351
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Jeon SJ, Park HJ, Gao Q, Pena IJD, Park SJ, Lee HE, Woo H, Kim HJ, Cheong JH, Hong E, Ryu JH. Ursolic acid enhances pentobarbital-induced sleeping behaviors via GABAergic neurotransmission in mice. Eur J Pharmacol 2015; 762:443-8. [PMID: 26102564 DOI: 10.1016/j.ejphar.2015.06.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 06/17/2015] [Accepted: 06/17/2015] [Indexed: 10/23/2022]
Abstract
Prunella vulgaris is widely used as a herbal medicine for cancers, inflammatory diseases, and other infections. Although it has long been used, few studies have examined its effects on central nervous system function. Here, we first observed that ethanolic extracts of P. vulgaris (EEPV) prolonged pentobarbital-induced sleep duration in mice. It is known that EEPV consists of many active components including triterpenoid (ursolic acid and oleanolic acid), which have many biological activities. Therefore, we evaluated which EEPV components induced sleep extension in pentobarbital-mediated sleeping model in mice. Surprisingly, despite their structural similarity and other common functions such as anti-inflammation, anti-cancer, and tissue protection, only ursolic acid enhanced sleep duration in pentobarbital-treated mice. These results were attenuated by bicuculline treatment, which is a GABAA receptor antagonist. The present results suggest that ursolic acid from P. vulgaris enhances sleep duration through GABAA receptor activation and could be a therapeutic candidate for insomnia treatment.
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Affiliation(s)
- Se Jin Jeon
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Ho Jae Park
- Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Qingtao Gao
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Irene Joy Dela Pena
- Department of Pharmacy, Sahmyook University, Seoul 139-742, Republic of Korea
| | - Se Jin Park
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Hyung Eun Lee
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Hyun Woo
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea
| | - Hee Jin Kim
- Department of Pharmacy, Sahmyook University, Seoul 139-742, Republic of Korea
| | - Jae Hoon Cheong
- Department of Pharmacy, Sahmyook University, Seoul 139-742, Republic of Korea
| | - Eunyoung Hong
- Natraceutical & Functional Foods Center, CJ Foods R&D, Seoul 152-051, Republic of Korea
| | - Jong Hoon Ryu
- Department of Life and Nanopharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Department of Oriental Pharmaceutical Science, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea; Kyung Hee East-West Pharmaceutical Research Institute, College of Pharmacy, Kyung Hee University, Kyunghee-daero 26, Dongdaemoon-Ku, Seoul 130-701, Republic of Korea.
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352
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Bassetti CL, Ferini-Strambi L, Brown S, Adamantidis A, Benedetti F, Bruni O, Cajochen C, Dolenc-Groselj L, Ferri R, Gais S, Huber R, Khatami R, Lammers GJ, Luppi PH, Manconi M, Nissen C, Nobili L, Peigneux P, Pollmächer T, Randerath W, Riemann D, Santamaria J, Schindler K, Tafti M, Van Someren E, Wetter TC. Neurology and psychiatry: waking up to opportunities of sleep. : State of the art and clinical/research priorities for the next decade. Eur J Neurol 2015; 22:1337-54. [DOI: 10.1111/ene.12781] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 06/05/2015] [Indexed: 12/22/2022]
Affiliation(s)
- C. L. Bassetti
- Department of Neurology; Inselspital, Bern University Hospital; University of Bern; Bern Switzerland
| | - L. Ferini-Strambi
- Division of Neuroscience; Sleep Disorders Centre; Università Vita-Salute San Raffaele; Milan Italy
| | - S. Brown
- Institute of Pharmacology and Toxicology; University of Zürich; Zürich Switzerland
| | - A. Adamantidis
- Department of Neurology; Inselspital, Bern University Hospital; University of Bern; Bern Switzerland
| | - F. Benedetti
- Department of Clinical Neurosciences; Scientific Institute and University Vita-Salute San Raffaele; Milan Italy
| | - O. Bruni
- Department of Developmental and Social Psychology; Sapienza University; Rome Italy
| | - C. Cajochen
- Psychiatric University Clinic; Basel Switzerland
| | - L. Dolenc-Groselj
- Division of Neurology; Institute of Clinical Neurophysiology; University Medical Centre Ljubljana; Ljubljana Slovenia
| | - R. Ferri
- Department of Neurology; Oasi Institute for Research on Mental Retardation and Brain Aging (IRCCS); Troina Italy
| | - S. Gais
- Medical Psychology and Behavioural Neurobiology; Eberhard Karls Universität Tübingen; Tübingen Germany
| | - R. Huber
- Department of Paediatrics; Children's University Hospital; Zurich Switzerland
| | - R. Khatami
- Sleep Centre; Klinik Barmelweid AG; Barmelweid Switzerland
| | - G. J. Lammers
- Department of Neurology and Clinical Neurophysiology; Leiden University Medical Centre; Leiden The Netherlands
- Sleep Wake Centre SEIN; Stichting Epilepsie Instellingen Nederland; Heemstede The Netherlands
| | - P. H. Luppi
- UMR 5292 CNRS/U1028 INSERM; Centre de Recherche en Neurosciences de Lyon (CRNL); Team “Physiopathologie des réseaux neuronaux responsables du cycle veille-sommeil”; Université Claude Bernard Lyon I; Lyon France
| | - M. Manconi
- Sleep and Epilepsy Centre; Neurocentre of Southern Switzerland; Civic Hospital (EOC) of Lugano; Lugano Switzerland
| | - C. Nissen
- Department of Clinical Psychology and Psychophysiology/Sleep Medicine; Centre for Mental Disorders; Freiburg University Medical Centre; Freiburg Germany
| | - L. Nobili
- Centre of Epilepsy Surgery ‘C. Munari’; Niguarda Hospital; Milan Italy
| | - P. Peigneux
- UR2NF - Neuropsychology and Functional Neuroimaging Research Unit; CRCN - Centre de Recherches Cognition et Neurosciences and UNI - ULB Neurosciences Institute; Université Libre de Bruxelles (ULB); Brussels Belgium
| | - T. Pollmächer
- Center of Mental Health; Klinikum Ingolstadt; Ingolstadt Germany
| | - W. Randerath
- Institut für Pneumologie; Krankenhaus Bethanien gGmbH; Universität Witten/Herdecke; Solingen Germany
| | - D. Riemann
- Department of Clinical Psychology and Psychophysiology/Sleep Medicine; Centre for Mental Disorders; Freiburg University Medical Centre; Freiburg Germany
| | - J. Santamaria
- Neurology Service; Hospital Clínic of Barcelona; Institut d'Investigació Biomèdiques August Pi i Sunyer (IDIBAPS); Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED); Barcelona Spain
| | - K. Schindler
- Department of Neurology; Inselspital, Bern University Hospital; University of Bern; Bern Switzerland
| | - M. Tafti
- Centre for Integrative Genomics; University of Lausanne; Lausanne Switzerland
- Centre for Investigation and Research in Sleep; Vaud University Hospital; Lausanne Switzerland
| | - E. Van Someren
- Department of Sleep and Cognition; Netherlands Institute for Neuroscience; Amsterdam The Netherlands
- Departments of Integrative Neurophysiology and Medical Psychology; Center for Neurogenomics and Cognitive Research (CNCR); VU University and Medical Center; Amsterdam The Netherlands
| | - T. C. Wetter
- Department of Psychiatry and Psychotherapy; University of Regensburg; Regensburg Germany
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353
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Abstract
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.
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Affiliation(s)
- Larry R Squire
- VA San Diego Healthcare System, San Diego, California 92161 Departments of Psychiatry and Neurosciences, University of California, San Diego, La Jolla, California 92093 Department of Psychology, University of California, San Diego, La Jolla, California 92093
| | - Lisa Genzel
- Centre for Cognitive and Neural Systems, The University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom
| | - John T Wixted
- Department of Psychology, University of California, San Diego, La Jolla, California 92093
| | - Richard G Morris
- Centre for Cognitive and Neural Systems, The University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom
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354
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Layer 4 pyramidal neurons exhibit robust dendritic spine plasticity in vivo after input deprivation. J Neurosci 2015; 35:7287-94. [PMID: 25948276 DOI: 10.1523/jneurosci.5215-14.2015] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Pyramidal neurons in layers 2/3 and 5 of primary somatosensory cortex (S1) exhibit somewhat modest synaptic plasticity after whisker input deprivation. Whether neurons involved at earlier steps of sensory processing show more or less plasticity has not yet been examined. Here, we used longitudinal in vivo two-photon microscopy to investigate dendritic spine dynamics in apical tufts of GFP-expressing layer 4 (L4) pyramidal neurons of the vibrissal (barrel) S1 after unilateral whisker trimming. First, we characterize the molecular, anatomical, and electrophysiological properties of identified L4 neurons in Ebf2-Cre transgenic mice. Next, we show that input deprivation results in a substantial (∼50%) increase in the rate of dendritic spine loss, acutely (4-8 d) after whisker trimming. This robust synaptic plasticity in L4 suggests that primary thalamic recipient pyramidal neurons in S1 may be particularly sensitive to changes in sensory experience. Ebf2-Cre mice thus provide a useful tool for future assessment of initial steps of sensory processing in S1.
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355
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Abstract
The <1 Hz EEG slow oscillation (SO) is a hallmark of slow-wave sleep (SWS) and is critically involved in sleep-associated memory formation. Previous studies showed that SOs and associated memory function can be effectively enhanced by closed-loop auditory stimulation, when clicks are presented in synchrony with upcoming SO up states. However, increasing SOs and synchronized excitability also bear the risk of emerging seizure activity, suggesting the presence of mechanisms in the healthy brain that counter developing hypersynchronicity during SOs. Here, we aimed to test the limits of driving SOs through closed-loop auditory stimulation in healthy humans. Study I tested a "Driving stimulation" protocol (vs "Sham") in which trains of clicks were presented in synchrony with SO up states basically as long as an ongoing SO train was identified on-line. Study II compared Driving stimulation with a "2-Click" protocol where the maximum of stimuli delivered in a train was limited to two clicks. Stimulation was applied during SWS in the first 210 min of nocturnal sleep. Before and after sleep declarative word-pair memories were tested. Compared with the Sham control, Driving stimulation prolonged SO trains and enhanced SO amplitudes, phase-locked spindle activity, and overnight retention of word pairs (all ps < 0.05). Importantly, effects of Driving stimulation did not exceed those of 2-Click stimulation (p > 0.180), indicating the presence of a mechanism preventing the development of hypersynchronicity during SO activity. Assessment of temporal dynamics revealed a rapidly fading phase-locked spindle activity during repetitive click stimulation, suggesting that spindle refractoriness contributes to this protective mechanism.
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356
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Becoming a mother-circuit plasticity underlying maternal behavior. Curr Opin Neurobiol 2015; 35:49-56. [PMID: 26143475 DOI: 10.1016/j.conb.2015.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 06/15/2015] [Indexed: 11/20/2022]
Abstract
The transition to motherhood is a dramatic event during the lifetime of many animals. In mammals, motherhood is accompanied by hormonal changes in the brain that start during pregnancy, followed by experience dependent plasticity after parturition. Together, these changes prime the nervous system of the mother for efficient nurturing of her offspring. Recent work has described how neural circuits are modified during the transition to motherhood. Here we discuss changes in the auditory cortex during motherhood as a model for maternal plasticity in sensory systems. We compare classical plasticity paradigms with changes that arise naturally in mothers, highlighting current efforts to establish a mechanistic understanding of plasticity and its different components in the context of maternal behavior.
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357
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Dumoulin Bridi MC, Aton SJ, Seibt J, Renouard L, Coleman T, Frank MG. Rapid eye movement sleep promotes cortical plasticity in the developing brain. SCIENCE ADVANCES 2015; 1:e1500105. [PMID: 26601213 PMCID: PMC4646776 DOI: 10.1126/sciadv.1500105] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 04/28/2015] [Indexed: 05/24/2023]
Abstract
Rapid eye movement sleep is maximal during early life, but its function in the developing brain is unknown. We investigated the role of rapid eye movement sleep in a canonical model of developmental plasticity in vivo (ocular dominance plasticity in the cat) induced by monocular deprivation. Preventing rapid eye movement sleep after monocular deprivation reduced ocular dominance plasticity and inhibited activation of a kinase critical for this plasticity (extracellular signal-regulated kinase). Chronic single-neuron recording in freely behaving cats further revealed that cortical activity during rapid eye movement sleep resembled activity present during monocular deprivation. This corresponded to times of maximal extracellular signal-regulated kinase activation. These findings indicate that rapid eye movement sleep promotes molecular and network adaptations that consolidate waking experience in the developing brain.
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Affiliation(s)
- Michelle C. Dumoulin Bridi
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Sara J. Aton
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- University of Michigan, Ann Arbor, MI 48109, USA
| | - Julie Seibt
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Charité–Universitätsmedizin, Berlin 10117, Germany
| | - Leslie Renouard
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- College of Medical Sciences, Washington State University, Spokane, WA 99201, USA
| | - Tammi Coleman
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marcos G. Frank
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- College of Medical Sciences, Washington State University, Spokane, WA 99201, USA
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358
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Zeek ML, Savoie MJ, Song M, Kennemur LM, Qian J, Jungnickel PW, Westrick SC. Sleep Duration and Academic Performance Among Student Pharmacists. AMERICAN JOURNAL OF PHARMACEUTICAL EDUCATION 2015; 79:63. [PMID: 26396272 PMCID: PMC4571043 DOI: 10.5688/ajpe79563] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 12/08/2014] [Indexed: 05/11/2023]
Abstract
OBJECTIVE To identify sleep patterns and frequency of daytime sleepiness and to assess the association between sleep duration and academic performance among student pharmacists. METHODS A cross-sectional design was used. An anonymous self-administered paper questionnaire was administered to first-year through third-year students at a pharmacy school. RESULTS Questionnaires were completed by 364 student pharmacists (79.4% response rate and 93.8% cooperation rate). More than half of student pharmacists obtained less than 7 hours of sleep at night during a typical school week (54.7%) and a large majority on the night prior to an examination (81.7%). Almost half (47.8%) felt daytime sleepiness almost every day. Longer sleep duration the night prior to an examination was associated with higher course grades and semester grade point averages (GPAs). CONCLUSION A majority of student pharmacists had suboptimal durations of sleep, defined as fewer than 7 hours. Adequate sleep the night prior to an examination was positively associated with student course grades and semester GPAs.
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Affiliation(s)
- Megan L Zeek
- Auburn University Harrison School of Pharmacy, Auburn, Alabama
| | | | - Matthew Song
- Auburn University Harrison School of Pharmacy, Auburn, Alabama
| | | | - Jingjing Qian
- Auburn University Harrison School of Pharmacy, Auburn, Alabama
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359
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Repeated exposure to ketamine-xylazine during early development impairs motor learning-dependent dendritic spine plasticity in adulthood. Anesthesiology 2015; 122:821-31. [PMID: 25575163 DOI: 10.1097/aln.0000000000000579] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recent studies in rodents suggest that repeated and prolonged anesthetic exposure at early stages of development leads to cognitive and behavioral impairments later in life. However, the underlying mechanism remains unknown. In this study, we tested whether exposure to general anesthesia during early development will disrupt the maturation of synaptic circuits and compromise learning-related synaptic plasticity later in life. METHODS Mice received ketamine-xylazine (20/3 mg/kg) anesthesia for one or three times, starting at either early (postnatal day 14 [P14]) or late (P21) stages of development (n = 105). Control mice received saline injections (n = 34). At P30, mice were subjected to rotarod motor training and fear conditioning. Motor learning-induced synaptic remodeling was examined in vivo by repeatedly imaging fluorescently labeled postsynaptic dendritic spines in the primary motor cortex before and after training using two-photon microscopy. RESULTS Three exposures to ketamine-xylazine anesthesia between P14 and P18 impair the animals' motor learning and learning-dependent dendritic spine plasticity (new spine formation, 8.4 ± 1.3% [mean ± SD] vs. 13.4 ± 1.8%, P = 0.002) without affecting fear memory and cell apoptosis. One exposure at P14 or three exposures between P21 and P25 has no effects on the animals' motor learning or spine plasticity. Finally, enriched motor experience ameliorates anesthesia-induced motor learning impairment and synaptic deficits. CONCLUSIONS Our study demonstrates that repeated exposures to ketamine-xylazine during early development impair motor learning and learning-dependent dendritic spine plasticity later in life. The reduction in synaptic structural plasticity may underlie anesthesia-induced behavioral impairment.
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360
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Attardo A, Fitzgerald JE, Schnitzer MJ. Impermanence of dendritic spines in live adult CA1 hippocampus. Nature 2015; 523:592-6. [PMID: 26098371 PMCID: PMC4648621 DOI: 10.1038/nature14467] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 04/10/2015] [Indexed: 01/26/2023]
Abstract
The mammalian hippocampus is crucial for episodic memory formation and transiently retains information for about 3-4 weeks in adult mice and longer in humans. Although neuroscientists widely believe that neural synapses are elemental sites of information storage, there has been no direct evidence that hippocampal synapses persist for time intervals commensurate with the duration of hippocampal-dependent memory. Here we tested the prediction that the lifetimes of hippocampal synapses match the longevity of hippocampal memory. By using time-lapse two-photon microendoscopy in the CA1 hippocampal area of live mice, we monitored the turnover dynamics of the pyramidal neurons' basal dendritic spines, postsynaptic structures whose turnover dynamics are thought to reflect those of excitatory synaptic connections. Strikingly, CA1 spine turnover dynamics differed sharply from those seen previously in the neocortex. Mathematical modelling revealed that the data best matched kinetic models with a single population of spines with a mean lifetime of approximately 1-2 weeks. This implies ∼100% turnover in ∼2-3 times this interval, a near full erasure of the synaptic connectivity pattern. Although N-methyl-d-aspartate (NMDA) receptor blockade stabilizes spines in the neocortex, in CA1 it transiently increased the rate of spine loss and thus lowered spine density. These results reveal that adult neocortical and hippocampal pyramidal neurons have divergent patterns of spine regulation and quantitatively support the idea that the transience of hippocampal-dependent memory directly reflects the turnover dynamics of hippocampal synapses.
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Affiliation(s)
- Alessio Attardo
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA [2] Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA
| | - James E Fitzgerald
- James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA
| | - Mark J Schnitzer
- 1] James H. Clark Center for Biomedical Engineering &Sciences, Stanford University, Stanford, California 94305, USA [2] Howard Hughes Medical Institute, Stanford University, Stanford, California 94305, USA [3] CNC Program, Stanford University, Stanford, California 94305, USA
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361
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Subtype-specific plasticity of inhibitory circuits in motor cortex during motor learning. Nat Neurosci 2015; 18:1109-15. [PMID: 26098758 PMCID: PMC4519436 DOI: 10.1038/nn.4049] [Citation(s) in RCA: 204] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 05/28/2015] [Indexed: 02/06/2023]
Abstract
Motor skill learning induces long-lasting reorganization of dendritic spines, principal sites of excitatory synapses, in the motor cortex. However, mechanisms that regulate these excitatory synaptic changes remain poorly understood. Here, using in vivo two-photon imaging in awake mice, we found that learning-induced spine reorganization of layer (L) 2/3 excitatory neurons occurs in the distal branches of their apical dendrites in L1 but not in the perisomatic dendrites. This compartment-specific spine reorganization coincided with subtype-specific plasticity of local inhibitory circuits. Somatostatin-expressing inhibitory neurons (SOM-INs), which mainly inhibit distal dendrites of excitatory neurons, showed a decrease in axonal boutons immediately after the training began, whereas parvalbumin-expressing inhibitory neurons (PV-INs), which mainly inhibit perisomatic regions of excitatory neurons, exhibited a gradual increase in axonal boutons during training. Optogenetic enhancement and suppression of SOM-IN activity during training destabilized and hyperstabilized spines, respectively, and both manipulations impaired the learning of stereotyped movements. Our results identify SOM inhibition of distal dendrites as a key regulator of learning-related changes in excitatory synapses and the acquisition of motor skills.
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362
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Qiao Q, Ma L, Li W, Tsai JW, Yang G, Gan WB. Long-term stability of axonal boutons in the mouse barrel cortex. Dev Neurobiol 2015; 76:252-61. [PMID: 26058471 DOI: 10.1002/dneu.22311] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 05/28/2015] [Accepted: 05/28/2015] [Indexed: 11/08/2022]
Abstract
Many lines of evidence indicate that postsynaptic dendritic spines are plastic during development and largely stable in adulthood. It remains unclear to what degree presynaptic axonal terminals undergo changes in the developing and mature cortex. In this study, we examined the formation and elimination of fluorescently-labeled axonal boutons in the living mouse barrel cortex with transcranial two-photon microscopy. We found that the turnover of axonal boutons was significantly higher in 3-week-old young mice than in adult mice (older than 3 months). There was a slight but significant net loss of axonal boutons in mice from 1 to 2 months of age. In both young and adult barrel cortex, axonal boutons existed for at least 1 week were less likely to be eliminated than those recently-formed boutons. In adulthood, 80% of axonal boutons persisted over 12 months and enriched sensory experience caused a slight but not significant increase in the turnover of axonal boutons over 2-4 weeks. Thus, similar to postsynaptic dendritic spines, presynaptic axonal boutons show remarkable stability after development ends. This long-term stability of synaptic connections is likely important for reliable sensory processing in the mature somatosensory cortex.
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Affiliation(s)
- Qian Qiao
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Lei Ma
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Wei Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Jin-Wu Tsai
- Department of Neuroscience and Physiology, Skirball Institute, New York University School of Medicine, New York, New York, 10016
| | - Guang Yang
- Department of Anesthesiology, New York University School of Medicine, New York, New York, 10016
| | - Wen-Biao Gan
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.,Department of Neuroscience and Physiology, Skirball Institute, New York University School of Medicine, New York, New York, 10016
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363
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Ma L, Qiao Q, Tsai JW, Yang G, Li W, Gan WB. Experience-dependent plasticity of dendritic spines of layer 2/3 pyramidal neurons in the mouse cortex. Dev Neurobiol 2015; 76:277-286. [PMID: 26033635 DOI: 10.1002/dneu.22313] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 05/29/2015] [Accepted: 05/29/2015] [Indexed: 11/11/2022]
Abstract
Previous studies have shown that sensory and motor experiences play an important role in the remodeling of dendritic spines of layer 5 (L5) pyramidal neurons in the cortex. In this study, we examined the effects of sensory deprivation and motor learning on dendritic spine remodeling of layer 2/3 (L2/3) pyramidal neurons in the barrel and motor cortices. Similar to L5 pyramidal neurons, spines on apical dendrites of L2/3 pyramidal neurons are plastic during development and largely stable in adulthood. Sensory deprivation via whisker trimming reduces the elimination rate of existing spines without significant effect on the rate of spine formation in the developing barrel cortex. Furthermore, we show that motor training increases the formation and elimination of dendritic spines in the primary motor cortex. Unlike L5 pyramidal neurons, however, there is no significant difference in the rate of spine formation between sibling dendritic branches of L2/3 pyramidal neurons. Our studies indicate that sensory and motor learning experiences have important impact on dendritic spine remodeling in L2/3 pyramidal neurons. They also suggest that the rules governing experience-dependent spine remodeling are largely similar, but not identical, between L2/3 and L5 pyramidal neurons.
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Affiliation(s)
- Lei Ma
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Qian Qiao
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Jin-Wu Tsai
- Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA
| | - Guang Yang
- Department of Anesthesiology, New York University School of Medicine, New York, NY, 10016, USA
| | - Wei Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China
| | - Wen-Biao Gan
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, 518055, China.,Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016, USA
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364
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Zou C, Montagna E, Shi Y, Peters F, Blazquez-Llorca L, Shi S, Filser S, Dorostkar MM, Herms J. Intraneuronal APP and extracellular Aβ independently cause dendritic spine pathology in transgenic mouse models of Alzheimer's disease. Acta Neuropathol 2015; 129:909-20. [PMID: 25862638 PMCID: PMC4436699 DOI: 10.1007/s00401-015-1421-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Revised: 04/01/2015] [Accepted: 04/01/2015] [Indexed: 12/28/2022]
Abstract
Alzheimer’s disease (AD) is thought to be caused by accumulation of amyloid-β protein (Aβ), which is a cleavage product of amyloid precursor protein (APP). Transgenic mice overexpressing APP have been used to recapitulate amyloid-β pathology. Among them, APP23 and APPswe/PS1deltaE9 (deltaE9) mice are extensively studied. APP23 mice express APP with Swedish mutation and develop amyloid plaques late in their life, while cognitive deficits are observed in young age. In contrast, deltaE9 mice with mutant APP and mutant presenilin-1 develop amyloid plaques early but show typical cognitive deficits in old age. To unveil the reasons for different progressions of cognitive decline in these commonly used mouse models, we analyzed the number and turnover of dendritic spines as important structural correlates for learning and memory. Chronic in vivo two-photon imaging in apical tufts of layer V pyramidal neurons revealed a decreased spine density in 4–5-month-old APP23 mice. In age-matched deltaE9 mice, in contrast, spine loss was only observed on cortical dendrites that were in close proximity to amyloid plaques. In both cases, the reduced spine density was caused by decreased spine formation. Interestingly, the patterns of alterations in spine morphology differed between these two transgenic mouse models. Moreover, in APP23 mice, APP was found to accumulate intracellularly and its content was inversely correlated with the absolute spine density and the relative number of mushroom spines. Collectively, our results suggest that different pathological mechanisms, namely an intracellular accumulation of APP or extracellular amyloid plaques, may lead to spine abnormalities in young adult APP23 and deltaE9 mice, respectively. These distinct features, which may represent very different mechanisms of synaptic failure in AD, have to be taken into consideration when translating results from animal studies to the human disease.
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365
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Feld GB, Diekelmann S. Sleep smart-optimizing sleep for declarative learning and memory. Front Psychol 2015; 6:622. [PMID: 26029150 PMCID: PMC4428077 DOI: 10.3389/fpsyg.2015.00622] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Accepted: 04/27/2015] [Indexed: 02/05/2023] Open
Abstract
The last decade has witnessed a spurt of new publications documenting sleep's essential contribution to the brains ability to form lasting memories. For the declarative memory domain, slow wave sleep (the deepest sleep stage) has the greatest beneficial effect on the consolidation of memories acquired during preceding wakefulness. The finding that newly encoded memories become reactivated during subsequent sleep fostered the idea that reactivation leads to the strengthening and transformation of the memory trace. According to the active system consolidation account, trace reactivation leads to the redistribution of the transient memory representations from the hippocampus to the long-lasting knowledge networks of the cortex. Apart from consolidating previously learned information, sleep also facilitates the encoding of new memories after sleep, which probably relies on the renormalization of synaptic weights during sleep as suggested by the synaptic homeostasis theory. During wakefulness overshooting potentiation causes an imbalance in synaptic weights that is countered by synaptic downscaling during subsequent sleep. This review briefly introduces the basic concepts and central findings of the research on sleep and memory, and discusses implications of this lab-based work for everyday applications to make the best possible use of sleep's beneficial effect on learning and memory.
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Affiliation(s)
- Gordon B Feld
- Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
| | - Susanne Diekelmann
- Institute for Medical Psychology and Behavioral Neurobiology, University of Tübingen Tübingen, Germany
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366
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Blanco W, Pereira CM, Cota VR, Souza AC, Rennó-Costa C, Santos S, Dias G, Guerreiro AMG, Tort ABL, Neto AD, Ribeiro S. Synaptic Homeostasis and Restructuring across the Sleep-Wake Cycle. PLoS Comput Biol 2015; 11:e1004241. [PMID: 26020963 PMCID: PMC4447375 DOI: 10.1371/journal.pcbi.1004241] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/14/2015] [Indexed: 01/12/2023] Open
Abstract
Sleep is critical for hippocampus-dependent memory consolidation. However, the underlying mechanisms of synaptic plasticity are poorly understood. The central controversy is on whether long-term potentiation (LTP) takes a role during sleep and which would be its specific effect on memory. To address this question, we used immunohistochemistry to measure phosphorylation of Ca2+/calmodulin-dependent protein kinase II (pCaMKIIα) in the rat hippocampus immediately after specific sleep-wake states were interrupted. Control animals not exposed to novel objects during waking (WK) showed stable pCaMKIIα levels across the sleep-wake cycle, but animals exposed to novel objects showed a decrease during subsequent slow-wave sleep (SWS) followed by a rebound during rapid-eye-movement sleep (REM). The levels of pCaMKIIα during REM were proportional to cortical spindles near SWS/REM transitions. Based on these results, we modeled sleep-dependent LTP on a network of fully connected excitatory neurons fed with spikes recorded from the rat hippocampus across WK, SWS and REM. Sleep without LTP orderly rescaled synaptic weights to a narrow range of intermediate values. In contrast, LTP triggered near the SWS/REM transition led to marked swaps in synaptic weight ranking. To better understand the interaction between rescaling and restructuring during sleep, we implemented synaptic homeostasis and embossing in a detailed hippocampal-cortical model with both excitatory and inhibitory neurons. Synaptic homeostasis was implemented by weakening potentiation and strengthening depression, while synaptic embossing was simulated by evoking LTP on selected synapses. We observed that synaptic homeostasis facilitates controlled synaptic restructuring. The results imply a mechanism for a cognitive synergy between SWS and REM, and suggest that LTP at the SWS/REM transition critically influences the effect of sleep: Its lack determines synaptic homeostasis, its presence causes synaptic restructuring.
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Affiliation(s)
- Wilfredo Blanco
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- Department of Computer and Automation, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- Department of Computer Science, State University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Catia M. Pereira
- Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Rio Grande do Norte, Brazil
| | - Vinicius R. Cota
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
- Laboratory of Neuroengineerging and Neuroscience, Federal University of São João Del-Rei, São João Del-Rei, Minas Gerais, Brazil
| | - Annie C. Souza
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - César Rennó-Costa
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sharlene Santos
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Gabriella Dias
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Ana M. G. Guerreiro
- Department of Biomedical Engineering, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Adriano B. L. Tort
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Adrião D. Neto
- Department of Computer and Automation, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
| | - Sidarta Ribeiro
- Brain Institute, Federal University of Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil
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367
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Cichon J, Gan WB. Branch-specific dendritic Ca(2+) spikes cause persistent synaptic plasticity. Nature 2015; 520:180-5. [PMID: 25822789 DOI: 10.1038/nature14251] [Citation(s) in RCA: 296] [Impact Index Per Article: 32.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 01/21/2015] [Indexed: 02/07/2023]
Abstract
The brain has an extraordinary capacity for memory storage, but how it stores new information without disrupting previously acquired memories remains unknown. Here we show that different motor learning tasks induce dendritic Ca(2+) spikes on different apical tuft branches of individual layer V pyramidal neurons in the mouse motor cortex. These task-related, branch-specific Ca(2+) spikes cause long-lasting potentiation of postsynaptic dendritic spines active at the time of spike generation. When somatostatin-expressing interneurons are inactivated, different motor tasks frequently induce Ca(2+) spikes on the same branches. On those branches, spines potentiated during one task are depotentiated when they are active seconds before Ca(2+) spikes induced by another task. Concomitantly, increased neuronal activity and performance improvement after learning one task are disrupted when another task is learned. These findings indicate that dendritic-branch-specific generation of Ca(2+) spikes is crucial for establishing long-lasting synaptic plasticity, thereby facilitating information storage associated with different learning experiences.
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Affiliation(s)
- Joseph Cichon
- Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, New York 10016, USA
| | - Wen-Biao Gan
- Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, New York 10016, USA
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368
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Abstract
Large-amplitude sleep slow oscillations group faster neuronal oscillations and are of functional relevance for memory performance. However, relatively little is known about the impact of slow oscillations on functionally coupled networks. Here, we provide a comprehensive view on how human slow oscillatory dynamics influence various measures of brain processing. We demonstrate that slow oscillations coordinate interregional cortical communication, as assessed by phase synchrony in the sleep spindle frequency range and cross-frequency coupling between spindle and beta activity. Furthermore, we show that the organizing role of slow oscillations is restricted to circumscribed topographical areas. These findings add importantly to our basic understanding of the orchestrating role of slow oscillations. In addition, they are of considerable relevance for accounts of sleep-dependent memory reprocessing and consolidation.
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369
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Kastellakis G, Cai DJ, Mednick SC, Silva AJ, Poirazi P. Synaptic clustering within dendrites: an emerging theory of memory formation. Prog Neurobiol 2015; 126:19-35. [PMID: 25576663 PMCID: PMC4361279 DOI: 10.1016/j.pneurobio.2014.12.002] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 12/29/2014] [Accepted: 12/29/2014] [Indexed: 11/30/2022]
Abstract
It is generally accepted that complex memories are stored in distributed representations throughout the brain, however the mechanisms underlying these representations are not understood. Here, we review recent findings regarding the subcellular mechanisms implicated in memory formation, which provide evidence for a dendrite-centered theory of memory. Plasticity-related phenomena which affect synaptic properties, such as synaptic tagging and capture, synaptic clustering, branch strength potentiation and spinogenesis provide the foundation for a model of memory storage that relies heavily on processes operating at the dendrite level. The emerging picture suggests that clusters of functionally related synapses may serve as key computational and memory storage units in the brain. We discuss both experimental evidence and theoretical models that support this hypothesis and explore its advantages for neuronal function.
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Affiliation(s)
- George Kastellakis
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1385, GR 70013 Heraklion, Greece
| | - Denise J Cai
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, UCLA, 2554 Gonda Center, Los Angeles, CA 90095, United States
| | - Sara C Mednick
- Department of Psychology, University of California, 900 University Avenue, Riverside, CA 92521, United States
| | - Alcino J Silva
- Departments of Neurobiology, Psychology, Psychiatry, Integrative Center for Learning and Memory and Brain Research Institute, UCLA, 2554 Gonda Center, Los Angeles, CA 90095, United States
| | - Panayiota Poirazi
- Institute of Molecular Biology and Biotechnology (IMBB), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1385, GR 70013 Heraklion, Greece.
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370
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Xie M, Yan J, He C, Yang L, Tan G, Li C, Hu Z, Wang J. Short-term sleep deprivation impairs spatial working memory and modulates expression levels of ionotropic glutamate receptor subunits in hippocampus. Behav Brain Res 2015; 286:64-70. [PMID: 25732956 DOI: 10.1016/j.bbr.2015.02.040] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 02/18/2015] [Accepted: 02/22/2015] [Indexed: 11/29/2022]
Abstract
Hippocampus-dependent learning memory is sensitive to sleep deprivation (SD). Although the ionotropic glutamate receptors play a vital role in synaptic plasticity and learning and memory, however, whether the expression of these receptor subunits is modulated by sleep loss remains unclear. In the present study, western blotting was performed by probing with specific antibodies against the ionotropic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1, GluA2, GluA3, and against the N-methyl-d-aspartate (NMDA) glutamate receptor subunits GluN1, GluN2A, GluN2B. In hippocampus, down regulation of surface GluA1 and GluN2A surface expression were observed in both SD groups. However, surface expression level of GluA2, GluA3, GluN1 and GluN2B was significantly up-regulated in 8h-SD rats when compared to the 4h-SD rats. In parallel with the complex changes in AMPA and NMDA receptor subunit expressions, we found the 8h-SD impaired rat spatial working memory in 30-s-delay T-maze task, whereas no impairment of spatial learning was observed in 4h-SD rats. These results indicate that sleep loss alters the relative expression levels of the AMPA and NMDA receptors, thus affects the synaptic strength and capacity for plasticity and partially contributes to spatial memory impairment.
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Affiliation(s)
- Meilan Xie
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Jie Yan
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Chao He
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Li Yang
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Gang Tan
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Chao Li
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China
| | - Zhian Hu
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China.
| | - Jiali Wang
- Department of Physiology, Third Military Medical University, Chongqing 400038, PR China.
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371
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Borragán G, Urbain C, Schmitz R, Mary A, Peigneux P. Sleep and memory consolidation: motor performance and proactive interference effects in sequence learning. Brain Cogn 2015; 95:54-61. [PMID: 25682352 DOI: 10.1016/j.bandc.2015.01.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 01/16/2015] [Accepted: 01/23/2015] [Indexed: 11/19/2022]
Abstract
That post-training sleep supports the consolidation of sequential motor skills remains debated. Performance improvement and sensitivity to proactive interference are both putative measures of long-term memory consolidation. We tested sleep-dependent memory consolidation for visuo-motor sequence learning using a proactive interference paradigm. Thirty-three young adults were trained on sequence A on Day 1, then had Regular Sleep (RS) or were Sleep Deprived (SD) on the night after learning. After two recovery nights, they were tested on the same sequence A, then had to learn a novel, potentially competing sequence B. We hypothesized that proactive interference effects on sequence B due to the prior learning of sequence A would be higher in the RS condition, considering that proactive interference is an indirect marker of the robustness of sequence A, which should be better consolidated over post-training sleep. Results highlighted sleep-dependent improvement for sequence A, with faster RTs overnight for RS participants only. Moreover, the beneficial impact of sleep was specific to the consolidation of motor but not sequential skills. Proactive interference effects on learning a new material at Day 4 were similar between RS and SD participants. These results suggest that post-training sleep contributes to optimizing motor but not sequential components of performance in visuo-motor sequence learning.
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Affiliation(s)
- Guillermo Borragán
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles (ULB) and UNI - ULB Neurosciences Institute, Brussels, Belgium.
| | - Charline Urbain
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles (ULB) and UNI - ULB Neurosciences Institute, Brussels, Belgium; Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Canada; Neuroscience & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Rémy Schmitz
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles (ULB) and UNI - ULB Neurosciences Institute, Brussels, Belgium; LABNIC - Laboratory for Neurology and Imaging of Cognition, Department of Neurosciences, Campus Biotech, University of Geneva (UNIGE), Geneva, Switzerland
| | - Alison Mary
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles (ULB) and UNI - ULB Neurosciences Institute, Brussels, Belgium
| | - Philippe Peigneux
- UR2NF - Neuropsychology and Functional Neuroimaging Research Group at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles (ULB) and UNI - ULB Neurosciences Institute, Brussels, Belgium.
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372
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Ebus SCM, IJff DM, den Boer JT, van Hall MJH, Klinkenberg S, van der Does A, Boon PJ, Arends JBAM, Aldenkamp AP. Changes in the frequency of benign focal spikes accompany changes in central information processing speed: a prospective 2-year follow-up study. Epilepsy Behav 2015; 43:8-15. [PMID: 25546731 DOI: 10.1016/j.yebeh.2014.11.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Revised: 11/20/2014] [Accepted: 11/21/2014] [Indexed: 11/28/2022]
Abstract
We prospectively examined whether changes in the frequency of benign focal spikes accompany changes in cognition. Twenty-six children with benign focal spikes (19 with Rolandic epilepsy) and learning difficulties were examined with repeated 24-hour EEG recordings, three cognitive tests on central information processing speed (CIPS), and questionnaires on cognition and behavior at baseline, 6months, and 2years. Antiepileptic drug changes were allowed when estimated necessary by the treating physician. At baseline, a lower CIPS was correlated with a higher frequency of diurnal interictal epileptiform discharges (IEDs) and with worse academic achievement. At follow-up, there was a significant correlation between changes in CIPS and EEG changes in wakefulness (in the same direction) when the EEG outcome was dichotomized in IED frequency "increased" or "not increased". Behavioral problems were more often observed in patients with higher frequency of IEDs in sleep at baseline and in those with ongoing IEDs compared with those with EEG remission (without or with sporadic IEDs in the recording) at the end of the study period. No changes were observed in the results of the questionnaires. A lower diurnal IED frequency at baseline, lack of serial IEDs, and occurrence of only unilateral IEDs were correlated with a higher chance of EEG remission at 2-year follow-up. Electroencephalography remission could not be predicted from other epilepsy variables except from seizure freedom in the last six months. Our results confirm the nonbenign character of 'benign' focal spikes. Whether an early and stable EEG remission can be achieved through antiepileptic treatment and whether this is of benefit for cognitive development should be examined in prospective placebo-controlled randomized trials.
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Affiliation(s)
- S C M Ebus
- Epilepsy Kempenhaeghe, Heeze, The Netherlands.
| | - D M IJff
- Epilepsy Kempenhaeghe, Heeze, The Netherlands
| | | | | | - S Klinkenberg
- Department of Neurology, Maastricht University Hospital, Maastricht, The Netherlands
| | | | - P J Boon
- Epilepsy Kempenhaeghe, Heeze, The Netherlands; Department of Neurology, Ghent University Hospital, Ghent, Belgium
| | - J B A M Arends
- Epilepsy Kempenhaeghe, Heeze, The Netherlands; Faculty of Electrical Engineering, University of Technology, Eindhoven, The Netherlands
| | - A P Aldenkamp
- Epilepsy Kempenhaeghe, Heeze, The Netherlands; Department of Neurology, Maastricht University Hospital, Maastricht, The Netherlands; Department of Neurology, Ghent University Hospital, Ghent, Belgium; Faculty of Electrical Engineering, University of Technology, Eindhoven, The Netherlands
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373
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The role of rapid eye movement sleep for amygdala-related memory processing. Neurobiol Learn Mem 2015; 122:110-21. [PMID: 25638277 DOI: 10.1016/j.nlm.2015.01.008] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 12/19/2014] [Accepted: 01/19/2015] [Indexed: 01/01/2023]
Abstract
Over the years, rapid eye movement (REM) sleep has been associated with general memory consolidation, specific consolidation of perceptual, procedural, emotional and fear memories, brain maturation and preparation of waking consciousness. More recently, some of these associations (e.g., general and procedural memory consolidation) have been shown to be unlikely, while others (e.g., brain maturation and consciousness) remain inconclusive. In this review, we argue that both behavioral and neurophysiological evidence supports a role of REM sleep for amygdala-related memory processing: the amygdala-hippocampus-medial prefrontal cortex network involved in emotional processing, fear memory and valence consolidation shows strongest activity during REM sleep, in contrast to the hippocampus-medial prefrontal cortex only network which is more active during non-REM sleep. However, more research is needed to fully understand the mechanisms.
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374
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Calais JB, Ojopi EB, Morya E, Sameshima K, Ribeiro S. Experience-dependent upregulation of multiple plasticity factors in the hippocampus during early REM sleep. Neurobiol Learn Mem 2015; 122:19-27. [PMID: 25626078 DOI: 10.1016/j.nlm.2015.01.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 12/26/2014] [Accepted: 01/05/2015] [Indexed: 11/16/2022]
Abstract
Sleep is beneficial to learning, but the underlying mechanisms remain controversial. The synaptic homeostasis hypothesis (SHY) proposes that the cognitive function of sleep is related to a generalized rescaling of synaptic weights to intermediate levels, due to a passive downregulation of plasticity mechanisms. A competing hypothesis proposes that the active upscaling and downscaling of synaptic weights during sleep embosses memories in circuits respectively activated or deactivated during prior waking experience, leading to memory changes beyond rescaling. Both theories have empirical support but the experimental designs underlying the conflicting studies are not congruent, therefore a consensus is yet to be reached. To advance this issue, we used real-time PCR and electrophysiological recordings to assess gene expression related to synaptic plasticity in the hippocampus and primary somatosensory cortex of rats exposed to novel objects, then kept awake (WK) for 60 min and finally killed after a 30 min period rich in WK, slow-wave sleep (SWS) or rapid-eye-movement sleep (REM). Animals similarly treated but not exposed to novel objects were used as controls. We found that the mRNA levels of Arc, Egr1, Fos, Ppp2ca and Ppp2r2d were significantly increased in the hippocampus of exposed animals allowed to enter REM, in comparison with control animals. Experience-dependent changes during sleep were not significant in the hippocampus for Bdnf, Camk4, Creb1, and Nr4a1, and no differences were detected between exposed and control SWS groups for any of the genes tested. No significant changes in gene expression were detected in the primary somatosensory cortex during sleep, in contrast with previous studies using longer post-stimulation intervals (>180 min). The experience-dependent induction of multiple plasticity-related genes in the hippocampus during early REM adds experimental support to the synaptic embossing theory.
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Affiliation(s)
- Julien Braga Calais
- Laboratório de Neurociências (LIM/27), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (USP), Departamento e Instituto de Psiquiatria, São Paulo, Brazil; Laboratório Cesar Timo-Iaria, Instituto de Ensino e Pesquisa, Hospital Sírio-Libanês, São Paulo, Brazil
| | - Elida Benquique Ojopi
- Laboratório de Neurociências (LIM/27), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (USP), Departamento e Instituto de Psiquiatria, São Paulo, Brazil
| | - Edgard Morya
- Laboratório Cesar Timo-Iaria, Instituto de Ensino e Pesquisa, Hospital Sírio-Libanês, São Paulo, Brazil; Edmond and Lily Safra International Institute of Neuroscience of Natal (ELS-IINN), Natal, Brazil
| | - Koichi Sameshima
- Laboratório Cesar Timo-Iaria, Instituto de Ensino e Pesquisa, Hospital Sírio-Libanês, São Paulo, Brazil; Departamento de Radiologia e Oncologia, Faculdade de Medicina da Universidade de São Paulo (USP), São Paulo, Brazil.
| | - Sidarta Ribeiro
- Instituto do Cérebro, Universidade Federal do Rio Grande do Norte (UFRN), Natal, Brazil.
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375
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Silasi G, Murphy TH. Stroke and the connectome: how connectivity guides therapeutic intervention. Neuron 2015; 83:1354-68. [PMID: 25233317 DOI: 10.1016/j.neuron.2014.08.052] [Citation(s) in RCA: 140] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2014] [Indexed: 11/30/2022]
Abstract
Connections between neurons are affected within 3 min of stroke onset by massive ischemic depolarization and then delayed cell death. Some connections can recover with prompt reperfusion; others associated with the dying infarct do not. Disruption in functional connectivity is due to direct tissue loss and indirect disconnections of remote areas known as diaschisis. Stroke is devastating, yet given the brain's redundant design, collateral surviving networks and their connections are well-positioned to compensate. Our perspective is that new treatments for stroke may involve a rational functional and structural connections-based approach. Surviving, affected, and at-risk networks can be identified and targeted with scenario-specific treatments. Strategies for recovery may include functional inhibition of the intact hemisphere, rerouting of connections, or setpoint-mediated network plasticity. These approaches may be guided by brain imaging and enabled by patient- and injury-specific brain stimulation, rehabilitation, and potential molecule-based strategies to enable new connections.
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Affiliation(s)
- Gergely Silasi
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Timothy H Murphy
- Department of Psychiatry, Kinsmen Laboratory of Neurological Research, University of British Columbia, Vancouver, BC V6T 1Z3, Canada; Brain Research Centre, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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376
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Sau Wan Lai C. Intravital imaging of dendritic spine plasticity. INTRAVITAL 2015; 3:e944439. [PMID: 28243511 DOI: 10.4161/21659087.2014.984504] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 10/22/2014] [Accepted: 10/22/2014] [Indexed: 11/19/2022]
Abstract
Dendritic spines are the postsynaptic part of most excitatory synapses in the mammalian brain. Recent works have suggested that the structural and functional plasticity of dendritic spines have been associated with information coding and memories. Advances in imaging and labeling techniques enable the study of dendritic spine dynamics in vivo. This perspective focuses on intravital imaging studies of dendritic spine plasticity in the neocortex. I will introduce imaging tools for studying spine dynamics and will further review current findings on spine structure and function under various physiological and pathological conditions.
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Affiliation(s)
- Cora Sau Wan Lai
- Department of Physiology; Li Ka Shing Faculty of Medicine; The University of Hong Kong ; Pokfulam, Hong Kong SAR
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377
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Cirelli C, Tononi G. Sleep and synaptic homeostasis. Sleep 2015; 38:161-2. [PMID: 25325499 DOI: 10.5665/sleep.4348] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Accepted: 09/26/2014] [Indexed: 02/03/2023] Open
Affiliation(s)
- Chiara Cirelli
- Department of Psychiatry, University of Wisconsin, Madison, WI
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, WI
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378
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Scullin MK, Bliwise DL. Sleep, cognition, and normal aging: integrating a half century of multidisciplinary research. PERSPECTIVES ON PSYCHOLOGICAL SCIENCE 2015; 10:97-137. [PMID: 25620997 PMCID: PMC4302758 DOI: 10.1177/1745691614556680] [Citation(s) in RCA: 290] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sleep is implicated in cognitive functioning in young adults. With increasing age, there are substantial changes to sleep quantity and quality, including changes to slow-wave sleep, spindle density, and sleep continuity/fragmentation. A provocative question for the field of cognitive aging is whether such changes in sleep physiology affect cognition (e.g., memory consolidation). We review nearly a half century of research across seven diverse correlational and experimental domains that historically have had little crosstalk. Broadly speaking, sleep and cognitive functions are often related in advancing age, though the prevalence of null effects in healthy older adults (including correlations in the unexpected, negative direction) indicates that age may be an effect modifier of these associations. We interpret the literature as suggesting that maintaining good sleep quality, at least in young adulthood and middle age, promotes better cognitive functioning and serves to protect against age-related cognitive declines.
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Affiliation(s)
- Michael K Scullin
- Department of Psychology and Neuroscience, Baylor University Department of Neurology, Emory University School of Medicine
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379
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Ravassard P, Hamieh AM, Malleret G, Salin PA. Paradoxical sleep: A vigilance state to gate long-term brain plasticity? Neurobiol Learn Mem 2014; 122:4-10. [PMID: 25448317 DOI: 10.1016/j.nlm.2014.11.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/11/2014] [Accepted: 11/19/2014] [Indexed: 12/11/2022]
Abstract
Memory consolidation is the process for long-term storage of information and protection against interferences. It has been proposed that long-term potentiation (LTP), the long-lasting enhancement of synaptic transmission, is a cellular model for memory consolidation. Since consolidation of several forms of memory is facilitated by paradoxical sleep (PS) we ask whether PS modulates the cellular and molecular pathways underlying LTP. The long-lasting form of LTP (L-LTP) is dependent on the activation of transcription factors, enzymatic cascades and the secreted neurotrophin BDNF. By using PS deprivation, immunohistochemistry and quantitative real-time polymerase chain reaction (qPCR), we showed that an increase in PS amount (produced by rebound in PS deprived rats) is able to up-regulate the expression level of transcription factors Zif268 and c-Fos as well as Arc and BDNF in the CA1 and CA3 areas of the hippocampus. Several studies involved these factors in dendritic protein synthesis and in long-term structural changes of synapses underlying L-LTP. The present study together with the work of others (Ribeiro et al., 2002) suggest that by this mechanism, a post-learning increase in PS quantity (post-learning PS window) could convert a transient form of LTP to L-LTP.
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Affiliation(s)
- Pascal Ravassard
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, France; Physiopathology of the Sleep Neuronal Networks, Lyon Neuroscience Research Center, F-69008 Lyon, France; University Lyon 1, F-69000 Lyon, France
| | - Al Mahdy Hamieh
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, France; Physiopathology of the Sleep Neuronal Networks, Lyon Neuroscience Research Center, F-69008 Lyon, France; University Lyon 1, F-69000 Lyon, France
| | - Gaël Malleret
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, France; Physiopathology of the Sleep Neuronal Networks, Lyon Neuroscience Research Center, F-69008 Lyon, France; University Lyon 1, F-69000 Lyon, France
| | - Paul-Antoine Salin
- Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 5292, Institut National de la Santé et de la Recherche Médicale (INSERM), Unité 1028, France; Physiopathology of the Sleep Neuronal Networks, Lyon Neuroscience Research Center, F-69008 Lyon, France; University Lyon 1, F-69000 Lyon, France.
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380
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Gabitov E, Manor D, Karni A. Patterns of modulation in the activity and connectivity of motor cortex during the repeated generation of movement sequences. J Cogn Neurosci 2014; 27:736-51. [PMID: 25390206 DOI: 10.1162/jocn_a_00751] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
It is not clear how the engagement of motor mnemonic processes is expressed in online brain activity. We scanned participants, using fMRI, during the paced performance of a finger-to-thumb opposition sequence (FOS), intensively trained a day earlier (T-FOS), and a similarly constructed, but novel, untrained FOS (U-FOS). Both movement sequences were performed in pairs of blocks separated by a brief rest interval (30 sec). We have recently shown that in the primary motor cortex (M1) motor memory was not expressed in the average signal intensity but rather in the across-block signal modulations, that is, when comparing the first to the second performance block across the brief rest interval. Here, using an M1 seed, we show that for the T-FOS, the M1-striatum functional connectivity decreased across blocks; however, for the U-FOS, connectivity within the M1 and between M1 and striatum increased. In addition, in M1, the pattern of within-block signal change, but not signal variability per se, reliably differentiated the two sequences. Only for the U-FOS and only within the first blocks in each pair, the signal significantly decreased. No such modulation was found within the second corresponding blocks following the brief rest interval in either FOS. We propose that a network including M1 and striatum underlies online motor working memory. This network may promote a transient integrated representation of a new movement sequence and readily retrieves a previously established movement sequence representation. Averaging over single events or blocks may not capture the dynamics of motor representations that occur over multiple timescales.
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381
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Hodor A, Palchykova S, Baracchi F, Noain D, Bassetti CL. Baclofen facilitates sleep, neuroplasticity, and recovery after stroke in rats. Ann Clin Transl Neurol 2014; 1:765-77. [PMID: 25493268 PMCID: PMC4241804 DOI: 10.1002/acn3.115] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/22/2014] [Accepted: 08/15/2014] [Indexed: 01/10/2023] Open
Abstract
OBJECTIVE Sleep disruption in the acute phase after stroke has detrimental effects on recovery in both humans and animals. Conversely, the effect of sleep promotion remains unclear. Baclofen (Bac) is a known non-rapid eye movement (NREM) sleep-promoting drug in both humans and animals. The aim of this study was to investigate the effect of Bac on stroke recovery in a rat model of focal cerebral ischemia (isch). METHODS Rats, assigned to three experimental groups (Bac/isch, saline/isch, or Bac/sham), were injected twice daily for 10 consecutive days with Bac or saline, starting 24 h after induction of stroke. The sleep-wake cycle was assessed by EEG recordings and functional motor recovery by single pellet reaching test (SPR). In order to identify potential neuroplasticity mechanisms, axonal sprouting and neurogenesis were evaluated. Brain damage was assessed by Nissl staining. RESULTS Repeated Bac treatment after ischemia affected sleep, motor function, and neuroplasticity, but not the size of brain damage. NREM sleep amount was increased significantly during the dark phase in Bac/isch compared to the saline/isch group. SPR performance dropped to 0 immediately after stroke and was recovered slowly thereafter in both ischemic groups. However, Bac-treated ischemic rats performed significantly better than saline-treated animals. Axonal sprouting in the ipsilesional motor cortex and striatum, and neurogenesis in the peri-infarct region were significantly increased in Bac/isch group. CONCLUSION Delayed repeated Bac treatment after stroke increased NREM sleep and promoted both neuroplasticity and functional outcome. These data support the hypothesis of the role of sleep as a modulator of poststroke recovery.
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Affiliation(s)
- Aleksandra Hodor
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital 3010, Bern, Switzerland
| | - Svitlana Palchykova
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital 3010, Bern, Switzerland
| | - Francesca Baracchi
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital 3010, Bern, Switzerland
| | - Daniela Noain
- Department of Neurology, University Hospital Zürich 8091, Zürich, Switzerland
| | - Claudio L Bassetti
- Center for Experimental Neurology (ZEN), Department of Neurology, Inselspital, Bern University Hospital 3010, Bern, Switzerland
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382
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Luck JM, Mehta A. Slow synaptic dynamics in a network: from exponential to power-law forgetting. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2014; 90:032709. [PMID: 25314475 DOI: 10.1103/physreve.90.032709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Indexed: 06/04/2023]
Abstract
We investigate a mean-field model of interacting synapses on a directed neural network. Our interest lies in the slow adaptive dynamics of synapses, which are driven by the fast dynamics of the neurons they connect. Cooperation is modeled from the usual Hebbian perspective, while competition is modeled by an original polarity-driven rule. The emergence of a critical manifold culminating in a tricritical point is crucially dependent on the presence of synaptic competition. This leads to a universal 1/t power-law relaxation of the mean synaptic strength along the critical manifold and an equally universal 1/√[t] relaxation at the tricritical point, to be contrasted with the exponential relaxation that is otherwise generic. In turn, this leads to the natural emergence of long- and short-term memory from different parts of parameter space in a synaptic network, which is the most original and important result of our present investigations.
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Affiliation(s)
- J M Luck
- Institut de Physique Théorique, URA 2306 of CNRS, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - A Mehta
- S. N. Bose National Centre for Basic Sciences, Block JD, Sector 3, Salt Lake, Calcutta 700098, India
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383
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Frank MG, Cantera R. Sleep, clocks, and synaptic plasticity. Trends Neurosci 2014; 37:491-501. [PMID: 25087980 PMCID: PMC4152403 DOI: 10.1016/j.tins.2014.06.005] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/12/2014] [Accepted: 06/30/2014] [Indexed: 01/24/2023]
Abstract
Sleep is widely believed to play an essential role in synaptic plasticity. However, the precise mechanisms governing this presumptive function are largely unknown. There is also evidence for independent circadian oscillations in synaptic strength and morphology. Therefore, synaptic changes observed after sleep reflect interactions between state-dependent (e.g., wake versus sleep) and state-independent (circadian) processes. In this review we consider how sleep and biological clocks influence synaptic plasticity. We discuss these findings in the context of current plasticity-based theories of sleep function and propose a new model that integrates circadian and brain-state influences on synaptic plasticity.
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Affiliation(s)
- Marcos G. Frank
- Department of Neuroscience Perelman School of Medicine University of Pennsylvania Philadelphia, PA 19104
| | - Rafael Cantera
- Zoology Department Stockholm University Stockholm, Sweden Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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