51
|
Gottesmann C. To what extent do neurobiological sleep-waking processes support psychoanalysis? INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011; 92:233-90. [PMID: 20870071 DOI: 10.1016/s0074-7742(10)92012-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Sigmund Freud's thesis was that there is a censorship during waking that prevents memory of events, drives, wishes, and feelings from entering the consciousness because they would induce anxiety due to their emotional or ethical unacceptability. During dreaming, because the efficiency of censorship is decreased, latent thought contents can, after dream-work involving condensation and displacement, enter the dreamer's consciousness under the figurative form of manifest content. The quasi-closed dogma of psychoanalytic theory as related to unconscious processes is beginning to find neurobiological confirmation during waking. Indeed, there are active processes that suppress (repress) unwanted memories from entering consciousness. In contrast, it is more difficult to find neurobiological evidence supporting an organized dream-work that would induce meaningful symbolic content, since dream mentation most often only shows psychotic-like activities.
Collapse
Affiliation(s)
- Claude Gottesmann
- Département de Biologie, Faculté des Sciences, Université de Nice-Sophia Antipolis, Nice, France
| |
Collapse
|
52
|
Brand S, Kirov R. Sleep and its importance in adolescence and in common adolescent somatic and psychiatric conditions. Int J Gen Med 2011; 4:425-42. [PMID: 21731894 PMCID: PMC3119585 DOI: 10.2147/ijgm.s11557] [Citation(s) in RCA: 163] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Indexed: 02/05/2023] Open
Abstract
Restoring sleep is strongly associated with a better physical, cognitive, and psychological well-being. By contrast, poor or disordered sleep is related to impairment of cognitive and psychological functioning and worsened physical health. These associations are well documented not only in adults but also in children and adolescents. Importantly, adolescence is hallmarked by dramatic maturational changes in sleep and its neurobiological regulation, hormonal status, and many psychosocial and physical processes. Thus, the role of sleep in mental and physical health during adolescence and in adolescent patients is complex. However, it has so far received little attention. This review first presents contemporary views about the complex neurobiology of sleep and its functions with important implications for adolescence. Second, existing complex relationships between common adolescent somatic/organic, sleep-related, and psychiatric disorders and certain sleep alterations are discussed. It is concluded that poor or altered sleep in adolescent patients may trigger and maintain many psychiatric and physical disorders or combinations of these conditions, which presumably hinder recovery and may cross into later stages of life. Therefore, timely diagnosis and management of sleep problems appear critical for growth and development in adolescent patients.
Collapse
Affiliation(s)
- Serge Brand
- Depression and Sleep Research Unit, Psychiatric Hospital of the University of Basel, Basel, Switzerland
| | | |
Collapse
|
53
|
|
54
|
NISSEN CHRISTOPH, KLOEPFER CORINNA, FEIGE BERND, PIOSCZYK HANNAH, SPIEGELHALDER KAI, VODERHOLZER ULRICH, RIEMANN DIETER. Sleep-related memory consolidation in primary insomnia. J Sleep Res 2011; 20:129-36. [DOI: 10.1111/j.1365-2869.2010.00872.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
55
|
Marshall L, Kirov R, Brade J, Mölle M, Born J. Transcranial electrical currents to probe EEG brain rhythms and memory consolidation during sleep in humans. PLoS One 2011; 6:e16905. [PMID: 21340034 PMCID: PMC3038929 DOI: 10.1371/journal.pone.0016905] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 01/17/2011] [Indexed: 11/18/2022] Open
Abstract
Previously the application of a weak electric anodal current oscillating with a frequency of the sleep slow oscillation (∼0.75 Hz) during non-rapid eye movement sleep (NonREM) sleep boosted endogenous slow oscillation activity and enhanced sleep-associated memory consolidation. The slow oscillations occurring during NonREM sleep and theta oscillations present during REM sleep have been considered of critical relevance for memory formation. Here transcranial direct current stimulation (tDCS) oscillating at 5 Hz, i.e., within the theta frequency range (theta-tDCS) is applied during NonREM and REM sleep. Theta-tDCS during NonREM sleep produced a global decrease in slow oscillatory activity conjoint with a local reduction of frontal slow EEG spindle power (8-12 Hz) and a decrement in consolidation of declarative memory, underlining the relevance of these cortical oscillations for sleep-dependent memory consolidation. In contrast, during REM sleep theta-tDCS appears to increase global gamma (25-45 Hz) activity, indicating a clear brain state-dependency of theta-tDCS. More generally, results demonstrate the suitability of oscillating-tDCS as a tool to analyze functions of endogenous EEG rhythms and underlying endogenous electric fields as well as the interactions between EEG rhythms of different frequencies.
Collapse
Affiliation(s)
- Lisa Marshall
- Department of Neuroendocrinology, University of Lübeck, Lübeck, Germany.
| | | | | | | | | |
Collapse
|
56
|
Marrone DF, Satvat E, Shaner MJ, Worley PF, Barnes CA. Attenuated long-term Arc expression in the aged fascia dentata. Neurobiol Aging 2010; 33:979-90. [PMID: 20850902 DOI: 10.1016/j.neurobiolaging.2010.07.022] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2010] [Revised: 07/19/2010] [Accepted: 07/30/2010] [Indexed: 12/26/2022]
Abstract
One prominent component of aging is a defect in memory stabilization. To understand how the formation of enduring memories is altered in the aged brain, long-term markers of the biological events that may mediate memory consolidation were used to examine the activity dynamics of hippocampal circuits over extended intervals. The immediate early gene Arc, which is implicated in both durable memory and synaptic plasticity, is expressed in the fascia dentata (FD) for long periods following behavioral experience. To test the hypothesis that aging alters long-term Arc transcription in the FD, a region critical for spatial memory and impaired with progressive age, young and aged rats explored a novel environment twice, separated by an 8-hour interval, and FD Arc transcription was assessed. Relative to young rats, (a) fewer granule cells in the aged FD transcribe arc 8 hours after spatial exploration, and (b) this decrease is correlated with impaired spatial memory. These findings are consistent with behavioral evidence of age-related decline in hippocampal-dependent memory processing long after an event is to be remembered, and reaffirm the integral role of the FD in the neural circuits supporting durable memory.
Collapse
Affiliation(s)
- Diano F Marrone
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ 85724, USA
| | | | | | | | | |
Collapse
|
57
|
Abstract
Activity of single neurons in the motor cortex has been shown to change during acquisition of motor skills. We previously reported that the combined activity of cell ensembles in the motor cortex of monkeys (Macaca fascicularis) evolves during adaptation to a novel force field perturbation to encode the direction of compensatory force when reaching to visual targets. We also showed that the population directional signal was altered by the available sensory feedback. Here, we examined whether traces of such activity would linger on to later constitute motor memories of the newly acquired skill and whether memory traces would differ depending on feedback. We found that motor-cortical cell ensembles retained features of their adaptive activity pattern in the absence of perturbation when reaching to both learned and unlearned targets. Moreover, the preferred directions of these cells rotated in the direction of force field while the entire population of cells produced no net rotation of preferred direction when returning to null-field reaches. Whereas the activity pattern and preferred direction rotations were comparable with and without visual feedback, changes in tuning amplitudes differed across feedback conditions. Last, savings in behavioral performance and neuronal activity during later reexposure to force field were apparent. Overall, the findings reflect a novel representation of motor memory by cell ensembles and indicate a putative role of the motor cortex in early acquisition of motor memory.
Collapse
|
58
|
Abstract
Zusammenfassung. Das Mentale Training im Sinne der planmäßig wiederholten Vorstellung einer motorischen Fertigkeit ist ein zentraler Gegenstand der sportwissenschaftlichen Forschung und eine wichtige Trainingsergänzung in der Sportpraxis. Für das bessere Verständnis der Trainingswirkung wird in diesem Beitrag vorgeschlagen, Mentales Training als Simulation zu verstehen. Der Begriff der Simulation bezieht sich, erstens, auf die neuronale Ebene, also der Aktivierung von motorischen Arealen während der Bewegungsvorstellung. Zweitens, auf die motorische Kontrollebene und der Umsetzung durch interne Modelle, wobei das Vorwärtsmodell als Emulator gesehen wird. Drittens, auf die Wirkungsweise des Mentalen Trainings mit einer Fokussierung auf die Korrektur der zentralen Prozesse anhand der simulierten Rückmeldungen des Emulators. Der Ansatz der Simulation lässt sich auf andere mentale Zustände, die motorische Handlungen abbilden, übertragen und bietet somit einen generellen Erklärungsansatz für motorische Leistungsveränderungen, die durch kognitive Prozesse verursacht werden. Zudem deckt der Simulationsbegriff die flexible und phänomenale Sicht des mental Trainierenden ab. Der Ansatz der Simulation bietet auf verschiedenen Ebenen Vorhersagen, die zukünftige Untersuchungen in diesem Bereich fruchtbar anregen sollten.
Collapse
|
59
|
Return of Excitatory Waves from Field CA1 to the Hippocampal Formation Is Facilitated after Tetanization of Schäffer Collaterals during Sleep. ACTA ACUST UNITED AC 2010; 40:315-23. [DOI: 10.1007/s11055-010-9258-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Accepted: 06/09/2008] [Indexed: 11/30/2022]
|
60
|
Kopasz M, Loessl B, Hornyak M, Riemann D, Nissen C, Piosczyk H, Voderholzer U. Sleep and memory in healthy children and adolescents - a critical review. Sleep Med Rev 2010; 14:167-77. [PMID: 20093053 DOI: 10.1016/j.smrv.2009.10.006] [Citation(s) in RCA: 151] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 10/19/2009] [Accepted: 10/19/2009] [Indexed: 11/16/2022]
Abstract
There is mounting evidence that sleep is important for learning, memory and the underlying neural plasticity. This article aims to review published studies that evaluate the association between sleep, its distinct stages and memory systems in healthy children and adolescents. Furthermore it intends to suggest directions for future research. A computerised search of the literature for relevant articles published between 1966 and March 2008 was performed using the keywords "sleep", "memory", "learn", "child", "adolescents", "adolescence" and "teenager". Fifteen studies met the inclusion criteria. Published studies focused on the impact of sleep on working memory and memory consolidation. In summary, most studies support the hypothesis that sleep facilitates working memory as well as memory consolidation in children and adolescents. There is evidence that performance in abstract and complex tasks involving higher brain functions declines more strongly after sleep deprivation than the performance in simple memory tasks. Future studies are needed to better understand the impact of a variety of variables potentially modulating the interplay between sleep and memory, such as developmental stage, socioeconomic burden, circadian factors, or the level of post-learning sensory and motor activity (interference). This line of research can provide valuable input relevant to teaching, learning and public health policy.
Collapse
Affiliation(s)
- Marta Kopasz
- Department of Psychiatry and Psychotherapy, University Medical Center Freiburg, Hauptstrasse 5, 79104 Freiburg, Germany
| | | | | | | | | | | | | |
Collapse
|
61
|
Abstract
Mechanism is at the heart of understanding, and this chapter addresses underlying brain mechanisms and pathways of cognition and the impact of sleep on these processes, especially those serving learning and memory. This chapter reviews the current understanding of the relationship between sleep/waking states and cognition from the perspective afforded by basic neurophysiological investigations. The extensive overlap between sleep mechanisms and the neurophysiology of learning and memory processes provide a foundation for theories of a functional link between the sleep and learning systems. Each of the sleep states, with its attendant alterations in neurophysiology, is associated with facilitation of important functional learning and memory processes. For rapid eye movement (REM) sleep, salient features such as PGO waves, theta synchrony, increased acetylcholine, reduced levels of monoamines and, within the neuron, increased transcription of plasticity-related genes, cumulatively allow for freely occurring bidirectional plasticity, long-term potentiation (LTP) and its reversal, depotentiation. Thus, REM sleep provides a novel neural environment in which the synaptic remodelling essential to learning and cognition can occur, at least within the hippocampal complex. During non-REM sleep Stage 2 spindles, the cessation and subsequent strong bursting of noradrenergic cells and coincident reactivation of hippocampal and cortical targets would also increase synaptic plasticity, allowing targeted bidirectional plasticity in the neocortex as well. In delta non-REM sleep, orderly neuronal reactivation events in phase with slow wave delta activity, together with high protein synthesis levels, would facilitate the events that convert early LTP to long-lasting LTP. Conversely, delta sleep does not activate immediate early genes associated with de novo LTP. This non-REM sleep-unique genetic environment combined with low acetylcholine levels may serve to reduce the strength of cortical circuits that activate in the ~50% of delta-coincident reactivation events that do not appear in their waking firing sequence. The chapter reviews the results of manipulation studies, typically total sleep or REM sleep deprivation, that serve to underscore the functional significance of the phenomenological associations. Finally, the implications of sleep neurophysiology for learning and memory will be considered from a larger perspective in which the association of specific sleep states with both potentiation or depotentiation is integrated into mechanistic models of cognition.
Collapse
Affiliation(s)
- Gina R Poe
- Departments of Anesthesiology and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
| | | | | |
Collapse
|
62
|
Li X, Li D, Voss LJ, Sleigh JW. The comodulation measure of neuronal oscillations with general harmonic wavelet bicoherence and application to sleep analysis. Neuroimage 2009; 48:501-14. [PMID: 19615451 DOI: 10.1016/j.neuroimage.2009.07.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 06/19/2009] [Accepted: 07/03/2009] [Indexed: 11/15/2022] Open
Abstract
Brain functions are related to neuronal networks of different sizes and distribution, and neuronal networks of different sizes oscillate at different frequencies. Thus the synchronization of neuronal networks is often reflected by cross-frequency interaction. The description of this cross-frequency interaction is therefore a crucial issue in understanding the modulation mechanisms between neuronal populations. A number of different kinds of interaction between frequencies have been reported. In this paper, we develop a general harmonic wavelet transform based bicoherence using a phase randomization method. This allows us to measure the comodulation of oscillations between different frequency bands in neuronal populations. The performance of the method is evaluated by a simulation study. The results show that the improved wavelet bicoherence method can detect a reliable phase coupling value, and also identify zero bicoherence for waves that are not phase-coupled. Spurious bicoherences can be effectively eliminated through the phase randomization method. Finally, this method is applied to electrocorticogram data recorded from rats during transitions between slow-wave sleep, rapid-eye movement sleep and waking. The phase coupling in rapid-eye movement sleep is statistically lower than that during slow-wave sleep, and slightly less than those in the wakeful state. The degree of phase coupling in rapid-eye movement sleep after slow-wave sleep is greater than in rapid-eye movement sleep prior to waking. This method could be applied to investigate the cross-frequency interactions in other physiological signals.
Collapse
Affiliation(s)
- Xiaoli Li
- Institute of Electrical Engineering, Yanshan University, Qinhuangdao, Hebei, 066004, China.
| | | | | | | |
Collapse
|
63
|
Rasch B, Gais S, Born J. Impaired off-line consolidation of motor memories after combined blockade of cholinergic receptors during REM sleep-rich sleep. Neuropsychopharmacology 2009; 34:1843-53. [PMID: 19194375 DOI: 10.1038/npp.2009.6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rapid eye movement (REM) sleep has been considered important for the consolidation of memories, particularly of procedural skills. REM sleep, in contrast to slow-wave sleep (SWS), is hallmarked by the high, wake-like activity of the neurotransmitter acetylcholine (ACh), which promotes certain synaptic plastic processes underlying the formation of memories. Here, we show in healthy young men that off-line consolidation of a motor skill during a period of late sleep with high amounts of REM sleep depends essentially on high cholinergic activity. After a 3-h sleep period during the early night to satisfy the need for SWS, subjects learned a procedural finger sequence tapping task and a declarative word-pair learning task. After learning, they received either placebo or a combination of the muscarinic receptor antagonist scopolamine (4 microg/kg bodyweight, intravenously) and the nicotinic receptor antagonist mecamylamine (5 mg, orally), and then slept for another 3 h, ie, the late nocturnal sleep period, which is dominated by REM sleep. Retrieval was tested the following evening. Combined cholinergic receptor blockade significantly impaired motor skill consolidation, whereas word-pair memory remained unaffected. Additional data show that the impairing effect of cholinergic receptor blockade is specific to sleep-dependent consolidation of motor skill and does not occur during a wake-retention interval. Taken together, these results identify high cholinergic activity during late, REM sleep-rich sleep as an essential factor promoting sleep-dependent consolidation of motor skills.
Collapse
Affiliation(s)
- Björn Rasch
- Department of Neuroendocrinology, University of Lübeck, Lübeck, Germany
| | | | | |
Collapse
|
64
|
The hyperarousal model of insomnia: a review of the concept and its evidence. Sleep Med Rev 2009; 14:19-31. [PMID: 19481481 DOI: 10.1016/j.smrv.2009.04.002] [Citation(s) in RCA: 1056] [Impact Index Per Article: 70.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2009] [Revised: 04/06/2009] [Accepted: 04/14/2009] [Indexed: 12/11/2022]
Abstract
Primary insomnia is defined as difficulties in falling asleep, maintaining sleep or non-restorative sleep accompanied by significantly impaired daytime functioning in the absence of a specific physical, mental or substance-related cause. The current review provides substantial support for the concept that hyperarousal processes from the molecular to the higher system level play a key role in the pathophysiology of primary insomnia. Autonomous, neuroendocrine, neuroimmunological, electrophysiological and neuroimaging studies demonstrate increased levels of arousal in primary insomnia during both night and daytime. In the light of neurobiological theories of sleep-wake regulation, primary insomnia may be conceptualized as a final common pathway resulting from the interplay between a genetic vulnerability for an imbalance between arousing and sleep-inducing brain activity, psychosocial/medical stressors and perpetuating mechanisms including dysfunctional sleep-related behavior, learned sleep preventing associations and other cognitive factors like tendency to worry/ruminate.
Collapse
|
65
|
Akers KG, Frankland PW. Grading Gradients: Evaluating Evidence for Time-dependent Memory Reorganization in Experimental Animals. J Exp Neurosci 2009. [DOI: 10.4137/jen.s2391] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
In humans, hippocampal damage typically produces temporally graded retrograde amnesia, with relative sparing of remote memories compared to recent memories. This observation led to the idea that as memories age, they are reorganized in a time-dependent manner. Here, we evaluate evidence for time-dependent memory reorganization in animal models. We conclude that, although hippocampal lesions may not always produce temporal gradients under all conditions, studies using alternate experimental approaches consistently support the idea that memories reorganize over time—becoming less dependent on the hippocampus and more dependent on a cortical network. We further speculate on the processes that drive memory reorganization such as sleep, memory reactivation, synaptic plasticity, and neurogenesis.
Collapse
Affiliation(s)
- Katherine G. Akers
- Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Canada
| | - Paul W. Frankland
- Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Canada
- Department of Physiology, University of Toronto, Toronto, Canada
- Institue of Medical Science, University of Toronto, Toronto, Canada
| |
Collapse
|
66
|
Abstract
Sleep following motor skill practice has repeatedly been demonstrated to enhance motor skill learning off-line (continued overnight improvements in motor skill that are not associated with additional physical practice) for young people who are healthy. Mounting evidence suggests that older people who are healthy fail to demonstrate sleep-dependent off-line motor learning. However, little is known regarding the influence of sleep on motor skill enhancement following damage to the brain. Emerging evidence suggests that individuals with brain damage, particularly following stroke, do benefit from sleep to promote off-line motor skill learning. Because rehabilitation following stroke requires learning new, and re-learning old, motor skills, awareness that individuals with stroke benefit from a period of sleep following motor skill practice to enhance skill learning could affect physical therapist practice. The objective of this article is to present the evidence demonstrating sleep-dependent off-line motor learning in young people who are healthy and the variables that may influence this beneficial sleep-dependent skill enhancement. In young people who are healthy, these variables include the stages of memory formation, the type of memory, the type of instruction provided (implicit versus explicit learning), and the task utilized. The neural mechanisms thought to be associated with sleep-dependent off-line motor learning also are considered. Research examining whether older adults who are healthy show the same benefits of sleep as do younger adults is discussed. The data suggest that older adults who are healthy do not benefit from sleep to promote off-line skill enhancement. A possible explanation for the apparent lack of sleep-dependent off-line motor learning by older adults who are healthy is presented. Last, emerging evidence showing that individuals with chronic stroke demonstrate sleep-dependent off-line motor skill learning and some of the possible mechanisms for this effect are considered.
Collapse
|
67
|
Romcy-Pereira RN, Leite JP, Garcia-Cairasco N. Synaptic plasticity along the sleep-wake cycle: implications for epilepsy. Epilepsy Behav 2009; 14 Suppl 1:47-53. [PMID: 18926929 DOI: 10.1016/j.yebeh.2008.09.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2008] [Revised: 09/22/2008] [Accepted: 09/23/2008] [Indexed: 01/04/2023]
Abstract
Activity-dependent changes in synaptic efficacy (i.e., synaptic plasticity) can alter the way neurons communicate and process information as a result of experience. Synaptic plasticity mechanisms involve both molecular and structural modifications that affect synaptic functioning, either enhancing or depressing neuronal transmission. They include redistribution of postsynaptic receptors, activation of intracellular signaling cascades, and formation/retraction of dendritic spines, among others. During the sleep-wake cycle, as the result of particular neurochemical and neuronal firing modes, distinct oscillatory patterns organize the activity of neuronal populations, modulating synaptic plasticity. Such modulation, for example, has been shown in the visual cortex following sleep deprivation and in the ability to induce hippocampal long-term potentiation during sleep. In epilepsy, synchronized behavioral states tend to contribute to the initiation of paroxystic discharges and are considered more epileptogenic than desynchronized states. Here, we review some of the current understandings of synaptic plasticity changes in wake and sleep states and how sleep may affect epileptic seizures.
Collapse
Affiliation(s)
- Rodrigo N Romcy-Pereira
- Department of Neurology, Psychiatry and Medical Psychology, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | | |
Collapse
|
68
|
Cheng RK, Williams CL, Meck WH. Oscillatory bands, neuronal synchrony and hippocampal function: implications of the effects of prenatal choline supplementation for sleep-dependent memory consolidation. Brain Res 2008; 1237:176-94. [PMID: 18793620 DOI: 10.1016/j.brainres.2008.08.077] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Revised: 08/21/2008] [Accepted: 08/22/2008] [Indexed: 01/27/2023]
Abstract
Choline supplementation of the maternal diet has long-term facilitative effects on spatial and temporal memory processes in the offspring. To further delineate the impact of early nutritional status on brain and behavior, we examined effects of prenatal-choline availability on hippocampal oscillatory frequency bands in 12 month-old male and female rats. Adult offspring of time-pregnant dams that were given a deficient level of choline (DEF=0.0 g/kg), sufficient choline (CON=1.1 g/kg) or supplemental choline (SUP=3.5 g/kg) in their chow during embryonic days (ED) 12-17 were implanted with an electroencephalograph (EEG) electrode in the hippocampal dentate gyrus in combination with an electromyograph (EMG) electrode patch implanted in the nuchal muscle. Five consecutive 8-h recording sessions revealed differential patterns of EEG activity as a function of awake, slow-wave sleep (SWS) and rapid-eye movement (REM) sleep states and prenatal choline status. The main finding was that SUP rats displayed increased power levels of gamma (30-100 Hz) band oscillations during all phases of the sleep/wake cycle. These findings are discussed within the context of a general review of neuronal oscillations (e.g., delta, theta, and gamma bands) and synchronization across multiple brain regions in relation to sleep-dependent memory consolidation in the hippocampus.
Collapse
Affiliation(s)
- Ruey-Kuang Cheng
- Department of Psychology and Neuroscience,572 Research Drive, Duke University, Durham, NC 27708, USA
| | | | | |
Collapse
|
69
|
Cartwright R. The Contribution of the Psychology of Sleep and Dreaming to Understanding Sleep-Disordered Patients. Sleep Med Clin 2008. [DOI: 10.1016/j.jsmc.2008.01.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
70
|
Eschenko O, Ramadan W, Mölle M, Born J, Sara SJ. Sustained increase in hippocampal sharp-wave ripple activity during slow-wave sleep after learning. Learn Mem 2008; 15:222-8. [PMID: 18385477 PMCID: PMC2327264 DOI: 10.1101/lm.726008] [Citation(s) in RCA: 185] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2007] [Accepted: 01/24/2008] [Indexed: 11/24/2022]
Abstract
High-frequency oscillations, known as sharp-wave/ripple (SPW-R) complexes occurring in hippocampus during slow-wave sleep (SWS), have been proposed to promote synaptic plasticity necessary for memory consolidation. We recorded sleep for 3 h after rats were trained on an odor-reward association task. Learning resulted in an increased number SPW-Rs during the first hour of post-learning SWS. The magnitude of ripple events and their duration were also elevated for up to 2 h after the newly formed memory. Rats that did not learn the discrimination during the training session did not show any change in SPW-Rs. Successful retrieval from remote memory was likewise accompanied by an increase in SPW-R density and magnitude, relative to the previously recorded baseline, but the effects were much shorter lasting and did not include increases in ripple duration and amplitude. A short-lasting increase of ripple activity was also observed when rats were rewarded for performing a motor component of the task only. There were no increases in ripple activity after habituation to the experimental environment. These experiments show that the characteristics of hippocampal high-frequency oscillations during SWS are affected by prior behavioral experience. Associative learning induces robust and sustained (up to 2 h) changes in several SPW-R characteristics, while after retrieval from remote memory or performance of a well-trained procedural aspect of the task, only transient changes in ripple density were induced.
Collapse
Affiliation(s)
- Oxana Eschenko
- Neuromodulation, Neuroplasticity and Cognition, Centre National de la Recherche Scientifique (CNRS), UMR 7102, 75005 Paris, France
| | - Wiâm Ramadan
- Neuromodulation, Neuroplasticity and Cognition, Centre National de la Recherche Scientifique (CNRS), UMR 7102, 75005 Paris, France
| | - Matthias Mölle
- Department of Neuroendocrinology, University of Lübeck, 23538 Lübeck, Germany
| | - Jan Born
- Department of Neuroendocrinology, University of Lübeck, 23538 Lübeck, Germany
| | - Susan J. Sara
- Neuromodulation, Neuroplasticity and Cognition, Centre National de la Recherche Scientifique (CNRS), UMR 7102, 75005 Paris, France
| |
Collapse
|
71
|
Zosimovskii VA, Korshunov VA, Markevich VA. Conditions required for the appearance of double responses in hippocampal field CA1 to application of single stimuli to Shäffer collaterals in freely moving rats. ACTA ACUST UNITED AC 2008; 38:313-21. [DOI: 10.1007/s11055-008-0044-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2006] [Accepted: 11/09/2006] [Indexed: 10/22/2022]
|
72
|
Rasch B, Born J. Maintaining memories by reactivation. Curr Opin Neurobiol 2007; 17:698-703. [DOI: 10.1016/j.conb.2007.11.007] [Citation(s) in RCA: 172] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 11/19/2007] [Accepted: 11/19/2007] [Indexed: 12/13/2022]
|
73
|
Hoffman KL, Battaglia FP, Harris K, MacLean JN, Marshall L, Mehta MR. The upshot of up states in the neocortex: from slow oscillations to memory formation. J Neurosci 2007; 27:11838-41. [PMID: 17978020 PMCID: PMC6673366 DOI: 10.1523/jneurosci.3501-07.2007] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Revised: 08/30/2007] [Accepted: 09/03/2007] [Indexed: 12/30/2022] Open
Affiliation(s)
- Kari L Hoffman
- Department of Psychology, York University, Toronto, Ontario, Canada M3J 1P3.
| | | | | | | | | | | |
Collapse
|
74
|
Ribeiro S, Shi X, Engelhard M, Zhou Y, Zhang H, Gervasoni D, Lin SC, Wada K, Lemos NAM, Nicolelis MAL. Novel experience induces persistent sleep-dependent plasticity in the cortex but not in the hippocampus. Front Neurosci 2007; 1:43-55. [PMID: 18982118 PMCID: PMC2577304 DOI: 10.3389/neuro.01.1.1.003.2007] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Accepted: 09/01/2007] [Indexed: 11/13/2022] Open
Abstract
Episodic and spatial memories engage the hippocampus during acquisition but migrate to the cerebral cortex over time. We have recently proposed that the interplay between slow-wave (SWS) and rapid eye movement (REM) sleep propagates recent synaptic changes from the hippocampus to the cortex. To test this theory, we jointly assessed extracellular neuronal activity, local field potentials (LFP), and expression levels of plasticity-related immediate-early genes (IEG) arc and zif-268 in rats exposed to novel spatio-tactile experience. Post-experience firing rate increases were strongest in SWS and lasted much longer in the cortex (hours) than in the hippocampus (minutes). During REM sleep, firing rates showed strong temporal dependence across brain areas: cortical activation during experience predicted hippocampal activity in the first post-experience hour, while hippocampal activation during experience predicted cortical activity in the third post-experience hour. Four hours after experience, IEG expression was specifically upregulated during REM sleep in the cortex, but not in the hippocampus. Arc gene expression in the cortex was proportional to LFP amplitude in the spindle-range (10-14 Hz) but not to firing rates, as expected from signals more related to dendritic input than to somatic output. The results indicate that hippocampo-cortical activation during waking is followed by multiple waves of cortical plasticity as full sleep cycles recur. The absence of equivalent changes in the hippocampus may explain its mnemonic disengagement over time.
Collapse
Affiliation(s)
- Sidarta Ribeiro
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Brazil.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
75
|
Keisler A, Ashe J, Willingham DT. Time of day accounts for overnight improvement in sequence learning. Learn Mem 2007; 14:669-72. [PMID: 17911369 DOI: 10.1101/lm.751807] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The theory that certain skills improve with a night of sleep has received considerable interest in recent years. However, because sleep typically occurs at the same time of day in humans, it is difficult to separate the effects of sleep from those of time of day. By using a version of the Serial Response Time Task, we assessed the role of sleep in implicit sequence learning while controlling for possible time-of-day effects. We replicated the apparent benefit of sleep on human participants. However, our data show that sleep does not affect implicit sequence learning; rather, time of day affects the ability of participants to express what they have learned.
Collapse
Affiliation(s)
- Aysha Keisler
- Department of Psychology, University of Virginia, Charlottesville, Virginia 22904, USA.
| | | | | |
Collapse
|
76
|
Abstract
Gaze cuing, the tendency to shift attention in the direction other individuals are looking, is hypothesized to depend on a distinct neural module. One expectation of such a module is that information processing should be encapsulated within it. Here, we tested whether familiarity, a type of social knowledge, penetrates the neural circuits governing gaze cuing. Male and female subjects viewed the face of an adult male looking left or right and then pressed a keypad to indicate the location of a target appearing randomly left or right. Responses were faster for targets congruent with gaze direction. Moreover, gaze cuing was stronger in females than males. Contrary to the modularity hypothesis, familiarity enhanced gaze cuing, but only in females. Sex differences in the effects of familiarity on gaze cuing may reflect greater adaptive significance of social information for females than males.
Collapse
|
77
|
Dahan L, Astier B, Vautrelle N, Urbain N, Kocsis B, Chouvet G. Prominent burst firing of dopaminergic neurons in the ventral tegmental area during paradoxical sleep. Neuropsychopharmacology 2007; 32:1232-41. [PMID: 17151599 DOI: 10.1038/sj.npp.1301251] [Citation(s) in RCA: 178] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Dopamine is involved in motivation, memory, and reward processing. However, it is not clear whether the activity of dopamine neurons is related or not to vigilance states. Using unit recordings in unanesthetized head restrained rats we measured the firing pattern of dopamine neurons of the ventral tegmental area across the sleep-wake cycle. We found these cells were activated during paradoxical sleep (PS) via a clear switch to a prominent bursting pattern, which is known to induce large synaptic dopamine release. This activation during PS was similar to the activity measured during the consumption of palatable food. Thus, as it does during waking in response to novelty and reward, dopamine could modulate brain plasticity and thus participate in memory consolidation during PS. By challenging the traditional view that dopamine is the only aminergic group not involved in sleep physiology, this study provides an alternative perspective that may be crucial for understanding the physiological function of PS and dream mentation.
Collapse
Affiliation(s)
- Lionel Dahan
- Laboratoire de Neuropharmacologie et Neurochimie, Université Lyon 1, Lyon, France.
| | | | | | | | | | | |
Collapse
|
78
|
Miller JE, White SA. The sleeping bird gets the song. Focus on: "HVC neural sleep activity increases with development and parallels nightly changes in song behavior". J Neurophysiol 2007; 98:3-4. [PMID: 17475721 PMCID: PMC2683918 DOI: 10.1152/jn.00443.2007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
79
|
Fischer S, Wilhelm I, Born J. Developmental Differences in Sleep's Role for Implicit Off-line Learning: Comparing Children with Adults. J Cogn Neurosci 2007; 19:214-27. [PMID: 17280511 DOI: 10.1162/jocn.2007.19.2.214] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Abstract
Sleep crucially contributes to the off-line consolidation of memories. Although this view was confirmed in numerous studies in adults, it is not known whether it can be generalized to sleep during development. Here, we examined effects of sleep on implicit memory formation considered of particular relevance in children, because brain structures underlying implicit learning develop earlier in ontogeny than structures supporting explicit learning. Subjects were 7- to 11-year-old children (n = 14) and 20- to 30-year-old adults (n = 12) tested on a serial reaction time task before (learning) and after (retest) equal length retention periods of overnight sleep and daytime wakefulness. At learning, after eight training blocks, all subjects had acquired implicit knowledge of the probabilistic rules underlying the sequential stimulus materials, as indicated by a substantial difference in response time to grammatical versus nongrammatical trials in two test blocks that followed the training blocks. At learning, this response time difference was greater in children (48.49 ± 6.08 msec) than adults (28.02 ± 3.65 msec, p < .01), but did not differ between sleep and wake retention conditions in either age group. Consistent with previous studies, retesting in the adults revealed that the reaction time differences between grammatical and nongrammatical trials increased by 9.78 ± 4.82 msec after sleep, but decreased by −12.76 ± 5.49 msec after the wake retention period (p < .01). Contrary to this finding in adults, sleep in children did not lead to an increase, but to a decrease in the reaction time difference averaging −26.68 ± 12.25 msec (p < .05), whereas across the wake retention interval the reaction time difference remained nearly unchanged. The sleep-dependent deterioration in measures of implicit sequence knowledge in children was in striking contrast to the gain of such knowledge in the adults during sleep (p < .01). Our findings indicate that the functional role of sleep in implicit memory consolidation depends on age. We speculate that the overnight decrease of implicit knowledge in children reflects a preferential effect of sleep toward the enhancement of explicit aspects of task performance that interferes with implicit performance gains.
Collapse
|
80
|
Wagner U, Hallschmid M, Rasch B, Born J. Brief sleep after learning keeps emotional memories alive for years. Biol Psychiatry 2006; 60:788-90. [PMID: 16806090 DOI: 10.1016/j.biopsych.2006.03.061] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2005] [Revised: 03/13/2006] [Accepted: 03/16/2006] [Indexed: 10/24/2022]
Abstract
BACKGROUND Sleep after learning supports memory consolidation. However, long-lasting memory effects of sleep have not yet been investigated. Postlearning sleep may be particularly involved in the long-term retention of emotional memories and could thereby contribute to the development of posttraumatic stress disorder (PTSD), a disease thought to result from overconsolidation of traumatic memories. METHODS Subjects (healthy men) who had learned neutral and emotional texts immediately before sleeping or remaining awake for the subsequent 3 hours were recontacted after 4 years for long-term memory assessment (forced-choice recognition test). RESULTS Sleep following learning compared with wakefulness enhanced memory for emotional texts after 4 years (p = .001). No such enhancement was observed for neutral texts (p = .571). CONCLUSIONS Brief periods of sleep immediately following learning cause preservation of emotional memories over several years. Sleep deprivation in the immediate aftermath of traumatic events could be a promising therapeutic measure to prevent PTSD.
Collapse
Affiliation(s)
- Ullrich Wagner
- Department of Neuroendocrinology, Medical University of Lübeck, Lübeck, Germany.
| | | | | | | |
Collapse
|
81
|
Wolansky T, Clement EA, Peters SR, Palczak MA, Dickson CT. Hippocampal slow oscillation: a novel EEG state and its coordination with ongoing neocortical activity. J Neurosci 2006; 26:6213-29. [PMID: 16763029 PMCID: PMC6675178 DOI: 10.1523/jneurosci.5594-05.2006] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2005] [Revised: 04/23/2006] [Accepted: 04/29/2006] [Indexed: 12/30/2022] Open
Abstract
State-dependent EEG in the hippocampus (HPC) has traditionally been divided into two activity patterns: theta, a large-amplitude, regular oscillation with a bandwidth of 3-12 Hz, and large-amplitude irregular activity (LIA), a less regular signal with broadband characteristics. Both of these activity patterns have been linked to the memory functions subserved by the HPC. Here we describe, using extracellular field recording techniques in naturally sleeping and urethane-anesthetized rats, a novel state present during deactivated stages of sleep and anesthesia that is characterized by a prominent large-amplitude and slow frequency (< or =1 Hz) rhythm. We have called this activity the hippocampal slow oscillation (SO) because of its similarity and correspondence with the previously described neocortical SO. Almost all hippocampal units recorded exhibited differential spiking behavior during the SO as compared with other states. Although the hippocampal SO occurred in situations similar to the neocortical SO, it demonstrated some independence in its initiation, coordination, and coherence. The SO was abolished by sensory stimulation or cholinergic agonism and was enhanced by increasing anesthetic depth or muscarinic receptor antagonism. Laminar profile analyses of the SO showed a phase shift and prominent current sink-source alternations in stratum lacunosum-moleculare of CA1. This, along with correlated slow oscillatory field and multiunit activity in superficial entorhinal cortex suggests that the hippocampal SO may be coordinated with slow neocortical activity through input arriving via the temporo-ammonic pathway. This novel state may present a favorable milieu for synchronization-dependent synaptic plasticity within and between hippocampal and neocortical ensembles.
Collapse
|
82
|
Holmes GL, Lenck-Santini PP. Role of interictal epileptiform abnormalities in cognitive impairment. Epilepsy Behav 2006; 8:504-15. [PMID: 16540376 DOI: 10.1016/j.yebeh.2005.11.014] [Citation(s) in RCA: 238] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2005] [Revised: 11/17/2005] [Accepted: 11/25/2005] [Indexed: 10/24/2022]
Abstract
The epileptic encephalopathies are conditions in which neurological deterioration is attributable entirely or partly to epileptic activity and is due to very frequent or severe seizures or severely abnormal electroencephalograms (EEGs), or both. Evidence for the concept that seizures or the abnormal EEGs are responsible for the cognitive deterioration is the observation that patients can improve dramatically when therapy eliminates or reduces seizure frequency and improves or normalizes the EEG. For example, children with the syndrome of continuous spike-wave of sleep (CSWS) have electrical status epilepticus during sleep (ESES) and cognitive regression. Although seizures often occur in the disorder, there are indications that the EEG abnormalities are responsible for the cognitive regression. Interictal spikes, which correspond to a large intracellular depolarization with evoked action potentials, in many ways mimic a "miniseizure." Interictal spikes can result in transitory cognitive impairment with the type of deficit dependent on where in the cortex the spike arises. We suggest that interictal spikes, particularly if frequent and widespread, can impair cognitive abilities, through interference with waking learning and memory, and memory consolidation during sleep.
Collapse
Affiliation(s)
- Gregory L Holmes
- Neuroscience Center at Dartmouth, Section of Neurology, Dartmouth Medical School, Hanover, NH, USA.
| | | |
Collapse
|
83
|
Booth V, Poe GR. Input source and strength influences overall firing phase of model hippocampal CA1 pyramidal cells during theta: relevance to REM sleep reactivation and memory consolidation. Hippocampus 2006; 16:161-73. [PMID: 16411243 PMCID: PMC1401491 DOI: 10.1002/hipo.20143] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In simulation studies using a realistic model CA1 pyramidal cell, we accounted for the shift in mean firing phase from theta cycle peaks to theta cycle troughs during rapid-eye movement (REM) sleep reactivation of hippocampal CA1 place cells over several days of growing familiarization with an environment (Brain Res 855:176-180). Changes in the theta drive phase and amplitude between proximal and distal dendritic regions of the cell modulated the theta phase of firing when stimuli were presented at proximal and distal dendritic locations. Stimuli at proximal dendritic sites (proximal to 100 microm from the soma) invoked firing with a significant phase preference at the depolarizing theta peaks, while distal stimuli (>290 microm from the soma) invoked firing at hyperpolarizing theta troughs. The input location-related phase preference depended on active dendritic conductances, a sufficient electrotonic separation between input sites and theta-induced subthreshold membrane potential oscillations in the cell. The simulation results predict that the shift in mean theta phase during REM sleep cellular reactivation could occur through potentiation of distal dendritic (temporo-ammonic) synapses and depotentiation of proximal dendritic (Schaffer collateral) synapses over the course of familiarization.
Collapse
Affiliation(s)
- Victoria Booth
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109-9332, USA.
| | | |
Collapse
|
84
|
Norman KA, Newman EL, Perotte AJ. Methods for reducing interference in the Complementary Learning Systems model: oscillating inhibition and autonomous memory rehearsal. Neural Netw 2005; 18:1212-28. [PMID: 16260116 DOI: 10.1016/j.neunet.2005.08.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The stability-plasticity problem (i.e. how the brain incorporates new information into its model of the world, while at the same time preserving existing knowledge) has been at the forefront of computational memory research for several decades. In this paper, we critically evaluate how well the Complementary Learning Systems theory of hippocampo-cortical interactions addresses the stability-plasticity problem. We identify two major challenges for the model: Finding a learning algorithm for cortex and hippocampus that enacts selective strengthening of weak memories, and selective punishment of competing memories; and preventing catastrophic forgetting in the case of non-stationary environments (i.e. when items are temporarily removed from the training set). We then discuss potential solutions to these problems: First, we describe a recently developed learning algorithm that leverages neural oscillations to find weak parts of memories (so they can be strengthened) and strong competitors (so they can be punished), and we show how this algorithm outperforms other learning algorithms (CPCA Hebbian learning and Leabra at memorizing overlapping patterns. Second, we describe how autonomous re-activation of memories (separately in cortex and hippocampus) during REM sleep, coupled with the oscillating learning algorithm, can reduce the rate of forgetting of input patterns that are no longer present in the environment. We then present a simple demonstration of how this process can prevent catastrophic interference in an AB-AC learning paradigm.
Collapse
Affiliation(s)
- Kenneth A Norman
- Department of Psychology Princeton University, Green Hall, Princeton, NJ 08544, USA.
| | | | | |
Collapse
|
85
|
Svarnik OE, Alexandrov YI, Gavrilov VV, Grinchenko YV, Anokhin KV. Fos expression and task-related neuronal activity in rat cerebral cortex after instrumental learning. Neuroscience 2005; 136:33-42. [PMID: 16182454 DOI: 10.1016/j.neuroscience.2005.07.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2005] [Revised: 07/18/2005] [Accepted: 07/20/2005] [Indexed: 11/27/2022]
Abstract
Learning has been shown to induce changes in neuronal gene expression and to produce development of task-specific neuronal activity. The connection between these two features of neuronal plasticity remains of a great interest. To address this issue we compared distribution of c-Fos expressing and task-related neurons in the rat cerebral cortex following instrumental learning of appetitive lever-press task. The number of Fos-positive neurons was determined immunohistochemically in the retrosplenial and the motor cortex of naive ("control" group), newly trained ("acquisition" group) and overtrained ("performance" group) animals. A significant activation of c-Fos expression was observed in the neurons of the retrosplenial but not motor cortex in the "acquisition" group rats, as compared with the "control" and "performance" groups. In accordance with this c-Fos expression difference, the retrosplenial cortex of the trained animals contained significantly more neurons with lever-press-related activity than the motor cortex. Therefore, the two examined cortical areas showed a parallel between experience-dependent induction of c-Fos and development of task-related neuronal activity. These data support a notion that learning-induced activation of c-Fos is associated with long-term neurophysiological changes produced by training.
Collapse
Affiliation(s)
- O E Svarnik
- V. B. Shvyrkov Laboratory of Neuronal Bases of Mind, Institute of Psychology, Russian Academy of Sciences, Yaroslavskaya St., 13, 129366 Moscow, Russia.
| | | | | | | | | |
Collapse
|
86
|
|
87
|
Abstract
Do our memories remain static during sleep, or do they change? We argue here that memory change is not only a natural result of sleep cognition, but further, that such change constitutes a fundamental characteristic of declarative memories. In general, declarative memories change due to retrieval events at various times after initial learning and due to the formation and elaboration of associations with other memories, including memories formed after the initial learning episode. We propose that declarative memories change both during waking and during sleep, and that such change contributes to enhancing binding of the distinct representational components of some memories, and thus to a gradual process of cross-cortical consolidation. As a result of this special form of consolidation, declarative memories can become more cohesive and also more thoroughly integrated with other stored information. Further benefits of this memory reprocessing can include developing complex networks of interrelated memories, aligning memories with long-term strategies and goals, and generating insights based on novel combinations of memory fragments. A variety of research findings are consistent with the hypothesis that cross-cortical consolidation can progress during sleep, although further support is needed, and we suggest some potentially fruitful research directions. Determining how processing during sleep can facilitate memory storage will be an exciting focus of research in the coming years.
Collapse
Affiliation(s)
- Ken A Paller
- Institute for Neuroscience and Department of Psychology, Northwestern University, Evanston, Illinois 60208-2710, USA.
| | | |
Collapse
|