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Sample records for dependent memory consolidation

  1. Memory consolidation.

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    Squire, Larry R; Genzel, Lisa; Wixted, John T; Morris, Richard G

    2015-08-03

    Conscious memory for a new experience is initially dependent on information stored in both the hippocampus and neocortex. Systems consolidation is the process by which the hippocampus guides the reorganization of the information stored in the neocortex such that it eventually becomes independent of the hippocampus. Early evidence for systems consolidation was provided by studies of retrograde amnesia, which found that damage to the hippocampus-impaired memories formed in the recent past, but typically spared memories formed in the more remote past. Systems consolidation has been found to occur for both episodic and semantic memories and for both spatial and nonspatial memories, although empirical inconsistencies and theoretical disagreements remain about these issues. Recent work has begun to characterize the neural mechanisms that underlie the dialogue between the hippocampus and neocortex (e.g., "neural replay," which occurs during sharp wave ripple activity). New work has also identified variables, such as the amount of preexisting knowledge, that affect the rate of consolidation. The increasing use of molecular genetic tools (e.g., optogenetics) can be expected to further improve understanding of the neural mechanisms underlying consolidation. Copyright © 2015 Cold Spring Harbor Laboratory Press; all rights reserved.

  2. How aging affects sleep-dependent memory consolidation?

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    Caroline eHarand

    2012-02-01

    Full Text Available Sleep plays multiple functions among which energy conservation or recuperative processes. Besides, growing evidence indicate that sleep plays also a major role in memory consolidation, a process by which recently acquired and labile memory traces are progressively strengthened into more permanent and/or enhanced forms. Indeed, memories are not stored as they were initially encoded but rather undergo a gradual reorganization process, which is favoured by the neurochemical environment and the electrophysiological activity observed during sleep. Two putative, probably not exclusive, models (hippocampo-neocortical dialogue and synaptic homeostasis hypothesis have been proposed to explain the beneficial effect of sleep on memory processes. It is worth noting that all data gathered until now emerged from studies conducted in young subjects. The investigation of the relationships between sleep and memory in older adults has sparked off little interest until recently. Though, aging is characterized by memory impairment, changes in sleep architecture, as well as brain and neurochemical alterations. All these elements suggest that sleep-dependent memory consolidation may be impaired or occurs differently in older adults.Here, we give an overview of the mechanisms governing sleep-dependent memory consolidation, and the crucial points of this complex process that may dysfunction and result in impaired memory consolidation in aging.

  3. The Limited Capacity of Sleep-Dependent Memory Consolidation

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    Gordon B Feld

    2016-09-01

    Full Text Available Sleep supports memory consolidation. However, the conceptually important influence of the amount of items encoded in a memory test on this effect has not been investigated. In two experiments, participants (n=101 learned lists of word-pairs varying in length (40, 160, 320 word-pairs in the evening before a night of sleep (sleep group or of sleep deprivation (wake group. After 36 h (including a night allowing recovery sleep retrieval was tested. Compared with wakefulness, post-learning sleep enhanced retention for the 160 word-pair condition (p < 0.01, importantly, this effect completely vanished for the 320 word-pair condition. This result indicates a limited capacity for sleep-dependent memory consolidation, which is consistent with an active system consolidation view on sleep’s role for memory, if it is complemented by processes of active forgetting and/or gist abstraction. Whereas the absolute benefit from sleep should have increased with increasing amounts of successfully encoded items, if sleep only passively protected memory from interference. Moreover, the finding that retention performance was significantly diminished for the 320 word-pair condition compared to the 160 word-pair condition in the sleep group, makes it tempting to speculate that with increasing loads of information encoded during wakefulness, sleep might favour processes of forgetting over consolidation.

  4. New learning while consolidating memory during sleep is actively blocked by a protein synthesis dependent process

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    Levy, Roi; Levitan, David; Susswein, Abraham J

    2016-01-01

    Brief experiences while a memory is consolidated may capture the consolidation, perhaps producing a maladaptive memory, or may interrupt the consolidation. Since consolidation occurs during sleep, even fleeting experiences when animals are awakened may produce maladaptive long-term memory, or may interrupt consolidation. In a learning paradigm affecting Aplysia feeding, when animals were trained after being awakened from sleep, interactions between new experiences and consolidation were prevented by blocking long-term memory arising from the new experiences. Inhibiting protein synthesis eliminated the block and allowed even a brief, generally ineffective training to produce long-term memory. Memory formation depended on consolidative proteins already expressed before training. After effective training, long term memory required subsequent transcription and translation. Memory formation during the sleep phase was correlated with increased CREB1 transcription, but not CREB2 transcription. Increased C/EBP transcription was a correlate of both effective and ineffective training and of treatments not producing memory. DOI: http://dx.doi.org/10.7554/eLife.17769.001 PMID:27919318

  5. Schemas and memory consolidation.

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    Tse, Dorothy; Langston, Rosamund F; Kakeyama, Masaki; Bethus, Ingrid; Spooner, Patrick A; Wood, Emma R; Witter, Menno P; Morris, Richard G M

    2007-04-01

    Memory encoding occurs rapidly, but the consolidation of memory in the neocortex has long been held to be a more gradual process. We now report, however, that systems consolidation can occur extremely quickly if an associative "schema" into which new information is incorporated has previously been created. In experiments using a hippocampal-dependent paired-associate task for rats, the memory of flavor-place associations became persistent over time as a putative neocortical schema gradually developed. New traces, trained for only one trial, then became assimilated and rapidly hippocampal-independent. Schemas also played a causal role in the creation of lasting associative memory representations during one-trial learning. The concept of neocortical schemas may unite psychological accounts of knowledge structures with neurobiological theories of systems memory consolidation.

  6. Memory consolidation

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    Takashima, A.; Bakker, I.

    2016-01-01

    In order to make use of novel experiences and knowledge to guide our future behavior, we must keep large amounts of information accessible for retrieval. The memory system that stores this information needs to be flexible in order to rapidly incorporate incoming information, but also requires that

  7. Altered sleep composition after traumatic brain injury does not affect declarative sleep-dependent memory consolidation

    OpenAIRE

    Janna eMantua; Keenan M Mahan; Owen S Henry; Rebecca M. C. Spencer

    2015-01-01

    Individuals with a history of traumatic brain injury (TBI) often report sleep disturbances, which may be caused by changes in sleep architecture or reduced sleep quality (greater time awake after sleep onset, poorer sleep efficiency, and sleep stage proportion alterations). Sleep is beneficial for memory formation, and herein we examine whether altered sleep physiology following TBI has deleterious effects on sleep-dependent declarative memory consolidation. Participants learned a list of wor...

  8. Evidence for sleep-dependent memory consolidation in human and mice

    OpenAIRE

    Cai, Denise Jade

    2010-01-01

    Sleep has been implicated as playing an important role in memory consolidation. Considerable indirect evidence suggests a role for sleep in hippocampus-dependent memory in rodents. Hippocampal "place cells" that were active during maze running were more likely to be activated during subsequent sleep, a phenomenon known as neural replay. In addition to hippocampal neural replay, it has been asserted that the hippocampus and cortex communicate during sleep by means of hippocampal generated high...

  9. Sleep-mediated memory consolidation depends on the level of integration at encoding.

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    Himmer, Lea; Müller, Elias; Gais, Steffen; Schönauer, Monika

    2017-01-01

    There is robust evidence that sleep facilitates declarative memory consolidation. Integration of newly acquired memories into existing neocortical knowledge networks has been proposed to underlie this effect. Here, we test whether sleep affects memory retention for word-picture associations differently when it was learned explicitly or using a fast mapping strategy. Fast mapping is an incidental form of learning that references new information to existing knowledge and possibly allows neocortical integration already during encoding. If the integration of information into neocortical networks is a main function of sleep-dependent memory consolidation, material learned via fast mapping should therefore benefit less from sleep. Supporting this idea, we find that sleep has a protective effect on explicitly learned associations. In contrast, memory for associations learned by fast mapping does not benefit from sleep and remains stable regardless of whether sleep or wakefulness follows learning. Our results thus indicate that the need for sleep-mediated consolidation depends on the strategy used for learning and might thus be related to the level of integration of newly acquired memory achieved during encoding. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Sleep-dependent motor memory consolidation in older adults depends on task demands.

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    Gudberg, Christel; Wulff, Katharina; Johansen-Berg, Heidi

    2015-03-01

    It is often suggested that sleep-dependent consolidation of motor learning is impaired in older adults. The current study challenges this view and suggests that the degree of motor consolidation seen with sleep in older age groups depends on the kinematic demands of the task. We show that, when tested with a classic sequence learning task, requiring individuated finger movements, older adults did not show sleep-dependent consolidation. By contrast, when tested with an adapted sequence learning task, in which movements were performed with the whole hand, sleep-dependent motor improvement was observed in older adults. We suggest that age-related decline in fine motor dexterity may in part be responsible for the previously described deficit in sleep-dependent motor consolidation with aging.

  11. Untreated Sleep-Disordered Breathing: Links to Aging-Related Decline in Sleep-Dependent Memory Consolidation

    OpenAIRE

    Ina Djonlagic; Mengshuang Guo; Paul Matteis; Andrea Carusona; Robert Stickgold; Atul Malhotra

    2014-01-01

    Background: Increasing age is associated with a decline in cognition and motor skills, while at the same time exacerbating one's risk of developing obstructive sleep apnea (OSA). OSA-related cognitive deficits are highly prevalent and can affect various memory systems including overnight memory consolidation on a motor sequence task. Thus, the aim of our study was to examine the effect of aging on sleep-dependent motor memory consolidation in patients with and without OSA. Methods: We studied...

  12. Sleep-dependent memory consolidation of a new task is inhibited in psychiatric patients.

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    Genzel, Lisa; Ali, Elias; Dresler, Martin; Steiger, Axel; Tesfaye, Markos

    2011-04-01

    Schizophrenic and depressive patients show impeded sleep-dependent procedural memory consolidation. But this has been shown mainly for tasks testing the adaptation of old skills. This study tested the overnight memory consolidation of a new task and the transfer of this new skill to a similar task. Using an adapted version of the sequential finger tapping task, keyboard-naïve Ethiopian depressive (n = 8) and schizophrenic (n = 15) patients and healthy controls (n = 11 and n = 17) were tested twice, 24 h apart. In addition the subjects underwent training in a second sequence after the retest of the first sequence. Both schizophrenic and depressive patients did not show a significant overnight change in performance (1% and 4% improvement respectively) in the task and differed significantly from the healthy control groups who did show significant improvement (16% and 22%). Further in contrast to the healthy controls both patients groups showed no significant transfer of the newly acquired skill to the second sequence. This study shows that depressive and schizophrenic patients are not only deficient in the overnight memory consolidation of a new task, but also fail to show a transfer of this new skill to similar tasks.

  13. Sleep-Dependent Oscillatory Synchronization: A Role in Fear Memory Consolidation

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    Michael S. Totty

    2017-07-01

    Full Text Available Sleep plays an important role in memory consolidation through the facilitation of neuronal plasticity; however, how sleep accomplishes this remains to be completely understood. It has previously been demonstrated that neural oscillations are an intrinsic mechanism by which the brain precisely controls neural ensembles. Inter-regional synchronization of these oscillations is also known to facilitate long-range communication and long-term potentiation (LTP. In the present study, we investigated how the characteristic rhythms found in local field potentials (LFPs during non-REM and REM sleep play a role in emotional memory consolidation. Chronically implanted bipolar electrodes in the lateral amygdala (LA, dorsal and ventral hippocampus (DH, VH, and the infra-limbic (IL, and pre-limbic (PL prefrontal cortex were used to record LFPs across sleep-wake activity following each day of a Pavlovian cued fear conditioning paradigm. This resulted in three principle findings: (1 theta rhythms during REM sleep are highly synchronized between regions; (2 the extent of inter-regional synchronization during REM and non-REM sleep is altered by FC and EX; (3 the mean phase difference of synchronization between the LA and VH during REM sleep predicts changes in freezing after cued fear extinction. These results both oppose a currently proposed model of sleep-dependent memory consolidation and provide a novel finding which suggests that the role of REM sleep theta rhythms in memory consolidation may rely more on the relative phase-shift between neural oscillations, rather than the extent of phase synchronization.

  14. Altered sleep composition after traumatic brain injury does not affect declarative sleep-dependent memory consolidation.

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    Mantua, Janna; Mahan, Keenan M; Henry, Owen S; Spencer, Rebecca M C

    2015-01-01

    Individuals with a history of traumatic brain injury (TBI) often report sleep disturbances, which may be caused by changes in sleep architecture or reduced sleep quality (greater time awake after sleep onset, poorer sleep efficiency, and sleep stage proportion alterations). Sleep is beneficial for memory formation, and herein we examine whether altered sleep physiology following TBI has deleterious effects on sleep-dependent declarative memory consolidation. Participants learned a list of word pairs in the morning or evening, and recall was assessed 12-h later, following an interval awake or with overnight sleep. Young adult participants (18-22 years) were assigned to one of four experimental groups: TBI Sleep (n = 14), TBI Wake (n = 12), non-TBI Sleep (n = 15), non-TBI Wake (n = 15). Each TBI participant was >1 year post-injury. Sleep physiology was measured with polysomnography. Memory consolidation was assessed by comparing change in word-pair recall over 12-h intersession intervals. The TBI group spent a significantly greater proportion of the night in SWS than the non-TBI group at the expense of NREM1. The TBI group also had marginally lower EEG delta power during SWS in the central region. Intersession changes in recall were greater for intervals with sleep than without sleep in both groups. However, despite abnormal sleep stage proportions for individuals with a TBI history, there was no difference in the intersession change in recall following sleep for the TBI and non-TBI groups. In both Sleep groups combined, there was a positive correlation between Intersession Change and the proportion of the night in NREM2 + SWS. Overall, sleep composition is altered following TBI but such deficits do not yield insufficiencies in sleep-dependent memory consolidation.

  15. Altered sleep composition after traumatic brain injury does not affect declarative sleep-dependent memory consolidation

    Directory of Open Access Journals (Sweden)

    Janna eMantua

    2015-06-01

    Full Text Available Individuals with a history of traumatic brain injury (TBI often report sleep disturbances, which may be caused by changes in sleep architecture or reduced sleep quality (greater time awake after sleep onset, poorer sleep efficiency, and sleep stage proportion alterations. Sleep is beneficial for memory formation, and herein we examine whether altered sleep physiology following TBI has deleterious effects on sleep-dependent declarative memory consolidation. Participants learned a list of word pairs in the morning or evening, and recall was assessed 12-hrs later, following an interval awake or with overnight sleep. Young adult participants (18-22 yrs were assigned to one of four experimental groups: TBI Sleep (n=14, TBI Wake (n=12, non-TBI Sleep (n=15, non-TBI Wake (n=15. Each TBI participant was >1 yr post-injury. Sleep physiology was measured with polysomnography. Memory consolidation was assessed by comparing change in word-pair recall over 12-hr intersession intervals. The TBI group spent a significantly greater proportion of the night in SWS than the non-TBI group at the expense of NREM1. The TBI group also had marginally lower EEG delta power during SWS in the central region. Intersession changes in recall were greater for intervals with sleep than without sleep in both groups. However, despite abnormal sleep stage proportions for individuals with a TBI history, there was no difference in the intersession change in recall following sleep for the TBI and non-TBI groups. In both Sleep groups combined, there was a positive correlation between Intersession Change and the proportion of the night in NREM2 + SWS. Overall, sleep composition is altered following TBI but such deficits do not yield insufficiencies in sleep-dependent memory consolidation.

  16. Memory consolidation in human sleep depends on inhibition of glucocorticoid release.

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    Plihal, W; Born, J

    1999-09-09

    Early sleep dominated by slow-wave sleep has been found to be particularly relevant for declarative memory formation via hippocampo-neocortical networks. Concurrently, early nocturnal sleep is characterized by an inhibition of glucocorticoid release from the adrenals. Here, we show in healthy humans that this inhibition serves to support declarative memory consolidation during sleep. Elevating plasma glucocorticoid concentration during early sleep by administration of cortisol impaired consolidation of paired associate words, but not of non-declarative memory of visuomotor skills. Since glucocorticoid concentration was enhanced only during retention sleep, but not during acquisition or retrieval, a specific effect on the consolidation process is indicated. Blocking mineralocorticoid receptors by canrenoate did not affect memory, suggesting inactivation of glucocorticoid receptors to be the essential prerequisite for memory consolidation during early sleep.

  17. Estradiol-Induced Object Recognition Memory Consolidation Is Dependent on Activation of mTOR Signaling in the Dorsal Hippocampus

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    Fortress, Ashley M.; Fan, Lu; Orr, Patrick T.; Zhao, Zaorui; Frick, Karyn M.

    2013-01-01

    The mammalian target of rapamycin (mTOR) signaling pathway is an important regulator of protein synthesis and is essential for various forms of hippocampal memory. Here, we asked whether the enhancement of object recognition memory consolidation produced by dorsal hippocampal infusion of 17[Beta]-estradiol (E[subscript 2]) is dependent on mTOR…

  18. A dream model: Reactivation and re-encoding mechanisms for sleep-dependent memory consolidation

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    Kachergis, G.E.; Kleijn, R. de; Hommel, B.

    2016-01-01

    We humans spend almost a third of our lives asleep, and there is mounting evidence that sleep not only maintains, but actually improves many of our cognitive functions. Memory consolidation - the process of crystallizing and integrating memories into knowledge and skills - is particularly benefitted

  19. Entorhinal cortex and consolidated memory.

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    Takehara-Nishiuchi, Kaori

    2014-07-01

    The entorhinal cortex is thought to support rapid encoding of new associations by serving as an interface between the hippocampus and neocortical regions. Although the entorhinal-hippocampal interaction is undoubtedly essential for initial memory acquisition, the entorhinal cortex contributes to memory retrieval even after the hippocampus is no longer necessary. This suggests that during memory consolidation additional synaptic reinforcement may take place within the cortical network, which may change the connectivity of entorhinal cortex with cortical regions other than the hippocampus. Here, I outline behavioral and physiological findings which collectively suggest that memory consolidation involves the gradual strengthening of connection between the entorhinal cortex and the medial prefrontal/anterior cingulate cortex (mPFC/ACC), a region that may permanently store the learned association. This newly formed connection allows for close interaction between the entorhinal cortex and the mPFC/ACC, through which the mPFC/ACC gains access to neocortical regions that store the content of memory. Thus, the entorhinal cortex may serve as a gatekeeper of cortical memory network by selectively interacting either with the hippocampus or mPFC/ACC depending on the age of memory. This model provides a new framework for a modification of cortical memory network during systems consolidation, thereby adding a fresh dimension to future studies on its biological mechanism.

  20. Sleep-dependent memory consolidation in healthy aging and mild cognitive impairment.

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    Pace-Schott, Edward F; Spencer, Rebecca M C

    2015-01-01

    Sleep quality and architecture as well as sleep's homeostatic and circadian controls change with healthy aging. Changes include reductions in slow-wave sleep's (SWS) percent and spectral power in the sleep electroencephalogram (EEG), number and amplitude of sleep spindles, rapid eye movement (REM) density and the amplitude of circadian rhythms, as well as a phase advance (moved earlier in time) of the brain's circadian clock. With mild cognitive impairment (MCI) there are further reductions of sleep quality, SWS, spindles, and percent REM, all of which further diminish, along with a profound disruption of circadian rhythmicity, with the conversion to Alzheimer's disease (AD). Sleep disorders may represent risk factors for dementias (e.g., REM Behavior Disorder presages Parkinson's disease) and sleep disorders are themselves extremely prevalent in neurodegenerative diseases. Working memory , formation of new episodic memories, and processing speed all decline with healthy aging whereas semantic, recognition, and emotional declarative memory are spared. In MCI, episodic and working memory further decline along with declines in semantic memory. In young adults, sleep-dependent memory consolidation (SDC) is widely observed for both declarative and procedural memory tasks. However, with healthy aging, although SDC for declarative memory is preserved, certain procedural tasks, such as motor-sequence learning, do not show SDC. In younger adults, fragmentation of sleep can reduce SDC, and a normative increase in sleep fragmentation may account for reduced SDC with healthy aging. Whereas sleep disorders such as insomnia, obstructive sleep apnea, and narcolepsy can impair SDC in the absence of neurodegenerative changes, the incidence of sleep disorders increases both with normal aging and, further, with neurodegenerative disease. Specific features of sleep architecture, such as sleep spindles and SWS are strongly linked to SDC. Diminution of these features with healthy aging

  1. BDNF-dependent consolidation of fear memories in the perirhinal cortex

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    Brigitte eSchulz-Klaus

    2013-12-01

    Full Text Available In the recent years the perirhinal cortex (PRh has been identified as a crucial brain area in fear learning. Since the neurotrophin BDNF (brain-derived neurotrophic factor is an important mediator of synaptic plasticity and also crucially involved in memory consolidation of several learning paradigms, we analyzed now whether fear conditioning influences the expression of BDNF protein in the PRh. Here we observed a specific increase of BDNF protein 120 minutes after fear conditioning training. In order to test whether this increase of BDNF protein level is also required for the consolidation of the fear memory, we locally applied the Trk receptor inhibitor k252a into the PRh during this time window in a second series of experiments. By interfering with BDNF-TrkB-signaling during this critical time window, the formation of a long-term fear memory was completely blocked, indicated by a complete lack of fear potentiated startle one day later. In conclusion the present study further emphasizes the important role of the PRh in cued fear learning and identified BDNF as an important mediator for fear memory consolidation in the PRh.

  2. What drives sleep-dependent memory consolidation: greater gain or less loss?

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    Fenn, Kimberly M; Hambrick, David Z

    2013-06-01

    When memory is tested after a delay, performance is typically better if the retention interval includes sleep. However, it is unclear what accounts for this well-established effect. It is possible that sleep enhances the retrieval of information, but it is also possible that sleep protects against memory loss that normally occurs during waking activity. We developed a new research approach to investigate these possibilities. Participants learned a list of paired-associate items and were tested on the items after a 12-h interval that included waking or sleep. We analyzed the number of items gained versus the number of items lost across time. The sleep condition showed more items gained and fewer items lost than did the wake condition. Furthermore, the difference between the conditions (favoring sleep) in lost items was greater than the difference in gain, suggesting that loss prevention may primarily account for the effect of sleep on declarative memory consolidation. This finding may serve as an empirical constraint on theories of memory consolidation.

  3. Sleep-dependent synaptic down-selection (I): modeling the benefits of sleep on memory consolidation and integration.

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    Nere, Andrew; Hashmi, Atif; Cirelli, Chiara; Tononi, Giulio

    2013-01-01

    Sleep can favor the consolidation of both procedural and declarative memories, promote gist extraction, help the integration of new with old memories, and desaturate the ability to learn. It is often assumed that such beneficial effects are due to the reactivation of neural circuits in sleep to further strengthen the synapses modified during wake or transfer memories to different parts of the brain. A different possibility is that sleep may benefit memory not by further strengthening synapses, but rather by renormalizing synaptic strength to restore cellular homeostasis after net synaptic potentiation in wake. In this way, the sleep-dependent reactivation of neural circuits could result in the competitive down-selection of synapses that are activated infrequently and fit less well with the overall organization of memories. By using computer simulations, we show here that synaptic down-selection is in principle sufficient to explain the beneficial effects of sleep on the consolidation of procedural and declarative memories, on gist extraction, and on the integration of new with old memories, thereby addressing the plasticity-stability dilemma.

  4. Sleep-dependent memory consolidation is related to perceived value of learned material.

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    van Rijn, Elaine; Lucignoli, Carlo; Izura, Cristina; Blagrove, Mark T

    2017-06-01

    Although many types of newly encoded information can be consolidated during sleep, an enhanced effect has been found for memories tagged as relevant to the future, such as through knowledge of future testing or payment for successful recall. In the current study, participants (n = 80) learned Welsh and Breton translations of English words, and intrinsic relevance of learned material was operationalized as perceived value of the Welsh and Breton languages. Participants were non-Welsh native English speakers who had recently arrived in Wales. Memory for the words was tested immediately and 12 h later, after either a period of wake or a period of sleep. An increase in recall for both languages was found after sleep, but not after wake. Importantly, for the sleep condition, overnight improvement in Welsh word recall was associated with participants' level of valuing the Welsh language. This association was not found for the wake period condition. These findings support previous indications of an active role of sleep in the consolidation of memories relevant for the future, and demonstrate that this effect may be modulated by individual differences in perceived value of the learned material. It remains to be established whether this association is mediated by an emotional attachment to the language or a cognitive facility with it, or both. © 2016 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

  5. Memory consolidation in sleep disorders.

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    Cellini, Nicola

    2016-09-25

    In recent years sleep-related memory consolidation has become a central topic in the sleep research field. Several studies have shown that in healthy individuals sleep promotes memory consolidation. Notwithstanding this, the consequences of sleep disorders on offline memory consolidation remain poorly investigated. Research studies indicate that patients with insomnia, obstructive sleep apnea, and narcolepsy often exhibit sleep-related impairment in the consolidation of declarative and procedural information. On the other hand, patients with parasomnias, such as sleep-walking, night terrors and rapid eye movement (REM) behavior disorder, do not present any memory impairment. These studies suggest that only sleep disorders characterized by increased post-learning arousal and disrupted sleep architecture seem to be associated with offline memory consolidation issues. Such impairments, arising already in childhood, may potentially affect the development and maintenance of an individual's cognitive abilities, reducing their quality of life and increasing the risk of accidents. However, promising findings suggest that successfully treating sleep symptoms can result in the restoration of memory functions and marked reduction of direct and indirect societal costs of sleep disorders.

  6. Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation.

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    Lee, Michael L; Katsuyama, Ângela M; Duge, Leanne S; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J; de la Iglesia, Horacio O

    2016-11-01

    Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation.

  7. Two waves of proteasome-dependent protein degradation in the hippocampus are required for recognition memory consolidation.

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    Figueiredo, Luciana S; Dornelles, Arethuza S; Petry, Fernanda S; Falavigna, Lucio; Dargél, Vinicius A; Köbe, Luiza M; Aguzzoli, Cristiano; Roesler, Rafael; Schröder, Nadja

    2015-04-01

    Healthy neuronal function and synaptic modification require a concert of synthesis and degradation of proteins. Increasing evidence indicates that protein turnover mediated by proteasome activity is involved in long-term synaptic plasticity and memory. However, its role in different phases of memory remains debated, and previous studies have not examined the possible requirement of protein degradation in recognition memory. Here, we show that the proteasome inhibitor, lactacystin (LAC), infused into the CA1 area of the hippocampus at two specific time points during consolidation, impairs 24-retention of memory for object recognition in rats. Administration of LAC after retrieval did not affect retention. These findings provide the first evidence for a requirement of proteasome activity in recognition memory, indicate that protein degradation in the hippocampus is necessary during selective time windows of memory consolidation, and further our understanding of the role of protein turnover in memory formation. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Untreated sleep-disordered breathing: links to aging-related decline in sleep-dependent memory consolidation.

    Directory of Open Access Journals (Sweden)

    Ina Djonlagic

    Full Text Available BACKGROUND: Increasing age is associated with a decline in cognition and motor skills, while at the same time exacerbating one's risk of developing obstructive sleep apnea (OSA. OSA-related cognitive deficits are highly prevalent and can affect various memory systems including overnight memory consolidation on a motor sequence task. Thus, the aim of our study was to examine the effect of aging on sleep-dependent motor memory consolidation in patients with and without OSA. METHODS: We studied 44 patients (19-68 years who had been referred by a physician for a baseline polysomnography (PSG evaluation. Based on their PSG, patients were assigned either to the OSA group (AHI>5/h, or control (Non-OSA group (AHI<5/h. All subjects performed the Psychomotor Vigilance Task (PVT and the Motor Sequence Learning Task (MST in the evening and again in the morning after their PSG. RESULTS: Despite similar learning in the evening, OSA subjects showed significantly less overnight improvement on the MST, both for immediate (OSA -2.7% ± 2.8% vs. controls 12.2% ± 3.5%; p = 0.002 and plateau improvement (OSA 4.9% ± 2.3% vs. controls 21.1%± 4.0%; p = 0.001. Within the OSA group, there was a significant negative correlation between overnight MST improvement and age (r(2 = 0.3; p = 0.01, an effect that was not observed in the Non-OSA group (r(2 = 0.08; p = 0.23. CONCLUSIONS: Consistent with previous research, healthy sleepers demonstrated a higher degree of sleep-dependent overnight improvement on the MST, an effect not mitigated by increasing age. However, the presence of untreated obstructive sleep apnea is associated with an aging-related cognitive deficit, otherwise not present in individuals without OSA. As other research has linked the presence of OSA to a higher likelihood of developing dementia, future studies are necessary to examine if the inhibition of memory consolidation is tied to the onset of neurodegenerative disease.

  9. The dynamic nature of systems consolidation: Stress during learning as a switch guiding the rate of the hippocampal dependency and memory quality.

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    Pedraza, Lizeth K; Sierra, Rodrigo O; Boos, Flávia Z; Haubrich, Josué; Quillfeldt, Jorge A; Alvares, Lucas de Oliveira

    2016-03-01

    Memory fades over time, becoming more schematic or abstract. The loss of contextual detail in memory may reflect a time-dependent change in the brain structures supporting memory. It has been well established that contextual fear memory relies on the hippocampus for expression shortly after learning, but it becomes hippocampus-independent at a later time point, a process called systems consolidation. This time-dependent process correlates with the loss of memory precision. Here, we investigated whether training intensity predicts the gradual decay of hippocampal dependency to retrieve memory, and the quality of the contextual memory representation over time. We have found that training intensity modulates the progressive decay of hippocampal dependency and memory precision. Strong training intensity accelerates systems consolidation and memory generalization in a remarkable timeframe match. The mechanisms underpinning such process are triggered by glucocorticoid and noradrenaline released during training. These results suggest that the stress levels during emotional learning act as a switch, determining the fate of memory quality. Moderate stress will create a detailed memory, whereas a highly stressful training will develop a generic gist-like memory.

  10. Memory consolidation in the cerebellar cortex.

    Directory of Open Access Journals (Sweden)

    Daniel O Kellett

    Full Text Available Several forms of learning, including classical conditioning of the eyeblink, depend upon the cerebellum. In examining mechanisms of eyeblink conditioning in rabbits, reversible inactivations of the control circuitry have begun to dissociate aspects of cerebellar cortical and nuclear function in memory consolidation. It was previously shown that post-training cerebellar cortical, but not nuclear, inactivations with the GABAA agonist muscimol prevented consolidation but these findings left open the question as to how final memory storage was partitioned across cortical and nuclear levels. Memory consolidation might be essentially cortical and directly disturbed by actions of the muscimol, or it might be nuclear, and sensitive to the raised excitability of the nuclear neurons following the loss of cortical inhibition. To resolve this question, we simultaneously inactivated cerebellar cortical lobule HVI and the anterior interpositus nucleus of rabbits during the post-training period, so protecting the nuclei from disinhibitory effects of cortical inactivation. Consolidation was impaired by these simultaneous inactivations. Because direct application of muscimol to the nuclei alone has no impact upon consolidation, we can conclude that post-training, consolidation processes and memory storage for eyeblink conditioning have critical cerebellar cortical components. The findings are consistent with a recent model that suggests the distribution of learning-related plasticity across cortical and nuclear levels is task-dependent. There can be transfer to nuclear or brainstem levels for control of high-frequency responses but learning with lower frequency response components, such as in eyeblink conditioning, remains mainly dependent upon cortical memory storage.

  11. Sleep enhances memory consolidation in children.

    Science.gov (United States)

    Ashworth, Anna; Hill, Catherine M; Karmiloff-Smith, Annette; Dimitriou, Dagmara

    2014-06-01

    Sleep is an active state that plays an important role in the consolidation of memory. It has been found to enhance explicit memories in both adults and children. However, in contrast to adults, children do not always show a sleep-related improvement in implicit learning. The majority of research on sleep-dependent memory consolidation focuses on adults; hence, the current study examined sleep-related effects on two tasks in children. Thirty-three typically developing children aged 6-12 years took part in the study. Actigraphy was used to monitor sleep. Sleep-dependent memory consolidation was assessed using a novel non-word learning task and the Tower of Hanoi cognitive puzzle, which involves discovering an underlying rule to aid completion. Children were trained on the two tasks and retested following approximately equal retention intervals of both wake and sleep. After sleep, children showed significant improvements in performance of 14% on the non-word learning task and 25% on the Tower of Hanoi task, but no significant change in score following the wake retention interval. Improved performance on the Tower of Hanoi may have been due to children consolidating explicit aspects of the task, for example rule-learning or memory of previous sequences; thus, we propose that sleep is necessary for consolidation of explicit memory in children. Sleep quality and duration were not related to children's task performance. If such experimental sleep-related learning enhancement is generalizable to everyday life, then it is clear that sleep plays a vital role in children's educational attainment.

  12. A cellular mechanism for system memory consolidation

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    Michiel W. H. Remme

    2014-03-01

    Full Text Available Declarative memories initially depend on the hippocampus. Over a period of weeks to years, however, these memories become hippocampus-independent through a process called system memory consolidation. The underlying cellular mechanisms are unclear. Here, we suggest a consolidation mechanism, which is based on STDP and a ubiquitous anatomical network motif. As a first step in the memory consolidation process, we consider pyramidal neurons in the hippocampal CA1 area. These cells receive Schaffer collateral (SC input from the CA3 area at the proximal dendrites, and perforant path (PP input from entorhinal cortex at the distal dendrites. Both pathways carry sensory information that has been processed by cortical networks and that enters the hippocampus through the entorhinal cortex. Hence, information from entorhinal cortex reaches CA1 cells through an indirect pathway (via CA3 and SC and a direct pathway (PP. Memories are assumed to be initially stored in the recurrent CA3 network and the SC synapses during the awake, exploratory state. During a subsequent consolidation phase (during slow-wave sleep SC-dependent memories are partly transferred to the PP synapses. Through mathematical analysis and numerical simulations we show that this consolidation process occurs as a natural result from the combination of (1 STDP at PP synapses and (2 the temporal correlations between SC and PP activities, since the (indirect SC input is delayed compared to the (direct PP input by about 5-10 ms. With a detailed compartmental model we then show that the spatial tuning of a CA1 cell is copied from the proximal SC-synaptic inputs to the distal PP-inputs. Next, we repeated the network motif across many levels in a hierarchical network model: each direct connection at one level is part of the indirect pathway of the next level. Analysis and simulations of this hierarchical system demonstrate that memories gradually move from hippocampus into neocortex. Moreover, the

  13. Dysfunctional overnight memory consolidation in ecstasy users.

    Science.gov (United States)

    Smithies, Vanessa; Broadbear, Jillian; Verdejo-Garcia, Antonio; Conduit, Russell

    2014-08-01

    Sleep plays an important role in the consolidation and integration of memory in a process called overnight memory consolidation. Previous studies indicate that ecstasy users have marked and persistent neurocognitive and sleep-related impairments. We extend past research by examining overnight memory consolidation among regular ecstasy users (n=12) and drug naïve healthy controls (n=26). Memory recall of word pairs was evaluated before and after a period of sleep, with and without interference prior to testing. In addition, we assessed neurocognitive performances across tasks of learning, memory and executive functioning. Ecstasy users demonstrated impaired overnight memory consolidation, a finding that was more pronounced following associative interference. Additionally, ecstasy users demonstrated impairments on tasks recruiting frontostriatal and hippocampal neural circuitry, in the domains of proactive interference memory, long-term memory, encoding, working memory and complex planning. We suggest that ecstasy-associated dysfunction in fronto-temporal circuitry may underlie overnight consolidation memory impairments in regular ecstasy users.

  14. Nicotine facilitates memory consolidation in perceptual learning.

    Science.gov (United States)

    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'.

  15. System consolidation of memory during sleep.

    Science.gov (United States)

    Born, Jan; Wilhelm, Ines

    2012-03-01

    Over the past two decades, research has accumulated compelling evidence that sleep supports the formation of long-term memory. The standard two-stage memory model that has been originally elaborated for declarative memory assumes that new memories are transiently encoded into a temporary store (represented by the hippocampus in the declarative memory system) before they are gradually transferred into a long-term store (mainly represented by the neocortex), or are forgotten. Based on this model, we propose that sleep, as an offline mode of brain processing, serves the 'active system consolidation' of memory, i.e. the process in which newly encoded memory representations become redistributed to other neuron networks serving as long-term store. System consolidation takes place during slow-wave sleep (SWS) rather than rapid eye movement (REM) sleep. The concept of active system consolidation during sleep implicates that (a) memories are reactivated during sleep to be consolidated, (b) the consolidation process during sleep is selective inasmuch as it does not enhance every memory, and (c) memories, when transferred to the long-term store undergo qualitative changes. Experimental evidence for these three central implications is provided: It has been shown that reactivation of memories during SWS plays a causal role for consolidation, that sleep and specifically SWS consolidates preferentially memories with relevance for future plans, and that sleep produces qualitative changes in memory representations such that the extraction of explicit and conscious knowledge from implicitly learned materials is facilitated.

  16. D-Cycloserine Enhances Memory Consolidation of Hippocampus-Dependent Latent Extinction

    Science.gov (United States)

    Gabriele, Amanda; Packard, Mark G.

    2007-01-01

    Adult male Long-Evans rats were trained to run in a straight-alley maze for food reward and subsequently received hippocampus-dependent latent extinction training. Immediately following latent extinction, rats received peripheral injections of the NMDA receptor partial agonist D-cycloserine (DCS, 15 mg/kg), or saline. Twenty-four hours later, rats…

  17. The function of the sleep spindle: a physiological index of intelligence and a mechanism for sleep-dependent memory consolidation.

    Science.gov (United States)

    Fogel, Stuart M; Smith, Carlyle T

    2011-04-01

    Until recently, the electrophysiological mechanisms involved in strengthening new memories into a more permanent form during sleep have been largely unknown. The sleep spindle is an event in the electroencephalogram (EEG) characterizing Stage 2 sleep. Sleep spindles may reflect, at the electrophysiological level, an ideal mechanism for inducing long-term synaptic changes in the neocortex. Recent evidence suggests the spindle is highly correlated with tests of intellectual ability (e.g.; IQ tests) and may serve as a physiological index of intelligence. Further, spindles increase in number and duration in sleep following new learning and are correlated with performance improvements. Spindle density and sigma (14-16Hz) spectral power have been found to be positively correlated with performance following a daytime nap, and animal studies suggest the spindle is involved in a hippocampal-neocortical dialogue necessary for memory consolidation. The findings reviewed here collectively provide a compelling body of evidence that the function of the sleep spindle is related to intellectual ability and memory consolidation.

  18. Negative Reinforcement Impairs Overnight Memory Consolidation

    Science.gov (United States)

    Stamm, Andrew W.; Nguyen, Nam D.; Seicol, Benjamin J.; Fagan, Abigail; Oh, Angela; Drumm, Michael; Lundt, Maureen; Stickgold, Robert; Wamsley, Erin J.

    2014-01-01

    Post-learning sleep is beneficial for human memory. However, it may be that not all memories benefit equally from sleep. Here, we manipulated a spatial learning task using monetary reward and performance feedback, asking whether enhancing the salience of the task would augment overnight memory consolidation and alter its incorporation into…

  19. Exercise enhances memory consolidation in the aging brain

    Directory of Open Access Journals (Sweden)

    Shikha eSnigdha

    2014-02-01

    Full Text Available Exercise has been shown to reduce age-related losses in cognitive function including learning and memory, but the mechanisms underlying this effect remain poorly understood. Memory formation occurs in stages that include an initial acquisition phase, an intermediate labile phase, and then a process of consolidation which leads to long term memory formation. An effective way to examine the mechanism by which exercise improves memory is to introduce the intervention (exercise, post-acquisition, making it possible to selectively examine memory storage and consolidation. Accordingly we evaluated the effects of post-trial exercise (10 minutes on a treadmill on memory consolidation in aged canines both right after, an hour after, and twenty-four hours after acute exercise training in concurrent discrimination, object location memory (OLM and novel object recognition (NOR tasks. Our study shows that post-trial exercise facilitates memory function by improving memory consolidation in aged animals in a time-dependent manner. The improvements were significant at twenty-four hour post exercise and not right after or one hour after exercise. Aged animals were also tested following chronic exercise (10 min/day for 14 consecutive days on OLM or till criterion were reached (for reversal learning task. We found improvements from a chronic exercise design in both the object location and reversal learning tasks. Our studies suggest that mechanisms to improve overall consolidation and cognitive function remain accessible even with progressing age and can be re-engaged by both acute and chronic exercise.

  20. Exercise enhances memory consolidation in the aging brain.

    Science.gov (United States)

    Snigdha, Shikha; de Rivera, Christina; Milgram, Norton W; Cotman, Carl W

    2014-01-01

    Exercise has been shown to reduce age-related losses in cognitive function including learning and memory, but the mechanisms underlying this effect remain poorly understood. Memory formation occurs in stages that include an initial acquisition phase, an intermediate labile phase, and then a process of consolidation which leads to long-term memory formation. An effective way to examine the mechanism by which exercise improves memory is to introduce the intervention (exercise), post-acquisition, making it possible to selectively examine memory storage and consolidation. Accordingly we evaluated the effects of post-trial exercise (10 min on a treadmill) on memory consolidation in aged canines both right after, an hour after, and 24 h after acute exercise training in concurrent discrimination, object location memory (OLM), and novel object recognition tasks. Our study shows that post-trial exercise facilitates memory function by improving memory consolidation in aged animals in a time-dependent manner. The improvements were significant at 24 h post-exercise and not right after or 1 h after exercise. Aged animals were also tested following chronic exercise (10 min/day for 14 consecutive days) on OLM or till criterion were reached (for reversal learning task). We found improvements from a chronic exercise design in both the object location and reversal learning tasks. Our studies suggest that mechanisms to improve overall consolidation and cognitive function remain accessible even with progressing age and can be re-engaged by both acute and chronic exercise.

  1. Consolidation and reconsolidation: two lives of memories?

    Science.gov (United States)

    McKenzie, Sam; Eichenbaum, Howard

    2011-07-28

    Most studies on memory consolidation consider the new information as if it were imposed on a tabula rasa, but considerable evidence indicates that new memories must be interleaved within a large network of relevant pre-existing knowledge. Early studies on reconsolidation highlighted that a newly consolidated memory could be erased after reactivation, but new evidence has shown that an effective reactivation experience must also involve memory reorganization to incorporate new learning. The combination of these observations on consolidation and reconsolidation highlights the fundamental similarities of both phenomena as the integration of new information and old, and it suggests reconsolidation = consolidation as a neverending process of schema modification. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. A unified theory for systems and cellular memory consolidation.

    Science.gov (United States)

    Dash, Pramod K; Hebert, April E; Runyan, Jason D

    2004-04-01

    The time-limited role of the hippocampus for explicit memory storage has been referred to as systems consolidation where learning-related changes occur first in the hippocampus followed by the gradual development of a more distributed memory trace in the neocortex. Recent experiments are beginning to show that learning induces plasticity-related molecular changes in the neocortex as well as in the hippocampus and with a similar time course. Present memory consolidation theories do not account for these findings. In this report, we present a theory (the C theory) that incorporates these new findings, provides an explanation for the length of time for hippocampal dependency, and that can account for the apparent longer consolidation periods in species with larger brains. This theory proposes that a process of cellular consolidation occurs in the hippocampus and in areas of the neocortex during and shortly after learning resulting in long-term memory storage in both areas. For a limited time, the hippocampus is necessary for memory retrieval, a process involving the coordinated reactivation of these areas. This reactivation is later mediated by longer extrahippocampal connectivity between areas. The delay in hippocampal-independent memory retrieval is the time it takes for gene products in these longer extrahippocampal projections to be transported from the soma to tagged synapses by slow axonal transport. This cellular transport event defines the period of hippocampal dependency and, thus, the duration of memory consolidation. The theoretical description for memory consolidation presented in this review provides alternative explanations for several experimental observations and presents a unification of the concepts of systems and cellular memory consolidation.

  3. Consolidation of object recognition memory requires HRI kinase-dependent phosphorylation of eIF2α in the hippocampus.

    Science.gov (United States)

    ILL-Raga, Gerard; Köhler, Cristiano; Radiske, Andressa; Lima, Ramón H; Rosen, Mark D; Muñoz, Francisco J; Cammarota, Martín

    2013-06-01

    Local control of protein synthesis at synapses is crucial for synaptic plasticity and memory formation. However, little is known about the signals coupling neurotransmitter release with the translational machinery during these processes. Here, we studied the involvement of heme-regulated inhibitor (HRI) kinase, a kinase activated by nitric oxide that phosphorylates eukaryotic initiation factor 2α (eIF2α), in object recognition (OR) memory consolidation. Phosphorylated eIF2α mediates two opposing effects upon translation: translational arrest of most mRNAs and translational activation of selected mRNAs bearing specific features in their 5'untranslated regions (5'UTRs). We found that HRI kinase activation in the CA1 region of the dorsal hippocampus is necessary for retention of OR memory in rats. Accordingly, learning induced a transient increase in the phosphorylation state of eIF2α in dorsal CA1 which was abolished by the HRI kinase inhibitor N-(2,6-dimethylbenzyl)-6,7-dimethoxy-2H-[1]benzofuro[3,2-c]pyrazol-3-amine hydrochloride (AMI). The increase in p-eIF2α was associated with increased expression of BACE1 and activating transcription factor 4, two proteins containing eIF2α-responsive 5'UTRs in their mRNAs that play a key role in synaptic plasticity. Our data suggests that learning promotes the transient phosphorylation of eIF2α to allow for translation of specific 5'UTR-mRNAs through a process requiring HRI kinase activation. Copyright © 2013 Wiley Periodicals, Inc.

  4. Hippocampal-neocortical interactions in memory formation, consolidation, and reconsolidation.

    Science.gov (United States)

    Wang, Szu-Han; Morris, Richard G M

    2010-01-01

    This review, focusing on work using animals, updates a theoretical approach whose aim is to translate neuropsychological ideas about the psychological and anatomical organization of memory into the neurobiological domain. It is suggested that episodic-like memory consists of both automatic and controlled components, with the medial temporal mediation of memory encoding including neurobiological mechanisms that are primarily automatic or incidental. These ideas, in the cognitive and behavioral domain, are linked to neurophysiological ideas about cellular consolidation concerning synaptic potentiation, particularly the relationship between protein synthesis-dependent long-term changes and shorter-lasting post-translational mechanisms. Ideas from psychology about mental schemas are considered in relation to the phenomenon of systems consolidation and, specifically, about how prior knowledge can alter the rate at which consolidation occurs. Finally, the hippocampal-neocortical interactions theory is updated in relation to reconsolidation, a process that enables updating of stored memory traces in response to novelty.

  5. Acute exercise and motor memory consolidation

    DEFF Research Database (Denmark)

    Thomas, Richard; Beck, Mikkel Malling; Lind, Rune Rasmussen

    2016-01-01

    of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs), healthy male subjects randomly...... greater for EX90 than CON (p improvements in procedural memory......High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity...

  6. Memory Consolidation and Neural Substrate of Reward

    Directory of Open Access Journals (Sweden)

    Redolar-Ripoll, Diego

    2012-08-01

    Full Text Available The aim of this report is to analyze the relationships between reward and learning and memory processes. Different studies have described how information about rewards influences behavior and how the brain uses this reward information to control learning and memory processes. Reward nature seems to be processed in different ways by neurons in different brain structures, ranging from the detection and perception of rewards to the use of information about predicted rewards for the control of goal-directed behavior. The neural substrate underling this processing of reward information is a reliable way of improving learning and memory processes. Evidence from several studies indicates that this neural system can facilitate memory consolidation in a wide variety of learning tasks. From a molecular perspective, certain cardinal features of reward have been described as forms of memory. Studies of human addicts and studies in animal models of addiction show that chronic drug exposure produces stable changes in the brain at the cellular and molecular levels that underlie the long-lasting behavioral plasticity associated with addiction. These molecular and cellular adaptations involved in addiction are also implicated in learning and memory processes. Dopamine seems to be a critical common signal to activate different genetic mechanisms that ultimately remodel synapses and circuits. Despite memory is an active and complex process mediated by different brain areas, the neural substrate of reward is able to improve memory consolidation in a several paradigms. We believe that there are many equivalent traits between reward and learning and memory processes.

  7. Orexin receptor-1 in the locus coeruleus plays an important role in cue-dependent fear memory consolidation.

    Science.gov (United States)

    Soya, Shingo; Shoji, Hirotaka; Hasegawa, Emi; Hondo, Mari; Miyakawa, Tsuyoshi; Yanagisawa, Masashi; Mieda, Michihiro; Sakurai, Takeshi

    2013-09-01

    The noradrenergic (NA) projections arising from the locus ceruleus (LC) to the amygdala and bed nucleus of the stria terminalis have been implicated in the formation of emotional memory. Since NA neurons in the LC (LC-NA neurons) abundantly express orexin receptor-1 (OX1R) and receive prominent innervation by orexin-producing neurons, we hypothesized that an OX1R-mediated pathway is involved in the physiological fear learning process via regulation of LC-NA neurons. To evaluate this hypothesis, we examined the phenotype of Ox1r(-/-) mice in the classic cued and contextual fear-conditioning test. We found that Ox1r(-/-) mice showed impaired freezing responses in both cued and contextual fear-conditioning paradigms. In contrast, Ox2r(-/-) mice showed normal freezing behavior in the cued fear-conditioning test, while they exhibited shorter freezing time in the contextual fear-conditioning test. Double immunolabeling of Fos and tyrosine hydroxylase showed that double-positive LC-NA neurons after test sessions of both cued and contextual stimuli were significantly fewer in Ox1r(-/-) mice. AAV-mediated expression of OX1R in LC-NA neurons in Ox1r(-/-) mice restored the freezing behavior to the auditory cue to a comparable level to that in wild-type mice in the test session. Decreased freezing time during the contextual fear test was not affected by restoring OX1R expression in LC-NA neurons. These observations support the hypothesis that the orexin system modulates the formation and expression of fear memory via OX1R in multiple pathways. Especially, OX1R in LC-NA neurons plays an important role in cue-dependent fear memory formation and/or retrieval.

  8. Autobiographical thinking interferes with episodic memory consolidation.

    Directory of Open Access Journals (Sweden)

    Michael Craig

    Full Text Available New episodic memories are retained better if learning is followed by a few minutes of wakeful rest than by the encoding of novel external information. Novel encoding is said to interfere with the consolidation of recently acquired episodic memories. Here we report four experiments in which we examined whether autobiographical thinking, i.e. an 'internal' memory activity, also interferes with episodic memory consolidation. Participants were presented with three wordlists consisting of common nouns; one list was followed by wakeful rest, one by novel picture encoding and one by autobiographical retrieval/future imagination, cued by concrete sounds. Both novel encoding and autobiographical retrieval/future imagination lowered wordlist retention significantly. Follow-up experiments demonstrated that the interference by our cued autobiographical retrieval/future imagination delay condition could not be accounted for by the sound cues alone or by executive retrieval processes. Moreover, our results demonstrated evidence of a temporal gradient of interference across experiments. Thus, we propose that rich autobiographical retrieval/future imagination hampers the consolidation of recently acquired episodic memories and that such interference is particularly likely in the presence of external concrete cues.

  9. [Sleep-wake cycle and memory consolidation].

    Science.gov (United States)

    Baratti, Carlos M; Boccia, Mariano M; Blake, Mariano G; Acosta, Gabriela B

    2007-01-01

    Although several hypothesis and theories have been advanced as explanations for the functions of sleep, a unified theory of sleep function remains elusive. Sleep has been implicated in the plastic cerebral changes that underlie learning and memory, in particular those related to memory consolidation of recently acquired new information. Despite steady accumulations of positive findings over the last ten years, the precise role of sleep in memory and brain plasticity is unproven at all. This situation might be solved by more integrated approaches that combine behavioral and neurophysiological measurements in well described in vivo models of neuronal activity and brain plasticity.

  10. Spatial Memory Consolidation is Associated with Induction of Several Lysine-Acetyltransferase (Histone Acetyltransferase) Expression Levels and H2B/H4 Acetylation-Dependent Transcriptional Events in the Rat Hippocampus

    Science.gov (United States)

    Bousiges, Olivier; Vasconcelos, Anne Pereira de; Neidl, Romain; Cosquer, Brigitte; Herbeaux, Karine; Panteleeva, Irina; Loeffler, Jean-Philippe; Cassel, Jean-Christophe; Boutillier, Anne-Laurence

    2010-01-01

    Numerous genetic studies have shown that the CREB-binding protein (CBP) is an essential component of long-term memory formation, through its histone acetyltransferase (HAT) function. E1A-binding protein p300 and p300/CBP-associated factor (PCAF) have also recently been involved in memory formation. By contrast, only a few studies have reported on acetylation modifications during memory formation, and it remains unclear as to how the system is regulated during this dynamic phase. We investigated acetylation-dependent events and the expression profiles of these HATs during a hippocampus-dependent task taxing spatial reference memory in the Morris water maze. We found a specific increase in H2B and H4 acetylation in the rat dorsal hippocampus, while spatial memory was being consolidated. This increase correlated with the degree of specific acetylated histones enrichment on some memory/plasticity-related gene promoters. Overall, a global increase in HAT activity was measured during this memory consolidation phase, together with a global increase of CBP, p300, and PCAF expression. Interestingly, these regulations were altered in a model of hippocampal denervation disrupting spatial memory consolidation, making it impossible for the hippocampus to recruit the CBP pathway (CBP regulation and acetylated-H2B-dependent transcription). CBP has long been thought to be present in limited concentrations in the cells. These results show, for the first time, that CBP, p300, and PCAF are dynamically modulated during the establishment of a spatial memory and are likely to contribute to the induction of a specific epigenetic tagging of the genome for hippocampus-dependent (spatial) memory consolidation. These findings suggest the use of HAT-activating molecules in new therapeutic strategies of pathological aging, Alzheimer's disease, and other neurodegenerative disorders. PMID:20811339

  11. Consolidation and reconsolidation of object recognition memory.

    Science.gov (United States)

    Balderas, Israela; Rodriguez-Ortiz, Carlos J; Bermudez-Rattoni, Federico

    2015-05-15

    In the first part of this review, we will present evidence showing a functional double dissociation between different structures of the medial temporal lobe in the consolidation of object and object-in-context recognition memory. In addition, we will provide evidence to support this differential participation through protein synthesis inhibitors and neurotransmitters antagonists and agonists. This evidence points out that the perirhinal, prefrontal and insular cortices consolidate the information of individual stimuli, i.e., objects, while the hippocampus consolidates the contextual information where the objects were experimented. In the second part of this review, we will present evidence that shows that the perirhinal cortex is also necessary for reconsolidation of ORM; the destabilization/re-stabilization memory process upon its activation. In the final part of this review, we will present evidence that shows that ORM reconsolidation is an independent process from its retrieval in the perirhinal cortex. Altogether, this review depicts part of the mechanisms by which the medial temporal lobe processes the functional components of recognition memory, in both consolidation and reconsolidation.

  12. Object recognition memory: neurobiological mechanisms of encoding, consolidation and retrieval.

    Science.gov (United States)

    Winters, Boyer D; Saksida, Lisa M; Bussey, Timothy J

    2008-07-01

    Tests of object recognition memory, or the judgment of the prior occurrence of an object, have made substantial contributions to our understanding of the nature and neurobiological underpinnings of mammalian memory. Only in recent years, however, have researchers begun to elucidate the specific brain areas and neural processes involved in object recognition memory. The present review considers some of this recent research, with an emphasis on studies addressing the neural bases of perirhinal cortex-dependent object recognition memory processes. We first briefly discuss operational definitions of object recognition and the common behavioural tests used to measure it in non-human primates and rodents. We then consider research from the non-human primate and rat literature examining the anatomical basis of object recognition memory in the delayed nonmatching-to-sample (DNMS) and spontaneous object recognition (SOR) tasks, respectively. The results of these studies overwhelmingly favor the view that perirhinal cortex (PRh) is a critical region for object recognition memory. We then discuss the involvement of PRh in the different stages--encoding, consolidation, and retrieval--of object recognition memory. Specifically, recent work in rats has indicated that neural activity in PRh contributes to object memory encoding, consolidation, and retrieval processes. Finally, we consider the pharmacological, cellular, and molecular factors that might play a part in PRh-mediated object recognition memory. Recent studies in rodents have begun to indicate the remarkable complexity of the neural substrates underlying this seemingly simple aspect of declarative memory.

  13. Money enhances memory consolidation--but only for boring material.

    Science.gov (United States)

    Murayama, Kou; Kuhbandner, Christof

    2011-04-01

    Money's ability to enhance memory has received increased attention in recent research. However, previous studies have not directly addressed the time-dependent nature of monetary effects on memory, which are suggested to exist by research in cognitive neuroscience, and the possible detrimental effects of monetary rewards on learning interesting material, as indicated by studies in motivational psychology. By utilizing a trivia question paradigm, the current study incorporated these perspectives and examined the effect of monetary rewards on immediate and delayed memory performance for answers to uninteresting and interesting questions. Results showed that monetary rewards promote memory performance only after a delay. In addition, the memory enhancement effect of monetary rewards was only observed for uninteresting questions. These results are consistent with both the hippocampus-dependent memory consolidation model of reward learning and previous findings documenting the ineffectiveness of monetary rewards on tasks that have intrinsic value.

  14. Consolidation of statistical information of multiple objects in working memory.

    Science.gov (United States)

    Baijal, Shruti; Srinivasan, Narayanan

    2011-08-01

    The present study investigated working memory consolidation in focused and distributed attention tasks by examining the time course of the consolidation process (Experiment 1) and its dependence on capacity-limited central resources (Experiment 2) in both tasks. In a match-to-sample design using masks at various intervals to vary consolidation rates, the participants performed either an identification task (focused attention) or a mean estimation task (distributed attention) with (Experiment 1) or without (Experiment 2) prior knowledge of what task they were to perform. We found that consolidation in the distributed attention task was more efficient and was about twice as fast as in the focused attention task. In addition, both tasks suffered interference when they had to be performed together, indicating that both types of attention rely on a common set of control processes. These findings can be attributed to differences in the resolution of object representations and in the scope of attention associated with focused and distributed attention.

  15. Acute exercise and motor memory consolidation

    DEFF Research Database (Denmark)

    Thomas, Richard; Johnsen, Line Korsgaard; Geertsen, Svend Sparre;

    2016-01-01

    an important role in modulating the effects that a single bout of cardiovascular exercise has on the consolidation phase following motor skill learning. There appears to be a dose-response relationship in favour of higher intensity exercise in order to augment off-line effects and strengthen procedural memory.......A single bout of high intensity aerobic exercise (~90% VO2peak) was previously demonstrated to amplify off-line gains in skill level during the consolidation phase of procedural memory. High intensity exercise is not always a viable option for many patient groups or in a rehabilitation setting...... where low to moderate intensities may be more suitable. The aim of this study was to investigate the role of intensity in mediating the effects of acute cardiovascular exercise on motor skill learning. We investigated the effects of different exercise intensities on the retention (performance score...

  16. Memory enhancement after drinking ethanol: consolidation, interference, or response bias?

    Science.gov (United States)

    Tyson, P D; Schirmuly, M

    1994-11-01

    One explanation for memory facilitation is that alcohol has a short-term neurochemical stimulating effect on consolidating neural networks when material is learned before drinking. Contrary to the consolidation hypothesis, when the consolidation interval was manipulated the results showed that the effects of alcohol were not time dependent. Compared to placebo subjects, alcohol significantly facilitated the recall of 25 words whether administered immediately or 40 min after learning. In addition, alcohol significantly increased the memory of words associated with pictures when incidentally learned before drinking and significantly decreased incidental learning after drinking. Another explanation for memory facilitation is that alcohol's depressive physiological effect impairs the acquisition of new information, like sleeping after learning, and enhances memory by reducing subsequent interference. Consistent with the retroactive interference hypothesis, the effects of alcohol reduced interpolated interference, were greater on recall than recognition, and were immune to time delays. Contemporary theories view memory enhancement attributed to alcohol as indirectly influencing response biases and contextual cues associated with retrieval from episodic memory.

  17. Post-learning molecular reactivation underlies taste memory consolidation

    Directory of Open Access Journals (Sweden)

    Kioko eGuzman-Ramos

    2011-09-01

    Full Text Available It is considered that memory consolidation is a progressive process that requires post-trial stabilization of the information. In this regard, it has been speculated that waves of receptors activation, expression of immediate early genes and replenishment of receptor subunit pools occur to induce functional or morphological changes to maintain the information for longer periods. In this paper, we will review data related to neuronal changes in the post-acquisition stage of taste aversion learning that could be involved in further stabilization of the memory trace. In order to achieve such stabilization, evidence suggests that the functional integrity of the insular cortex (IC and the amygdala (AMY is required. Particularly the increase of extracellular levels of glutamate and activation of N-methyl-D-aspartate (NMDA receptors within the IC shows a main role in the consolidation process. Additionally the modulatory actions of the dopaminergic system in the IC appear to be involved in the mechanisms that lead to taste aversion memory consolidation through the activation of pathways related to enhancement of protein synthesis such as the Protein Kinase A pathway. In summary, we suggest that post-acquisition molecular and neuronal changes underlying memory consolidation are dependent on the interactions between the AMY and the IC.

  18. Involvement of Spindles in Memory Consolidation Is Slow Wave Sleep-Specific

    Science.gov (United States)

    Cox, Roy; Hofman, Winni F.; Talamini, Lucia M.

    2012-01-01

    Both sleep spindles and slow oscillations have been implicated in sleep-dependent memory consolidation. Whereas spindles occur during both light and deep sleep, slow oscillations are restricted to deep sleep, raising the possibility of greater consolidation-related spindle involvement during deep sleep. We assessed declarative memory retention…

  19. Corticosterone infused into the dorsal striatum selectively enhances memory consolidation of cued water-maze training

    NARCIS (Netherlands)

    Quirarte, Gina L.; Sofia Ledesma de la Teja, I.; Casillas, Miriam; Serafin, Norma; Prado-Alcala, Roberto A.; Roozendaal, Benno

    2009-01-01

    Glucocorticoid hormones enhance memory consolidation of hippocampus-dependent spatial/contextual learning, but little is known about their possible influence on the consolidation of procedural/implicit memory. Therefore, in this study we examined the effect of corticosterone (2, 5, or 10 ng) infused

  20. Corticosterone infused into the dorsal striatum selectively enhances memory consolidation of cued water-maze training

    NARCIS (Netherlands)

    Quirarte, Gina L.; Sofia Ledesma de la Teja, I.; Casillas, Miriam; Serafin, Norma; Prado-Alcala, Roberto A.; Roozendaal, Benno

    2009-01-01

    Glucocorticoid hormones enhance memory consolidation of hippocampus-dependent spatial/contextual learning, but little is known about their possible influence on the consolidation of procedural/implicit memory. Therefore, in this study we examined the effect of corticosterone (2, 5, or 10 ng) infused

  1. Emotional memory consolidation under lower versus higher stress conditions

    Directory of Open Access Journals (Sweden)

    Inna eKogan

    2010-12-01

    Full Text Available 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 high versus low emotionality conditions. When spatial learning was followed by reversal training interference, impaired retention was detected only under high emotionality conditions. Here we further evaluate the potential implications of the difference in the level of amygdala activation on the quality of the memory formed under these stress conditions. We attempted to affect spatial memory consolidation under low or high stress conditions by either introducing a foot shock interference following massed training in the water maze; by manipulating the threshold for acquisition employing either brief (3 trials or full (12 trials training sessions; or by employing a spaced training (over three days rather than massed training protocol. The current findings reveal that under heightened emotionality, the process of consolidation seems to become less effective and more vulnerable to interference; however, when memory consolidation is not interrupted, retention is improved. These differential effects might underlie the complex interactions of stress, and, particularly, of traumatic stress with memory formation processes.

  2. Acute Exercise Enhances the Consolidation of Fear Extinction Memory and Reduces Conditioned Fear Relapse in a Sex-Dependent Manner

    Science.gov (United States)

    Bouchet, Courtney A.; Lloyd, Brian A.; Loetz, Esteban C.; Farmer, Caroline E.; Ostrovskyy, Mykola; Haddad, Natalie; Foright, Rebecca M.; Greenwood, Benjamin N.

    2017-01-01

    Fear extinction-based exposure therapy is the most common behavioral therapy for anxiety and trauma-related disorders, but fear extinction memories are labile and fear tends to return even after successful extinction. The relapse of fear contributes to the poor long-term efficacy of exposure therapy. A single session of voluntary exercise can…

  3. The regulation of transcription in memory consolidation.

    Science.gov (United States)

    Alberini, Cristina M; Kandel, Eric R

    2014-12-04

    De novo transcription of DNA is a fundamental requirement for the formation of long-term memory. It is required during both consolidation and reconsolidation, the posttraining and postreactivation phases that change the state of the memory from a fragile into a stable and long-lasting form. Transcription generates both mRNAs that are translated into proteins, which are necessary for the growth of new synaptic connections, as well as noncoding RNA transcripts that have regulatory or effector roles in gene expression. The result is a cascade of events that ultimately leads to structural changes in the neurons that mediate long-term memory storage. The de novo transcription, critical for synaptic plasticity and memory formation, is orchestrated by chromatin and epigenetic modifications. The complexity of transcription regulation, its temporal progression, and the effectors produced all contribute to the flexibility and persistence of long-term memory formation. In this article, we provide an overview of the mechanisms contributing to this transcriptional regulation underlying long-term memory formation.

  4. Canonical Wnt signaling is necessary for object recognition memory consolidation.

    Science.gov (United States)

    Fortress, Ashley M; Schram, Sarah L; Tuscher, Jennifer J; Frick, Karyn M

    2013-07-31

    Wnt signaling has emerged as a potent regulator of hippocampal synaptic function, although no evidence yet supports a critical role for Wnt signaling in hippocampal memory. Here, we sought to determine whether canonical β-catenin-dependent Wnt signaling is necessary for hippocampal memory consolidation. Immediately after training in a hippocampal-dependent object recognition task, mice received a dorsal hippocampal (DH) infusion of vehicle or the canonical Wnt antagonist Dickkopf-1 (Dkk-1; 50, 100, or 200 ng/hemisphere). Twenty-four hours later, mice receiving vehicle remembered the familiar object explored during training. However, mice receiving Dkk-1 exhibited no memory for the training object, indicating that object recognition memory consolidation is dependent on canonical Wnt signaling. To determine how Dkk-1 affects canonical Wnt signaling, mice were infused with vehicle or 50 ng/hemisphere Dkk-1 and protein levels of Wnt-related proteins (Dkk-1, GSK3β, β-catenin, TCF1, LEF1, Cyclin D1, c-myc, Wnt7a, Wnt1, and PSD95) were measured in the dorsal hippocampus 5 min or 4 h later. Dkk-1 produced a rapid increase in Dkk-1 protein levels and a decrease in phosphorylated GSK3β levels, followed by a decrease in β-catenin, TCF1, LEF1, Cyclin D1, c-myc, Wnt7a, and PSD95 protein levels 4 h later. These data suggest that alterations in Wnt/GSK3β/β-catenin signaling may underlie the memory impairments induced by Dkk-1. In a subsequent experiment, object training alone rapidly increased DH GSK3β phosphorylation and levels of β-catenin and Cyclin D1. These data suggest that canonical Wnt signaling is regulated by object learning and is necessary for hippocampal memory consolidation.

  5. Sleep-Dependent Consolidation of Procedural Motor Memories in Children and Adults: The Pre-Sleep Level of Performance Matters

    Science.gov (United States)

    Wilhelm, Ines; Metzkow-Meszaros, Maila; Knapp, Susanne; Born, Jan

    2012-01-01

    In striking contrast to adults, in children sleep following training a motor task did not induce the expected (offline) gain in motor skill performance in previous studies. Children normally perform at distinctly lower levels than adults. Moreover, evidence in adults suggests that sleep dependent offline gains in skill essentially depend on the…

  6. Sleep-Dependent Consolidation of Procedural Motor Memories in Children and Adults: The Pre-Sleep Level of Performance Matters

    Science.gov (United States)

    Wilhelm, Ines; Metzkow-Meszaros, Maila; Knapp, Susanne; Born, Jan

    2012-01-01

    In striking contrast to adults, in children sleep following training a motor task did not induce the expected (offline) gain in motor skill performance in previous studies. Children normally perform at distinctly lower levels than adults. Moreover, evidence in adults suggests that sleep dependent offline gains in skill essentially depend on the…

  7. Engagement of the PFC in Consolidation and Recall of Recent Spatial Memory

    Science.gov (United States)

    Leon, Wanda C.; Bruno, Martin A.; Allard, Simon; Nader, Karim; Cuello, A. Claudio

    2010-01-01

    The standard model of system consolidation proposes that memories are initially hippocampus dependent and become hippocampus independent over time. Previous studies have demonstrated the involvement of the medial prefrontal cortex (mPFC) in the retrieval of remote memories. The transformations required to make a memory undergo system's…

  8. Test Expectation Enhances Memory Consolidation across Both Sleep and Wake.

    Science.gov (United States)

    Wamsley, Erin J; Hamilton, Kelly; Graveline, Yvette; Manceor, Stephanie; Parr, Elaine

    2016-01-01

    Memory consolidation benefits from post-training sleep. However, recent studies suggest that sleep does not uniformly benefit all memory, but instead prioritizes information that is important to the individual. Here, we examined the effect of test expectation on memory consolidation across sleep and wakefulness. Following reports that information with strong "future relevance" is preferentially consolidated during sleep, we hypothesized that test expectation would enhance memory consolidation across a period of sleep, but not across wakefulness. To the contrary, we found that expectation of a future test enhanced memory for both spatial and motor learning, but that this effect was equivalent across both wake and sleep retention intervals. These observations differ from those of least two prior studies, and fail to support the hypothesis that the "future relevance" of learned material moderates its consolidation selectively during sleep.

  9. Sleep-related memory consolidation in primary insomnia.

    Science.gov (United States)

    Nissen, Christoph; Kloepfer, Corinna; Feige, Bernd; Piosczyk, Hannah; Spiegelhalder, Kai; Voderholzer, Ulrich; Riemann, Dieter

    2011-03-01

    It has been suggested that healthy sleep facilitates the consolidation of newly acquired memories and underlying brain plasticity. The authors tested the hypothesis that patients with primary insomnia (PI) would show deficits in sleep-related memory consolidation compared to good sleeper controls (GSC). The study used a four-group parallel design (n=86) to investigate the effects of 12 h of night-time, including polysomnographically monitored sleep ('sleep condition' in PI and GSC), versus 12 h of daytime wakefulness ('wake condition' in PI and GSC) on procedural (mirror tracing task) and declarative memory consolidation (visual and verbal learning task). Demographic characteristics and memory encoding did not differ between the groups at baseline. Polysomnography revealed a significantly disturbed sleep profile in PI compared to GSC in the sleep condition. Night-time periods including sleep in GSC were associated with (i) a significantly enhanced procedural and declarative verbal memory consolidation compared to equal periods of daytime wakefulness in GSC and (ii) a significantly enhanced procedural memory consolidation compared to equal periods of daytime wakefulness and night-time sleep in PI. Across retention intervals of daytime wakefulness, no differences between the experimental groups were observed. This pattern of results suggests that healthy sleep fosters the consolidation of new memories, and that this process is impaired for procedural memories in patients with PI. Future work is needed to investigate the impact of treatment on improving sleep and memory.

  10. Memory consolidation during sleep: interactive effects of sleep stages and HPA regulation.

    Science.gov (United States)

    Wagner, Ullrich; Born, Jan

    2008-01-01

    Sleep is critically involved in the consolidation of previously acquired memory traces. However, nocturnal sleep is not uniform but is subject to distinct changes in electrophysiological and neuroendocrine activity. Specifically, the first half of the night is dominated by slow wave sleep (SWS), whereas rapid eye movement (REM) sleep prevails in the second half. Concomitantly, hypothalamo-pituitary-adrenal (HPA) activity as indicated by cortisol release is suppressed to a minimum during early sleep, while drastically increasing during late sleep. We have shown that the different sleep stages and the concomitant glucocorticoid release are interactively involved in the consolidation of different types of memories. SWS-rich early sleep has been demonstrated to benefit mainly the consolidation of hippocampus-dependent declarative memories (i.e. facts and episodes). In contrast, REM sleep-rich late sleep was shown to improve in particular emotional memories involving amygdalar function, as well as procedural memories (for skills) not depending on hippocampal or amygdalar function. Enhancing plasma glucocorticoid concentrations during SWS-rich early sleep counteracted hippocampus-dependent declarative memory consolidation, but did not affect hippocampus-independent procedural memory. Preventing the increase in cortisol during late REM sleep-rich sleep by administration of metyrapone impaired hippocampus-dependent declarative memory but enhanced amygdala-dependent emotional aspects of memory. The data underscore the importance of pituitary-adrenal inhibition during early SWS-rich sleep for efficient consolidation of declarative memory. The increase in cortisol release during late REM sleep-rich sleep may counteract an overshooting consolidation of emotional memories.

  11. Simultaneous EEG-fMRI studies of sleep-dependent memory consolidation%睡眠影响记忆巩固的同步 EEG-fMRI 研究

    Institute of Scientific and Technical Information of China (English)

    雷旭; 赵文瑞

    2016-01-01

    默认网络是静息状态活动较强的大脑结构,它包含的海马和内侧前额叶两个脑区是记忆巩固的关键部位,同时静息态也被证明伴随有记忆巩固现象,我们推测默认网络是睡眠依赖记忆巩固的核心结构。本研究拟借助同步 EEG-fMRI 在时空分辨率上的优势,研究默认网络参与睡眠依赖记忆巩固的神经机制。包括:1)发掘默认网络活动的电生理指标,应用 EEG 源定位和跨频段耦合分析,揭示记忆巩固的动态过程;2)应用滑动时间窗和模块分析,研究默认网络参与静息态和睡眠过程记忆巩固的异同,揭示记忆在昼夜更迭中得以强化的神经机制;3)通过多模态信息融合,揭示记忆类型和睡眠阶段等因素对睡眠依赖记忆巩固的影响。本研究的开展对阐明睡眠依赖记忆巩固的神经机制具有深刻的理论意义,并最终可能为治疗学习记忆相关障碍提供全新的思路。%The default mode network (DMN) is a brain structure persisting activity during the resting state. As resting state has been demonstrated with function of memory consolidation and sub-regions of DMN, the hippocampus and medial prefrontal cortex, are the key regions of memory consolidation, we hypothesize that the DMN is the core structure of sleep-dependent memory consolidation. With the high resolution in temporal and spatial domain of simultaneous EEG-fMRI, we will study the neural mechanisms of the DMN-involved memory consolidation, which includes: 1) describing the dynamic process of memory consolidation based on the EEG source localization and cross-frequency coupling analysis; 2) distinguishing the functional connectivity of DMN during resting and sleep states based on the sliding time-window and module analysis to reveal the basic principles of memory enhancement within the iteration of day and night;3) revealing the influences of types of memory and sleep stages in memory consolidation

  12. Memory processes during sleep: beyond the standard consolidation theory.

    Science.gov (United States)

    Axmacher, Nikolai; Draguhn, Andreas; Elger, Christian E; Fell, Juergen

    2009-07-01

    Two-step theories of memory formation suggest that an initial encoding stage, during which transient neural assemblies are formed in the hippocampus, is followed by a second step called consolidation, which involves re-processing of activity patterns and is associated with an increasing involvement of the neocortex. Several studies in human subjects as well as in animals suggest that memory consolidation occurs predominantly during sleep (standard consolidation model). Alternatively, it has been suggested that consolidation may occur during waking state as well and that the role of sleep is rather to restore encoding capabilities of synaptic connections (synaptic downscaling theory). Here, we review the experimental evidence favoring and challenging these two views and suggest an integrative model of memory consolidation.

  13. Autobiographical memory and hyperassociativity in the dreaming brain: Implications for memory consolidation in sleep

    Directory of Open Access Journals (Sweden)

    Caroline L Horton

    2015-07-01

    Full Text Available In this paper we argue that autobiographical memory activity across sleep and wake can provide insight into the nature of dreaming, and vice versa. Activated memories within the sleeping brain reflect one’s personal life history (autobiography. They can appear in largely fragmentary forms and differ from conventional manifestations of episodic memory. Autobiographical memories in dreams can be sampled from non-REM as well as REM periods, which contain fewer episodic references and become more bizarre across the night. Salient fragmented memory features are activated in sleep and re-bound with fragments not necessarily emerging from the same memory, thus de-contextualising those memories and manifesting as experiences that differ from waking conceptions. The constructive nature of autobiographical recall further encourages synthesis of these hyper-associated images into an episode via recalling and reporting dreams. We use a model of autobiographical memory to account for the activation of memories in dreams as a reflection of sleep-dependent memory consolidation processes. We focus in particular on the hyperassociative nature of autobiographical memory during sleep.

  14. On the Role of Hippocampal Protein Synthesis in the Consolidation and Reconsolidation of Object Recognition Memory

    Science.gov (United States)

    Rossato, Janine I.; Bevilaqua, Lia R. M.; Myskiw, Jociane C.; Medina, Jorge H.; Izquierdo, Ivan; Cammarota, Martin

    2007-01-01

    Upon retrieval, consolidated memories are again rendered vulnerable to the action of metabolic blockers, notably protein synthesis inhibitors. This has led to the hypothesis that memories are reconsolidated at the time of retrieval, and that this depends on protein synthesis. Ample evidence indicates that the hippocampus plays a key role both in…

  15. Exercise enhances memory consolidation in the aging brain

    OpenAIRE

    Shikha eSnigdha; Christina ede Rivera; Milgram, Norton W.; Carl eCotman

    2014-01-01

    Exercise has been shown to reduce age-related losses in cognitive function including learning and memory, but the mechanisms underlying this effect remain poorly understood. Memory formation occurs in stages that include an initial acquisition phase, an intermediate labile phase, and then a process of consolidation which leads to long term memory formation. An effective way to examine the mechanism by which exercise improves memory is to introduce the intervention (exercise), post-acquisition...

  16. Low acetylcholine during slow-wave sleep is critical for declarative memory consolidation.

    Science.gov (United States)

    Gais, Steffen; Born, Jan

    2004-02-17

    The neurotransmitter acetylcholine is considered essential for proper functioning of the hippocampus-dependent declarative memory system, and it represents a major neuropharmacological target for the treatment of memory deficits, such as those in Alzheimer's disease. During slow-wave sleep (SWS), however, declarative memory consolidation is particularly strong, while acetylcholine levels in the hippocampus drop to a minimum. Observations in rats led to the hypothesis that the low cholinergic tone during SWS is necessary for the replay of new memories in the hippocampus and their long-term storage in neocortical networks. However, this low tone should not affect nondeclarative memory systems. In this study, increasing central nervous cholinergic activation during SWS-rich sleep by posttrial infusion of 0.75 mg of the cholinesterase inhibitor physostigmine completely blocked SWS-related consolidation of declarative memories for word pairs in human subjects. The treatment did not interfere with consolidation of a nondeclarative mirror tracing task. Also, physostigmine did not alter memory consolidation during waking, when the endogenous central nervous cholinergic tone is maximal. These findings are in line with predictions that a low cholinergic tone during SWS is essential for declarative memory consolidation.

  17. New insights in human memory interference and consolidation.

    Science.gov (United States)

    Robertson, Edwin M

    2012-01-24

    Learning new facts and skills in succession can be frustrating because no sooner has new knowledge been acquired than its retention is being jeopardized by learning another set of skills or facts. Interference between memories has recently provided important new insights into the neural and psychological systems responsible for memory processing. For example, interference not only occurs between the same types of memories, but can also occur between different types of memories, which has important implications for our understanding of memory organization. Converging evidence has begun to reveal that the brain produces interference independently from other aspects of memory processing, which suggests that interference may have an important but previously overlooked function. A memory's initial susceptibility to interference and subsequent resistance to interference after its acquisition has revealed that memories continue to be processed 'off-line' during consolidation. Recent work has demonstrated that off-line processing is not limited to just the stabilization of a memory, which was once the defining characteristic of consolidation; instead, off-line processing can have a rich diversity of effects, from enhancing performance to making hidden rules explicit. Off-line processing also occurs after memory retrieval when memories are destabilized and then subsequently restabalized during reconsolidation. Studies are beginning to reveal the function of reconsolidation, its mechanistic relationship to consolidation and its potential as a therapeutic target for the modification of memories. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Peripheral and central CB1 cannabinoid receptors control stress-induced impairment of memory consolidation

    Science.gov (United States)

    Busquets-Garcia, Arnau; Gomis-González, Maria; Srivastava, Raj Kamal; Cutando, Laura; Ortega-Alvaro, Antonio; Ruehle, Sabine; Remmers, Floortje; Bindila, Laura; Bellocchio, Luigi; Marsicano, Giovanni; Lutz, Beat; Maldonado, Rafael

    2016-01-01

    Stressful events can generate emotional memories linked to the traumatic incident, but they also can impair the formation of nonemotional memories. Although the impact of stress on emotional memories is well studied, much less is known about the influence of the emotional state on the formation of nonemotional memories. We used the novel object-recognition task as a model of nonemotional memory in mice to investigate the underlying mechanism of the deleterious effect of stress on memory consolidation. Systemic, hippocampal, and peripheral blockade of cannabinoid type-1 (CB1) receptors abolished the stress-induced memory impairment. Genetic deletion and rescue of CB1 receptors in specific cell types revealed that the CB1 receptor population specifically in dopamine β-hydroxylase (DBH)-expressing cells is both necessary and sufficient for stress-induced impairment of memory consolidation, but CB1 receptors present in other neuronal populations are not involved. Strikingly, pharmacological manipulations in mice expressing CB1 receptors exclusively in DBH+ cells revealed that both hippocampal and peripheral receptors mediate the impact of stress on memory consolidation. Thus, CB1 receptors on adrenergic and noradrenergic cells provide previously unrecognized cross-talk between central and peripheral mechanisms in the stress-dependent regulation of nonemotional memory consolidation, suggesting new potential avenues for the treatment of cognitive aspects on stress-related disorders. PMID:27528659

  19. Impairment of fear memory consolidation and expression by antihistamines.

    Science.gov (United States)

    Nonaka, Ayako; Masuda, Fumitaka; Nomura, Hiroshi; Matsuki, Norio

    2013-02-01

    Antihistamines are widely used to treat allergy symptoms. First-generation antihistamines have adverse effects on the central nervous system (CNS), such as hypnotic and amnesic effects, whereas second-generation antihistamines have poor brain penetration, and therefore, have fewer CNS-related adverse effects. Memory consists of several phases, including acquisition, consolidation, expression, and extinction. It remains unclear whether these phases are affected by antihistamines. We investigated the effects of diphenhydramine, a first-generation antihistamine, and levocetirizine and olopatadine, second-generation antihistamines, on memory phases. Mice were subjected to fear conditioning on day 1 and tested on day 2. Antihistamines were administered before conditioning, immediately after conditioning, or before the test session. Diphenhydramine (30mg/kg) decreased freezing time when administered immediately after conditioning or before the test session. These effects were not attributable to a change in locomotor activity. Levocetirizine (0.1, 1, 10mg/kg) and olopatadine (1, 10, 20mg/kg) had no effects on conditioned fear. We also examined the effect of diphenhydramine and levocetirizine on the expression of an activity-dependent gene associated with the test session. Diphenhydramine, but not levocetirizine, increased Arc transcription in the central nucleus of the amygdala. These data indicate that diphenhydramine, but not levocetirizine or olopatadine, impairs the consolidation and expression of conditioned fear.

  20. One-dimensional consolidation of over-consolidated soil under time-dependent loading

    Institute of Scientific and Technical Information of China (English)

    Kanghe XIE; Kun WANG; Guohong CHEN; Anfeng HU

    2008-01-01

    The problem of one-dimensional consolidation of over-consolidated saturated soil under time-dependent loading was studied based on semi-analytical method. The relevant computer code was developed by FORTRAN programming, and one-dimensional consolidation behavior of over-consolidated soil was investigated. It is shown that, unlike this described by traditional Terzaghi's consolidation theory, the rate of excess pore water pressure dissipation is different from that of settlement developing. The magnitude of load and that of pre-consolidation pressure as well as the loading rate has all significant influence on consolidation. With the increasing of pre-consolidation pressure and loading rate, the rate of consolidation increases correspondingly. However, an increase in load will slow down the consolidation rate.

  1. Delayed working memory consolidation during the attentional blink.

    Science.gov (United States)

    Vogel, Edward K; Luck, Steven J

    2002-12-01

    After the detection of a target (T1) in a rapid stream of visual stimuli, there is a period of 400-600 msec during which a subsequent target (T2) is missed. This impairment in performance has been labeled the attentional blink. Recent theories propose that the attentional blink reflects a bottleneck in working memory consolidation such that T2 cannot be consolidated until after T1 is consolidated, and T2 is therefore masked by subsequent stimuli if it is presented while T1 is being consolidated. In support of this explanation, Giesbrecht & Di Lollo (1998) found that when T2 is the final item in the stimulus stream, no attentional blink is observed, because there are no subsequent stimuli that might mask T2. To provide a direct test of this explanation of the attentional blink, in the present study we used the P3 component of the event-related potential waveform to track the processing of T2. When T2 was followed by a masking item, we found that the P3 wave was completely suppressed during the attentional blink period, indicating that T2 was not consolidated in working memory. When T2 was the last item in the stimulus stream, however, we found that the P3 wave was delayed but not suppressed, indicating that T2 consolidation was not eliminated but simply delayed. These results are consistent with a fundamental limit on the consolidation of information in working memory.

  2. Autobiographical memory and hyperassociativity in the dreaming brain: implications for memory consolidation in sleep

    Science.gov (United States)

    Horton, Caroline L.; Malinowski, Josie E.

    2015-01-01

    In this paper we argue that autobiographical memory (AM) activity across sleep and wake can provide insight into the nature of dreaming, and vice versa. Activated memories within the sleeping brain reflect one’s personal life history (autobiography). They can appear in largely fragmentary forms and differ from conventional manifestations of episodic memory. Autobiographical memories in dreams can be sampled from non-REM as well as REM periods, which contain fewer episodic references and become more bizarre across the night. Salient fragmented memory features are activated in sleep and re-bound with fragments not necessarily emerging from the same memory, thus de-contextualizing those memories and manifesting as experiences that differ from waking conceptions. The constructive nature of autobiographical recall further encourages synthesis of these hyper-associated images into an episode via recalling and reporting dreams. We use a model of AM to account for the activation of memories in dreams as a reflection of sleep-dependent memory consolidation processes. We focus in particular on the hyperassociative nature of AM during sleep. PMID:26191010

  3. Sleep-dependent consolidation of value-based learning.

    Science.gov (United States)

    Baran, Bengi; Daniels, Dasha; Spencer, Rebecca M C

    2013-01-01

    It has been suggested that sleep selectively enhances memories with future relevance. Given that sleep's benefits can vary by item within a learning context, the present study investigated whether the amount of sleep-dependent consolidation may vary across items based on the value of the to-be-learned material. For this purpose, we used a value-based learning paradigm in which participants studied words paired with point values. There were two groups; participants either studied the words in the evening and were tested after a 12 hr interval containing a full night of sleep, or studied the words in the morning and were tested after 12 hr of continuous daytime wake. Free recall (F(1,36) = 19.35, pvalue for sleep and wake groups (p = .74). Thus, while encoding may vary with the value of the to-be-learned item, sleep-dependent consolidation does not.

  4. Schema-conformant memories are preferentially consolidated during REM sleep.

    Science.gov (United States)

    Durrant, Simon J; Cairney, Scott A; McDermott, Cathal; Lewis, Penelope A

    2015-07-01

    Memory consolidation is most commonly described by the standard model, which proposes an initial binding role for the hippocampus which diminishes over time as intracortical connections are strengthened. Recent evidence suggests that slow wave sleep (SWS) plays an essential role in this process. Existing animal and human studies have suggested that memories which fit tightly into an existing knowledge framework or schema might use an alternative consolidation route in which the medial prefrontal cortex takes on the binding role. In this study we sought to investigate the role of sleep in this process using a novel melodic memory task. Participants were asked to remember 32 melodies, half of which conformed to a tonal schema present in all enculturated listeners, and half of which did not fit with this schema. After a 24-h consolidation interval, participants were asked to remember a further 32 melodies, before being given a recognition test in which melodies from both sessions were presented alongside some previously unheard foils. Participants remembered schema-conformant melodies better than non-conformant ones. This was much more strongly the case for consolidated melodies, suggesting that consolidation over a 24-h period preferentially consolidated schema-conformant items. Overnight sleep was monitored between the sessions, and the extent of the consolidation benefit for schema-conformant items was associated with both the amount of REM sleep obtained and EEG theta power in frontal and central regions during REM sleep. Overall our data suggest that REM sleep plays a crucial role in the rapid consolidation of schema-conformant items. This finding is consistent with previous results from animal studies and the SLIMM model of Van Kesteren, Ruiter, Fernández, and Henson (2012), and suggest that REM sleep, rather than SWS, may be involved in an alternative pathway of consolidation for schema-conformant memories.

  5. Low acetylcholine during slow-wave sleep is critical for declarative memory consolidation

    OpenAIRE

    Gais, Steffen; Born, Jan

    2004-01-01

    The neurotransmitter acetylcholine is considered essential for proper functioning of the hippocampus-dependent declarative memory system, and it represents a major neuropharmacological target for the treatment of memory deficits, such as those in Alzheimer's disease. During slow-wave sleep (SWS), however, declarative memory consolidation is particularly strong, while acetylcholine levels in the hippocampus drop to a minimum. Observations in rats led to the hypothesis that the low cholinergic ...

  6. Sleep Spindle Density Predicts the Effect of Prior Knowledge on Memory Consolidation.

    Science.gov (United States)

    Hennies, Nora; Lambon Ralph, Matthew A; Kempkes, Marleen; Cousins, James N; Lewis, Penelope A

    2016-03-30

    Information that relates to a prior knowledge schema is remembered better and consolidates more rapidly than information that does not. Another factor that influences memory consolidation is sleep and growing evidence suggests that sleep-related processing is important for integration with existing knowledge. Here, we perform an examination of how sleep-related mechanisms interact with schema-dependent memory advantage. Participants first established a schema over 2 weeks. Next, they encoded new facts, which were either related to the schema or completely unrelated. After a 24 h retention interval, including a night of sleep, which we monitored with polysomnography, participants encoded a second set of facts. Finally, memory for all facts was tested in a functional magnetic resonance imaging scanner. Behaviorally, sleep spindle density predicted an increase of the schema benefit to memory across the retention interval. Higher spindle densities were associated with reduced decay of schema-related memories. Functionally, spindle density predicted increased disengagement of the hippocampus across 24 h for schema-related memories only. Together, these results suggest that sleep spindle activity is associated with the effect of prior knowledge on memory consolidation. Episodic memories are gradually assimilated into long-term memory and this process is strongly influenced by sleep. The consolidation of new information is also influenced by its relationship to existing knowledge structures, or schemas, but the role of sleep in such schema-related consolidation is unknown. We show that sleep spindle density predicts the extent to which schemas influence the consolidation of related facts. This is the first evidence that sleep is associated with the interaction between prior knowledge and long-term memory formation. Copyright © 2016 Hennies et al.

  7. Post-training meditation promotes motor memory consolidation

    Directory of Open Access Journals (Sweden)

    Maarten A Immink

    2016-11-01

    Full Text Available Following training, motor memory consolidation is thought to involve either memory stabilization or off-line learning processes. The extent to which memory stabilization or off-line learning relies on post-training wakeful periods or sleep is not clear and thus, novel research approaches are needed to further explore the conditions that promote motor memory consolidation. The present experiment represents the first empirical test of meditation as potential facilitator of motor memory consolidation. Twelve adult residents of a yoga center with a mean of nine years meditation experience were trained on a sequence key pressing task. Three hours after training, the meditation group completed a 30 minute session of yoga nidra meditation while a control group completed 30 minutes of light work duties. A wakeful period of 4.5 hours followed meditation after which participants completed a test involving both trained and untrained sequences. Training performance did not significantly differ between groups. Comparison of group performance at test, revealed a performance benefit of post-training meditation but this was limited to trained sequences only. That the post-training meditation performance benefit was specific to trained sequences is consistent with the notion of meditation promoting motor memory consolidation as opposed to general motor task performance benefits from meditation. Further, post-training meditation appears to have promoted motor memory stabilization as opposed to off-line learning. These findings represent the first demonstration of meditation related motor memory consolidation and are consistent with a growing body of literature demonstrating the benefits of meditation for cognitive function, including memory.

  8. Post-training Meditation Promotes Motor Memory Consolidation

    Science.gov (United States)

    Immink, Maarten A.

    2016-01-01

    Following training, motor memory consolidation is thought to involve either memory stabilization or off-line learning processes. The extent to which memory stabilization or off-line learning relies on post-training wakeful periods or sleep is not clear and thus, novel research approaches are needed to further explore the conditions that promote motor memory consolidation. The present experiment represents the first empirical test of meditation as potential facilitator of motor memory consolidation. Twelve adult residents of a yoga center with a mean of 9 years meditation experience were trained on a sequence key pressing task. Three hours after training, the meditation group completed a 30 min session of yoga nidra meditation while a control group completed 30 min of light work duties. A wakeful period of 4.5 h followed meditation after which participants completed a test involving both trained and untrained sequences. Training performance did not significantly differ between groups. Comparison of group performance at test, revealed a performance benefit of post-training meditation but this was limited to trained sequences only. That the post-training meditation performance benefit was specific to trained sequences is consistent with the notion of meditation promoting motor memory consolidation as opposed to general motor task performance benefits from meditation. Further, post-training meditation appears to have promoted motor memory stabilization as opposed to off-line learning. These findings represent the first demonstration of meditation related motor memory consolidation and are consistent with a growing body of literature demonstrating the benefits of meditation for cognitive function, including memory. PMID:27847492

  9. Sleep deprivation impairs consolidation of cued fear memory in rats.

    Directory of Open Access Journals (Sweden)

    Tankesh Kumar

    Full Text Available Post-learning sleep facilitates negative memory consolidation and also helps preserve it over several years. It is believed, therefore, that sleep deprivation may help prevent consolidation of fearful memory. Its effect, however, on consolidation of negative/frightening memories is not known. Cued fear-conditioning (CuFC is a widely used model to understand the neural basis of negative memory associated with anxiety disorders. In this study, we first determined the suitable circadian timing for consolidation of CuFC memory and changes in sleep architecture after CuFC. Thereafter, we studied the effect of sleep deprivation on CuFC memory consolidation. Three sets of experiments were performed in male Wistar rat (n=51. In experiment-I, animals were conditioned to cued-fear by presenting ten tone-shock paired stimuli during lights-on (7 AM (n=9 and lights-off (7 PM (n=9 periods. In experiment-II, animals were prepared for polysomnographic recording (n=8 and changes in sleep architecture after CuFC was determined. Further in experiment-III, animals were cued fear-conditioned during the lights-off period and were randomly divided into four groups: Sleep-Deprived (SD (n=9, Non-Sleep Deprived (NSD (n=9, Stress Control (SC (n=9 and Tone Control (n=7. Percent freezing amount, a hallmark of fear, was compared statistically in these groups. Rats trained during the lights-off period exhibited significantly more freezing compared to lights-on period. In CuFC trained animals, total sleep amount did not change, however, REM sleep decreased significantly. Further, out of total sleep time, animals spent proportionately more time in NREM sleep. Nevertheless, SD animals exhibited significantly less freezing compared to NSD and SC groups. These data suggest that sleep plays an important role in the consolidation of cued fear-conditioned memory.

  10. Consolidation differentially modulates schema effects on memory for items and associations.

    Directory of Open Access Journals (Sweden)

    Marlieke T R van Kesteren

    Full Text Available Newly learned information that is congruent with a preexisting schema is often better remembered than information that is incongruent. This schema effect on memory has previously been associated to more efficient encoding and consolidation mechanisms. However, this effect is not always consistently supported in the literature, with differential schema effects reported for different types of memory, different retrieval cues, and the possibility of time-dependent effects related to consolidation processes. To examine these effects more directly, we tested participants on two different types of memory (item recognition and associative memory for newly encoded visuo-tactile associations at different study-test intervals, thus probing memory retrieval accuracy for schema-congruent and schema-incongruent items and associations at different time points (t = 0, t = 20, and t = 48 hours after encoding. Results show that the schema effect on visual item recognition only arises after consolidation, while the schema effect on associative memory is already apparent immediately after encoding, persisting, but getting smaller over time. These findings give further insight into different factors influencing the schema effect on memory, and can inform future schema experiments by illustrating the value of considering effects of memory type and consolidation on schema-modulated retrieval.

  11. Sleep and cortisol interact to support memory consolidation.

    Science.gov (United States)

    Bennion, Kelly A; Mickley Steinmetz, Katherine R; Kensinger, Elizabeth A; Payne, Jessica D

    2015-03-01

    Separate lines of research have demonstrated that rises in cortisol can benefit memory consolidation, as can the occurrence of sleep soon after encoding. For the first time, we demonstrate that pre-learning cortisol interacts with sleep to benefit memory consolidation, particularly for negative arousing items. Resting cortisol levels during encoding were positively correlated with subsequent memory, but only following a period of sleep. There was no such relation following a period of wakefulness. Using eye tracking, we further reveal that for negative stimuli, this facilitative effect may arise because cortisol strengthens the relationship between looking time at encoding and subsequent memory. We suggest that elevated cortisol may "tag" attended information as important to remember at the time of encoding, thus enabling sleep-based processes to optimally consolidate salient information in a selective manner. Neuroimaging data suggest that this optimized consolidation leads to a refinement of the neural processes recruited for successful retrieval of negative stimuli, with the retrieval of items attended in the presence of elevated cortisol and consolidated over a night of sleep associated with activity in the amygdala and vmPFC.

  12. Fear Extinction Memory Consolidation Requires Potentiation of Pontine-Wave Activity during REM Sleep

    Science.gov (United States)

    Datta, Subimal; O'Malley, Matthew W .

    2013-01-01

    Sleep plays an important role in memory consolidation within multiple memory systems including contextual fear extinction memory, but little is known about the mechanisms that underlie this process. Here, we show that fear extinction training in rats, which extinguished conditioned fear, increased both slow-wave sleep and rapid-eye movement (REM) sleep. Surprisingly, 24 h later, during memory testing, only 57% of the fear-extinguished animals retained fear extinction memory. We found that these animals exhibited an increase in phasic pontine-wave (P-wave) activity during post-training REM sleep, which was absent in the 43% of animals that failed to retain fear extinction memory. The results of this study provide evidence that brainstem activation, specifically potentiation of phasic P-wave activity, during post-training REM sleep is critical for consolidation of fear extinction memory. The results of this study also suggest that, contrary to the popular hypothesis of sleep and memory, increased sleep after training alone does not guarantee consolidation and/or retention of fear extinction memory. Rather, the potentiation of specific sleep-dependent physiological events may be a more accurate predictor for successful consolidation of fear extinction memory. Identification of this unique mechanism will significantly improve our present understanding of the cellular and molecular mechanisms that underlie the sleep-dependent regulation of emotional memory. Additionally, this discovery may also initiate development of a new, more targeted treatment method for clinical disorders of fear and anxiety in humans that is more efficacious than existing methods such as exposure therapy that incorporate only fear extinction. PMID:23467372

  13. Fear extinction memory consolidation requires potentiation of pontine-wave activity during REM sleep.

    Science.gov (United States)

    Datta, Subimal; O'Malley, Matthew W

    2013-03-06

    Sleep plays an important role in memory consolidation within multiple memory systems including contextual fear extinction memory, but little is known about the mechanisms that underlie this process. Here, we show that fear extinction training in rats, which extinguished conditioned fear, increased both slow-wave sleep and rapid-eye movement (REM) sleep. Surprisingly, 24 h later, during memory testing, only 57% of the fear-extinguished animals retained fear extinction memory. We found that these animals exhibited an increase in phasic pontine-wave (P-wave) activity during post-training REM sleep, which was absent in the 43% of animals that failed to retain fear extinction memory. The results of this study provide evidence that brainstem activation, specifically potentiation of phasic P-wave activity, during post-training REM sleep is critical for consolidation of fear extinction memory. The results of this study also suggest that, contrary to the popular hypothesis of sleep and memory, increased sleep after training alone does not guarantee consolidation and/or retention of fear extinction memory. Rather, the potentiation of specific sleep-dependent physiological events may be a more accurate predictor for successful consolidation of fear extinction memory. Identification of this unique mechanism will significantly improve our present understanding of the cellular and molecular mechanisms that underlie the sleep-dependent regulation of emotional memory. Additionally, this discovery may also initiate development of a new, more targeted treatment method for clinical disorders of fear and anxiety in humans that is more efficacious than existing methods such as exposure therapy that incorporate only fear extinction.

  14. Endogenous cannabinoid release within prefrontal-limbic pathways affects memory consolidation of emotional training

    NARCIS (Netherlands)

    Morena, M.; Roozendaal, B.; Trezza, V.; Ratano, P.; Peloso, A.; Hauer, D.; Atsak, P.; Trabace, L.; Cuomo, V.; McGaugh, J.L.; Schelling, G.; Campolongo, P.

    2014-01-01

    Previous studies have provided extensive evidence that administration of cannabinoid drugs after training modulates the consolidation of memory for an aversive experience. The present experiments investigated whether the memory consolidation is regulated by endogenously released cannabinoids. The ex

  15. Cerebellar vermis H₂ receptors mediate fear memory consolidation in mice.

    Science.gov (United States)

    Gianlorenço, A C L; Riboldi, A M; Silva-Marques, B; Mattioli, R

    2015-02-01

    Histaminergic fibers are present in the molecular and granular layers of the cerebellum and have a high density in the vermis and flocullus. Evidence supports that the cerebellar histaminergic system is involved in memory consolidation. Our recent study showed that histamine injections facilitate the retention of an inhibitory avoidance task, which was abolished by pretreatment with an H2 receptor antagonist. In the present study, we investigated the effects of intracerebellar post training injections of H1 and H2 receptor antagonists as well as the selective H2 receptor agonist on fear memory consolidation. The cerebellar vermi of male mice were implanted with guide cannulae, and after three days of recovery, the inhibitory avoidance test was performed. Immediately after a training session, animals received a microinjection of the following histaminergic drugs: experiment 1, saline or chlorpheniramine (0.016, 0.052 or 0.16 nmol); experiment 2, saline or ranitidine (0.57, 2.85 or 5.07 nmol); and experiment 3, saline or dimaprit (1, 2 or 4 nmol). Twenty-four hours later, a retention test was performed. The data were analyzed using one-way analysis of variance (ANOVA) and Duncan's tests. Animals microinjected with chlorpheniramine did not show any behavioral effects at the doses that we used. Intra-cerebellar injection of the H2 receptor antagonist ranitidine inhibited, while the selective H2 receptor agonist dimaprit facilitated, memory consolidation, suggesting that H2 receptors mediate memory consolidation in the inhibitory avoidance task in mice.

  16. Memory consolidation effects on memory stabilization and item integration in older adults.

    Science.gov (United States)

    Brown, Helen; Maylor, Elizabeth A

    2016-11-23

    This study examined the differential effects of aging on consolidation processes that strengthen newly acquired memory traces in veridical form (memory stabilization) versus consolidation processes that are responsible for integrating these memory traces into an existing body of knowledge (item integration). Older adults learned 13 nonwords and were tested on their memory for the nonwords, and on whether these nonwords impacted upon processing of similar-sounding English words immediately and 24 hours later. Participants accurately recognized the nonwords immediately, but showed significant decreases in delayed recognition and recall. In comparison, the nonwords impacted upon processing of similar-sounding words only in the delayed test. Together, these findings suggest that memory consolidation processes may be more evident in item integration than memory stabilization processes for new declarative memories in older adults.

  17. Laugh yourself to sleep: memory consolidation for humorous information.

    Science.gov (United States)

    Chambers, Alexis M; Payne, Jessica D

    2014-05-01

    There is extensive evidence that emotional information is better remembered than neutral information across long delays, especially if the delay interval contains an opportunity for sleep. However, as prior studies have focused on memory for negative stimuli, it is unclear whether positive memories benefit from time and sleep as well. To investigate the consolidation of positive memories, the current study examined differences in memory for humorous and non-humorous cartoons. While prior evidence demonstrates that humorous information is preferentially remembered relative to non-humorous information over brief delays, it is unknown whether this benefit lasts across longer delay intervals or whether sleep is important for lasting humor memories to form. Thus, we tested memory for 27 cartoons across 12-h delay periods containing either sleep or wakefulness. Results indicate that humor's enhancing effect on recall memory is robust across a 12-h delay and that a period of sleep facilitates this effect over wakefulness when cartoons are novel to participants and ranked based on subjective emotional ratings. Further, in accordance with previous studies that reveal diminished emotional reactivity to stimuli following sleep, in a supplemental experiment, we found that sleep reduced subjective ratings of humor, arousal, and positivity of humorous cartoons. These findings provide preliminary evidence that sleep's impact on negative emotional memory consolidation and emotional reactivity can be extended to positive stimuli as well.

  18. System Consolidation of Spatial Memories in Mice: Effects of Enriched Environment

    Directory of Open Access Journals (Sweden)

    Joyce Bonaccorsi

    2013-01-01

    Full Text Available Environmental enrichment (EE is known to enhance learning and memory. Declarative memories are thought to undergo a first rapid and local consolidation process, followed by a prolonged process of system consolidation, which consist in a time-dependent gradual reorganization of brain regions supporting remote memory storage and crucial for the formation of enduring memories. At present, it is not known whether EE can affect the process of declarative memory system consolidation. We characterized the time course of hippocampal and cortical activation following recall of progressively more remote spatial memories. Wild-type mice either exposed to EE for 40 days or left in standard environment were subjected to spatial learning in the Morris water maze and to the probe test 1, 10, 20, 30, and 50 days after learning. Following the probe test, regional expression of the inducible immediate early gene c-Fos was mapped by immunohistochemistry, as an indicator of neuronal activity. We found that activation of the medial prefrontal cortex (mPFC, suggested to have a privileged role in processing remote spatial memories, was evident at shorter time intervals after learning in EE mice; in addition, EE induced the progressive activation of a distributed cortical network not activated in non-EE mice. This suggests that EE not only accelerates the process of mPFC recruitment but also recruits additional cortical areas into the network supporting remote spatial memories.

  19. The role of sleep in declarative memory consolidation--direct evidence by intracranial EEG.

    NARCIS (Netherlands)

    Axmacher, N.; Haupt, S.; Fernandez, G.S.E.; Elger, C.E.; Fell, J.

    2008-01-01

    Two step theories of memory formation assume that an initial learning phase is followed by a consolidation stage. Memory consolidation has been suggested to occur predominantly during sleep. Very recent findings, however, suggest that important steps in memory consolidation occur also during waking

  20. Stress enhances the consolidation of extinction memory in a predictive learning task

    Directory of Open Access Journals (Sweden)

    Tanja eHamacher-Dang

    2013-08-01

    Full Text Available Extinction is not always permanent, as indicated by several types of recovery effects, such as the renewal effect, which may occur after a context change and points towards the importance of contextual cues. Strengthening the retrieval of extinction memory is a crucial aim of extinction-based psychotherapeutic treatments of anxiety disorders to prevent relapse. Stress is known to modulate learning and memory, with mostly enhancing effects on memory consolidation. However, whether such a consolidation-enhancing effect of acute stress can also be found for extinction memory has not yet been examined in humans. In this study, we investigated the effect of stress after extinction learning on the retrieval of extinction memory in a predictive learning renewal paradigm. Participants took the part of being the doctor of a fictitious patient and learned to predict whether certain food stimuli were associated with ‘stomach trouble’ in two different restaurants (contexts. On the first day, critical stimuli were associated with stomach trouble in context A (acquisition phase. On the second day, these associations were extinguished in context B. Directly after extinction, participants were either exposed to a stressor (socially evaluated cold pressor test; n = 22 or a control condition (n = 24. On the third day, we tested retrieval of critical associations in contexts A and B. Participants exposed to stress after extinction exhibited a reduced recovery of responding at test in context B, suggesting that stress may context-dependently enhance the consolidation of extinction memory. Furthermore, the increase in cortisol in response to the stressor was negatively correlated with the recovery of responding in context A. Our findings suggest that in parallel to the known effects of stress on the consolidation of episodic memory, stress also enhances the consolidation of extinction memory, which might be relevant for potential applications in extinction

  1. Alternative conceptions of memory consolidation and the role of the hippocampus at the systems level in rodents.

    Science.gov (United States)

    Sutherland, R J; Lehmann, H

    2011-06-01

    We discuss very recent experiments with rodents addressing the idea that long-term memories initially depending on the hippocampus, over a prolonged period, become independent of it. No unambiguous recent evidence exists to substantiate that this occurs. Most experiments find that recent and remote memories are equally affected by hippocampus damage. Nearly all experiments that report spared remote memories suffer from two problems: retrieval could be based upon substantial regions of spared hippocampus and recent memory is tested at intervals that are of the same order of magnitude as cellular consolidation. Accordingly, we point the way beyond systems consolidation theories, both the Standard Model of Consolidation and the Multiple Trace Theory, and propose a simpler multiple storage site hypothesis. On this view, with event reiterations, different memory representations are independently established in multiple networks. Many detailed memories always depend on the hippocampus; the others may be established and maintained independently.

  2. Acute Exercise and Motor Memory Consolidation

    DEFF Research Database (Denmark)

    Thomas, Richard

    It is well documented in the scientific literature that acute and chronic exercise positively affects cognitive function and brain health in humans. It has also been shown more recently that acute aerobic exercise can improve the acquisition and retention of motor skills. While this has interesting...... of exercise intensity, timing and type on the consolidation of visuomotor skill learning, to obtain further understanding of the behavioral effects and underlying mechanisms. Study I focused on the role of exercise intensity and included a low (EX45: 45% Wmax) and high (EX90: 90% Wmax) intensity aerobic...... scores. Study II focused on the role of exercise timing and included the CON and EX90 groups from study I. Two additional high intensity exercise groups were included performing the cycling bout at 1h (EX90+1) and 2h (EX90+2) post motor skill acquisition. Results showed that the positive effect...

  3. The effect of exogenous cortisol during sleep on the behavioral and neural correlates of emotional memory consolidation in humans.

    Science.gov (United States)

    van Marle, Hein J F; Hermans, Erno J; Qin, Shaozheng; Overeem, Sebastiaan; Fernández, Guillén

    2013-09-01

    A host of animal work demonstrates that the retention benefit for emotionally aversive over neutral memories is regulated by glucocorticoid action during memory consolidation. Particularly, glucocorticoids may affect systems-level processes that promote the gradual reorganization of emotional memory traces. These effects remain largely uninvestigated in humans. Therefore, in this functional magnetic resonance imaging study we administered hydrocortisone during a polysomnographically monitored night of sleep directly after healthy volunteers studied negative and neutral pictures in a double-blind, placebo-controlled, between-subjects design. The following evening memory consolidation was probed during a recognition memory test in the MR scanner by assessing the difference in brain activity associated with memory for the consolidated items studied before sleep and new, unconsolidated items studied shortly before test (remote vs. recent memory paradigm). Hydrocortisone administration resulted in elevated cortisol levels throughout the experimental night with no group difference at recent encoding or test. Behaviorally, we showed that cortisol enhanced the difference between emotional and neutral consolidated memory, effectively prioritizing emotional memory consolidation. On a neural level, we found that cortisol reduced amygdala reactivity related to the retrieval of these same consolidated, negative items. These findings show that cortisol administration during first post-encoding sleep had a twofold effect on the first 24h of emotional memory consolidation. While cortisol prioritized recognition memory for emotional items, it reduced reactivation of the neural circuitry underlying emotional responsiveness during retrieval. These findings fit recent theories on emotional depotentiation following consolidation during sleep, although future research should establish the sleep-dependence of this effect. Moreover, our data may shed light on mechanisms underlying

  4. Robust hippocampal responsivity during retrieval of consolidated associative memory.

    Science.gov (United States)

    Hattori, Shoai; Chen, Lillian; Weiss, Craig; Disterhoft, John F

    2015-05-01

    A contentious point in memory research is whether or not the hippocampus plays a time-limited role in the consolidation of declarative memories. A widely held view is that declarative memories are initially encoded in the hippocampus, then transferred to the neocortex for long-term storage. Alternate views argue instead that the hippocampus continues to play a role in remote memory recall. These competing theories are largely based on human amnesic and animal lesion/inactivation studies. However, in vivo electrophysiological evidence supporting these views is scarce. Given that other studies examining the role of the hippocampus in remote memory retrieval using lesion and imaging techniques in human and animal models have provided mixed results, it would be particularly useful to gain insight at the in vivo electrophysiological level. Here we report hippocampal single-neuron and theta activity recorded longitudinally during acquisition and remote retrieval of trace eyeblink conditioning. Results from conditioned rabbits were compared to those obtained from yoked pseudo-conditioned control rabbits. Results reveal continued learning-specific hippocampal activity one month after initial acquisition of the task. Our findings yield insight into the normal physiological responses of the hippocampus during memory processes and provide compelling in vivo electrophysiological evidence that the hippocampus is involved in both acquisition and retrieval of consolidated memories. © 2014 The Authors Hippocampus Published by Wiley Periodicals, Inc.

  5. Effects of bilateral reversible inactivation of Accumbens Nucleus on acquisition and consolidation of memory in rats

    Directory of Open Access Journals (Sweden)

    Abbas Ali Vafaee

    2003-09-01

    Full Text Available Extensive evidence indicates that the Accumbens Nucleus (AN probably involved in emotional memory. The present work investigated possible of AN involvement on acquisition and consolidation memory in passive avoidance learning (PAL task. This is experimental research and during that Albino male Wistar rats (n=80 were surgically implanted bilaterally with cannulae aimed at the AN were trained to PAL task. They received one trial PAL (1 ma 1.5 s footshock. Retention was tested 2 days after training. Lidocaine 2% (0.6 µl/side 20 min before of training for assessment of acquisition and Tetrodotoxine (5ng/0.6ml/side immediately, 60 and 120 min after training for assessment of consolidation were used to temporarily inactivate the AN. Control rats were injected with the same volume of saline. The data indicate that bilateral inactivation of AN immediately and 60 min after training significantly impaired consolidation of memory (P0.05. These results suggest that AN make contribution and involvement of long term memory and may be more important to the consolidation (time dependent of memory for the PAL.

  6. The Nature of Short-Term Consolidation in Visual Working Memory.

    Science.gov (United States)

    Ricker, Timothy J; Hardman, Kyle O

    2017-07-13

    Short-term consolidation is the process by which stable working memory representations are created. This process is fundamental to cognition yet poorly understood. The present work examines short-term consolidation using a Bayesian hierarchical model of visual working memory recall to determine the underlying processes at work. Our results show that consolidation functions largely through changing the proportion of memory items successfully maintained until test. Although there was some evidence that consolidation affects representational precision, this change was modest and could not account for the bulk of the consolidation effect on memory performance. The time course of the consolidation function and selective influence of consolidation on specific serial positions strongly indicates that short-term consolidation induces an attentional blink. The blink leads to deficits in memory for the immediately following item when time pressure is introduced. Temporal distinctiveness accounts of the consolidation process are tested and ruled out. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Early versus late-phase consolidation of opiate reward memories requires distinct molecular and temporal mechanisms in the amygdala-prefrontal cortical pathway.

    Directory of Open Access Journals (Sweden)

    Shervin Gholizadeh

    Full Text Available The consolidation of newly acquired memories involves the temporal transition from a recent, less stable trace to a more permanent consolidated form. Opiates possess potent rewarding effects and produce powerful associative memories. The activation of these memories is associated with opiate abuse relapse phenomena and the persistence of compulsive opiate dependence. However, the neuronal, molecular and temporal mechanisms by which associative opiate reward memories are consolidated are not currently understood. We report that the consolidation of associative opiate reward memories involves a temporal and molecular switch between the basolateral nucleus of the amygdala (BLA (early consolidation phase to the medial prefrontal cortex (mPFC (late consolidation phase. We demonstrate at the molecular, behavioral and neuronal levels that the consolidation of a recently acquired opiate reward memory involves an extracellular signal-related kinase (ERK-dependent phosphorylation process within the BLA. In contrast, later-stage consolidation of a newly acquired memory is dependent upon a calcium-calmodulin-dependent (CaMKII, ERK-independent, mechanism in the mPFC, over a 12 hr temporal gradient. In addition, using in vivo multi-unit neuronal recordings in the mPFC, we report that protein synthesis within the BLA modulates the consolidation of opiate-reward memory in neuronal mPFC sub-populations, via the same temporal dynamic.

  8. Early versus late-phase consolidation of opiate reward memories requires distinct molecular and temporal mechanisms in the amygdala-prefrontal cortical pathway.

    Science.gov (United States)

    Gholizadeh, Shervin; Sun, Ninglei; De Jaeger, Xavier; Bechard, Melanie; Coolen, Lique; Laviolette, Steven R

    2013-01-01

    The consolidation of newly acquired memories involves the temporal transition from a recent, less stable trace to a more permanent consolidated form. Opiates possess potent rewarding effects and produce powerful associative memories. The activation of these memories is associated with opiate abuse relapse phenomena and the persistence of compulsive opiate dependence. However, the neuronal, molecular and temporal mechanisms by which associative opiate reward memories are consolidated are not currently understood. We report that the consolidation of associative opiate reward memories involves a temporal and molecular switch between the basolateral nucleus of the amygdala (BLA) (early consolidation phase) to the medial prefrontal cortex (mPFC) (late consolidation phase). We demonstrate at the molecular, behavioral and neuronal levels that the consolidation of a recently acquired opiate reward memory involves an extracellular signal-related kinase (ERK)-dependent phosphorylation process within the BLA. In contrast, later-stage consolidation of a newly acquired memory is dependent upon a calcium-calmodulin-dependent (CaMKII), ERK-independent, mechanism in the mPFC, over a 12 hr temporal gradient. In addition, using in vivo multi-unit neuronal recordings in the mPFC, we report that protein synthesis within the BLA modulates the consolidation of opiate-reward memory in neuronal mPFC sub-populations, via the same temporal dynamic.

  9. Memory Consolidation and Neural Substrate of Reward

    Directory of Open Access Journals (Sweden)

    Mañas, Mauro

    2012-08-01

    Full Text Available Prematurity is one of the most relevant health problems among children in the developed countries. Around 8 to 10% of children birth before the 37 week and/or with a very low birth weight (VLBW (1500 g. This causes 75% of the prenatal mortality and the 50% of the children disability. The aim of this study was to assess neuropsychological and emotional impairments in 7 year old children who were born VLBW. A clinical interview, the Children Neuropsychological Assessment Battery, and the Behavioral Assessment System for Children (BASC were administrated. VLBW children showed memory and executive function deficits, as well as, behavioral and attention problems. These results highlight the importance of long term follow up of the VLBW children and point out the necessity of developing adequate neuropsychological and emotional treatment program for these children.

  10. Behavioral and Neural Analysis of GABA in the Acquisition, Consolidation, Reconsolidation, and Extinction of Fear Memory

    Science.gov (United States)

    Makkar, Steve R; Zhang, Shirley Q; Cranney, Jacquelyn

    2010-01-01

    The current review systematically documents the role of γ-amino-butyric acid (GABA) in different aspects of fear memory—acquisition and consolidation, reconsolidation, and extinction, and attempts to resolve apparent contradictions in the data in order to identify the function of GABAA receptors in fear memory. First, numerous studies have shown that pre- and post-training administration of drugs that facilitate GABAergic transmission disrupt the initial formation of fear memories, indicating a role for GABAA receptors, possibly within the amygdala and hippocampus, in the acquisition and consolidation of fear memories. Similarly, recent evidence indicates that these drugs are also detrimental to the restorage of fear memories after their reactivation. This suggests a role for GABAA receptors in the reconsolidation of fear memories, although the precise neural circuits are yet to be identified. Finally, research regarding the role of GABA in extinction has shown that GABAergic transmission is also disruptive to the formation of newly acquired extinction memories. We argue that contradictions to these patterns are the result of variations in (a) the location of drug infusion, (b) the dosage of the drug and/or (c) the time point of drug administration. The question of whether these GABA-induced memory deficits reflect deficits in retrieval is discussed. Overall, the evidence implies that the processes mediating memory stability consequent to initial fear learning, memory reactivation, and extinction training are dependent on a common mechanism of reduced GABAergic neurotransmission. PMID:20410874

  11. Daytime sleep condenses the time course of motor memory consolidation.

    Science.gov (United States)

    Korman, Maria; Doyon, Julien; Doljansky, Julia; Carrier, Julie; Dagan, Yaron; Karni, Avi

    2007-09-01

    Two behavioral phenomena characterize human motor memory consolidation: diminishing susceptibility to interference by a subsequent experience and the emergence of delayed, offline gains in performance. A recent model proposes that the sleep-independent reduction in interference is followed by the sleep-dependent expression of offline gains. Here, using the finger-opposition sequence-learning task, we show that an interference experienced at 2 h, but not 8 h, following the initial training prevented the expression of delayed gains at 24 h post-training. However, a 90-min nap, immediately post-training, markedly reduced the susceptibility to interference, with robust delayed gains expressed overnight, despite interference at 2 h post-training. With no interference, a nap resulted in much earlier expression of delayed gains, within 8 h post-training. These results suggest that the evolution of robustness to interference and the evolution of delayed gains can coincide immediately post-training and that both effects reflect sleep-sensitive processes.

  12. Possibility of "superfast" consolidation of long-term memory.

    Science.gov (United States)

    Podolski IYa

    1998-01-01

    Two new behavioural tests in rats are described which demonstrate the fast consolidation of the long-term memory (LTM) in a dangerous natural situation (water escape). It is shown that after one-trial learning of the motor skill (jumping out of the water), long-term memory traces are retained without forgetting and are resistant to the blockade of M-cholinoreceptors by scopolamine (2 mg/kg) and of D1/D2 dopamine receptors by haloperidol (10 mg/kg) as well as electroconvulsive shock applied tank wall, learning of necessary motor skills, automatization and minimization of the skilled movements in 1.5-3.0 min, after 5 to 7 trials at two-second intervals (superfast learning) is demonstrated. It is suggested that the superfast consolidation of LTM (several minutes) is possible in life-threatening situations, the necessary time being 1-2 orders of magnitude less than it is generally accepted in the modern theories of memory. The proposed behavioural models may be helpful in investigation of some fundamental physiological and molecular mechanisms of stable neuronal interactions, as a basis for LTM consolidation.

  13. The Yin and Yang of Memory Consolidation: Hippocampal and Neocortical

    Science.gov (United States)

    Rossato, Janine I.; Jacobse, Justin; Grieves, Roddy M.; Spooner, Patrick A.; Battaglia, Francesco P.; Fernández, Guillen; Morris, Richard G. M.

    2017-01-01

    While hippocampal and cortical mechanisms of memory consolidation have long been studied, their interaction is poorly understood. We sought to investigate potential interactions with respect to trace dominance, strengthening, and interference associated with postencoding novelty or sleep. A learning procedure was scheduled in a watermaze that placed the impact of novelty and sleep in opposition. Distinct behavioural manipulations—context preexposure or interference during memory retrieval—differentially affected trace dominance and trace survival, respectively. Analysis of immediate early gene expression revealed parallel up-regulation in the hippocampus and cortex, sustained in the hippocampus in association with novelty but in the cortex in association with sleep. These findings shed light on dynamically interacting mechanisms mediating the stabilization of hippocampal and neocortical memory traces. Hippocampal memory traces followed by novelty were more dominant by default but liable to interference, whereas sleep engaged a lasting stabilization of cortical traces and consequent trace dominance after preexposure. PMID:28085883

  14. Acute exercise and motor memory consolidation: The role of exercise intensity and timing

    DEFF Research Database (Denmark)

    Thomas, Richard; Korsgaard Johnsen, Line; Geertsen, Svend Sparre

    2015-01-01

    Background A single bout of high intensity cycling (~90% VO2peak) immediately after motor skill training enhances motor memory consolidation. It is unclear how different parameters of exercise may influence this process and the underlying mechanisms are poorly understood. We hypothesize that the ...... tests were not related to measures of CSE at any time point indicating that further studies are necessary to understand the physiological mechanisms leading to improvements in motor memory relating to exercise.......Background A single bout of high intensity cycling (~90% VO2peak) immediately after motor skill training enhances motor memory consolidation. It is unclear how different parameters of exercise may influence this process and the underlying mechanisms are poorly understood. We hypothesize...... that the effects of exercise on consolidation are time-dependent with a decreasing positive effect of exercise post acquisition and investigate the role of exercise intensity and timing on motor memory consolidation. Furthermore, we explore the potential role of transient changes in corticospinal excitability (CSE...

  15. The NO-cGMP-PKG Signaling Pathway Regulates Synaptic Plasticity and Fear Memory Consolidation in the Lateral Amygdala via Activation of ERK/MAP Kinase

    Science.gov (United States)

    Ota, Kristie T.; Pierre, Vicki J.; Ploski, Jonathan E.; Queen, Kaila; Schafe, Glenn E.

    2008-01-01

    Recent studies have shown that nitric oxide (NO) signaling plays a crucial role in memory consolidation of Pavlovian fear conditioning and in synaptic plasticity in the lateral amygdala (LA). In the present experiments, we examined the role of the cGMP-dependent protein kinase (PKG), a downstream effector of NO, in fear memory consolidation and…

  16. Sleep modulates the neural substrates of both spatial and contextual memory consolidation.

    Directory of Open Access Journals (Sweden)

    Géraldine Rauchs

    Full Text Available It is known that sleep reshapes the neural representations that subtend the memories acquired while navigating in a virtual environment. However, navigation is not process-pure, as manifold learning components contribute to performance, notably the spatial and contextual memory constituents. In this context, it remains unclear whether post-training sleep globally promotes consolidation of all of the memory components embedded in virtual navigation, or rather favors the development of specific representations. Here, we investigated the effect of post-training sleep on the neural substrates of the consolidation of spatial and contextual memories acquired while navigating in a complex 3D, naturalistic virtual town. Using fMRI, we mapped regional cerebral activity during various tasks designed to tap either the spatial or the contextual memory component, or both, 72 h after encoding with or without sleep deprivation during the first post-training night. Behavioral performance was not dependent upon post-training sleep deprivation, neither in a natural setting that engages both spatial and contextual memory processes nor when looking more specifically at each of these memory representations. At the neuronal level however, analyses that focused on contextual memory revealed distinct correlations between performance and neuronal activity in frontal areas associated with recollection processes after post-training sleep, and in the parahippocampal gyrus associated with familiarity processes in sleep-deprived participants. Likewise, efficient spatial memory was associated with posterior cortical activity after sleep whereas it correlated with parahippocampal/medial temporal activity after sleep deprivation. Finally, variations in place-finding efficiency in a natural setting encompassing spatial and contextual elements were associated with caudate activity after post-training sleep, suggesting the automation of navigation. These data indicate that post

  17. [The molecular scenarios of the consolidation of long-term memory].

    Science.gov (United States)

    Anokhin, K V

    1997-01-01

    Long-term memory consolidation is a critical event in the transition of short-lasting experiences into durable modifications of behaviour. Present article focuses on the problem of molecular bases of this process. It starts with a brief review of biochemical and pharmacological data demonstrating a universal dependence of long-term memory on gene expression in the brain. Some of the experimental studies of immediate early gene expression in the brain during learning are described in the second part of the article. A hypothesis is discussed according to which consolidation of long-term memory employ the same biphasic molecular cascade of gene expression that is used for cell growth and differentiation during development.

  18. Endogenous cannabinoid release within prefrontal-limbic pathways affects memory consolidation of emotional training

    Science.gov (United States)

    Morena, Maria; Roozendaal, Benno; Trezza, Viviana; Ratano, Patrizia; Peloso, Andrea; Hauer, Daniela; Atsak, Piray; Trabace, Luigia; Cuomo, Vincenzo; McGaugh, James L.; Schelling, Gustav; Campolongo, Patrizia

    2014-01-01

    Previous studies have provided extensive evidence that administration of cannabinoid drugs after training modulates the consolidation of memory for an aversive experience. The present experiments investigated whether the memory consolidation is regulated by endogenously released cannabinoids. The experiments first examined whether the endocannabinoids anandamide (AEA) and 2-arachidonoyl glycerol (2-AG) are released by aversive training. Inhibitory avoidance training with higher footshock intensity produced increased levels of AEA in the amygdala, hippocampus, and medial prefrontal cortex (mPFC) shortly after training in comparison with levels assessed in rats trained with lower footshock intensity or unshocked controls exposed only to the training apparatus. In contrast, 2-AG levels were not significantly elevated. The additional finding that posttraining infusions of the fatty acid amide hydrolase (FAAH) inhibitor URB597, which selectively increases AEA levels at active synapses, administered into the basolateral complex of the amygdala (BLA), hippocampus, or mPFC enhanced memory strongly suggests that the endogenously released AEA modulates memory consolidation. Moreover, in support of the view that this emotional training-associated increase in endocannabinoid neurotransmission, and its effects on memory enhancement, depends on the integrity of functional interactions between these different brain regions, we found that disruption of BLA activity blocked the training-induced increases in AEA levels as well as the memory enhancement produced by URB597 administered into the hippocampus or mPFC. Thus, the findings provide evidence that emotionally arousing training increases AEA levels within prefrontal-limbic circuits and strongly suggest that this cannabinoid activation regulates emotional arousal effects on memory consolidation. PMID:25489086

  19. Epigenetic alterations are critical for fear memory consolidation and synaptic plasticity in the lateral amygdala.

    Directory of Open Access Journals (Sweden)

    Melissa S Monsey

    Full Text Available Epigenetic mechanisms, including histone acetylation and DNA methylation, have been widely implicated in hippocampal-dependent learning paradigms. Here, we have examined the role of epigenetic alterations in amygdala-dependent auditory Pavlovian fear conditioning and associated synaptic plasticity in the lateral nucleus of the amygdala (LA in the rat. Using Western blotting, we first show that auditory fear conditioning is associated with an increase in histone H3 acetylation and DNMT3A expression in the LA, and that training-related alterations in histone acetylation and DNMT3A expression in the LA are downstream of ERK/MAPK signaling. Next, we show that intra-LA infusion of the histone deacetylase (HDAC inhibitor TSA increases H3 acetylation and enhances fear memory consolidation; that is, long-term memory (LTM is enhanced, while short-term memory (STM is unaffected. Conversely, intra-LA infusion of the DNA methyltransferase (DNMT inhibitor 5-AZA impairs fear memory consolidation. Further, intra-LA infusion of 5-AZA was observed to impair training-related increases in H3 acetylation, and pre-treatment with TSA was observed to rescue the memory consolidation deficit induced by 5-AZA. In our final series of experiments, we show that bath application of either 5-AZA or TSA to amygdala slices results in significant impairment or enhancement, respectively, of long-term potentiation (LTP at both thalamic and cortical inputs to the LA. Further, the deficit in LTP following treatment with 5-AZA was observed to be rescued at both inputs by co-application of TSA. Collectively, these findings provide strong support that histone acetylation and DNA methylation work in concert to regulate memory consolidation of auditory fear conditioning and associated synaptic plasticity in the LA.

  20. Epigenetic alterations are critical for fear memory consolidation and synaptic plasticity in the lateral amygdala.

    Science.gov (United States)

    Monsey, Melissa S; Ota, Kristie T; Akingbade, Irene F; Hong, Ellie S; Schafe, Glenn E

    2011-01-01

    Epigenetic mechanisms, including histone acetylation and DNA methylation, have been widely implicated in hippocampal-dependent learning paradigms. Here, we have examined the role of epigenetic alterations in amygdala-dependent auditory Pavlovian fear conditioning and associated synaptic plasticity in the lateral nucleus of the amygdala (LA) in the rat. Using Western blotting, we first show that auditory fear conditioning is associated with an increase in histone H3 acetylation and DNMT3A expression in the LA, and that training-related alterations in histone acetylation and DNMT3A expression in the LA are downstream of ERK/MAPK signaling. Next, we show that intra-LA infusion of the histone deacetylase (HDAC) inhibitor TSA increases H3 acetylation and enhances fear memory consolidation; that is, long-term memory (LTM) is enhanced, while short-term memory (STM) is unaffected. Conversely, intra-LA infusion of the DNA methyltransferase (DNMT) inhibitor 5-AZA impairs fear memory consolidation. Further, intra-LA infusion of 5-AZA was observed to impair training-related increases in H3 acetylation, and pre-treatment with TSA was observed to rescue the memory consolidation deficit induced by 5-AZA. In our final series of experiments, we show that bath application of either 5-AZA or TSA to amygdala slices results in significant impairment or enhancement, respectively, of long-term potentiation (LTP) at both thalamic and cortical inputs to the LA. Further, the deficit in LTP following treatment with 5-AZA was observed to be rescued at both inputs by co-application of TSA. Collectively, these findings provide strong support that histone acetylation and DNA methylation work in concert to regulate memory consolidation of auditory fear conditioning and associated synaptic plasticity in the LA.

  1. The consolidation of implicit sequence memory in obstructive sleep apnea.

    Directory of Open Access Journals (Sweden)

    Eszter Csabi

    Full Text Available Obstructive Sleep Apnea (OSA Syndrome is a relatively frequent sleep disorder characterized by disrupted sleep patterns. It is a well-established fact that sleep has beneficial effect on memory consolidation by enhancing neural plasticity. Implicit sequence learning is a prominent component of skill learning. However, the formation and consolidation of this fundamental learning mechanism remains poorly understood in OSA. In the present study we examined the consolidation of different aspects of implicit sequence learning in patients with OSA. We used the Alternating Serial Reaction Time task to measure general skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 10-hour offline period with sleep. Our data showed differences in offline changes of general skill learning between the OSA and control group. The control group demonstrated offline improvement from evening to morning, while the OSA group did not. In contrast, we did not observe differences between the groups in offline changes in sequence-specific learning. Our findings suggest that disrupted sleep in OSA differently affects neural circuits involved in the consolidation of sequence learning.

  2. Boosting long-term memory via wakeful rest: intentional rehearsal is not necessary, consolidation is sufficient.

    Science.gov (United States)

    Dewar, Michaela; Alber, Jessica; Cowan, Nelson; Della Sala, Sergio

    2014-01-01

    People perform better on tests of delayed free recall if learning is followed immediately by a short wakeful rest than by a short period of sensory stimulation. Animal and human work suggests that wakeful resting provides optimal conditions for the consolidation of recently acquired memories. However, an alternative account cannot be ruled out, namely that wakeful resting provides optimal conditions for intentional rehearsal of recently acquired memories, thus driving superior memory. Here we utilised non-recallable words to examine whether wakeful rest boosts long-term memory, even when new memories could not be rehearsed intentionally during the wakeful rest delay. The probing of non-recallable words requires a recognition paradigm. Therefore, we first established, via Experiment 1, that the rest-induced boost in memory observed via free recall can be replicated in a recognition paradigm, using concrete nouns. In Experiment 2, participants heard 30 non-recallable non-words, presented as 'foreign names in a bridge club abroad' and then either rested wakefully or played a visual spot-the-difference game for 10 minutes. Retention was probed via recognition at two time points, 15 minutes and 7 days after presentation. As in Experiment 1, wakeful rest boosted recognition significantly, and this boost was maintained for at least 7 days. Our results indicate that the enhancement of memory via wakeful rest is not dependent upon intentional rehearsal of learned material during the rest period. We thus conclude that consolidation is sufficient for this rest-induced memory boost to emerge. We propose that wakeful resting allows for superior memory consolidation, resulting in stronger and/or more veridical representations of experienced events which can be detected via tests of free recall and recognition.

  3. Boosting long-term memory via wakeful rest: intentional rehearsal is not necessary, consolidation is sufficient.

    Directory of Open Access Journals (Sweden)

    Michaela Dewar

    Full Text Available People perform better on tests of delayed free recall if learning is followed immediately by a short wakeful rest than by a short period of sensory stimulation. Animal and human work suggests that wakeful resting provides optimal conditions for the consolidation of recently acquired memories. However, an alternative account cannot be ruled out, namely that wakeful resting provides optimal conditions for intentional rehearsal of recently acquired memories, thus driving superior memory. Here we utilised non-recallable words to examine whether wakeful rest boosts long-term memory, even when new memories could not be rehearsed intentionally during the wakeful rest delay. The probing of non-recallable words requires a recognition paradigm. Therefore, we first established, via Experiment 1, that the rest-induced boost in memory observed via free recall can be replicated in a recognition paradigm, using concrete nouns. In Experiment 2, participants heard 30 non-recallable non-words, presented as 'foreign names in a bridge club abroad' and then either rested wakefully or played a visual spot-the-difference game for 10 minutes. Retention was probed via recognition at two time points, 15 minutes and 7 days after presentation. As in Experiment 1, wakeful rest boosted recognition significantly, and this boost was maintained for at least 7 days. Our results indicate that the enhancement of memory via wakeful rest is not dependent upon intentional rehearsal of learned material during the rest period. We thus conclude that consolidation is sufficient for this rest-induced memory boost to emerge. We propose that wakeful resting allows for superior memory consolidation, resulting in stronger and/or more veridical representations of experienced events which can be detected via tests of free recall and recognition.

  4. The effect of mild acute stress during memory consolidation on emotional recognition memory.

    Science.gov (United States)

    Corbett, Brittany; Weinberg, Lisa; Duarte, Audrey

    2017-08-21

    Stress during consolidation improves recognition memory performance. Generally, this memory benefit is greater for emotionally arousing stimuli than neutral stimuli. The strength of the stressor also plays a role in memory performance, with memory performance improving up to a moderate level of stress and thereafter worsening. As our daily stressors are generally minimal in strength, we chose to induce mild acute stress to determine its effect on memory performance. In the current study, we investigated if mild acute stress during consolidation improves memory performance for emotionally arousing images. To investigate this, we had participants encode highly arousing negative, minimally arousing negative, and neutral images. We induced stress using the Montreal Imaging Stress Task (MIST) in half of the participants and a control task to the other half of the participants directly after encoding (i.e. during consolidation) and tested recognition 48 hours later. We found no difference in memory performance between the stress and control group. We found a graded pattern among confidence, with responders in the stress group having the least amount of confidence in their hits and controls having the most. Across groups, we found highly arousing negative images were better remembered than minimally arousing negative or neutral images. Although stress did not affect memory accuracy, responders, as defined by cortisol reactivity, were less confident in their decisions. Our results suggest that the daily stressors humans experience, regardless of their emotional affect, do not have adverse effects on memory. Copyright © 2017. Published by Elsevier Inc.

  5. Acute exercise improves motor memory consolidation in preadolescent children

    DEFF Research Database (Denmark)

    Lundbye-Jensen, Jesper; Skriver, Kasper Christen; Nielsen, Jens Bo

    2017-01-01

    Objective: The ability to acquire new motor skills is essential both during childhood and later in life. Recent studies have demonstrated that an acute bout of exercise can improve motor memory consolidation in adults. The objective of the present study was to investigate whether acute exercise...... protocols following motor skill practice in a school setting can also improve long-term retention of motor memory in preadolescent children. Methods: Seventy-seven pre-adolescent children (age 10.5 ± 0.75 (SD)) participated in the study. Prior to the main experiment age, BMI, fitness status and general...... for exercise groups. Delayed retention of motor memory was assessed 1 h, 24 h and 7 days after motor skill acquisition. Results: During skill acquisition, motor performance improved significantly to the immediate retention test with no differences between groups. One hour following skill acquisition, motor...

  6. Temporal dynamics of immediate early gene expression during cellular consolidation of spatial memory.

    Science.gov (United States)

    Barry, Daniel N; Commins, Sean

    2017-06-01

    The consolidation of newly acquired memories on a cellular level is thought to take place in the first few hours following learning. This process is dependent on de novo protein synthesis during this time, which ultimately leads to long-term structural and functional neuronal changes and the stabilisation of a memory trace. Immediate early genes (IEGs) are rapidly expressed in neurons following learning, and previous research has suggested more than one wave of IEG expression facilitates consolidation in the hours following learning. We analysed the expression of Zif268, c-Fos and Arc protein in a number of brain regions involved in spatial learning either 90min, 4h or 8h following training in the Morris water maze task. Consistent with the role of IEGs in the earliest stages of consolidation, a single wave of expression was observed in most brain regions at 90min, however a subsequent wave of expression was not observed at 8h. In fact, Zif268 expression was observed to fall below the levels of naïve controls at this time-point in the medial prefrontal and perirhinal cortices. This may be indicative of synaptic downscaling in these regions in the hours following learning, and an important marker of the consolidation of spatial memory. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Divided attention improves delayed, but not immediate retrieval of a consolidated memory.

    Directory of Open Access Journals (Sweden)

    Yoav Kessler

    Full Text Available A well-documented dissociation between memory encoding and retrieval concerns the role of attention in the two processes. The typical finding is that divided attention (DA during encoding impairs future memory, but retrieval is relatively robust to attentional manipulations. However, memory research in the past 20 years had demonstrated that retrieval is a memory-changing process, in which the strength and availability of information are modified by various characteristics of the retrieval process. Based on this logic, several studies examined the effects of DA during retrieval (Test 1 on a future memory test (Test 2. These studies yielded inconsistent results. The present study examined the role of memory consolidation in accounting for the after-effect of DA during retrieval. Initial learning required a classification of visual stimuli, and hence involved incidental learning. Test 1 was administered 24 hours after initial learning, and therefore required retrieval of consolidated information. Test 2 was administered either immediately following Test 1 or after a 24-hour delay. Our results show that the effect of DA on Test 2 depended on this delay. DA during Test 1 did not affect performance on Test 2 when it was administered immediately, but improved performance when Test 2 was given 24-hours later. The results are consistent with other findings showing long-term benefits of retrieval difficulty. Implications for theories of reconsolidation in human episodic memory are discussed.

  8. Divided attention improves delayed, but not immediate retrieval of a consolidated memory.

    Science.gov (United States)

    Kessler, Yoav; Vandermorris, Susan; Gopie, Nigel; Daros, Alexander; Winocur, Gordon; Moscovitch, Morris

    2014-01-01

    A well-documented dissociation between memory encoding and retrieval concerns the role of attention in the two processes. The typical finding is that divided attention (DA) during encoding impairs future memory, but retrieval is relatively robust to attentional manipulations. However, memory research in the past 20 years had demonstrated that retrieval is a memory-changing process, in which the strength and availability of information are modified by various characteristics of the retrieval process. Based on this logic, several studies examined the effects of DA during retrieval (Test 1) on a future memory test (Test 2). These studies yielded inconsistent results. The present study examined the role of memory consolidation in accounting for the after-effect of DA during retrieval. Initial learning required a classification of visual stimuli, and hence involved incidental learning. Test 1 was administered 24 hours after initial learning, and therefore required retrieval of consolidated information. Test 2 was administered either immediately following Test 1 or after a 24-hour delay. Our results show that the effect of DA on Test 2 depended on this delay. DA during Test 1 did not affect performance on Test 2 when it was administered immediately, but improved performance when Test 2 was given 24-hours later. The results are consistent with other findings showing long-term benefits of retrieval difficulty. Implications for theories of reconsolidation in human episodic memory are discussed.

  9. Opposite Effects of Cortisol on Consolidation of Temporal Sequence Memory during Waking and Sleep

    Science.gov (United States)

    Wilhelm, Ines; Wagner, Ullrich; Born, Jan

    2011-01-01

    Memory functions involve three stages: encoding, consolidation, and retrieval. Modulating effects of glucocorticoids (GCs) have been consistently observed for declarative memory with GCs enhancing encoding and impairing retrieval, but surprisingly, little is known on how GCs affect memory consolidation. Studies in rats suggest a beneficial effect…

  10. Age-related differences in sleep-based memory consolidation: A meta-analysis.

    Science.gov (United States)

    Gui, Wen-Jun; Li, Hui-Jie; Guo, Yu-Hua; Peng, Peng; Lei, Xu; Yu, Jing

    2017-02-02

    A period of post-learning sleep benefits memory consolidation compared with an equal-length wake interval. However, whether this sleep-based memory consolidation changes as a function of age remains controversial. Here we report a meta-analysis that investigates the age differences in the sleep-based memory consolidation in two types of memory: declarative memory and procedural memory. The meta-analysis included 22 comparisons of the performance between young adults (N =640) and older adults (N =529) on behavioral tasks measuring sleep-based memory consolidation. Our results showed a significant overall sleep-based beneficial effect in young adults but not in older adults. However, further analyses suggested that the age differences were mainly manifested in sleep-based declarative memory consolidation but not in procedural memory consolidation. We discussed the possible underlying mechanisms for the age-related degradation in sleep-based memory consolidation. Further research is needed to determine the crucial components for sleep-related memory consolidation in older adults such as age-related changes in neurobiological and cardiovascular functions, which may play an important role in this context and have the potential to delineate the interrelationships between age-related changes in sleep and memory.

  11. Opposite Effects of Cortisol on Consolidation of Temporal Sequence Memory during Waking and Sleep

    Science.gov (United States)

    Wilhelm, Ines; Wagner, Ullrich; Born, Jan

    2011-01-01

    Memory functions involve three stages: encoding, consolidation, and retrieval. Modulating effects of glucocorticoids (GCs) have been consistently observed for declarative memory with GCs enhancing encoding and impairing retrieval, but surprisingly, little is known on how GCs affect memory consolidation. Studies in rats suggest a beneficial effect…

  12. Dopamine in the dorsal hippocampus impairs the late consolidation of cocaine-associated memory.

    Science.gov (United States)

    Kramar, Cecilia P; Chefer, Vladimir I; Wise, Roy A; Medina, Jorge H; Barbano, M Flavia

    2014-06-01

    Cocaine is thought to be addictive because it elevates dopamine levels in the striatum, reinforcing drug-seeking habits. Cocaine also elevates dopamine levels in the hippocampus, a structure involved in contextual conditioning as well as in reward function. Hippocampal dopamine promotes the late phase of consolidation of an aversive step-down avoidance memory. Here, we examined the role of hippocampal dopamine function in the persistence of the conditioned increase in preference for a cocaine-associated compartment. Blocking dorsal hippocampal D1-type receptors (D1Rs) but not D2-type receptors (D2Rs) 12 h after a single training trial extended persistence of the normally short-lived memory; conversely, a general and a specific phospholipase C-coupled D1R agonist (but not a D2R or adenylyl cyclase-coupled D1R agonist) decreased the persistence of the normally long-lived memory established by three-trial training. These effects of D1 agents were opposite to those previously established in a step-down avoidance task, and were here also found to be opposite to those in a lithium chloride-conditioned avoidance task. After returning to normal following cocaine injection, dopamine levels in the dorsal hippocampus were found elevated again at the time when dopamine antagonists and agonists were effective: between 13 and 17 h after cocaine injection. These findings confirm that, long after the making of a cocaine-place association, hippocampal activity modulates memory consolidation for that association via a dopamine-dependent mechanism. They suggest a dynamic role for dorsal hippocampal dopamine in this late-phase memory consolidation and, unexpectedly, differential roles for late consolidation of memories for places that induce approach or withdrawal because of a drug association.

  13. Consolidation of visuomotor adaptation memory with consistent and noisy environments.

    Science.gov (United States)

    Maeda, Rodrigo S; McGee, Steven E; Marigold, Daniel S

    2017-01-01

    Our understanding of how we learn and retain motor behaviors is still limited. For instance, there is conflicting evidence as to whether the memory of a learned visuomotor perturbation consolidates; i.e., the motor memory becomes resistant to interference from learning a competing perturbation over time. Here, we sought to determine the factors that influence consolidation during visually guided walking. Subjects learned a novel mapping relationship, created by prism lenses, between the perceived location of two targets and the motor commands necessary to direct the feet to their positions. Subjects relearned this mapping 1 wk later. Different groups experienced protocols with or without a competing mapping (and with and without washout trials), presented either on the same day as initial learning or before relearning on day 2 We tested identical protocols under constant and noisy mapping structures. In the latter, we varied, on a trial-by-trial basis, the strength of prism lenses around a non-zero mean. We found that a novel visuomotor mapping is retained at least 1 wk after initial learning. We also found reduced foot-placement error with relearning in constant and noisy mapping groups, despite learning a competing mapping beforehand, and with the exception of one protocol, with and without washout trials. Exposure to noisy mappings led to similar performance on relearning compared with the equivalent constant mapping groups for most protocols. Overall, our results support the idea of motor memory consolidation during visually guided walking and suggest that constant and noisy practices are effective for motor learning.

  14. The central role of heat shock factor 1 in synaptic fidelity and memory consolidation

    National Research Council Canada - National Science Library

    Hooper, Philip L; Durham, Heather D; Török, Zsolt; Hooper, Paul L; Crul, Tim; Vígh, László

    2016-01-01

    ...), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fidelity and function, and in memory consolidation...

  15. The effect of psilocin on memory acquisition, retrieval and consolidation in rat.

    Directory of Open Access Journals (Sweden)

    Lukas eRambousek

    2014-05-01

    Full Text Available The involvement of the serotonin system in the pathophysiology of schizophrenia has been elucidated by experiments with hallucinogens. Application of a hallucinogen to humans leads to changes in perception, cognition, emotions and induction of psychotic-like symptoms that resemble symptoms of schizophrenia. In rodent studies, their acute administration affects sensorimotor gating, locomotor activity, social behavior and cognition including working memory, the phenotypes are considered as an animal model of schizophrenia. The complexity and singularity of human cognition raises questions about the validity of animal models utilizing agonists of 5-HT2A receptors. The present study thus investigated the effect of psilocin on memory acquisition, reinforced retrieval and memory consolidation in rats. Psilocin is a main metabolite of psilocybin acting as an agonist at 5-HT2A receptors with a contribution of 5-HT2C and 5-HT1A receptors. First, we tested the effect of psilocin on the acquisition of a Carousel maze, a spatial task requiring navigation using distal cues, attention and cognitive coordination. Psilocin significantly impaired the acquisition of the Carousel Maze at both doses (1 and 4 mg/kg. The higher dose of psilocin blocked the learning processes even in an additional session when the rats received only saline. Next, we examined the effect of psilocin on reinforced retrieval and consolidation in the Morris water maze (MWM. The dose of 4 mg/kg disrupted reinforced retrieval in the Morris water maze. However, the application of a lower dose was without any significant effect. Finally, neither the low nor high dose of psilocin injected post-training caused a deficit in memory consolidation in the MWM. Taken together, the psilocin dose dependently impaired the acquisition of the Carousel maze and reinforced retrieval in MWM; however, it had no effect on memory consolidation.

  16. Resting-state fMRI evidence for early episodic memory consolidation: effects of age.

    Science.gov (United States)

    Kukolja, Juraj; Göreci, D Yasemin; Onur, Özgür A; Riedl, Valentin; Fink, Gereon R

    2016-09-01

    Aging-related episodic memory decline is often attributed to insufficient encoding of new information, although the underlying neural processes remain elusive. We here tested the hypothesis that impaired memory consolidation contributes to aging-related memory decline. To this end, we used resting state functional magnetic resonance imaging in healthy young and older adults and investigated neural network connectivity underlying episodic memory consolidation and the effects of aging thereon. During postencoding rest, connectivity increased in subregions of temporobasal and temporo-occipital networks but decreased in a precuneal network. These connectivity changes predicted subsequent memory performance thereby constituting functional correlates of early memory consolidation. Furthermore, these consolidation-related regional connectivity changes partially overlapped with encoding-related neural activity changes, suggesting a close relationship between encoding- and consolidation-related activity. Older when compared to young participants failed to increase connectivity in the right lingual gyrus as part of an extended default mode network during consolidation, thereby providing a functional correlate for spatial contextual memory deficits. In conclusion, results are consistent with previous reports of persistent activity in regions mediating memory encoding as a core mechanism underlying episodic memory consolidation. Our data extend previous findings suggesting that aging-related memory decline results from a reduction of consolidation processes.

  17. Locus coeruleus and dopaminergic consolidation of everyday memory

    NARCIS (Netherlands)

    Takeuchi, T.; Duszkiewicz, A.J.; Sonneborn, A.; Spooner, P.A.; Yamasaki, M.; Watanabe, M.; Smith, C.C.; Fernandez, G.S.E.; Deisseroth, K.; Greene, R.W.; Morris, R.G.

    2016-01-01

    The retention of episodic-like memory is enhanced, in humans and animals, when something novel happens shortly before or after encoding. Using an everyday memory task in mice, we sought the neurons mediating this dopamine-dependent novelty effect, previously thought to originate exclusively from the

  18. Acute Exercise Improves Motor Memory Consolidation in Preadolescent Children

    Directory of Open Access Journals (Sweden)

    Jesper Lundbye-Jensen

    2017-04-01

    Full Text Available Objective: The ability to acquire new motor skills is essential both during childhood and later in life. Recent studies have demonstrated that an acute bout of exercise can improve motor memory consolidation in adults. The objective of the present study was to investigate whether acute exercise protocols following motor skill practice in a school setting can also improve long-term retention of motor memory in preadolescent children.Methods: Seventy-seven pre-adolescent children (age 10.5 ± 0.75 (SD participated in the study. Prior to the main experiment age, BMI, fitness status and general physical activity level was assessed in all children and they were then randomly allocated to three groups. All children practiced a visuomotor tracking task followed by 20 min of rest (CON, high intensity intermittent floorball (FLB or running (RUN with comparable exercise intensity and duration for exercise groups. Delayed retention of motor memory was assessed 1 h, 24 h and 7 days after motor skill acquisition.Results: During skill acquisition, motor performance improved significantly to the immediate retention test with no differences between groups. One hour following skill acquisition, motor performance decreased significantly for RUN. Twenty-four hours following skill acquisition there was a tendency towards improved performance for FLB but no significant effects. Seven days after motor practice however, both FLB and RUN performed better when compared to their immediate retention test indicating significant offline gains. This effect was not observed for CON. In contrast, 7 days after motor practice, retention of motor memory was significantly better for FLB and RUN compared to CON. No differences were observed when comparing FLB and RUN.Conclusions: Acute intense intermittent exercise performed immediately after motor skill acquisition facilitates long-term motor memory in pre-adolescent children, presumably by promoting memory consolidation. The

  19. Acute Exercise Improves Motor Memory Consolidation in Preadolescent Children

    Science.gov (United States)

    Lundbye-Jensen, Jesper; Skriver, Kasper; Nielsen, Jens B.; Roig, Marc

    2017-01-01

    Objective: The ability to acquire new motor skills is essential both during childhood and later in life. Recent studies have demonstrated that an acute bout of exercise can improve motor memory consolidation in adults. The objective of the present study was to investigate whether acute exercise protocols following motor skill practice in a school setting can also improve long-term retention of motor memory in preadolescent children. Methods: Seventy-seven pre-adolescent children (age 10.5 ± 0.75 (SD)) participated in the study. Prior to the main experiment age, BMI, fitness status and general physical activity level was assessed in all children and they were then randomly allocated to three groups. All children practiced a visuomotor tracking task followed by 20 min of rest (CON), high intensity intermittent floorball (FLB) or running (RUN) with comparable exercise intensity and duration for exercise groups. Delayed retention of motor memory was assessed 1 h, 24 h and 7 days after motor skill acquisition. Results: During skill acquisition, motor performance improved significantly to the immediate retention test with no differences between groups. One hour following skill acquisition, motor performance decreased significantly for RUN. Twenty-four hours following skill acquisition there was a tendency towards improved performance for FLB but no significant effects. Seven days after motor practice however, both FLB and RUN performed better when compared to their immediate retention test indicating significant offline gains. This effect was not observed for CON. In contrast, 7 days after motor practice, retention of motor memory was significantly better for FLB and RUN compared to CON. No differences were observed when comparing FLB and RUN. Conclusions: Acute intense intermittent exercise performed immediately after motor skill acquisition facilitates long-term motor memory in pre-adolescent children, presumably by promoting memory consolidation. The results also

  20. Endocannabinoids in the rat basolateral amygdala enhance memory consolidation and enable glucocorticoid modulation of memory

    NARCIS (Netherlands)

    Campolongo, Patrizia; Roozendaal, Benno; Trezza, Viviana; Hauer, Daniela; Schelling, Gustav; McGaugh, James L.; Cuomo, Vincenzo

    2009-01-01

    Extensive evidence indicates that the basolateral complex of the amygdala (BLA) modulates the consolidation of memories for emotionally arousing experiences, an effect that involves the activation of the glucocorticoid system. Because the BLA expresses high densities of cannabinoid CB1 receptors, th

  1. Diminished nap effects on memory consolidation are seen under oral contraceptive use

    NARCIS (Netherlands)

    Genzel, L.; Baurle, A.; Potyka, A.; Wehrle, R.; Adamczyk, M.; Friess, E.; Steiger, A.; Dresler, M.

    2014-01-01

    Many young females take exogenous hormones as oral contraceptive (OC), a condition rarely controlled for in studies on sleep and memory consolidation even though sex hormones influence consolidation. This study investigated the effects of OCs on sleep-related consolidation of a motor and declarative

  2. Diminished nap effects on memory consolidation are seen under oral contraceptive use

    NARCIS (Netherlands)

    Genzel, L.; Baurle, A.; Potyka, A.; Wehrle, R.; Adamczyk, M.; Friess, E.; Steiger, A.; Dresler, M.

    2014-01-01

    Many young females take exogenous hormones as oral contraceptive (OC), a condition rarely controlled for in studies on sleep and memory consolidation even though sex hormones influence consolidation. This study investigated the effects of OCs on sleep-related consolidation of a motor and declarative

  3. Arousal and cortisol interact in modulating memory consolidation in healthy young men.

    Science.gov (United States)

    Kuhlmann, Sabrina; Wolf, Oliver T

    2006-02-01

    Animal studies indicate that adrenal glucocorticoids enhance memory consolidation while impairing memory retrieval. In humans, beneficial effects on consolidation have been observed infrequently. In the current double-blind study, subjects (N = 29) received placebo or cortisol (30 mg) 10 min before viewing emotionally arousing or neutral pictures. Cortisol treatment had no effects on immediate recall. In the 24-hr delayed recall condition, cortisol led to an enhanced emotional memory facilitation because of decreased neutral and increased emotional memory recall. No effects of cortisol treatment were observed for recognition memory or mood. Results support the notion that glucocorticoids specifically enhance the consolidation of emotional material.

  4. A role for central nervous growth hormone-releasing hormone signaling in the consolidation of declarative memories.

    Directory of Open Access Journals (Sweden)

    Manfred Hallschmid

    Full Text Available Contributions of somatotropic hormonal activity to memory functions in humans, which are suggested by clinical observations, have not been systematically examined. With previous experiments precluding a direct effect of systemic growth hormone (GH on acute memory formation, we assessed the role of central nervous somatotropic signaling in declarative memory consolidation. We examined the effect of intranasally administered growth hormone releasing-hormone (GHRH; 600 µg that has direct access to the brain and suppresses endogenous GHRH via an ultra-short negative feedback loop. Twelve healthy young men learned word-pair associates at 2030 h and were administered GHRH and placebo, respectively, at 2100 h. Retrieval was tested after 11 hours of wakefulness. Compared to placebo, intranasal GHRH blunted GH release within 3 hours after substance administration and reduced the number of correctly recalled word-pairs by ∼12% (both P<0.05. The impairment of declarative memory consolidation was directly correlated to diminished GH concentrations (P<0.05. Procedural memory consolidation as examined by the parallel assessment of finger sequence tapping performance was not affected by GHRH administration. Our findings indicate that intranasal GHRH, by counteracting endogenous GHRH release, impairs hippocampal memory processing. They provide first evidence for a critical contribution of central nervous somatotropic activity to hippocampus-dependent memory consolidation.

  5. Astrocytic β2-adrenergic receptors mediate hippocampal long-term memory consolidation

    KAUST Repository

    Gao, Virginia

    2016-07-12

    Emotionally relevant experiences form strong and long-lasting memories by critically engaging the stress hormone/neurotransmitter noradrenaline, which mediates and modulates the consolidation of these memories. Noradrenaline acts through adrenergic receptors (ARs), of which β2- Adrenergic receptors (βARs) are of particular importance. The differential anatomical and cellular distribution of βAR subtypes in the brain suggests that they play distinct roles in memory processing, although much about their specific contributions and mechanisms of action remains to be understood. Here we show that astrocytic rather than neuronal β2ARs in the hippocampus play a key role in the consolidation of a fear-based contextual memory. These hippocampal β2ARs, but not β1ARs, are coupled to the training-dependent release of lactate from astrocytes, which is necessary for long- Term memory formation and for underlying molecular changes. This key metabolic role of astrocytic β2ARs may represent a novel target mechanism for stress-related psychopathologies and neurodegeneration.

  6. System Consolidation During Sleep - A Common Principle Underlying Psychological and Immunological Memory Formation

    NARCIS (Netherlands)

    Westermann, Jürgen; Lange, Tanja; Textor, Johannes; Born, Jan

    2015-01-01

    Sleep benefits the consolidation of psychological memory, and there are hints that sleep likewise supports immunological memory formation. Comparing psychological and immunological domains, we make the case for active system consolidation that is similarly established in both domains and partly conv

  7. System consolidation during sleep - a common principle underlying psychological and immunological memory formation

    NARCIS (Netherlands)

    Westermann, J.; Lange, T.; Textor, J.C.; Born, J. van den

    2015-01-01

    Sleep benefits the consolidation of psychological memory, and there are hints that sleep likewise supports immunological memory formation. Comparing psychological and immunological domains, we make the case for active system consolidation that is similarly established in both domains and partly conv

  8. Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults

    NARCIS (Netherlands)

    Berghuis, K. M. M.; Veldman, M. P.; Solnik, S.; Koch, G.; Zijdewind, I.; Hortobagyi, T.

    2015-01-01

    It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation i

  9. Functional and evolutionary trade-offs co-occur between two consolidated memory phases in Drosophila melanogaster.

    Science.gov (United States)

    Lagasse, Fabrice; Moreno, Celine; Preat, Thomas; Mery, Frederic

    2012-10-07

    Memory is a complex and dynamic process that is composed of different phases. Its evolution under natural selection probably depends on a balance between fitness benefits and costs. In Drosophila, two separate forms of consolidated memory phases can be generated experimentally: anaesthesia-resistant memory (ARM) and long-term memory (LTM). In recent years, several studies have focused on the differences between these long-lasting memory types and have found that, at the functional level, ARM and LTM are antagonistic. How this functional relationship will affect their evolutionary dynamics remains unknown. We selected for flies with either improved ARM or improved LTM over several generations, and found that flies selected specifically for improvement of one consolidated memory phase show reduced performance in the other memory phase. We also found that improved LTM was linked to decreased longevity in male flies but not in females. Conversely, males with improved ARM had increased longevity. We found no correlation between either improved ARM or LTM and other phenotypic traits. This is, to our knowledge, the first evidence of a symmetrical evolutionary trade-off between two memory phases for the same learning task. Such trade-offs may have an important impact on the evolution of cognitive capacities. On a neural level, these results support the hypothesis that mechanisms underlying these forms of consolidated memory are, to some degree, antagonistic.

  10. Declarative memory consolidation during the first night in a sleep lab: the role of REM sleep and cortisol.

    Science.gov (United States)

    Goerke, Monique; Cohrs, Stefan; Rodenbeck, Andrea; Grittner, Ulrike; Sommer, Werner; Kunz, Dieter

    2013-07-01

    While the consolidation of declarative memory is supported by slow wave sleep (SWS) in healthy subjects, it has been shown to be associated with rapid eye movement (REM) sleep in patients with insomnia. Sleep during a subject's first night in an unfamiliar environment is often disturbed, and this so-called first-night effect (FNE) has often been used as a model of transient insomnia. Additionally, sleeping for the first time in an unfamiliar environment can lead to increased cortisol secretion, and declarative memory consolidation likely depends on low cortisol levels, especially during the early part of the night. Accounting for intersubject variability in the FNE, we examined the relationship between sleep stages, cortisol secretion and declarative memory performance in 27 healthy young men. Declarative memory performance improved significantly after sleep. Whereas memory performance during the learning session and retrieval testing was strongly associated with cortisol secretion, the overnight gain was not. Post hoc analyses indicated that the overnight gain appears to be modulated by the extent of the FNE: a significant overnight improvement in memory performance was found only in subjects with a weak FNE (n=12). In these subjects, no association was found between any sleep stage and the improvement observed in their memory performance. In subjects with a strong FNE (n=12), however, the overnight change in memory performance was associated with the proportion of REM sleep and the total number of REMs. Disturbed sleep in an unfamiliar environment therefore appears to affect the memory consolidation process.

  11. PV plasticity sustained through D1/5 dopamine signaling required for long-term memory consolidation.

    Science.gov (United States)

    Karunakaran, Smitha; Chowdhury, Ananya; Donato, Flavio; Quairiaux, Charles; Michel, Christoph M; Caroni, Pico

    2016-03-01

    Long-term consolidation of memories depends on processes occurring many hours after acquisition. Whether this involves plasticity that is specifically required for long-term consolidation remains unclear. We found that learning-induced plasticity of local parvalbumin (PV) basket cells was specifically required for long-term, but not short/intermediate-term, memory consolidation in mice. PV plasticity, which involves changes in PV and GAD67 expression and connectivity onto PV neurons, was regulated by cAMP signaling in PV neurons. Following induction, PV plasticity depended on local D1/5 dopamine receptor signaling at 0-5 h to regulate its magnitude, and at 12-14 h for its continuance, ensuring memory consolidation. D1/5 dopamine receptor activation selectively induced DARPP-32 and ERK phosphorylation in PV neurons. At 12-14 h, PV plasticity was required for enhanced sharp-wave ripple densities and c-Fos expression in pyramidal neurons. Our results reveal general network mechanisms of long-term memory consolidation that requires plasticity of PV basket cells induced after acquisition and sustained subsequently through D1/5 receptor signaling.

  12. Functional Integrity of the Retrosplenial Cortex Is Essential for Rapid Consolidation and Recall of Fear Memory

    Science.gov (United States)

    Katche, Cynthia; Dorman, Guido; Slipczuk, Leandro; Cammarota, Martin; Medina, Jorge H.

    2013-01-01

    Memory storage is a temporally graded process involving different phases and different structures in the mammalian brain. Cortical plasticity is essential to store stable memories, but little is known regarding its involvement in memory processing. Here we show that fear memory consolidation requires early post-training macromolecular synthesis in…

  13. Functional Integrity of the Retrosplenial Cortex Is Essential for Rapid Consolidation and Recall of Fear Memory

    Science.gov (United States)

    Katche, Cynthia; Dorman, Guido; Slipczuk, Leandro; Cammarota, Martin; Medina, Jorge H.

    2013-01-01

    Memory storage is a temporally graded process involving different phases and different structures in the mammalian brain. Cortical plasticity is essential to store stable memories, but little is known regarding its involvement in memory processing. Here we show that fear memory consolidation requires early post-training macromolecular synthesis in…

  14. The MAP(K) of fear: from memory consolidation to memory extinction.

    Science.gov (United States)

    Cestari, Vincenzo; Rossi-Arnaud, Clelia; Saraulli, Daniele; Costanzi, Marco

    2014-06-01

    The highly conserved mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling cascade is involved in several intracellular processes ranging from cell differentiation to proliferation, as well as in synaptic plasticity. In the last two decades, the role of MAPK/ERK in long-term memory formation in mammals, particularly in fear-related memories, has been extensively investigated. In this review we describe knowledge advancement on the role of MAPK/ERK in orchestrating the intracellular processes that lead to the consolidation, reconsolidation and extinction of fear memories. In doing so, we report studies in which the specific role of MAP/ERK in switching from memory formation to memory erasure has been suggested. The possibility to target MAPK/ERK in developing and/or refining pharmacological approaches to treat psychiatric disorders in which fear regulation is defective has also been envisaged. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Involvement of the insular cortex in regulating glucocorticoid effects on memory consolidation of inhibitory avoidance training

    Directory of Open Access Journals (Sweden)

    Raquel eFornari

    2012-03-01

    Full Text Available Glucocorticoids are known to enhance the consolidation of memory of emotionally arousing experiences by acting upon a network of interconnected brain regions. Although animal studies typically do not consider the insular cortex (IC to be part of this network, the present findings indicate that the IC is importantly involved in regulating glucocorticoid effects on memory consolidation of emotionally arousing inhibitory avoidance training. The specific glucocorticoid receptor agonist RU 28362 (3 or 10 ng in 0.5 l infused bilaterally into the IC of male Sprague-Dawley rats immediately after one-trial inhibitory avoidance training dose-dependently enhanced 48-h retention performance. Moreover, training on the inhibitory avoidance task increased neuronal activity of the IC, as assessed by an increased number of cells expressing immunoreactivity for phosphorylated extracellular signal-regulated kinase 1/2 (pERK1/2. However, systemic administration of a memory-enhancing dose of corticosterone (1 mg/kg after inhibitory avoidance training rapidly reduced the number of pERK1/2-positive cells in the IC, suggesting that glucocorticoid administration reduces overall neuronal activity of the IC. To investigate which components of the inhibitory avoidance training experience were influenced by the intra-IC glucocorticoid administration, in the last experiment rats were trained on a modified inhibitory avoidance task in which context exposure and footshock training occur on two sequential days. RU 28362 administration into the IC enhanced later retention when infused immediately after either the context or footshock training. Thus, these findings indicate that the IC mediates glucocorticoid effects on the consolidation of memory of different components of inhibitory avoidance training and suggest that the IC might be an important element of the rodent brain network involved in emotional regulation of learning and memory.

  16. Transforming Growth Factor ß Recruits Persistent MAPK Signaling to Regulate Long-Term Memory Consolidation in "Aplysia Californica"

    Science.gov (United States)

    Shobe, Justin; Philips, Gary T.; Carew, Thomas J.

    2016-01-01

    In this study, we explore the mechanistic relationship between growth factor signaling and kinase activity that supports the protein synthesis-dependent phase of long-term memory (LTM) consolidation for sensitization of "Aplysia." Specifically, we examine LTM for tail shock-induced sensitization of the tail-elicited siphon withdrawal…

  17. Stress Enables Reinforcement-Elicited Serotonergic Consolidation of Fear Memory.

    Science.gov (United States)

    Baratta, Michael V; Kodandaramaiah, Suhasa B; Monahan, Patrick E; Yao, Junmei; Weber, Michael D; Lin, Pei-Ann; Gisabella, Barbara; Petrossian, Natalie; Amat, Jose; Kim, Kyungman; Yang, Aimei; Forest, Craig R; Boyden, Edward S; Goosens, Ki A

    2016-05-15

    Prior exposure to stress is a risk factor for developing posttraumatic stress disorder (PTSD) in response to trauma, yet the mechanisms by which this occurs are unclear. Using a rodent model of stress-based susceptibility to PTSD, we investigated the role of serotonin in this phenomenon. Adult mice were exposed to repeated immobilization stress or handling, and the role of serotonin in subsequent fear learning was assessed using pharmacologic manipulation and western blot detection of serotonin receptors, measurements of serotonin, high-speed optogenetic silencing, and behavior. Both dorsal raphe serotonergic activity during aversive reinforcement and amygdala serotonin 2C receptor (5-HT2CR) activity during memory consolidation were necessary for stress enhancement of fear memory, but neither process affected fear memory in unstressed mice. Additionally, prior stress increased amygdala sensitivity to serotonin by promoting surface expression of 5-HT2CR without affecting tissue levels of serotonin in the amygdala. We also showed that the serotonin that drives stress enhancement of associative cued fear memory can arise from paired or unpaired footshock, an effect not predicted by theoretical models of associative learning. Stress bolsters the consequences of aversive reinforcement, not by simply enhancing the neurobiological signals used to encode fear in unstressed animals, but rather by engaging distinct mechanistic pathways. These results reveal that predictions from classical associative learning models do not always hold for stressed animals and suggest that 5-HT2CR blockade may represent a promising therapeutic target for psychiatric disorders characterized by excessive fear responses such as that observed in PTSD. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  18. Time- but not sleep-dependent consolidation promotes the emergence of cross-modal conceptual representations.

    Science.gov (United States)

    Hennies, Nora; Lewis, Penelope A; Durrant, Simon J; Cousins, James N; Ralph, Matthew A Lambon

    2014-10-01

    Conceptual knowledge about objects comprises a diverse set of multi-modal and generalisable information, which allows us to bring meaning to the stimuli in our environment. The formation of conceptual representations requires two key computational challenges: integrating information from different sensory modalities and abstracting statistical regularities across exemplars. Although these processes are thought to be facilitated by offline memory consolidation, investigations into how cross-modal concepts evolve offline, over time, rather than with continuous category exposure are still missing. Here, we aimed to mimic the formation of new conceptual representations by reducing this process to its two key computational challenges and exploring its evolution over an offline retention period. Participants learned to distinguish between members of two abstract categories based on a simple one-dimensional visual rule. Underlying the task was a more complex hidden indicator of category structure, which required the integration of information across two sensory modalities. In two experiments we investigated the impact of time- and sleep-dependent consolidation on category learning. Our results show that offline memory consolidation facilitated cross-modal category learning. Surprisingly, consolidation across wake, but not across sleep showed this beneficial effect. By demonstrating the importance of offline consolidation the current study provided further insights into the processes that underlie the formation of conceptual representations. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Increases in cAMP, MAPK Activity and CREB Phosphorylation during REM Sleep: Implications for REM Sleep and Memory Consolidation

    OpenAIRE

    Luo, Jie; Phan, Trongha X.; Yang, Yimei; Garelick, Michael G.; Storm, Daniel R.

    2013-01-01

    The cyclic adenosine monophosphate (cAMP), mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB) transcriptional pathway is required for consolidation of hippocampus-dependent memory. In mice, this pathway undergoes a circadian oscillation required for memory persistence that reaches a peak during the daytime. Since mice exhibit polyphasic sleep patterns during the day, this suggested the interesting possibility that cAMP, MAPK activity and CREB phosphorylat...

  20. Dorsal medial prefrontal cortex contributes to conditioned taste aversion memory consolidation and retrieval.

    Science.gov (United States)

    Gonzalez, Maria Carolina; Villar, Maria Eugenia; Igaz, Lionel M; Viola, Haydée; Medina, Jorge H

    2015-12-01

    The medial prefrontal cortex (mPFC) is known for its role in decision making and memory processing, including the participation in the formation of extinction memories. However, little is known regarding its contribution to aversive memory consolidation. Here we demonstrate that neural activity and protein synthesis are required in the dorsal mPFC for memory formation of a conditioned taste aversion (CTA) task and that this region is involved in the retrieval of recent and remote long-term CTA memory. In addition, both NMDA receptor and CaMKII activity in dorsal mPFC are needed for CTA memory consolidation, highlighting the complexity of mPFC functions.

  1. Inhibition of glycogenolysis in astrocytes interrupts memory consolidation in young chickens.

    Science.gov (United States)

    Gibbs, Marie E; Anderson, Damian G; Hertz, Leif

    2006-08-15

    Glycolysis and glycogenolysis are involved in memory processing in day-old chickens and, aside from the provision of energy for neuronal and astrocytic energy metabolism these pathways enable astrocytes to supply neurones with precursor for transmitter glutamate by glucose-based de novo synthesis. We have previously shown that memory processing for bead discrimination learning is dependent on glycolysis; however, the metabolic inhibitor used, iodoacetate, inhibits pyruvate formation from both glucose and glycogen. At specific time points after training transient reductions in brain glycogen content occur, mirrored by increases in glutamate/glutamine content. In the present study, we used intracerebral injection of a glycogen phosphorylase inhibitor, 1,4-dideoxy-1,4-imino-D-arabinitol (DAB), which does not affect glucose breakdown, to evaluate the role of glycogen metabolism in memory consolidation. Dose-dependent inhibition of learning occurred when DAB was administered at specific time periods in relation to training: (i) 5 min before training, (ii) around 30 min posttraining, and (iii) 55 min posttraining. After injection at either of the two earlier periods, memory disappeared after consolidation 30 min postlearning, and after injection 55 min after learning memory was absent at 70 min. The memory loss caused by early administration could be prevented after training by central injection of the glutamate precursor glutamine or the astrocyte-specific substrate acetate together with aspartate, substituting for pyruvate carboxylation. Thus, glycogenolysis is essential for learning in this paradigm and, aside from energy supply considerations, we suggest that an important role for glycogenolysis is to provide neurones with glutamine as the precursor for neuronal glutamate and GABA.

  2. [Current understanding of sleep, dreaming and related memory consolidation].

    Science.gov (United States)

    Han, Victor Z; Shi, Jun-Han

    2013-12-01

    Sleep is a naturally recurring state found throughout the animal kingdom and characterized by a reversible loss of consciousness. Although in humans the daily amount of sleep decreases with aging, the total amount of time spent for sleep is estimated as up to one-third of one's lifetime. In mammals, sleep shows a clear daily rhythmicity as well as nightly phases, which are strongly controlled by the circadian clock located in the hypothalamic suprachiasmatic nuclei and are also regulated by ambient light. While it is certain that sleep is critical for survival in general, the functional significance of sleep is still under investigation. Dreaming is a common psychological phenomenon occurring during human sleep, yet its content and natural function, if any, are still a matter of debate. In recent years, accumulated evidence strongly supports the notion that new information acquired during the day time is processed and transformed into long-term memory in a complicated and sophisticated way during sleeping. Such information processing is commonly referred to as memory consolidation.

  3. Chronic corticosterone exposure persistently elevates the expression of memory-related genes in the lateral amygdala and enhances the consolidation of a Pavlovian fear memory.

    Science.gov (United States)

    Monsey, Melissa S; Boyle, Lara M; Zhang, Melinda L; Nguyen, Caroline P; Kronman, Hope G; Ota, Kristie T; Duman, Ronald S; Taylor, Jane R; Schafe, Glenn E

    2014-01-01

    Chronic exposure to stress has been widely implicated in the development of anxiety disorders, yet relatively little is known about the long-term effects of chronic stress on amygdala-dependent memory formation. Here, we examined the effects of a history of chronic exposure to the stress-associated adrenal steroid corticosterone (CORT) on the consolidation of a fear memory and the expression of memory-related immediate early genes (IEGs) in the lateral nucleus of the amygdala (LA). Rats received chronic exposure to CORT (50 μg/ml) in their drinking water for 2 weeks and were then titrated off the CORT for an additional 6 days followed by a 2 week 'wash-out' period consisting of access to plain water. Rats were then either sacrificed to examine the expression of memory-related IEG expression in the LA or given auditory Pavlovian fear conditioning. We show that chronic exposure to CORT leads to a persistent elevation in the expression of the IEGs Arc/Arg3.1 and Egr-1 in the LA. Further, we show that rats with a history of chronic CORT exposure exhibit enhanced consolidation of a fear memory; short-term memory (STM) is not affected, while long-term memory (LTM) is significantly enhanced. Treatment with the selective serotonin reuptake inhibitor (SSRI) fluoxetine following the chronic CORT exposure period was observed to effectively reverse both the persistent CORT-related increases in memory-related IEG expression in the LA and the CORT-related enhancement in fear memory consolidation. Our findings suggest that chronic exposure to CORT can regulate memory-related IEG expression and fear memory consolidation processes in the LA in a long-lasting manner and that treatment with fluoxetine can reverse these effects.

  4. Chronic corticosterone exposure persistently elevates the expression of memory-related genes in the lateral amygdala and enhances the consolidation of a Pavlovian fear memory.

    Directory of Open Access Journals (Sweden)

    Melissa S Monsey

    Full Text Available Chronic exposure to stress has been widely implicated in the development of anxiety disorders, yet relatively little is known about the long-term effects of chronic stress on amygdala-dependent memory formation. Here, we examined the effects of a history of chronic exposure to the stress-associated adrenal steroid corticosterone (CORT on the consolidation of a fear memory and the expression of memory-related immediate early genes (IEGs in the lateral nucleus of the amygdala (LA. Rats received chronic exposure to CORT (50 μg/ml in their drinking water for 2 weeks and were then titrated off the CORT for an additional 6 days followed by a 2 week 'wash-out' period consisting of access to plain water. Rats were then either sacrificed to examine the expression of memory-related IEG expression in the LA or given auditory Pavlovian fear conditioning. We show that chronic exposure to CORT leads to a persistent elevation in the expression of the IEGs Arc/Arg3.1 and Egr-1 in the LA. Further, we show that rats with a history of chronic CORT exposure exhibit enhanced consolidation of a fear memory; short-term memory (STM is not affected, while long-term memory (LTM is significantly enhanced. Treatment with the selective serotonin reuptake inhibitor (SSRI fluoxetine following the chronic CORT exposure period was observed to effectively reverse both the persistent CORT-related increases in memory-related IEG expression in the LA and the CORT-related enhancement in fear memory consolidation. Our findings suggest that chronic exposure to CORT can regulate memory-related IEG expression and fear memory consolidation processes in the LA in a long-lasting manner and that treatment with fluoxetine can reverse these effects.

  5. Interaction between episodic and semantic memory networks in the acquisition and consolidation of novel spoken words.

    Science.gov (United States)

    Takashima, Atsuko; Bakker, Iske; van Hell, Janet G; Janzen, Gabriele; McQueen, James M

    2017-04-01

    When a novel word is learned, its memory representation is thought to undergo a process of consolidation and integration. In this study, we tested whether the neural representations of novel words change as a function of consolidation by observing brain activation patterns just after learning and again after a delay of one week. Words learned with meanings were remembered better than those learned without meanings. Both episodic (hippocampus-dependent) and semantic (dependent on distributed neocortical areas) memory systems were utilised during recognition of the novel words. The extent to which the two systems were involved changed as a function of time and the amount of associated information, with more involvement of both systems for the meaningful words than for the form-only words after the one-week delay. These results suggest that the reason the meaningful words were remembered better is that their retrieval can benefit more from these two complementary memory systems. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Coupling of Thalamocortical Sleep Oscillations Are Important for Memory Consolidation in Humans.

    Directory of Open Access Journals (Sweden)

    Mohammad Niknazar

    Full Text Available Sleep, specifically non-rapid eye movement (NREM sleep, is thought to play a critical role in the consolidation of recent memories. Two main oscillatory activities observed during NREM, cortical slow oscillations (SO, 0.5-1.0 Hz and thalamic spindles (12-15 Hz, have been shown to independently correlate with memory improvement. Yet, it is not known how these thalamocortical events interact, or the significance of this interaction, during the consolidation process. Here, we found that systemic administration of the GABAergic drug (zolpidem increased both the phase-amplitude coupling between SO and spindles, and verbal memory improvement in humans. These results suggest that thalamic spindles that occur during transitions to the cortical SO Up state are optimal for memory consolidation. Our study predicts that the timely interactions between cortical and thalamic events during consolidation, contribute to memory improvement and is mediated by the level of inhibitory neurotransmission.

  7. Sleep-related memory consolidation in depression: an emerging field of research.

    Science.gov (United States)

    Hornung, Orla Patricia; Regen, Francesca; Danker-Hopfe, Heidi; Heuser, Isabella; Anghelescu, Ion

    2008-01-01

    Sleep-related memory consolidation has received increasing attention in recent years. Because previous research has focused on healthy young adults, only very few studies have been conducted in patients with psychiatric disorders so far. The investigation of sleep-related memory consolidation in depression offers a wide range of future research opportunities and can therefore be regarded as an emerging field of research. This article gives a short overview of current knowledge of sleep-related memory consolidation in healthy young adults and builds a bridge to psychiatry and depression, where further research is urgently needed.

  8. Mind racing: The influence of exercise on long-term memory consolidation.

    Science.gov (United States)

    McNerney, M Windy; Radvansky, Gabriel A

    2015-01-01

    Over time, regular exercise can lower the risk for age-related decline in cognition. However, the immediate effects of exercise on memory consolidation in younger adults have not been fully investigated. In two experiments, the effects of exercise were assessed on three different memory tasks. These included paired-associate learning, procedural learning and text memory. Results indicate that performance on procedural learning and situation model memory was increased with exercise, regardless of if participants exercised before or after encoding. No benefit of exercise was found for paired-associate learning. These findings suggest that intense exercise may benefit certain types of memory consolidation.

  9. The cortical structure of consolidated memory: a hypothesis on the role of the cingulate-entorhinal cortical connection.

    Science.gov (United States)

    Insel, Nathan; Takehara-Nishiuchi, Kaori

    2013-11-01

    Daily experiences are represented by networks of neurons distributed across the neocortex, bound together for rapid storage and later retrieval by the hippocampus. While the hippocampus is necessary for retrieving recent episode-based memory associations, over time, consolidation processes take place that enable many of these associations to be expressed independent of the hippocampus. It is generally thought that mechanisms of consolidation involve synaptic weight changes between cortical regions; or, in other words, the formation of "horizontal" cortico-cortical connections. Here, we review anatomical, behavioral, and physiological data which suggest that the connections in and between the entorhinal and cingulate cortices may be uniquely important for the long-term storage of memories that initially depend on the hippocampus. We propose that current theories of consolidation that divide memory into dual systems of hippocampus and neocortex might be improved by introducing a third, middle layer of entorhinal and cingulate allocortex, the synaptic weights within which are necessary and potentially sufficient for maintaining initially hippocampus-dependent associations over long time periods. This hypothesis makes a number of still untested predictions, and future experiments designed to address these will help to fill gaps in the current understanding of the cortical structure of consolidated memory.

  10. Locus coeruleus and dopaminergic consolidation of everyday memory

    Science.gov (United States)

    Takeuchi, Tomonori; Duszkiewicz, Adrian J.; Sonneborn, Alex; Spooner, Patrick A.; Yamasaki, Miwako; Watanabe, Masahiko; Smith, Caroline C.; Fernández, Guillén; Deisseroth, Karl; Greene, Robert W.; Morris, Richard G. M.

    2016-01-01

    Summary The retention of episodic-like memory is enhanced, in humans and animals, when something novel happens shortly before or after encoding. Using an everyday memory task in mice, we sought the neurons mediating this dopamine-dependent novelty effect, previously thought to originate exclusively from the tyrosine hydroxylase-expressing (TH+) neurons in the ventral tegmental area (VTA). We report that neuronal firing in the locus coeruleus (LC) is especially sensitive to environmental novelty, LC-TH+ neurons project more profusely than VTA-TH+ neurons to the hippocampus, optogenetic activation of LC-TH+ neurons mimics the novelty effect, and this novelty-associated memory enhancement is unaffected by VTA inactivation. Surprisingly, two effects of LC-TH+ photoactivation are sensitive to hippocampal D1/D5 receptor blockade and resistant to adrenoceptors blockade – memory enhancement and long lasting potentiation of synaptic transmission in CA1 ex vivo. Thus, LC-TH+ neurons can mediate post-encoding memory enhancement in a manner consistent with possible co-release of dopamine in hippocampus. PMID:27602521

  11. Effects of the swimming exercise on the consolidation and persistence of auditory and contextual fear memory.

    Science.gov (United States)

    Faria, Rodolfo Souza; Gutierres, Luís Felipe Soares; Sobrinho, Fernando César Faria; Miranda, Iris do Vale; Reis, Júlia Dos; Dias, Elayne Vieira; Sartori, Cesar Renato; Moreira, Dalmo Antonio Ribeiro

    2016-08-15

    Exposure to negative environmental events triggers defensive behavior and leads to the formation of aversive associative memory. Cellular and molecular changes in the central nervous system underlie this memory formation, as well as the associated behavioral changes. In general, memory process is established in distinct phases such as acquisition, consolidation, evocation, persistence, and extinction of the acquired information. After exposure to a particular event, early changes in involved neural circuits support the memory consolidation, which corresponds to the short-term memory. Re-exposure to previously memorized events evokes the original memory, a process that is considered essential for the reactivation and consequent persistence of memory, ensuring that long-term memory is established. Different environmental stimuli may modulate the memory formation process, as well as their distinct phases. Among the different environmental stimuli able of modulating memory formation is the physical exercise which is a potent modulator of neuronal activity. There are many studies showing that physical exercise modulates learning and memory processes, mainly in the consolidation phase of the explicit memory. However, there are few reports in the literature regarding the role of physical exercise in implicit aversive associative memory, especially at the persistence phase. Thus, the present study aimed to investigate the relationship between swimming exercise and the consolidation and persistence of contextual and auditory-cued fear memory. Male Wistar rats were submitted to sessions of swimming exercise five times a week, over six weeks. After that, the rats were submitted to classical aversive conditioning training by a pairing tone/foot shock paradigm. Finally, rats were evaluated for consolidation and persistence of fear memory to both auditory and contextual cues. Our results demonstrate that classical aversive conditioning with tone/foot shock pairing induced

  12. Effects of daytime food intake on memory consolidation during sleep or sleep deprivation.

    Directory of Open Access Journals (Sweden)

    Nina Herzog

    Full Text Available Sleep enhances memory consolidation. Bearing in mind that food intake produces many metabolic signals that can influence memory processing in humans (e.g., insulin, the present study addressed the question as to whether the enhancing effect of sleep on memory consolidation is affected by the amount of energy consumed during the preceding daytime. Compared to sleep, nocturnal wakefulness has been shown to impair memory consolidation in humans. Thus, a second question was to examine whether the impaired memory consolidation associated with sleep deprivation (SD could be compensated by increased daytime energy consumption. To these aims, 14 healthy normal-weight men learned a finger tapping sequence (procedural memory and a list of semantically associated word pairs (declarative memory. After the learning period, standardized meals were administered, equaling either ∼50% or ∼150% of the estimated daily energy expenditure. In the morning, after sleep or wakefulness, memory consolidation was tested. Plasma glucose was measured both before learning and retrieval. Polysomnographic sleep recordings were performed by electroencephalography (EEG. Independent of energy intake, subjects recalled significantly more word pairs after sleep than they did after SD. When subjects stayed awake and received an energy oversupply, the number of correctly recalled finger sequences was equal to those seen after sleep. Plasma glucose did not differ among conditions, and sleep time in the sleep conditions was not influenced by the energy intake interventions. These data indicate that the daytime energy intake level affects neither sleep's capacity to boost the consolidation of declarative and procedural memories, nor sleep's quality. However, high energy intake was followed by an improved procedural but not declarative memory consolidation under conditions of SD. This suggests that the formation of procedural memory is not only triggered by sleep but is also

  13. Episodic Memory in Alzheimer Disease, Frontotemporal Dementia, and Dementia With Lewy Bodies/Parkinson Disease Dementia: Disentangling Retrieval From Consolidation.

    Science.gov (United States)

    Economou, Alexandra; Routsis, Christopher; Papageorgiou, Sokratis G

    2016-01-01

    Differences in episodic memory performance in patients with Alzheimer disease (AD), frontotemporal dementia (FTD), dementia with Lewy bodies (DLB)/Parkinson disease with dementia (PDD) are inconsistent and task dependent. The inconsistencies may be attributed to the different tasks drawing on different memory processes. Few studies have examined episodic memory impairment in the above groups using memory tests that facilitate encoding, to distinguish memory deficits due to impairment of specific processes. We examined the memory performance of 106 AD patients, 51 FTD patients, 26 DLB/PDD patients, and 37 controls using the Five-Words Test, a 5-item memory test that facilitates encoding. The patient groups did not differ in modified Mini Mental State Examination scores. AD patients scored lowest on the Five-Words Test overall, and showed the greatest reduction from immediate total recall to delayed free recall relative to the other 2 groups, consistent with a predominantly consolidation deficit. DLB/PDD patients showed the largest improvement from delayed free to delayed total recall relative to the other 2 groups, consistent with a predominantly retrieval deficit. Deficits in both consolidation and retrieval underlie the memory impairment of the patients, to different extents, and contribute to the theoretical understanding of the nature of the memory impairment of the patient groups.

  14. Light sleep versus slow wave sleep in memory consolidation: a question of global versus local processes?

    NARCIS (Netherlands)

    Genzel, L.; Kroes, M.C.W.; Dresler, M.; Battaglia, F.P.

    2014-01-01

    Sleep is strongly involved in memory consolidation, but its role remains unclear. 'Sleep replay', the active potentiation of relevant synaptic connections via reactivation of patterns of network activity that occurred during previous experience, has received considerable attention. Alternatively, sl

  15. Acute exercise and motor memory consolidation: The role of exercise timing

    DEFF Research Database (Denmark)

    Thomas, Richard; Beck, Mikkel Malling; Lind, Rune Rasmussen;

    2016-01-01

    greater for EX90 than CON (p higher than CON (p ... diminish as the temporal proximity of exercise from acquisition is increased. Timing of exercise following motor practice is important for motor memory consolidation....

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

    Science.gov (United States)

    Murayama, Kou; Kitagami, Shinji

    2014-02-01

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

  17. Acute exercise and motor memory consolidation: Does exercise type play a role?

    DEFF Research Database (Denmark)

    Thomas, Richard; Flindtgaard, Mads; Skriver, Kasper Christen

    2017-01-01

    d. The results demonstrate that high-intensity, acute exercise can lead to a decrease in motor performance assessed shortly after motor skill practice (R1h), but enhances offline effects promoting long-term retention (R1d). Given that different exercise modalities produced similar positive off...... following visuomotor skill acquisition on the retention of motor memory in 40 young (25.3 ±3.6 years), able-bodied male participants randomly assigned to one of four groups either performing strength training (STR), circuit training (CT), indoor hockey (HOC) or rest (CON). Retention tests of the motor skill......-line effects on motor memory, we conclude that exercise-induced effects beneficial to consolidation appear to depend primarily on the physiological stimulus rather than type of exercise and movements employed....

  18. The Roles of Protein Expression in Synaptic Plasticity and Memory Consolidation

    Directory of Open Access Journals (Sweden)

    Tali eRosenberg

    2014-11-01

    Full Text Available The amount and availability of proteins are regulated by their synthesis, degradation, and transport. These processes can specifically, locally, and temporally regulate a protein or a population of proteins, thus affecting numerous biological processes in health and disease states. Accordingly, malfunction in the processes of protein turnover and localization underlies different neuronal diseases. However, as early as a century ago, it was recognized that there is a specific need for normal macromolecular synthesis in a specific fragment of the learning process, memory consolidation, which takes place minutes to hours following acquisition. Memory consolidation is the process by which fragile short-term memory is converted into stable long-term memory. It is accepted today that synaptic plasticity is a cellular mechanism of learning and memory processes. Interestingly, similar molecular mechanisms subserve both memory and synaptic plasticity consolidation. In this review, we survey the current view on the connection between memory consolidation processes and proteostasis, i.e., maintaining the protein contents at the neuron and the synapse. In addition, we describe the technical obstacles and possible new methods to determine neuronal proteostasis of synaptic function and better explain the process of memory and synaptic plasticity consolidation.

  19. Differential Needs of Zinc in the CA3 Area of Dorsal Hippocampus for the Consolidation of Contextual Fear and Spatial Memories

    Science.gov (United States)

    Ceccom, Johnatan; Bouhsira, Emilie; Halley, Helene; Daumas, Stephanie; Lassalle, Jean Michel

    2013-01-01

    One peculiarity of the hippocampal CA3 mossy fiber terminals is the co-release of zinc and glutamate upon synaptic transmission. How these two players act on hippocampal-dependent memories is still unclear. To decipher their respective involvement in memory consolidation, a pharmacological approach was chosen. Using two hippocampal-dependent…

  20. The effect of exogenous cortisol during sleep on the behavioral and neural correlates of emotional memory consolidation in humans

    NARCIS (Netherlands)

    Marle, H.J.F. van; Hermans, E.J.; Qin, S.; Overeem, S.; Fernandez, G.S.E.

    2013-01-01

    A host of animal work demonstrates that the retention benefit for emotionally aversive over neutral memories is regulated by glucocorticoid action during memory consolidation. Particularly, glucocorticoids may affect systems-level processes that promote the gradual reorganization of emotional memory

  1. Increases in cAMP, MAPK activity, and CREB phosphorylation during REM sleep: implications for REM sleep and memory consolidation.

    Science.gov (United States)

    Luo, Jie; Phan, Trongha X; Yang, Yimei; Garelick, Michael G; Storm, Daniel R

    2013-04-10

    The cyclic adenosine monophosphate (cAMP), mitogen-activated protein kinase (MAPK), and cAMP response element-binding protein (CREB) transcriptional pathway is required for consolidation of hippocampus-dependent memory. In mice, this pathway undergoes a circadian oscillation required for memory persistence that reaches a peak during the daytime. Because mice exhibit polyphasic sleep patterns during the day, this suggested the interesting possibility that cAMP, MAPK activity, and CREB phosphorylation may be elevated during sleep. Here, we report that cAMP, phospho-p44/42 MAPK, and phospho-CREB are higher in rapid eye movement (REM) sleep compared with awake mice but are not elevated in non-REM sleep. This peak of activity during REM sleep does not occur in mice lacking calmodulin-stimulated adenylyl cyclases, a mouse strain that learns but cannot consolidate hippocampus-dependent memory. We conclude that a preferential increase in cAMP, MAPK activity, and CREB phosphorylation during REM sleep may contribute to hippocampus-dependent memory consolidation.

  2. Selective REM-sleep deprivation does not diminish emotional memory consolidation in young healthy subjects.

    Directory of Open Access Journals (Sweden)

    Jarste Morgenthaler

    Full Text Available Sleep enhances memory consolidation and it has been hypothesized that rapid eye movement (REM sleep in particular facilitates the consolidation of emotional memory. The aim of this study was to investigate this hypothesis using selective REM-sleep deprivation. We used a recognition memory task in which participants were shown negative and neutral pictures. Participants (N=29 healthy medical students were separated into two groups (undisturbed sleep and selective REM-sleep deprived. Both groups also worked on the memory task in a wake condition. Recognition accuracy was significantly better for negative than for neutral stimuli and better after the sleep than the wake condition. There was, however, no difference in the recognition accuracy (neutral and emotional between the groups. In summary, our data suggest that REM-sleep deprivation was successful and that the resulting reduction of REM-sleep had no influence on memory consolidation whatsoever.

  3. Selective REM-sleep deprivation does not diminish emotional memory consolidation in young healthy subjects.

    Science.gov (United States)

    Morgenthaler, Jarste; Wiesner, Christian D; Hinze, Karoline; Abels, Lena C; Prehn-Kristensen, Alexander; Göder, Robert

    2014-01-01

    Sleep enhances memory consolidation and it has been hypothesized that rapid eye movement (REM) sleep in particular facilitates the consolidation of emotional memory. The aim of this study was to investigate this hypothesis using selective REM-sleep deprivation. We used a recognition memory task in which participants were shown negative and neutral pictures. Participants (N=29 healthy medical students) were separated into two groups (undisturbed sleep and selective REM-sleep deprived). Both groups also worked on the memory task in a wake condition. Recognition accuracy was significantly better for negative than for neutral stimuli and better after the sleep than the wake condition. There was, however, no difference in the recognition accuracy (neutral and emotional) between the groups. In summary, our data suggest that REM-sleep deprivation was successful and that the resulting reduction of REM-sleep had no influence on memory consolidation whatsoever.

  4. Heart rate response to post-learning stress predicts memory consolidation.

    Science.gov (United States)

    Larra, Mauro F; Schulz, André; Schilling, Thomas M; Ferreira de Sá, Diana S; Best, Daniel; Kozik, Bartlomiej; Schächinger, Hartmut

    2014-03-01

    Stressful experiences are often well remembered, an effect that has been explained by beta-adrenergic influences on memory consolidation. Here, we studied the impact of stress induced heart rate (HR) responses on memory consolidation in a post-learning stress paradigm. 206 male and female participants saw 52 happy and angry faces immediately before being exposed to the Cold Pressor Test or a non-stressful control procedure. Memory for the faces and their respective expression was tested twice, after 30 min and on the next day. High HR responders (in comparison to low HR responders as well as to the non-stressful control group) showed enhanced recognition memory one day after learning. Our results show that beta-adrenergic activation elicited shortly after learning enhances memory consolidation and that the stress induced HR response is a predictor for this effect. Copyright © 2013 Elsevier Inc. All rights reserved.

  5. Interaction between hippocampal and striatal systems predicts subsequent consolidation of motor sequence memory.

    Directory of Open Access Journals (Sweden)

    Geneviève Albouy

    Full Text Available The development of fast and reproducible motor behavior is a crucial human capacity. The aim of the present study was to address the relationship between the implementation of consistent behavior during initial training on a sequential motor task (the Finger Tapping Task and subsequent sleep-dependent motor sequence memory consolidation, using functional magnetic resonance imaging (fMRI and total sleep deprivation protocol. Our behavioral results indicated significant offline gains in performance speed after sleep whereas performance was only stabilized, but not enhanced, after sleep deprivation. At the cerebral level, we previously showed that responses in the caudate nucleus increase, in parallel to a decrease in its functional connectivity with frontal areas, as performance became more consistent. Here, the strength of the competitive interaction, assessed through functional connectivity analyses, between the caudate nucleus and hippocampo-frontal areas during initial training, predicted delayed gains in performance at retest in sleepers but not in sleep-deprived subjects. Moreover, during retest, responses increased in the hippocampus and medial prefrontal cortex in sleepers whereas in sleep-deprived subjects, responses increased in the putamen and cingulate cortex. Our results suggest that the strength of the competitive interplay between the striatum and the hippocampus, participating in the implementation of consistent motor behavior during initial training, conditions subsequent motor sequence memory consolidation. The latter process appears to be supported by a reorganisation of cerebral activity in hippocampo-neocortical networks after sleep.

  6. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy.

    Science.gov (United States)

    Tramoni, Eve; Felician, Olivier; Barbeau, Emmanuel J; Guedj, Eric; Guye, Maxime; Bartolomei, Fabrice; Ceccaldi, Mathieu

    2011-03-01

    Several experiments carried out with a subset of patients with temporal lobe epilepsy have demonstrated normal memory performance at standard delays of recall (i.e. minutes to hours) but impaired performance over longer delays (i.e. days or weeks), suggesting altered long-term consolidation mechanisms. These mechanisms were specifically investigated in a group of five adult-onset pharmaco-sensitive patients with temporal lobe epilepsy, exhibiting severe episodic memory complaints despite normal performance at standardized memory assessment. In a first experiment, the magnitude of autobiographical memory loss was evaluated using retrograde personal memory tasks based on verbal and visual cues. In both conditions, results showed an unusual U-shaped pattern of personal memory impairment, encompassing most of the patients' life, sparing however, periods of the childhood, early adulthood and past several weeks. This profile was suggestive of a long-term consolidation impairment of personal episodes, adequately consolidated over 'short-term' delays but gradually forgotten thereafter. Therefore, in a subsequent experiment, patients were submitted to a protocol specifically devised to investigate short and long-term consolidation of contextually-bound experiences (episodic memory) and context-free information (semantic knowledge and single-items). In the short term (1 h), performance at both contextually-free and contextually-bound memory tasks was intact. After a 6-week delay, however, contextually-bound memory performance was impaired while contextually-free memory performance remained preserved. This effect was independent of task difficulty and the modality of retrieval (recall and recognition). Neuroimaging studies revealed the presence of mild metabolic changes within medial temporal lobe structures. Taken together, these results show the existence of different consolidation systems within declarative memory. They suggest that mild medial temporal lobe dysfunction

  7. Histone H2A.Z subunit exchange controls consolidation of recent and remote memory.

    Science.gov (United States)

    Zovkic, Iva B; Paulukaitis, Brynna S; Day, Jeremy J; Etikala, Deepa M; Sweatt, J David

    2014-11-27

    Memory formation is a multi-stage process that initially requires cellular consolidation in the hippocampus, after which memories are downloaded to the cortex for maintenance, in a process termed systems consolidation. Epigenetic mechanisms regulate both types of consolidation, but histone variant exchange, in which canonical histones are replaced with their variant counterparts, is an entire branch of epigenetics that has received limited attention in the brain and has never, to our knowledge, been studied in relation to cognitive function. Here we show that histone H2A.Z, a variant of histone H2A, is actively exchanged in response to fear conditioning in the hippocampus and the cortex, where it mediates gene expression and restrains the formation of recent and remote memory. Our data provide evidence for H2A.Z involvement in cognitive function and specifically implicate H2A.Z as a negative regulator of hippocampal consolidation and systems consolidation, probably through downstream effects on gene expression. Moreover, alterations in H2A.Z binding at later stages of systems consolidation suggest that this histone has the capacity to mediate stable molecular modifications required for memory retention. Overall, our data introduce histone variant exchange as a novel mechanism contributing to the molecular basis of cognitive function and implicate H2A.Z as a potential therapeutic target for memory disorders.

  8. Circadian modulation of consolidated memory retrieval following sleep deprivation in Drosophila.

    Science.gov (United States)

    Le Glou, Eric; Seugnet, Laurent; Shaw, Paul J; Preat, Thomas; Goguel, Valérie

    2012-10-01

    Several lines of evidence indicate that sleep plays a critical role in learning and memory. The aim of this study was to evaluate anesthesia resistant memory following sleep deprivation in Drosophila. Four to 16 h after aversive olfactory training, flies were sleep deprived for 4 h. Memory was assessed 24 h after training. Training, sleep deprivation, and memory tests were performed at different times during the day to evaluate the importance of the time of day for memory formation. The role of circadian rhythms was further evaluated using circadian clock mutants. Memory was disrupted when flies were exposed to 4 h of sleep deprivation during the consolidation phase. Interestingly, normal memory was observed following sleep deprivation when the memory test was performed during the 2 h preceding lights-off, a period characterized by maximum wake in flies. We also show that anesthesia resistant memory was less sensitive to sleep deprivation in flies with disrupted circadian rhythms. Our results indicate that anesthesia resistant memory, a consolidated memory less costly than long-term memory, is sensitive to sleep deprivation. In addition, we provide evidence that circadian factors influence memory vulnerability to sleep deprivation and memory retrieval. Taken together, the data show that memories weakened by sleep deprivation can be retrieved if the animals are tested at the optimal circadian time.

  9. Effects of acute methamphetamine on emotional memory formation in humans: encoding vs consolidation.

    Science.gov (United States)

    Ballard, Michael E; Weafer, Jessica; Gallo, David A; de Wit, Harriet

    2015-01-01

    Understanding how stimulant drugs affect memory is important for understanding their addictive potential. Here we examined the effects of acute d-methamphetamine (METH), administered either before (encoding phase) or immediately after (consolidation phase) study on memory for emotional and neutral images in healthy humans. Young adult volunteers (N = 60) were randomly assigned to either an encoding group (N = 29) or a consolidation group (N = 31). Across three experimental sessions, they received placebo and two doses of METH (10, 20 mg) either 45 min before (encoding) or immediately after (consolidation) viewing pictures of emotionally positive, neutral, and negative scenes. Memory for the pictures was tested two days later, under drug-free conditions. Half of the sample reported sleep disturbances following the high dose of METH, which affected their memory performance. Therefore, participants were classified as poor sleepers (less than 6 hours; n = 29) or adequate sleepers (6 or more hours; n = 31) prior to analyses. For adequate sleepers, METH (20 mg) administered before encoding significantly improved memory accuracy relative to placebo, especially for emotional (positive and negative), compared to neutral, stimuli. For poor sleepers in the encoding group, METH impaired memory. METH did not affect memory in the consolidation group regardless of sleep quality. These results extend previous findings showing that METH can enhance memory for salient emotional stimuli but only if it is present at the time of study, where it can affect both encoding and consolidation. METH does not appear to facilitate consolidation if administered after encoding. The study also demonstrates the important role of sleep in memory studies.

  10. Effects of acute methamphetamine on emotional memory formation in humans: encoding vs consolidation.

    Directory of Open Access Journals (Sweden)

    Michael E Ballard

    Full Text Available Understanding how stimulant drugs affect memory is important for understanding their addictive potential. Here we examined the effects of acute d-methamphetamine (METH, administered either before (encoding phase or immediately after (consolidation phase study on memory for emotional and neutral images in healthy humans. Young adult volunteers (N = 60 were randomly assigned to either an encoding group (N = 29 or a consolidation group (N = 31. Across three experimental sessions, they received placebo and two doses of METH (10, 20 mg either 45 min before (encoding or immediately after (consolidation viewing pictures of emotionally positive, neutral, and negative scenes. Memory for the pictures was tested two days later, under drug-free conditions. Half of the sample reported sleep disturbances following the high dose of METH, which affected their memory performance. Therefore, participants were classified as poor sleepers (less than 6 hours; n = 29 or adequate sleepers (6 or more hours; n = 31 prior to analyses. For adequate sleepers, METH (20 mg administered before encoding significantly improved memory accuracy relative to placebo, especially for emotional (positive and negative, compared to neutral, stimuli. For poor sleepers in the encoding group, METH impaired memory. METH did not affect memory in the consolidation group regardless of sleep quality. These results extend previous findings showing that METH can enhance memory for salient emotional stimuli but only if it is present at the time of study, where it can affect both encoding and consolidation. METH does not appear to facilitate consolidation if administered after encoding. The study also demonstrates the important role of sleep in memory studies.

  11. The role of histamine receptors in the consolidation of object recognition memory.

    Science.gov (United States)

    da Silveira, Clarice Krás Borges; Furini, Cristiane R G; Benetti, Fernando; Monteiro, Siomara da Cruz; Izquierdo, Ivan

    2013-07-01

    Findings have shown that histamine receptors in the hippocampus modulate the acquisition and extinction of fear motivated learning. In order to determine the role of hippocampal histaminergic receptors on recognition memory, adult male Wistar rats with indwelling infusion cannulae stereotaxically placed in the CA1 region of dorsal hippocampus were trained in an object recognition learning task involving exposure to two different stimulus objects in an enclosed environment. In the test session, one of the objects presented during training was replaced by a novel one. Recognition memory retention was assessed 24 h after training by comparing the time spent in exploration (sniffing and touching) of the known object with that of the novel one. When infused in the CA1 region immediately, 30, 120 or 360 min posttraining, the H1-receptor antagonist, pyrilamine, the H2-receptor antagonist, ranitidine, and the H3-receptor agonist, imetit, blocked long-term memory retention in a time dependent manner (30-120 min) without affecting general exploratory behavior, anxiety state or hippocampal function. Our data indicate that histaminergic system modulates consolidation of object recognition memory through H1, H2 and H3 receptors.

  12. Sleep, Dreams, and Memory Consolidation: The Role of the Stress Hormone Cortisol

    Science.gov (United States)

    Payne, Jessica D.; Nadel, Lynn

    2004-01-01

    We discuss the relationship between sleep, dreams, and memory, proposing that the content of dreams reflects aspects of memory consolidation taking place during the different stages of sleep. Although we acknowledge the likely involvement of various neuromodulators in these phenomena, we focus on the hormone cortisol, which is known to exert…

  13. Histone Acetylation is Recruited in Consolidation as a Molecular Feature of Stronger Memories

    Science.gov (United States)

    Federman, Noel; Fustinana, Maria Sol; Romano, Arturo

    2009-01-01

    Gene expression is a key process for memory consolidation. Recently, the participation of epigenetic mechanisms like histone acetylation was evidenced in long-term memories. However, until now the training strength required and the persistence of the chromatin acetylation recruited are not well characterized. Here we studied whether histone…

  14. Peripheral bacterial endotoxin administration triggers both memory consolidation and reconsolidation deficits in mice.

    Science.gov (United States)

    Kranjac, Dinko; McLinden, Kristina A; Deodati, Lauren E; Papini, Mauricio R; Chumley, Michael J; Boehm, Gary W

    2012-01-01

    Peripherally administered inflammatory stimuli, such as lipopolysaccharide (LPS), induce the synthesis and release of proinflammatory cytokines and chemokines in the periphery and the central nervous system, and trigger a variety of neurobiological responses. Indeed, prior reports indicate that peripheral LPS administration in rats disrupts contextual fear memory consolidation processes, potentially due to elevated cytokine expression. We used a similar, but partially olfaction-based, contextual fear conditioning paradigm to examine the effects of LPS on memory consolidation and reconsolidation in mice. Additionally, interleukin-1β (IL-1β), brain-derived neurotrophic factor (BDNF), and zinc finger (Zif)-268 mRNA expression in the hippocampus and the cortex, along with peripheral cytokines and chemokines, were assessed. As hypothesized, LPS administered immediately or 2 h, but not 12 h, post-training impaired memory consolidation processes that support the storage of the conditioned contextual fear memory. Additionally, as hypothesized, LPS administered immediately following the fear memory trace reactivation session impaired memory reconsolidation processes. Four hours post-injection, both central cytokine and peripheral cytokine and chemokine levels were heightened in LPS-treated animals, with a simultaneous decrease in BDNF, but not Zif-268, mRNA. Collectively, these data reinforce prior work showing LPS- and cytokine-related effects on memory consolidation, and extend this work to memory reconsolidation.

  15. The Sensitivity of Memory Consolidation and Reconsolidation to Inhibitors of Protein Synthesis and Kinases: Computational Analysis

    Science.gov (United States)

    Zhang, Yili; Smolen, Paul; Baxter, Douglas A.; Byrne, John H.

    2010-01-01

    Memory consolidation and reconsolidation require kinase activation and protein synthesis. Blocking either process during or shortly after training or recall disrupts memory stabilization, which suggests the existence of a critical time window during which these processes are necessary. Using a computational model of kinase synthesis and…

  16. Fatty-acid binding proteins modulate sleep and enhance long-term memory consolidation in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jason R Gerstner

    Full Text Available Sleep is thought to be important for memory consolidation, since sleep deprivation has been shown to interfere with memory processing. However, the effects of augmenting sleep on memory formation are not well known, and testing the role of sleep in memory enhancement has been limited to pharmacological and behavioral approaches. Here we test the effect of overexpressing the brain-type fatty acid binding protein (Fabp7 on sleep and long-term memory (LTM formation in Drosophila melanogaster. Transgenic flies carrying the murine Fabp7 or the Drosophila homologue dFabp had reduced baseline sleep but normal LTM, while Fabp induction produced increases in both net sleep and LTM. We also define a post-training consolidation "window" that is sufficient for the observed Fabp-mediated memory enhancement. Since Fabp overexpression increases consolidated daytime sleep bouts, these data support a role for longer naps in improving memory and provide a novel role for lipid-binding proteins in regulating memory consolidation concurrently with changes in behavioral state.

  17. 76 FR 17381 - Battelle Memorial Institute, et al.; Notice of Consolidated Decision on Applications for Duty...

    Science.gov (United States)

    2011-03-29

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Battelle Memorial Institute, et al.; Notice of Consolidated Decision on...., Washington, DC. Docket Number: 10-045. Applicant: Battelle Memorial Institute, Richland, WA 99354. Instrument...

  18. CONSOLIDATING BATCH AND TRANSACTIONAL WORKLOADS USING DEPENDENCY STRUCTURE PRIORITIZATION

    Directory of Open Access Journals (Sweden)

    S.NIVETHITHA

    2013-04-01

    Full Text Available Organizations offer efficient services to their customers through cloud. These services can either be a batch or transactional workloads. To offer a real-time service, there comes a need to schedule these workloads in an efficient way. An idea to consolidate these workloads enables us to cut down the energy consumption and infrastructure cost. It will be harder to consolidate both these workloads due to the difference in their nature, performance goals and control mechanisms. The proposed work implements the concept of Dependency Structure Prioritization (DSP to assign priority to the job. This work tends to make effective resource utilization through reducing the number of job migration and missed deadline jobs by considering the deadline and the priority of the job as the most important evaluation factor.

  19. Enhanced Human Memory Consolidation With Post-Learning Stress: Interaction With the Degree of Arousal at Encoding

    OpenAIRE

    Cahill, Larry; Gorski, Lukasz; Le, Kathryn

    2003-01-01

    Abundant evidence indicates that endogenous stress hormones such as epinephrine and corticosterone modulate memory consolidation in animals. We recently provided the first demonstration that an endogenous stress hormone (epinephrine) can enhance human memory consolidation. However, these findings also suggested that post-learning stress hormone activation does not uniformly enhance memory for all recently acquired information; rather, that it interacts with the degree ...

  20. Protein Synthesis Underlies Post-Retrieval Memory Consolidation to a Restricted Degree Only when Updated Information Is Obtained

    Science.gov (United States)

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

    2005-01-01

    Consolidation theory proposes that through the synthesis of new proteins recently acquired memories are strengthened over time into a stable long-term memory trace. However, evidence has accumulated suggesting that retrieved memory is susceptible to disruption, seeming to consolidate again (reconsolidate) to be retained in long-term storage. Here…

  1. Motor memory in childhood: early expression of consolidation phase gains.

    Science.gov (United States)

    Ashtamker, Lilach; Karni, Avi

    2013-11-01

    Are children faster than adults in consolidating procedural knowledge? In adults, the expression of the full benefits of motor practice requires a few hours of consolidation and sleep. Here we show that, although the processes generating the delayed gains continued beyond the first few hours post-training, children expressed significant gains as early as 1 h post-training, in the awake state. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. The anticancer estrogen receptor antagonist tamoxifen impairs consolidation of inhibitory avoidance memory through estrogen receptor alpha.

    Science.gov (United States)

    Lichtenfels, Martina; Dornelles, Arethuza da Silva; Petry, Fernanda Dos Santos; Blank, Martina; de Farias, Caroline Brunetto; Roesler, Rafael; Schwartsmann, Gilberto

    2017-09-02

    Over two-thirds of women with breast cancer have positive tumors for hormone receptors, and these patients undergo treatment with endocrine therapy, tamoxifen being the most widely used agent. Despite being very effective in breast cancer treatment, tamoxifen is associated with side effects that include cognitive impairments. However, the specific aspects and mechanisms underlying these impairments remain to be characterized. Here, we have investigated the effects of tamoxifen and interaction with estrogen receptors on formation of memory for inhibitory avoidance conditioning in female rats. In the first experiment, Wistar female rats received a single oral dose of tamoxifen (1, 3, or 10 mg/kg) or saline by gavage immediately after training and were tested for memory consolidation 24 h after training. In the second experiment, rats received a single dose of 1 mg/kg tamoxifen or saline by gavage 3 h after training and were tested 24 h after training for memory consolidation. In the third experiment, rats received a subcutaneous injection with estrogen receptor α agonist or estrogen receptor beta agonist 30 min before the training. After training, rats received a single oral dose of tamoxifen 1 mg/kg or saline and were tested 24 h after training. In the fourth experiment, rats were trained and tested 24 h later. Immediately after test, rats received a single dose of tamoxifen (1 mg/kg) or saline by gavage and were given four additional daily test trials followed by a re-instatement. Tamoxifen at 1 mg/kg impaired memory consolidation when given immediately after training and the estrogen receptor alpha agonist improved the tamoxifen-related memory impairment. Moreover, tamoxifen impairs memory consolidation of the test. These findings indicate that estrogen receptors regulate the early phase of memory consolidation and the effects of tamoxifen on memory consolidation.

  3. 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.

  4. Sleep enhances false memories depending on general memory performance.

    Science.gov (United States)

    Diekelmann, Susanne; Born, Jan; Wagner, Ullrich

    2010-04-02

    Memory is subject to dynamic changes, sometimes giving rise to the formation of false memories due to biased processes of consolidation or retrieval. Sleep is known to benefit memory consolidation through an active reorganization of representations whereas acute sleep deprivation impairs retrieval functions. Here, we investigated whether sleep after learning and sleep deprivation at retrieval enhance the generation of false memories in a free recall test. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., "night", "dark", "coal", etc.), lacking the strongest common associate or theme word (here: "black"). Free recall was tested after 9h following a night of sleep, a night of wakefulness (sleep deprivation) or daytime wakefulness. Compared with memory performance after a retention period of daytime wakefulness, both post-learning nocturnal sleep as well as acute sleep deprivation at retrieval significantly enhanced false recall of theme words. However, these effects were only observed in subjects with low general memory performance. These data point to two different ways in which sleep affects false memory generation through semantic generalization: one acts during consolidation on the memory trace per se, presumably by active reorganization of the trace in the post-learning sleep period. The other is related to the recovery function of sleep and affects cognitive control processes of retrieval. Both effects are unmasked when the material is relatively weakly encoded.

  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 memory

  6. Acute Exercise and Motor Memory Consolidation: The Role of Exercise Timing

    OpenAIRE

    Richard Thomas; Mikkel Malling Beck; Rune Rasmussen Lind; Line Korsgaard Johnsen; Svend Sparre Geertsen; Lasse Christiansen; Christian Ritz; Marc Roig; Jesper Lundbye-Jensen

    2016-01-01

    High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acq...

  7. Daytime sleep enhances consolidation of the spatial but not motoric representation of motor sequence memory.

    Directory of Open Access Journals (Sweden)

    Geneviève Albouy

    Full Text Available Motor sequence learning is known to rely on more than a single process. As the skill develops with practice, two different representations of the sequence are formed: a goal representation built under spatial allocentric coordinates and a movement representation mediated through egocentric motor coordinates. This study aimed to explore the influence of daytime sleep (nap on consolidation of these two representations. Through the manipulation of an explicit finger sequence learning task and a transfer protocol, we show that both allocentric (spatial and egocentric (motor representations of the sequence can be isolated after initial training. Our results also demonstrate that nap favors the emergence of offline gains in performance for the allocentric, but not the egocentric representation, even after accounting for fatigue effects. Furthermore, sleep-dependent gains in performance observed for the allocentric representation are correlated with spindle density during non-rapid eye movement (NREM sleep of the post-training nap. In contrast, performance on the egocentric representation is only maintained, but not improved, regardless of the sleep/wake condition. These results suggest that motor sequence memory acquisition and consolidation involve distinct mechanisms that rely on sleep (and specifically, spindle or simple passage of time, depending respectively on whether the sequence is performed under allocentric or egocentric coordinates.

  8. Increased sleep fragmentation leads to impaired off-line consolidation of motor memories in humans.

    Directory of Open Access Journals (Sweden)

    Ina Djonlagic

    Full Text Available A growing literature supports a role for sleep after training in long-term memory consolidation and enhancement. Consequently, interrupted sleep should result in cognitive deficits. Recent evidence from an animal study indeed showed that optimal memory consolidation during sleep requires a certain amount of uninterrupted sleep. Sleep continuity is disrupted in various medical disorders. We compared performance on a motor sequence learning task (MST in relatively young subjects with obstructive sleep apnea (n = 16; apnea-hypopnea index 17.1±2.6/h [SEM] to a carefully matched control group (n = 15, apnea-hypopnea index 3.7±0.4/h, p<0.001. Apart from AHI, oxygen nadir and arousal index, there were no significant differences between groups in total sleep time, sleep efficiency and sleep architecture as well as subjective measures of sleepiness based on standard questionnaires. In addition performance on the psychomotor vigilance task (reaction time and lapses, which is highly sensitive to sleep deprivation showed no differences as well as initial learning performance during the training phase. However there was a significant difference in the primary outcome of immediate overnight improvement on the MST between the two groups (controls = 14.7±4%, patients = 1.1±3.6%; P = 0.023 as well as plateau performance (controls = 24.0±5.3%, patients = 10.1±2.0%; P = 0.017 and this difference was predicted by the arousal index (p = 0.02 rather than oxygen saturation (nadir and time below 90% saturation. Taken together, this outcome provides evidence that there is a clear minimum requirement of sleep continuity in humans to ensure optimal sleep dependent memory processes. It also provides important new information about the cognitive impact of obstructive sleep apnea and challenges its current definitions.

  9. Role of protein synthesis and DNA methylation in the consolidation and maintenance of long-term memory in Aplysia

    Science.gov (United States)

    Pearce, Kaycey; Cai, Diancai; Roberts, Adam C; Glanzman, David L

    2017-01-01

    Previously, we reported that long-term memory (LTM) in Aplysia can be reinstated by truncated (partial) training following its disruption by reconsolidation blockade and inhibition of PKM (Chen et al., 2014). Here, we report that LTM can be induced by partial training after disruption of original consolidation by protein synthesis inhibition (PSI) begun shortly after training. But when PSI occurs during training, partial training cannot subsequently establish LTM. Furthermore, we find that inhibition of DNA methyltransferase (DNMT), whether during training or shortly afterwards, blocks consolidation of LTM and prevents its subsequent induction by truncated training; moreover, later inhibition of DNMT eliminates consolidated LTM. Thus, the consolidation of LTM depends on two functionally distinct phases of protein synthesis: an early phase that appears to prime LTM; and a later phase whose successful completion is necessary for the normal expression of LTM. Both the consolidation and maintenance of LTM depend on DNA methylation. DOI: http://dx.doi.org/10.7554/eLife.18299.001 PMID:28067617

  10. The role of sleep in cognitive processing: focusing on memory consolidation.

    Science.gov (United States)

    Chambers, Alexis M

    2017-05-01

    Research indicates that sleep promotes various cognitive functions, such as decision-making, language, categorization, and memory. Of these, most work has focused on the influence of sleep on memory, with ample work showing that sleep enhances memory consolidation, a process that stores new memories in the brain over time. Recent psychological and neurophysiological research has vastly increased understanding of this process. Such work not only suggests that consolidation relies on plasticity-related mechanisms that reactivate and stabilize memory representations, but also that this process may be experimentally manipulated by methods that target which memory traces are reactivated during sleep. Furthermore, aside from memory storage capabilities, memory consolidation also appears to reorganize and integrate memories with preexisting knowledge, which may facilitate the discovery of underlying rules and associations that benefit other cognitive functioning, including problem solving and creativity. WIREs Cogn Sci 2017, 8:e1433. doi: 10.1002/wcs.1433 For further resources related to this article, please visit the WIREs website. © 2017 Wiley Periodicals, Inc.

  11. Insular Cortex Is Involved in Consolidation of Object Recognition Memory

    Science.gov (United States)

    Bermudez-Rattoni, Federico; Okuda, Shoki; Roozendaal, Benno; McGaugh, James L.

    2005-01-01

    Extensive evidence indicates that the insular cortex (IC), also termed gustatory cortex, is critically involved in conditioned taste aversion and taste recognition memory. Although most studies of the involvement of the IC in memory have investigated taste, there is some evidence that the IC is involved in memory that is not based on taste. In…

  12. Reward Retroactively Enhances Memory Consolidation for Related Items

    Science.gov (United States)

    Patil, Anuya; Murty, Vishnu P.; Dunsmoor, Joseph E.; Phelps, Elizabeth A.; Davachi, Lila

    2017-01-01

    Reward motivation has been shown to modulate episodic memory processes in order to support future adaptive behavior. However, for a memory system to be truly adaptive, it should enhance memory for rewarded events as well as for neutral events that may seem inconsequential at the time of encoding but can gain importance later. Here, we investigated…

  13. Reward Retroactively Enhances Memory Consolidation for Related Items

    Science.gov (United States)

    Patil, Anuya; Murty, Vishnu P.; Dunsmoor, Joseph E.; Phelps, Elizabeth A.; Davachi, Lila

    2017-01-01

    Reward motivation has been shown to modulate episodic memory processes in order to support future adaptive behavior. However, for a memory system to be truly adaptive, it should enhance memory for rewarded events as well as for neutral events that may seem inconsequential at the time of encoding but can gain importance later. Here, we investigated…

  14. 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.

  15. Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation within the Amygdala.

    Science.gov (United States)

    Aubry, Antonio V; Serrano, Peter A; Burghardt, Nesha S

    2016-01-01

    Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by which stress affects the amygdala and amygdala-dependent fear memories remain unclear. Here we review the literature on the enhancing effects of acute and chronic stress on the acquisition and/or consolidation of a fear memory, as measured by auditory Pavlovian fear conditioning, and discuss potential mechanisms by which these changes occur in the amygdala. We hypothesize that stress-mediated activation of glucocorticoid receptors (GR) and norepinephrine release within the amygdala leads to the mobilization of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors to the synapse, which underlies stress-induced increases in fear memory. We discuss the implications of this hypothesis for evaluating the effects of stress on extinction and for developing treatments for anxiety disorders. Understanding how stress-induced changes in glucocorticoid and norepinephrine signaling might converge to affect emotional learning by increasing the trafficking of AMPA receptors and enhancing amygdala excitability is a promising area for future research.

  16. Molecular Mechanisms of Stress-Induced Increases in Fear Memory Consolidation Within the Amygdala

    Directory of Open Access Journals (Sweden)

    Antonio Aubry

    2016-10-01

    Full Text Available Stress can significantly impact brain function and increase the risk for developing various psychiatric disorders. Many of the brain regions that are implicated in psychiatric disorders and are vulnerable to the effects of stress are also involved in mediating emotional learning. Emotional learning has been a subject of intense investigation for the past 30 years, with the vast majority of studies focusing on the amygdala and its role in associative fear learning. However, the mechanisms by which stress affects the amygdala and amygdala-dependent fear memories remain unclear. Here we review the literature on the enhancing effects of acute and chronic stress on the acquisition and/or consolidation of a fear memory, as measured by auditory Pavlovian fear conditioning, and discuss potential mechanisms by which these changes occur in the amygdala. We hypothesize that stress-mediated activation of glucocorticoid receptors (GR and norepinephrine release within the amygdala leads to the mobilization of AMPA receptors to the synapse, which underlies stress-induced increases in fear memory. We discuss the implications of this hypothesis for evaluating the effects of stress on extinction and for developing treatments for anxiety disorders. Understanding how stress-induced changes in glucocorticoid and norepinephrine signaling might converge to affect emotional learning by increasing the trafficking of AMPA receptors and enhancing amygdala excitability is a promising area for future research.

  17. M1 muscarinic acetylcholine receptor agonism alters sleep without affecting memory consolidation.

    Science.gov (United States)

    Nissen, Christoph; Power, Ann E; Nofzinger, Eric A; Feige, Bernd; Voderholzer, Ulrich; Kloepfer, Corinna; Waldheim, Bernhard; Radosa, Marc-Philipp; Berger, Mathias; Riemann, Dieter

    2006-11-01

    Preclinical studies have implicated cholinergic neurotransmission, specifically M1 muscarinic acetylcholine receptor (mAChR) activation, in sleep-associated memory consolidation. In the present study, we investigated the effects of administering the direct M1 mAChR agonist RS-86 on pre-post sleep memory consolidation. Twenty healthy human participants were tested in a declarative word-list task and a procedural mirror-tracing task. RS-86 significantly reduced rapid eye movement (REM) sleep latency and slow wave sleep (SWS) duration in comparison with placebo. Presleep acquisition and postsleep recall rates were within the expected ranges. However, recall rates in both tasks were almost identical for the RS-86 and placebo conditions. These results indicate that selective M1 mAChR activation in healthy humans has no clinically relevant effect on pre-post sleep consolidation of declarative or procedural memories at a dose that reduces REM sleep latency and SWS duration.

  18. The role of sleep and sleep deprivation in consolidating fear memories.

    Science.gov (United States)

    Menz, M M; Rihm, J S; Salari, N; Born, J; Kalisch, R; Pape, H C; Marshall, L; Büchel, C

    2013-07-15

    Sleep, in particular REM sleep, has been shown to improve the consolidation of emotional memories. Here, we investigated the role of sleep and sleep deprivation on the consolidation of fear memories and underlying neuronal mechanisms. We employed a Pavlovian fear conditioning paradigm either followed by a night of polysomnographically monitored sleep, or wakefulness in forty healthy participants. Recall of learned fear was better after sleep, as indicated by stronger explicitly perceived anxiety and autonomous nervous responses. These effects were positively correlated with the preceding time spent in REM sleep and paralleled by activation of the basolateral amygdala. These findings suggest REM sleep-associated consolidation of fear memory in the human amygdala. In view of the critical participation of fear learning mechanisms in the etiology of anxiety and post-traumatic stress disorder, deprivation of REM sleep after exposure to distressing events is an interesting target for further investigation.

  19. No Associations between Interindividual Differences in Sleep Parameters and Episodic Memory Consolidation

    Science.gov (United States)

    Ackermann, Sandra; Hartmann, Francina; Papassotiropoulos, Andreas; de Quervain, Dominique J.F.; Rasch, Björn

    2015-01-01

    Study Objectives: Sleep and memory are stable and heritable traits that strongly differ between individuals. Sleep benefits memory consolidation, and the amount of slow wave sleep, sleep spindles, and rapid eye movement sleep have been repeatedly identified as reliable predictors for the amount of declarative and/or emotional memories retrieved after a consolidation period filled with sleep. These studies typically encompass small sample sizes, increasing the probability of overestimating the real association strength. In a large sample we tested whether individual differences in sleep are predictive for individual differences in memory for emotional and neutral pictures. Design: Between-subject design. Setting: Cognitive testing took place at the University of Basel, Switzerland. Sleep was recorded at participants' homes, using portable electroencephalograph-recording devices. Participants: Nine hundred-twenty-nine healthy young participants (mean age 22.48 ± 3.60 y standard deviation). Interventions: None. Measurements and results: In striking contrast to our expectations as well as numerous previous findings, we did not find any significant correlations between sleep and memory consolidation for pictorial stimuli. Conclusions: Our results indicate that individual differences in sleep are much less predictive for pictorial memory processes than previously assumed and suggest that previous studies using small sample sizes might have overestimated the association strength between sleep stage duration and pictorial memory performance. Future studies need to determine whether intraindividual differences rather than interindividual differences in sleep stage duration might be more predictive for the consolidation of emotional and neutral pictures during sleep. Citation: Ackermann S, Hartmann F, Papassotiropoulos A, de Quervain DJF, Rasch B. No associations between interindividual differences in sleep parameters and episodic memory consolidation. SLEEP 2015;38(6):951

  20. Procedural Memory Consolidation in the Performance of Brief Keyboard Sequences

    Science.gov (United States)

    Duke, Robert A.; Davis, Carla M.

    2006-01-01

    Using two sequential key press sequences, we tested the extent to which subjects' performance on a digital piano keyboard changed between the end of training and retest on subsequent days. We found consistent, significant improvements attributable to sleep-based consolidation effects, indicating that learning continued after the cessation of…

  1. Timing matters: negative emotion elicited 5 min but not 30 min or 45 min after learning enhances consolidation of internal-monitoring source memory.

    Science.gov (United States)

    Wang, Bo; Bukuan, Sun

    2015-05-01

    Two experiments examined the time-dependent effects of negative emotion on consolidation of item and internal-monitoring source memory. In Experiment 1, participants (n=121) learned a list of words. They were asked to read aloud half of the words and to think about the remaining half. They were instructed to memorize each word and its associative cognitive operation ("reading" versus "thinking"). Immediately following learning they conducted free recall and then watched a 3-min either neutral or negative video clip when 5 min, 30 min or 45 min had elapsed after learning. Twenty-four hours later they returned to take surprise tests for item and source memory. Experiment 2 was similar to Experiment 1 except that participants, without conducting an immediate test of free recall, took tests of source memory for all encoded words both immediately and 24 h after learning. Experiment 1 showed that negative emotion enhanced consolidation of item memory (as measured by retention ratio of free recall) regardless of delay of emotion elicitation and that negative emotion enhanced consolidation of source memory when it was elicited at a 5 min delay but reduced consolidation of source memory when it was elicited at a 30 min delay; when elicited at a 45 min delay, negative emotion had little effect. Furthermore, Experiment 2 replicated the enhancement effect on source memory in the 5 min delay even when participants were tested on all the encoded words. The current study partially replicated prior studies on item memory and extends the literature by providing evidence for a time-dependent effect of negative emotion on consolidation of source memory based on internal monitoring.

  2. Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.

    Science.gov (United States)

    Gibbs, Marie E; Hutchinson, Dana S; Summers, Roger J

    2008-09-01

    Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.

  3. Endocannabinoid Signaling within the Basolateral Amygdala Integrates Multiple Stress Hormone Effects on Memory Consolidation

    Science.gov (United States)

    Atsak, Piray; Hauer, Daniela; Campolongo, Patrizia; Schelling, Gustav; Fornari, Raquel V; Roozendaal, Benno

    2015-01-01

    Glucocorticoid hormones are known to act synergistically with other stress-activated neuromodulatory systems, such as norepinephrine and corticotropin-releasing factor (CRF), within the basolateral complex of the amygdala (BLA) to induce optimal strengthening of the consolidation of long-term memory of emotionally arousing experiences. However, as the onset of these glucocorticoid actions appear often too rapid to be explained by genomic regulation, the neurobiological mechanism of how glucocorticoids could modify the memory-enhancing properties of norepinephrine and CRF remained elusive. Here, we show that the endocannabinoid system, a rapidly activated retrograde messenger system, is a primary route mediating the actions of glucocorticoids, via a glucocorticoid receptor on the cell surface, on BLA neural plasticity and memory consolidation. Furthermore, glucocorticoids recruit downstream endocannabinoid activity within the BLA to interact with both the norepinephrine and CRF systems in enhancing memory consolidation. These findings have important implications for understanding the fine-tuned crosstalk between multiple stress hormone systems in the coordination of (mal)adaptive stress and emotional arousal effects on neural plasticity and memory consolidation. PMID:25547713

  4. Molecular mechanisms underlying memory consolidation of taste information in the cortex

    Directory of Open Access Journals (Sweden)

    Shunit eGal-Ben-Ari

    2012-01-01

    Full Text Available The senses of taste and odor are both chemical senses. However, whereas an organism can detect an odor at a relatively long distance from its source, taste serves as the ultimate proximate gatekeeper of food intake: it helps in avoiding poisons and consuming beneficial substances. The automatic reaction to a given taste has been developed during evolution and is well adapted to conditions that may occur with high probability during the lifetime of an organism. However, in addition to this automatic reaction, animals can learn and remember tastes, together with their positive or negative values, with high precision and in light of minimal experience. This ability of mammalians to learn and remember tastes has been studied extensively in rodents through application of reasonably simple and well defined behavioral paradigms. The learning process follows a temporal continuum similar to those of other memories: acquisition, consolidation, retrieval, relearning, and reconsolidation. Moreover, inhibiting protein synthesis in the gustatory cortex specifically affects the consolidation phase of taste memory, i.e., the transformation of short- to long-term memory, in keeping with the general biochemical definition of memory consolidation. This review aims to present a general background of taste learning, and to focus on recent findings regarding the molecular mechanisms underlying taste memory consolidation in the gustatory cortex. Specifically, the role of neurotransmitters, meuromodulators, immediate early genes, and translation regulation are addressed.

  5. Sleep to find your way: the role of sleep in the consolidation of memory for navigation in humans.

    Science.gov (United States)

    Ferrara, Michele; Iaria, Giuseppe; Tempesta, Daniela; Curcio, Giuseppe; Moroni, Fabio; Marzano, Cristina; De Gennaro, Luigi; Pacitti, Claudio

    2008-01-01

    Although a large body of evidence indicates that sleep plays an important role in learning and memory processes, the actual existence of a sleep-dependent spatial memory consolidation has been not firmly established. Here, by using a computerized 3D virtual navigation tool, we were able to show that topographical orientation in humans largely benefits from sleep after learning, while 10 h of wakefulness during the daytime do not exert similar beneficial effects. In particular, navigation performance enhancement needs sleep in the first post-training night, and no further improvements were seen after a second night of sleep. On the other hand, sleep deprivation hinders any performance enhancement and exerts a proactive disruption of spatial memory consolidation, since recovery sleep do not revert its effects. Spatial memory performance does not benefit from the simple passage of time, and a period of wakefulness between learning and sleep does not seem to have the role of stabilizing memory traces. In conclusion, our results indicate that spatial performance improvement is observed only when learning is followed by a period of sleep, regardless of the retention interval length.

  6. Acute exercise and motor memory consolidation: Does exercise type play a role?

    Science.gov (United States)

    Thomas, R; Flindtgaard, M; Skriver, K; Geertsen, S S; Christiansen, L; Korsgaard Johnsen, L; Busk, D V P; Bojsen-Møller, E; Madsen, M J; Ritz, C; Roig, M; Lundbye-Jensen, J

    2016-10-27

    A single bout of high-intensity exercise can augment off-line gains in skills acquired during motor practice. It is currently unknown if the type of physical exercise influences the effect on motor skill consolidation. This study investigated the effect of three types of high-intensity exercise following visuomotor skill acquisition on the retention of motor memory in 40 young (25.3 ±3.6 years), able-bodied male participants randomly assigned to one of four groups either performing strength training (STR), circuit training (CT), indoor hockey (HOC) or rest (CON). Retention tests of the motor skill were performed 1 (R1h) and 24 h (R1d) post acquisition. For all exercise groups, mean motor performance scores decreased at R1h compared to post acquisition (POST) level; STR (P = 0.018), CT (P = 0.02), HOC (P = 0.014) and performance scores decreased for CT compared to CON (P = 0.049). Mean performance scores increased from POST to R1d for all exercise groups; STR (P = 0.010), CT (P = 0.020), HOC (P = 0.007) while performance scores for CON decreased (P = 0.043). Changes in motor performance were thus greater for STR (P = 0.006), CT (P exercise can lead to a decrease in motor performance assessed shortly after motor skill practice (R1h), but enhances offline effects promoting long-term retention (R1d). Given that different exercise modalities produced similar positive off-line effects on motor memory, we conclude that exercise-induced effects beneficial to consolidation appear to depend primarily on the physiological stimulus rather than type of exercise and movements employed.

  7. Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Jobim, P.F.C., E-mail: pjobim@uol.com.br [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Santos, C.E.I. dos [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Maurmann, N.; Reolon, G.K. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Debastiani, R. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Pedroso, T.R.; Carvalho, L.M. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Dias, J.F. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil)

    2014-08-01

    It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models.

  8. Sleep directly following learning benefits consolidation of spatial associative memory

    NARCIS (Netherlands)

    Talamini, L.M.; Nieuwenhuis, I.L.C.; Takashima, A.; Jensen, O.

    2008-01-01

    The last decade has brought forth convincing evidence for a role of sleep in non-declarative memory. A similar function of sleep in episodic memory is supported by various correlational studies, but direct evidence is limited. Here we show that cued recall of face-location associations is significan

  9. Sleep directly following learning benefits consolidation of spatial associative memory

    NARCIS (Netherlands)

    Talamini, L.M.; Nieuwenhuis, I.L.C.; Takashima, A.

    2008-01-01

    The last decade has brought forth convincing evidence for a role of sleep in non-declarative memory. A similar function of sleep in episodic memory is supported by various correlational studies, but direct evidence is limited. Here we show that cued recall of face–location associations is significan

  10. Effects of an interleukin-1 receptor antagonist on human sleep, sleep-associated memory consolidation, and blood monocytes.

    Science.gov (United States)

    Schmidt, Eva-Maria; Linz, Barbara; Diekelmann, Susanne; Besedovsky, Luciana; Lange, Tanja; Born, Jan

    2015-07-01

    Pro-inflammatory cytokines like interleukin-1 beta (IL-1) are major players in the interaction between the immune system and the central nervous system. Various animal studies report a sleep-promoting effect of IL-1 leading to enhanced slow wave sleep (SWS). Moreover, this cytokine was shown to affect hippocampus-dependent memory. However, the role of IL-1 in human sleep and memory is not yet understood. We administered the synthetic IL-1 receptor antagonist anakinra (IL-1ra) in healthy humans (100mg, subcutaneously, before sleep; n=16) to investigate the role of IL-1 signaling in sleep regulation and sleep-dependent declarative memory consolidation. Inasmuch monocytes have been considered a model for central nervous microglia, we monitored cytokine production in classical and non-classical blood monocytes to gain clues about how central nervous effects of IL-1ra are conveyed. Contrary to our expectation, IL-1ra increased EEG slow wave activity during SWS and non-rapid eye movement (NonREM) sleep, indicating a deepening of sleep, while sleep-associated memory consolidation remained unchanged. Moreover, IL-1ra slightly increased prolactin and reduced cortisol levels during sleep. Production of IL-1 by classical monocytes was diminished after IL-1ra. The discrepancy to findings in animal studies might reflect species differences and underlines the importance of studying cytokine effects in humans.

  11. The temporal locus of the interaction between working memory consolidation and the attentional blink.

    Science.gov (United States)

    Akyürek, Elkan G; Leszczyński, Marcin; Schubö, Anna

    2010-11-01

    An increase in concurrent working memory load has been shown to amplify the attentional blink. The present study investigated the temporal locus of this phenomenon, by using a dual rapid serial visual presentation paradigm that enabled the measurement of lateralized event-related potentials. The P3 component was shown to be affected by both working memory load and the lag between the target stimuli, consistent with current models of temporal attention and a functional explanation of the P3 in terms of memory consolidation. P3 amplitude was reduced for short target lags and high memory loads. The P2 component was affected by lag only, and not memory load. Importantly, the N2pc component was modulated also by both lag and memory load. The results showed that early attentional processing (as marked by the N2pc) was suppressed by increased involvement of working memory, a phenomenon not well predicted by many current theories of temporal attention.

  12. Consolidation in older adults depends upon competition between resting-state networks

    Directory of Open Access Journals (Sweden)

    Heidi IL Jacobs

    2015-01-01

    Full Text Available Memory encoding and retrieval problems are inherent to aging. To date, however, the effect of aging upon the neural correlates of forming memory traces remains poorly understood. Resting-state fMRI connectivity can be used to investigate initial consolidation. We compared within and between network connectivity differences between healthy young and older participants before encoding, after encoding and before retrieval by means of resting-state fMRI. Alterations over time in the between-network connectivity analyses correlated with retrieval performance, whereas within-network connectivity did not: a higher level of negative coupling or competition between the default mode and the executive networks during the after encoding condition was associated with increased retrieval performance in the older adults, but not in the young group. Data suggest that the effective formation of memory traces depends on an age-dependent, dynamic reorganization of the interaction between multiple, large-scale functional networks. Our findings demonstrate that a cross-network based approach can further the understanding of the neural underpinnings of aging- associated memory decline.

  13. Declarative and non-declarative memory consolidation in children with sleep disorder

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    Eszter eCsabi

    2016-01-01

    Full Text Available Healthy sleep is essential in children’s cognitive, behavioral, and emotional development. However, remarkably little is known about the influence of sleep disorders on different memory processes in childhood. Such data could give us a deeper insight into the effect of sleep on the developing brain and memory functions and how the relationship between sleep and memory changes from childhood to adulthood. In the present study we examined the effect of sleep disorder on declarative and non-declarative memory consolidation by testing children with sleep-disordered breathing (SDB which is characterized by disrupted sleep structure. We used a story recall task to measure declarative memory and Alternating Serial Reaction Time (ASRT task to assess non-declarative memory. This task enables us to measure two aspects of non-declarative memory, namely general motor skill learning and sequence-specific learning. There were two sessions: a learning phase and a testing phase, separated by a 12-hour offline period with sleep. Our data showed that children with SDB exhibited a generally lower declarative memory performance both in the learning and testing phase; however, both the SDB and control groups exhibited retention of the previously recalled items after the offline period. Here we showed intact non-declarative consolidation in SDB group in both sequence-specific and general motor skill. These findings suggest that sleep disorders in childhood have a differential effect on different memory processes (online vs. offline and give us insight into how sleep disturbances affects developing brain.

  14. Enhancing memory performance after organic brain disease relies on retrieval processes rather than encoding or consolidation.

    Science.gov (United States)

    Hildebrandt, Helmut; Gehrmann, Annika; Modden, Claudia; Eling, Paul

    2011-02-01

    Neuropsychological rehabilitation of memory performance is still a controversial topic, and rehabilitation studies have not analyzed to which stage of memory processing (encoding, consolidation, or retrieval) enhancement may be attributed. We first examined the efficacy of a computer training program for stroke patients, based on a previous study (Hildebrandt, Clausing, Janssen, & Modden, 2007a) for memory-impaired patients of a rehabilitation unit and compared it with the standard group treatment. In a second randomized controlled experiment, we trained two groups of 15 patients with mild to moderate memory disorders, caused by organic brain lesions, with the same two treatment approaches. We used several standard tests to analyze improvement of memory functions, focusing on separate parameters for encoding, consolidation, and retrieval. We developed for that purpose a new word-list learning test, which allowed assessment of response to novelty and a systematic comparison of free recall after learning of semantically structured and nonstructured word lists. The first treatment experiment showed significant improvement of verbal learning for patients treated with the computer software program. The second experiment showed that memory improvement was based exclusively on retrieval processes, whereas no specific change was found for encoding and consolidation. However, the two groups of the second experiment showed no significant differences for the treatment, although the absolute scores pointed in the same direction as in the first experiment.

  15. The role of sleep in declarative memory consolidation--direct evidence by intracranial EEG.

    Science.gov (United States)

    Axmacher, Nikolai; Haupt, Sven; Fernández, Guillén; Elger, Christian E; Fell, Juergen

    2008-03-01

    Two step theories of memory formation assume that an initial learning phase is followed by a consolidation stage. Memory consolidation has been suggested to occur predominantly during sleep. Very recent findings, however, suggest that important steps in memory consolidation occur also during waking state but may become saturated after some time awake. Sleep, in this model, specifically favors restoration of synaptic plasticity and accelerated memory consolidation while asleep and briefly afterwards. To distinguish between these different views, we recorded intracranial electroencephalograms from the hippocampus and rhinal cortex of human subjects while they retrieved information acquired either before or after a "nap" in the afternoon or on a control day without nap. Reaction times, hippocampal event-related potentials, and oscillatory gamma activity indicated a temporal gradient of hippocampal involvement in information retrieval on the control day, suggesting hippocampal-neocortical information transfer during waking state. On the day with nap, retrieval of recent items that were encoded briefly after the nap did not involve the hippocampus to a higher degree than retrieval of items encoded before the nap. These results suggest that sleep facilitates rapid processing through the hippocampus but is not necessary for information transfer into the neocortex per se.

  16. Consolidation differentially modulates schema effects on memory for items and associations

    NARCIS (Netherlands)

    Kesteren, M.T. van; Rijpkema, M.J.P.; Ruiter, D.J.; Fernandez, G.S.E.

    2013-01-01

    Newly learned information that is congruent with a preexisting schema is often better remembered than information that is incongruent. This schema effect on memory has previously been associated to more efficient encoding and consolidation mechanisms. However, this effect is not always consistently

  17. Blocking Dopaminergic Signaling Soon after Learning Impairs Memory Consolidation in Guinea Pigs.

    Directory of Open Access Journals (Sweden)

    Kiera-Nicole Lee

    Full Text Available Formation of episodic memories (i.e. remembered experiences requires a process called consolidation which involves communication between the neocortex and hippocampus. However, the neuromodulatory mechanisms underlying this neocortico-hippocampal communication are poorly understood. Here, we examined the involvement of dopamine D1 receptors (D1R and D2 receptors (D2R mediated signaling on memory consolidation using the Novel Object Recognition (NOR test. We conducted the tests in male Hartley guinea pigs and cognitive behaviors were assessed in customized Phenotyper home cages utilizing Ethovision XT software from Noldus enabled for the 3-point detection system (nose, center of the body, and rear. We found that acute intraperitoneal injections of either 0.25 mg/kg SCH23390 to block D1Rs or 1.0 mg/kg sulpiride to block D2Rs soon after acquisition (which involved familiarization to two similar objects attenuated subsequent discrimination for novel objects when tested after 5-hours in the NOR test. By contrast guinea pigs treated with saline showed robust discrimination for novel objects indicating normal operational processes undergirding memory consolidation. The data suggests that involvement of dopaminergic signaling is a key post-acquisition factor in modulating memory consolidation in guinea pigs.

  18. Differing Effects of Systemically Administered Rapamycin on Consolidation and Reconsolidation of Context vs. Cued Fear Memories

    Science.gov (United States)

    Glover, Ebony M.; Ressler, Kerry J.; Davis, Michael

    2010-01-01

    Rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR) kinase, has attracted interest as a possible prophylactic for post-traumatic stress disorder (PTSD)-associated fear memories. We report here that although rapamycin (40 mg/kg, i.p.) disrupted the consolidation and reconsolidation of fear-potentiated startle paradigm to a…

  19. The Consolidation of Object and Context Recognition Memory Involve Different Regions of the Temporal Lobe

    Science.gov (United States)

    Balderas, Israela; Rodriguez-Ortiz, Carlos J.; Salgado-Tonda, Paloma; Chavez-Hurtado, Julio; McGaugh, James L.; Bermudez-Rattoni, Federico

    2008-01-01

    These experiments investigated the involvement of several temporal lobe regions in consolidation of recognition memory. Anisomycin, a protein synthesis inhibitor, was infused into the hippocampus, perirhinal cortex, insular cortex, or basolateral amygdala of rats immediately after the sample phase of object or object-in-context recognition memory…

  20. Effects of Model Performances on Music Skill Acquisition and Overnight Memory Consolidation

    Science.gov (United States)

    Cash, Carla D.; Allen, Sarah E.; Simmons, Amy L.; Duke, Robert A.

    2014-01-01

    This study was designed to investigate the extent to which the presentation of an auditory model prior to learning a novel melody affects performance during active practice and the overnight consolidation of procedural memory. During evening training sessions, 32 nonpianist musicians practiced a 13-note keyboard melody with their left…

  1. Glucocorticoids in the dorsomedial striatum modulate the consolidation of spatial but not procedural memory

    NARCIS (Netherlands)

    Lozano, Y.R.; Serafin, N.; Prado-Alcala, R.A.; Roozendaal, B.; Quirarte, G.L.

    2013-01-01

    Glucocorticoid hormones are known to influence widely interconnected brain networks, thereby enhancing the consolidation of memory of several types of training experiences. In this network, the dorsal striatum plays an important role in transforming goal-directed behavior into habitual behavior. Man

  2. Effects of Model Performances on Music Skill Acquisition and Overnight Memory Consolidation

    Science.gov (United States)

    Cash, Carla D.; Allen, Sarah E.; Simmons, Amy L.; Duke, Robert A.

    2014-01-01

    This study was designed to investigate the extent to which the presentation of an auditory model prior to learning a novel melody affects performance during active practice and the overnight consolidation of procedural memory. During evening training sessions, 32 nonpianist musicians practiced a 13-note keyboard melody with their left…

  3. Reduced susceptibility to interference in the consolidation of motor memory before adolescence.

    Directory of Open Access Journals (Sweden)

    Shoshi Dorfberger

    Full Text Available Are children superior to adults in consolidating procedural memory? This notion has been tied to "critical," early life periods of increased brain plasticity. Here, using a motor sequence learning task, we show, in experiment 1, that a the rate of learning during a training session, b the gains accrued, without additional practice, within a 24 hours post-training interval (delayed consolidation gains, and c the long-term retention of these gains, were as effective in 9, 12 and 17-year-olds and comparable to those reported for adults. However, a follow-up experiment showed that the establishment of a memory trace for the trained sequence of movements was significantly more susceptible to interference by a subsequent motor learning experience (practicing a reversed movement sequence in the 17-year-olds compared to the 9 and 12-year-olds. Unlike the 17-year-olds, the younger age-groups showed significant delayed gains even after interference training. Altogether, our results indicate the existence of an effective consolidation phase in motor learning both before and after adolescence, with no childhood advantage in the learning or retention of a motor skill. However, the ability to co-consolidate different, successive motor experiences, demonstrated in both the 9 and 12-year-olds, diminishes after puberty, suggesting that a more selective memory consolidation process takes over from the childhood one. Only the adult consolidation process is gated by a recency effect, and in situations of multiple, clashing, experiences occurring within a short time-interval, adults may less effectively establish in memory experiences superseded by newer ones.

  4. Hippocampal sharp wave/ripples during sleep for consolidation of associative memory.

    Directory of Open Access Journals (Sweden)

    Wiâm Ramadan

    Full Text Available The beneficial effect of sleep on memory has been well-established by extensive research on humans, but the neurophysiological mechanisms remain a matter of speculation. This study addresses the hypothesis that the fast oscillations known as ripples recorded in the CA1 region of the hippocampus during slow wave sleep (SWS may provide a physiological substrate for long term memory consolidation. We trained rats in a spatial discrimination task to retrieve palatable reward in three fixed locations. Hippocampal local field potentials and cortical EEG were recorded for 2 h after each daily training session. There was an increase in ripple density during SWS after early training sessions, in both trained rats and in rats randomly rewarded for exploring the maze. In rats learning the place -reward association, there was a striking further significant increase in ripple density correlated with subsequent improvements in behavioral performance as the rat learned the spatial discrimination aspect of the task. The results corroborate others showing an experience-dependent increase in ripple activity and associated ensemble replay after exploratory activity, but in addition, for the first time, reveal a clear further increase in ripple activity related to associative learning based on spatial discrimination.

  5. Neuromodulatory signaling in hippocampus-dependent memory retrieval.

    Science.gov (United States)

    Thomas, Steven A

    2015-04-01

    Considerable advances have been made toward understanding the molecular signaling events that underlie memory acquisition and consolidation. In contrast, less is known about memory retrieval, despite its necessity for utilizing learned information. This review focuses on neuromodulatory and intracellular signaling events that underlie memory retrieval mediated by the hippocampus, for which the most information is currently available. Among neuromodulators, adrenergic signaling is required for the retrieval of various types of hippocampus-dependent memory. Although they contribute to acquisition and/or consolidation, cholinergic and dopaminergic signaling are generally not required for retrieval. Interestingly, while not required for retrieval, serotonergic and opioid signaling may actually constrain memory retrieval. Roles for histamine and non-opioid neuropeptides are currently unclear but possible. A critical effector of adrenergic signaling in retrieval is reduction of the slow afterhyperpolarization mediated by β1 receptors, cyclic AMP, protein kinase A, Epac, and possibly ERK. In contrast, stress and glucocorticoids impair retrieval by decreasing cyclic AMP, mediated in part by the activation of β2 -adrenergic receptors. Clinically, alterations in neuromodulatory signaling and in memory retrieval occur in Alzheimer's disease, Down syndrome, depression, and post-traumatic stress disorder, and recent evidence has begun to link changes in neuromodulatory signaling with effects on memory retrieval.

  6. Event-related nociceptive arousal enhances memory consolidation for neutral scenes.

    Science.gov (United States)

    Schwarze, Ulrike; Bingel, Ulrike; Sommer, Tobias

    2012-01-25

    The superior memory for emotional events has been attributed to the beneficial effects of noradrenaline released into the amygdala attributable to arousal. Noradrenaline mediates the effects of different hormones and neurotransmitters, including adrenal stress hormones on consolidation (McGaugh, 2004; Roozendaal et al., 2009). The majority of human fMRI studies of the enhancement of emotional memories contrasted successful encoding of emotionally arousing and neutral stimuli (LaBar and Cabeza, 2006; Murty et al., 2010). Recently, it was highlighted that emotional stimuli elicit not only arousal but also intensify cognitive processes that contribute to the enhanced memory. In particular, the enhanced use of selective attention as well as the greater distinctiveness and semantic relatedness of emotional stimuli influence memory formation (Talmi et al., 2007a). The present study aimed to explore the effects of arousal on memory formation independent of these cognitive factors in an event-related manner. Arousal was induced by the application of a nociceptive stimulus briefly after the presentation of neutral scenes. The results show a purely arousal-driven memory enhancement for the neutral scenes that differs in critical aspects from the superior memory for emotional stimuli. In particular, the enhancement was only evident after consolidation and exclusively based on an increase in item familiarity but not recollection. Moreover, successful memory formation for stimuli followed by arousal was correlated with activity in the parahippocampal cortex but not the amygdala, as is the case for emotional stimuli.

  7. Consciousness across Sleep and Wake: Discontinuity and Continuity of Memory Experiences As a Reflection of Consolidation Processes.

    Science.gov (United States)

    Horton, Caroline L

    2017-01-01

    The continuity hypothesis (1) posits that there is continuity, of some form, between waking and dreaming mentation. A recent body of work has provided convincing evidence for different aspects of continuity, for instance that some salient experiences from waking life seem to feature in dreams over others, with a particular role for emotional arousal as accompanying these experiences, both during waking and while asleep. However, discontinuities have been somewhat dismissed as being either a product of activation-synthesis, an error within the consciousness binding process during sleep, a methodological anomaly, or simply as yet unexplained. This paper presents an overview of discontinuity within dreaming and waking cognition, arguing that disruptions of consciousness are as common a feature of waking cognition as of dreaming cognition, and that processes of sleep-dependent memory consolidation of autobiographical experiences can in part account for some of the discontinuities of sleeping cognition in a functional way. By drawing upon evidence of the incorporation, fragmentation, and reorganization of memories within dreams, this paper proposes a model of discontinuity whereby the fragmentation of autobiographical and episodic memories during sleep, as part of the consolidation process, render salient aspects of those memories subsequently available for retrieval in isolation from their contextual features. As such discontinuity of consciousness in sleep is functional and normal.

  8. Activation of ERK/MAP kinase in the amygdala is required for memory consolidation of pavlovian fear conditioning.

    Science.gov (United States)

    Schafe, G E; Atkins, C M; Swank, M W; Bauer, E P; Sweatt, J D; LeDoux, J E

    2000-11-01

    Although much has been learned about the neurobiological mechanisms underlying Pavlovian fear conditioning at the systems and cellular levels, relatively little is known about the molecular mechanisms underlying fear memory consolidation. The present experiments evaluated the role of the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK/MAPK) signaling cascade in the amygdala during Pavlovian fear conditioning. We first show that ERK/MAPK is transiently activated-phosphorylated in the amygdala, specifically the lateral nucleus (LA), at 60 min, but not 15, 30, or 180 min, after conditioning, and that this activation is attributable to paired presentations of tone and shock rather than to nonassociative auditory stimulation, foot shock sensitization, or unpaired tone-shock presentations. We next show that infusions of U0126, an inhibitor of ERK/MAPK activation, aimed at the LA, dose-dependently impair long-term memory of Pavlovian fear conditioning but leaves short-term memory intact. Finally, we show that bath application of U0126 impairs long-term potentiation in the LA in vitro. Collectively, these results demonstrate that ERK/MAPK activation is necessary for both memory consolidation of Pavlovian fear conditioning and synaptic plasticity in the amygdala.

  9. Memory consolidation and amnesia modify 5-HT6 receptors expression in rat brain: an autoradiographic study.

    Science.gov (United States)

    Meneses, A; Manuel-Apolinar, L; Castillo, C; Castillo, E

    2007-03-12

    Traditionally, the search for memory circuits has been centered on examinations of amnesic and AD patients, cerebral lesions and, neuroimaging. A complementary alternative might be the use of autoradiography with radioligands. Indeed, ex vivo autoradiographic studies offer the advantage to detect functionally active receptors altered by pharmacological tools and memory formation. Hence, herein the 5-HT(6) receptor antagonist SB-399885 and the amnesic drugs scopolamine or dizocilpine were used to manipulate memory consolidation and 5-HT(6) receptors expression was determined by using [(3)H]-SB-258585. Thus, memory consolidation was impaired in scopolamine and dizocilpine treated groups relative to control vehicle but improved it in SB-399885-treated animals. SB-399885 improved memory consolidation seems to be associated with decreased 5-HT(6) receptors expression in 15 out 17 brain areas. Scopolamine or dizocilpine decreased 5-HT(6) receptors expression in nine different brain areas and increased it in CA3 hippocampus or other eight areas, respectively. In brain areas thought to be in charge of procedural memory such basal ganglia (i.e., nucleus accumbens, caudate putamen, and fundus striate) data showed that relative to control animals amnesic groups showed diminished (scopolamine) or augmented (dizocilpine) 5-HT(6) receptor expression. SB-399885 showing improved memory displayed an intermediate expression in these same brain regions. A similar intermediate expression occurs with regard to amygdala, septum, and some cortical areas in charge of explicit memory storage. However, relative to control group amnesic and SB-399885 rats in the hippocampus, region where explicit memory is formed, showed a complex 5-HT(6) receptors expression. In conclusion, these results indicate neural circuits underlying the effects of 5-HT(6) receptor antagonists in autoshaping task and offer some general clues about cognitive processes in general.

  10. Mechanisms of translation control underlying long-lasting synaptic plasticity and the consolidation of long-term memory.

    Science.gov (United States)

    Santini, Emanuela; Huynh, Thu N; Klann, Eric

    2014-01-01

    The complexity of memory formation and its persistence is a phenomenon that has been studied intensely for centuries. Memory exists in many forms and is stored in various brain regions. Generally speaking, memories are reorganized into broadly distributed cortical networks over time through systems level consolidation. At the cellular level, storage of information is believed to initially occur via altered synaptic strength by processes such as long-term potentiation. New protein synthesis is required for long-lasting synaptic plasticity as well as for the formation of long-term memory. The mammalian target of rapamycin complex 1 (mTORC1) is a critical regulator of cap-dependent protein synthesis and is required for numerous forms of long-lasting synaptic plasticity and long-term memory. As such, the study of mTORC1 and protein factors that control translation initiation and elongation has enhanced our understanding of how the process of protein synthesis is regulated during memory formation. Herein we discuss the molecular mechanisms that regulate protein synthesis as well as pharmacological and genetic manipulations that demonstrate the requirement for proper translational control in long-lasting synaptic plasticity and long-term memory formation. © 2014 Elsevier Inc. All rights reserved.

  11. Enhanced human memory consolidation with post-learning stress: interaction with the degree of arousal at encoding.

    Science.gov (United States)

    Cahill, Larry; Gorski, Lukasz; Le, Kathryn

    2003-01-01

    Abundant evidence indicates that endogenous stress hormones such as epinephrine and corticosterone modulate memory consolidation in animals. We recently provided the first demonstration that an endogenous stress hormone (epinephrine) can enhance human memory consolidation. However, these findings also suggested that post-learning stress hormone activation does not uniformly enhance memory for all recently acquired information; rather, that it interacts with the degree of arousal at initial encoding of material in modulating memory for the material. Here we tested this hypothesis by administering cold pressor stress (CPS) or a control procedure to subjects after they viewed slides of varying emotional content, and assessing memory for the slides 1 wk later. CPS, which significantly elevated salivary cortisol levels, enhanced memory for emotionally arousing slides compared with the controls, but did not affect memory for relatively neutral slides. These findings further support the view that post-learning stress hormone-related activity interacts with arousal at initial encoding to modulate memory consolidation.

  12. Effects of Propranolol, a β-noradrenergic Antagonist, on Memory Consolidation and Reconsolidation in Mice.

    Science.gov (United States)

    Villain, Hélène; Benkahoul, Aïcha; Drougard, Anne; Lafragette, Marie; Muzotte, Elodie; Pech, Stéphane; Bui, Eric; Brunet, Alain; Birmes, Philippe; Roullet, Pascal

    2016-01-01

    Memory reconsolidation impairment using the β-noradrenergic receptor blocker propranolol is a promising novel treatment avenue for patients suffering from pathogenic memories, such as post-traumatic stress disorder (PTSD). However, in order to better inform targeted treatment development, the effects of this compound on memory need to be better characterized via translational research. We examined the effects of systemic propranolol administration in mice undergoing a wide range of behavioral tests to determine more specifically which aspects of the memory consolidation and reconsolidation are impaired by propranolol. We found that propranolol (10 mg/kg) affected memory consolidation in non-aversive tasks (object recognition and object location) but not in moderately (Morris water maze (MWM) to highly (passive avoidance, conditioned taste aversion) aversive tasks. Further, propranolol impaired memory reconsolidation in the most and in the least aversive tasks, but not in the moderately aversive task, suggesting its amnesic effect was not related to task aversion. Moreover, in aquatic object recognition and location tasks in which animals were forced to behave (contrary to the classic versions of the tasks); propranolol did not impair memory reconsolidation. Taken together our results suggest that the memory impairment observed after propranolol administration may result from a modification of the emotional valence of the memory rather than a disruption of the contextual component of the memory trace. This is relevant to the use of propranolol to block memory reconsolidation in individuals with PTSD, as such a treatment would not erase the traumatic memory but only reduce the emotional valence associated with this event.

  13. Effects of propranolol, a β-noradrenergic antagonist, on memory consolidation and reconsolidation in mice

    Directory of Open Access Journals (Sweden)

    Hélène eVillain

    2016-03-01

    Full Text Available Memory reconsolidation impairment using the β-noradrenergic receptor blocker propranolol is a promising novel treatment avenue for patients suffering from pathogenic memories, such as post-traumatic stress disorder (PTSD. However, in order to better inform targeted treatment development, the effects of this compound on memory need to be better characterized via translational research. We examined the effects of systemic propranolol administration in mice undergoing a wide range of behavioral tests to determine more specifically which aspects of the memory consolidation and reconsolidation are impaired by propranolol. We found that propranolol (10mg/kg affected memory consolidation in non-aversive tasks (object recognition and object location but not in moderately (Morris water maze to highly (passive avoidance, conditioned taste aversion aversive tasks. Further, propranolol impaired memory reconsolidation in the most and in the least aversive tasks, but not in the moderately aversive task, suggesting its amnesic effect was not related to task aversion. Moreover, in aquatic object recognition and location tasks in which animals were forced to behave (contrary to the classic versions of the tasks; propranolol did not impair memory reconsolidation. Taken together our results suggest that the memory impairment observed after propranolol administration may result from a modification of the emotional valence of the memory rather than a disruption of the contextual component of the memory trace. This is relevant to the use of propranolol to block memory reconsolidation in individuals with PTSD, as such a treatment would not erase the traumatic memory but only reduce the emotional valence associated with this event.

  14. Effects of Exercise on Memory Consolidation and Retrieval of Passive Avoidance Learning In Young Male Rats

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    Saadati

    2010-09-01

    Full Text Available Purpose Previous studies have shown that physical activity improves learning and memory. Present study was performed to determine the effects of short term and long term treadmill exercise on learning, memory consolidation and retrieval of passive avoidance learning in an animal model. Methods In this study fifty male Wistar rats with 3-4 months of age were randomly divided into five groups (n=10 in each group. Control group was trained in passive avoidance box and was tested 10 min, 24 hr, 10 days and 3 months later. Two groups exercised on treadmill one hour at 17 m. min for 10 days and 3 months respectively and then were trained in passive avoidance box and were tested 10 min and 24 hr later. The other two groups were trained and were tested 10 days and 24 hr later and then exercised on treadmill as same as other exercised groups. Results Obtained results showed that short-term (10 days and long-term (3 months treadmill running before training by passive avoidance test had significant (P=0.006 and P=0.001 respectively effects on memory consolidation. However, no significant difference was observed between latency time of rats before and after exercise in exercised groups retrieval (P>0.05. Conclusion Our results showed that physical activity promoted learning and memory consolidation but it did not affect retrieval memory performance.

  15. Stress facilitates consolidation of verbal memory for a film but does not affect retrieval.

    Science.gov (United States)

    Beckner, Victoria E; Tucker, David M; Delville, Yvon; Mohr, David C

    2006-06-01

    The effect of psychosocial stress on distinct memory processes was investigated in 157 college students using a brief film, which enabled comparison of verbal and visual memory by using a single complex stimulus. Participants were stressed either following stimuli presentation (consolidation) or before testing 48 hr later (retrieval) and were compared with no-stress controls. Salivary cortisol was measured before and 20 min after stress. The consolidation group significantly outperformed controls on total and verbal film scores. Stress did not impair retrieval relative to controls. Exploratory analyses revealed a significant correlation between cortisol and verbal scores across all groups (r = .18). Results provide the first evidence of a facilitative effect of a stressor on verbal memory, but failed to replicate retrieval findings.

  16. Cooperative interaction between the basolateral amygdala and ventral tegmental area modulates the consolidation of inhibitory avoidance memory.

    Science.gov (United States)

    Nazari-Serenjeh, Farzaneh; Rezayof, Ameneh

    2013-01-10

    The aim of the current study was to examine the existence of a cooperative interaction between the basolateral nucleus of amygdala (BLA) and the ventral tegmental area (VTA) in inhibitory avoidance task. The BLA and the VTA regions of adult male Wistar rats were simultaneously cannulated and memory consolidation was measured in a step-through type inhibitory avoidance apparatus. Post-training microinjection of muscimol, a potent GABA-A receptor agonist (0.01-0.02 μg/rat), into the VTA impaired memory in a dose-dependent manner. Post-training intra-BLA microinjection of NMDA (0.02-0.04 μg/rat), 5 min before the intra-VTA injection of muscimol (0.02 μg/rat), attenuated muscimol-induced memory impairment. Microinjection of a NMDA receptor antagonist, D-AP5 (0.02-0.06 μg/rat) into the BLA inhibited NMDA effect on the memory impairment induced by intra-VTA microinjection of muscimol. On the other hand, post-training intra-BLA microinjection of muscimol (0.02-0.04 μg/rat) dose-dependently decreased step-through latency, indicating an impairing effect on memory. This impairing effect was however significantly attenuated by intra-VTA microinjection of NMDA (0.01-0.03 μg/rat). Intra-VTA microinjection of D-AP5 (0.02-0.08 μg/rat), 5 min prior to NMDA injection, inhibited NMDA response on the impairing effect induced by intra-BLA microinjection of muscimol. It should be considered that post-training microinjection of the same doses of NMDA or D-AP5 into the BLA or the VTA alone had no effect on memory consolidation. The data suggest that the relationship between the BLA and the VTA in mediating memory consolidation in inhibitory avoidance learning may be dependent on a cooperative interaction between the glutamatergic and GABAergic systems via NMDA and GABA-A receptors.

  17. The Influence of Sleep on the Consolidation of Positive Emotional Memories: Preliminary Evidence

    Directory of Open Access Journals (Sweden)

    Alexis M. Chambers

    2014-05-01

    Full Text Available Studies have not only shown that a period of sleep following learning offers greater benefits to later memory than a period of wakefulness, but also that sleep actively promotes those components of memories that are emotionally salient. However, sleep's role in emotional memory consolidation has largely been investigated with memories that are specifically negative in content, such as memory for negative images or texts, leaving open the question of whether sleep influences positive memories in a similar manner. The current study investigated the emotional memory trade-off effect for positive versus neutral information. Scenes in which a positive or neutral object was placed on a neutral background were encoded prior to a period of polysomnographically-monitored nocturnal sleep or daytime wakefulness. Recognition memory was tested for the objects and backgrounds separately following the delay using the Remember/Know paradigm. Compared to wake participants, those who slept during the delay had increased recollection memory performance for positive objects, but not the neutral components of the studied scenes. Further, familiarity of positive objects was negatively correlated with REM latency. These results provide preliminary evidence that sleep contributes to the selective processing of positive memories, and point toward a role for REM sleep in positive memory formation.

  18. The cannabinoid system in the retrosplenial cortex modulates fear memory consolidation, reconsolidation, and extinction

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Crestani, Ana Paula; Quillfeldt, Jorge Alberto; Mello e Souza, Tadeu

    2015-01-01

    Despite the fact that the cannabinoid receptor type 1 (CB1R) plays a pivotal role in emotional memory processing in different regions of the brain, its function in the retrosplenial cortex (RSC) remains unknown. Here, using contextual fear conditioning in rats, we showed that a post-training intra-RSC infusion of the CB1R antagonist AM251 impaired, and the agonist CP55940 improved, long-term memory consolidation. Additionally, a post-reactivation infusion of AM251 enhanced memory reconsolidation, while CP55940 had the opposite effect. Finally, AM251 blocked extinction, whereas CP55940 facilitated it and maintained memory extinguished over time. Altogether, our data strongly suggest that the cannabinoid system of the RSC modulates emotional memory. PMID:26572648

  19. 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.

  20. Parvalbumin-expressing interneurons coordinate hippocampal network dynamics required for memory consolidation

    Science.gov (United States)

    Ognjanovski, Nicolette; Schaeffer, Samantha; Wu, Jiaxing; Mofakham, Sima; Maruyama, Daniel; Zochowski, Michal; Aton, Sara J.

    2017-04-01

    Activity in hippocampal area CA1 is essential for consolidating episodic memories, but it is unclear how CA1 activity patterns drive memory formation. We find that in the hours following single-trial contextual fear conditioning (CFC), fast-spiking interneurons (which typically express parvalbumin (PV)) show greater firing coherence with CA1 network oscillations. Post-CFC inhibition of PV+ interneurons blocks fear memory consolidation. This effect is associated with loss of two network changes associated with normal consolidation: (1) augmented sleep-associated delta (0.5-4 Hz), theta (4-12 Hz) and ripple (150-250 Hz) oscillations; and (2) stabilization of CA1 neurons' functional connectivity patterns. Rhythmic activation of PV+ interneurons increases CA1 network coherence and leads to a sustained increase in the strength and stability of functional connections between neurons. Our results suggest that immediately following learning, PV+ interneurons drive CA1 oscillations and reactivation of CA1 ensembles, which directly promotes network plasticity and long-term memory formation.

  1. The impact of progesterone on memory consolidation of threatening images in women.

    Science.gov (United States)

    Felmingham, Kim L; Fong, Wing Chee; Bryant, Richard A

    2012-11-01

    Recent findings suggest that consolidation of emotional memories is influenced by menstrual phase in women. In contrast to other phases, in the mid-luteal phase when progesterone levels are elevated, cortisol levels are increased and correlated with emotional memory. This study examined the impact of progesterone on cortisol and memory consolidation of threatening stimuli under stressful conditions. Thirty women were recruited for the high progesterone group (in the mid-luteal phase) and 26 for the low progesterone group (in non-luteal phases of the menstrual cycle). Women were shown a series of 20 neutral or threatening images followed immediately by either a stressor (cold pressor task) or control condition. Participants returned two days later for a surprise free recall test of the images and salivary cortisol responses were monitored. High progesterone levels were associated with higher baseline and stress-evoked cortisol levels, and enhanced memory of negative images when stress was received. A positive correlation was found between stress-induced cortisol levels and memory recall of threatening images. These findings suggest that progesterone mediates cortisol responses to stress and subsequently predicts memory recall for emotionally arousing stimuli.

  2. Nap and melatonin-induced changes in hippocampal activation and their role in verbal memory consolidation.

    Science.gov (United States)

    Gorfine, Tali; Yeshurun, Yaara; Zisapel, Nava

    2007-11-01

    Overnight sleep contributes to memory consolidation; even a short nap improves memory performance. Such improvement has been linked to hippocampal activity during sleep. Melatonin has been shown to affect the human hippocampus and to induce 'sleep like' changes in brain activation. We therefore conducted and compared two functional magnetic resonance imaging studies: the first study assessed the effect of a 2-hr mid-day nap versus an equal amount of wakefulness on a verbal memory task (unrelated word pair association); the second assessed the effect of melatonin versus placebo (both conditions without nap) on a similar task. We report that following a nap relative to wakefulness, successful retrieval-related activation in the parahippocampus is decreased. A smaller decrease is seen in wakefulness with melatonin but not placebo. In parallel, an improvement in verbal memory recall was found after a nap compared with wakefulness but not with melatonin during wakefulness compared with placebo. Our findings demonstrate effects of melatonin that resemble those of sleep on verbal memory processing in the hippocampus thus suggesting that melatonin, like sleep, can initiate offline plastic changes underlying memory consolidation; they also suggest that concomitant rest without interferences is necessary for enhanced performance.

  3. Acute Exercise and Motor Memory Consolidation: The Role of Exercise Timing.

    Science.gov (United States)

    Thomas, Richard; Beck, Mikkel Malling; Lind, Rune Rasmussen; Korsgaard Johnsen, Line; Geertsen, Svend Sparre; Christiansen, Lasse; Ritz, Christian; Roig, Marc; Lundbye-Jensen, Jesper

    2016-01-01

    High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs), healthy male subjects randomly assigned to one of four groups either performing a high intensity (90% Maximal Power Output) exercise bout at 20 min (EX90), 1 h (EX90+1), 2 h (EX90+2) after acquisition or rested (CON). Retention tests were performed at 1 d (R1) and 7 d (R7). At R1 changes in performance scores after acquisition were greater for EX90 than CON (p Exercise-induced improvements in procedural memory diminish as the temporal proximity of exercise from acquisition is increased. Timing of exercise following motor practice is important for motor memory consolidation.

  4. The effect of sub-anesthetic and anesthetic ketamine on water maze memory acquisition, consolidation and retrieval.

    Science.gov (United States)

    Moosavi, Maryam; Yadollahi Khales, Golnaz; Rastegar, Karim; Zarifkar, Asadollah

    2012-02-29

    Ketamine, a non-selective inhibitor of NMDA (N-methyl-D-aspartate) channels is used in anesthetic or sub-anesthetic doses to induce analgesia, amnesia, to suppress fear, anxiety and depression. Although the ketamine's effect on memory acquisition is known, its effects on other aspects of memory are controversial. Morris water maze is a task which assesses spatial learning and memory. This study was aimed to assess the ketamine's differential effect on water maze memory acquisition, consolidation and retrieval. Male Sprague-Dawley rats (250-350 g) were trained in water maze single training session. 24h later a probe trial which was consisted of a single trial without platform was done. To assess the effect of ketamine on water maze memory acquisition it was administered before training; to assess its effect on memory consolidation it was administered immediately after training and to assess its effect on memory retrieval it was injected before probe trial. Ketamine both in sub-anesthetic and anesthetic doses impaired water maze memory acquisition, its anesthetic dose but not sub-anesthetic dose impaired memory consolidation and on retrieval stage, both doses deteriorated memory retrieval. It seems that NMDA receptor activity is not just necessary during water maze memory acquisition but also their post-learning reactivation is required to maintain memory consolidation and retrieval.

  5. Calcineurin phosphatase as a negative regulator of fear memory in hippocampus: control on nuclear factor-κB signaling in consolidation and reconsolidation.

    Science.gov (United States)

    de la Fuente, Verónica; Federman, Noel; Fustiñana, María Sol; Zalcman, Gisela; Romano, Arturo

    2014-12-01

    Protein phosphatases are important regulators of neural plasticity and memory. Some studies support that the Ca(2+) /calmodulin-dependent phosphatase calcineurin (CaN) is, on the one hand, a negative regulator of memory formation and, on the other hand, a positive regulator of memory extinction and reversal learning. However, the signaling mechanisms by which CaN exerts its action in such processes are not well understood. Previous findings support that CaN negatively regulate the nuclear factor kappaB (NF-κB) signaling pathway during extinction. Here, we have studied the role of CaN in contextual fear memory consolidation and reconsolidation in the hippocampus. We investigated the CaN control on the NF-κB signaling pathway, a key mechanism that regulates gene expression in memory processes. We found that post-training intrahippocampal administration of the CaN inhibitor FK506 enhanced memory retention one day but not two weeks after training. Accordingly, the inhibition of CaN by FK506 increased NF-κB activity in dorsal hippocampus. The administration of the NF-κB signaling pathway inhibitor sulfasalazine (SSZ) impeded the enhancing effect of FK506. In line with our findings in consolidation, FK506 administration before memory reactivation enhanced memory reconsolidation when tested one day after re-exposure to the training context. Strikingly, memory was also enhanced two weeks after training, suggesting that reinforcement during reconsolidation is more persistent than during consolidation. The coadministration of SSZ and FK506 blocked the enhancement effect in reconsolidation, suggesting that this facilitation is also dependent on the NF-κB signaling pathway. In summary, our results support a novel mechanism by which memory formation and reprocessing can be controlled by CaN regulation on NF-κB activity. © 2014 Wiley Periodicals, Inc.

  6. Real-world-time simulation of memory consolidation in a large-scale cerebellar model

    Directory of Open Access Journals (Sweden)

    Masato eGosui

    2016-03-01

    Full Text Available We report development of a large-scale spiking network model of thecerebellum composed of more than 1 million neurons. The model isimplemented on graphics processing units (GPUs, which are dedicatedhardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation ofcerebellar activity for 1 sec completes within 1 sec in thereal-world time, with temporal resolution of 1 msec.This allows us to carry out a very long-term computer simulationof cerebellar activity in a practical time with millisecond temporalresolution. Using the model, we carry out computer simulationof long-term gain adaptation of optokinetic response (OKR eye movementsfor 5 days aimed to study the neural mechanisms of posttraining memoryconsolidation. The simulation results are consistent with animal experimentsand our theory of posttraining memory consolidation. These resultssuggest that realtime computing provides a useful means to studya very slow neural process such as memory consolidation in the brain.

  7. Enhanced Noradrenergic Activity Potentiates Fear Memory Consolidation and Reconsolidation by Differentially Recruiting alpha1- and beta-Adrenergic Receptors

    Science.gov (United States)

    Gazarini, Lucas; Stern, Cristina A. Jark; Carobrez, Antonio P.; Bertoglio, Leandro J.

    2013-01-01

    Consolidation and reconsolidation are phases of memory stabilization that diverge slightly. Noradrenaline is known to influence both processes, but the relative contribution of alpha1- and beta-adrenoceptors is unclear. The present study sought to investigate this matter by comparing their recruitment to consolidate and/or reconsolidate a…

  8. Intracerebellar vermis histamine facilitates memory consolidation in the elevated T maze model.

    Science.gov (United States)

    Silva-Marques, Bruna; Gianlorenço, Anna Carolyna Lepesteur; Mattioli, Rosana

    2016-05-01

    Experimental evidence suggests that the cerebellum plays a more complex role in learning than simply regulating the motor response. Rather, it is thought to play a significant role in the consolidation of emotional memory in mice. Due to the difficulty of interpreting fear and anxiety behaviors-the standard methodology for the study of the histaminergic system and emotional memory-in mice, we propose a behavioral assessment of mice subjected to the Elevated T-maze after histamine microinjection of the cerebellar vermis. Young male Swiss albino mice weighing 25-35g were used. In addition, locomotor activity was tested in an open field test. Our data suggest that histamine did not affect memory consolidation during escape or open field behavior at the doses used in this study. However, we observed a significant increase in inhibitory avoidance on the second day in animals receiving a dose of 6.8nmol/0.5μl, suggesting that histamine facilitates the consolidation of inhibitory avoidance in mice.

  9. Real-World-Time Simulation of Memory Consolidation in a Large-Scale Cerebellar Model.

    Science.gov (United States)

    Gosui, Masato; Yamazaki, Tadashi

    2016-01-01

    We report development of a large-scale spiking network model of the cerebellum composed of more than 1 million neurons. The model is implemented on graphics processing units (GPUs), which are dedicated hardware for parallel computing. Using 4 GPUs simultaneously, we achieve realtime simulation, in which computer simulation of cerebellar activity for 1 s completes within 1 s in the real-world time, with temporal resolution of 1 ms. This allows us to carry out a very long-term computer simulation of cerebellar activity in a practical time with millisecond temporal resolution. Using the model, we carry out computer simulation of long-term gain adaptation of optokinetic response (OKR) eye movements for 5 days aimed to study the neural mechanisms of posttraining memory consolidation. The simulation results are consistent with animal experiments and our theory of posttraining memory consolidation. These results suggest that realtime computing provides a useful means to study a very slow neural process such as memory consolidation in the brain.

  10. The Effect of Acute Exercise on Consolidation and Retention of Motor Memory

    DEFF Research Database (Denmark)

    Skriver, Kasper Christen

    2014-01-01

    as effectively as running. Our research suggests that norepinephrine, lactate and brain-derived neurotrophic factor might be involved in mediating the effect of exercise on motor memory. Overall, the results imply that exercise can be applied to facilitate long-term retention of motor memory.......There is substantial evidence that a single bout of exercise can improve cognitive functions and retention of certain types of declarative memory. However, it is unclear if a similar effect can be demonstrated when coupling physical activity with the acquisition and retention of a motor skill....... Additionally, POST outperformed PRE after seven days, thus indicating that exercise affects the process during which the memory is consolidated more than learning itself. In order to investigate if the behavioral effects of exercise could be demonstrated in school children, we conducted Study II, partially...

  11. A role for nitric oxide-driven retrograde signaling in the consolidation of a fear memory

    Directory of Open Access Journals (Sweden)

    Kathie A Overeem

    2010-02-01

    Full Text Available In both invertebrate and vertebrate models of synaptic plasticity, signaling via the putative “retrograde messenger” nitric oxide (NO has been hypothesized to serve as a critical link between functional and structural alterations at pre- and postsynaptic sites. However, while in vitro models of synaptic plasticity have consistently implicated NO signaling in linking postsynaptic induction mechanisms with accompanying presynaptic changes, a convincing role of such “retrograde signaling” in mammalian memory formation has remained elusive. Using auditory Pavlovian fear conditioning, we show that synaptic plasticity and NO signaling in the lateral nucleus of the amygdala (LA regulate the expression of the ERK-driven immediate early gene early growth response gene I (EGR-1 in regions of the auditory thalamus that are presynaptic to the LA. Further, antisense knockdown of EGR-1 in the auditory thalamus impairs both fear memory consolidation and the training-induced elevation of two presynaptically localized proteins in the LA. These findings indicate that synaptic plasticity and NO signaling in the LA during auditory fear conditioning promote alterations in ERK-driven gene expression in auditory thalamic neurons that are required for both fear memory consolidation as well as presynaptic correlates of fear memory formation in the LA, and provide general support for a role of NO as a “retrograde signal” in mammalian memory formation.

  12. The central role of heat shock factor 1 in synaptic fidelity and memory consolidation.

    Science.gov (United States)

    Hooper, Philip L; Durham, Heather D; Török, Zsolt; Hooper, Paul L; Crul, Tim; Vígh, László

    2016-09-01

    Networks of neuronal synapses are the fundamental basis for making and retaining memory. Reduced synapse number and quality correlates with loss of memory in dementia. Heat shock factor 1 (HSF1), the major transcription factor regulating expression of heat shock genes, plays a central role in proteostasis, in establishing and sustaining synaptic fidelity and function, and in memory consolidation. Support for this thesis is based on these observations: (1) heat shock induces improvements in synapse integrity and memory consolidation; (2) synaptic depolarization activates HSF1; (3) activation of HSF1 alone (independent of the canonical heat shock response) augments formation of essential synaptic elements-neuroligands, vesicle transport, synaptic scaffolding proteins, lipid rafts, synaptic spines, and axodendritic synapses; (4) HSF1 coalesces and activates memory receptors in the post-synaptic dendritic spine; (5) huntingtin or α-synuclein accumulation lowers HSF1 while HSF1 lowers huntingtin and α-synuclein aggregation-a potential vicious cycle; and (6) HSF1 agonists (including physical activity) can improve cognitive function in dementia models. Thus, via direct gene expression of synaptic elements, production of HSPs that assure high protein fidelity, and activation of other neuroprotective signaling pathways, HSF1 agonists could provide breakthrough therapy for dementia-associated disease.

  13. The effects of non-contingent extrinsic and intrinsic rewards on memory consolidation.

    Science.gov (United States)

    Nielson, Kristy A; Bryant, Ted

    2005-07-01

    Emotional and arousing treatments given shortly after learning enhance delayed memory retrieval in animal and human studies. Positive affect and reward induced prior to a variety of cognitive tasks enhance performance, but their ability to affect memory consolidation has not been investigated before. Therefore, we investigated the effects of a small, non-contingent, intrinsic or extrinsic reward on delayed memory retrieval. Participants (n=108) studied and recalled a list of 30 affectively neutral, imageable nouns. Experimental groups were then given either an intrinsic reward (e.g., praise) or an extrinsic reward (e.g., US 1 dollar). After a one-week delay, participants' retrieval performance for the word list was significantly better in the extrinsic reward groups, whether the reward was expected or not, than in controls. Those who received the intrinsic reward performed somewhat better than controls, but the difference was not significant. Thus, at least some forms of arousal and reward, even when semantically unrelated to the learned material, can effectively modulate memory consolidation. These types of treatments might be useful for the development of new memory intervention strategies.

  14. Relaxing music counters heightened consolidation of emotional memory.

    Science.gov (United States)

    Rickard, Nikki S; Wong, Wendy Wing; Velik, Lauren

    2012-02-01

    Emotional events tend to be retained more strongly than other everyday occurrences, a phenomenon partially regulated by the neuromodulatory effects of arousal. Two experiments demonstrated the use of relaxing music as a means of reducing arousal levels, thereby challenging heightened long-term recall of an emotional story. In Experiment 1, participants (N=84) viewed a slideshow, during which they listened to either an emotional or neutral narration, and were exposed to relaxing or no music. Retention was tested 1 week later via a forced choice recognition test. Retention for both the emotional content (Phase 2 of the story) and material presented immediately after the emotional content (Phase 3) was enhanced, when compared with retention for the neutral story. Relaxing music prevented the enhancement for material presented after the emotional content (Phase 3). Experiment 2 (N=159) provided further support to the neuromodulatory effect of music by post-event presentation of both relaxing music and non-relaxing auditory stimuli (arousing music/background sound). Free recall of the story was assessed immediately afterwards and 1 week later. Relaxing music significantly reduced recall of the emotional story (Phase 2). The findings provide further insight into the capacity of relaxing music to attenuate the strength of emotional memory, offering support for the therapeutic use of music for such purposes.

  15. Effects of stress and corticosterone in two post-training periods, on spatial memory consolidation in adult male Wistar rats.

    Directory of Open Access Journals (Sweden)

    Jeimmy Marcela Cerón

    2015-04-01

    Full Text Available Memory consolidation is the process of gradual stabilization of long-term memory after learning (Alberini & Taubenfeld, 2008. This process involves the activation of intracellular signaling cascades that lead to the reorganization of synaptic proteins. Activation of these signaling pathways can regulate gene expression and protein synthesis (Brivanlou & Darnell, 2002. It is considered that the new proteins synthesized after learning are responsible for the changes in the neural architecture associated with memory consolidation (Mileusnic, 2004. In this sense, it has been shown that consolidation may be interrupted by inhibiting protein synthesis, leading to forgetfulness of the experience (Meeter & Murre, 2004. Although the dominant hypothesis is that memory consolidation requires a single molecular cascade, it has been suggested that multiple sets of synaptic modifications are required to reinforce changes after memory acquisition (Wittenber & Tsien, 2002. Consistently, recent studies have shown that protein synthesis associated with memory consolidation occurs in at least two post-training periods: immediately and 3-6 hours after training (Igaz et al., 2002; Bekinschtein et al., 2007. These memory consolidation periods share some molecular phenomena; however, each period is also associated with events that are different from the other (Igaz et al., 2002. To date, there is a substantial amount of evidence showing that stressful events may facilitate neuronal function and cognition. The term "stress" usually refers to a nonspecific response of the body to stimuli that threaten the physiological/psychological homeostasis (Selye, 1976; Chrousos et al., 1988. The stress response is associated with the activation of two physiological systems: the hypothalamic-pituitary-adrenal (HPA axis and the sympathetic adrenomedullary (SAM. Glucocorticoids (cortisol in humans and corticosterone in rodents are steroid hormones secreted by the adrenal glands as a

  16. 3D contaminant migration model with consolidation dependent transport coefficients

    Institute of Scientific and Technical Information of China (English)

    Lu Huang; Cheng-Gang Zhao; Yan Liu; Guo-Qing Cai

    2012-01-01

    Soil consolidation would induce variations of its transport coefficients such as hydraulic conductivity and diffusion coefficient. This paper presents a study of the influence of barrier consolidation on transport coefficients,and a 3D transport model based on mixture theory is proposed for describing the liners that involve circular defects in the geomembrane.The elastoplastic ALPHA model is revised by using the spatially mobilized plane (SMP) criterion for simulating the deformation of the soils.Then,the 3D model coupling the nonlinear consolidation and contaminant advection-diffusion is solved using the finite element software ABAQUS.The results show that the importance of reducing the defect size in the geomembrane and the liner porosity to control the contaminant concentration increase.

  17. Behavioural pharmacology and its contribution to the molecular basis of memory consolidation.

    Science.gov (United States)

    Izquierdo, I; McGaugh, J L

    2000-11-01

    Recent findings have significantly advanced our understanding the mechanisms of memory formation. Most of these advances stemmed from behavioural pharmacology research involving, particularly, the localized infusion of drugs with specific molecular actions into specific brain regions. This approach has revealed brain structures involved in different memory types and the main neurotransmitter systems and sequence of metabolic cascades that participate in memory consolidation. Biochemical studies and, in several cases, studies of genetically manipulated animals, in which receptors or enzymes affected by the various drugs were absent or overexpressed, have complemented the pharmacological research. Although most studies have concentrated on the involvement of the hippocampus, many have also investigated the entorhinal cortex, other regions of the cortex, and the amygdala. Behavioural pharmacology has been of crucial importance in establishing the major neurohumoral and hormonal systems involved in the modulation of memory formation. These systems act on specific steps of memory formation in the hippocampus and in the entorhinal, parietal, and cingulate cortex. A specialized system mediated by the basolateral amygdaloid nucleus, and involving several neuromodulatory systems, is activated by emotional arousal and serves to regulate memory formation in other brain regions. The core mechanisms involved in the formation of explicit (declarative) memory are in many respects similar to those of long-term potentiation (LTP), particularly in the hippocampus. However, there are also important differences between memory formation and LTP. Memory formation involves numerous modulatory influences, the co-participation of various brain regions other than the hippocampus, and some properties that are specific to memory and absent in LTP (i.e. flexibility of response). We discuss the implications of these similarities and differences for understanding the neural bases of memory.

  18. Consolidation of Prospective Memory: Effects of Sleep on Completed and Reinstated Intentions

    Science.gov (United States)

    Barner, Christine; Seibold, Mitja; Born, Jan; Diekelmann, Susanne

    2017-01-01

    Sleep has been shown to facilitate the consolidation of prospective memory, which is the ability to execute intended actions at the appropriate time in the future. In a previous study, the sleep benefit for prospective memory was mainly expressed as a preservation of prospective memory performance under divided attention as compared to full attention. Based on evidence that intentions are only remembered as long as they have not been executed yet (cf. ‘Zeigarnik effect’), here we asked whether the enhancement of prospective memory by sleep vanishes if the intention is completed before sleep and whether completed intentions can be reinstated to benefit from sleep again. In Experiment 1, subjects learned cue-associate word pairs in the evening and were prospectively instructed to detect the cue words and to type in the associates in a lexical decision task (serving as ongoing task) 2 h later before a night of sleep or wakefulness. At a second surprise test 2 days later, sleep and wake subjects did not differ in prospective memory performance. Specifically, both sleep and wake groups detected fewer cue words under divided compared to full attention, indicating that sleep does not facilitate the consolidation of completed intentions. Unexpectedly, in Experiment 2, reinstating the intention, by instructing subjects about the second test after completion of the first test, was not sufficient to restore the sleep benefit. However, in Experiment 3, where subjects were instructed about both test sessions immediately after learning, sleep facilitated prospective memory performance at the second test after 2 days, evidenced by comparable cue word detection under divided attention and full attention in sleep participants, whereas wake participants detected fewer cue words under divided relative to full attention. Together, these findings show that for prospective memory to benefit from sleep, (i) the intention has to be active across the sleep period, and (ii) the

  19. Changes in corticospinal excitability during consolidation predict acute exercise-induced off-line gains in procedural memory

    DEFF Research Database (Denmark)

    Ostadan, Fatemeh; Centeno, Carla; Daloze, Jean-Felix

    2016-01-01

    A single bout of cardiovascular exercise performed immediately after practicing a motor task improves the long-term retention of the skill through an optimization of memory consolidation. However, the specific brain mechanisms underlying the effects of acute cardiovascular exercise on procedural...... in the exercise condition showed larger (∼24%) improvements in procedural memory through consolidation although differences between groups did not reach statistical significance. Exercise promoted an increase in CSE, which remained elevated 2h after exercise. More importantly, global increases in CSE following...... memory are poorly understood. We sought to determine if a single bout of exercise modifies corticospinal excitability (CSE) during the early stages of memory consolidation. In addition, we investigated if changes in CSE are associated with exercise-induced off-line gains in procedural memory...

  20. Rapid eye movement sleep deprivation disrupts consolidation but not reconsolidation of novel object recognition memory in rats.

    Science.gov (United States)

    Chen, Lin; Tian, Shaowen; Ke, Jie

    2014-03-20

    There is increasing evidence that sleep plays a critical role in memory consolidation. However, there are comparatively few studies that have assessed the relationship between sleep and memory reconsolidation. In the present study, we explored the effects of rapid eye movement sleep deprivation (RSD) on the consolidation (experiment 1) and reconsolidation (experiment 2) of novel object recognition memory in rats. In experiment 1 behavioral procedure involved two training phases: sample and test. Rats were subjected to 6h RSD starting either immediately after sample (exposed to 2 objects) or 6h later. In experiment 2 behavioral procedure involved three training phases: sample, reactivation and test. Rats were subjected to 6h RSD starting either immediately after reactivation (exposed to the same 2 sample objects to reactivate the memory trace) or 6h later. Results from experiment 1 showed that post-sample RSD from 0 to 6h but not 6 to 12h disrupted novel object recognition memory consolidation. However, we found that post-reactivation RSD whether from 0 to 6h or 6 to 12h had no effect on novel object recognition memory reconsolidation in experiment 2. The results indicated that RSD selectively disrupted consolidation of novel object recognition memory, suggesting a dissociation effect of RSD on consolidation and reconsolidation.

  1. 5-HT1A receptor blockade targeting the basolateral amygdala improved stress-induced impairment of memory consolidation and retrieval in rats.

    Science.gov (United States)

    Sardari, M; Rezayof, A; Zarrindast, M-R

    2015-08-06

    The aim of the present study was to investigate the possible role of basolateral amygdala (BLA) 5-HT1A receptors in memory formation under stress. We also examined whether the blockade of these receptors is involved in stress-induced state-dependent memory. Adult male Wistar rats received cannula implants that bilaterally targeted the BLA. Long-term memory was examined using the step-through type of passive avoidance task. Behavioral stress was evoked by exposure to an elevated platform (EP) for 10, 20 and 30min. Post-training exposure to acute stress (30min) impaired the memory consolidation. In addition, pre-test exposure to acute stress-(20 and 30min) induced the impairment of memory retrieval. Interestingly, the memory impairment induced by post-training exposure to stress was restored in the animals that received 20- or 30-min pre-test stress exposure, suggesting stress-induced state-dependent memory retrieval. Post-training BLA-targeted injection of a selective 5-HT1A receptor antagonist, (S)-WAY-100135 (2μg/rat), prevented the impairing effect of stress on memory consolidation. Pre-test injection of the same doses of (S)-WAY-100135 that was targeted to the BLA also reversed stress-induced memory retrieval impairment. It should be considered that post-training or pre-test BLA-targeted injection of (S)-WAY-100135 (0.5-2μg/rat) by itself had no effect on the memory formation. Moreover, pre-test injection of (S)-WAY-100135 (2μg/rat) that targeted the BLA inhibited the stress-induced state-dependent memory retrieval. Taken together, our findings suggest that post-training or pre-test exposure to acute stress induced the impairment of memory consolidation, retrieval and state-dependent learning. The BLA 5-HT1A receptors have a critical role in learning and memory under stress. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  2. Assessing the Effect of Early Visual Cortex Transcranial Magnetic Stimulation on Working Memory Consolidation.

    Science.gov (United States)

    van Lamsweerde, Amanda E; Johnson, Jeffrey S

    2017-07-01

    Maintaining visual working memory (VWM) representations recruits a network of brain regions, including the frontal, posterior parietal, and occipital cortices; however, it is unclear to what extent the occipital cortex is engaged in VWM after sensory encoding is completed. Noninvasive brain stimulation data show that stimulation of this region can affect working memory (WM) during the early consolidation time period, but it remains unclear whether it does so by influencing the number of items that are stored or their precision. In this study, we investigated whether single-pulse transcranial magnetic stimulation (spTMS) to the occipital cortex during VWM consolidation affects the quantity or quality of VWM representations. In three experiments, we disrupted VWM consolidation with either a visual mask or spTMS to retinotopic early visual cortex. We found robust masking effects on the quantity of VWM representations up to 200 msec poststimulus offset and smaller, more variable effects on WM quality. Similarly, spTMS decreased the quantity of VWM representations, but only when it was applied immediately following stimulus offset. Like visual masks, spTMS also produced small and variable effects on WM precision. The disruptive effects of both masks and TMS were greatly reduced or entirely absent within 200 msec of stimulus offset. However, there was a reduction in swap rate across all time intervals, which may indicate a sustained role of the early visual cortex in maintaining spatial information.

  3. Effect of positive emotion on consolidation of memory for faces: the modulation of facial valence and facial gender.

    Science.gov (United States)

    Wang, Bo

    2013-01-01

    Studies have shown that emotion elicited after learning enhances memory consolidation. However, no prior studies have used facial photos as stimuli. This study examined the effect of post-learning positive emotion on consolidation of memory for faces. During the learning participants viewed neutral, positive, or negative faces. Then they were assigned to a condition in which they either watched a 9-minute positive video clip, or a 9-minute neutral video. Then 30 minutes after the learning participants took a surprise memory test, in which they made "remember", "know", and "new" judgements. The findings are: (1) Positive emotion enhanced consolidation of recognition for negative male faces, but impaired consolidation of recognition for negative female faces; (2) For males, recognition for negative faces was equivalent to that for positive faces; for females, recognition for negative faces was better than that for positive faces. Our study provides the important evidence that effect of post-learning emotion on memory consolidation can extend to facial stimuli and such an effect can be modulated by facial valence and facial gender. The findings may shed light on establishing models concerning the influence of emotion on memory consolidation.

  4. The effect of selective REM-sleep deprivation on the consolidation and affective evaluation of emotional memories.

    Science.gov (United States)

    Wiesner, Christian D; Pulst, Julika; Krause, Fanny; Elsner, Marike; Baving, Lioba; Pedersen, Anya; Prehn-Kristensen, Alexander; Göder, Robert

    2015-07-01

    Emotion boosts the consolidation of events in the declarative memory system. Rapid eye movement (REM) sleep is believed to foster the memory consolidation of emotional events. On the other hand, REM sleep is assumed to reduce the emotional tone of the memory. Here, we investigated the effect of selective REM-sleep deprivation, SWS deprivation, or wake on the affective evaluation and consolidation of emotional and neutral pictures. Prior to an 9-h retention interval, sixty-two healthy participants (23.5 ± 2.5 years, 32 female, 30 male) learned and rated their affect to 80 neutral and 80 emotionally negative pictures. Despite rigorous deprivation of REM sleep or SWS, the residual sleep fostered the consolidation of neutral and negative pictures. Furthermore, emotional arousal helped to memorize the pictures. The better consolidation of negative pictures compared to neutral ones was most pronounced in the SWS-deprived group where a normal amount of REM sleep was present. This emotional memory bias correlated with REM sleep only in the SWS-deprived group. Furthermore, emotional arousal to the pictures decreased over time, but neither sleep nor wake had any differential effect. Neither the comparison of the affective ratings (arousal, valence) during encoding and recognition, nor the affective ratings of the recognized targets and rejected distractors supported the hypothesis that REM sleep dampens the emotional reaction to remembered stimuli. The data suggest that REM sleep fosters the consolidation of emotional memories but has no effect on the affective evaluation of the remembered contents.

  5. 8-OH-DPAT facilitated memory consolidation and increased hippocampal and cortical cAMP production.

    Science.gov (United States)

    Manuel-Apolinar, L; Meneses, A

    2004-01-05

    Animals were submitted to an associative learning task named Pavlovian/instrumental autoshaping (P/I-A) and treated with selective 5-HT1A and 5-HT7 receptor agonists and antagonists. Next, they were sacrificed, their brains removed, dissected and changes on cortical and hippocampal cyclic adenosine monophosphate (cAMP) production were determined. Results revealed that, the 8-OH-DPAT treatment facilitated memory consolidation of autoshaping and that effect was blocked completely by WAY100635 and partially by DR4004. WAY100635 or DR4004 alone had no effect on autoshaping. The cAMP results were complex and yielded no clear relationship to the memory results. Thus, cortical and hippocampal increased on cAMP production was observed following administration of the 5-HT(1A/7) agonist 8-OH-DPAT. The memory effect was, completely or partially, reversed by the selective antagonists WAY100635 (5-HT1A) or DR4004 (5-HT7), respectively.

  6. Acute Exercise and Motor Memory Consolidation: The Role of Exercise Timing

    Directory of Open Access Journals (Sweden)

    Richard Thomas

    2016-01-01

    Full Text Available High intensity aerobic exercise amplifies offline gains in procedural memory acquired during motor practice. This effect seems to be evident when exercise is placed immediately after acquisition, during the first stages of memory consolidation, but the importance of temporal proximity of the exercise bout used to stimulate improvements in procedural memory is unknown. The effects of three different temporal placements of high intensity exercise were investigated following visuomotor skill acquisition on the retention of motor memory in 48 young (24.0 ± 2.5 yrs, healthy male subjects randomly assigned to one of four groups either performing a high intensity (90% Maximal Power Output exercise bout at 20 min (EX90, 1 h (EX90+1, 2 h (EX90+2 after acquisition or rested (CON. Retention tests were performed at 1 d (R1 and 7 d (R7. At R1 changes in performance scores after acquisition were greater for EX90 than CON (p<0.001 and EX90+2 (p=0.001. At R7 changes in performance scores for EX90, EX90+1, and EX90+2 were higher than CON (p<0.001, p=0.008, and p=0.008, resp.. Changes for EX90 at R7 were greater than EX90+2 (p=0.049. Exercise-induced improvements in procedural memory diminish as the temporal proximity of exercise from acquisition is increased. Timing of exercise following motor practice is important for motor memory consolidation.

  7. Differences between Presentation Methods in Working Memory Procedures: A Matter of Working Memory Consolidation

    Science.gov (United States)

    Ricker, Timothy J.; Cowan, Nelson

    2014-01-01

    Understanding forgetting from working memory, the memory used in ongoing cognitive processing, is critical to understanding human cognition. In the past decade, a number of conflicting findings have been reported regarding the role of time in forgetting from working memory. This has led to a debate concerning whether longer retention intervals…

  8. True or false? Memory is differentially affected by stress-induced cortisol elevations and sympathetic activity at consolidation and retrieval.

    Science.gov (United States)

    Smeets, Tom; Otgaar, Henry; Candel, Ingrid; Wolf, Oliver T

    2008-11-01

    Adrenal stress hormones released in response to acute stress may yield memory-enhancing effects when released post-learning and impairing effects at memory retrieval, especially for emotional memory material. However, so far these differential effects of stress hormones on the various memory phases for neutral and emotional memory material have not been demonstrated within one experiment. This study investigated whether, in line with their effects on true memory, stress and stress-induced adrenal stress hormones affect the encoding, consolidation, and retrieval of emotional and neutral false memories. Participants (N=90) were exposed to a stressor before encoding, during consolidation, before retrieval, or were not stressed and then were subjected to neutral and emotional versions of the Deese-Roediger-McDermott word list learning paradigm. Twenty-four hours later, recall of presented words (true recall) and non-presented critical lure words (false recall) was assessed. Results show that stress exposure resulted in superior true memory performance in the consolidation stress group and reduced true memory performance in the retrieval stress group compared to the other groups, predominantly for emotional words. These memory-enhancing and memory-impairing effects were strongly related to stress-induced cortisol and sympathetic activity measured via salivary alpha-amylase levels. Neutral and emotional false recall, on the other hand, was neither affected by stress exposure, nor related to cortisol and sympathetic activity following stress. These results demonstrate the importance of stress-induced hormone-related activity in enhancing memory consolidation and in impairing memory retrieval, in particular for emotional memory material.

  9. Stress Disrupts Context-Dependent Memory

    Science.gov (United States)

    Schwabe, Lars; Bohringer, Andreas; Wolf, Oliver T.

    2009-01-01

    Memory is facilitated when the retrieval context resembles the learning context. The brain structures underlying contextual influences on memory are susceptible to stress. Whether stress interferes with context-dependent memory is still unknown. We exposed healthy adults to stress or a control procedure before they learned an object-location task…

  10. NF-κB Transcription Factor Role in Consolidation and Reconsolidation of Persistent Memories

    Directory of Open Access Journals (Sweden)

    Verónica ede la Fuente

    2015-09-01

    Full Text Available Transcriptional regulation is an important molecular process required for long-term neural plasticity and long-term memory formation. Thus, one main interest in molecular neuroscience in the last decades has been the identification of transcription factors that are involved in memory processes. Among them, the NF-κB family of transcription factors has gained interest due to a significant body of evidence that supports a key role of these proteins in synaptic plasticity and memory. In recent years, the interest was particularly reinforced because NF-κB was characterized as an important regulator of synaptogenesis. This function may be explained by its participation in synapse to nucleus communication, as well as a possible local role at the synapse. This review provides an overview of experimental work obtained in the last years, showing the essential role of this transcription factor in memory processes in different learning tasks in mammals. We focus the review on the consolidation and reconsolidation memory phases as well as on the regulation of immediate-early and late genes by epigenetic mechanisms that determine enduring forms of memories.

  11. NF-κB transcription factor role in consolidation and reconsolidation of persistent memories

    Science.gov (United States)

    de la Fuente, Verónica; Federman, Noel; Zalcman, Gisela; Salles, Angeles; Freudenthal, Ramiro; Romano, Arturo

    2015-01-01

    Transcriptional regulation is an important molecular process required for long-term neural plasticity and long-term memory (LTM) formation. Thus, one main interest in molecular neuroscience in the last decades has been the identification of transcription factors that are involved in memory processes. Among them, the nuclear factor κB (NF-κB) family of transcription factors has gained interest due to a significant body of evidence that supports a key role of these proteins in synaptic plasticity and memory. In recent years, the interest was particularly reinforced because NF-κB was characterized as an important regulator of synaptogenesis. This function may be explained by its participation in synapse to nucleus communication, as well as a possible local role at the synapse. This review provides an overview of experimental work obtained in the last years, showing the essential role of this transcription factor in memory processes in different learning tasks in mammals. We focus the review on the consolidation and reconsolidation memory phases as well as on the regulation of immediate-early and late genes by epigenetic mechanisms that determine enduring forms of memories. PMID:26441513

  12. The influence of catch trials on the consolidation of motor memory in force field adaptation tasks

    Directory of Open Access Journals (Sweden)

    Anne eFocke

    2013-07-01

    Full Text Available In computational neuroscience it is generally accepted that human motor memory contains neural representations of the physics of the musculoskeletal system and the objects in the environment. These representations are called internal models. Force field studies, in which subjects have to adapt to dynamic perturbations induced by a robotic manipulandum, are an established tool to analyze the characteristics of such internal models. The aim of the current study was to investigate whether catch trials during force field learning could influence the consolidation of motor memory in more complex tasks. Thereby, the force field was more than double the force field of previous studies (35 Ns/m. Moreover, the arm of the subjects was not supported. A total of forty-six subjects participated in this study and performed center-out movements at a robotic manipulandum in two different force fields. Two control groups learned force field A on day 1 and were retested in the same force field on day 3 (AA. Two test groups additionally learned an interfering force field B (=-A on day 2 (ABA. The difference between the two test and control groups, respectively, was the absence (0% or presence (19% of catch trials, in which the force field was turned off suddenly. The results showed consolidation of force field A on day 3 for both control groups. Test groups showed no consolidation of force field A (19% catch trials and even poorer performance on day 3 (0% catch trials. In conclusion, it can be stated that catch trials seem to have a positive effect on the performance on day 3 but do not trigger a consolidation process as shown in previous studies that used a lower force field viscosity with supported arm. These findings indicate that the results of previous studies in which less complex tasks were analyzed, cannot be fully transferred to more complex tasks. Moreover, the effects of catch trials in these situations are insufficiently understood and further research

  13. Evaluation Effects of Verapamil as a Calcium Channel Blocker on Acquisition, Consolidation and Retrieval of Memory in Mice

    Directory of Open Access Journals (Sweden)

    Nooshin Masoudian

    2015-04-01

    Full Text Available Many factors are involved in learning and memory processes including brain nuclei, neurotransmitter systems, and the activity of ion channels. Studies showed inconsistent effects of calcium channel blockers on learning process, especially memory consolidation; however, little is known about their effect on memory acquisition and retrieval. Accordingly, the present study aimed to determine the effects of verapamil calcium channel antagonist as a representative of the phenylalkylamine group on different stages of memory and learning processes including acquisition, consolidation and retrieval in mice. In this experimental study, 150 male albino mice with a mean weight of 30 g were used. The mice were trained in a passive avoidance-learning task (1 mA shock for 2 seconds for evaluation of memory acquisition and consolidation and 3 seconds for evaluation of memory retrieval. The effect of verapamil (1, 2.5, 5, 10, and 20 mg/kg on memory consolidation and the most effective dose of consolidation phase on memory acquisition and retrieval was assessed. For the evaluation of memory consolidation, the animals received the drug intraperitoneally immediately after training, while for evaluation of memory acquisition and retrieval, the drug was injected one hour before training. Memory retrieval test was performed 48 hours after training (the length of time it took the animal to enter the dark part of the device. The results showed that verapamil injection exerted no effect on memory acquisition and consolidation; nevertheless, it was capable to disrupt memory retrieval in 10 and 20 mg doses. These results indicate that as a phenylalkylamine calcium channel antagonist, high doses of verapamil can impair memory. Normal 0 false false false EN-US X-NONE AR-SA /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso

  14. Does sleep play a role in memory consolidation? A comparative test.

    Directory of Open Access Journals (Sweden)

    Isabella Capellini

    Full Text Available Sleep is a pervasive characteristic of mammalian species, yet its purpose remains obscure. It is often proposed that 'sleep is for the brain', a view that is supported by experimental studies showing that sleep improves cognitive processes such as memory consolidation. Some comparative studies have also reported that mammalian sleep durations are higher among more encephalized species. However, no study has assessed the relationship between sleep and the brain structures that are implicated in specific cognitive processes across species. The hippocampus, neocortex and amygdala are important for memory consolidation and learning and are also in a highly actived state during sleep. We therefore investigated the evolutionary relationship between mammalian sleep and the size of these brain structures using phylogenetic comparative methods. We found that evolutionary increases in the size of the amygdala are associated with corresponding increases in NREM sleep durations. These results are consistent with the hypothesis that NREM sleep is functionally linked with specializations of the amygdala, including perhaps memory processing.

  15. Light sleep versus slow wave sleep in memory consolidation: a question of global versus local processes?

    Science.gov (United States)

    Genzel, Lisa; Kroes, Marijn C W; Dresler, Martin; Battaglia, Francesco P

    2014-01-01

    Sleep is strongly involved in memory consolidation, but its role remains unclear. 'Sleep replay', the active potentiation of relevant synaptic connections via reactivation of patterns of network activity that occurred during previous experience, has received considerable attention. Alternatively, sleep has been suggested to regulate synaptic weights homeostatically and nonspecifically, thereby improving the signal:noise ratio of memory traces. Here, we reconcile these theories by highlighting the distinction between light and deep nonrapid eye movement (NREM) sleep. Specifically, we draw on recent studies to suggest a link between light NREM and active potentiation, and between deep NREM and homeostatic regulation. This framework could serve as a key for interpreting the physiology of sleep stages and reconciling inconsistencies in terminology in this field.

  16. An overview of the neuro-cognitive processes involved in the encoding, consolidation, and retrieval of true and false memories

    Directory of Open Access Journals (Sweden)

    Straube Benjamin

    2012-07-01

    Full Text Available Abstract Perception and memory are imperfect reconstructions of reality. These reconstructions are prone to be influenced by several factors, which may result in false memories. A false memory is the recollection of an event, or details of an episode, that did not actually occur. Memory formation comprises at least three different sub-processes: encoding, consolidation and the retrieval of the learned material. All of these sub-processes are vulnerable for specific errors and consequently may result in false memories. Whereas, processes like imagery, self-referential encoding or spreading activation can lead to the formation of false memories at encoding, semantic generalization during sleep and updating processes due to misleading post event information, in particular, are relevant at the consolidation stage. Finally at the retrieval stage, monitoring processes, which are assumed to be essential to reject false memories, are of specific importance. Different neuro-cognitive processes have been linked to the formation of true and false memories. Most consistently the medial temporal lobe and the medial and lateral prefrontal cortex have been reported with regard to the formation of true and false memories. Despite the fact that all phases entailing memory formation, consolidation of stored information and retrieval processes, are relevant for the forming of false memories, most studies focused on either memory encoding or retrieval. Thus, future studies should try to integrate data from all phases to give a more comprehensive view on systematic memory distortions. An initial outline is developed within this review to connect the different memory stages and research strategies.

  17. The intra-hippocampal leucine administration impairs memory consolidation and LTP generation in rats.

    Science.gov (United States)

    Glaser, Viviane; Carlini, Valeria P; Gabach, Laura; Ghersi, Marisa; de Barioglio, Susana Rubiales; Ramirez, Oscar A; Perez, Mariela F; Latini, Alexandra

    2010-10-01

    Leucine accumulates in fluids and tissues of patients affected by maple syrup urine disease, an inherited metabolic disorder, predominantly characterized by neurological dysfunction. Although, a variable degree of cognition/psychomotor delay/mental retardation is found in a considerable number of individuals affected by this deficiency, the mechanisms underlying the neuropathology of these alterations are still not defined. Therefore, the aim of this study was to investigate the effect of acute intra-hippocampal leucine administration in the step-down test in rats. In addition, the leucine effects on the electrophysiological parameter, long-term potentiation generation, and on the activities of the respiratory chain were also investigated. Male Wistar rats were bilaterally administrated with leucine (80 nmol/hippocampus; 160 nmol/rat) or artificial cerebrospinal fluid (controls) into the hippocampus immediately post-training in the behavioral task. Twenty-four hours after training in the step-down test, the latency time was evaluated and afterwards animals were sacrificed for assessing the ex vivo biochemical measurements. Leucine-treated animals showed impairment in memory consolidation and a complete inhibition of long-term potentiation generation at supramaximal stimulation. In addition, a significant increment in complex IV activity was observed in hippocampus from leucine-administered rats. These data strongly indicate that leucine compromise memory consolidation, and that impairment of long-term potentiation generation and unbalance of the respiratory chain may be plausible mechanisms underlying the deleterious leucine effect on cognition.

  18. Increased entorhinal-prefrontal theta synchronization parallels decreased entorhinal-hippocampal theta synchronization during learning and consolidation of associative memory.

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    Kaori eTakehara-Nishiuchi

    2012-01-01

    Full Text Available Memories are thought to be encoded as a distributed representation in the neocortex. The medial prefrontal cortex (mPFC has been shown to support the expression of memories that initially depend on the hippocampus (HPC, yet the mechanisms by which the HPC and mPFC access the distributed representations in the neocortex are unknown. By measuring phase synchronization of local field potential (LFP oscillations, we found that learning initiated changes in neuronal communication of the HPC and mPFC with the lateral entorhinal cortex (LEC, an area that is connected with many other neocortical regions. LFPs were recorded simultaneously from the three brain regions while rats formed an association between an auditory stimulus (CS and eyelid stimulation (US in a trace eyeblink conditioning paradigm, as well as during retention one month following learning. Over the course of learning, theta oscillations in the LEC and mPFC became strongly synchronized following the presentation of the CS on trials in which rats exhibited a conditioned response (CR, and this strengthened synchronization was also observed during retention one month after learning. In contrast, CS-evoked theta synchronization between the LEC and HPC decreased with learning. Our results suggest that the communication between the LEC and mPFC is strengthened with learning whereas the communication between the LEC and HPC is concomitantly weakened, suggesting that enhanced LEC-mPFC communication may be a key process for theoretically-proposed neocortical reorganization accompanying encoding and consolidation of a memory.

  19. Changes in corticospinal excitability during consolidation predict acute exercise-induced off-line gains in procedural memory.

    Science.gov (United States)

    Ostadan, Fatemeh; Centeno, Carla; Daloze, Jean-Felix; Frenn, Mira; Lundbye-Jensen, Jesper; Roig, Marc

    2016-12-01

    A single bout of cardiovascular exercise performed immediately after practicing a motor task improves the long-term retention of the skill through an optimization of memory consolidation. However, the specific brain mechanisms underlying the effects of acute cardiovascular exercise on procedural memory are poorly understood. We sought to determine if a single bout of exercise modifies corticospinal excitability (CSE) during the early stages of memory consolidation. In addition, we investigated if changes in CSE are associated with exercise-induced off-line gains in procedural memory. Participants practiced a serial reaction time task followed by either a short bout of acute exercise or a similar rest period. To monitor changes in CSE we used transcranial magnetic stimulation applied to the primary motor cortex (M1) at baseline, 15, 35, 65 and 125min after exercise or rest. Participants in the exercise condition showed larger (∼24%) improvements in procedural memory through consolidation although differences between groups did not reach statistical significance. Exercise promoted an increase in CSE, which remained elevated 2h after exercise. More importantly, global increases in CSE following exercise correlated with the magnitude of off-line gains in skill level assessed in a retention test performed 8h after motor practice. A single bout of exercise modulates short-term neuroplasticity mechanisms subserving consolidation processes that predict off-line gains in procedural memory. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Neurons activated during fear memory consolidation and reconsolidation are mapped to a common and new topography in the lateral amygdala.

    Science.gov (United States)

    Bergstrom, Hadley C; McDonald, Craig G; Dey, Smita; Fernandez, Gina M; Johnson, Luke R

    2013-07-01

    A key question in neuroscience is how memory is selectively allocated to neural networks in the brain. This question remains a significant research challenge, in both rodent models and humans alike, because of the inherent difficulty in tracking and deciphering large, highly dimensional neuronal ensembles that support memory (i.e., the engram). In a previous study we showed that consolidation of a new fear memory is allocated to a common topography of amygdala neurons. When a consolidated memory is retrieved, it may enter a labile state, requiring reconsolidation for it to persist. What is not known is whether the original spatial allocation of a consolidated memory changes during reconsolidation. Knowledge about the spatial allocation of a memory, during consolidation and reconsolidation, provides fundamental insight into its core physical structure (i.e., the engram). Using design-based stereology, we operationally define reconsolidation by showing a nearly identical quantity of neurons in the dorsolateral amygdala (LAd) that expressed a plasticity-related protein, phosphorylated mitogen-activated protein kinase, following both memory acquisition and retrieval. Next, we confirm that Pavlovian fear conditioning recruits a stable, topographically organized population of activated neurons in the LAd. When the stored fear memory was briefly reactivated in the presence of the relevant conditioned stimulus, a similar topography of activated neurons was uncovered. In addition, we found evidence for activated neurons allocated to new regions of the LAd. These findings provide the first insight into the spatial allocation of a fear engram in the LAd, during its consolidation and reconsolidation phase.

  1. Time- but not sleep-dependent consolidation of tDCS-enhanced visuomotor skills.

    Science.gov (United States)

    Reis, Janine; Fischer, Jan Torben; Prichard, George; Weiller, Cornelius; Cohen, Leonardo G; Fritsch, Brita

    2015-01-01

    Consolidation of motor skills after training can occur in a time- or sleep-dependent fashion. Recent studies revealed time-dependent consolidation as a common feature of visuomotor tasks. We have previously shown that anodal transcranial direct current stimulation (tDCS) in combination with repeated motor training benefits consolidation by the induction of offline skill gains in a complex visuomotor task, preventing the regular occurrence of skill loss between days. Here, we asked 2 questions: What is the time course of consolidation between days for this task and do exogenously induced offline gains develop as a function of time or overnight sleep? We found that both the development of offline skill loss in sham-stimulated subjects and offline skill gains induced by anodal tDCS critically depend on the passage of time after training, but not on overnight sleep. These findings support the view that tDCS interacts directly with the physiological consolidation process. However, in a control experiment, anodal tDCS applied after the training did not induce skill gains, implying that coapplication of tDCS and training is required to induce offline skill gains, pointing to the initiation of consolidation already during training.

  2. Procedural and declarative memory task performance, and the memory consolidation function of sleep, in recent and abstinent ecstasy/MDMA users.

    Science.gov (United States)

    Blagrove, Mark; Seddon, Jennifer; George, Sophie; Parrott, Andrew C; Stickgold, Robert; Walker, Matthew P; Jones, Katy A; Morgan, Michael J

    2011-04-01

    Ecstasy/MDMA use has been associated with various memory deficits. This study assessed declarative and procedural memory in ecstasy/MDMA users. Participants were tested in two sessions, 24 h apart, so that the memory consolidation function of sleep on both types of memory could also be assessed. Groups were: drug-naive controls (n = 24); recent ecstasy/MDMA users, who had taken ecstasy/MDMA 2-3 days before the first testing session (n = 25), and abstinent users, who had not taken ecstasy/MDMA for at least 8 days before testing (n = 17). Procedural memory did not differ between groups, but greater lifetime consumption of ecstasy was associated with poorer procedural memory. Recent ecstasy/MDMA users who had taken other drugs (mainly cannabis) 48-24 h before testing exhibited poorer declarative memory than controls, but recent users who had not taken other drugs in this 48-24-h period did not differ from controls. Greater lifetime consumption of ecstasy, and of cocaine, were associated with greater deficits in declarative memory. These results suggest that procedural, as well as declarative, memory deficits are associated with the extent of past ecstasy use. However, ecstasy/MDMA did not affect the memory consolidation function of sleep for either the declarative or the procedural memory task.

  3. Lithium prevents REM sleep deprivation-induced impairments on memory consolidation.

    Science.gov (United States)

    Ota, Simone M; Moreira, Karin Di Monteiro; Suchecki, Deborah; Oliveira, Maria Gabriela M; Tiba, Paula A

    2013-11-01

    Pre-training rapid eye movement sleep (REMS) deprivation affects memory acquisition and/or consolidation. It also produces major REMS rebound at the cost of waking and slow wave sleep (SWS). Given that both SWS and REMS appear to be important for memory processes, REMS rebound after training may disrupt the organization of sleep cycles, i.e., excessive amount of REMS and/or little SWS after training could be harmful for memory formation. To examine whether lithium, a drug known to increase SWS and reduce REMS, could prevent the memory impairment induced by pre-training sleep deprivation. Animals were divided in 2 groups: cage control (CC) and REMS-deprived (REMSDep), and then subdivided into 4 subgroups, treated either with vehicle or 1 of 3 doses of lithium (50, 100, and 150 mg/kg) 2 h before training on the multiple trial inhibitory avoidance task. Animals were tested 48 h later to make sure that the drug had been already metabolized and eliminated. Another set of animals was implanted with electrodes and submitted to the same experimental protocol for assessment of drug-induced sleep-wake changes. Wistar male rats weighing 300-400 g. Sleep deprived rats required more trials to learn the task and still showed a performance deficit during test, except from those treated with 150 mg/kg of lithium, which also reduced the time spent in REM sleep during sleep recovery. Lithium reduced rapid eye movement sleep and prevented memory impairment induced by sleep deprivation. These results indicate that these phenomena may be related, but cause-effect relationship cannot be ascertained.

  4. Exercise-induced noradrenergic activation enhances memory consolidation in both normal aging and patients with amnestic mild cognitive impairment.

    Science.gov (United States)

    Segal, Sabrina K; Cotman, Carl W; Cahill, Lawrence F

    2012-01-01

    Post-trial pharmacological activation of the noradrenergic system can facilitate memory consolidation. Because exercise activates the locus coeruleus and increases brain norepinephrine release, we hypothesized that post-trial exercise could function as a natural stimulus to enhance memory consolidation. We investigated this in amnestic mild cognitive impairment (aMCI) and cognitively normal elderly individuals by examining the effects of an acute bout of post-learning, aerobic exercise (6 minutes at 70% VO2 max on a stationary bicycle) on memory for some emotional images. Exercise significantly elevated endogenous norepinephrine (measured via the biomarker, salivary alpha-amylase) in both aMCI patients and controls. Additionally, exercise retrogradely enhanced memory in both aMCI patients and controls. Acute exercise that activates the noradrenergic system may serve as a beneficial, natural, and practical therapeutic intervention for cognitive decline in the aging population.

  5. Tracking the Time-Dependent Role of the Hippocampus in Memory Recall Using DREADDs.

    Science.gov (United States)

    Varela, Carmen; Weiss, Sarah; Meyer, Retsina; Halassa, Michael; Biedenkapp, Joseph; Wilson, Matthew A; Goosens, Ki Ann; Bendor, Daniel

    2016-01-01

    The hippocampus is critical for the storage of new autobiographical experiences as memories. Following an initial encoding stage in the hippocampus, memories undergo a process of systems-level consolidation, which leads to greater stability through time and an increased reliance on neocortical areas for retrieval. The extent to which the retrieval of these consolidated memories still requires the hippocampus is unclear, as both spared and severely degraded remote memory recall have been reported following post-training hippocampal lesions. One difficulty in definitively addressing the role of the hippocampus in remote memory retrieval is the precision with which the entire volume of the hippocampal region can be inactivated. To address this issue, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs), a chemical-genetic tool capable of highly specific neuronal manipulation over large volumes of brain tissue. We find that remote (>7 weeks after acquisition), but not recent (1-2 days after acquisition) contextual fear memories can be recalled after injection of the DREADD agonist (CNO) in animals expressing the inhibitory DREADD in the entire hippocampus. Our data demonstrate a time-dependent role of the hippocampus in memory retrieval, supporting the standard model of systems consolidation.

  6. Tracking the Time-Dependent Role of the Hippocampus in Memory Recall Using DREADDs.

    Directory of Open Access Journals (Sweden)

    Carmen Varela

    Full Text Available The hippocampus is critical for the storage of new autobiographical experiences as memories. Following an initial encoding stage in the hippocampus, memories undergo a process of systems-level consolidation, which leads to greater stability through time and an increased reliance on neocortical areas for retrieval. The extent to which the retrieval of these consolidated memories still requires the hippocampus is unclear, as both spared and severely degraded remote memory recall have been reported following post-training hippocampal lesions. One difficulty in definitively addressing the role of the hippocampus in remote memory retrieval is the precision with which the entire volume of the hippocampal region can be inactivated. To address this issue, we used Designer Receptors Exclusively Activated by Designer Drugs (DREADDs, a chemical-genetic tool capable of highly specific neuronal manipulation over large volumes of brain tissue. We find that remote (>7 weeks after acquisition, but not recent (1-2 days after acquisition contextual fear memories can be recalled after injection of the DREADD agonist (CNO in animals expressing the inhibitory DREADD in the entire hippocampus. Our data demonstrate a time-dependent role of the hippocampus in memory retrieval, supporting the standard model of systems consolidation.

  7. The interplay of attention and consciousness in visual search, attentional blink and working memory consolidation.

    Science.gov (United States)

    Raffone, Antonino; Srinivasan, Narayanan; van Leeuwen, Cees

    2014-05-05

    Despite the acknowledged relationship between consciousness and attention, theories of the two have mostly been developed separately. Moreover, these theories have independently attempted to explain phenomena in which both are likely to interact, such as the attentional blink (AB) and working memory (WM) consolidation. Here, we make an effort to bridge the gap between, on the one hand, a theory of consciousness based on the notion of global workspace (GW) and, on the other, a synthesis of theories of visual attention. We offer a theory of attention and consciousness (TAC) that provides a unified neurocognitive account of several phenomena associated with visual search, AB and WM consolidation. TAC assumes multiple processing stages between early visual representation and conscious access, and extends the dynamics of the global neuronal workspace model to a visual attentional workspace (VAW). The VAW is controlled by executive routers, higher-order representations of executive operations in the GW, without the need for explicit saliency or priority maps. TAC leads to newly proposed mechanisms for illusory conjunctions, AB, inattentional blindness and WM capacity, and suggests neural correlates of phenomenal consciousness. Finally, the theory reconciles the all-or-none and graded perspectives on conscious representation.

  8. Retro-Active Emotion: Do Negative Emotional Stimuli Disrupt Consolidation in Working Memory?

    Science.gov (United States)

    Kandemir, Güven; Akyürek, Elkan G.; Nieuwenstein, Mark R.

    2017-01-01

    While many studies have shown that a task-irrelevant emotionally arousing stimulus can interfere with the processing of a shortly following target, it remains unclear whether an emotional stimulus can also retro-actively interrupt the ongoing processing of an earlier target. In two experiments, we examined whether the presentation of a negative emotionally arousing picture can disrupt working memory consolidation of a preceding visual target. In both experiments, the effects of negative emotional pictures were compared with the effects of neutral pictures. In Experiment 1, the pictures were entirely task-irrelevant whereas in Experiment 2 the pictures were associated with a 2-alternative forced choice task that required participants to respond to the color of a frame surrounding the pictures. The results showed that the appearance of the pictures did not interfere with target consolidation when the pictures were task-irrelevant, whereas such interference was observed when the pictures were associated with a 2-AFC task. Most importantly, however, the results showed no effects of whether the picture had neutral or emotional content. Implications for further research are discussed. PMID:28103267

  9. Memory suppression trades prolonged fear and sleep-dependent fear plasticity for the avoidance of current fear

    Science.gov (United States)

    Kuriyama, Kenichi; Honma, Motoyasu; Yoshiike, Takuya; Kim, Yoshiharu

    2013-07-01

    Sleep deprivation immediately following an aversive event reduces fear by preventing memory consolidation during homeostatic sleep. This suggests that acute insomnia might act prophylactically against the development of posttraumatic stress disorder (PTSD) even though it is also a possible risk factor for PTSD. We examined total sleep deprivation and memory suppression to evaluate the effects of these interventions on subsequent aversive memory formation and fear conditioning. Active suppression of aversive memory impaired retention of event memory. However, although the remembered fear was more reduced in sleep-deprived than sleep-control subjects, suppressed fear increased, and seemed to abandon the sleep-dependent plasticity of fear. Active memory suppression, which provides a psychological model for Freud's ego defense mechanism, enhances fear and casts doubt on the potential of acute insomnia as a prophylactic measure against PTSD. Our findings bring into question the role of sleep in aversive-memory consolidation in clinical PTSD pathophysiology.

  10. Effect of emotional and neutral declarative memory consolidation on sleep architecture.

    Science.gov (United States)

    Ward, Marcus P; Peters, Kevin R; Smith, Carlyle T

    2014-05-01

    The relationship between emotional or neutral declarative memory consolidation and sleep architecture was investigated. Thirty university students (21 females) viewed negative, neutral, or positive pictures and rated their valence and arousal in the evening. Participants performed a recognition test 1 h later and then underwent overnight polysomnography. Their post-encoding sleep architecture was compared to a baseline night. Participants returned 6 days following encoding for a second recognition test. Results showed no group (Negative, Neutral, Positive) differences in recognition 1 h or 6 days following encoding. Stage 2 sleep spindle density decreased across all groups following encoding, and recognition after 6 days was positively correlated with Stage 2 sleep spindle density on both nights. There was no change in REM density in any of the groups. This is the first investigation into phasic sleep microarchitecture changes following emotional and neutral declarative learning. Future investigations may benefit from more salient emotional stimuli.

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

    Science.gov (United States)

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

    1998-01-01

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

  12. Atypical Acquisition and Atypical Expression of Memory Consolidation Gains in a Motor Skill in Young Female Adults with ADHD

    Science.gov (United States)

    Adi-Japha, Esther; Fox, Orly; Karni, Avi

    2011-01-01

    Individuals with ADHD often show performance deficits in motor tasks. It is not clear, however, whether this reflects less effective acquisition of skill (procedural knowledge), or deficient consolidation into long-term memory, in ADHD. The aim of the study was to compare the acquisition of skilled motor performance, the expression of…

  13. Atypical Acquisition and Atypical Expression of Memory Consolidation Gains in a Motor Skill in Young Female Adults with ADHD

    Science.gov (United States)

    Adi-Japha, Esther; Fox, Orly; Karni, Avi

    2011-01-01

    Individuals with ADHD often show performance deficits in motor tasks. It is not clear, however, whether this reflects less effective acquisition of skill (procedural knowledge), or deficient consolidation into long-term memory, in ADHD. The aim of the study was to compare the acquisition of skilled motor performance, the expression of…

  14. Hippocampal memory consolidation during sleep: a comparison of mammals and birds.

    Science.gov (United States)

    Rattenborg, Niels C; Martinez-Gonzalez, Dolores; Roth, Timothy C; Pravosudov, Vladimir V

    2011-08-01

    The transition from wakefulness to sleep is marked by pronounced changes in brain activity. The brain rhythms that characterize the two main types of mammalian sleep, slow-wave sleep (SWS) and rapid eye movement (REM) sleep, are thought to be involved in the functions of sleep. In particular, recent theories suggest that the synchronous slow-oscillation of neocortical neuronal membrane potentials, the defining feature of SWS, is involved in processing information acquired during wakefulness. According to the Standard Model of memory consolidation, during wakefulness the hippocampus receives input from neocortical regions involved in the initial encoding of an experience and binds this information into a coherent memory trace that is then transferred to the neocortex during SWS where it is stored and integrated within preexisting memory traces. Evidence suggests that this process selectively involves direct connections from the hippocampus to the prefrontal cortex (PFC), a multimodal, high-order association region implicated in coordinating the storage and recall of remote memories in the neocortex. The slow-oscillation is thought to orchestrate the transfer of information from the hippocampus by temporally coupling hippocampal sharp-wave/ripples (SWRs) and thalamocortical spindles. SWRs are synchronous bursts of hippocampal activity, during which waking neuronal firing patterns are reactivated in the hippocampus and neocortex in a coordinated manner. Thalamocortical spindles are brief 7-14 Hz oscillations that may facilitate the encoding of information reactivated during SWRs. By temporally coupling the readout of information from the hippocampus with conditions conducive to encoding in the neocortex, the slow-oscillation is thought to mediate the transfer of information from the hippocampus to the neocortex. Although several lines of evidence are consistent with this function for mammalian SWS, it is unclear whether SWS serves a similar function in birds, the only

  15. Hippocampal memory consolidation during sleep: a comparison of mammals and birds

    Science.gov (United States)

    Rattenborg, Niels C.; Martinez-Gonzalez, Dolores; Roth, Timothy C.; Pravosudov, Vladimir V.

    2010-01-01

    The transition from wakefulness to sleep is marked by pronounced changes in brain activity. The brain rhythms that characterize the two main types of mammalian sleep, slow-wave sleep (SWS) and rapid eye movement (REM) sleep, are thought to be involved in the functions of sleep. In particular, recent theories suggest that the synchronous slow-oscillation of neocortical neuronal membrane potentials, the defining feature of SWS, is involved in processing information acquired during wakefulness. According to the Standard Model of memory consolidation, during wakefulness the hippocampus receives input from neocortical regions involved in the initial encoding of an experience and binds this information into a coherent memory trace that is then transferred to the neocortex during SWS where it is stored and integrated within preexisting memory traces. Evidence suggests that this process selectively involves direct connections from the hippocampus to the prefrontal cortex (PFC), a multimodal, high-order association region implicated in coordinating the storage and recall of remote memories in the neocortex. The slow-oscillation is thought to orchestrate the transfer of information from the hippocampus by temporally coupling hippocampal sharp-wave/ripples (SWRs) and thalamocortical spindles. SWRs are synchronous bursts of hippocampal activity, during which waking neuronal firing patterns are reactivated in the hippocampus and neocortex in a coordinated manner. Thalamocortical spindles are brief 7–14 Hz oscillations that may facilitate the encoding of information reactivated during SWRs. By temporally coupling the readout of information from the hippocampus with conditions conducive to encoding in the neocortex, the slow-oscillation is thought to mediate the transfer of information from the hippocampus to the neocortex. Although several lines of evidence are consistent with this function for mammalian SWS, it is unclear whether SWS serves a similar function in birds, the

  16. Chicks incubated in hypomagnetic field need more exogenous noradrenaline for memory consolidation

    Science.gov (United States)

    Xiao, Ying; Wang, Qian; Xu, Mu-Ling; Jiang, Jin-Chang; Li, Bing

    2009-07-01

    The geomagnetic field (GMF) is one of the essential characteristics of the terrestrial environment but does not apply in outer space. The elimination of GMF may interfere with the normal activities of life in many aspects. Previous behavioral experiments have found that long-term memory is impaired in chicks incubated in a near-zero magnetic environment (i.e. hypomagnetic field or HMF). The present study was designed to evaluate the possible involvement of noradrenergic change in the functional abnormality observed before. A HMF space was produced by nullifying the natural GMF with three pairs of Helmholtz coils. The one-trial passive avoidance learning paradigm was performed on day-old chicks incubated in either the HMF space or the natural GMF. Exogenous noradrenaline was administered by intracerebral injections and the effect on memory consolidation was compared between the two categories of subjects. In the behavioral paradigm, the HMF chicks had a higher elimination rate than the GMF chicks and displayed a significant reduction in overall responsiveness. The administration of moderate doses (0.1-0.5 nmol/hemisphere) of noradrenaline led to fairly good memory retention in GMF chicks but had little effect on HMF chicks. However, long-term memory of HMF chicks could be elevated to the normal level by much higher doses (1.0-1.75 nmol/hem) of the drug. These results suggest that prolonged exposure to HMF may induce disorders in the noradrenergic system in the brain and indicate a potentiality of counteracting the ill-effect of GMF deprivation with appropriate pharmacological manipulation.

  17. Circadian Oscillations within the Hippocampus Support Hippocampus-dependent Memory Processing

    Directory of Open Access Journals (Sweden)

    Kristin Lynn Eckel-Mahan

    2012-04-01

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

  18. Effects of Concurrent and Delayed Visual Feedback on Motor Memory Consolidation.

    Science.gov (United States)

    Wang, Dangxiao; Li, Teng; Yang, Gaofeng; Zhang, Yuru

    2017-02-22

    In many domains, it's important to understand the ways in which humans learn and develop new motor skills effectively and efficiently. For example, in dental operations, the ability to apply a weak force with a required tolerance is a fundamental skill to ensure diagnostic and treatment outcome, but acquiring such a skill is a challenge for novices. In this paper, we focus on motor memory for producing normally applied force by a hand-held probe and we compare the effects of two feedback methods on motor memory consolidation. Fourteen participants were randomly assigned to two groups: a Concurrent Group and a Delayed Group. Participants in the Concurrent Group were trained to apply a target force with concurrent visual feedback, while those in the Delayed Group were trained with delayed visual feedback. The task included two phases: a Training/Testing Phase, and a Retention Phase. The results indicated that participants in the Delayed Group obtained more effective learning outcomes and better retention effects. These findings provide a new perspective to explore the relationship between feedback methods and the cognitive process of motor skill learning, and open a new way to train motor skill using more effective methods than the traditional concurrent feedback approaches.

  19. Pharmacological differences between memory consolidation of habituation to an open field and inhibitory avoidance learning

    Directory of Open Access Journals (Sweden)

    Vianna M.R.M.

    2001-01-01

    Full Text Available Rats implanted bilaterally with cannulae in the CA1 region of the dorsal hippocampus or the entorhinal cortex were submitted to either a one-trial inhibitory avoidance task, or to 5 min of habituation to an open field. Immediately after training, they received intrahippocampal or intraentorhinal 0.5-µl infusions of saline, of a vehicle (2% dimethylsulfoxide in saline, of the glutamatergic N-methyl-D-aspartate (NMDA receptor antagonist 2-amino-5-phosphono pentanoic acid (AP5, of the protein kinase A inhibitor Rp-cAMPs (0.5 µg/side, of the calcium-calmodulin protein kinase II inhibitor KN-62, of the dopaminergic D1 antagonist SCH23390, or of the mitogen-activated protein kinase kinase inhibitor PD098059. Animals were tested in each task 24 h after training. Intrahippocampal KN-62 was amnestic for habituation; none of the other treatments had any effect on the retention of this task. In contrast, all of them strongly affected memory of the avoidance task. Intrahippocampal Rp-cAMPs, KN-62 and AP5, and intraentorhinal Rp-cAMPs, KN-62, PD098059 and SCH23390 caused retrograde amnesia. In view of the known actions of the treatments used, the present findings point to important biochemical differences in memory consolidation processes of the two tasks.

  20. Amyloid β Enhances Typical Rodent Behavior While It Impairs Contextual Memory Consolidation

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    Karla Salgado-Puga

    2015-01-01

    Full Text Available Alzheimer’s disease (AD is associated with an early hippocampal dysfunction, which is likely induced by an increase in soluble amyloid beta peptide (Aβ. This hippocampal failure contributes to the initial memory deficits observed both in patients and in AD animal models and possibly to the deterioration in activities of daily living (ADL. One typical rodent behavior that has been proposed as a hippocampus-dependent assessment model of ADL in mice and rats is burrowing. Despite the fact that AD transgenic mice show some evidence of reduced burrowing, it has not been yet determined whether or not Aβ can affect this typical rodent behavior and whether this alteration correlates with the well-known Aβ-induced memory impairment. Thus, the purpose of this study was to test whether or not Aβ affects burrowing while inducing hippocampus-dependent memory impairment. Surprisingly, our results show that intrahippocampal application of Aβ increases burrowing while inducing memory impairment. We consider that this Aβ-induced increase in burrowing might be associated with a mild anxiety state, which was revealed by increased freezing behavior in the open field, and conclude that Aβ-induced hippocampal dysfunction is reflected in the impairment of ADL and memory, through mechanisms yet to be determined.

  1. Does consolidation of visuospatial sequence knowledge depend on eye movements?

    Science.gov (United States)

    Coomans, Daphné; Vandenbossche, Jochen; Homblé, Koen; Van den Bussche, Eva; Soetens, Eric; Deroost, Natacha

    2014-01-01

    In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT) task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM) condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM) condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  2. Does consolidation of visuospatial sequence knowledge depend on eye movements?

    Directory of Open Access Journals (Sweden)

    Daphné Coomans

    Full Text Available In the current study, we assessed whether visuospatial sequence knowledge is retained over 24 hours and whether this retention is dependent on the occurrence of eye movements. Participants performed two sessions of a serial reaction time (SRT task in which they had to manually react to the identity of a target letter pair presented in one of four locations around a fixation cross. When the letter pair 'XO' was presented, a left response had to be given, when the letter pair 'OX' was presented, a right response was required. In the Eye Movements (EM condition, eye movements were necessary to perform the task since the fixation cross and the target were separated by at least 9° visual angle. In the No Eye Movements (NEM condition, on the other hand, eye movements were minimized by keeping the distance from the fixation cross to the target below 1° visual angle and by limiting the stimulus presentation to 100 ms. Since the target identity changed randomly in both conditions, no manual response sequence was present in the task. However, target location was structured according to a deterministic sequence in both the EM and NEM condition. Learning of the target location sequence was determined at the end of the first session and 24 hours after initial learning. Results indicated that the sequence learning effect in the SRT task diminished, yet remained significant, over the 24 hour interval in both conditions. Importantly, the difference in eye movements had no impact on the transfer of sequence knowledge. These results suggest that the retention of visuospatial sequence knowledge occurs alike, irrespective of whether this knowledge is supported by eye movements or not.

  3. Epigenetic regulation of estrogen-dependent memory

    Science.gov (United States)

    Fortress, Ashley M.; Frick, Karyn M.

    2014-01-01

    Hippocampal memory formation is highly regulated by post-translational histone modifications and DNA methylation. Accordingly, these epigenetic processes play a major role in the effects of modulatory factors, such as sex steroid hormones, on hippocampal memory. Our laboratory recently demonstrated that the ability of the potent estrogen 17β-estradiol (E2) to enhance hippocampal-dependent novel object recognition memory in ovariectomized female mice requires ERK-dependent histone H3 acetylation and DNA methylation in the dorsal hippocampus. Although these data provide valuable insight into the chromatin modifications that mediate the memory-enhancing effects of E2, epigenetic regulation of gene expression is enormously complex. Therefore, more research is needed to fully understand how E2 and other hormones employ epigenetic alterations to shape behavior. This review discusses the epigenetic alterations shown thus far to regulate hippocampal memory, briefly reviews the effects of E2 on hippocampal function, and describes in detail our work on epigenetic regulation of estrogenic memory enhancement. PMID:24878494

  4. 睡眠影响记忆巩固的研究进展%Effect of Sleep on Memory Consolidation

    Institute of Scientific and Technical Information of China (English)

    盛兆福; 张永鹤

    2013-01-01

    学习后睡眠有利于记忆巩固,学习的类型不同,睡眠依赖的记忆巩固机制可能也有所不同,涉及到不同脑区在不同的睡眠时相的生理功能。睡眠有助于长时程增强(long-term potentiation,LTP)的形成,进而促进记忆的巩固。总睡眠剥夺、快动眼睡眠剥夺、片段性睡眠可以通过不同的分子生物学机制损伤记忆巩固。%Delayed post learning sleep but not wakefulness enhances memory consolidation. Different types of learning have unique sleep-related memory consolidation mechanisms that act in dissociable brain regions during different sleep phases throughout the night. Sleep exerts beneficial effect on memory consolidation by improving formation of long-term potentiation. Total sleep deprivation, rapid eye movement sleep deprivation and sleep fragmentation may lead to memory deficits through different molecular mechanisms.

  5. Induction and requirement of gene expression in the anterior cingulate cortex and medial prefrontal cortex for the consolidation of inhibitory avoidance memory

    Directory of Open Access Journals (Sweden)

    Zhang Yue

    2011-01-01

    Full Text Available Abstract Background Memory consolidation is a process to stabilize short-term memory, generating long-term memory. A critical biochemical feature of memory consolidation is a requirement for gene expression. Previous studies have shown that fear memories are consolidated through the activation of gene expression in the amygdala and hippocampus, indicating essential roles of these brain regions in memory formation. However, it is still poorly understood whether gene expression in brain regions other than the amygdala/hippocampus is required for the consolidation of fear memory; however, several brain regions are known to play modulatory roles in fear memory formation. Results To further understand the mechanisms underlying the formation of fear memory, we first identified brain regions where gene expression is activated after learning inhibitory avoidance (IA by analyzing the expression of the immediately early genes c-fos and Arc as markers. Similarly with previous findings, the induction of c-fos and Arc expression was observed in the amygdala and hippocampus. Interestingly, we also observed the induction of c-fos and Arc expression in the medial prefrontal cortex (mPFC: prelimbic (PL and infralimbic (IL regions and Arc expression in the anterior cingulate cortex (ACC. We next examined the roles of these brain regions in the consolidation of IA memory. Consistent with previous findings, inhibiting protein synthesis in the hippocampus blocked the consolidation of IA memory. More importantly, inhibition in the mPFC or ACC also blocked the formation of IA memory. Conclusion Our observations indicated that the formation of IA memory requires gene expression in the ACC and mPFC as well as in the amygdala and hippocampus, suggesting essential roles of the ACC and mPFC in IA memory formation.

  6. REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity

    OpenAIRE

    Médhi Gilson; Gaétane Deliens; Rachel Leproult; Alice Bodart; Antoine Nonclercq; Rudy Ercek; Philippe Peigneux

    2015-01-01

    Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM) sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24) listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min) morning nap. The other half had a long...

  7. Differential Involvement of Dopamine D1 Receptor and MEK Signaling Pathway in the Ventromedial Prefrontal Cortex in Consolidation and Reconsolidation of Recognition Memory

    Science.gov (United States)

    Maroun, Mouna; Akirav, Irit

    2009-01-01

    We investigated MEK and D1 receptors in the ventromedial prefrontal cortex (vmPFC) in consolidation and reconsolidation of recognition memory in rats nonhabituated to the experimental context (NH) or with reduced arousal due to extensive prior habituation (H). The D1 receptor antagonist enhanced consolidation and impaired reconsolidation in NH but…

  8. A new perspective on the role of the CREB family of transcription factors in memory consolidation via adult hippocampal neurogenesis

    Directory of Open Access Journals (Sweden)

    Sylvia eOrtega-Martinez

    2015-08-01

    Full Text Available Adult neurogenesis is the process by which new neurons are generated in the brains of adults. Since its discovery 50 years ago, adult neurogenesis has been widely studied in the mammalian brain and has provided a new perspective on the pathophysiology of many psychiatric and neurodegenerative disorders, some of which affect memory. In this regard, adult hippocampal neurogenesis (AHN, which occurs in the subgranular zone of the dentate gyrus, has been suggested to play a role in the formation and consolidation of new memories. This process involves many transcription factors, of which cyclic AMP-responsive element-binding protein (CREB is a well-documented one. In the developing brain, CREB regulates crucial cell stages, (e.g., proliferation, differentiation, and survival, and in the adult brain, it participates in neuronal plasticity, learning, and memory. In addition, new evidence supports the hypothesis that CREB may also participate in learning and memory through its involvement in AHN. This review examines the CREB family of transcription factors, including the different members and known signaling pathways. It highlights the role of CREB as a modulator of AHN, which could underlie its function in memory consolidation mechanisms.

  9. Basolateral amygdala activity is required for enhancement of memory consolidation produced by histone deacetylase inhibition in the hippocampus.

    Science.gov (United States)

    Blank, Martina; Dornelles, Arethuza S; Werenicz, Aline; Velho, Luciana A; Pinto, Diana F; Fedi, Ana Cláudia; Schröder, Nadja; Roesler, Rafael

    2014-05-01

    Histone acetylation, a type of chromatin modification that allows increased gene transcription and can be pharmacologically promoted by histone deacetylase (HDAC) inhibitors (HDACis), has been consistently associated with promoting memory formation in the hippocampus. The basolateral nucleus of the amygdala (BLA) is a brain area crucially involved in enabling hormones and drugs to influence memory formation. Here, we show that BLA activity is required for memory enhancement by intrahippocampal administration of an HDACi. Two different HDACis, sodium butyrate (NaB) and trichostatin A (TSA), differentially enhanced the retention of memory for inhibitory avoidance (IA) when administered to the dorsal hippocampus after training. TSA showed a biphasic pattern of response during consolidation, in which infusions given immediately or 3h after training produced memory enhancement, whereas no effect was observed when it was infused 1.5 or 6h posttraining. Muscimol (MUS)-induced unilateral functional inactivation of the BLA prevented the enhancement of memory retention produced by posttraining infusion of TSA into the ipsilateral hippocampus. TSA did not affect IA extinction or reconsolidation. These results indicate that HDACis can increase IA memory retention when given into the hippocampus, and, most importantly, BLA activity is necessary for enabling HDACi-induced influences on memory formation. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Cognitive dissonance resolution depends on episodic memory.

    Science.gov (United States)

    Chammat, Mariam; Karoui, Imen El; Allali, Sébastien; Hagège, Joshua; Lehongre, Katia; Hasboun, Dominique; Baulac, Michel; Epelbaum, Stéphane; Michon, Agnès; Dubois, Bruno; Navarro, Vincent; Salti, Moti; Naccache, Lionel

    2017-01-23

    The notion that past choices affect preferences is one of the most influential concepts of social psychology since its first report in the 50 s, and its theorization within the cognitive dissonance framework. In the free-choice paradigm (FCP) after choosing between two similarly rated items, subjects reevaluate chosen items as more attractive and rejected items as less attractive. However the relations prevailing between episodic memory and choice-induced preference change (CIPC) remain highly debated: is this phenomenon dependent or independent from memory of past choices? We solve this theoretical debate by demonstrating that CIPC occurs exclusively for items which were correctly remembered as chosen or rejected during the choice stage. We used a combination of fMRI and intra-cranial electrophysiological recordings to reveal a modulation of left hippocampus activity, a hub of episodic memory retrieval, immediately before the occurrence of CIPC during item reevaluation. Finally, we show that contrarily to a previous influential report flawed by a statistical artifact, this phenomenon is absent in amnesic patients for forgotten items. These results demonstrate the dependence of cognitive dissonance on conscious episodic memory. This link between current preferences and previous choices suggests a homeostatic function of this regulative process, aiming at preserving subjective coherence.

  11. Cognitive dissonance resolution depends on episodic memory

    Science.gov (United States)

    Chammat, Mariam; Karoui, Imen El; Allali, Sébastien; Hagège, Joshua; Lehongre, Katia; Hasboun, Dominique; Baulac, Michel; Epelbaum, Stéphane; Michon, Agnès; Dubois, Bruno; Navarro, Vincent; Salti, Moti; Naccache, Lionel

    2017-01-01

    The notion that past choices affect preferences is one of the most influential concepts of social psychology since its first report in the 50 s, and its theorization within the cognitive dissonance framework. In the free-choice paradigm (FCP) after choosing between two similarly rated items, subjects reevaluate chosen items as more attractive and rejected items as less attractive. However the relations prevailing between episodic memory and choice-induced preference change (CIPC) remain highly debated: is this phenomenon dependent or independent from memory of past choices? We solve this theoretical debate by demonstrating that CIPC occurs exclusively for items which were correctly remembered as chosen or rejected during the choice stage. We used a combination of fMRI and intra-cranial electrophysiological recordings to reveal a modulation of left hippocampus activity, a hub of episodic memory retrieval, immediately before the occurrence of CIPC during item reevaluation. Finally, we show that contrarily to a previous influential report flawed by a statistical artifact, this phenomenon is absent in amnesic patients for forgotten items. These results demonstrate the dependence of cognitive dissonance on conscious episodic memory. This link between current preferences and previous choices suggests a homeostatic function of this regulative process, aiming at preserving subjective coherence. PMID:28112261

  12. An mRNA expression analysis of stimulation and blockade of 5-HT7 receptors during memory consolidation.

    Science.gov (United States)

    Pérez-García, Georgina; Gonzalez-Espinosa, Claudia; Meneses, Alfredo

    2006-04-25

    Despite the compelling support for 5-hydroxytryptamine (5-HT) receptors participation in learning and memory in mammal species, the molecular basis had been largely absent from any discussion of its mechanistic underpinnings. Here, we report that reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that there was a higher level of expression of the investigated 5-HT receptor mRNAs in autoshaping-trained relative to untrained groups. Actually, pharmacological naïve untrained and autoshaping-trained rats showed significant differences, the latter groups expressing, in decreasing order, 5-HT1A memory consolidation, we combined selective 5-HT7 receptors stimulation or blockade in the same animals, and brain areas individually analyzed. 5-HT7 receptors were strongly expressed in all the three brain areas of vehicle-trained rats relative to untrained group. The potential selective 5-HT7 receptor agonist AS 19 enhanced memory consolidation, attenuated mRNA receptors expression, and the facilitatory memory effect was reversed by SB-269970. Finally, pharmacological stimulation of 5-HT7 receptors reversed scopolamine- or dizocilpine-induced amnesia and receptor down-regulation.

  13. Sequence specific motor performance gains after memory consolidation in children and adolescents.

    Directory of Open Access Journals (Sweden)

    Shoshi Dorfberger

    Full Text Available Memory consolidation for a trained sequence of finger opposition movements, in 9- and 12-year-old children, was recently found to be significantly less susceptible to interference by a subsequent training experience, compared to that of 17-year-olds. It was suggested that, in children, the experience of training on any sequence of finger movements may affect the performance of the sequence elements, component movements, rather than the sequence as a unit; the latter has been implicated in the learning of the task by adults. This hypothesis implied a possible childhood advantage in the ability to transfer the gains from a trained to the reversed, untrained, sequence of movements. Here we report the results of transfer tests undertaken to test this proposal in 9-, 12-, and 17-year-olds after training in the finger-to-thumb opposition sequence (FOS learning task. Our results show that the performance gains in the trained sequence partially transferred from the left, trained hand, to the untrained hand at 48-hours after a single training session in the three age-groups tested. However, there was very little transfer of the gains from the trained to the untrained, reversed, sequence performed by either hand. The results indicate sequence specific post-training gains in FOS performance, as opposed to a general improvement in performance of the individual, component, movements that comprised both the trained and untrained sequences. These results do not support the proposal that the reduced susceptibility to interference, in children before adolescence, reflects a difference in movement syntax representation after training.

  14. Memory consolidation in children with specific language impairment: Delayed gains and susceptibility to interference in implicit sequence learning.

    Science.gov (United States)

    Desmottes, Lise; Maillart, Christelle; Meulemans, Thierry

    2017-04-01

    In this study, the time course of the procedural learning of a visuomotor sequence skill was followed over a 24-hour and a 1-week time period in children with and without specific language impairment (SLI). Two aspects of memory consolidation in implicit sequence learning were examined: the evolution of post-training gains in sequence knowledge (Experiment 1) and the susceptibility to interference (Experiment 2). In the first experiment, 18 children with SLI and 17 control children matched for sex, age, and nonverbal intelligence completed a serial reaction-time (SRT) task and were tested 24 hours and 1 week after practicing. The two groups of children attained an equal level of sequence knowledge in the training session, but the children with SLI lacked the consolidation gains displayed by the control children in the two post-training sessions. Working with a new group of children, 17 with SLI and 17 control peers, Experiment 2 examined resistance to interference by introducing a second sequence 15 min after the first training session. Similar results were obtained for the performance of both groups in the training session. However, although the performance of the control group improved in the post-training sessions, the performance of the SLI group deteriorated significantly during the consolidation phase due to the interfering sequence. These findings suggest that the consolidation phase of sequence learning is impaired in children with SLI.

  15. A role for Tac2, NkB, and Nk3 receptor in normal and dysregulated fear memory consolidation.

    Science.gov (United States)

    Andero, Raül; Dias, Brian G; Ressler, Kerry J

    2014-07-16

    The centromedial amygdala (CeM), a subdivision of the central amygdala (CeA), is believed to be the main output station of the amygdala for fear expression. We provide evidence that the Tac2 gene, expressed by neurons specifically within the CeM, is required for modulating fear memories. Tac2 is colocalized with GAD65 and CaMKIIα but not with PKCd and Enk neurons in the CeM. Moreover, the Tac2 product, NkB, and its specific receptor, Nk3R, are also involved in the consolidation of fear memories. Increased Tac2 expression, through a stress-induced PTSD-like model, or following lentiviral CeA overexpression, are sufficient to enhance fear consolidation. This effect is blocked by the Nk3R antagonist osanetant. Concordantly, silencing of Tac2-expressing neurons in CeA with DREADDs impairs fear consolidation. Together, these studies further our understanding of the role of the Tac2 gene and CeM in fear processing and may provide approaches to intervention for fear-related disorders.

  16. G9a/GLP histone lysine dimethyltransferase complex activity in the hippocampus and the entorhinal cortex is required for gene activation and silencing during memory consolidation.

    Science.gov (United States)

    Gupta-Agarwal, Swati; Franklin, Aimee V; Deramus, Thomas; Wheelock, Muriah; Davis, Robin L; McMahon, Lori L; Lubin, Farah D

    2012-04-18

    Learning triggers alterations in gene transcription in brain regions such as the hippocampus and the entorhinal cortex (EC) that are necessary for long-term memory (LTM) formation. Here, we identify an essential role for the G9a/G9a-like protein (GLP) lysine dimethyltransferase complex and the histone H3 lysine 9 dimethylation (H3K9me2) marks it catalyzes, in the transcriptional regulation of genes in area CA1 of the rat hippocampus and the EC during memory consolidation. Contextual fear learning increased global levels of H3K9me2 in area CA1 and the EC, with observable changes at the Zif268, DNMT3a, BDNF exon IV, and cFOS gene promoters, which occurred in concert with mRNA expression. Inhibition of G9a/GLP in the EC, but not in the hippocampus, enhanced contextual fear conditioning relative to control animals. The inhibition of G9a/GLP in the EC induced several histone modifications that include not only methylation but also acetylation. Surprisingly, we found that downregulation of G9a/GLP activity in the EC enhanced H3K9me2 in area CA1, resulting in transcriptional silencing of the non-memory permissive gene COMT in the hippocampus. In addition, synaptic plasticity studies at two distinct EC-CA1 cellular pathways revealed that G9a/GLP activity is critical for hippocampus-dependent long-term potentiation initiated in the EC via the perforant pathway, but not the temporoammonic pathway. Together, these data demonstrate that G9a/GLP differentially regulates gene transcription in the hippocampus and the EC during memory consolidation. Furthermore, these findings support the possibility of a role for G9a/GLP in the regulation of cellular and molecular cross talk between these two brain regions during LTM formation.

  17. Decreased nocturnal growth hormone secretion and sleep fragmentation in combat-related posttraumatic stress disorder; potential predictors of impaired memory consolidation

    NARCIS (Netherlands)

    van Liempt, Saskia; Vermetten, Eric; Lentjes, Eef; Arends, Johan; Westenberg, Herman

    2011-01-01

    Background: Healthy sleep facilitates the consolidation of newly acquired memories. Although patients with posttraumatic stress disorder (PTSD) often complain of sleep disturbances and memory deficits, the interrelatedness of these symptoms is not well understood. Sleep may be disturbed in PTSD by i

  18. Glucocorticoids interact with the noradrenergic arousal system in the nucleus accumbens shell to enhance memory consolidation of both appetitive and aversive taste learning

    NARCIS (Netherlands)

    Wichmann, Romy; Fornari, Raquel V.; Roozendaal, Benno

    2012-01-01

    It is well established that glucocorticoid hormones strengthen the consolidation of long-term memory of emotionally arousing experiences but have little effect on memory of low-arousing experiences. Although both positive and negative emotionally arousing events tend to be well remembered, studies i

  19. Eye tracking, cortisol, and a sleep vs. wake consolidation delay: combining methods to uncover an interactive effect of sleep and cortisol on memory.

    Science.gov (United States)

    Bennion, Kelly A; Mickley Steinmetz, Katherine R; Kensinger, Elizabeth A; Payne, Jessica D

    2014-06-18

    Although rises in cortisol can benefit memory consolidation, as can sleep soon after encoding, there is currently a paucity of literature as to how these two factors may interact to influence consolidation. Here we present a protocol to examine the interactive influence of cortisol and sleep on memory consolidation, by combining three methods: eye tracking, salivary cortisol analysis, and behavioral memory testing across sleep and wake delays. To assess resting cortisol levels, participants gave a saliva sample before viewing negative and neutral objects within scenes. To measure overt attention, participants' eye gaze was tracked during encoding. To manipulate whether sleep occurred during the consolidation window, participants either encoded scenes in the evening, slept overnight, and took a recognition test the next morning, or encoded scenes in the morning and remained awake during a comparably long retention interval. Additional control groups were tested after a 20 min delay in the morning or evening, to control for time-of-day effects. Together, results showed that there is a direct relation between resting cortisol at encoding and subsequent memory, only following a period of sleep. Through eye tracking, it was further determined that for negative stimuli, this beneficial effect of cortisol on subsequent memory may be due to cortisol strengthening the relation between where participants look during encoding and what they are later able to remember. Overall, results obtained by a combination of these methods uncovered an interactive effect of sleep and cortisol on memory consolidation.

  20. Eye Tracking, Cortisol, and a Sleep vs. Wake Consolidation Delay: Combining Methods to Uncover an Interactive Effect of Sleep and Cortisol on Memory

    Science.gov (United States)

    Bennion, Kelly A.; Mickley Steinmetz, Katherine R.; Kensinger, Elizabeth A.; Payne, Jessica D.

    2014-01-01

    Although rises in cortisol can benefit memory consolidation, as can sleep soon after encoding, there is currently a paucity of literature as to how these two factors may interact to influence consolidation. Here we present a protocol to examine the interactive influence of cortisol and sleep on memory consolidation, by combining three methods: eye tracking, salivary cortisol analysis, and behavioral memory testing across sleep and wake delays. To assess resting cortisol levels, participants gave a saliva sample before viewing negative and neutral objects within scenes. To measure overt attention, participants’ eye gaze was tracked during encoding. To manipulate whether sleep occurred during the consolidation window, participants either encoded scenes in the evening, slept overnight, and took a recognition test the next morning, or encoded scenes in the morning and remained awake during a comparably long retention interval. Additional control groups were tested after a 20 min delay in the morning or evening, to control for time-of-day effects. Together, results showed that there is a direct relation between resting cortisol at encoding and subsequent memory, only following a period of sleep. Through eye tracking, it was further determined that for negative stimuli, this beneficial effect of cortisol on subsequent memory may be due to cortisol strengthening the relation between where participants look during encoding and what they are later able to remember. Overall, results obtained by a combination of these methods uncovered an interactive effect of sleep and cortisol on memory consolidation. PMID:24962611

  1. ONE-DIMENSIONAL CONSOLIDATION OF LAYERED SOILS WITH IMPEDED BOUNDARIES UNDER TIME- DEPENDENT LOADINGS

    Institute of Scientific and Technical Information of China (English)

    蔡袁强; 梁旭; 吴世明

    2004-01-01

    On the basis of Terzaghi's one-dimensional consolidation theory, the variation of effective stress ratio in layered saturated soils with impeded boundaries under timedependent loading was studied. By the method of Laplace transform, the solution was presented. Influences of different kinds of cyclic loadings and impeded boundaries conditions were discussed. Through numerical inversion of Laplace transform, useful illustrations were given considering several common time-dependent loadings. Pervious or impervious boundary condition is just the special case of the problem considered here. Compared with average index method, the results from the method illustrated are more accurate.

  2. Pheromone-Induced Olfactory Memory in Newborn Rabbits: Involvement of Consolidation and Reconsolidation Processes

    Science.gov (United States)

    Coureaud, Gerard; Languille, Solene; Schaal, Benoist; Hars, Bernard

    2009-01-01

    Mammary pheromone (MP)-induced odor memory is a new model of appetitive memory functioning early in a mammal, the newborn rabbit. Some properties of this associative memory are analyzed by the use of anisomycin as an amnesic agent. Long-term memory (LTM) was impaired by anisomycin delivered immediately, but not 4 h after either acquisition or…

  3. Pheromone-Induced Olfactory Memory in Newborn Rabbits: Involvement of Consolidation and Reconsolidation Processes

    Science.gov (United States)

    Coureaud, Gerard; Languille, Solene; Schaal, Benoist; Hars, Bernard

    2009-01-01

    Mammary pheromone (MP)-induced odor memory is a new model of appetitive memory functioning early in a mammal, the newborn rabbit. Some properties of this associative memory are analyzed by the use of anisomycin as an amnesic agent. Long-term memory (LTM) was impaired by anisomycin delivered immediately, but not 4 h after either acquisition or…

  4. REM Sleep-Dependent Bidirectional Regulation of Hippocampal-Based Emotional Memory and LTP.

    Science.gov (United States)

    Ravassard, Pascal; Hamieh, Al Mahdy; Joseph, Mickaël Antoine; Fraize, Nicolas; Libourel, Paul-Antoine; Lebarillier, Léa; Arthaud, Sébastien; Meissirel, Claire; Touret, Monique; Malleret, Gaël; Salin, Paul-Antoine

    2016-04-01

    Prolonged rapid-eye-movement (REM) sleep deprivation has long been used to study the role of REM sleep in learning and memory processes. However, this method potentially induces stress and fatigue that may directly affect cognitive functions. Here, by using a short-term and nonstressful REM sleep deprivation (RSD) method we assessed in rats the bidirectional influence of reduced and increased REM sleep amount on hippocampal-dependent emotional memory and plasticity. Our results indicate that 4 h RSD impaired consolidation of contextual fear conditioning (CFC) and induction of long-term potentiation (LTP), while decreasing density of Egr1/Zif268-expressing neurons in the CA1 region of the dorsal hippocampus. LTP and Egr1 expression were not affected in ventral CA1. Conversely, an increase in REM sleep restores and further facilitates CFC consolidation and LTP induction, and also increases Egr1 expression in dorsal CA1. Moreover, CFC consolidation, Egr1 neuron density, and LTP amplitude in dorsal CA1 show a positive correlation with REM sleep amount. Altogether, these results indicate that mild changes in REM sleep amount bidirectionally affect memory and synaptic plasticity mechanisms occurring in the CA1 area of the dorsal hippocampus.

  5. Infusion of methylphenidate into the basolateral nucleus of amygdala or anterior cingulate cortex enhances fear memory consolidation in rats

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The psychostimulant methylphenidate (MPD; also called Ritalin) is a blocker of dopamine and norepi-nephrine transporter. It has been clinically used for treatment of Attention Deficit and Hyperactivity Disorder (ADHD). There have been inconsistent reports regarding the effects of systemically adminis-tered MPD on learning and memory, either in animals or humans. In the present study, we investigated the effect of direct infusion of MPD into the basolateral nucleus of amygdala (BLA) or the anterior cin-gulate cortex (ACC) on conditioned fear memory. Rats were trained on a one-trial step-through inhibi-tory avoidance task. MPD was infused bilaterally into the BLA or the ACC, either at ‘0’ or 6 h post-training. Saline was administered as control. Memory retention was tested 48 h post-training. In-tra-BLA or intra-ACC infusion of MPD ‘0’ h but not 6 h post-training significantly improved 48-h memory retention: the MPD-treated rats had significant longer step-through latency than controls. The present results indicate that action of MPD in the BLA or the ACC produces a beneficial effect on the consoli-dation of inhibitory avoidance memory.

  6. Infusion of methylphenidate into the basolateral nucleus of amygdala or anterior cingulate cortex enhances fear memory consolidation in rats

    Institute of Scientific and Technical Information of China (English)

    ZHENG XinLing; LIU Fang; WU XingWen; LI BaoMing

    2008-01-01

    The psychostimulant methylphenidate (MPD; also called Ritalin) is a blocker of dopamine and norepi-nephrine transporter. It has been clinically used for treatment of Attention Deficit and Hyperactivity Disorder (ADHD). There have been inconsistent reports regarding the effects of systemically adminis-tered MPD on learning and memory, either in animals or humans. In the present study, we investigated the effect of direct infusion of MPD into the basolaterel nucleus of amygdala (BLA) or the anterior cin-gulate cortex (ACC) on conditioned fear memory. Rats were trained on a one-trial step-through inhibi-tory avoidance task. MPD was infused bilaterally into the BLA or the ACC, either at '0' or 6 h post-treining. Saline was administered as control. Memory retention was tested 48 h poet-training. In-tra-BLA or intra-ACC infusion of MPD '0' h but not 6 h post-training significantly improved 48-h memory retention: the MPD-treated rats had significant longer step-through latency than controls. The present results indicate that action of MPD in the BLA or the ACC produces a beneficial effect on the consoli-dation of inhibitory avoidance memory.

  7. [Effect of daytime nap on consolidation of declarative memory in humans].

    Science.gov (United States)

    Ukraintseva, Iu V; Dorokhov, V B

    2011-01-01

    We studied effects of a daytime nap (1 hour) with including only NREM sleep on performance of declarative memory task (60 semantically unrelated word pairs) and general functional state. During training, procedure of learning of 30 word pairs was presented once, and that of the other 30 pairs was repeated twice. Strength of the task acquisition was tested. Subjects participated in two experiments: basic and control one. After learning participants either took a nap (basic experiment) or kept awake looking movies (control experiment). In 4.5 hours after the training session all the subjects were retested. As compared to the subjects who stayed awake during the training-retesting interval, subjects who had a NREM nap demonstrated enhanced performance. Concerning the strength of task acquisition, sleep-dependent performance was observed only for the word pairs learned once. Naps did not affect the functional state assessed by the reaction time dynamics and psychological testing.

  8. Long-term memory consolidation: The role of RNA-binding proteins with prion-like domains.

    Science.gov (United States)

    Sudhakaran, Indulekha P; Ramaswami, Mani

    2016-10-11

    Long-term and short-term memories differ primarily in the duration of their retention. At a molecular level, long-term memory (LTM) is distinguished from short-term memory (STM) by its requirement for new gene expression. In addition to transcription (nuclear gene expression) the translation of stored mRNAs is necessary for LTM formation. The mechanisms and functions for temporal and spatial regulation of mRNAs required for LTM is a major contemporary problem, of interest from molecular, cell biological, neurobiological and clinical perspectives. This review discusses primary evidence in support for translational regulatory events involved in LTM and a model in which different phases of translation underlie distinct phases of consolidation of memories. However, it focuses largely on mechanisms of memory persistence and the role of prion-like domains in this defining aspect of long-term memory. We consider primary evidence for the concept that Cytoplasmic Polyadenylation Element Binding (CPEB) protein enables the persistence of formed memories by transforming in prion-like manner from a soluble monomeric state to a self-perpetuating and persistent polymeric translationally active state required for maintaining persistent synaptic plasticity. We further discuss prion-like domains prevalent on several other RNA-binding proteins involved in neuronal translational control underlying LTM. Growing evidence indicates that such RNA regulatory proteins are components of mRNP (RiboNucleoProtein) granules. In these proteins, prion-like domains, being intrinsically disordered, could mediate weak transient interactions that allow the assembly of RNP granules, a source of silenced mRNAs whose translation is necessary for LTM. We consider the structural bases for RNA granules formation as well as functions of disordered domains and discuss how these complicate the interpretation of existing experimental data relevant to general mechanisms by which prion-domain containing RBPs

  9. The critical role of sleep spindles in hippocampal-dependent memory: a pharmacology study

    OpenAIRE

    Mednick, Sara C.; McDevitt, Elizabeth A.; Walsh, James K.; Wamsley, Erin; Paulus, Martin; Kanady, Jennifer C; Sean P.A. Drummond

    2013-01-01

    An important function of sleep is the consolidation of memories, and features of sleep, such as rapid eye movement (REM) or sleep spindles, have been shown to correlate with improvements in discrete memory domains. Because of the methodological difficulties in modulating sleep, however, a causal link between specific sleep features and human memory consolidation is lacking. Here, we experimentally manipulated specific sleep features during a daytime nap via direct pharmacological intervention...

  10. Ganzfeld stimulation or sleep enhance long term motor memory consolidation compared to normal viewing in saccadic adaptation paradigm.

    Directory of Open Access Journals (Sweden)

    Caroline Voges

    Full Text Available Adaptation of saccade amplitude in response to intra-saccadic target displacement is a type of implicit motor learning which is required to compensate for physiological changes in saccade performance. Once established trials without intra-saccadic target displacement lead to de-adaptation or extinction, which has been attributed either to extra-retinal mechanisms of spatial constancy or to the influence of the stable visual surroundings. Therefore we investigated whether visual deprivation ("Ganzfeld"-stimulation or sleep can partially maintain this motor learning compared to free viewing of the natural surroundings. Thirty-five healthy volunteers performed two adaptation blocks of 100 inward adaptation trials - interspersed by an extinction block - which were followed by a two-hour break with or without visual deprivation (VD. Using additional adaptation and extinction blocks short and long (4 weeks term memory of this implicit motor learning were tested. In the short term, motor memory tested immediately after free viewing was superior to adaptation performance after VD. In the long run, however, effects were opposite: motor memory and relearning of adaptation was superior in the VD conditions. This could imply independent mechanisms that underlie the short-term ability of retrieving learned saccadic gain and its long term consolidation. We suggest that subjects mainly rely on visual cues (i.e., retinal error in the free viewing condition which makes them prone to changes of the visual stimulus in the extinction block. This indicates the role of a stable visual array for resetting adapted saccade amplitudes. In contrast, visual deprivation (GS and sleep, might train subjects to rely on extra-retinal cues, e.g., efference copy or prediction to remap their internal representations of saccade targets, thus leading to better consolidation of saccadic adaptation.

  11. Resistance exercise improves hippocampus-dependent memory

    Directory of Open Access Journals (Sweden)

    R.C. Cassilhas

    2012-12-01

    Full Text Available It has been demonstrated that resistance exercise improves cognitive functions in humans. Thus, an animal model that mimics this phenomenon can be an important tool for studying the underlying neurophysiological mechanisms. Here, we tested if an animal model for resistance exercise was able to improve the performance in a hippocampus-dependent memory task. In addition, we also evaluated the level of insulin-like growth factor 1/insulin growth factor receptor (IGF-1/IGF-1R, which plays pleiotropic roles in the nervous system. Adult male Wistar rats were divided into three groups (N = 10 for each group: control, SHAM, and resistance exercise (RES. The RES group was submitted to 8 weeks of progressive resistance exercise in a vertical ladder apparatus, while the SHAM group was left in the same apparatus without exercising. Analysis of a cross-sectional area of the flexor digitorum longus muscle indicated that this training period was sufficient to cause muscle fiber hypertrophy. In a step-through passive avoidance task (PA, the RES group presented a longer latency than the other groups on the test day. We also observed an increase of 43 and 94% for systemic and hippocampal IGF-1 concentration, respectively, in the RES group compared to the others. A positive correlation was established between PA performance and systemic IGF-1 (r = 0.46, P < 0.05. Taken together, our data indicate that resistance exercise improves the hippocampus-dependent memory task with a concomitant increase of IGF-1 level in the rat model. This model can be further explored to better understand the effects of resistance exercise on brain functions.

  12. The timing of learning before night-time sleep differentially affects declarative and procedural long-term memory consolidation in adolescents.

    Directory of Open Access Journals (Sweden)

    Johannes Holz

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

  13. The timing of learning before night-time sleep differentially affects declarative and procedural long-term memory consolidation in adolescents.

    Science.gov (United States)

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

    2012-01-01

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

  14. TrkB blockade in the hippocampus after training or retrieval impairs memory: protection from consolidation impairment by histone deacetylase inhibition.

    Science.gov (United States)

    Blank, Martina; Petry, Fernanda S; Lichtenfels, Martina; Valiati, Fernanda E; Dornelles, Arethuza S; Roesler, Rafael

    2016-03-01

    Relatively little is known about the requirement of signaling initiated by brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin receptor kinase B (TrkB), in the early phases of memory consolidation, as well as about its possible functional interactions with epigenetic mechanisms. Here we show that blocking TrkB in the dorsal hippocampus after learning or retrieval impairs retention of memory for inhibitory avoidance (IA). More importantly, the impairing effect of TrkB antagonism on consolidation was completely prevented by the histone deacetylase (HDAC) inhibitor sodium butyrate (NaB). Male Wistar rats were given an intrahippocampal infusion of saline (SAL) or NaB before training, followed by an infusion of either vehicle (VEH) or the selective TrkB antagonist ANA-12 immediately after training. In a second experiment, the infusions were administered before and after retrieval. ANA-12 after either training or retrieval produced a significant impairment in a subsequent memory retention test. Pretraining administration of NaB prevented the effect of ANA-12, although NaB given before retrieval did not alter the impairment resulting from TrkB blockade. The results indicate that inhibition of BDNF/TrkB in the hippocampus can hinder consolidation and reconsolidation of IA memory. However, TrkB activity is not required for consolidation in the presence of NaB, suggesting that a dysfunction in BDNF/TrkB signaling can be fully compensated by HDAC inhibition to allow hippocampal memory formation.

  15. Short-term memory formation and long-term memory consolidation are enhanced by cellular prion association to stress-inducible protein 1.

    Science.gov (United States)

    Coitinho, Adriana S; Lopes, Marilene H; Hajj, Glaucia N M; Rossato, Janine I; Freitas, Adriana R; Castro, Cibele C; Cammarota, Martin; Brentani, Ricardo R; Izquierdo, Ivan; Martins, Vilma R

    2007-04-01

    Cellular prion protein (PrP(C)) is a cell surface glycoprotein that interacts with several ligands such as laminin, NCAM (Neural-Cell Adhesion Molecule) and the stress-inducible protein 1 (STI1). PrP(C) association with these proteins in neurons mediates adhesion, differentiation and protection against programmed cell death. Herein, we used an aversively motivated learning paradigm in rats to investigate whether STI1 interaction with PrP(C) affects short-term memory (STM) formation and long-term memory (LTM) consolidation. Blockage of PrP(C)-STI1 interaction with intra-hippocampal infusion of antibodies against PrP(C) or STI1 immediately after training impaired both STM and LTM. Furthermore, infusion of PrP(C) peptide 106-126, which competes for PrP(C)-STI1 interaction, also inhibited both forms of memory. Remarkably, STI1 peptide 230-245, which includes the PrP(C) binding site, had a potent enhancing effect on memory performance, which could be blocked by co-treatment with the competitive PrP(C) peptide 106-126. Taken together, these results demonstrate that PrP(C)-STI1 interaction modulates both STM and LTM and suggests a potential use of ST11 peptide 230-245 as a pharmacological agent.

  16. Sevoflurane Inhalation Accelerates the Long-Term Memory Consolidation via Small GTPase Overexpression in the Hippocampus of Mice in Adolescence.

    Science.gov (United States)

    Nakamura, Emi; Kinoshita, Hiroyuki; Feng, Guo-Gang; Hayashi, Hisaki; Satomoto, Maiko; Sato, Motohiko; Fujiwara, Yoshihiro

    2016-01-01

    Sevoflurane exposure impairs the long-term memory in neonates. Whether the exposure to animals in adolescence affects the memory, however, has been unclear. A small hydrolase enzyme of guanosine triphosphate (GTPase) rac1 plays a role in the F-actin dynamics related to the synaptic plasticity, as well as superoxide production via reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation. The current study was designed to examine whether sevoflurane exposure to mice in early adolescence modifies the long-term learning ability concomitantly with the changes in F-actin constitution as well as superoxide production in the hippocampus according to the levels of rac1 protein expression. Four-week-old mice were subjected to the evaluation of long-term learning ability for three days. On day one, each mouse was allowed to enter a dark chamber for five min to acclimatization. On day two, the procedure was repeated with the addition of an electric shock as soon as a mouse entered the dark chamber. All mice subsequently inhaled 2 L/min air with (Sevoflurane group) and without (Control group) 2.5% sevoflurane for three hours. On day three, each mouse was placed on the platform and retention time, which is the latency to enter the dark chamber, was examined. The brain removed after the behavior test, was used for analyses of immunofluorescence, Western immunoblotting and intracellular levels of superoxide. Sevoflurane exposure significantly prolonged retention time, indicating the enhanced long-term memory. Sevoflurane inhalation augmented F-actin constitution coexisting with the rac1 protein overexpression in the hippocampus whereas it did not alter the levels of superoxide. Sevoflurane exposure to 4-week-old mice accelerates the long-term memory concomitantly with the enhanced F-actin constitution coexisting with the small GTPase rac1 overexpression in the hippocampus. These results suggest that sevoflurane inhalation may amplify long-term memory

  17. Posterior parietal cortex is critical for the encoding, consolidation, and retrieval of a memory that guides attention for learning.

    Science.gov (United States)

    Schiffino, Felipe L; Zhou, Vivian; Holland, Peter C

    2014-02-01

    Within most contemporary learning theories, reinforcement prediction error, the difference between the obtained and expected reinforcer value, critically influences associative learning. In some theories, this prediction error determines the momentary effectiveness of the reinforcer itself, such that the same physical event produces more learning when its presentation is surprising than when it is expected. In other theories, prediction error enhances attention to potential cues for that reinforcer by adjusting cue-specific associability parameters, biasing the processing of those stimuli so that they more readily enter into new associations in the future. A unique feature of these latter theories is that such alterations in stimulus associability must be represented in memory in an enduring fashion. Indeed, considerable data indicate that altered associability may be expressed days after its induction. Previous research from our laboratory identified brain circuit elements critical to the enhancement of stimulus associability by the omission of an expected event, and to the subsequent expression of that altered associability in more rapid learning. Here, for the first time, we identified a brain region, the posterior parietal cortex, as a potential site for a memorial representation of altered stimulus associability. In three experiments using rats and a serial prediction task, we found that intact posterior parietal cortex function was essential during the encoding, consolidation, and retrieval of an associability memory enhanced by surprising omissions. We discuss these new results in the context of our previous findings and additional plausible frontoparietal and subcortical networks.

  18. Late protein synthesis-dependent phases in CTA long-term memory: BDNF requirement

    Directory of Open Access Journals (Sweden)

    Araceli eMartínez-Moreno

    2011-09-01

    Full Text Available It has been proposed that long-term memory persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related long-term memory when protein synthesis was inhibited. Our previous studies on the insular cortex (IC, a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA, have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis dependent in different time-windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 hours after acquisition. Then, we explore the effect of BDNF delivery (2 μg/2 μl per side in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes.

  19. Increased cortico-striatal connectivity during motor practice contributes to the consolidation of motor memory in writer's cramp patients

    Directory of Open Access Journals (Sweden)

    C. Gallea

    2015-01-01

    Full Text Available Sensorimotor representations of movements are created in the sensorimotor network through repeated practice to support successful and effortless performance. Writer's cramp (WC is a disorder acquired through extensive practice of finger movements, and it is likely associated with the abnormal acquisition of sensorimotor representations. We investigated (i the activation and connectivity changes in the brain network supporting the acquisition of sensorimotor representations of finger sequences in patients with WC and (ii the link between these changes and consolidation of motor performance 24 h after the initial practice. Twenty-two patients with WC and 22 age-matched healthy volunteers practiced a complex sequence with the right (pathological hand during functional MRI recording. Speed and accuracy were measured immediately before and after practice (day 1 and 24 h after practice (day 2. The two groups reached equivalent motor performance on day 1 and day 2. During motor practice, patients with WC had (i reduced hippocampal activation and hippocampal–striatal functional connectivity; and (ii overactivation of premotor–striatal areas, whose connectivity correlated with motor performance after consolidation. These results suggest that patients with WC use alternative networks to reach equiperformance in the acquisition of new motor memories.

  20. REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity

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    Médhi Gilson

    2015-12-01

    Full Text Available Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24 listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min morning nap. The other half had a long (90 min morning nap, richer in REM and N2 sleep. Story recall, mood evolution and changes in emotional response to the re-exposure to the story were assessed after the nap. Although recall performance was similar for sad and neutral stories irrespective of nap duration, sleep measures were correlated with recall performance in the sad story condition only. After the long nap, REM sleep density positively correlated with retrieval performance, while re-exposure to the sad story led to diminished mood and increased skin conductance levels. Our results suggest that REM sleep may not only be associated with the consolidation of intrinsically sad material, but also enhances mood reactivity, at least on the short term.

  1. REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity.

    Science.gov (United States)

    Gilson, Médhi; Deliens, Gaétane; Leproult, Rachel; Bodart, Alice; Nonclercq, Antoine; Ercek, Rudy; Peigneux, Philippe

    2015-12-29

    Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM) sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24) listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min) morning nap. The other half had a long (90 min) morning nap, richer in REM and N2 sleep. Story recall, mood evolution and changes in emotional response to the re-exposure to the story were assessed after the nap. Although recall performance was similar for sad and neutral stories irrespective of nap duration, sleep measures were correlated with recall performance in the sad story condition only. After the long nap, REM sleep density positively correlated with retrieval performance, while re-exposure to the sad story led to diminished mood and increased skin conductance levels. Our results suggest that REM sleep may not only be associated with the consolidation of intrinsically sad material, but also enhances mood reactivity, at least on the short term.

  2. When and Where in Skill Memory Consolidation: Neuro-Behavioral Constraints on the Acquisition and Generation of Procedural Knowledge

    Directory of Open Access Journals (Sweden)

    Korman Maria

    2011-12-01

    Full Text Available Compelling behavioral and neuro-imaging data suggest that the retention and perfection of skills (procedural, “how to” knowledge reflects long-lasting experience-driven changes in the brain’s organization (neural plasticity. Two corollaries require consideration in designing effective skill learning programs. i Neuro-behavioral constraints, imposed on whether neuronal plasticity is triggered and allowed to proceed, must be satisfied; otherwise, the skill may fail to consolidate into long-term memory. These include the amount of task iterations afforded, task scheduling, behavioral relevancy and the degree of consistency of the to-be-learned experience over a required timewindow. ii The performance of a given task reflects qualitatively different task solution routines in different phases of experience. Practice, given time and sometimes time-in-sleep, can trigger processes whereby new procedural knowledge and qualitative changes in task solution, emerge and consolidate. These emerging changes in procedural knowledge result in differences in the ability to transfer gains, across stimulus, context and task parameters.

  3. The Effect of Acute Exercise on Consolidation and Retention of Motor Memory

    DEFF Research Database (Denmark)

    Skriver, Kasper Christen

    There is substantial evidence that a single bout of exercise can improve cognitive functions and retention of certain types of declarative memory. However, it is unclear if a similar effect can be demonstrated when coupling physical activity with the acquisition and retention of a motor skill....... Hence, the overall aim of the present thesis was to investigate the relationship between acute exercise and motor memory, with special interest in investigating if exercise performed after motor skill learning could improve skill retention. Study I was designed to assess if a single bout of exercise...... improvement of long-term motor memory as running. With Study III we explored the potential mediators of the observed behavioral effect of exercise on motor memory reported in Study I. Blood samples were drawn from subjects from PRE and CON groups at various time points before, during and after motor practice...

  4. Role of signal transduction crosstalk between adenylyl cyclase and MAP kinase in hippocampus-dependent memory.

    Science.gov (United States)

    Xia, Zhengui; Storm, Daniel R

    2012-08-16

    One of the intriguing questions in neurobiology is how long-term memory (LTM) traces are established and maintained in the brain. Memory can be divided into at least two temporally and mechanistically distinct forms. Short-term memory (STM) lasts no longer than several hours, while LTM persists for days or longer. A crucial step in the generation of LTM is consolidation, a process in which STM is converted to LTM. Hippocampus-dependent LTM depends on activation of Ca(2+), Erk/MAP kinase (MAPK), and cAMP signaling pathways, as well as de novo gene expression and translation. One of the transcriptional pathways strongly implicated in LTM is the CREB/CRE (calcium, cAMP response element) transcriptional pathway. Interestingly, this transcriptional pathway may also contribute to other forms of neuroplasticity including adaptive responses to drugs. Evidence discussed in this review indicates that activation of the Erk1/2 MAP Kinase (MAPK)/CRE transcriptional pathway during the formation of hippocampus-dependent memory depends on calmodulin (CaM)-stimulated adenylyl cyclases.

  5. Effect of histamine H1 and H2 receptor antagonists, microinjected into cerebellar vermis, on emotional memory consolidation in mice

    Directory of Open Access Journals (Sweden)

    A.C.L. Gianlorenco

    2014-02-01

    Full Text Available This study investigated the effects of histamine H1 or H2 receptor antagonists on emotional memory consolidation in mice submitted to the elevated plus maze (EPM. The cerebellar vermis of male mice (Swiss albino was implanted using a cannula guide. Three days after recovery, behavioral tests were performed in the EPM on 2 consecutive days (T1 and T2. Immediately after exposure to the EPM (T1, animals received a microinjection of saline (SAL or the H1 antagonist chlorpheniramine (CPA; 0.016, 0.052, or 0.16 nmol/0.1 µL in Experiment 1, and SAL or the H2 antagonist ranitidine (RA; 0.57, 2.85, or 5.7 nmol/0.1 µL in Experiment 2. Twenty-four hours later, mice were reexposed to the EPM (T2 under the same experimental conditions but they did not receive any injection. Data were analyzed using one-way ANOVA and the Duncan test. In Experiment 1, mice microinjected with SAL and with CPA entered the open arms less often (%OAE and spent less time in the open arms (%OAT in T2, and there was no difference among groups. The results of Experiment 2 demonstrated that the values of %OAE and %OAT in T2 were lower compared to T1 for the groups that were microinjected with SAL and 2.85 nmol/0.1 µL RA. However, when animals were microinjected with 5.7 nmol/0.1 µL RA, they did not show a reduction in %OAE and %OAT. These results demonstrate that CPA did not affect behavior at the doses used in this study, while 5.7 nmol/0.1 µL RA induced impairment of memory consolidation in the EPM.

  6. Effect of histamine H1 and H2 receptor antagonists, microinjected into cerebellar vermis, on emotional memory consolidation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Gianlorenço, A.C.L.; Serafim, K.R. [Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brasil, Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Canto-de-Souza, A. [Laboratório de Psicologia da Aprendizagem, Departamento de Psicologia, Centro de Educação e Ciências Humanas, Universidade Federal de São Carlos, São Carlos, SP, Brasil, Laboratório de Psicologia da Aprendizagem, Departamento de Psicologia, Centro de Educação e Ciências Humanas, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos, São Carlos, SP, Brasil, Programa de Pós-Graduação em Ciências Fisiológicas, Universidade Federal de São Carlos, São Carlos, SP (Brazil); Instituto de Neurociências e Comportamento, Universidade de São Paulo, Ribeirão Preto, SP, Brasil, Instituto de Neurociências e Comportamento, Universidade de São Paulo, Ribeirão Preto, SP (Brazil); Mattioli, R. [Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brasil, Laboratório de Neurociências, Departamento de Fisioterapia, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP (Brazil)

    2014-02-17

    This study investigated the effects of histamine H1 or H2 receptor antagonists on emotional memory consolidation in mice submitted to the elevated plus maze (EPM). The cerebellar vermis of male mice (Swiss albino) was implanted using a cannula guide. Three days after recovery, behavioral tests were performed in the EPM on 2 consecutive days (T1 and T2). Immediately after exposure to the EPM (T1), animals received a microinjection of saline (SAL) or the H1 antagonist chlorpheniramine (CPA; 0.016, 0.052, or 0.16 nmol/0.1 µL) in Experiment 1, and SAL or the H2 antagonist ranitidine (RA; 0.57, 2.85, or 5.7 nmol/0.1 µL) in Experiment 2. Twenty-four hours later, mice were reexposed to the EPM (T2) under the same experimental conditions but they did not receive any injection. Data were analyzed using one-way ANOVA and the Duncan test. In Experiment 1, mice microinjected with SAL and with CPA entered the open arms less often (%OAE) and spent less time in the open arms (%OAT) in T2, and there was no difference among groups. The results of Experiment 2 demonstrated that the values of %OAE and %OAT in T2 were lower compared to T1 for the groups that were microinjected with SAL and 2.85 nmol/0.1 µL RA. However, when animals were microinjected with 5.7 nmol/0.1 µL RA, they did not show a reduction in %OAE and %OAT. These results demonstrate that CPA did not affect behavior at the doses used in this study, while 5.7 nmol/0.1 µL RA induced impairment of memory consolidation in the EPM.

  7. Effect of histamine H1 and H2 receptor antagonists, microinjected into cerebellar vermis, on emotional memory consolidation in mice.

    Science.gov (United States)

    Gianlorenço, A C L; Serafim, K R; Canto-de-Souza, A; Mattioli, R

    2014-02-01

    This study investigated the effects of histamine H1 or H2 receptor antagonists on emotional memory consolidation in mice submitted to the elevated plus maze (EPM). The cerebellar vermis of male mice (Swiss albino) was implanted using a cannula guide. Three days after recovery, behavioral tests were performed in the EPM on 2 consecutive days (T1 and T2). Immediately after exposure to the EPM (T1), animals received a microinjection of saline (SAL) or the H1 antagonist chlorpheniramine (CPA; 0.016, 0.052, or 0.16 nmol/0.1 µL) in Experiment 1, and SAL or the H2 antagonist ranitidine (RA; 0.57, 2.85, or 5.7 nmol/0.1 µL) in Experiment 2. Twenty-four hours later, mice were reexposed to the EPM (T2) under the same experimental conditions but they did not receive any injection. Data were analyzed using one-way ANOVA and the Duncan test. In Experiment 1, mice microinjected with SAL and with CPA entered the open arms less often (%OAE) and spent less time in the open arms (%OAT) in T2, and there was no difference among groups. The results of Experiment 2 demonstrated that the values of %OAE and %OAT in T2 were lower compared to T1 for the groups that were microinjected with SAL and 2.85 nmol/0.1 µL RA. However, when animals were microinjected with 5.7 nmol/0.1 µL RA, they did not show a reduction in %OAE and %OAT. These results demonstrate that CPA did not affect behavior at the doses used in this study, while 5.7 nmol/0.1 µL RA induced impairment of memory consolidation in the EPM.

  8. Characterization of the beta amyloid precursor protein-like gene in the central nervous system of the crab Chasmagnathus. Expression during memory consolidation

    Directory of Open Access Journals (Sweden)

    Fustiñana Maria

    2010-09-01

    Full Text Available Abstract Background Human β-amyloid, the main component in the neuritic plaques found in patients with Alzheimer's disease, is generated by cleavage of the β-amyloid precursor protein. Beyond the role in pathology, members of this protein family are synaptic proteins and have been associated with synaptogenesis, neuronal plasticity and memory, both in vertebrates and in invertebrates. Consolidation is necessary to convert a short-term labile memory to a long-term and stable form. During consolidation, gene expression and de novo protein synthesis are regulated in order to produce key proteins for the maintenance of plastic changes produced during the acquisition of new information. Results Here we partially cloned and sequenced the beta-amyloid precursor protein like gene homologue in the crab Chasmagnathus (cappl, showing a 37% of identity with the fruit fly Drosophila melanogaster homologue and 23% with Homo sapiens but with much higher degree of sequence similarity in certain regions. We observed a wide distribution of cappl mRNA in the nervous system as well as in muscle and gills. The protein localized in all tissues analyzed with the exception of muscle. Immunofluorescence revealed localization of cAPPL in associative and sensory brain areas. We studied gene and protein expression during long-term memory consolidation using a well characterized memory model: the context-signal associative memory in this crab species. mRNA levels varied at different time points during long-term memory consolidation and correlated with cAPPL protein levels Conclusions cAPPL mRNA and protein is widely distributed in the central nervous system of the crab and the time course of expression suggests a role of cAPPL during long-term memory formation.

  9. Expression of the 5-HT receptors in rat brain during memory consolidation.

    Science.gov (United States)

    Meneses, A; Manuel-Apolinar, L; Rocha, L; Castillo, E; Castillo, C

    2004-07-09

    Serotonin (5-hydroxytryptamine, 5-HT) system displays more than 14 receptors subtypes on brain areas involved in learning and memory processes, and pharmacological manipulation of specific receptors selectively affects memory formation. In order to begin the search of 5-HT receptors expression during memory formation, in this work, we aimed to determine, by autoradiography (using 3H 5-HT as ligand, 2 nM, specific activity 123 Ci/mmol), 5-HT receptors (5-HTR) expression in passive (untrained) and autoshaping trained (3 sessions) adult (3 months) and old (9 months) male rats. Thus, trained adult rats had better retention than old animals. Raphe nuclei of adult and old trained rats expressed less receptors on medial and dorsal, respectively. Hippocampal CA1 area and dentate gyrus of adult trained rats expressed less 5-HTR, while dentate gyrus of old increased them. Basomedial amygdaloid nucleus in old trained rats expressed more 5-HTR; while in the basolateral amygdaloid nucleus they were augmented in both groups. Training decreased or did not change 5-HTR in caudate-putamen of adult or old animals. The above profile of 5-HTR expression is consistent with previous reports, and suggests that memory formation and aging modulates 5-HTR expression in brain areas relevant to memory systems.

  10. Late Protein Synthesis-Dependent Phases in CTA Long-Term Memory: BDNF Requirement

    Science.gov (United States)

    Martínez-Moreno, Araceli; Rodríguez-Durán, Luis F.; Escobar, Martha L.

    2011-01-01

    It has been proposed that long-term memory (LTM) persistence requires a late protein synthesis-dependent phase, even many hours after memory acquisition. Brain-derived neurotrophic factor (BDNF) is an essential protein synthesis product that has emerged as one of the most potent molecular mediators for long-term synaptic plasticity. Studies in the rat hippocampus have been shown that BDNF is capable to rescue the late-phase of long-term potentiation as well as the hippocampus-related LTM when protein synthesis was inhibited. Our previous studies on the insular cortex (IC), a region of the temporal cortex implicated in the acquisition and storage of conditioned taste aversion (CTA), have demonstrated that intracortical delivery of BDNF reverses the deficit in CTA memory caused by the inhibition of IC protein synthesis due to anisomycin administration during early acquisition. In this work, we first analyze whether CTA memory storage is protein synthesis-dependent in different time windows. We observed that CTA memory become sensible to protein synthesis inhibition 5 and 7 h after acquisition. Then, we explore the effect of BDNF delivery (2 μg/2 μl per side) in the IC during those late protein synthesis-dependent phases. Our results show that BDNF reverses the CTA memory deficit produced by protein synthesis inhibition in both phases. These findings support the notion that recurrent rounds of consolidation-like events take place in the neocortex for maintenance of CTA memory trace and that BDNF is an essential component of these processes. PMID:21960964

  11. Influence of acute or chronic calcium channel antagonists on the acquisition and consolidation of memory and nicotine-induced cognitive effects in mice.

    Science.gov (United States)

    Biala, Grazyna; Kruk-Slomka, Marta; Jozwiak, Krzysztof

    2013-07-01

    Nicotinic cholinergic receptors (nAChRs) form a heterogeneous family of ligand-gated ion channels found in the nervous system. The main objective of our research was to investigate the interaction between cholinergic nicotinic system and calcium homeostasis in cognitive processes using the modified elevated plus maze memory model in mice. The time each mouse took to move from the open arm to either of the enclosed arms on the retention trial (transfer latency, TL2) was used as an index of memory. Our results showed that a single injection of nicotine (0.035 and 0.175 mg/kg) shortened TL2 values, improving memory-related processes. Similarly, L-type calcium channel antagonists (CCAs), i.e., flunarizine, verapamil, amlodipine, nimodipine, nifedipine, and nicardipine (at the range of dose 5-20 mg/kg) administered before or after training, decreased TL2 value improving memory acquisition and/or consolidation. Interestingly, at the subthresold doses, flunarizine, nicardipine, amlodipine, verapamil, and bupropion, a nAChR antagonist, significantly reversed the nicotine improvement of memory acquisition, while flunarizine, verapamil, and bupropion attenuated the improvement of memory consolidation provoked by an acute injection of nicotine (0.035 mg/kg, s.c.). After subchronic administration (14 days, i.p.) of verapamil and amlodipine, two CCAs with the highest affinity for nAChRs, only verapamil (5 mg/kg) impaired memory acquisition and consolidation while both verapamil and amlodipine, at the subthresold, ineffective dose (2.5 mg/kg), significantly reversed the improvement of memory provoked by an acute injection of nicotine (0.035 mg/kg, s.c.). Our findings can be useful to better understand the interaction between cholinergic nicotinic receptors and calcium-related mechanisms in memory-related processes.

  12. Statistical learning leads to persistent memory: Evidence for one-year consolidation.

    Science.gov (United States)

    Kóbor, Andrea; Janacsek, Karolina; Takács, Ádám; Nemeth, Dezso

    2017-04-10

    Statistical learning is a robust mechanism of the brain that enables the extraction of environmental patterns, which is crucial in perceptual and cognitive domains. However, the dynamical change of processes underlying long-term statistical memory formation has not been tested in an appropriately controlled design. Here we show that a memory trace acquired by statistical learning is resistant to inference as well as to forgetting after one year. Participants performed a statistical learning task and were retested one year later without further practice. The acquired statistical knowledge was resistant to interference, since after one year, participants showed similar memory performance on the previously practiced statistical structure after being tested with a new statistical structure. These results could be key to understand the stability of long-term statistical knowledge.

  13. Modifications of 5-HT4 receptor expression in rat brain during memory consolidation.

    Science.gov (United States)

    Manuel-Apolinar, L; Rocha, L; Pascoe, D; Castillo, E; Castillo, C; Meneses, A

    2005-04-25

    Pharmacological evidence indicates a specific role of 5-HT(4) receptors on memory function. These receptors are members of G-protein-coupled 7-transmembrane domain receptor superfamily, are positively coupled to adenylyl cyclase, and are heterogeneously located in some structures important for memory, such as the hippocampus and cortical regions. To further clarify 5-HT(4) receptors' role in memory, the expression of these receptors in passive (P3) untrained and autoshaping (A3) trained (3 sessions) adult (3 months) and old (P9 or A9; 9 months) male rats was determined by autoradiography. Adult trained (A3) rats showed a better memory respect to old trained (A9). Using [(3)H] GR113808 as ligand (0.2 nM specific activity 81 Ci/mmol) for 5-HT(4) receptor expression, 29 brain areas were analyzed, 16 areas of A3 and 17 of A9 animals displayed significant changes. The medial mammillary nucleus of A3 group showed diminished 5-HT(4) receptor expression, and in other 15 brain areas of A3 or 10 of A9 animals, 5-HT(4) receptors were increased. Thus, for A3 rats, 5-HT(4) receptors were augmented in olfactory lobule, caudate putamen, fundus striatum, CA2, retrosplenial, frontal, temporal, occipital, and cingulate cortex. Also, 5-HT(4) receptors were increased in olfactory tubercule, hippocampal CA1, parietal, piriform, and cingulate cortex of A9. However, hippocampal CA2 and CA3 areas, and frontal, parietal, and temporal cortex of A9 rats, expressed less 5-HT(4) receptors. These findings suggest that serotonergic activity, via 5-HT(4) receptors in hippocampal, striatum, and cortical areas, mediates memory function and provides further evidence for a complex and regionally specific regulation over 5-HT receptor expression during memory formation.

  14. The Effect of Acute Exercise on Consolidation and Retention of Motor Memory

    DEFF Research Database (Denmark)

    Skriver, Kasper Christen

    . Hence, the overall aim of the present thesis was to investigate the relationship between acute exercise and motor memory, with special interest in investigating if exercise performed after motor skill learning could improve skill retention. Study I was designed to assess if a single bout of exercise...... with the perspective of exploring the arguments for applying exercise systematically in the educational system. In addition, since a team sport could be more motivating to school children compared to e.g. running, we investigated the effects of both hockey and running on motor memory. Seventy-seven pre...

  15. The temporal locus of the interaction between working memory consolidation and the attentional blink

    NARCIS (Netherlands)

    Akyürek, E.G.; Leszczyński, Marcin; Schubö, Anna

    2010-01-01

    An increase in concurrent working memory load has been shown to amplify the attentional blink. The present study investigated the temporal locus of this phenomenon, by using a dual rapid serial visual presentation paradigm that enabled the measurement of lateralized event-related potentials. The P3

  16. The Cannabinoid System in the Retrosplenial Cortex Modulates Fear Memory Consolidation, Reconsolidation, and Extinction

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Crestani, Ana Paula; Quillfeldt, Jorge Alberto; e Souza, Tadeu Mello; de Oliveira Alvares, Lucas

    2015-01-01

    Despite the fact that the cannabinoid receptor type 1 (CB1R) plays a pivotal role in emotional memory processing in different regions of the brain, its function in the retrosplenial cortex (RSC) remains unknown. Here, using contextual fear conditioning in rats, we showed that a post-training intra-RSC infusion of the CB1R antagonist AM251…

  17. New Insights on Retrieval-Induced and Ongoing Memory Consolidation: Lessons from Arc

    Directory of Open Access Journals (Sweden)

    Jean-Pascal Morin

    2015-01-01

    Full Text Available The mainstream view on the neurobiological mechanisms underlying memory formation states that memory traces reside on the network of cells activated during initial acquisition that becomes active again upon retrieval (reactivation. These activation and reactivation processes have been called “conjunctive trace.” This process implies that singular molecular events must occur during acquisition, strengthening the connection between the implicated cells whose synchronous activity must underlie subsequent reactivations. The strongest experimental support for the conjunctive trace model comes from the study of immediate early genes such as c-fos, zif268, and activity-regulated cytoskeletal-associated protein. The expressions of these genes are reliably induced by behaviorally relevant neuronal activity and their products often play a central role in long-term memory formation. In this review, we propose that the peculiar characteristics of Arc protein, such as its optimal expression after ongoing experience or familiar behavior, together with its versatile and central functions in synaptic plasticity could explain how familiarization and recognition memories are stored and preserved in the mammalian brain.

  18. Foreground Contextual Fear Memory Consolidation Requires Two Independent Phases of Hippocampal ERK/CREB Activation

    Science.gov (United States)

    Trifilieff, Pierre; Vanhoutte, Peter; Caboche, Jocelyne; Desmedt, Aline; Riedel, Gernot; Mons, Nicole; Micheau, Jacques; Herry, Cyril

    2006-01-01

    Fear conditioning is a popular model for investigating physiological and cellular mechanisms of memory formation. In this paradigm, a footshock is either systematically associated to a tone (paired conditioning) or is pseudorandomly distributed (unpaired conditioning). In the former procedure, the tone/shock association is acquired, whereas in the…

  19. Time-resolved neuroimaging of visual short term memory consolidation by post-perceptual attention shifts.

    Science.gov (United States)

    Hecht, Marcus; Thiemann, Ulf; Freitag, Christine M; Bender, Stephan

    2016-01-15

    Post-perceptual cues can enhance visual short term memory encoding even after the offset of the visual stimulus. However, both the mechanisms by which the sensory stimulus characteristics are buffered as well as the mechanisms by which post-perceptual selective attention enhances short term memory encoding remain unclear. We analyzed late post-perceptual event-related potentials (ERPs) in visual change detection tasks (100ms stimulus duration) by high-resolution ERP analysis to elucidate these mechanisms. The effects of early and late auditory post-cues (300ms or 850ms after visual stimulus onset) as well as the effects of a visual interference stimulus were examined in 27 healthy right-handed adults. Focusing attention with post-perceptual cues at both latencies significantly improved memory performance, i.e. sensory stimulus characteristics were available for up to 850ms after stimulus presentation. Passive watching of the visual stimuli without auditory cue presentation evoked a slow negative wave (N700) over occipito-temporal visual areas. N700 was strongly reduced by a visual interference stimulus which impeded memory maintenance. In contrast, contralateral delay activity (CDA) still developed in this condition after the application of auditory post-cues and was thereby dissociated from N700. CDA and N700 seem to represent two different processes involved in short term memory encoding. While N700 could reflect visual post processing by automatic attention attraction, CDA may reflect the top-down process of searching selectively for the required information through post-perceptual attention. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Requirement of NF-kappa B Activation in Different Mice Brain Areas during Long-Term Memory Consolidation in Two Contextual One-Trial Tasks with Opposing Valences

    Science.gov (United States)

    Salles, Angeles; Krawczyk, Maria del C.; Blake, Mariano; Romano, Arturo; Boccia, Mariano M.; Freudenthal, Ramiro

    2017-01-01

    NF-kappa B is a transcription factor whose activation has been shown to be necessary for long-term memory consolidation in several species. NF-kappa B is activated and translocates to the nucleus of cells in a specific temporal window during consolidation. Our work focuses on a one trial learning tasks associated to the inhibitory avoidance (IA) setting. Mice were trained either receiving or not a footshock when entering a dark compartment (aversive vs. appetitive learning). Regardless of training condition (appetitive or aversive), latencies to step-through during testing were significantly different to those measured during training. Additionally, these testing latencies were also different from those of a control group that only received a shock unrelated to context. Moreover, nuclear NF-kappa B DNA-binding activity was augmented in the aversive and the appetitive tasks when compared with control and naïve animals. NF-kappa B inhibition by Sulfasalazine injected either in the Hippocampus, Amygdala or Nucleus accumbens immediately after training was able to impair retention in both training versions. Our results suggest that NF-kappa B is a critical molecular step, in different brain areas on memory consolidation. This was the case for both the IA task and also the modified version of the same task where the footshock was omitted during training. This work aims to further investigate how appetitive and aversive memories are consolidated. PMID:28439227

  1. mTORC2 controls actin polymerization required for consolidation of long-term memory

    Science.gov (United States)

    Huang, Wei; Zhu, Ping Jun; Zhang, Shixing; Zhou, Hongyi; Stoica, Loredana; Galiano, Mauricio; Krnjević, Krešimir; Roman, Gregg; Costa-Mattioli, Mauro

    2013-01-01

    A major goal of biomedical research has been the identification of molecular mechanisms that can enhance memory. Here we report a novel signaling pathway that regulates the conversion from short- to long-term memory. The mTOR complex 2 (mTORC2), which contains the key regulatory protein Rictor (Rapamycin-Insensitive Companion of mTOR), was discovered only recently, and little is known about its physiological role. We show that conditional deletion of rictor in the postnatal murine forebrain greatly reduces mTORC2 activity and selectively impairs both long-term memory (LTM) and the late (but not the early) phase of hippocampal long-term potentiation (LTP). Actin polymerization is reduced in the hippocampus of mTORC2-deficient mice and its restoration rescues both L-LTP and LTM. More importantly, a compound that selectively promotes mTORC2 activity converts early-LTP into late-LTP and enhances LTM. These findings indicate that mTORC2 could be a novel therapeutic target for the treatment of cognitive dysfunction. PMID:23455608

  2. mTORC2 controls actin polymerization required for consolidation of long-term memory.

    Science.gov (United States)

    Huang, Wei; Zhu, Ping Jun; Zhang, Shixing; Zhou, Hongyi; Stoica, Loredana; Galiano, Mauricio; Krnjević, Krešimir; Roman, Gregg; Costa-Mattioli, Mauro

    2013-04-01

    A major goal of biomedical research is the identification of molecular and cellular mechanisms that underlie memory storage. Here we report a previously unknown signaling pathway that is necessary for the conversion from short- to long-term memory. The mammalian target of rapamycin (mTOR) complex 2 (mTORC2), which contains the regulatory protein Rictor (rapamycin-insensitive companion of mTOR), was discovered only recently and little is known about its function. We found that conditional deletion of Rictor in the postnatal murine forebrain greatly reduced mTORC2 activity and selectively impaired both long-term memory (LTM) and the late phase of hippocampal long-term potentiation (L-LTP). We also found a comparable impairment of LTM in dTORC2-deficient flies, highlighting the evolutionary conservation of this pathway. Actin polymerization was reduced in the hippocampus of mTORC2-deficient mice and its restoration rescued both L-LTP and LTM. Moreover, a compound that promoted mTORC2 activity converted early LTP into late LTP and enhanced LTM. Thus, mTORC2 could be a therapeutic target for the treatment of cognitive dysfunction.

  3. Time-dependent effects of cardiovascular exercise on memory

    DEFF Research Database (Denmark)

    Roig, Marc; Thomas, Richard; Mang, Cameron S

    2016-01-01

    We present new evidence supporting the hypothesis that the effects of cardiovascular exercise on memory can be regulated in a time-dependent manner. When the exercise stimulus is temporally coupled with specific phases of the memory formation process, a single bout of cardiovascular exercise may ...

  4. Environmental Enrichment Modifies the PKA-Dependence of Hippocampal LTP and Improves Hippocampus-Dependent Memory

    OpenAIRE

    Duffy, Steven N.; Craddock, Kenneth J.; Abel, Ted; Nguyen, Peter V.

    2001-01-01

    cAMP-dependent protein kinase (PKA) is critical for the expression of some forms of long-term potentiation (LTP) in area CA1 of the mouse hippocampus and for hippocampus-dependent memory. Exposure to spatially enriched environments can modify LTP and improve behavioral memory in rodents, but the molecular bases for the enhanced memory performance seen in enriched animals are undefined. We tested the hypothesis that exposure to a spatially enriched environment may alter the PKA dependence of h...

  5. Phosphodiesterase 11A (PDE11A), Enriched in Ventral Hippocampus Neurons, is Required for Consolidation of Social but not Nonsocial Memories in Mice.

    Science.gov (United States)

    Hegde, Shweta; Capell, Will R; Ibrahim, Baher A; Klett, Jennifer; Patel, Neema S; Sougiannis, Alexander T; Kelly, Michy P

    2016-11-01

    The capacity to form long-lasting social memories is critical to our health and survival. cAMP signaling in the ventral hippocampal formation (VHIPP) appears to be required for social memory formation, but the phosphodiesterase (PDE) involved remains unknown. Previously, we showed that PDE11A, which degrades cAMP and cGMP, is preferentially expressed in CA1 and subiculum of the VHIPP. Here, we determine whether PDE11A is expressed in neurons where it could directly influence synaptic plasticity and whether expression is required for the consolidation and/or retrieval of social memories. In CA1, and possibly CA2, PDE11A4 is expressed throughout neuronal cell bodies, dendrites (stratum radiatum), and axons (fimbria), but not astrocytes. Unlike PDE2A, PDE9A, or PDE10A, PDE11A4 expression begins very low at postnatal day 7 (P7) and dramatically increases until P28, at which time it stabilizes to young adult levels. This expression pattern is consistent with the fact that PDE11A is required for social long-term memory (LTM) formation during adolescence and adulthood. Male and female PDE11 knockout (KO) mice show normal short-term memory (STM) for social odor recognition (SOR) and social transmission of food preference (STFP), but no LTM 24 h post training. Importantly, PDE11A KO mice show normal LTM for nonsocial odor recognition. Deletion of PDE11A may impair memory consolidation by impairing requisite protein translation in the VHIPP. Relative to WT littermates, PDE11A KO mice show reduced expression of RSK2 and lowered phosphorylation of S6 (pS6-235/236). Together, these data suggest PDE11A is selectively required for the proper consolidation of recognition and associative social memories.

  6. Alcohol and Memory: Storage and State Dependency

    Science.gov (United States)

    Parker, Elizabeth S.; And Others

    1976-01-01

    Effects of acute alcohol intoxication on the storage phase of memory were evaluated with two tasks that minimized response retrieval: unpaced paired-associate learning with highly available responses and forced-choice picture recognition. It was concluded that storage processes are sensitive to disruption by alcohol. (CHK)

  7. Role of 5-HT5A receptors in the consolidation of memory.

    Science.gov (United States)

    Gonzalez, Roberto; Chávez-Pascacio, Karla; Meneses, Alfredo

    2013-09-01

    5-HT5 receptor occurs in brain areas implicated in learning and memory. Hence, the effects (0.01-3.0 mg/kg) of SB-6995516 (a 5-HT5A receptor antagonist) in the associative learning task of autoshaping were studied. The results showed that post-training injection of SB-699551 decreased conditioned responses (CR) during short-term (STM; 1.5h; at 0.1mg/kg) and long-term memory (LTM; 24 h; at 3.0 mg/kg) relative to the vehicle animals. Moreover, considering that there are no selective 5-HT5A receptor agonists, next, diverse doses of the serotonin precursor l-tryptophan were studied during STM and LTM, showing that l-tryptophan (5-100mg/kg) facilitated performance, particularly at 50mg/kg. In interactions experiments, l-tryptophan (50 mg/kg) attenuated the impairment effect induced by SB-699551 (either 0.3 or 3.0 mg/kg). All together this evidence suggests that the blockade of 5-HT5A receptor appear to be able to impair STM and LTM (24 h), while its stimulation might facilitate it. Of course further investigation is necessary, meanly with selective 5-HT5A compounds are necessary.

  8. MEMORY MODULATION

    Science.gov (United States)

    Roozendaal, Benno; McGaugh, James L.

    2011-01-01

    Our memories are not all created equally strong: Some experiences are well remembered while others are remembered poorly, if at all. Research on memory modulation investigates the neurobiological processes and systems that contribute to such differences in the strength of our memories. Extensive evidence from both animal and human research indicates that emotionally significant experiences activate hormonal and brain systems that regulate the consolidation of newly acquired memories. These effects are integrated through noradrenergic activation of the basolateral amygdala which regulates memory consolidation via interactions with many other brain regions involved in consolidating memories of recent experiences. Modulatory systems not only influence neurobiological processes underlying the consolidation of new information, but also affect other mnemonic processes, including memory extinction, memory recall and working memory. In contrast to their enhancing effects on consolidation, adrenal stress hormones impair memory retrieval and working memory. Such effects, as with memory consolidation, require noradrenergic activation of the basolateral amygdala and interactions with other brain regions. PMID:22122145

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

    Science.gov (United States)

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

    2013-03-20

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

  10. Influence of three-day morphine-treatment upon impairment of memory consolidation induced by cannabinoid infused into the dorsal hippocampus in rats.

    Science.gov (United States)

    Zarrindast, Mohammad Reza; Navaeian, Majid; Nasehi, Mohammad

    2011-01-01

    In the present study, the effects of morphine treatment upon reduction of memory consolidation by post-training administration of the non-selective cannabinoid CB(1)/CB(2) receptor agonist, WIN55,212-2, into the dorsal hippocampus (intra-CA1) have been investigated in rats. Step-through inhibitory avoidance apparatus was used to test memory retrieval, which was made of two white and dark compartments. In training day, electric shocks were delivered to the grid floor of the dark compartment. On the test day, the animal was placed in the white compartment and allowed to enter the dark compartment. The latency with which the animal crossed into the dark compartment was recorded as memory retrieval. Morphine was injected subcutaneously (S.C.), once daily for three days, followed by a five day morphine-free period before training. Bilateral post-training intra-CA1 infusions of WIN55,212-2 (0.25 and 0.5 μg/rat) shortened the step-through latency, which suggested impaired memory consolidation. The deleterious effect of WIN55,212-2 (0.5 μg/rat) was prevented in rats previously injected with morphine (10 mg/kg/day × 3 days, S.C.). Prevention of the WIN55,212-2-induced amnesic-like effect was counteracted by the mu-receptor antagonist, naloxone, and the dopamine D(2) receptor antagonist, sulpiride, but not by the D(1) receptor antagonist, SCH 23390, when administered prior to each morphine injection. The results have suggested that subchronic morphine treatment may cause mu-opioid and D(2) receptor sensitization, which in turn prevents impairment of memory consolidation induced by WIN55,212-2.

  11. Time for considering constraints on procedural memory consolidation processes: Comment on Pan and Rickard (2015) with specific reference to developmental changes.

    Science.gov (United States)

    Adi-Japha, Esther; Karni, Avi

    2016-05-01

    In the acquisition of some motor skills, sleep may be necessary for the completion of procedural memory consolidation processes, as expressed in delayed "offline" performance gains. Pan and Rickard (2015) conducted an original meta-analysis of the literature on performing an explicitly instructed finger movement sequence and tested the role of sleep versus wake in the enhancement of performance over posttraining delay periods. In this comment we propose that a more-biological, process-oriented framework is needed, allowing for more than a yes-no answer to the question addressed, and suggest methodological issues that may affect the target meta-analysis. We argue that different task demands, task conditions, and developmental differences should be considered a priori rather than expected to emerge from pooled data. For example, several recent studies have indicated that there is a qualitative change in the time course of procedural memory consolidation processes at puberty, between the ages of 12 and 17. Before puberty, consolidation processes are reflected in enhancement of task performance over sleep and wake periods alike. In their extensive set of relevant empirical data the authors included a number of developmental studies comparing children with adults (expecting "child status" effects) but did not fully consider developmental changes. We show that the inclusion of the 6 studies of childhood, comprising 13 groups, biases the meta-analysis toward the conclusion that skill enhancement is similar across wake and sleep periods. (PsycINFO Database Record

  12. Memory Insensitive Simplification for View-Dependent Refinement

    Energy Technology Data Exchange (ETDEWEB)

    Lindstrom, P

    2002-04-03

    We present an algorithm for end-to-end out-of-core simplification and view-dependent visualization of large surfaces. The method consists of three phases: (1) memory insensitive simplification; (2) memory insensitive construction of a level-of-detail hierarchy; and (3) run-time, output sensitive, view-dependent rendering and navigation of the mesh. The first two off-line phases are performed entirely on disk, and use only a small, constant amount of memory, whereas the run-time component relies on memory mapping to page in only the rendered parts of the mesh in a cache coherent manner. As a result, we are able to process and visualize arbitrarily large meshes given a sufficient amount of disk space--a constant multiple of the size of the input mesh. Similar to recent work on out-of-core simplification, our memory insensitive method uses vertex clustering on a uniform octree grid to coarsen a mesh and create a hierarchy, and a quadric error mettic to choose vertex positions at all levels of resolution. We show how the quadric information can be used to concisely represent vertex position, surface normal, error, and curvature information for anisotropic view-dependent coarsening and silhouette preservation. The focus of this paper is on the out-of-core construction of a level-of-detail hierarchy---our framework is general enough to incorporate many different aspects of view-dependent rendering. We therefore emphasize the off-line phases of our method, and report on their theoretical and experimental memory and disk usage and execution time. Our results indicate on average one to two orders of magnitude improvement in processing speed over previous out-of-core methods. Meanwhile, all phases of the method are both disk and memory efficient, and are fairly straightforward to implement.

  13. Immediate recall influences the effects of pre-encoding stress on emotional episodic long-term memory consolidation in healthy young men.

    Science.gov (United States)

    Wolf, Oliver T

    2012-05-01

    The stress-associated activation of the hypothalamus-pituitary-adrenal axis influences memory. Several studies have supported the notion that post-learning stress enhances memory consolidation, while pre-retrieval stress impairs retrieval. Findings regarding the effects of pre-encoding stress, in contrast, have been rather inconsistent. In the current two studies, the impact of an immediate retrieval task on these effects was explored. In the first study, 24 healthy young male participants were exposed to a psychosocial laboratory stressor (Trier Social Stress Test) or a control condition before viewing positive, negative, and neutral photographs, which were accompanied by a brief narrative. Immediate as well as delayed (24 h later) free recall was assessed. Stress was expected to enhance emotional long-term memory without affecting immediate recall performance. Stress caused a significant increase in salivary cortisol concentrations but had no significant effects on immediate or delayed retrieval performance, even though a trend toward poorer memory of the stress group was apparent. Based on these findings, the second experiment tested the hypothesis that the beneficial effects of stress on emotional long-term memory performance might be abolished by an immediate recall test. In the second study (n = 32), the same design was used, except for the omission of the immediate retrieval test. This time stressed participants recalled significantly more negative photographs compared to the control group. The present study indicates that an immediate retrieval attempt of material studied after stress exposure can prevent or even reverse the beneficial effects of pre-encoding stress on emotional long-term memory consolidation.

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

    Directory of Open Access Journals (Sweden)

    Vafaei A.L.

    2008-03-01

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

  15. Dose-Dependent Effect of Curcumin on Learning and Memory Deficit in Kainate-Epileptic Rats

    Directory of Open Access Journals (Sweden)

    Zahra Kiasalari

    2014-09-01

    Full Text Available Background & objectives : Epileptic seizures accompany disturbances in learning, memory, and cognitive skills. With regard to antiepileptic potential of curcumin and its beneficial effect on memory, the effect of its administration on learning and memory in kainate-epileptic rats was investigated.   Methods: Forty male rats were divided into sham, positive control ( valproate-treated epileptic, epileptic, and two curcumin-treated epileptic groups. Rat model of epilepsy was induced by unilateral intrahippocampal administration of 4 μg of kainate per rat. Rats received intraperitoneal injection of curcumin (50 and 100 mg/kg daily for 1 week before surgery. For evaluation of learning and memory, initial (IL and step-through latencies (STL were determined using passive avoidance test and alternation behavior percentage was obtained according to Y maze test.   Results: Regarding IL, there was no significant difference between the groups. In contrast, STL significantly decreased in curcumin-50-treated epileptic group (p<0.05 (a change from 263.1 to 184.5 s. However, this parameter significantly increased in curcumin-100-treated epileptic group as compared to epileptic group (p<0.01 (a change from 263.1 to 220.3 s. In addition, STL was also significantly higher in valproic acid-treated epileptic group versus epileptic group (p<0.05 (a change from 145.7 to 210.3 s. Alternation percentage was also significantly higher in curcumin-50- and curcumin-100-treated epileptic groups relative to epileptic group (p<0.05 (a change from 60.5 to 77.6 and 80.3%.   Conclusion: Curcumin could dose-dependently enhance the consolidation and recall in epileptic animals and could improve spatial memory in such animals.

  16. Working memory differences in long-distance dependency resolution

    Science.gov (United States)

    Nicenboim, Bruno; Vasishth, Shravan; Gattei, Carolina; Sigman, Mariano; Kliegl, Reinhold

    2015-01-01

    There is a wealth of evidence showing that increasing the distance between an argument and its head leads to more processing effort, namely, locality effects; these are usually associated with constraints in working memory (DLT: Gibson, 2000; activation-based model: Lewis and Vasishth, 2005). In SOV languages, however, the opposite effect has been found: antilocality (see discussion in Levy et al., 2013). Antilocality effects can be explained by the expectation-based approach as proposed by Levy (2008) or by the activation-based model of sentence processing as proposed by Lewis and Vasishth (2005). We report an eye-tracking and a self-paced reading study with sentences in Spanish together with measures of individual differences to examine the distinction between expectation- and memory-based accounts, and within memory-based accounts the further distinction between DLT and the activation-based model. The experiments show that (i) antilocality effects as predicted by the expectation account appear only for high-capacity readers; (ii) increasing dependency length by interposing material that modifies the head of the dependency (the verb) produces stronger facilitation than increasing dependency length with material that does not modify the head; this is in agreement with the activation-based model but not with the expectation account; and (iii) a possible outcome of memory load on low-capacity readers is the increase in regressive saccades (locality effects as predicted by memory-based accounts) or, surprisingly, a speedup in the self-paced reading task; the latter consistent with good-enough parsing (Ferreira et al., 2002). In sum, the study suggests that individual differences in working memory capacity play a role in dependency resolution, and that some of the aspects of dependency resolution can be best explained with the activation-based model together with a prediction component. PMID:25852623

  17. Working memory differences in long-distance dependency resolution

    Directory of Open Access Journals (Sweden)

    Bruno eNicenboim

    2015-03-01

    Full Text Available There is a wealth of evidence showing that increasing the distance between an argument and its head leads to more processing effort, namely, locality effects; these are usually associated with constraints in working memory (DLT: Gibson, 2000; activation-based model: Lewis and Vasishth, 2005. In SOV languages, however, the opposite effect has been found: antilocality (see discussion in Levy et al., 2013. Antilocality effects can be explained by the expectation-based approach as proposed by Levy (2008 or by the activation-based model of sentence processing as proposed by Lewis and Vasishth (2005.We report an eye-tracking and a self-paced reading study with sentences in Spanish together with measures of individual differences to examine the distinction between expectation- and memory-based accounts, and within memory-based accounts the further distinction between DLT and the activation-based model. The experiments show that (i antilocality effects as predicted by the expectation account appear only for high-capacity readers; (ii increasing dependency length by interposing material that modifies the head of the dependency (the verb produces stronger facilitation than increasing dependency length with material that does not modify the head; this is in agreement with the activation-based model but not with the expectation account; and (iii a possible outcome of memory load on low-capacity readers is the increase in regressive saccades (locality effects as predicted by memory-based accounts or, surprisingly, a speedup in the self-paced reading task; the latter consistent with good-enough parsing (Ferreira et al., 2002. In sum, the study suggests that individual differences in working memory capacity play a role in dependency resolution, and that some of the aspects of dependency resolution can be best explained with the activation-based model together with a prediction component.

  18. Common chromosomal fragile sites (CFS) may be involved in normal and traumatic cognitive stress memory consolidation and altered nervous system immunity.

    Science.gov (United States)

    Gericke, G S

    2010-05-01

    Previous reports of specific patterns of increased fragility at common chromosomal fragile sites (CFS) found in association with certain neurobehavioural disorders did not attract attention at the time due to a shift towards molecular approaches to delineate neuropsychiatric disorder candidate genes. Links with miRNA, altered methylation and the origin of copy number variation indicate that CFS region characteristics may be part of chromatinomic mechanisms that are increasingly linked with neuroplasticity and memory. Current reports of large-scale double-stranded DNA breaks in differentiating neurons and evidence of ongoing DNA demethylation of specific gene promoters in adult hippocampus may shed new light on the dynamic epigenetic changes that are increasingly appreciated as contributing to long-term memory consolidation. The expression of immune recombination activating genes in key stress-induced memory regions suggests the adoption by the brain of this ancient pattern recognition and memory system to establish a structural basis for long-term memory through controlled chromosomal breakage at highly specific genomic regions. It is furthermore considered that these mechanisms for management of epigenetic information related to stress memory could be linked, in some instances, with the transfer of the somatically acquired information to the germline. Here, rearranged sequences can be subjected to further selection and possible eventual retrotranscription to become part of the more stable coding machinery if proven to be crucial for survival and reproduction. While linkage of cognitive memory with stress and fear circuitry and memory establishment through structural DNA modification is proposed as a normal process, inappropriate activation of immune-like genomic rearrangement processes through traumatic stress memory may have the potential to lead to undesirable activation of neuro-inflammatory processes. These theories could have a significant impact on the

  19. Long memory and tail dependence in trading volume and volatility

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    2013-01-01

    We investigate the relationship between volatility, measured by realized volatility, and trading volume for 25 NYSE stocks. We show that volume and volatility are long memory but not fractionally cointegrated in most cases. We also find right tail dependence in the volatility and volume innovations...

  20. Long memory and tail dependence in trading volume and volatility

    DEFF Research Database (Denmark)

    Rossi, Eduardo; Santucci de Magistris, Paolo

    2013-01-01

    We investigate the relationship between volatility, measured by realized volatility, and trading volume for 25 NYSE stocks. We show that volume and volatility are long memory but not fractionally cointegrated in most cases. We also find right tail dependence in the volatility and volume innovations...

  1. Consolidation of remote fear memories involves Corticotropin-Releasing Hormone (CRH) receptor type 1-mediated enhancement of AMPA receptor GluR1 signaling in the dentate gyrus.

    Science.gov (United States)

    Thoeringer, Christoph K; Henes, Kathrin; Eder, Matthias; Dahlhoff, Maik; Wurst, Wolfgang; Holsboer, Florian; Deussing, Jan M; Moosmang, Sven; Wotjak, Carsten T

    2012-02-01

    Persistent dreadful memories and hyperarousal constitute prominent psychopathological features of posttraumatic stress disorder (PTSD). Here, we used a contextual fear conditioning paradigm to demonstrate that conditional genetic deletion of corticotropin-releasing hormone (CRH) receptor 1 within the limbic forebrain in mice significantly reduced remote, but not recent, associative and non-associative fear memories. Per os treatment with the selective CRHR1 antagonist DMP696 (3 mg/kg) attenuated consolidation of remote fear memories, without affecting their expression and retention. This could be achieved, if DMP696 was administered for 1 week starting as late as 24 h after foot shock. Furthermore, by combining electrophysiological recordings and western blot analyses, we demonstrate a delayed-onset and long-lasting increase in AMPA receptor (AMPAR) GluR1-mediated signaling in the dentate gyrus (DG) of the dorsal hippocampus 1 month after foot shock. These changes were absent from CRHR1-deficient mice and after DMP696 treatment. Inactivation of hippocampal GluR1-containing AMPARs by antisense oligonucleotides or philantotoxin 433 confirmed the behavioral relevance of AMPA-type glutamatergic neurotransmission in maintaining the high levels of remote fear in shocked mice with intact CRHR1 signaling. We conclude that limbic CRHR1 receptors enhance the consolidation of remote fear memories in the first week after foot shock by increasing the expression of Ca(2+)-permeable GluR1-containing AMPARs in the DG. These findings suggest both receptors as rational targets for the prevention and therapy, respectively, of psychopathology associated with exaggerated fear memories, such as PTSD.

  2. The critical role of sleep spindles in hippocampal-dependent memory: a pharmacology study.

    Science.gov (United States)

    Mednick, Sara C; McDevitt, Elizabeth A; Walsh, James K; Wamsley, Erin; Paulus, Martin; Kanady, Jennifer C; Drummond, Sean P A

    2013-03-06

    An important function of sleep is the consolidation of memories, and features of sleep, such as rapid eye movement (REM) or sleep spindles, have been shown to correlate with improvements in discrete memory domains. Because of the methodological difficulties in modulating sleep, however, a causal link between specific sleep features and human memory consolidation is lacking. Here, we experimentally manipulated specific sleep features during a daytime nap via direct pharmacological intervention. Using zolpidem (Ambien), a short-acting GABAA agonist hypnotic, we show increased sleep spindle density and decreased REM sleep compared with placebo and sodium oxybate (Xyrem). Naps with increased spindles produced significantly better verbal memory and significantly worse perceptual learning but did not affect motor learning. The experimental spindles were similar to control spindles in amplitude and frequency, suggesting that the experimental intervention enhanced normal sleep processes. Furthermore, using statistical methods, we demonstrate for the first time a critical role of spindles in human hippocampal memory performance. The gains in memory consolidation exceed sleep-alone or control conditions and demonstrate the potential for targeted, exceptional memory enhancement in healthy adults with pharmacologically modified sleep.

  3. Applied pressure-dependent anisotropic grain connectivity in shock consolidated MgB{sub 2} samples

    Energy Technology Data Exchange (ETDEWEB)

    Ohashi, Wataru [Graduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan); Takenaka, Kenta [Graduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan); Kondo, Tadashi [Graduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan); Tamaki, Hideyuki [Graduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan); Matsuzawa, Hidenori [Graduate School of Engineering, University of Yamanashi, Takeda 4-3-11, Kofu 400-8511 (Japan)]. E-mail: matuzawa@mx3.nns.ne.jp; Kai, Shoichiro [Advanced Materials and Process Development Group, Explosive Division, Asahi Kasei Chemicals Corporation, Oita 870-0392 (Japan); Kakimoto, Etsuji [Advanced Materials and Process Development Group, Explosive Division, Asahi Kasei Chemicals Corporation, Oita 870-0392 (Japan); Takano, Yoshihiko [National Institute for Materials Science, Tsukuba 305-0047 (Japan); Minehara, Eisuke [FEL Laboratory, Tokai Site, Japan Atomic Energy Research Institute, Shirakata-shirane 2-4, Tokai, Ibaraki 319-1195 (Japan)

    2006-09-15

    Three different cylindrical MgB{sub 2} bulk samples were prepared by the underwater shock consolidation method in which shock waves of several GPa, generated by detonation of explosives, were applied to a metallic cylinder containing commercially available MgB{sub 2} powders with no additives. Resistivity anisotropy of the samples increased with shock pressure. The highest- and medium-pressure applied samples had finite resistivities in the radial direction for the whole temperature range down to 12 K, whereas their axial and azimuthal resistivities dropped to zero at 32-35 K. By contrast, the lowest-pressure applied sample was approximately isotropic with a normal-state resistivity of {approx}40 {mu}{omega} cm, an onset temperature of {approx}38.5 K, and a transition width of {approx}4.5 K. These extremely anisotropic properties would have resulted from the distortion of grain boundaries and grain cores, caused by the shock pressures and their repeated bouncing.

  4. Consolidation of Associative and Item Memory Is Related to Post-Encoding Functional Connectivity between the Ventral Tegmental Area and Different Medial Temporal Lobe Subregions during an Unrelated Task.

    Science.gov (United States)

    Tompary, Alexa; Duncan, Katherine; Davachi, Lila

    2015-05-13

    It is well established that the hippocampus and perirhinal cortex (PrC) encode associative and item representations, respectively. However, less is known about how item and associative memories are consolidated. We used high-resolution fMRI in humans to measure how functional connectivity between these distinct medial temporal lobe regions with the ventral tegmental area (VTA) after a paired associate encoding task is related to both immediate and 24 h item and associative memory performance. We found that the strength of post-encoding functional connectivity between the VTA and CA1 selectively correlated with long-term associative memory, despite subjects actively engaging in an unrelated task during this period. Conversely, VTA-PrC functional connectivity during the same period correlated with long-term item memory. Critically, connectivity between VTA and these MTL regions were only related to memory tested at a 24 h delay, implicating midbrain connectivity in the consolidation of distinct forms of memory.

  5. Social networks: Evolving graphs with memory dependent edges

    Science.gov (United States)

    Grindrod, Peter; Parsons, Mark

    2011-10-01

    The plethora of digital communication technologies, and their mass take up, has resulted in a wealth of interest in social network data collection and analysis in recent years. Within many such networks the interactions are transient: thus those networks evolve over time. In this paper we introduce a class of models for such networks using evolving graphs with memory dependent edges, which may appear and disappear according to their recent history. We consider time discrete and time continuous variants of the model. We consider the long term asymptotic behaviour as a function of parameters controlling the memory dependence. In particular we show that such networks may continue evolving forever, or else may quench and become static (containing immortal and/or extinct edges). This depends on the existence or otherwise of certain infinite products and series involving age dependent model parameters. We show how to differentiate between the alternatives based on a finite set of observations. To test these ideas we show how model parameters may be calibrated based on limited samples of time dependent data, and we apply these concepts to three real networks: summary data on mobile phone use from a developing region; online social-business network data from China; and disaggregated mobile phone communications data from a reality mining experiment in the US. In each case we show that there is evidence for memory dependent dynamics, such as that embodied within the class of models proposed here.

  6. Environmental enrichment modifies the PKA-dependence of hippocampal LTP and improves hippocampus-dependent memory.

    Science.gov (United States)

    Duffy, S N; Craddock, K J; Abel, T; Nguyen, P V

    2001-01-01

    cAMP-dependent protein kinase (PKA) is critical for the expression of some forms of long-term potentiation (LTP) in area CA1 of the mouse hippocampus and for hippocampus-dependent memory. Exposure to spatially enriched environments can modify LTP and improve behavioral memory in rodents, but the molecular bases for the enhanced memory performance seen in enriched animals are undefined. We tested the hypothesis that exposure to a spatially enriched environment may alter the PKA dependence of hippocampal LTP. Hippocampal slices from enriched mice showed enhanced LTP following a single burst of 100-Hz stimulation in the Schaffer collateral pathway of area CA1. In slices from nonenriched mice, this single-burst form of LTP was less robust and was unaffected by Rp-cAMPS, an inhibitor of PKA. In contrast, the enhanced LTP in enriched mice was attenuated by Rp-cAMPS. Enriched slices expressed greater forskolin-induced, cAMP-dependent synaptic facilitation than did slices from nonenriched mice. Enriched mice showed improved memory for contextual fear conditioning, whereas memory for cued fear conditioning was unaffected following enrichment. Our data indicate that exposure of mice to spatial enrichment alters the PKA dependence of LTP and enhances one type of hippocampus-dependent memory. Environmental enrichment can transform the pharmacological profile of hippocampal LTP, possibly by altering the threshold for activity-dependent recruitment of the cAMP-PKA signaling pathway following electrical and chemical stimulation. We suggest that experience-dependent plasticity of the PKA dependence of hippocampal LTP may be important for regulating the efficacy of hippocampus-based memory.

  7. Possible interaction of hippocampal nitric oxide and calcium/calmodulin-dependent protein kinase II on reversal of spatial memory impairment induced by morphine.

    Science.gov (United States)

    Farahmandfar, Maryam; Kadivar, Mehdi; Naghdi, Nasser

    2015-03-15

    The opioid system plays an important role in learning and memory by modulation of different molecules in the brain. The aim of the present study was to investigate the role of hippocampal nitric oxide and calcium/calmodulin-dependent protein kinase II (CaMKII) on the morphine-induced modulation of spatial memory consolidation in male rats. Spatial memory was assessed in Morris water maze task by a single training session of eight trials followed by a probe trial and visible test 24h later. Our data indicated that post-training administration of L-arginine, a nitric oxide precursor (6 and 9 µg/rat, intra-CA1) significantly decreased amnesia induced by morphine (10 mg/kg) in spatial memory consolidation. A reversal effect of L-arginine on morphine-induced amnesia prevented by KN-93 (N-[2-(N-(4-chlorocinnamyl)-N-methylaminomethyl) phenyl]-N-[2-hydroxyethyl] methoxybenzenesulfnamide), CaMKII inhibitor, (10 nmol/0.5 µl/site). In addition, post-training injection of L-NAME, (NG-nitro-L-arginine methyl ester), a nitric oxide synthase (NOS) inhibitor (10 and 15 µg/rat) or KN-93 (10 nmol/0.5 µl/site) with lower dose of morphine (2.5 mg/kg), which did not induce amnesia by itself, caused inhibition of memory consolidation. We also showed that co-administration of L-arginine (9 µg/rat) and morphine (10 mg/kg) significantly increased CaMKII activity in the rat hippocampus. On the other hand, administration of L-NAME (10 µg/rat) led to a decrease in the haippocampal activity of CaMKII in morphine-treated (2.5mg/kg) animals. These results indicate that acute single exposure to morphine can modulate consolidation of spatial memory, which may be mediated by a hippocampal nitrergic system and CaMKII activity.

  8. About sleep's role in memory.

    Science.gov (United States)

    Rasch, Björn; Born, Jan

    2013-04-01

    Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.

  9. VGF and Its C-Terminal Peptide TLQP-62 Regulate Memory Formation in Hippocampus via a BDNF-TrkB-Dependent Mechanism.

    Science.gov (United States)

    Lin, Wei-Jye; Jiang, Cheng; Sadahiro, Masato; Bozdagi, Ozlem; Vulchanova, Lucy; Alberini, Cristina M; Salton, Stephen R

    2015-07-15

    Regulated expression and secretion of BDNF, which activates TrkB receptor signaling, is known to play a critical role in cognition. Identification of additional modulators of cognitive behavior that regulate activity-dependent BDNF secretion and/or potentiate TrkB receptor signaling would therefore be of considerable interest. In this study, we show in the adult mouse hippocampus that expression of the granin family gene Vgf and secretion of its C-terminal VGF-derived peptide TLQP-62 are required for fear memory formation. We found that hippocampal VGF expression and TLQP-62 levels were transiently induced after fear memory training and that sequestering secreted TLQP-62 peptide in the hippocampus immediately after training impaired memory formation. Reduced VGF expression was found to impair learning-evoked Rac1 induction and phosphorylation of the synaptic plasticity markers cofilin and synapsin in the adult mouse hippocampus. Moreover, TLQP-62 induced acute, transient activation of the TrkB receptor and subsequent CREB phosphorylation in hippocampal slice preparations and its administration immediately after training enhanced long-term memory formation. A critical role of BDNF-TrkB signaling as a downstream effector in VGF/TLQP-62-mediated memory consolidation was further revealed by posttraining activation of BDNF-TrkB signaling, which rescued impaired fear memory resulting from hippocampal administration of anti-VGF antibodies or germline VGF ablation in mice. We propose that VGF is a critical component of a positive BDNF-TrkB regulatory loop and, upon its induced expression by memory training, the TLQP-62 peptide rapidly reinforces BDNF-TrkB signaling, regulating hippocampal memory consolidation. Identification of the cellular and molecular mechanisms that regulate long-term memory formation and storage may provide alternative treatment modalities for degenerative and neuropsychiatric memory disorders. The neurotrophin BDNF plays a prominent role in cognitive

  10. Simultaneous consolidation and creep

    DEFF Research Database (Denmark)

    Krogsbøll, Anette

    1997-01-01

    Materials that exhibit creep under constant effective stress typically also show rate dependent behavior. The creep deformations and the rate sensitive behavior is very important when engineering and geological problems with large time scales are considered. When stress induced compaction...... (consolidation) is retarded by slow drainage of excess pore pressure it is expected that consolidation and creep occur simultaneously. A constitutive model adressing the problems of rate sensitive behavior and simultaneous consolidation and creep is presented....

  11. Autobiographical Memory Deficits in Alcohol-Dependent Patients with Short- and Long-Term Abstinence.

    Science.gov (United States)

    Nandrino, Jean-Louis; El Haj, Mohamad; Torre, Julie; Naye, Delphine; Douchet, Helyette; Danel, Thierry; Cottençin, Oliver

    2016-04-01

    Autobiographical memory (AM) enables the storage and retrieval of life experiences that allow individuals to build their sense of identity. Several AM impairments have been described in patients with alcohol abuse disorders without assessing whether such deficits can be recovered. This cross-sectional study aimed to identify whether the semantic (SAM) and episodic (EAM) dimensions of AM are affected in individuals with alcohol dependence after short-term abstinence (STA) or long-term abstinence (LTA). A second aim of this study was to examine the factors that could disrupt the efficiency of semantic and episodic AM (the impact of depression severity, cognitive functions, recent or early traumatic events, and drinking history variables). After clinical and cognitive evaluations (alcohol consumption, depression, anxiety, IQ, memory performance), AM was assessed with the Autobiographical Memory Interview in patients with recent (between 4 and 6 weeks) and longer (at least 6 months) abstinence. Participants were asked to retrieve the number and nature of traumatic or painful life experiences in recent or early life periods (using the Childhood Traumatic Events Scale). The 2 abstinent groups had lower global EAM and SAM scores than the control group. These scores were comparable for both abstinent groups. For childhood events, no significant differences were observed in SAM for both groups compared with control participants. For early adulthood and recent events, both STA and LTA groups had lower scores on both SAM and EAM. Moreover, there was a negative correlation between the length of substance consumption and SAM scores. This study highlighted a specific AM disorder in both episodic and semantic dimensions. These deficits remained after 6 months of abstinence. This AM impairment may be explained by compromised encoding and consolidation of memories during bouts of drinking. Copyright © 2016 by the Research Society on Alcoholism.

  12. Experience-dependent eye movements reflect hippocampus-dependent (aware) memory

    Science.gov (United States)

    Smith, Christine N.; Squire, Larry R.

    2008-01-01

    We investigated the relationship between experience-dependent eye movements, hippocampus-dependent memory, and aware memory. We measured eye movements in young adults, older adults, and memory-impaired patients with damage to the medial temporal lobe as they viewed 120 novel scenes and 120 previously viewed scenes. Participants indicated if each scene was old or new and also gave a confidence rating for the memory judgment. Young adults and older adults explored old scenes less than they explored new scenes, but the patients did not. For the young and older adults, this effect was observed only when participants were aware of the scene’s familiar or novel status. In a second experiment, young adults viewed scenes that were either new, had been viewed previously, or had been viewed previously but had been changed (i.e., an object within the scene was either added or removed). The only instructions were to pay attention to the scenes and view each scene as it appeared, and there was no expectation that memory would be tested. Directly after the first altered scene was presented, participants were asked to classify the scene as new, old, or old but changed. Participants who were aware of the manipulation preferentially viewed the changed region, but participants who were unaware did not. These findings suggest that experience-dependent eye movements reflect hippocampus-dependent (and aware) memory, even when participants have no expectation that memory is being tested; and they are consistent with the view that awareness of what is learned is a fundamental characteristic of hippocampus-dependent memory. PMID:19036976

  13. Consistency of Flashbulb Memories of September 11 over Long Delays: Implications for Consolidation and Wrong Time Slice Hypotheses

    Science.gov (United States)

    Kvavilashvili, Lia; Mirani, Jennifer; Schlagman, Simone; Foley, Kerry; Kornbrot, Diana E.

    2009-01-01

    The consistency of flashbulb memories over long delays provides a test of theories of memory for highly emotional events. This study used September 11, 2001 as the target event, with test-retest delays of 2 and 3 years. The nature and consistency of flashbulb memories were examined as a function of delay between the target event and an initial…

  14. A Role of Protein Degradation in Memory Consolidation after Initial Learning and Extinction Learning in the Honeybee ("Apis mellifera")

    Science.gov (United States)

    Felsenberg, Johannes; Dombrowski, Vincent; Eisenhardt, Dorothea

    2012-01-01

    Protein degradation is known to affect memory formation after extinction learning. We demonstrate here that an inhibitor of protein degradation, MG132, interferes with memory formation after extinction learning in a classical appetitive conditioning paradigm. In addition, we find an enhancement of memory formation when the same inhibitor is…

  15. Encoding, Consolidation, and Retrieval of Contextual Memory: Differential Involvement of Dorsal CA3 and CA1 Hippocampal Subregions

    Science.gov (United States)

    Daumas, Stephanie; Halley, Helene; Frances, Bernard; Lassalle, Jean-Michel

    2005-01-01

    Studies on human and animals shed light on the unique hippocampus contributions to relational memory. However, the particular role of each hippocampal subregion in memory processing is still not clear. Hippocampal computational models and theories have emphasized a unique function in memory for each hippocampal subregion, with the CA3 area acting…

  16. A Role of Protein Degradation in Memory Consolidation after Initial Learning and Extinction Learning in the Honeybee ("Apis mellifera")

    Science.gov (United States)

    Felsenberg, Johannes; Dombrowski, Vincent; Eisenhardt, Dorothea

    2012-01-01

    Protein degradation is known to affect memory formation after extinction learning. We demonstrate here that an inhibitor of protein degradation, MG132, interferes with memory formation after extinction learning in a classical appetitive conditioning paradigm. In addition, we find an enhancement of memory formation when the same inhibitor is…

  17. Role of Proteasome-Dependent Protein Degradation in Long-Term Operant Memory in "Aplysia"

    Science.gov (United States)

    Lyons, Lisa C.; Gardner, Jacob S.; Gandour, Catherine E.; Krishnan, Harini C.

    2017-01-01

    We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in "Aplysia" using an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through…

  18. Role of Proteasome-Dependent Protein Degradation in Long-Term Operant Memory in "Aplysia"

    Science.gov (United States)

    Lyons, Lisa C.; Gardner, Jacob S.; Gandour, Catherine E.; Krishnan, Harini C.

    2017-01-01

    We investigated the in vivo role of protein degradation during intermediate (ITM) and long-term memory (LTM) in "Aplysia" using an operant learning paradigm. The proteasome inhibitor MG-132 inhibited the induction and molecular consolidation of LTM with no effect on ITM. Remarkably, maintenance of steady-state protein levels through…

  19. About Sleep's Role in Memory

    Science.gov (United States)

    2013-01-01

    Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of “sleep and memory” research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems. PMID:23589831

  20. Reversal of apomorphine locomotor sensitization by a single post-conditioning trial treatment with a low autoreceptor dose of apomorphine: a memory re-consolidation approach.

    Science.gov (United States)

    Carrera, Marinete Pinheiro; Carey, Robert J; Dias, Flávia Regina Cruz; de Matos, Liana Wermelinger

    2011-07-01

    Sensitization is a common feature of psychostimulants and sensitization effects are generally considered to be linked to the addictive properties of these drugs. We used a conventional paired/unpaired Pavlovian protocol to induce a context specific sensitization to the locomotor stimulant effect of a high dose of apomorphine (2.0mg/kg). Two days following a 5 session sensitization induction phase, a brief 5min non-drug test for conditioning was conducted. Only the paired groups exhibited locomotor stimulant conditioned response effects. Immediately following this brief test for conditioning, the paired and the unpaired groups received injections of 0.05mg/kg apomorphine, 2.0mg/kg apomorphine or vehicle designed to differentially impact memory re-consolidation of the conditioning. Two days later, all groups received a sensitization challenge test with 2.0mg/kg apomorphine. The 2.0mg/kg apomorphine post-trial treatment potentiated sensitization while the 0.05mg/kg eliminated sensitization. These effects were only observed in the paired groups. The activation of dopaminergic systems by the high dose of apomorphine strengthened the drug/environment association whereas the inhibition of dopamine activity by the low auto-receptor dose eliminated this association. The results point to the importance of conditioning to context specific sensitization and targeting memory re-consolidation of conditioning as a paradigm to modify sensitization.

  1. Memory function in opioid-dependent patients treated with methadone or buprenorphine along with benzodiazepine: longitudinal change in comparison to healthy individuals

    Directory of Open Access Journals (Sweden)

    Rapeli Pekka

    2009-04-01

    Full Text Available Abstract Background Opioid-substitution treatment (OST for opioid dependence (OD has proven effective in retaining patients in treatment and reducing illegal opiate abuse and crime. Consequently, the World Health Organization (WHO has listed the opioid agonists methadone and buprenorphine as essential drugs for OD that should be available worldwide. In many areas of the world, OD is often associated with concomitant benzodiazepine (BZD dependence and abuse, which complicates treatment. However, possible changes in the cognitive functioning of these patients are not well-known. The present study is the first to examine longitudinal stability of memory function in OST patients with BZD use, thus providing a new tool for health policy authorities in evaluating the usefulness of OST. Methods Within the first two months (T1 and between 6–9 months (T2 after OST admission, we followed the working memory, immediate verbal memory, and memory consolidation of 13 methadone- and 15 buprenorphine- or buprenorphine/naloxone-treated patients with BZD dependence or abuse disorder. The results were compared to those of fifteen normal comparison participants. All participants also completed a self-reported memory complaint questionnaire on both occasions. Results Both patient groups performed statistically significantly worse than normal comparison participants in working memory at time points T1 and T2. In immediate verbal memory, as measured by list learning at T1, patients scored lower than normal comparison participants. Both patient groups reported significantly more subjective memory problems than normal comparison participants. Patients with more memory complaints recalled fewer items at T2 from the verbal list they had learned at T1 than those patients with fewer memory complaints. The significance of the main analyses remained nearly the same when the statistical tests were performed without buprenorphine-only patients leaving 12 patients to

  2. Post-Acquisition Release of Glutamate and Norepinephrine in the Amygdala Is Involved in Taste-Aversion Memory Consolidation

    Science.gov (United States)

    Guzman-Ramos, Kioko; Osorio-Gomez, Daniel; Moreno-Castilla, Perla; Bermudez-Rattoni, Federico

    2012-01-01

    Amygdala activity mediates the acquisition and consolidation of emotional experiences; we have recently shown that post-acquisition reactivation of this structure is necessary for the long-term storage of conditioned taste aversion (CTA). However, the specific neurotransmitters involved in such reactivation are not known. The aim of the present…

  3. GluN1 and GluN2A NMDA Receptor Subunits Increase in the Hippocampus during Memory Consolidation in the Rat

    Science.gov (United States)

    Cercato, Magali C.; Vázquez, Cecilia A.; Kornisiuk, Edgar; Aguirre, Alejandra I.; Colettis, Natalia; Snitcofsky, Marina; Jerusalinsky, Diana A.; Baez, María V.

    2017-01-01

    It is widely accepted that NMDA receptors (NMDAR) are required for learning and memory formation, and for synaptic plasticity induction. We have previously shown that hippocampal GluN1 and GluN2A NMDAR subunits significantly increased following habituation of rats to an open field (OF), while GluN2B remained unchanged. Similar results were obtained after CA1-long-term potentiation (LTP) induction in rat hippocampal slices. Other studies have also shown NMDAR up regulation at earlier and later time points after LTP induction or learning acquisition. In this work, we have studied NMDAR subunits levels in the hippocampus and prefrontal cortex (PFC) after OF habituation and after object recognition (OR), to find out whether rising of NMDAR subunits is a general and structure-specific feature during memory formation. In 1, 2 and 3 month old rats there was an increase in hippocampal GluN1 and GluN2A, but not in GluN2B levels 70 min after OF habituation. This rise overlaps with early phase of memory consolidation, suggesting a putative relationship between them. The increases fell down to control levels 90 min after training. Similar results were obtained in the hippocampus of adult rats 70 min after OR training, without changes in PFC. Following OF test or OR discrimination phase, NMDAR subunits remained unchanged. Hence, rising of hippocampal GluN1 and GluN2A appears to be a general feature after novel “spatial/discrimination” memory acquisition. To start investigating the dynamics and possible mechanisms of these changes, we have studied hippocampal neuron cultures stimulated by KCl to induce plasticity. GluN1 and GluN2A increased both in dendrites and neuronal bodies, reaching a maximum 75 min later and returning to control levels at 90 min. Translation and/or transcription and mobilization differentially contribute to this rise in subunits in bodies and dendrites. Our results showed that the NMDAR subunits increase follows a similar time course both in vitro and

  4. Dissociable effects of acetylcholinesterase inhibitors and phosphodiesterase type 5 inhibitors on object recognition memory: acquisition versus consolidation

    NARCIS (Netherlands)

    Prickaerts, L.; Sik, A.; Staay, van der F.J.; Vente, de J.; Blokland, A.

    2005-01-01

    Rationale Phosphodiesterase enzyme type 5 (PDE5) inhibitors and acetylcholinesterase (AChE) inhibitors have cognition-enhancing properties. However, it is not known whether these drug classes affect the same memory processes. Objective We investigated the memory-enhancing effects of the PDE5 inhibit

  5. Involvement of dopamine D1/D5 and D2 receptors in context-dependent extinction learning and memory reinstatement

    Directory of Open Access Journals (Sweden)

    Marion Agnes Emma Andre

    2016-01-01

    Full Text Available Dopamine contributes to the regulation of higher order information processing and executive control. It is important for memory consolidation processes, and for the adaptation of learned responses based on experience. In line with this, under aversive learning conditions, application of dopamine receptor antagonists prior to extinction result in enhanced memory reinstatement. Here, we investigated the contribution of the dopaminergic system to extinction and memory reinstatement (renewal of an appetitive spatial learning task in rodents. Rats were trained for 3 days in a T-maze (context ‘A’ to associate a goal arm with a food reward, despite low reward probability (acquisition phase. On day 4, extinction learning (unrewarded occurred, that was reinforced by a context change (‘B’. On day 5, re-exposure to the (unrewarded ‘A’-context took place (renewal of context ‘A’, followed by extinction of context ‘A’. In control animals, significant extinction occurred on day 4, that was followed by an initial memory reinstatement (renewal on day 5, that was, in turn, succeeded by extinction of renewal. Intracerebral treatment with a D1/D5-receptor antagonist prior to the extinction trials, elicited a potent enhancement of extinction in context ‘B’. By contrast, a D1/D5-agonist impaired renewal in context ’A’. Extinction in the ‘A’ context on day 5 was unaffected by the D1/D5-ligands. Treatment with a D2-receptor antagonist prior to extinction had no overall effect on extinction in context ‘B or renewal in context ‘A’, although extinction of the renewal effect was impaired on day 5, compared to controls.Taken together, these data suggest that dopamine acting on the D1/D5-receptor modulates both acquisition and consolidation of context-dependent extinction. By contrast, the D2-receptor may contribute to context-independent aspects of this kind of extinction learning.

  6. Involvement of Dopamine D1/D5 and D2 Receptors in Context-Dependent Extinction Learning and Memory Reinstatement

    Science.gov (United States)

    André, Marion Agnès Emma; Manahan-Vaughan, Denise

    2016-01-01

    Dopamine contributes to the regulation of higher order information processing and executive control. It is important for memory consolidation processes, and for the adaptation of learned responses based on experience. In line with this, under aversive learning conditions, application of dopamine receptor antagonists prior to extinction result in enhanced memory reinstatement. Here, we investigated the contribution of the dopaminergic system to extinction and memory reinstatement (renewal) of an appetitive spatial learning task in rodents. Rats were trained for 3 days in a T-maze (context “A”) to associate a goal arm with a food reward, despite low reward probability (acquisition phase). On day 4, extinction learning (unrewarded) occurred, that was reinforced by a context change (“B”). On day 5, re-exposure to the (unrewarded) “A” context took place (renewal of context “A”, followed by extinction of context “A”). In control animals, significant extinction occurred on day 4, that was followed by an initial memory reinstatement (renewal) on day 5, that was, in turn, succeeded by extinction of renewal. Intracerebral treatment with a D1/D5-receptor antagonist prior to the extinction trials, elicited a potent enhancement of extinction in context “B”. By contrast, a D1/D5-agonist impaired renewal in context “A”. Extinction in the “A” context on day 5 was unaffected by the D1/D5-ligands. Treatment with a D2-receptor antagonist prior to extinction had no overall effect on extinction in context “B” or renewal in context “A”, although extinction of the renewal effect was impaired on day 5, compared to controls. Taken together, these data suggest that dopamine acting on the D1/D5-receptor modulates both acquisition and consolidation of context-dependent extinction. By contrast, the D2-receptor may contribute to context-independent aspects of this kind of extinction learning. PMID:26834599

  7. Functional connectivity during light sleep is correlated with memory performance for face-location associations.

    NARCIS (Netherlands)

    Dongen, E.V. van; Takashima, A.; Barth, M.; Fernandez, G.S.E.

    2011-01-01

    The consolidation of declarative memories benefits from sleep. The neural mechanisms involved in sleep-dependent consolidation, however, are largely unknown. Here, we used a combination of functional magnetic resonance imaging, polysomnography and a face-location associative memory task to target ne

  8. Functional connectivity during light sleep is correlated with memory performance for face-location associations

    NARCIS (Netherlands)

    Dongen, E.V. van; Takashima, A.; Barth, M.; Fernandez, G.S.E.

    2011-01-01

    The consolidation of declarative memories benefits from sleep. The neural mechanisms involved in sleep-dependent consolidation, however, are largely unknown. Here, we used a combination of functional magnetic resonance imaging, polysomnography and a face–location associative memory task to target ne

  9. Strain-dependent differences in LTP and hippocampus-dependent memory in inbred mice.

    Science.gov (United States)

    Nguyen, P V; Abel, T; Kandel, E R; Bourtchouladze, R

    2000-01-01

    Many studies have used "reverse" genetics to produce "knock-out" and transgenic mice to explore the roles of various molecules in long-term potentiation (LTP) and spatial memory. The existence of a variety of inbred strains of mice provides an additional way of exploring the genetic bases of learning and memory. We examined behavioral memory and LTP expression in area CA1 of hippocampal slices prepared from four different inbred strains of mice: C57BL/6J, CBA/J, DBA/2J, and 129/SvEms-+(Ter?)/J. We found that LTP induced by four 100-Hz trains of stimulation was robust and long-lasting in C57BL/6J and DBA/2J mice but decayed in CBA/J and 129/SvEms-+(Ter?)/J mice. LTP induced by one 100-Hz train was significantly smaller after 1 hr in the 129/SvEms-+(Ter?)/J mice than in the other three strains. Theta-burst LTP was shorter lasting in CBA/J, DBA/2J, and 129/SvEms-+(Ter?)/J mice than in C57BL/6J mice. We also observed specific memory deficits, among particular mouse strains, in spatial and nonspatial tests of hippocampus-dependent memory. CBA/J mice showed defective learning in the Morris water maze, and both DBA/2J and CBA/J strains displayed deficient long-term memory in contextual and cued fear conditioning tests. Our findings provide strong support for a genetic basis for some forms of synaptic plasticity that are linked to behavioral long-term memory and suggest that genetic background can influence the electrophysiological and behavioral phenotypes observed in genetically modified mice generated for elucidating the molecular bases of learning, memory, and LTP.

  10. Consolidating the effects of waking and sleep on motor-sequence learning.

    Science.gov (United States)

    Brawn, Timothy P; Fenn, Kimberly M; Nusbaum, Howard C; Margoliash, Daniel

    2010-10-20

    Sleep is widely believed to play a critical role in memory consolidation. Sleep-dependent consolidation has been studied extensively in humans using an explicit motor-sequence learning paradigm. In this task, performance has been reported to remain stable across wakefulness and improve significantly after sleep, making motor-sequence learning the definitive example of sleep-dependent enhancement. Recent work, however, has shown that enhancement disappears when the task is modified to reduce task-related inhibition that develops over a training session, thus questioning whether sleep actively consolidates motor learning. Here we use the same motor-sequence task to demonstrate sleep-dependent consolidation for motor-sequence learning and explain the discrepancies in results across studies. We show that when training begins in the morning, motor-sequence performance deteriorates across wakefulness and recovers after sleep, whereas performance remains stable across both sleep and subsequent waking with evening training. This pattern of results challenges an influential model of memory consolidation defined by a time-dependent stabilization phase and a sleep-dependent enhancement phase. Moreover, the present results support a new account of the behavioral effects of waking and sleep on explicit motor-sequence learning that is consistent across a wide range of tasks. These observations indicate that current theories of memory consolidation that have been formulated to explain sleep-dependent performance enhancements are insufficient to explain the range of behavioral changes associated with sleep.

  11. Retrieval of Consolidated Spatial Memory in the Water Maze Is Correlated with Expression of pCREB and Egr1 in the Hippocampus of Aged Mice

    Directory of Open Access Journals (Sweden)

    GuoXia Zhou

    2013-02-01

    Full Text Available Objective: To study the relationship of the expression of phosphorylated cyclic AMP response element-binding protein (pCREB and early growth response protein 1 (Egr1 in the hippocampus of aged mice with retrieval of consolidated spatial memory in a water maze. Methods: Twenty-four aged mice were allocated into no training or probe test (naïve, no training but exposed to the same probe test (NTPRT, received training and probe test (PRT, and received training but no probe test (NPRT groups. Twelve mice were trained in a water maze over 14 days. After the final probe trial on day 15, all mice were anesthetized and the brains were removed. pCREB immunoreactivity (pCREB-ir and Egr1 immunoreactivity (Egr1-ir in the hippocampal CA1 and CA3 areas were examined. Results: pCREB-ir and Egr1-ir in the CA1 and CA3 areas of the NPRT and PRT groups were significantly higher than those of the naïve and NTPRT groups, and those in the PRT group were significantly higher than in the NPRT group. In all groups, pCREB-ir was significantly higher in the CA3 area compared to the CA1 area, while Egr1-ir was significantly higher in the CA1 area compared to the CA3 area. Conclusion: Retrieval, as well as formation, of consolidated spatial memory in the water maze is correlated with expression of pCREB and Egr1 in the hippocampus of aged mice.

  12. Role of Dopamine Receptors Subtypes, D1-Like and D2-Like, within the Nucleus Accumbens Subregions, Core and Shell, on Memory Consolidation in the One-Trial Inhibitory Avoidance Task

    Science.gov (United States)

    Manago, Francesca; Castellano, Claudio; Oliverio, Alberto; Mele, Andrea; De Leonibus, Elvira

    2009-01-01

    Recent evidence demonstrated that dopamine within the nucleus accumbens mediates consolidation of both associative and nonassociative memories. However, the specific contribution of the nucleus accumbens subregions, core and shell, and of D1 and D2 receptors subtypes has not been yet clarified. The aim of this study was, therefore, to directly…

  13. Role of Dopamine Receptors Subtypes, D1-Like and D2-Like, within the Nucleus Accumbens Subregions, Core and Shell, on Memory Consolidation in the One-Trial Inhibitory Avoidance Task

    Science.gov (United States)

    Manago, Francesca; Castellano, Claudio; Oliverio, Alberto; Mele, Andrea; De Leonibus, Elvira

    2009-01-01

    Recent evidence demonstrated that dopamine within the nucleus accumbens mediates consolidation of both associative and nonassociative memories. However, the specific contribution of the nucleus accumbens subregions, core and shell, and of D1 and D2 receptors subtypes has not been yet clarified. The aim of this study was, therefore, to directly…

  14. Music-dependent memory in immediate and delayed word recall.

    Science.gov (United States)

    Balch, W R; Bowman, K; Mohler, L

    1992-01-01

    Undergraduate volunteers rated a series of words for pleasantness while hearing a particular background music. The subjects in Experiment 1 received, immediately or after a 48-h delay, an unexpected word-recall test in one of the following musical cue contexts: same cue (S), different cue (D), or no cue (N). For immediate recall, context dependency (S-D) was significant but same-cue facilitation (S-N) was not. No cue effects at all were found for delayed recall, and there was a significant interaction between cue and retention interval. A similar interaction was also found in Experiment 3, which was designed to rule out an alternative explanation with respect to distraction. When the different musical selection was changed specifically in either tempo or form (genre), only pieces having an altered tempo produced significantly lower immediate recall compared with the same pieces (Experiment 2). The results support a stimulus generalization view of music-dependent memory.

  15. To Replay, Perchance to Consolidate.

    Directory of Open Access Journals (Sweden)

    Lisa Genzel

    2015-10-01

    Full Text Available After a memory is formed, it continues to be processed by the brain. These "off-line" processes consolidate the memory, leading to its enhancement and to changes in memory circuits. Potentially, these memory changes are driven by off-line replay of the pattern of neuronal activity present when the memory was being formed. A new study by Dhaksin Ramanathan and colleagues, published in PLOS Biology, demonstrates that replay occurs predominately after the acquisition of a new motor skill and that it is related to changes in memory performance and to the subsequent changes in memory circuits. Together, these observations reveal the importance of neuronal replay in the consolidation of novel motor skills.

  16. Time-course of 5-HT(6) receptor mRNA expression during memory consolidation and amnesia.

    Science.gov (United States)

    Huerta-Rivas, A; Pérez-García, G; González-Espinosa, C; Meneses, A

    2010-01-01

    Growing evidence indicates that antagonists of the 5-hydroxytryptamine (serotonin) receptor(6) (5-HT(6)) improve memory and reverse amnesia although the mechanisms involved are poorly understood. Hence, in this paper RT-PCR was used to evaluate changes in mRNA expression of 5-HT(6) receptor in trained and untrained rats treated with the 5-HT(6) receptor antagonist SB-399885 and amnesic drugs scopolamine or dizocilpine. Changes in mRNA expression of 5-HT(6) receptor were investigated at different times in prefrontal cortex, hippocampus and striatum. Data indicated that memory in the Pavlovian/instrumental autoshaping task was a progressive process associated to reduced mRNA expression of 5-HT(6) receptor in the three structures examined. SB-399885 improved long-term memory at 48h, while the muscarinic receptor antagonist scopolamine or the non-competitive NMDA receptor antagonist dizocilpine impaired it at 24h. Autoshaping training and treatment with SB-399885 increased 5-HT(6) receptor mRNA expression in (maximum increase) prefrontal cortex and striatum, 24 or 48h. The scopolamine-induced amnesia suppressed 5-HT(6) receptor mRNA expression while the dizocilpine-induced amnesia did not modify 5-HT(6) receptor mRNA expression. SB-399885 and scopolamine or dizocilpine were able to reestablish memory and 5-HT(6) receptor mRNA expression. These data confirmed previous memory evidence and of more interest is the observation that training, SB-399885 and amnesic drugs modulated 5-HT(6) receptor mRNA expression in prefrontal cortex, hippocampus and striatum. Further investigation in different memory tasks, times and amnesia models together with more complex control groups might provide further clues.

  17. Dreams are made of memories, but maybe not for memory.

    Science.gov (United States)

    Blagrove, Mark; Ruby, Perrine; Eichenlaub, Jean-Baptiste

    2013-12-01

    Llewellyn's claim that rapid eye movement (REM) dream imagery may be related to the processes involved in memory consolidation during sleep is plausible. However, whereas there is voluntary and deliberate intention behind the construction of images in the ancient art of memory (AAOM) method, there is a lack of intentionality in producing dream images. The memory for dreams is also fragile, and dependent on encoding once awake.

  18. Activation of PKCzeta and PKMzeta in the nucleus accumbens core is necessary for the retrieval, consolidation and reconsolidation of drug memory.

    Directory of Open Access Journals (Sweden)

    Jose A Crespo

    Full Text Available One of the greatest challenges in the treatment of substance dependence is to reverse the control that drug-associated stimuli have gained over the addict's behavior, as these drug-associated memories increase the risk of relapse even after long periods of abstinence. We report here that inhibition of the atypical protein kinase C isoform PKCzeta and its constitutively active isoform PKMzeta with the pseudosubstrate inhibitor ZIP administered locally into the nucleus accumbens core reversibly inhibited the retrieval of drug-associated memory and drug (remifentanil seeking, whereas a scrambled ZIP peptide or staurosporine, an effective inhibitor of c/nPKC-, CaMKII-, and PKA kinases that does not affect PKCzeta/PKMzeta activity, was without effect on these memory processes. Acquisition or extinction of drug-associated memory remained unaffected by PKCzeta- and PKMzeta inhibition.

  19. Scaling dependence of memory windows and different carrier charging behaviors in Si nanocrystal nonvolatile memory devices

    Science.gov (United States)

    Yu, Jie; Chen, Kun-ji; Ma, Zhong-yuan; Zhang, Xin-xin; Jiang, Xiao-fan; Wu, Yang-qing; Huang, Xin-fan; Oda, Shunri

    2016-09-01

    Based on the charge storage mode, it is important to investigate the scaling dependence of memory performance in silicon nanocrystal (Si-NC) nonvolatile memory (NVM) devices for its scaling down limit. In this work, we made eight kinds of test key cells with different gate widths and lengths by 0.13-μm node complementary metal oxide semiconductor (CMOS) technology. It is found that the memory windows of eight kinds of test key cells are almost the same of about 1.64 V @ ± 7 V/1 ms, which are independent of the gate area, but mainly determined by the average size (12 nm) and areal density (1.8 × 1011/cm2) of Si-NCs. The program/erase (P/E) speed characteristics are almost independent of gate widths and lengths. However, the erase speed is faster than the program speed of test key cells, which is due to the different charging behaviors between electrons and holes during the operation processes. Furthermore, the data retention characteristic is also independent of the gate area. Our findings are useful for further scaling down of Si-NC NVM devices to improve the performance and on-chip integration. Project supported by the State Key Development Program for Basic Research of China (Grant No. 2010CB934402) and the National Natural Science Foundation of China (Grant Nos. 11374153, 61571221, and 61071008).

  20. Temperature Dependency of Water Vapor Permeability of Shape Memory Polyurethane

    Institute of Scientific and Technical Information of China (English)

    ZENG Yue-min; HU Jin-lian; YAN Hao-jing

    2002-01-01

    Solution-cast films of shape memory polyurethane have beea investigated. Differential scanning calorimetry,DMA, tensile test, water vapor permeability and the shape merry effect were carried out to characterize these polyurethane membranes. Samples cast at higher temperatures contained more hard segment in the crystalline state than a sample cast at lower temperature. The change in the water vapor permeability (WVP) of SMPU films with respect to the temperature follows an S- shaped curve, and increases abruptly at Tm of the soft segment for the fractional free volume (FFV, the ratio of free volume and specific volume in polymers) increased linearly with temperature. The water vapor permeability dependency of the temperature and humidity contribute to the result of the change of diffusion and solubility with the surrounding air condition. The diffusion coefficient (D)are the function of temperature and show good fit the Arrhenius form but show different parameter values when above and below Tg. The crystalline state hardsegment is necessary for the good shape memory effect.

  1. Time-dependent effects of cortisol on the contextualization of emotional memories.

    Science.gov (United States)

    van Ast, Vanessa A; Cornelisse, Sandra; Meeter, Martijn; Joëls, Marian; Kindt, Merel

    2013-12-01

    The inability to store fearful memories into their original encoding context is considered to be an important vulnerability factor for the development of anxiety disorders like posttraumatic stress disorder. Altered memory contextualization most likely involves effects of the stress hormone cortisol, acting via receptors located in the memory neurocircuitry. Cortisol via these receptors induces rapid nongenomic effects followed by slower genomic effects, which are thought to modulate cognitive function in opposite, complementary ways. Here, we targeted these time-dependent effects of cortisol during memory encoding and tested subsequent contextualization of emotional and neutral memories. In a double-blind, placebo-controlled design, 64 men were randomly assigned to one of three groups: 1) received 10 mg hydrocortisone 30 minutes (rapid cortisol effects) before a memory encoding task; 2) received 10 mg hydrocortisone 210 minutes (slow cortisol) before a memory encoding task; or 3) received placebo at both times. During encoding, participants were presented with neutral and emotional words in unique background pictures. Approximately 24 hours later, context dependency of their memories was assessed. Recognition data revealed that cortisol's rapid effects impair emotional memory contextualization, while cortisol's slow effects enhance it. Neutral memory contextualization remained unaltered by cortisol, irrespective of the timing of the drug. This study shows distinct time-dependent effects of cortisol on the contextualization of specifically emotional memories. The results suggest that rapid effects of cortisol may lead to impaired emotional memory contextualization, while slow effects of cortisol may confer protection against emotional memory generalization. © 2013 Society of Biological Psychiatry.

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

    Science.gov (United States)

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

    2014-01-01

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

  3. Context-dependent enhancement of declarative memory performance following acute psychosocial stress.

    Science.gov (United States)

    Smeets, T; Giesbrecht, T; Jelicic, M; Merckelbach, H

    2007-09-01

    Studies on how acute stress affects learning and memory have yielded inconsistent findings, with some studies reporting enhancing effects while others report impairing effects. Recently, Joëls et al. [Joëls, M., Pu, Z., Wiegert, O., Oitzl, M.S., Krugers, H.J., 2006. Learning under stress: how does it work? Trends in Cognitive Sciences, 10, 152-158] argued that stress will enhance memory only when the memory acquisition phase and stressor share the same spatiotemporal context (i.e., context-congruency). The current study tested this hypothesis by looking at whether context-congruent stress enhances declarative memory performance. Undergraduates were assigned to a personality stress group (n=16), a memory stress group (n=18), or a no-stress control group (n=18). While being exposed to the acute stressor or a control task, participants encoded personality- and memory-related words and were tested for free recall 24h later. Relative to controls, stress significantly enhanced recall of context-congruent words, but only for personality words. This suggests that acute stress may strengthen the consolidation of memory material when the stressor matches the to-be-remembered information in place and time.

  4. Disruption of the dorsolateral prefrontal cortex facilitates the consolidation of procedural skills.

    Science.gov (United States)

    Galea, Joseph M; Albert, Neil B; Ditye, Thomas; Miall, R Chris

    2010-06-01

    In explicit sequence learning tasks, an improvement in performance (skill) typically occurs after sleep-leading to the recent literature on sleep-dependent motor consolidation. Consolidation can also be facilitated during wakefulness if declarative knowledge for the sequence is reduced through a secondary cognitive task. Accordingly, declarative and procedural consolidation processes appear to mutually interact. Here we used TMS to test the hypothesis that functions in the dorsolateral prefrontal cortex (DLPFC) that support declarative memory formation indirectly reduce the formation of procedural representations. We hypothesize that disrupting the DLPFC immediately after sequence learning would degrade the retention or the consolidation of the sequence within the declarative memory system and thus facilitate consolidation within procedural memory systems, evident as wakeful off-line skill improvement. Inhibitory theta-burst TMS was applied to the left DLPFC (n = 10), to the right DLPFC (n = 10), or to an occipital cortical control site (n = 10) immediately after training on the serial reaction time task (SRTT). All groups were retested after eight daytime hours without sleep. TMS of either left or right DLPFC lead to skill improvements on the SRTT. Increase in skill was greater following right DLPFC stimulation than left DLPFC stimulation; there was no improvement in skill for the control group. Across all participants, free recall of the sequence was inversely related to the improvements in performance on the SRTT. These results support the hypothesis of interference between declarative and procedural consolidation processes and are discussed in the framework of the interactions between memory systems.

  5. Involvement of actin rearrangements within the amygdala and the dorsal hippocampus in aversive memories of drug withdrawal in acute morphine-dependent rats.

    Science.gov (United States)

    Hou, Yuan-Yuan; Lu, Bin; Li, Mu; Liu, Yao; Chen, Jie; Chi, Zhi-Qiang; Liu, Jing-Gen

    2009-09-30

    Aversive memories of drug withdrawal can generate a motivational state leading to compulsive drug taking. Changes in synaptic plasticity may be involved in the formation of aversive memories. Dynamic rearrangement of the cytoskeletal actin, a major structural component of the dendritic spine, regulates synaptic plasticity. Here, the potential involvement of actin rearrangements in the induction of aversive memories of morphine withdrawal was examined. We found that lesions of the amygdala or dorsal hippocampus (DH) but not nucleus accumbens (NAc) impaired conditioned place aversion (CPA) of acute morphine-dependent rats. Accordingly, conditioned morphine withdrawal induced actin rearrangements in the amygdala and the DH but not in the NAc. In addition, we found that conditioned morphine withdrawal also increased activity-regulated cytoskeletal-associated protein (Arc) expression in the amygdala but not in the DH, although actin rearrangements were observed in both areas. We further found that inhibition of actin rearrangements by intra-amygdala or intra-DH injections of latrunculin A, an inhibitor of actin polymerization, significantly attenuated CPA. Furthermore, we found that manipulation of amygdala beta-adrenoceptor activity by its antagonist propranolol and agonist clenbuterol differentially altered actin rearrangements in the DH. Therefore, our findings reveal that actin rearrangements in the amygdala and the DH are required for the acquisition and consolidation of the aversive memories of drug withdrawal and that the beta-noradrenergic system within the amygdala modulates aversive memory consolidation by regulating actin rearrangements but not Arc protein expression in the DH, which is distinct from its role in modulation of inhibitory avoidance memory.

  6. Implicit and Explicit Memory Bias in Opiate Dependent, Abstinent and Normal Individuals

    Directory of Open Access Journals (Sweden)

    Jafar Hasani

    2013-07-01

    Full Text Available Objective: The aim of current research was to assess implicit and explicit memory bias to drug related stimuli in opiate Dependent, abstinent and normal Individuals. Method: Three groups including opiate Dependent, abstinent and normal Individuals (n=25 were selected by available sampling method. After matching on the base of age, education level and type of substance use all participants assessed by recognition task (explicit memory bias and stem completion task (implicit memory bias. Results: The analysis of data showed that opiate dependent and abstinent groups in comparison with normal individual had implicit memory bias, whereas in explicit memory only opiate dependent individuals showed bias. Conclusion: The identification of explicit and implicit memory governing addiction may have practical implications in diagnosis, treatment and prevention of substance abuse.

  7. Role of NPY Y1 receptor on acquisition, consolidation and extinction on contextual fear conditioning: dissociation between anxiety, locomotion and non-emotional memory behavior.

    Science.gov (United States)

    Lach, Gilliard; de Lima, Thereza Christina Monteiro

    2013-07-01

    Neuropeptide Y (NPY) is the most abundant peptide in the central nervous system (CNS) and is densely localized in the brain regions involved in stress, memory, fear and anxiety. Although previous research supports a role for NPY in the mediation of rodent and human emotional behavior, there is currently a lack of information on the effects of low doses of NPY that could have a potential therapeutic advantage, minimizing side-effects such as cognition impairment or sedation. Herein, we assessed the effects of intracerebroventricular (i.c.v.) administration of low doses of NPY, and of the Y1-agonist Leu31Pro34-NPY (LP-NPY) on contextual fear conditioning (CFC), as they have no effect on unconditioned anxiety-like, locomotor activity and non-emotional memory. NPY (3 pmol) and LP-NPY (1 pmol) inhibited freezing behavior when administered in the acquisition or consolidation stages, indicating a reduction of fear. When injected in the extinction phase, only NPY inhibited freezing behavior on CFC. Pre-treatment with the Y1-antagonist BIBO3304 before NPY and LP-NPY was able to prevent the inhibition of fear responses induced by both NPY agonists. Taken together, our results demonstrate robust fear-inhibiting effects of i.c.v. injection of NPY on contextual fear conditioning in rats, a response that is mediated, at least in part, by the Y1 receptor. Moreover, these treatments were unable to change locomotor activity or to show an anxiolytic-like effect, as evaluated in an open-field and an elevated plus-maze. This specific fear reduction effect may underlie resilience systems in the CNS and has potential therapeutic relevance in PTSD.

  8. Sex differences in HIV effects on visual memory among substance-dependent individuals.

    Science.gov (United States)

    Keutmann, Michael K; Gonzalez, Raul; Maki, Pauline M; Rubin, Leah H; Vassileva, Jasmin; Martin, Eileen M

    2016-11-13

    HIV's effects on episodic memory have not been compared systematically between male and female substance-dependent individuals. We administered the Brief Visuospatial Memory Test-Revised (BVMT-R) to 280 substance-dependent HIV+ and HIV- men and women. Groups were comparable on demographic, substance use, and comorbid characteristics. There were no significant main effects of sex or HIV serostatus on BVMT-R performance, but HIV+ women performed significantly more poorly on delayed recall. This effect was most prominent among cocaine-dependent HIV+ women. Our findings are consistent with recent speculation that memory impairment may be more common among HIV+ women, particularly those with a history of cocaine dependence.

  9. Synaptic consolidation across multiple timescales

    Directory of Open Access Journals (Sweden)

    Lorric Ziegler

    2014-03-01

    Full Text Available The brain is bombarded with a continuous stream of sensory events, but retains only a small subset in memory. The selectivity of memory formation prevents our memory from being overloaded with irrelevant items that would rapidly bring the brain to its storage limit; moreover, selectivity also prevents overwriting previously formed memories with new ones. Memory formation in the hippocampus, as well as in other brain regions, is thought to be linked to changes in the synaptic connections between neurons. In this view, sensory events imprint traces at the level of synapses that reflect potential memory items. The question of memory selectivity can therefore be reformulated as follows: what are the reasons and conditions that some synaptic traces fade away whereas others are consolidated and persist? Experimentally, changes in synaptic strength induced by 'Hebbian' protocols fade away over a few hours (early long-term potentiation or e-LTP, unless these changes are consolidated. The experiments and conceptual theory of synaptic tagging and capture (STC provide a mechanistic explanation for the processes involved in consolidation. This theory suggests that the initial trace of synaptic plasticity sets a tag at the synapse, which then serves as a marker for potential consolidation of the changes in synaptic efficacy. The actual consolidation processes, transforming e-LTP into late LTP (l-LTP, require the capture of plasticity-related proteins (PRP. We translate the above conceptual model into a compact computational model that accounts for a wealth of in vitro data including experiments on cross-tagging, tag-resetting and depotentiation. A central ingredient is that synaptic traces are described with several variables that evolve on different time scales. Consolidation requires the transmission of information from a 'fast' synaptic trace to a 'slow' one through a 'write' process, including the formation of tags and the production of PRP for the

  10. Sleep and memory in the making. Are current concepts sufficient in children?

    Science.gov (United States)

    Peigneux, P

    2014-01-01

    Memory consolidation is an active process wired in brain plasticity. How plasticity mechanisms develop and are modulated after learning is at the core of current models of sleep-dependent memory consolidation. Nowadays, two main classes of sleep-related memory consolidation theories are proposed, namely system consolidation and synaptic homeostasis. However, novel models of consolidation emerge, that might better account for the highly dynamic and interactive processes of encoding and memory consolidation. Processing steps can take place at various temporal phases and be modulated by interactions with prior experiences and ongoing events. In this perspective, sleep might support (or not) memory consolidation processes under specific neurophysiological and environmental circumstances leading to enduring representations in long-term memory stores. We outline here a discussion about how current and emergent models account for the complexity and apparent inconsistency of empirical data. Additionally, models aimed at understanding neurophysiological and/or cognitive processes should not only provide a satisfactory explanation for the phenomena at stake, but also account for their ontogeny and the conditions that disrupt their organisation. Looking at the available literature, this developmental condition appears to remain unfulfilled when trying to understand the relationships between sleep, learning and memory consolidation processes, both in healthy children and in children with pathological conditions.

  11. Distinct T helper cell dependence of memory B-cell proliferation versus plasma cell differentiation.

    Science.gov (United States)

    Zabel, Franziska; Fettelschoss, Antonia; Vogel, Monique; Johansen, Pål; Kündig, Thomas M; Bachmann, Martin F

    2017-03-01

    Several memory B-cell subclasses with distinct functions have been described, of which the most effective is the class-switched (CS) memory B-cell population. We have previously shown, using virus-like particles (VLPs), that the proliferative potential of these CS memory B cells is limited and they fail to re-enter germinal centres (GCs). However, VLP-specific memory B cells quickly differentiated into secondary plasma cells (PCs) with the virtue of elevated antibody production compared with primary PCs. Whereas the induction of VLP(+) memory B cells was strongly dependent on T helper cells, we were wondering whether re-stimulation of VLP(+) memory B cells and their differentiation into secondary PCs would also require T helper cells. Global absence of T helper cells led to strongly impaired memory B cell proliferation and PC differentiation. In contrast, lack of interleukin-21 receptor-dependent follicular T helper cells or CD40 ligand signalling strongly affected proliferation of memory B cells, but differentiation into mature secondary PCs exhibiting increased antibody production was essentially normal. This contrasts with primary B-cell responses, where a strong dependence on CD40 ligand but limited importance of interleukin-21 receptor was seen. Hence, T helper cell dependence differs between primary and secondary B-cell responses as well as between memory B-cell proliferation and PC differentiation.

  12. Either the dorsal hippocampus or the dorsolateral striatum is selectively involved in consolidation of forced swim-induced immobility depending on genetic background.

    Science.gov (United States)

    Colelli, V; Campus, P; Conversi, D; Orsini, C; Cabib, S

    2014-05-01

    Healthy subjects differ in the memory system they engage to learn dual-solution tasks. Both genotype and stress experience could contribute to this phenotypic variability. The present experiments tested whether the hippocampus and the dorsal striatum, the core nodes of two different memory systems, are differently involved in 24 h retention of a stress-associated memory in two genetically unrelated inbred strains of mice. Mice from both the C57BL/6J and the DBA/2J inbred strains showed progressive increase of immobility during 10 min exposure to forced swim (FS) and retrieved the acquired levels of immobility when tested 24h later. The pattern of c-fos immunostaining promoted by FS revealed activation of a large number of brain areas in both strains, including CA1 and CA3 fields of the hippocampus. However, only DBA/2J mice showed activation of the dorsolateral striatum (DLS). In addition, FS induced a positive correlation between c-fos expression in the amygdala and CA1 and CA3 in C57BL/6J mice whereas it induced a positive correlation between c-fos expression in the amygdala and DLS in DBA/2J mice. Finally, temporary post-training inactivation of the dorsal hippocampus, by local infusion of lidocaine, prevented 24h retention of immobility in C57BL/6J mice only, whereas inactivation of the DLS prevented retention in DBA/2J mice only. These findings support the view that genetic factors can determine whether the dorsal hippocampus or the DLS are selectively engaged to consolidate stress-related memory.

  13. Dose-dependent effects of hydrocortisone infusion on autobiographical memory recall.

    Science.gov (United States)

    Young, Kymberly; Drevets, Wayne C; Schulkin, Jay; Erickson, Kristine

    2011-10-01

    The glucocorticoid hormone cortisol has been shown to impair episodic memory performance. The present study examined the effect of two doses of hydrocortisone (synthetic cortisol) administration on autobiographical memory retrieval. Healthy volunteers (n = 66) were studied on two separate visits, during which they received placebo and either moderate-dose (0.15 mg/kg IV; n = 33) or high-dose (0.45 mg/kg IV; n = 33) hydrocortisone infusion. From 75 to 150 min post-infusion subjects performed an Autobiographical Memory Test and the California Verbal Learning Test (CVLT). The high-dose hydrocortisone administration reduced the percent of specific memories recalled (p = .04), increased the percent of categorical (nonspecific) memories recalled (p cortisol affects accessibility of autobiographical memories in a dose-dependent manner. Specifically, administration of hydrocortisone at doses analogous to those achieved under severe psychosocial stress impaired the specificity and speed of retrieval of autobiographical memories.

  14. State-dependent effect of dopamine D₁/D₅ receptors inactivation on memory destabilization and reconsolidation.

    Science.gov (United States)

    Rossato, Janine I; Köhler, Cristiano A; Radiske, Andressa; Lima, Ramón H; Bevilaqua, Lia R M; Cammarota, Martín

    2015-05-15

    Object recognition memories (ORM) can incorporate new information upon reactivation. This update initially involves destabilization of the original memory, which is followed by restabilization of the upgraded engram through a reconsolidation process that requires gene expression and protein synthesis in the hippocampus. We found that when given in dorsal CA1 either immediately after training or 15 min before ORM reactivation in the presence of a novel object, the dopamine D1/D5 receptor antagonist SCH23390 did not affect ORM consolidation, expression or retention but impeded the amnesia caused by the post-retrieval administration of the mRNA synthesis inhibitor α-amanitin or the protein synthesis blocker anisomycin. This anti-amnesic effect was not observed when SCH23390 was given immediately after training and again 15 min before memory reactivation. Our results demonstrate that hippocampal D1/D5 receptors are not needed for formation, retrieval or post-retrieval restabilization of the ORM trace but are essential for its destabilization when reactivation occurs together with the incorporation of new information into the original memory. Importantly, they also suggest that reenactment of the animal's post-learning neurochemical milieu at the moment of memory reactivation can be a boundary condition for reconsolidation.

  15. Treadmill Exercise Improves Memory Function Depending on Circadian Rhythm Changes in Mice

    OpenAIRE

    Hwang, Dong Sup; Kwak, Hyo Bum; Ko, Il Gyu; Kim, Sung Eun; Jin, Jun Jang; Ji, Eun Sang; Choi, Hyun Hee; Kwon, Oh Young

    2016-01-01

    Purpose Exercise enhances memory function by increasing neurogenesis in the hippocampus, and circadian rhythms modulate synaptic plasticity in the hippocampus. The circadian rhythm-dependent effects of treadmill exercise on memory function in relation with neurogenesis were investigated using mice. Methods The step-down avoidance test was used to evaluate short-term memory, the 8-arm maze test was used to test spatial learning ability, and 5-bromo-2’-deoxyuridine immunofluorescence was used t...

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

    Science.gov (United States)

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

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  18. Sleep deprivation during a specific 3-hour time window post-training impairs hippocampal synaptic plasticity and memory

    OpenAIRE

    Prince, Toni-Moi; Wimmer, Mathieu; Choi, Jennifer; Havekes, Robbert; Aton, Sara; Abel, Ted

    2013-01-01

    Sleep deprivation disrupts hippocampal function and plasticity. In particular, long-term memory consolidation is impaired by sleep deprivation, suggesting that a specific critical period exists following learning during which sleep is necessary. To elucidate the impact of sleep deprivation on long-term memory consolidation and synaptic plasticity, long-term memory was assessed when mice were sleep deprived following training in the hippocampus-dependent object place recognition task. We found...

  19. Sleep and memory in mammals, birds and invertebrates.

    Science.gov (United States)

    Vorster, Albrecht P; Born, Jan

    2015-03-01

    Sleep supports memory consolidation. Based on studies in mammals, sleep-dependent consolidation has been conceptualized as 'active system consolidation'. During waking, information is encoded into an initial store (hippocampus). During subsequent sleep, some of the newly encoded memories are selected to be reactivated and redistributed toward networks serving as long-term store (e.g., neocortex), whereby memories become transformed into more general, schema-like representations. Here we asked whether sleep in non-mammalian species might play a comparable role for memory. The literature review revealed that sleep produces enhancing effects on memory in all non-mammalian species studied. Furthermore, across species some of the hallmarking features of active system consolidation were identified: Studies of filial imprinting in chicks suggest that a redistribution of imprinting memory toward long-term storage sites occurs during sleep; song learning in birds appears to be driven by reactivations of song representations during sleep; studies of bees demonstrated the selectivity of sleep-dependent consolidation, benefiting extinction but not original classical conditioning. Although overall fragmentary, first evidence in non-mammalian species suggests active system consolidation might be an evolutionary conserved function of sleep. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  20. Tramadol state-dependent memory: involvement of dorsal hippocampal muscarinic acetylcholine receptors.

    Science.gov (United States)

    Jafari-Sabet, Majid; Jafari-Sabet, Ali-Reza; Dizaji-Ghadim, Ali

    2016-08-01

    The effects on tramadol state-dependent memory of bilateral intradorsal hippocampal (intra-CA1) injections of physostigmine, an acetylcholinesterase inhibitor, and atropine, a muscarinic acetylcholine receptor antagonist, were examined in adult male NMRI mice. A single-trial step-down passive avoidance task was used for the assessment of memory retention. Post-training intra-CA1 administration of an atypical μ-opioid receptor agonist, tramadol (0.5 and 1 μg/mouse), dose dependently impaired memory retention. Pretest injection of tramadol (0.5 and 1 μg/mouse, intra-CA1) induced state-dependent retrieval of the memory acquired under the influence of post-training tramadol (1 μg/mouse, intra-CA1). A pretest intra-CA1 injection of physostigmine (1 μg/mouse) reversed the memory impairment induced by post-training administration of tramadol (1 μg/mouse, intra-CA1). Moreover, pretest administration of physostigmine (0.5 and 1 μg/mouse, intra-CA1) with an ineffective dose of tramadol (0.25 μg/mouse, intra-CA1) also significantly restored retrieval. Pretest administration of physostigmine (0.25, 0.5, and 1 μg/mouse, intra-CA1) by itself did not affect memory retention. A pretest intra-CA1 injection of the atropine (1 and 2 μg/mouse) 5 min before the administration of tramadol (1 μg/mouse, intra-CA1) dose dependently inhibited tramadol state-dependent memory. Pretest administration of atropine (0.5, 1, and 2 μg/mouse, intra-CA1) by itself did not affect memory retention. It can be concluded that dorsal hippocampal muscarinic acetylcholine receptor mechanisms play an important role in the modulation of tramadol state-dependent memory.

  1. Time-dependent enhancement of hippocampus-dependent memory after treatment with memantine: Implications for enhanced hippocampal adult neurogenesis.

    Science.gov (United States)

    Ishikawa, Rie; Kim, Ryang; Namba, Takashi; Kohsaka, Shinichi; Uchino, Shigeo; Kida, Satoshi

    2014-07-01

    Adult hippocampal neurogenesis has been suggested to play modulatory roles in learning and memory. Importantly, previous studies have shown that newborn neurons in the adult hippocampus are integrated into the dentate gyrus circuit and are recruited more efficiently into the hippocampal memory trace of mice when they become 3 weeks old. Interestingly, a single high-dose treatment with the N-methyl-d-aspartate receptor antagonist memantine (MEM) has been shown to increase hippocampal neurogenesis dramatically by promoting cell proliferation. In the present study, to understand the impact of increased adult neurogenesis on memory performance, we examined the effects of a single treatment of MEM on hippocampus-dependent memory in mice. Interestingly, mice treated with MEM showed an improvement of hippocampus-dependent spatial and social recognition memories when they were trained and tested at 3-6 weeks, but not at 3 days or 4 months, after treatment with MEM. Importantly, we observed a significant positive correlation between the scores for spatial memory (probe trial in the Morris water maze task) and the number of young mature neurons (3 weeks old) in MEM-treated mice, but not saline-treated mice. We also observed that the young mature neurons generated by treatment with MEM were recruited into the trace of spatial memory similarly to those generated through endogenous neurogenesis. Taken together, our observations suggest that treatment with MEM temporally improves hippocampus-dependent memory formation and that the newborn neurons increased by treatment with MEM contribute to this improvement when they become 3 weeks old. © 2014 Wiley Periodicals, Inc.

  2. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; de Oliveira Alvares, Lucas

    2016-01-01

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca2+ channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca2+ influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time. PMID:26947131

  3. Forgetting of long-term memory requires activation of NMDA receptors, L-type voltage-dependent Ca2+ channels, and calcineurin.

    Science.gov (United States)

    Sachser, Ricardo Marcelo; Santana, Fabiana; Crestani, Ana Paula; Lunardi, Paula; Pedraza, Lizeth Katherine; Quillfeldt, Jorge Alberto; Hardt, Oliver; Alvares, Lucas de Oliveira

    2016-03-07

    In the past decades, the cellular and molecular mechanisms underlying memory consolidation, reconsolidation, and extinction have been well characterized. However, the neurobiological underpinnings of forgetting processes remain to be elucidated. Here we used behavioral, pharmacological and electrophysiological approaches to explore mechanisms controlling forgetting. We found that post-acquisition chronic inhibition of the N-methyl-D-aspartate receptor (NMDAR), L-type voltage-dependent Ca(2+) channel (LVDCC), and protein phosphatase calcineurin (CaN), maintains long-term object location memory that otherwise would have been forgotten. We further show that NMDAR activation is necessary to induce forgetting of object recognition memory. Studying the role of NMDAR activation in the decay of the early phase of long-term potentiation (E-LTP) in the hippocampus, we found that ifenprodil infused 30 min after LTP induction in vivo blocks the decay of CA1-evoked postsynaptic plasticity, suggesting that GluN2B-containing NMDARs activation are critical to promote LTP decay. Taken together, these findings indicate that a well-regulated forgetting process, initiated by Ca(2+) influx through LVDCCs and GluN2B-NMDARs followed by CaN activation, controls the maintenance of hippocampal LTP and long-term memories over time.

  4. 老化对睡眠依赖性记忆巩固的影响%Sleep-dependent Memory Consolidation:The Effect of Aging

    Institute of Scientific and Technical Information of China (English)

    贵文君; 雷旭; 袁宏; 高东; 喻婧

    2015-01-01

    Along with the aging processing, the changes of sleep and sleep-dependent memory consolidation (SDC) become prominent in older adults. Although prior research indicated that the beneficial effect of sleep on procedural memory consolidation was reduced in older adults, it is still unclear whether they also show impairments on declarative memory. In addition, compared to normal controls, individuals who have neurodegeneration disorders showed impaired SDC effect on episodic memory. Future studies need to consider using both EEG and fMRI data to explore the neural pathway of aging effects on memory through sleep and to investigate the interaction among aging, sleep and memory. Also, it is important to examine the intervention effects on older adults' memory through sleep.%随着老化的发生和发展,老年人的睡眠和记忆问题变得越来越突出。研究显示老年人针对程序性记忆的睡眠依赖性巩固能力受损,而针对陈述性记忆的睡眠依赖性巩固研究结果尚存分歧。此外,患有神经退行性疾病的老年人在正常老化的基础上伴有情景记忆睡眠依赖性巩固能力受损。未来研究应考虑同步采集脑电和脑成像数据,探索增龄通过睡眠影响记忆的神经通路,尝试搭建老化、睡眠以及记忆三因素的交互模型,并从睡眠对记忆巩固影响的角度提出针对老年人记忆问题的干预措施。

  5. On the Relationship between Memory and Perception: Sequential Dependencies in Recognition Memory Testing

    Science.gov (United States)

    Malmberg, Kenneth J.; Annis, Jeffrey

    2012-01-01

    Many models of recognition are derived from models originally applied to perception tasks, which assume that decisions from trial to trial are independent. While the independence assumption is violated for many perception tasks, we present the results of several experiments intended to relate memory and perception by exploring sequential…

  6. Chronic Stress Impairs Prefrontal Cortex-Dependent Response Inhibition and Spatial Working Memory

    Science.gov (United States)

    Mika, Agnieszka; Mazur, Gabriel J.; Hoffman, Ann N.; Talboom, Joshua S.; Bimonte-Nelson, Heather A.; Sanabria, Federico; Conrad, Cheryl D.

    2012-01-01

    Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague Dawley rats were first trained on the RAWM and subsequently trained on FMI. Following acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when food reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing precision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher’s r to z transformation revealed no significant differences between control and stress with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been direct compared within the same animals following chronic stress, using FMI, an appetitive task, and RAWM, a non-appetitive task. PMID:22905921

  7. Chronic stress impairs prefrontal cortex-dependent response inhibition and spatial working memory.

    Science.gov (United States)

    Mika, Agnieszka; Mazur, Gabriel J; Hoffman, Ann N; Talboom, Joshua S; Bimonte-Nelson, Heather A; Sanabria, Federico; Conrad, Cheryl D

    2012-10-01

    Chronic stress leads to neurochemical and structural alterations in the prefrontal cortex (PFC) that correspond to deficits in PFC-mediated behaviors. The present study examined the effects of chronic restraint stress on response inhibition (using a response-withholding task, the fixed-minimum interval schedule of reinforcement, or FMI), and working memory (using a radial arm water maze, RAWM). Adult male Sprague-Dawley rats were first trained on the RAWM and subsequently trained on FMI. After acquisition of FMI, rats were assigned to a restraint stress (6h/d/28d in wire mesh restrainers) or control condition. Immediately after chronic stress, rats were tested on FMI and subsequently on RAWM. FMI results suggest that chronic stress reduces response inhibition capacity and motivation to initiate the task on selective conditions when sucrose reward was not obtained on the preceding trial. RAWM results suggest that chronic stress produces transient deficits in working memory without altering previously consolidated reference memory. Behavioral measures from FMI failed to correlate with metrics from RAWM except for one in which changes in FMI timing imprecision negatively correlated with changes in RAWM working memory errors for the controls, a finding that was not observed following chronic stress. Fisher's r-to-z transformation revealed no significant differences between control and stress groups with correlation coefficients. These findings are the first to show that chronic stress impairs both response inhibition and working memory, two behaviors that have never been directly compared within the same animals after chronic stress, using FMI, an appetitive task, and RAWM, a nonappetitive task.

  8. Uncertainty-Dependent Extinction of Fear Memory in an Amygdala-mPFC Neural Circuit Model

    Science.gov (United States)

    Li, Yuzhe; Nakae, Ken; Ishii, Shin; Naoki, Honda

    2016-01-01

    Uncertainty of fear conditioning is crucial for the acquisition and extinction of fear memory. Fear memory acquired through partial pairings of a conditioned stimulus (CS) and an unconditioned stimulus (US) is more resistant to extinction than that acquired through full pairings; this effect is known as the partial reinforcement extinction effect (PREE). Although the PREE has been explained by psychological theories, the neural mechanisms underlying the PREE remain largely unclear. Here, we developed a neural circuit model based on three distinct types of neurons (fear, persistent and extinction neurons) in the amygdala and medial prefrontal cortex (mPFC). In the model, the fear, persistent and extinction neurons encode predictions of net severity, of unconditioned stimulus (US) intensity, and of net safety, respectively. Our simulation successfully reproduces the PREE. We revealed that unpredictability of the US during extinction was represented by the combined responses of the three types of neurons, which are critical for the PREE. In addition, we extended the model to include amygdala subregions and the mPFC to address a recent finding that the ventral mPFC (vmPFC) is required for consolidating extinction memory but not for memory retrieval. Furthermore, model simulations led us to propose a novel procedure to enhance extinction learning through re-conditioning with a stronger US; strengthened fear memory up-regulates the extinction neuron, which, in turn, further inhibits the fear neuron during re-extinction. Thus, our models increa