeA infusion CGRP (0, 5, 13 and 21 μM/side) dose dependently enhanced fear memory extinction. The effects were blocked by CGRP1 receptor antagonist (CGRP8-37 ), N-methyl-d-aspartate receptors antagonist MK801 and PKA inhibitor H89. These results demonstrate that CGRP can lead to long-term potentiation of basolateral nucleus of amygdala-CeA pathway through a PKA-dependent postsynaptic mechanism that involved N-methyl-d-aspartate receptors and enhance the extinction of fear memory in rats. Together, the results strongly support a pivotal role of CGRP in the synaptic plasticity of CeA and extinction of fear memory. Calcitonin gene-related peptide (CGRP) plays an essential role in synaptic plasticity in the amygdala and fear memory. We found that CGRP-induced chemical long-term potentiation (LTP) in a dose-dependent way in the BLA-CeA (basolateral and central nucleus of amygdala, respectively) pathway and enhanced fear memory extinction in rats through a protein kinase A (PKA)-dependent postsynaptic mechanism that involved NMDA receptors. These results support a pivotal role of CGRP in amygdala. © 2015 International

  8. Self-stabilized discharge filament in plane-parallel barrier discharge configuration: formation, breakdown mechanism, and memory effects

    Science.gov (United States)

    Tschiersch, R.; Nemschokmichal, S.; Bogaczyk, M.; Meichsner, J.

    2017-10-01

    Single self-stabilized discharge filaments were investigated in the plane-parallel electrode configuration. The barrier discharge was operated inside a gap of 3 mm shielded by glass plates to both electrodes, using helium-nitrogen mixtures and a square-wave feeding voltage at a frequency of 2 kHz. The combined application of electrical measurements, ICCD camera imaging, optical emission spectroscopy and surface charge diagnostics via the electro-optic Pockels effect allowed the correlation of the discharge development in the volume and on the dielectric surfaces. The formation criteria and existence regimes were found by systematic variation of the nitrogen admixture to helium, the total pressure and the feeding voltage amplitude. Single self-stabilized discharge filaments can be operated over a wide parameter range, foremost, by significant reduction of the voltage amplitude after the operation in the microdischarge regime. Here, the outstanding importance of the surface charge memory effect on the long-term stability was pointed out by the recalculated spatio-temporally resolved gap voltage. The optical emission revealed discharge characteristics that are partially reminiscent of both the glow-like barrier discharge and the microdischarge regime, such as a Townsend pre-phase, a fast cathode-directed ionization front during the breakdown and radially propagating surface discharges during the afterglow.

  9. Lead facilitates foci formation in a Balb/c-3T3 two-step cell transformation model: role of Ape1 function.

    Science.gov (United States)

    Hernández-Franco, Pablo; Silva, Martín; Franco, Rodrigo; Valverde, Mahara; Rojas, Emilio

    2018-04-01

    Several possible mechanisms have been examined to gain an understanding on the carcinogenic properties of lead, which include among others, mitogenesis, alteration of gene expression, oxidative damage, and inhibition of DNA repair. The aim of the present study was to explore if low concentrations of lead, relevant for human exposure, interfere with Ape1 function, a base excision repair enzyme, and its role in cell transformation in Balb/c-3T3. Lead acetate 5 and 30 μM induced APE1 mRNA and upregulation of protein expression. This increase in mRNA expression is consistent throughout the chronic exposure. Additionally, we also found an impaired function of Ape1 through molecular beacon-based assay. To evaluate the impact of lead on foci formation, a Balb/c-3T3 two-step transformation model was used. Balb/c-3T3 cells were pretreated 1 week with low concentrations of lead before induction of transformation with n-methyl-n-nitrosoguanidine (MNNG) (0.5 μg/mL) and 12-O-tetradecanoylphorbol-13-acetate (TPA) (0.1 μg/mL) (a classical two-step protocol). Morphological cell transformation increased in response to lead pretreatment that was paralleled with an increase in Ape1 mRNA and protein overexpression and an impairment of Ape1 activity and correlating with foci number. In addition, we found that lead pretreatment and MNNG (transformation initiator) increased DNA damage, determined by comet assay. Our data suggest that low lead concentrations (5, 30 μM) could play a facilitating role in cellular transformation, probably through the impaired function of housekeeping genes such as Ape1, leading to DNA damage accumulation and chromosomal instability, one of the most important hallmarks of cancer induced by chronic exposures.

  10. Negative affect impairs associative memory but not item memory.

    Science.gov (United States)

    Bisby, James A; Burgess, Neil

    2013-12-17

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 demonstrated that item memory was facilitated by emotional affect, whereas memory for an associated context was reduced. In Experiment 2, arousal was manipulated independently of the memoranda, by a threat of shock, whereby encoding trials occurred under conditions of threat or safety. Memory for context was equally impaired by the presence of negative affect, whether induced by threat of shock or a negative item, relative to retrieval of the context of a neutral item in safety. In Experiment 3, participants were presented with neutral and negative items as paired associates, including all combinations of neutral and negative items. The results showed both above effects: compared to a neutral item, memory for the associate of a negative item (a second item here, context in Experiments 1 and 2) is impaired, whereas retrieval of the item itself is enhanced. Our findings suggest that negative affect impairs associative memory while recognition of a negative item is enhanced. They support dual-processing models in which negative affect or stress impairs hippocampal-dependent associative memory while the storage of negative sensory/perceptual representations is spared or even strengthened.

  11. Identification of flap structure-specific endonuclease 1 as a factor involved in long-term memory formation of aversive learning.

    Science.gov (United States)

    Saavedra-Rodríguez, Lorena; Vázquez, Adrinel; Ortiz-Zuazaga, Humberto G; Chorna, Nataliya E; González, Fernando A; Andrés, Lissette; Rodríguez, Karen; Ramírez, Fernando; Rodríguez, Alan; Peña de Ortiz, Sandra

    2009-05-06

    We previously proposed that DNA recombination/repair processes play a role in memory formation. Here, we examined the possible role of the fen-1 gene, encoding a flap structure-specific endonuclease, in memory consolidation of conditioned taste aversion (CTA). Quantitative real-time PCR showed that amygdalar fen-1 mRNA induction was associated to the central processing of the illness experience related to CTA and to CTA itself, but not to the central processing resulting from the presentation of a novel flavor. CTA also increased expression of the Fen-1 protein in the amygdala, but not the insular cortex. In addition, double immunofluorescence analyses showed that amygdalar Fen-1 expression is mostly localized within neurons. Importantly, functional studies demonstrated that amygdalar antisense knockdown of fen-1 expression impaired consolidation, but not short-term memory, of CTA. Overall, these studies define the fen-1 endonuclease as a new DNA recombination/repair factor involved in the formation of long-term memories.

  12. Memory Dysfunction

    Science.gov (United States)

    Matthews, Brandy R.

    2015-01-01

    Purpose of Review: This article highlights the dissociable human memory systems of episodic, semantic, and procedural memory in the context of neurologic illnesses known to adversely affect specific neuroanatomic structures relevant to each memory system. Recent Findings: Advances in functional neuroimaging and refinement of neuropsychological and bedside assessment tools continue to support a model of multiple memory systems that are distinct yet complementary and to support the potential for one system to be engaged as a compensatory strategy when a counterpart system fails. Summary: Episodic memory, the ability to recall personal episodes, is the subtype of memory most often perceived as dysfunctional by patients and informants. Medial temporal lobe structures, especially the hippocampal formation and associated cortical and subcortical structures, are most often associated with episodic memory loss. Episodic memory dysfunction may present acutely, as in concussion; transiently, as in transient global amnesia (TGA); subacutely, as in thiamine deficiency; or chronically, as in Alzheimer disease. Semantic memory refers to acquired knowledge about the world. Anterior and inferior temporal lobe structures are most often associated with semantic memory loss. The semantic variant of primary progressive aphasia (svPPA) is the paradigmatic disorder resulting in predominant semantic memory dysfunction. Working memory, associated with frontal lobe function, is the active maintenance of information in the mind that can be potentially manipulated to complete goal-directed tasks. Procedural memory, the ability to learn skills that become automatic, involves the basal ganglia, cerebellum, and supplementary motor cortex. Parkinson disease and related disorders result in procedural memory deficits. Most memory concerns warrant bedside cognitive or neuropsychological evaluation and neuroimaging to assess for specific neuropathologies and guide treatment. PMID:26039844

  13. Differentially expressed genes linked to natural variation in long-term memory formation in Cotesia parasitic wasps

    NARCIS (Netherlands)

    Vugt, van J.J.F.A.; Hoedjes, K.M.; Geest, van de H.C.; Schijlen, E.G.W.M.; Vet, L.E.M.; Smid, H.M.

    2015-01-01

    Even though learning and memory are universal traits in the Animal Kingdom, closely related species reveal substantial variation in learning rate and memory dynamics. To determine the genetic background of this natural variation, we studied two congeneric parasitic wasp species, Cotesia glomerata

  14. Differentially expressed genes linked to natural variation in long-term memory formation in Cotesia parasitic wasps

    NARCIS (Netherlands)

    Van Vugt, Joke J. F. A.; Hoedjes, Katja M.; Van de Geest, Henri C.; Schijlen, Elio W. G. M.; Vet, Louise E. M.; Smid, Hans M.

    2015-01-01

    BACKGROUND: Even though learning and memory are universal traits in the Animal Kingdom, closely related species reveal substantial variation in learning rate and memory dynamics. To determine the genetic background of this natural variation, we studied two congeneric parasitic wasp species, Cotesia

  15. Stimulation of the noradrenergic system during memory formation impairs extinction learning but not the disruption of reconsolidation

    NARCIS (Netherlands)

    Soeter, M.; Kindt, M.

    2012-01-01

    The noradrenergic system plays a critical role in the ‘consolidation’ of emotional memory. If we are to target ‘reconsolidation’ in patients with anxiety disorders, the noradrenergic strengthening of fear memory should not impair the disruption of reconsolidation. In Experiment I, we addressed this

  16. Formation of two-way shape memory effect in rapid-quenched TiNiCu alloys

    International Nuclear Information System (INIS)

    Shelyakov, A.V.; Bykovsky, Yu.A.; Matveeva, N.M.; Kovneristy, Yu.K.

    1995-01-01

    Recently we have developed a number of devices for an optical radiation control based on the shape memory effect. A blind of rapid-quenched TiNiCu alloy having a two-way shape memory in bending was used as a basic element. So far as the rapid quenched alloy used is amorphous in initial state, it needs thermal annealing to form shape memory. This paper describes procedure of thermo-mechanical treatment, that allows to form desired two-way shape memory immediately during thermal annealing of amorphous alloy without training. It was shown that degree of two-way shape recovery depends critically on initial strain, temperature and duration of the annealing. It was experimentally determined optimum parameters of thermo-mechanical treatment to achieve maximum two-way shape memory. (orig.)

  17. Increasing Steps in Recall of Events: Factors Facilitating Immediate and Long-Term Memory in 13.5- and 16.5-Month-Old Children.

    Science.gov (United States)

    Bauer, Patricia J.; Hertsgaard, Louise A.

    1993-01-01

    Results of 3 experiments indicated that 13.5- and 16.5-month-old children recalled multiple sequences after a 1-week delay. Without cues, the recall of 16.5-month olds was facilitated by familiarity and by enabling relations; only enabling relations aided the 13.5-month olds' recall. With verbal cues, the recall of 13.5- and 16.5-month olds was…

  18. Facilitated stimulus-response associative learning and long-term memory in mice lacking the NTAN1 amidase of the N-end rule pathway.

    Science.gov (United States)

    Balogh, S A; McDowell, C S; Tae Kwon, Y; Denenberg, V H

    2001-02-23

    The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. Inactivation of the NTAN1 gene encoding the asparagine-specific N-terminal amidase in mice results in impaired spatial memory [26]. The studies described here were designed to further characterize the effects upon learning and memory of inactivating the NTAN1 gene. NTAN1-deficient mice were found to be better than wild-type mice on black-white and horizontal-vertical discrimination learning. They were also better at 8-week Morris maze retention testing when a reversal trial was not included in the testing procedures. In all three tasks NTAN1-deficient mice appeared to use a strong win-stay strategy. It is concluded that inactivating the asparagine-specific branch of the N-end rule pathway in mice results in impaired spatial learning with concomitant compensatory restructuring of the nervous system in favor of non-spatial (stimulus-response) learning.

  19. Acetylation-mediated suppression of transcription-independent memory: bidirectional modulation of memory by acetylation.

    Directory of Open Access Journals (Sweden)

    Katja Merschbaecher

    Full Text Available Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs, and the antagonistic histone deacetylases (HDACs play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM. While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact of both, increased and decreased acetylation on formation of appetitive olfactory memory in honeybees. We show that learning-induced changes in the acetylation of histone H3 at aminoacid-positions H3K9 and H3K18 exhibit distinct and different dynamics depending on the training strength. A strong training that induces LTM leads to an immediate increase in acetylation at H3K18 that stays elevated for hours. A weak training, not sufficient to trigger LTM, causes an initial increase in acetylation at H3K18, followed by a strong reduction in acetylation at H3K18 below the control group level. Acetylation at position H3K9 is not affected by associative conditioning, indicating specific learning-induced actions on the acetylation machinery. Elevating acetylation levels by blocking HDACs after conditioning leads to an improved memory. While memory after strong training is enhanced for at least 2 days, the enhancement after weak training is restricted to 1 day. Reducing acetylation levels by blocking HAT activity after strong training leads to a suppression of transcription-dependent LTM. The memory suppression is also observed in case of weak training, which does not require transcription processes. Thus, our findings demonstrate that acetylation-mediated processes act as bidirectional regulators of memory formation that facilitate or suppress memory independent of its transcription-requirement.

  20. Effects of hippocampal high-frequency electrical stimulation in memory formation and their association with amino acid tissue content and release in normal rats.

    Science.gov (United States)

    Luna-Munguía, Hiram; Meneses, Alfredo; Peña-Ortega, Fernando; Gaona, Andres; Rocha, Luisa

    2012-01-01

    Hippocampal high frequency electrical stimulation (HFS) at 130 Hz has been proposed as a therapeutical strategy to control neurological disorders such as intractable temporal lobe epilepsy (TLE). This study was carried out to determine the effects of hippocampal HFS on the memory process and the probable involvement of amino acids. Using the autoshaping task, we found that animals receiving hippocampal HFS showed augmented short-term, but not long-term memory formation, an effect blocked by bicuculline pretreatment and associated with enhanced tissue levels of amino acids in hippocampus. In addition, microdialysis experiments revealed high extracellular levels of glutamate, aspartate, glycine, taurine, and alanine during the application of hippocampal HFS. In contrast, GABA release augmented during HFS and remained elevated for more than 1 h after the stimulation was ended. HFS had minimal effects on glutamine release. The present results suggest that HFS has an activating effect on specific amino acids in normal hippocampus that may be involved in the enhanced short-term memory formation. These data further provide experimental support for the concept that hippocampus may be a promising target for focal stimulation to treat intractable seizures in humans. Copyright © 2010 Wiley Periodicals, Inc., Inc.

  1. Facilitators in Ambivalence

    Science.gov (United States)

    Karlsson, Mikael R.; Erlandson, Peter

    2018-01-01

    This is part of a larger ethnographical study concerning how school development in a local educational context sets cultural and social life in motion. The main data "in this article" consists of semi-structural interviews with teachers (facilitators) who have the responsibility of carrying out a project about formative assessment in…

  2. The facilitative effect of transcranial direct current stimulation on visuospatial working memory in patients with diabetic polyneuropathy: a pre-post sham-controlled study

    Directory of Open Access Journals (Sweden)

    YI-JEN WU

    2016-09-01

    Full Text Available Diabetes mellitus (DM can lead to diabetic polyneuropathy (DPN and cognitive deficits that manifest as peripheral and central neuropathy, respectively. In this study we investigated the relationship between visuospatial working memory (VSWM capacity and DPN severity, and attempted to improve VSWM in DPN patients via the use of transcranial direct current stimulation (tDCS. Sixteen DPN patients and sixteen age- and education-matched healthy control subjects received Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV and Montreal Cognitive Assessment (MOCA for baseline cognitive assessment. A forward- and backward-recall computerized Corsi block tapping task (CBT, both with and without a concurrent motor interference task was used to measure VSWM capacity. Each DPN patient underwent a pre-treatment CBT, followed by tDCS or sham treatment, then a post-treatment CBT on two separate days. We found that although patients with severe DPN (Dyck’s grade 2a or 2b showed comparable general intelligence scores on WAIS-IV as their age- and education-matched healthy counterparts, they nonetheless showed mild cognitive impairment on MOCA and working memory deficit on digit-span test of WAIS-IV. Furthermore, patients’ peripheral nerve conduction velocity (NCV was positively correlated with their VSWM span in the most difficult CBT condition that involved backward-recall with motor interference such that patients with worse NCV also had lower VSWM span. Most importantly, anodal tDCS over the right DLPFC was able to improve low-performing patients’ VSWM span to be on par with the high-performers, thereby eliminating the correlation between NCV and VSWM. In summary, these findings suggest that 1 mild cognitive impairment and severe peripheral neuropathy can coexist with unequal severity in diabetic patients, 2 the positive correlation of VSWM and NCV suggests a link between peripheral and central neuropathies and 3 anodal tDCS over the right DLPFC can

  3. Using Formative Assessment to Facilitate Learner Self-Regulation: A Case Study of Assessment Practices and Student Perceptions in Hong Kong

    Science.gov (United States)

    Jing Jing, Ma

    2017-01-01

    One of the key aims of formative assessment in higher education is to enable students to become self-regulated learners (Nicol & Macfarlane-Dick, 2006). Based on Nicol and Macfarlane-Dick's (2006) framework, this exploratory study investigates which formative assessment practices proposed by them were used by one college EFL writing teacher to…

  4. You can't stop the music: reduced auditory alpha power and coupling between auditory and memory regions facilitate the illusory perception of music during noise.

    Science.gov (United States)

    Müller, Nadia; Keil, Julian; Obleser, Jonas; Schulz, Hannah; Grunwald, Thomas; Bernays, René-Ludwig; Huppertz, Hans-Jürgen; Weisz, Nathan

    2013-10-01

    Our brain has the capacity of providing an experience of hearing even in the absence of auditory stimulation. This can be seen as illusory conscious perception. While increasing evidence postulates that conscious perception requires specific brain states that systematically relate to specific patterns of oscillatory activity, the relationship between auditory illusions and oscillatory activity remains mostly unexplained. To investigate this we recorded brain activity with magnetoencephalography and collected intracranial data from epilepsy patients while participants listened to familiar as well as unknown music that was partly replaced by sections of pink noise. We hypothesized that participants have a stronger experience of hearing music throughout noise when the noise sections are embedded in familiar compared to unfamiliar music. This was supported by the behavioral results showing that participants rated the perception of music during noise as stronger when noise was presented in a familiar context. Time-frequency data show that the illusory perception of music is associated with a decrease in auditory alpha power pointing to increased auditory cortex excitability. Furthermore, the right auditory cortex is concurrently synchronized with the medial temporal lobe, putatively mediating memory aspects associated with the music illusion. We thus assume that neuronal activity in the highly excitable auditory cortex is shaped through extensive communication between the auditory cortex and the medial temporal lobe, thereby generating the illusion of hearing music during noise. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Facilitation as a teaching strategy : experiences of facilitators

    Directory of Open Access Journals (Sweden)

    E Lekalakala-Mokgele

    2006-09-01

    Full Text Available Changes in nursing education involve the move from traditional teaching approaches that are teacher-centred to facilitation, a student centred approach. The studentcentred approach is based on a philosophy of teaching and learning that puts the learner on centre-stage. The aim of this study was to identify the challenges of facilitators of learning using facilitation as a teaching method and recommend strategies for their (facilitators development and support. A qualitative, explorative and contextual design was used. Four (4 universities in South Africa which utilize facilitation as a teaching/ learning process were identified and the facilitators were selected to be the sample of the study. The main question posed during in-depth group interviews was: How do you experience facilitation as a teaching/learning method?. Facilitators indicated different experiences and emotions when they first had to facilitate learning. All of them indicated that it was difficult to facilitate at the beginning as they were trained to lecture and that no format for facilitation was available. They experienced frustrations and anxieties as a result. The lack of knowledge of facilitation instilled fear in them. However they indicated that facilitation had many benefits for them and for the students. Amongst the ones mentioned were personal and professional growth. Challenges mentioned were the fear that they waste time and that they do not cover the content. It is therefore important that facilitation be included in the training of nurse educators.

  6. Dopamine D1 receptor stimulation modulates the formation and retrieval of novel object recognition memory: Role of the prelimbic cortex.

    Science.gov (United States)

    Pezze, Marie A; Marshall, Hayley J; Fone, Kevin C F; Cassaday, Helen J

    2015-11-01

    Previous studies have shown that dopamine D1 receptor antagonists impair novel object recognition memory but the effects of dopamine D1 receptor stimulation remain to be determined. This study investigated the effects of the selective dopamine D1 receptor agonist SKF81297 on acquisition and retrieval in the novel object recognition task in male Wistar rats. SKF81297 (0.4 and 0.8 mg/kg s.c.) given 15 min before the sampling phase impaired novel object recognition evaluated 10 min or 24 h later. The same treatments also reduced novel object recognition memory tested 24 h after the sampling phase and when given 15 min before the choice session. These data indicate that D1 receptor stimulation modulates both the encoding and retrieval of object recognition memory. Microinfusion of SKF81297 (0.025 or 0.05 μg/side) into the prelimbic sub-region of the medial prefrontal cortex (mPFC) in this case 10 min before the sampling phase also impaired novel object recognition memory, suggesting that the mPFC is one important site mediating the effects of D1 receptor stimulation on visual recognition memory. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Do you remember where sounds, pictures and words came from? The role of the stimulus format in object location memory.

    Science.gov (United States)

    Delogu, Franco; Lilla, Christopher C

    2017-11-01

    Contrasting results in visual and auditory spatial memory stimulate the debate over the role of sensory modality and attention in identity-to-location binding. We investigated the role of sensory modality in the incidental/deliberate encoding of the location of a sequence of items. In 4 separated blocks, 88 participants memorised sequences of environmental sounds, spoken words, pictures and written words, respectively. After memorisation, participants were asked to recognise old from new items in a new sequence of stimuli. They were also asked to indicate from which side of the screen (visual stimuli) or headphone channel (sounds) the old stimuli were presented in encoding. In the first block, participants were not aware of the spatial requirement while, in blocks 2, 3 and 4 they knew that their memory for item location was going to be tested. Results show significantly lower accuracy of object location memory for the auditory stimuli (environmental sounds and spoken words) than for images (pictures and written words). Awareness of spatial requirement did not influence localisation accuracy. We conclude that: (a) object location memory is more effective for visual objects; (b) object location is implicitly associated with item identity during encoding and (c) visual supremacy in spatial memory does not depend on the automaticity of object location binding.

  8. nalyot, a mutation of the Drosophila myb-related Adf1 transcription factor, disrupts synapse formation and olfactory memory.

    Science.gov (United States)

    DeZazzo, J; Sandstrom, D; de Belle, S; Velinzon, K; Smith, P; Grady, L; DelVecchio, M; Ramaswami, M; Tully, T

    2000-07-01

    nalyot (nal) is a novel olfactory memory mutant of Drosophila, encoding Adf1, a myb-related transcription factor. Following extended training sessions, Adf1 mutants show normal early memory but defective longterm memory. Adf1 shows widespread spatiotemporal expression, yet mutant alleles reveal no discernible disruptions in gross morphology of the nervous system. Studies at the larval neuromuscular junction, however, reveal a role for Adf1 in the modulation of synaptic growth-in contrast to the role established for dCREB2 in the control of synaptic function (Davis et al., 1996). These findings suggest that Adf1 and dCREB2 regulate distinct transcriptional cascades involved in terminal stages of synapse maturation. More generally, Adf1 provides a novel link between molecular mechanisms of developmental and behavioral plasticity.

  9. The mysteries of remote memory

    Science.gov (United States)

    2018-01-01

    Long-lasting memories form the basis of our identity as individuals and lie central in shaping future behaviours that guide survival. Surprisingly, however, our current knowledge of how such memories are stored in the brain and retrieved, as well as the dynamics of the circuits involved, remains scarce despite seminal technical and experimental breakthroughs in recent years. Traditionally, it has been proposed that, over time, information initially learnt in the hippocampus is stored in distributed cortical networks. This process—the standard theory of memory consolidation—would stabilize the newly encoded information into a lasting memory, become independent of the hippocampus, and remain essentially unmodifiable throughout the lifetime of the individual. In recent years, several pieces of evidence have started to challenge this view and indicate that long-lasting memories might already ab ovo be encoded, and subsequently stored in distributed cortical networks, akin to the multiple trace theory of memory consolidation. In this review, we summarize these recent findings and attempt to identify the biologically plausible mechanisms based on which a contextual memory becomes remote by integrating different levels of analysis: from neural circuits to cell ensembles across synaptic remodelling and epigenetic modifications. From these studies, remote memory formation and maintenance appear to occur through a multi-trace, dynamic and integrative cellular process ranging from the synapse to the nucleus, and represent an exciting field of research primed to change quickly as new experimental evidence emerges. This article is part of a discussion meeting issue ‘Of mice and mental health: facilitating dialogue between basic and clinical neuroscientists’. PMID:29352028

  10. The role of retrieval mode and retrieval orientation in retrieval practice: insights from comparing recognition memory testing formats and restudying.

    Science.gov (United States)

    Gao, Chuanji; Rosburg, Timm; Hou, Mingzhu; Li, Bingbing; Xiao, Xin; Guo, Chunyan

    2016-12-01

    The effectiveness of retrieval practice for aiding long-term memory, referred to as the testing effect, has been widely demonstrated. However, the specific neurocognitive mechanisms underlying this phenomenon remain unclear. In the present study, we sought to explore the role of pre-retrieval processes at initial testing on later recognition performance by using event-related potentials (ERPs). Subjects studied two lists of words (Chinese characters) and then performed a recognition task or a source memory task, or restudied the word lists. At the end of the experiment, subjects received a final recognition test based on the remember-know paradigm. Behaviorally, initial testing (active retrieval) enhanced memory retention relative to restudying (passive retrieval). The retrieval mode at initial testing was indexed by more positive-going ERPs for unstudied items in the active-retrieval tasks than in passive retrieval from 300 to 900 ms. Follow-up analyses showed that the magnitude of the early ERP retrieval mode effect (300-500 ms) was predictive of the behavioral testing effect later on. In addition, the ERPs for correctly rejected new items during initial testing differed between the two active-retrieval tasks from 500 to 900 ms, and this ERP retrieval orientation effect predicted differential behavioral testing gains between the two active-retrieval conditions. Our findings confirm that initial testing promotes later retrieval relative to restudying, and they further suggest that adopting pre-retrieval processing in the forms of retrieval mode and retrieval orientation might contribute to these memory enhancements.

  11. The formation of the two-way shape memory effect in rapidly quenched TiNiCu alloy under laser radiation

    International Nuclear Information System (INIS)

    Shelyakov, A V; Sitnikov, N N; Borodako, K A; Menushenkov, A P; Fominski, V Yu; Sheyfer, D V

    2015-01-01

    The effect of pulsed laser radiation (λ = 248 nm, τ = 20 ns) on structural properties and shape memory behavior of the rapidly quenched Ti 50 Ni 25 Cu 25 alloy ribbon was studied. The radiation energy density was varied from 2 to 20 mJ mm −2 . The samples were characterized by means of scanning electron microscopy, x-ray diffraction, microhardness measurements and shape memory bending tests. It was ascertained that the action of the laser radiation leads to the formation of a structural composite material due to amorphization or martensite modification in the surface layer of the ribbon. Two methods are proposed which allow one to generate the pronounced two-way shape memory effect (TWSME) in a local area of the ribbon by using only a single pulse of the laser radiation. With increasing energy density of laser treatment, the magnitude of the reversible angular displacement with realization of the TWSME increases. The developed techniques can be used for the creation of various micromechanical devices. (paper)

  12. Temporary formation of highly conducting domain walls for non-destructive read-out of ferroelectric domain-wall resistance switching memories

    Science.gov (United States)

    Jiang, Jun; Bai, Zi Long; Chen, Zhi Hui; He, Long; Zhang, David Wei; Zhang, Qing Hua; Shi, Jin An; Park, Min Hyuk; Scott, James F.; Hwang, Cheol Seong; Jiang, An Quan

    2018-01-01

    Erasable conductive domain walls in insulating ferroelectric thin films can be used for non-destructive electrical read-out of the polarization states in ferroelectric memories. Still, the domain-wall currents extracted by these devices have not yet reached the intensity and stability required to drive read-out circuits operating at high speeds. This study demonstrated non-destructive read-out of digital data stored using specific domain-wall configurations in epitaxial BiFeO3 thin films formed in mesa-geometry structures. Partially switched domains, which enable the formation of conductive walls during the read operation, spontaneously retract when the read voltage is removed, reducing the accumulation of mobile defects at the domain walls and potentially improving the device stability. Three-terminal memory devices produced 14 nA read currents at an operating voltage of 5 V, and operated up to T = 85 °C. The gap length can also be smaller than the film thickness, allowing the realization of ferroelectric memories with device dimensions far below 100 nm.

  13. [Effect of serotonin-modulated anticonsolidation protein on formation of long-term memory in carps Cyprinus carpio in the model of active avoidance learning].

    Science.gov (United States)

    Garina, D V; Mekhtiev, A A

    2014-01-01

    Effect of serotonin-modulated anticonsolidation protein (SMAP) that has property of disturbing formation of memory trace in mammals and of learning and memory in teleost fish was studied in the model of active avoidance learning. The experiment was performed in three stages: (1) fry of carps Cyprinus carpio L. was injected intracerebrovenricularly with the SMAP protein at a dose of 0.3 μg/g; control individuals were administered with equal amount of the buffered saline for poikilothermic animals; (2) 24 h after the injection, fish were learnt during 8 sèances for 2 days the conditioned reflex of active avoidance; (3) 48 h after the learning the testing of the skill was performed. The administration of the protein was shown to lead to disturbance of reproduction of the skill in the fish: the latent time of the skill reproduction in experimental individuals exceeded that in control fish more than two times, while the number of individuals succeeding the task in the experimental group was non-significantly lower than in the control group. However, unlike mammals, injection of the SMAP protein in this model produced no effect on the process of learning in carps. Thus, there was first demonstrated the inhibiting effect of the SMAP protein whose concentration correlated positively with the content of the neurotransmitter serotonin in brain on consolidation of memory traces in teleost fish.

  14. Memory formation for trace fear conditioning requires ubiquitin-proteasome mediated protein degradation in the prefrontal cortex.

    Directory of Open Access Journals (Sweden)

    David S Reis

    2013-10-01

    Full Text Available The cellular mechanisms supporting plasticity during memory consolidation have been a subject of considerable interest. De novo protein and mRNA synthesis in several brain areas are critical, and more recently protein degradation, mediated by the ubiquitin-proteasome system (UPS, has been shown to be important. Previous work clearly establishes a relationship between protein synthesis and protein degradation in the amygdala, but it is unclear whether cortical mechanisms of memory consolidation are similar to those in the amygdala. Recent work demonstrating a critical role for prefrontal cortex (PFC in the acquisition and consolidation of fear memory allows us to address this question. Here we use a PFC-dependent fear conditioning protocol to determine whether UPS mediated protein degradation is necessary for memory consolidation in PFC. Groups of rats were trained with auditory delay or trace fear conditioning and sacrificed 60 min after training. PFC tissue was then analyzed to quantify the amount of polyubiquinated protein. Other animals were trained with similar procedures but were infused with either a proteasome inhibitor (clasto-lactacystin β-lactone or a translation inhibitor (anisomycin in the PFC immediately after training. Our results show increased UPS-mediated protein degradation in the PFC following trace but not delay fear conditioning. Additionally, post-training proteasome or translation inhibition significantly impaired trace but not delay fear memory when tested the next day. Our results further support the idea that the PFC is critical for trace but not delay fear conditioning highlight the role of UPS-mediated degradation as critical for synaptic plasticity.

  15. Domain architecture of protein-disulfide isomerase facilitates its dual role as an oxidase and an isomerase in Ero1p-mediated disulfide formation

    DEFF Research Database (Denmark)

    Kulp, M. S.; Frickel, E. M.; Ellgaard, Lars

    2006-01-01

    reduction/rearrangement of non-native disulfides is poorly understood. We analyzed the role of individual PDI domains in disulfide bond formation in a reaction driven by their natural oxidant, Ero1p. We found that Ero1p oxidizes the isolated PDI catalytic thioredoxin domains, A and A' at the same rate......Native disulfide bond formation in eukaryotes is dependent on protein-disulfide isomerase (PDI) and its homologs, which contain varying combinations of catalytically active and inactive thioredoxin domains. However, the specific contribution of PDI to the formation of new disulfides versus...... catalytic (A) domain. The specific order of thioredoxin domains in PDI is important in establishing the asymmetry in the rate of oxidation of the two active sites thus allowing A and A', two thioredoxin domains that are similar in sequence and structure, to serve opposing functional roles as a disulfide...

  16. Facilitating Transfers

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    to specific logics of temporalisation and spatial expansion of a diverse set of social processes in relation to, for example, the economy, politics, science and the mass media. On this background, the paper will more concretely develop a conceptual framework for classifying different contextual orders...... that the essential functional and normative purpose of regulatory governance is to facilitate, stabilise and justify the transfer of condensed social components (such as economic capital and products, political decisions, legal judgements, religious beliefs and scientific knowledge) from one social contexts...

  17. Four-Week Strategy-Based Training to Enhance Prospective Memory in Older Adults: Targeting Intention Retention Is More Beneficial than Targeting Intention Formation.

    Science.gov (United States)

    Ihle, Andreas; Albiński, Rafal; Gurynowicz, Kamila; Kliegel, Matthias

    2018-01-01

    So far, training of prospective memory (PM) focused on very short instances (single sessions) and targeted the intention-formation phase only. We aimed to compare the effectiveness of 2 different 4-week strategy-based PM training types, namely imagery training (targeting the encoding of the PM intention in the intention-formation phase) versus rehearsal training (targeting the maintenance of the PM intention in the intention-retention phase) in older adults. We used a 4-week training protocol (8 sessions in total, 2 sessions per week). From the 44 participants, 21 were randomly assigned to the imagery training (vividly imagining a mental picture to memorize the connection between the PM cue words and related actions during intention formation) and 23 to the rehearsal training (rehearsing the PM cue words during intention retention). The criterion PM task was assessed before and after the training. Comparing the effectiveness of both training types, we found a significant time by training type interaction on PM accuracy in terms of PM cue detection, F(1, 42) = 6.07, p = 0.018, η2p = 0.13. Subsequent analyses revealed that the rehearsal training was more effective in enhancing PM accuracy in terms of PM cue detection than the imagery training. Strategy-based PM training in older adults targeting the maintenance of the PM intention in the intention-retention phase may be more effective in enhancing PM accuracy in terms of PM cue detection than the strategy targeting the encoding of the PM intention in the intention-formation phase. This suggests that for successful prospective remembering, older adults may need more support to keep the PM cues active in memory while working on the ongoing task than to initially encode the PM intention. © 2018 S. Karger AG, Basel.

  18. In Silico Analysis of Small RNAs Suggest Roles for Novel and Conserved miRNAs in the Formation of Epigenetic Memory in Somatic Embryos of Norway Spruce.

    Science.gov (United States)

    Yakovlev, Igor A; Fossdal, Carl G

    2017-01-01

    Epigenetic memory in Norway spruce affects the timing of bud burst and bud set, vitally important adaptive traits for this long-lived forest species. Epigenetic memory is established in response to the temperature conditions during embryogenesis. Somatic embryogenesis at different epitype inducing (EpI) temperatures closely mimics the natural processes of epigenetic memory formation in seeds, giving rise to epigenetically different clonal plants in a reproducible and predictable manner, with respect to altered bud phenology. MicroRNAs (miRNAs) and other small non-coding RNAs (sRNAs) play an essential role in the regulation of plant gene expression and may affect this epigenetic mechanism. We used NGS sequencing and computational in silico methods to identify and profile conserved and novel miRNAs among small RNAs in embryogenic tissues of Norway spruce at three EpI temperatures (18, 23 and 28°C). We detected three predominant classes of sRNAs related to a length of 24 nt, followed by a 21-22 nt class and a third 31 nt class of sRNAs. More than 2100 different miRNAs within the prevailing length 21-22 nt were identified. Profiling these putative miRNAs allowed identification of 1053 highly expressed miRNAs, including 523 conserved and 530 novels. 654 of these miRNAs were found to be differentially expressed (DEM) depending on EpI temperature. For most DEMs, we defined their putative mRNA targets. The targets represented mostly by transcripts of multiple-repeats proteins, like TIR, NBS-LRR, PPR and TPR repeat, Clathrin/VPS proteins, Myb-like, AP2, etc. Notably, 124 DE miRNAs targeted 203 differentially expressed epigenetic regulators. Developing Norway spruce embryos possess a more complex sRNA structure than that reported for somatic tissues. A variety of the predicted miRNAs showed distinct EpI temperature dependent expression patterns. These putative EpI miRNAs target spruce genes with a wide range of functions, including genes known to be involved in epigenetic

  19. In Silico Analysis of Small RNAs Suggest Roles for Novel and Conserved miRNAs in the Formation of Epigenetic Memory in Somatic Embryos of Norway Spruce

    Directory of Open Access Journals (Sweden)

    Igor A. Yakovlev

    2017-09-01

    Full Text Available Epigenetic memory in Norway spruce affects the timing of bud burst and bud set, vitally important adaptive traits for this long-lived forest species. Epigenetic memory is established in response to the temperature conditions during embryogenesis. Somatic embryogenesis at different epitype inducing (EpI temperatures closely mimics the natural processes of epigenetic memory formation in seeds, giving rise to epigenetically different clonal plants in a reproducible and predictable manner, with respect to altered bud phenology. MicroRNAs (miRNAs and other small non-coding RNAs (sRNAs play an essential role in the regulation of plant gene expression and may affect this epigenetic mechanism. We used NGS sequencing and computational in silico methods to identify and profile conserved and novel miRNAs among small RNAs in embryogenic tissues of Norway spruce at three EpI temperatures (18, 23 and 28°C. We detected three predominant classes of sRNAs related to a length of 24 nt, followed by a 21–22 nt class and a third 31 nt class of sRNAs. More than 2100 different miRNAs within the prevailing length 21–22 nt were identified. Profiling these putative miRNAs allowed identification of 1053 highly expressed miRNAs, including 523 conserved and 530 novels. 654 of these miRNAs were found to be differentially expressed (DEM depending on EpI temperature. For most DEMs, we defined their putative mRNA targets. The targets represented mostly by transcripts of multiple-repeats proteins, like TIR, NBS-LRR, PPR and TPR repeat, Clathrin/VPS proteins, Myb-like, AP2, etc. Notably, 124 DE miRNAs targeted 203 differentially expressed epigenetic regulators. Developing Norway spruce embryos possess a more complex sRNA structure than that reported for somatic tissues. A variety of the predicted miRNAs showed distinct EpI temperature dependent expression patterns. These putative EpI miRNAs target spruce genes with a wide range of functions, including genes known to be

  20. Nicotinic α7 and α4β2 agonists enhance the formation and retrieval of recognition memory: Potential mechanisms for cognitive performance enhancement in neurological and psychiatric disorders.

    Science.gov (United States)

    McLean, Samantha L; Grayson, Ben; Marsh, Samuel; Zarroug, Samah H O; Harte, Michael K; Neill, Jo C

    2016-04-01

    Cholinergic dysfunction has been shown to be central to the pathophysiology of Alzheimer's disease and has also been postulated to contribute to cognitive dysfunction observed in various psychiatric disorders, including schizophrenia. Deficits are found across a number of cognitive domains and in spite of several attempts to develop new therapies, these remain an unmet clinical need. In the current study we investigated the efficacy of donepezil, risperidone and selective nicotinic α7 and α4β2 receptor agonists to reverse a delay-induced deficit in recognition memory. Adult female Hooded Lister rats received drug treatments and were tested in the novel object recognition (NOR) task following a 6h inter-trial interval (ITI). In all treatment groups, there was no preference for the left or right identical objects in the acquisition trial. Risperidone failed to enhance recognition memory in this paradigm whereas donepezil was effective such that rats discriminated between the novel and familiar object in the retention trial following a 6h ITI. Although a narrow dose range of PNU-282987 and RJR-2403 was tested, only one dose of each increased recognition memory, the highest dose of PNU-282987 (10mg/kg) and the lowest dose of RJR-2403 (0.1mg/kg), indicative of enhanced cognitive performance. Interestingly, these compounds were also efficacious when administered either before the acquisition or the retention trial of the task, suggesting an important role for nicotinic receptor subtypes in the formation and retrieval of recognition memory. Copyright © 2016. Published by Elsevier B.V.

  1. Rapid-rate transcranial magnetic stimulation of animal auditory cortex impairs short-term but not long-term memory formation.

    Science.gov (United States)

    Wang, Hong; Wang, Xu; Wetzel, Wolfram; Scheich, Henning

    2006-04-01

    Bilateral rapid-rate transcranial magnetic stimulation (rTMS) of gerbil auditory cortex with a miniature coil device was used to study short-term and long-term effects on discrimination learning of frequency-modulated tones. We found previously that directional discrimination of frequency modulation (rising vs. falling) relies on auditory cortex processing and that formation of its memory depends on local protein synthesis. Here we show that, during training over 5 days, certain rTMS regimes contingent on training had differential effects on the time course of learning. When rTMS was applied several times per day, i.e. four blocks of 5 min rTMS each followed 5 min later by a 3-min training block and 15-min intervals between these blocks (experiment A), animals reached a high discrimination performance more slowly over 5 days than did controls. When rTMS preceded only the first two of four training blocks (experiment B), or when prolonged rTMS (20 min) preceded only the first block, or when blocks of experiment A had longer intervals (experiments C and D), no significant day-to-day effects were found. However, in experiment A, and to some extent in experiment B, rTMS reduced the within-session discrimination performance. Nevertheless the animals learned, as demonstrated by a higher performance the next day. Thus, our results indicate that rTMS treatments accumulate over a day but not strongly over successive days. We suggest that rTMS of sensory cortex, as used in our study, affects short-term memory but not long-term memory formation.

  2. Dnmts and Tet target memory-associated genes after appetitive olfactory training in honey bees.

    Science.gov (United States)

    Biergans, Stephanie D; Giovanni Galizia, C; Reinhard, Judith; Claudianos, Charles

    2015-11-04

    DNA methylation and demethylation are epigenetic mechanisms involved in memory formation. In honey bees DNA methyltransferase (Dnmt) function is necessary for long-term memory to be stimulus specific (i.e. to reduce generalization). So far, however, it remains elusive which genes are targeted and what the time-course of DNA methylation is during memory formation. Here, we analyse how DNA methylation affects memory retention, gene expression, and differential methylation in stimulus-specific olfactory long-term memory formation. Out of 30 memory-associated genes investigated here, 9 were upregulated following Dnmt inhibition in trained bees. These included Dnmt3 suggesting a negative feedback loop for DNA methylation. Within these genes also the DNA methylation pattern changed during the first 24 hours after training. Interestingly, this was accompanied by sequential activation of the DNA methylation machinery (i.e. Dnmts and Tet). In sum, memory formation involves a temporally complex epigenetic regulation of memory-associated genes that facilitates stimulus specific long-term memory in the honey bee.

  3. Serine/threonine-protein phosphatase 1 α levels are paralleling olfactory memory formation in the CD1 mouse.

    Science.gov (United States)

    Winding, Christiana; Sun, Yanwei; Höger, Harald; Bubna-Littitz, Hermann; Pollak, Arnold; Schmidt, Peter; Lubec, Gert

    2011-06-01

    Although olfactory discrimination has already been studied in several mouse strains, data on protein levels linked to olfactory memory are limited. Wild mouse strains Mus musculus musculus, Mus musculus domesticus and CD1 laboratory outbred mice were tested in a conditioned odor preference task and trained to discriminate between two odors, Rose and Lemon, by pairing one odor with a sugar reward. Six hours following the final test, mice were sacrificed and olfactory bulbs (OB) were taken for gel-based proteomics analyses and immunoblotting. OB proteins were extracted, separated by 2-DE and quantified using specific software (Proteomweaver). Odor-trained mice showed a preference for the previously rewarded odor suggesting that conditioned odor preference occurred. In CD1 mice levels, one out of 482 protein spots was significantly increased in odor-trained mice as compared with the control group; it was in-gel digested by trypsin and chymotrypsin and analyzed by tandem mass spectrometry (nano-ESI-LC-MS/MS). The spot was unambiguously identified as serine/threonine-protein phosphatase PP1-α catalytic subunit (PP-1A) and differential levels observed in gel-based proteomic studies were verified by immunoblotting. PP-1A is a key signalling element in synaptic plasticity and memory processes and is herein shown to be paralleling olfactory discrimination representing olfactory memory. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Characteristics of the stress-induced formation of R-phase in ultrafine-grained NiTi shape memory wire

    International Nuclear Information System (INIS)

    Olbricht, J.; Yawny, A.; Pelegrina, J.L.; Eggeler, G.; Yardley, V.A.

    2013-01-01

    Highlights: •We investigated the stress-induced formation of R-phase in NiTi shape memory wires. •The R-phase related strains were isolated from the overall stress-strain-behavior. •The stress–strain characteristics of R-phase suggest a homogeneous transformation. •Thermography confirms the homogeneous R-phase formation in ultrafine-grained NiTi. -- Abstract: The transformation between the cubic B2 and monoclinic B19′ phases in ultrafine-grained pseudoelastic NiTi can occur as a two-step process involving the intermediate rhombohedral R-phase. Experimental work using differential scanning calorimetry, electrical resistance measurements and transmission electron microscopy has demonstrated the formation of this intermediate phase during thermal cycling and during mechanical loading. In the present paper, complementary mechanical and thermographic results are presented which allow to further assess the character of the stress-induced R-phase formation. The transformation from B2 to R-phase is demonstrated to occur homogeneously within the gauge length rather than via advancing Lüders-type transition regions as it is the case in the localized transformation from B2 or R-phase to B19′

  5. Facilitating Transfers

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2018-01-01

    Departing from the paradox that globalisation has implied an increase, rather than a decrease, in contextual diversity, this paper re-assesses the function, normative purpose and location of Regulatory Governance Frameworks in world society. Drawing on insights from sociology of law and world...... society studies, the argument advanced is that Regulatory Governance Frameworks are oriented towards facilitating transfers of condensed social components, such as economic capital and products, legal acts, political decisions and scientific knowledge, from one legally-constituted normative order, i.......e. contextual setting, to another. Against this background, it is suggested that Regulatory Governance Frameworks can be understood as schemes which act as ‘rites of passage’ aimed at providing legal stabilisation to social processes characterised by liminality, i.e ambiguity, hybridity and in-betweenness....

  6. Multiferroic Memories

    Directory of Open Access Journals (Sweden)

    Amritendu Roy

    2012-01-01

    Full Text Available Multiferroism implies simultaneous presence of more than one ferroic characteristics such as coexistence of ferroelectric and magnetic ordering. This phenomenon has led to the development of various kinds of materials and conceptions of many novel applications such as development of a memory device utilizing the multifunctionality of the multiferroic materials leading to a multistate memory device with electrical writing and nondestructive magnetic reading operations. Though, interdependence of electrical- and magnetic-order parameters makes it difficult to accomplish the above and thus rendering the device to only two switchable states, recent research has shown that such problems can be circumvented by novel device designs such as formation of tunnel junction or by use of exchange bias. In this paper, we review the operational aspects of multiferroic memories as well as the materials used for these applications along with the designs that hold promise for the future memory devices.

  7. Deletion of epidermal Rac1 inhibits HPV-8 induced skin papilloma formation and facilitates HPV-8- and UV-light induced skin carcinogenesis.

    Science.gov (United States)

    Deshmukh, Jayesh; Pofahl, Ruth; Pfister, Herbert; Haase, Ingo

    2016-09-06

    Overexpression and increased activity of the small Rho GTPase Rac1 has been linked to squamous cell carcinoma of the epidermis and mucosa in humans. Targeted deletion of Rac1 or inhibition of Rac1 activity in epidermal keratinocytes reduced papilloma formation in a chemical skin carcinogenesis mouse model. However, a potential role of Rac1 in HPV- and UV-light induced skin carcinogenesis has not been investigated so far, solar UV radiation being an important carcinogen to the skin.To investigate this, we deleted Rac1 or modulated its activity in mice with transgenic expression of Human papilloma virus type-8 (HPV-8) in epidermal keratinocytes. Our data show that inhibition or deletion of Rac1 results in reduced papilloma formation upon UV-irradiation with a single dose, whereas constitutive activation of Rac1 strongly increases papilloma frequency in these mice. Surprisingly, we observed that, upon chronic UV-irradiation, the majority of mice with transgenic expression of HPV-8 and epidermis specific Rac1 deletion developed squamous cell carcinomas. Taken together, our data show that Rac1 exerts a dual role in skin carcinogenesis: its activation is, on one hand, required for HPV-8- and UV-light induced papilloma formation but, on the other, suppresses the development of squamous cell carcinomas.

  8. Slow oscillations orchestrating fast oscillations and memory consolidation.

    Science.gov (United States)

    Mölle, Matthias; Born, Jan

    2011-01-01

    Slow-wave sleep (SWS) facilitates the consolidation of hippocampus-dependent declarative memory. Based on the standard two-stage memory model, we propose that memory consolidation during SWS represents a process of system consolidation which is orchestrated by the neocortical memory. The slow oscillations temporally group neuronal activity into up-states of strongly enhanced neuronal activity and down-states of neuronal silence. In a feed-forward efferent action, this grouping is induced not only in the neocortex but also in other structures relevant to consolidation, namely the thalamus generating 10-15Hz spindles, and the hippocampus generating sharp wave-ripples, with the latter well known to accompany a replay of newly encoded memories taking place in hippocampal circuitries. The feed-forward synchronizing effect of the slow oscillation enables the formation of spindle-ripple events where ripples and accompanying reactivated hippocampal memory information become nested into the single troughs of spindles. Spindle-ripple events thus enable reactivated memory-related hippocampal information to be fed back to neocortical networks in the excitable slow oscillation up-state where they can induce enduring plastic synaptic changes underlying the effective formation of long-term memories. Copyright © 2011 Elsevier B.V. All rights reserved.

  9. Exposure to an enriched environment facilitates motor recovery and prevents short-term memory impairment and reduction of striatal BDNF in a progressive pharmacological model of parkinsonism in mice.

    Science.gov (United States)

    Campêlo, Clarissa L C; Santos, José R; Silva, Anatildes F; Dierschnabel, Aline L; Pontes, André; Cavalcante, Jeferson S; Ribeiro, Alessandra M; Silva, Regina H

    2017-06-15

    Previous studies showed that the repeated administration with a low dose of reserpine (RES) induces a gradual appearance of motor signs and cognitive deficits compatible with parkinsonism in rodents. Environmental stimulation has neuroprotective effects in animal models of neurodegenerative damage, including acutely induced parkinsonism. We investigated the effects of exposure to an enriched environment (EE) on motor, cognitive and neuronal (levels of tyrosine hydroxylase, TH and brain derived neurotrophic factor, BDNF) deficits induced by a progressive model of Parkinson's disease (PD) in mice. Male mice were repeatedly treated with vehicle or 0.1mg/kg of RES (s.c) and kept under two housing conditions: standard environment (SE) and EE. In animals kept in SE, the treatment with RES induced deficits in motor function (catalepsy test, open field and oral movements), in novel object recognition (NOR) and plus-maze discriminative avoidance tasks. The environmental stimulation facilitated the recovery of motor deficits assessed by the catalepsy test after the end of treatment. Additionally, exposure to EE prevented the memory deficit in the NOR task. Treatment with RES induced a reduction in the number of TH positive cells in SNpc and VTA, which recovered 30days after the end of treatment. Finally, RES reduced the levels of BDNF in the striatum and the exposure to the EE prevented this effect. These results suggest that plastic brain changes induced by EE promote beneficial effects on the progression of neuronal impairment related to PD. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. On the formation of an ultrafine-duplex structure facilitated by severe shear deformation in a Ti–20Mo β-type titanium alloy

    International Nuclear Information System (INIS)

    Xu, W.; Wu, X.; Stoica, M.; Calin, M.; Kühn, U.; Eckert, J.; Xia, K.

    2012-01-01

    Severe plastic deformation in the form of equal channel angular pressing (ECAP) has been adopted to introduce severe shear strain into a Ti–20 wt.% Mo β-type titanium alloy to elucidate the aging response of the severely deformed β matrix. Upon isothermal aging in the (α + β) phase field, selective heterogeneous α nucleation and growth resulted in a mixed precipitation microstructure. An ultrafine-duplex (α + β) structure composed of equiaxed α precipitates formed inside the shear bands (SBs) created during ECAP, whereas acicular α precipitates were favoured outside the SBs. This distinct precipitation structure has been correlated to the structural characteristics of the SBs: high disorder with dislocation cells characteristic of low-angle boundaries and enhanced atomic diffusivity. The highly disordered structure results in a weak variant selection and thereby promotes randomly orientated α precipitation without obeying the Burgers orientation relationship. Furthermore, the enhanced atomic diffusivity facilitates rapid growth of the α nuclei to form the ultrafine-duplex (α + β) structure.

  11. Early enriched environment exposure protects spatial memory and accelerates amyloid plaque formation