Encoding, retention and study.
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Qurʾān
القرآن6 shownVerses named for this subject by hand come first. The rest are found by the subject’s own Arabic and English senses and are shown as lexical matches, not as anchors anyone has confirmed.
Qur'ān 30:56Arabic sense: العلم, تعلم, علم | English sense: knowledge
وَقَالَ ٱلَّذِينَ أُوتُواْ ٱلۡعِلۡمَ وَٱلۡإِيمَٰنَ لَقَدۡ لَبِثۡتُمۡ فِي كِتَٰبِ ٱللَّهِ إِلَىٰ يَوۡمِ ٱلۡبَعۡثِۖ فَهَٰذَا يَوۡمُ ٱلۡبَعۡثِ وَلَٰكِنَّكُمۡ كُنتُمۡ لَا تَعۡلَمُونَ
but those endowed with knowledge and faith will say, ‘In accordance with God’s decree, you actually lingered till the Day of Resurrection: this is the Day of Resurrection, yet you did not know.’
Qur'ān 2:102Arabic sense: تعلم, علم | English sense: knowledge, taught
وَٱتَّبَعُواْ مَا تَتۡلُواْ ٱلشَّيَٰطِينُ عَلَىٰ مُلۡكِ سُلَيۡمَٰنَۖ وَمَا كَفَرَ سُلَيۡمَٰنُ وَلَٰكِنَّ ٱلشَّيَٰطِينَ كَفَرُواْ يُعَلِّمُونَ ٱلنَّاسَ ٱلسِّحۡرَ وَمَآ أُنزِلَ عَلَى ٱلۡمَلَكَيۡنِ بِبَابِلَ هَٰرُوتَ وَمَٰرُوتَۚ وَمَا يُعَلِّمَانِ مِنۡ أَحَدٍ حَتَّىٰ يَقُولَآ إِنَّمَا نَحۡنُ فِتۡنَةࣱ فَلَا تَكۡفُرۡۖ فَيَتَعَلَّمُونَ مِنۡهُمَا مَا يُفَرِّقُونَ بِهِۦ بَيۡنَ ٱلۡمَرۡءِ وَزَوۡجِهِۦۚ وَمَا هُم بِضَآرِّينَ بِهِۦ مِنۡ أَحَدٍ إِلَّا بِإِذۡنِ ٱللَّهِۚ وَيَتَعَلَّمُونَ مَا يَضُرُّهُمۡ وَلَا يَنفَعُهُمۡۚ وَلَقَدۡ عَلِمُواْ لَمَنِ ٱشۡتَرَىٰهُ مَا لَهُۥ فِي ٱلۡأٓخِرَةِ مِنۡ خَلَٰقࣲۚ وَلَبِئۡسَ مَا شَرَوۡاْ بِهِۦٓ أَنفُسَهُمۡۚ لَوۡ كَانُواْ يَعۡلَمُونَ
and followed what the evil ones had fabricated about the Kingdom of Solomon instead. Not that Solomon himself was a disbeliever; it was the evil ones who were disbelievers. They taught people witchcraft and what was revealed in Babylon to the two angels Harut and Marut. Yet these two never taught anyone without first warning him, ‘We are sent only to tempt- do not disbelieve.’ From these two, they learned what can cause discord between man and wife, although they harm no one with it except by God’s leave. They learned what harmed them, not what benefited them, knowing full well that whoever gained [this knowledge] would lose any share in the Hereafter. Evil indeed is the [price] for which they sold their souls, if only they knew
Qur'ān 2:282Arabic sense: علم | English sense: forget, knowledge, taught
يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓاْ إِذَا تَدَايَنتُم بِدَيۡنٍ إِلَىٰٓ أَجَلࣲ مُّسَمࣰّ ى فَٱكۡتُبُوهُۚ وَلۡيَكۡتُب بَّيۡنَكُمۡ كَاتِبُۢ بِٱلۡعَدۡلِۚ وَلَا يَأۡبَ كَاتِبٌ أَن يَكۡتُبَ كَمَا عَلَّمَهُ ٱللَّهُۚ فَلۡيَكۡتُبۡ وَلۡيُمۡلِلِ ٱلَّذِي عَلَيۡهِ ٱلۡحَقُّ وَلۡيَتَّقِ ٱللَّهَ رَبَّهُۥ وَلَا يَبۡخَسۡ مِنۡهُ شَيۡـࣰٔ اۚ فَإِن كَانَ ٱلَّذِي عَلَيۡهِ ٱلۡحَقُّ سَفِيهًا أَوۡ ضَعِيفًا أَوۡ لَا يَسۡتَطِيعُ أَن يُمِلَّ هُوَ فَلۡيُمۡلِلۡ وَلِيُّهُۥ بِٱلۡعَدۡلِۚ وَٱسۡتَشۡهِدُواْ شَهِيدَيۡنِ مِن رِّجَالِكُمۡۖ فَإِن لَّمۡ يَكُونَا رَجُلَيۡنِ فَرَجُلࣱ وَٱمۡرَأَتَانِ مِمَّن تَرۡضَوۡنَ مِنَ ٱلشُّهَدَآءِ أَن تَضِلَّ إِحۡدَىٰهُمَا فَتُذَكِّرَ إِحۡدَىٰهُمَا ٱلۡأُخۡرَىٰۚ وَلَا يَأۡبَ ٱلشُّهَدَآءُ إِذَا مَا دُعُواْۚ وَلَا تَسۡـَٔمُوٓاْ أَن تَكۡتُبُوهُ صَغِيرًا أَوۡ كَبِيرًا إِلَىٰٓ أَجَلِهِۦۚ ذَٰلِكُمۡ أَقۡسَطُ عِندَ ٱللَّهِ وَأَقۡوَمُ لِلشَّهَٰدَةِ وَأَدۡنَىٰٓ أَلَّا تَرۡتَابُوٓاْ إِلَّآ أَن تَكُونَ تِجَٰرَةً حَاضِرَةࣰ تُدِيرُونَهَا بَيۡنَكُمۡ فَلَيۡسَ عَلَيۡكُمۡ جُنَاحٌ أَلَّا تَكۡتُبُوهَاۗ وَأَشۡهِدُوٓاْ إِذَا تَبَايَعۡتُمۡۚ وَلَا يُضَآرَّ كَاتِبࣱ وَلَا شَهِيدࣱۚ وَإِن تَفۡعَلُواْ فَإِنَّهُۥ فُسُوقُۢ بِكُمۡۗ وَٱتَّقُواْ ٱللَّهَۖ وَيُعَلِّمُكُمُ ٱللَّهُۗ وَٱللَّهُ بِكُلِّ شَيۡءٍ عَلِيمࣱ
You who believe, when you contract a debt for a stated term, put it down in writing: have a scribe write it down justly between you. No scribe should refuse to write: let him write as God has taught him, let the debtor dictate, and let him fear God, his Lord, and not diminish [the debt] at all. If the debtor is feeble-minded, weak, or unable to dictate, then let his guardian dictate justly. Call in two men as witnesses. If two men are not there, then call one man and two women out of those you approve as witnesses, so that if one of the two women should forget the other can remind her. Let the witnesses not refuse when they are summoned. Do not disdain to write the debt down, be it small or large, along with the time it falls due: this way is more equitable in God’s eyes, more reliable as testimony, and more likely to prevent doubts arising between you. But if the merchandise is there and you hand it over, there is no blame on you if you do not write it down. Have witnesses present whenever you trade with one another, and let no harm be done to either scribe or witness, for if you did cause them harm, it would be a crime on your part. Be mindful of God, and He will teach you: He has full knowledge of everything
Qur'ān 2:120Arabic sense: العلم, علم | English sense: knowledge
وَلَن تَرۡضَىٰ عَنكَ ٱلۡيَهُودُ وَلَا ٱلنَّصَٰرَىٰ حَتَّىٰ تَتَّبِعَ مِلَّتَهُمۡۗ قُلۡ إِنَّ هُدَى ٱللَّهِ هُوَ ٱلۡهُدَىٰۗ وَلَئِنِ ٱتَّبَعۡتَ أَهۡوَآءَهُم بَعۡدَ ٱلَّذِي جَآءَكَ مِنَ ٱلۡعِلۡمِ مَا لَكَ مِنَ ٱللَّهِ مِن وَلِيࣲّ وَلَا نَصِيرٍ
The Jews and the Christians will never be pleased with you unless you follow their ways. Say, ‘God’s guidance is the only true guidance.’ If you were to follow their desires after the knowledge that has come to you, you would find no one to protect you from God or help you
Qur'ān 2:145Arabic sense: العلم, علم | English sense: knowledge
وَلَئِنۡ أَتَيۡتَ ٱلَّذِينَ أُوتُواْ ٱلۡكِتَٰبَ بِكُلِّ ءَايَةࣲ مَّا تَبِعُواْ قِبۡلَتَكَۚ وَمَآ أَنتَ بِتَابِعࣲ قِبۡلَتَهُمۡۚ وَمَا بَعۡضُهُم بِتَابِعࣲ قِبۡلَةَ بَعۡضࣲۚ وَلَئِنِ ٱتَّبَعۡتَ أَهۡوَآءَهُم مِّنۢ بَعۡدِ مَا جَآءَكَ مِنَ ٱلۡعِلۡمِ إِنَّكَ إِذࣰ ا لَّمِنَ ٱلظَّٰلِمِينَ
Yet even if you brought every proof to those who were given the Scripture, they would not follow your prayer direction, nor will you follow theirs, nor indeed will any of them follow one another’s direction. If you [Prophet] were to follow their desires, after the knowledge brought to you, you would be doing wrong
Qur'ān 2:247English sense: knowledge | Arabic sense: العلم, علم
وَقَالَ لَهُمۡ نَبِيُّهُمۡ إِنَّ ٱللَّهَ قَدۡ بَعَثَ لَكُمۡ طَالُوتَ مَلِكࣰ اۚ قَالُوٓاْ أَنَّىٰ يَكُونُ لَهُ ٱلۡمُلۡكُ عَلَيۡنَا وَنَحۡنُ أَحَقُّ بِٱلۡمُلۡكِ مِنۡهُ وَلَمۡ يُؤۡتَ سَعَةࣰ مِّنَ ٱلۡمَالِۚ قَالَ إِنَّ ٱللَّهَ ٱصۡطَفَىٰهُ عَلَيۡكُمۡ وَزَادَهُۥ بَسۡطَةࣰ فِي ٱلۡعِلۡمِ وَٱلۡجِسۡمِۖ وَٱللَّهُ يُؤۡتِي مُلۡكَهُۥ مَن يَشَآءُۚ وَٱللَّهُ وَٰسِعٌ عَلِيمࣱ
Their prophet said to them, ‘God has now appointed Talut to be your king,’ but they said, ‘How can he be king over us when we have a greater right to rule than he? He does not even have great wealth.’ He said, ‘God has chosen him over you, and has given him great knowledge and stature. God grants His authority to whoever He pleases: God is magnanimous, all knowing.’
Research library, full list
501 to 525 of 995Koch G, Bonnì S, Pellicciari MC, Casula EP, Mancini M, Esposito R, Ponzo V, Picazio S, Picazio S, Di Lorenzo F, Serra L, Motta C, Maiella M, Marra C, Cercignani M, Martorana A, Caltagirone C, Bozzali M (2018)MEDLINE-indexed journal, not yet read by usNeuroImage269 citations Transcranial magnetic stimulation of the precuneus enhances memory and neural activity in prodromal Alzheimer's disease.
Memory loss is one of the first symptoms of typical Alzheimer's disease (AD), for which there are no effective therapies available. The precuneus (PC) has been recently emphasized as a key area for the memory impairment observed in early AD, likely due to disconnection mechanisms within large-scale networks such as the default mode network (DMN). Using a multimodal approach we investigated in a two-week, randomized, sham-controlled, double-blinded trial the effects of high-frequency repetitive transcranial magnetic stimulation (rTMS) of the PC on cognition, as measured by the Alzheimer Disease Cooperative Study Preclinical Alzheimer Cognitive Composite in 14 patients with early AD (7 females). TMS combined with electroencephalography (TMS-EEG) was used to detect changes in brain connectivity. We found that rTMS of the PC induced a selective improvement in episodic memory, but not in othe…
matched on Memory, Episodic (mesh), Memory (keyword)
Bottary R, Seo J, Daffre C, Gazecki S, Moore KN, Kopotiyenko K, Dominguez JP, Gannon K, Lasko NB, Roth B, Milad MR, Pace-Schott EF (2020)MEDLINE-indexed journal, not yet read by usSleep41 citations Fear extinction memory is negatively associated with REM sleep in insomnia disorder.
Study objectives: Formation and maintenance of fear-extinction memories are disrupted in post-traumatic stress disorder (PTSD) and anxiety disorders. Sleep contributes to emotional memory consolidation and emotion regulation. Insomnia disorder (ID) is characterized by persistent sleep disturbance as well as rapid eye movement (REM) sleep abnormalities and often precedes or develops in parallel with PTSD and anxiety disorders. Here, we explore the impact of chronic poor sleep and sleep immediately following fear conditioning and extinction learning on preservation of extinction memories.
Methods: Twenty-four ID age- and sex-matched to 24 healthy, good sleeper controls (GS) completed up to 2 weeks of habitual sleep monitoring with daily sleep-wake diaries and actigraphy, and then participated in a two-session fear conditioning, extinction learning and extinction recall procedure. Fear Cond…
matched on Memory (mesh), memory consolidation (text)
Thalamic Spindles Promote Memory Formation during Sleep through Triple Phase-Locking of Cortical, Thalamic, and Hippocampal Rhythms.
While the interaction of the cardinal rhythms of non-rapid-eye-movement (NREM) sleep-the thalamo-cortical spindles, hippocampal ripples, and the cortical slow oscillations-is thought to be critical for memory consolidation during sleep, the role spindles play in this interaction is elusive. Combining optogenetics with a closed-loop stimulation approach in mice, we show here that only thalamic spindles induced in-phase with cortical slow oscillation up-states, but not out-of-phase-induced spindles, improve consolidation of hippocampus-dependent memory during sleep. Whereas optogenetically stimulated spindles were as efficient as spontaneous spindles in nesting hippocampal ripples within their excitable troughs, stimulation in-phase with the slow oscillation up-state increased spindle co-occurrence and frontal spindle-ripple co-occurrence, eventually resulting in increased triple coupling …
matched on Memory (mesh), memory consolidation (text)
Coordinated infraslow neural and cardiac oscillations mark fragility and offline periods in mammalian sleep.
Rodents sleep in bouts lasting minutes; humans sleep for hours. What are the universal needs served by sleep given such variability? In sleeping mice and humans, through monitoring neural and cardiac activity (combined with assessment of arousability and overnight memory consolidation, respectively), we find a previously unrecognized hallmark of sleep that balances two fundamental yet opposing needs: to maintain sensory reactivity to the environment while promoting recovery and memory consolidation. Coordinated 0.02-Hz oscillations of the sleep spindle band, hippocampal ripple activity, and heart rate sequentially divide non-rapid eye movement (non-REM) sleep into offline phases and phases of high susceptibility to external stimulation. A noise stimulus chosen such that sleeping mice woke up or slept through at comparable rates revealed that offline periods correspond to raising, whereas…
matched on Memory (mesh), memory consolidation (text)
Sleep deprivation effects on object discrimination task in zebrafish (Danio rerio).
The zebrafish is an ideal vertebrate model for neurobehavioral studies with translational relevance to humans. Many aspects of sleep have been studied, but we still do not understand how and why sleep deprivation alters behavioral and physiological processes. A number of hypotheses suggest its role in memory consolidation. In this respect, the aim of this study was to analyze the effects of sleep deprivation on memory in zebrafish (Danio rerio), using an object discrimination paradigm. Four treatments were tested: control, partial sleep deprivation, total sleep deprivation by light pulses, and total sleep deprivation by extended light. The control group explored the new object more than the known object, indicating clear discrimination. The partially sleep-deprived group explored the new object more than the other object in the discrimination phase, suggesting a certain degree of discrim…
matched on Memory (mesh), memory consolidation (text)
Selectivity in Postencoding Connectivity with High-Level Visual Cortex Is Associated with Reward-Motivated Memory.
Reward motivation has been demonstrated to enhance declarative memory by facilitating systems-level consolidation. Although high-reward information is often intermixed with lower reward information during an experience, memory for high value information is prioritized. How is this selectivity achieved? One possibility is that postencoding consolidation processes bias memory strengthening to those representations associated with higher reward. To test this hypothesis, we investigated the influence of differential reward motivation on the selectivity of postencoding markers of systems-level memory consolidation. Human participants encoded intermixed, trial-unique memoranda that were associated with either high or low-value during fMRI acquisition. Encoding was interleaved with periods of rest, allowing us to investigate experience-dependent changes in connectivity as they related to later …
matched on Memory (mesh), memory consolidation (text)
A single pair of neurons links sleep to memory consolidation in Drosophila melanogaster.
Sleep promotes memory consolidation in humans and many other species, but the physiological and anatomical relationships between sleep and memory remain unclear. Here, we show the dorsal paired medial (DPM) neurons, which are required for memory consolidation in Drosophila, are sleep-promoting inhibitory neurons. DPMs increase sleep via release of GABA onto wake-promoting mushroom body (MB) α'/β' neurons. Functional imaging demonstrates that DPM activation evokes robust increases in chloride in MB neurons, but is unable to cause detectable increases in calcium or cAMP. Downregulation of α'/β' GABAA and GABABR3 receptors results in sleep loss, suggesting these receptors are the sleep-relevant targets of DPM-mediated inhibition. Regulation of sleep by neurons necessary for consolidation suggests that these brain processes may be functionally interrelated via their shared anatomy. These fin…
matched on Memory (mesh), memory consolidation (text)
β-amyloid disrupts human NREM slow waves and related hippocampus-dependent memory consolidation.
Independent evidence associates β-amyloid pathology with both non-rapid eye movement (NREM) sleep disruption and memory impairment in older adults. However, whether the influence of β-amyloid pathology on hippocampus-dependent memory is, in part, driven by impairments of NREM slow wave activity (SWA) and associated overnight memory consolidation is unknown. Here we show that β-amyloid burden in medial prefrontal cortex (mPFC) correlates significantly with the severity of impairment in NREM SWA generation. Moreover, reduced NREM SWA generation was further associated with impaired overnight memory consolidation and impoverished hippocampal-neocortical memory transformation. Furthermore, structural equation models revealed that the association between mPFC β-amyloid pathology and impaired hippocampus-dependent memory consolidation was not direct, but instead statistically depended on the in…
matched on Memory, Episodic (mesh), memory consolidation (text)
Rescue of long-range circuit dysfunction in Alzheimer's disease models.
Alzheimer's disease (AD) is associated with defects of synaptic connectivity. Such defects may not be restricted to local neuronal interactions but may extend to long-range brain activities, such as slow-wave oscillations that are particularly prominent during non-rapid eye movement (non-REM) sleep and are important for integration of information across distant brain regions involved in memory consolidation. There is increasing evidence that sleep is often impaired in AD, but it is unclear whether this impairment is directly related to amyloid-β (Aβ) pathology. Here we demonstrate that slow-wave activity is severely altered in the neocortex, thalamus and hippocampus in mouse models of AD amyloidosis. Most notably, our results reveal an Aβ-dependent impairment of slow-wave propagation, which causes a breakdown of the characteristic long-range coherence of slow-wave activity. The finding t…
matched on Memory (mesh), memory consolidation (text)
Psychophysiological arousal at encoding leads to reduced reactivity but enhanced emotional memory following sleep.
While sleep's role in emotional memory processing is gaining increasing support, its effect on emotion regulation remains equivocal. Moreover, little is known about the link between emotional reactivity at the time of encoding and subsequent sleep-based emotional memory consolidation. This study examined whether sleep would potentiate, protect, or depotentiate measures of heart rate and skin conductance in response to scenes containing emotional and neutral objects, and assessed how these measures of reactivity would predict subsequent memory for the objects across delays of sleep and wake. Heart rate deceleration (HRD) and skin conductance response (SCR) data were collected at encoding and recognition. Although HRD and SCR reactivity to objects were depotentiated after a sleep-filled delay, they remained unchanged after a delay containing wakefulness. Moreover, increased arousal respons…
matched on Memory (mesh), memory consolidation (text)
Auditory closed-loop stimulation of the sleep slow oscillation enhances memory.
Brain rhythms regulate information processing in different states to enable learning and memory formation. The <1 Hz sleep slow oscillation hallmarks slow-wave sleep and is critical to memory consolidation. Here we show in sleeping humans that auditory stimulation in phase with the ongoing rhythmic occurrence of slow oscillation up states profoundly enhances the slow oscillation rhythm, phase-coupled spindle activity, and, consequently, the consolidation of declarative memory. Stimulation out of phase with the ongoing slow oscillation rhythm remained ineffective. Closed-loop in-phase stimulation provides a straight-forward tool to enhance sleep rhythms and their functional efficacy.
matched on Memory (mesh), memory consolidation (text)
Datta S, O'Malley MW (2013)MEDLINE-indexed journal, not yet read by usThe Journal of neuroscience : the official journal of the Society for Neuroscience85 citations Fear extinction memory consolidation requires potentiation of pontine-wave activity during REM sleep.
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. T…
matched on Memory (mesh), memory consolidation (text)
Rapid remission of conditioned fear expression with extinction training paired with vagus nerve stimulation.
Background: Fearful experiences can produce long-lasting and debilitating memories. Extinction of conditioned fear requires consolidation of new memories that compete with fearful associations. In human subjects, as well as rats, posttraining stimulation of the vagus nerve enhances memory consolidation. Subjects with posttraumatic stress disorder show impaired extinction of conditioned fear. The objective of this study was to determine whether vagus nerve stimulation (VNS) can enhance the consolidation of extinction of conditioned fear.
Methods: Male Sprague-Dawley rats were trained on an auditory fear conditioning task followed by 1 to 10 days of extinction training. Treatment with vagus nerve or sham stimulation was administered concurrently with exposure to the fear conditioned stimulus. Another group was given VNS and extinction training but the VNS was not paired with exposure to co…
matched on Memory (mesh), memory consolidation (text)
Biasing the content of hippocampal replay during sleep.
The hippocampus is essential for encoding self-experienced events into memory. During sleep, neural activity in the hippocampus related to a recent experience has been observed to spontaneously reoccur, and this 'replay' has been postulated to be important for memory consolidation. Task-related cues can enhance memory consolidation when presented during a post-training sleep session, and, if memories are consolidated by hippocampal replay, a specific enhancement for this replay should be observed. To test this, we trained rats on an auditory-spatial association task while recording from neuronal ensembles in the hippocampus. We found that, during sleep, a task-related auditory cue biased reactivation events toward replaying the spatial memory associated with that cue. These results indicate that sleep replay can be manipulated by external stimulation and provide further evidence for the …
matched on Memory (mesh), memory consolidation (text)
Hippocampal-cortical interaction during periods of subcortical silence.
Hippocampal ripples, episodic high-frequency field-potential oscillations primarily occurring during sleep and calmness, have been described in mice, rats, rabbits, monkeys and humans, and so far they have been associated with retention of previously acquired awake experience. Although hippocampal ripples have been studied in detail using neurophysiological methods, the global effects of ripples on the entire brain remain elusive, primarily owing to a lack of methodologies permitting concurrent hippocampal recordings and whole-brain activity mapping. By combining electrophysiological recordings in hippocampus with ripple-triggered functional magnetic resonance imaging, here we show that most of the cerebral cortex is selectively activated during the ripples, whereas most diencephalic, midbrain and brainstem regions are strongly and consistently inhibited. Analysis of regional temporal re…
matched on Memory (mesh), memory consolidation (text)
Reduced sleep spindles and spindle coherence in schizophrenia: mechanisms of impaired memory consolidation?
Background: Sleep spindles are thought to induce synaptic changes and thereby contribute to memory consolidation during sleep. Patients with schizophrenia show dramatic reductions of both spindles and sleep-dependent memory consolidation, which may be causally related.
Methods: To examine the relations of sleep spindle activity to sleep-dependent consolidation of motor procedural memory, 21 chronic, medicated schizophrenia outpatients and 17 healthy volunteers underwent polysomnography on two consecutive nights. On the second night, participants were trained on the finger-tapping motor sequence task (MST) at bedtime and tested the following morning. The number, density, frequency, duration, amplitude, spectral content, and coherence of stage 2 sleep spindles were compared between groups and examined in relation to overnight changes in MST performance.
Results: Patients failed to show ove…
matched on Memory (mesh), memory consolidation (text)
Inhibition recruitment in prefrontal cortex during sleep spindles and gating of hippocampal inputs.
During light slow-wave sleep, the thalamo-cortical network oscillates in waxing-and-waning patterns at about 7 to 14 Hz and lasting for 500 ms to 3 s, called spindles, with the thalamus rhythmically sending strong excitatory volleys to the cortex. Concurrently, the hippocampal activity is characterized by transient and strong excitatory events, Sharp-Waves-Ripples (SPWRs), directly affecting neocortical activity--in particular the medial prefrontal cortex (mPFC)--which receives monosynaptic fibers from the ventral hippocampus and subiculum. Both spindles and SPWRs have been shown to be strongly involved in memory consolidation. However, the dynamics of the cortical network during natural sleep spindles and how prefrontal circuits simultaneously process hippocampal and thalamo-cortical activity remain largely undetermined. Using multisite neuronal recordings in rat mPFC, we show that duri…
matched on Memory (mesh), memory consolidation (text)
Labile or stable: opposing consequences for memory when reactivated during waking and sleep.
Memory consolidation is a dynamic process. Reconsolidation theory assumes that reactivation during wakefulness transiently destabilizes memories, requiring them to reconsolidate in order to persist. Memory reactivation also occurs during slow-wave sleep (SWS) and is assumed to underlie the consolidating effect of sleep. Here, we tested whether the same principle of transient destabilization applies to memory reactivation during SWS. We reactivated memories in humans by presenting associated odor cues either during SWS or wakefulness. Reactivation was followed by an interference task to probe memory stability. As we expected, reactivation during waking destabilized memories. In contrast, reactivation during SWS immediately stabilized memories, thereby directly increasing their resistance to interference. Functional magnetic resonance imaging revealed that reactivation during SWS mainly ac…
matched on Memory (mesh), memory consolidation (text)
Fine-tuned coupling between human parahippocampal ripples and sleep spindles.
Sleep-associated memory consolidation is thought to rely on coordinated information transfer between the hippocampus and neocortex brought about during slow wave sleep (SWS) by distinct local field potential oscillations. Specifically, findings in animals have led to the concept that ripples originating from hippocampus combine with spindles to provide a fine-tuned temporal frame for a persistent transfer of memory-related information to the neocortex. The present study focused on characterizing the temporal relationship between parahippocampal ripple activity (80-140 Hz) and spindles recorded from frontal, parietal and parahippocampal cortices in 12 epilepsy patients implanted with parahippocampal foramen ovale electrodes. Overall, parietal and parahippocampal spindles showed closer relationships to parahippocampal ripple activity than frontal spindles, with the latter following parieta…
matched on Memory (mesh), memory consolidation (text)
Sleep-dependent consolidation of statistical learning.
The importance of sleep for memory consolidation has been firmly established over the past decade. Recent work has extended this by suggesting that sleep is also critical for the integration of disparate fragments of information into a unified schema, and for the abstraction of underlying rules. The question of which aspects of sleep play a significant role in integration and abstraction is, however, currently unresolved. Here, we examined the role of sleep in abstraction of the implicit probabilistic structure in sequential stimuli using a statistical learning paradigm, and tested for its role in such abstraction by searching for a predictive relationship between the type of sleep obtained and subsequent performance improvements using polysomnography. In our experiments, participants were exposed to a series of tones in a probabilistically determined sequential structure, and subsequent…
matched on Memory (mesh), memory consolidation (text)
Optogenetic disruption of sleep continuity impairs memory consolidation.
Memory consolidation has been proposed as a function of sleep. However, sleep is a complex phenomenon characterized by several features including duration, intensity, and continuity. Sleep continuity is disrupted in different neurological and psychiatric conditions, many of which are accompanied by memory deficits. This finding has raised the question of whether the continuity of sleep is important for memory consolidation. However, current techniques used in sleep research cannot manipulate a single sleep feature while maintaining the others constant. Here, we introduce the use of optogenetics to investigate the role of sleep continuity in memory consolidation. We optogenetically targeted hypocretin/orexin neurons, which play a key role in arousal processes. We used optogenetics to activate these neurons at different intervals in behaving mice and were able to fragment sleep without aff…
matched on Memory (mesh), memory consolidation (text)
Dreaming of a learning task is associated with enhanced sleep-dependent memory consolidation.
It is now well established that postlearning sleep is beneficial for human memory performance. Meanwhile, human and animal studies have demonstrated that learning-related neural activity is re-expressed during posttraining nonrapid eye movement (NREM) sleep. NREM sleep processes appear to be particularly beneficial for hippocampus-dependent forms of memory. These observations suggest that learning triggers the reactivation and reorganization of memory traces during sleep, a systems-level process that in turn enhances behavioral performance. Here, we hypothesized that dreaming about a learning experience during NREM sleep would be associated with improved performance on a hippocampus-dependent spatial memory task. Subjects were trained on a virtual navigation task and then retested on the same task 5 hr after initial training. Improved performance at retest was strongly associated with ta…
matched on Memory (mesh), memory consolidation (text)
Use-dependent plasticity in clock neurons regulates sleep need in Drosophila.
Sleep is important for memory consolidation and is responsive to waking experience. Clock circuitry is uniquely positioned to coordinate interactions between processes underlying memory and sleep need. Flies increase sleep both after exposure to an enriched social environment and after protocols that induce long-term memory. We found that flies mutant for rutabaga, period, and blistered were deficient for experience-dependent increases in sleep. Rescue of each of these genes within the ventral lateral neurons (LNVs) restores increased sleep after social enrichment. Social experiences that induce increased sleep were associated with an increase in the number of synaptic terminals in the LNV projections into the medulla. The number of synaptic terminals was reduced during sleep and this decline was prevented by sleep deprivation.
matched on Memory (mesh), memory consolidation (text)
Replay of rule-learning related neural patterns in the prefrontal cortex during sleep.
Slow-wave sleep (SWS) is important for memory consolidation. During sleep, neural patterns reflecting previously acquired information are replayed. One possible reason for this is that such replay exchanges information between hippocampus and neocortex, supporting consolidation. We recorded neuron ensembles in the rat medial prefrontal cortex (mPFC) to study memory trace reactivation during SWS following learning and execution of cross-modal strategy shifts. In general, reactivation of learning-related patterns occurred in distinct, highly synchronized transient bouts, mostly simultaneous with hippocampal sharp wave/ripple complexes (SPWRs), when hippocampal ensemble reactivation and cortico-hippocampal interaction is enhanced. During sleep following learning of a new rule, mPFC neural patterns that appeared during response selection replayed prominently, coincident with hippocampal SPWR…
matched on Memory (mesh), memory consolidation (text)
Awake replay of remote experiences in the hippocampus.
Hippocampal replay is thought to be essential for the consolidation of event memories in hippocampal-neocortical networks. Replay is present during both sleep and waking behavior, but although sleep replay involves the reactivation of stored representations in the absence of specific sensory inputs, awake replay is thought to depend on sensory input from the current environment. Here, we show that stored representations are reactivated during both waking and sleep replay. We found frequent awake replay of sequences of rat hippocampal place cells from a previous experience. This spatially remote replay was as common as local replay of the current environment and was more robust when the rat had recently been in motion than during extended periods of quiescence. Our results indicate that the hippocampus consistently replays past experiences during brief pauses in waking behavior, suggestin…
matched on Memory (mesh), memory consolidation (text)