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Cabrera Y, Koymans KJ, Poe GR, Kessels HW, Van Someren EJW, Wassing R. Overnight neuronal plasticity and adaptation to emotional distress. Nat Rev Neurosci 2024; 25:253-271. [PMID: 38443627 DOI: 10.1038/s41583-024-00799-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/01/2024] [Indexed: 03/07/2024]
Abstract
Expressions such as 'sleep on it' refer to the resolution of distressing experiences across a night of sound sleep. Sleep is an active state during which the brain reorganizes the synaptic connections that form memories. This Perspective proposes a model of how sleep modifies emotional memory traces. Sleep-dependent reorganization occurs through neurophysiological events in neurochemical contexts that determine the fates of synapses to grow, to survive or to be pruned. We discuss how low levels of acetylcholine during non-rapid eye movement sleep and low levels of noradrenaline during rapid eye movement sleep provide a unique window of opportunity for plasticity in neuronal representations of emotional memories that resolves the associated distress. We integrate sleep-facilitated adaptation over three levels: experience and behaviour, neuronal circuits, and synaptic events. The model generates testable hypotheses for how failed sleep-dependent adaptation to emotional distress is key to mental disorders, notably disorders of anxiety, depression and post-traumatic stress with the common aetiology of insomnia.
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Affiliation(s)
- Yesenia Cabrera
- Department of Integrative Biology and Physiology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Karin J Koymans
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Gina R Poe
- Department of Integrative Biology and Physiology, Brain Research Institute, University of California Los Angeles, Los Angeles, CA, USA
| | - Helmut W Kessels
- Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
- Department of Synaptic Plasticity and Behaviour, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Society for Arts and Sciences, Amsterdam, Netherlands
| | - Eus J W Van Someren
- Department of Sleep and Cognition, Netherlands Institute for Neuroscience, An Institute of the Royal Netherlands Society for Arts and Sciences, Amsterdam, Netherlands
- Department of Integrative Neurophysiology and Psychiatry, VU University, Amsterdam UMC, Amsterdam, Netherlands
- Center for Neurogenomics and Cognitive Research, VU University, Amsterdam UMC, Amsterdam, Netherlands
| | - Rick Wassing
- Sleep and Circadian Research, Woolcock Institute of Medical Research, Macquarie University, Sydney, New South Wales, Australia.
- School of Psychological Sciences, Faculty of Medicine Health and Human Sciences, Macquarie University, Sydney, New South Wales, Australia.
- Sydney Local Health District, Sydney, New South Wales, Australia.
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2
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Gao JX, Yan G, Li XX, Xie JF, Spruyt K, Shao YF, Hou YP. The Ponto-Geniculo-Occipital (PGO) Waves in Dreaming: An Overview. Brain Sci 2023; 13:1350. [PMID: 37759951 PMCID: PMC10526299 DOI: 10.3390/brainsci13091350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 09/11/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
Rapid eye movement (REM) sleep is the main sleep correlate of dreaming. Ponto-geniculo-occipital (PGO) waves are a signature of REM sleep. They represent the physiological mechanism of REM sleep that specifically limits the processing of external information. PGO waves look just like a message sent from the pons to the lateral geniculate nucleus of the visual thalamus, the occipital cortex, and other areas of the brain. The dedicated visual pathway of PGO waves can be interpreted by the brain as visual information, leading to the visual hallucinosis of dreams. PGO waves are considered to be both a reflection of REM sleep brain activity and causal to dreams due to their stimulation of the cortex. In this review, we summarize the role of PGO waves in potential neural circuits of two major theories, i.e., (1) dreams are generated by the activation of neural activity in the brainstem; (2) PGO waves signaling to the cortex. In addition, the potential physiological functions during REM sleep dreams, such as memory consolidation, unlearning, and brain development and plasticity and mood regulation, are discussed. It is hoped that our review will support and encourage research into the phenomenon of human PGO waves and their possible functions in dreaming.
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Affiliation(s)
- Jin-Xian Gao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
| | - Guizhong Yan
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
| | - Xin-Xuan Li
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
| | - Jun-Fan Xie
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
| | - Karen Spruyt
- NeuroDiderot-INSERM, Université de Paris, 75019 Paris, France;
| | - Yu-Feng Shao
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
| | - Yi-Ping Hou
- Key Laboratory of Preclinical Study for New Drugs of Gansu Province, Departments of Neuroscience, Anatomy, Histology, and Embryology, School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China; (J.-X.G.); (G.Y.); (X.-X.L.); (J.-F.X.)
- Sleep Medicine Center of Gansu Provincial Hospital, Lanzhou 730000, China
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3
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Schott AL, Baik J, Chung S, Weber F. A medullary hub for controlling REM sleep and pontine waves. Nat Commun 2023; 14:3922. [PMID: 37400467 DOI: 10.1038/s41467-023-39496-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/07/2023] [Indexed: 07/05/2023] Open
Abstract
Rapid-eye-movement (REM) sleep is a distinct behavioral state associated with vivid dreaming and memory processing. Phasic bursts of electrical activity, measurable as spike-like pontine (P)-waves, are a hallmark of REM sleep implicated in memory consolidation. However, the brainstem circuits regulating P-waves, and their interactions with circuits generating REM sleep, remain largely unknown. Here, we show that an excitatory population of dorsomedial medulla (dmM) neurons expressing corticotropin-releasing-hormone (CRH) regulates both REM sleep and P-waves in mice. Calcium imaging showed that dmM CRH neurons are selectively activated during REM sleep and recruited during P-waves, and opto- and chemogenetic experiments revealed that this population promotes REM sleep. Chemogenetic manipulation also induced prolonged changes in P-wave frequency, while brief optogenetic activation reliably triggered P-waves along with transiently accelerated theta oscillations in the electroencephalogram (EEG). Together, these findings anatomically and functionally delineate a common medullary hub for the regulation of both REM sleep and P-waves.
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Affiliation(s)
- Amanda L Schott
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Justin Baik
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shinjae Chung
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Franz Weber
- Department of Neuroscience, Perelman School of Medicine, Chronobiology and Sleep Institute, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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4
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Abstract
Sleep homeostasis is a complex neurobiologic phenomenon involving a number of molecular pathways, neurotransmitter release, synaptic activity, and factors modulating neural networks. Sleep plasticity allows for homeostatic optimization of neural networks and the replay-based consolidation of specific circuits, especially important for cognition, behavior, and information processing. Furthermore, research is currently moving from an essentially brain-focused to a more comprehensive view involving other systems, such as the immune system, hormonal status, and metabolic pathways. When dysfunctional, these systems contribute to sleep loss and fragmentation as well as to sleep need. In this chapter, the implications of neural plasticity and sleep homeostasis for the diagnosis and treatment of some major sleep disorders, such as insomnia and sleep deprivation, obstructive sleep apnea syndrome, restless legs syndrome, REM sleep behavior disorder, and narcolepsy are discussed in detail with their therapeutical implications. This chapter highlights that sleep is necessary for the maintenance of an optimal brain function and is sensitive to both genetic background and environmental enrichment. Even in pathologic conditions, sleep acts as a resilient plastic state that consolidates prior information and prioritizes network activity for efficient brain functioning.
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5
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Coupling of hippocampal theta and ripples with pontogeniculooccipital waves. Nature 2020; 589:96-102. [PMID: 33208951 DOI: 10.1038/s41586-020-2914-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 09/01/2020] [Indexed: 02/07/2023]
Abstract
The hippocampus has a major role in encoding and consolidating long-term memories, and undergoes plastic changes during sleep1. These changes require precise homeostatic control by subcortical neuromodulatory structures2. The underlying mechanisms of this phenomenon, however, remain unknown. Here, using multi-structure recordings in macaque monkeys, we show that the brainstem transiently modulates hippocampal network events through phasic pontine waves known as pontogeniculooccipital waves (PGO waves). Two physiologically distinct types of PGO wave appear to occur sequentially, selectively influencing high-frequency ripples and low-frequency theta events, respectively. The two types of PGO wave are associated with opposite hippocampal spike-field coupling, prompting periods of high neural synchrony of neural populations during periods of ripple and theta instances. The coupling between PGO waves and ripples, classically associated with distinct sleep stages, supports the notion that a global coordination mechanism of hippocampal sleep dynamics by cholinergic pontine transients may promote systems and synaptic memory consolidation as well as synaptic homeostasis.
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Puentes-Mestril C, Roach J, Niethard N, Zochowski M, Aton SJ. How rhythms of the sleeping brain tune memory and synaptic plasticity. Sleep 2019; 42:zsz095. [PMID: 31100149 PMCID: PMC6612670 DOI: 10.1093/sleep/zsz095] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 03/14/2019] [Indexed: 11/14/2022] Open
Abstract
Decades of neurobehavioral research has linked sleep-associated rhythms in various brain areas to improvements in cognitive performance. However, it remains unclear what synaptic changes might underlie sleep-dependent declarative memory consolidation and procedural task improvement, and why these same changes appear not to occur across a similar interval of wake. Here we describe recent research on how one specific feature of sleep-network rhythms characteristic of rapid eye movement and non-rapid eye movement-could drive synaptic strengthening or weakening in specific brain circuits. We provide an overview of how these rhythms could affect synaptic plasticity individually and in concert. We also present an overarching hypothesis for how all network rhythms occurring across the sleeping brain could aid in encoding new information in neural circuits.
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Affiliation(s)
| | - James Roach
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI
| | - Niels Niethard
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tuebingen, Tuebingen, Germany
| | - Michal Zochowski
- Department of Physics, Biophysics Program, University of Michigan, Ann Arbor, MI
| | - Sara J Aton
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
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7
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Puentes-Mestril C, Aton SJ. Linking Network Activity to Synaptic Plasticity during Sleep: Hypotheses and Recent Data. Front Neural Circuits 2017; 11:61. [PMID: 28932187 PMCID: PMC5592216 DOI: 10.3389/fncir.2017.00061] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/23/2017] [Indexed: 12/22/2022] Open
Abstract
Research findings over the past two decades have supported a link between sleep states and synaptic plasticity. Numerous mechanistic hypotheses have been put forth to explain this relationship. For example, multiple studies have shown structural alterations to synapses (including changes in synaptic volume, spine density, and receptor composition) indicative of synaptic weakening after a period of sleep. Direct measures of neuronal activity and synaptic strength support the idea that a period of sleep can reduce synaptic strength. This has led to the synaptic homeostasis hypothesis (SHY), which asserts that during slow wave sleep, synapses are downscaled throughout the brain to counteract net strengthening of network synapses during waking experience (e.g., during learning). However, neither the cellular mechanisms mediating these synaptic changes, nor the sleep-dependent activity changes driving those cellular events are well-defined. Here we discuss potential cellular and network dynamic mechanisms which could underlie reductions in synaptic strength during sleep. We also discuss recent findings demonstrating circuit-specific synaptic strengthening (rather than weakening) during sleep. Based on these data, we explore the hypothetical role of sleep-associated network activity patterns in driving synaptic strengthening. We propose an alternative to SHY—namely that depending on experience during prior wake, a variety of plasticity mechanisms may operate in the brain during sleep. We conclude that either synaptic strengthening or synaptic weakening can occur across sleep, depending on changes to specific neural circuits (such as gene expression and protein translation) induced by experiences in wake. Clarifying the mechanisms underlying these different forms of sleep-dependent plasticity will significantly advance our understanding of how sleep benefits various cognitive functions.
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Affiliation(s)
- Carlos Puentes-Mestril
- Neuroscience Graduate Program, Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, United States
| | - Sara J Aton
- Neuroscience Graduate Program, Department of Molecular, Cellular, and Developmental Biology, University of MichiganAnn Arbor, MI, United States
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8
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Reduced Theta Coherence and P Wave Ratio Linked to Memory Deficits After Sleep Deprivation in Rat Model. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s41782-017-0005-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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9
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Gilson M, Deliens G, Leproult R, Bodart A, Nonclercq A, Ercek R, Peigneux P. REM-Enriched Naps Are Associated with Memory Consolidation for Sad Stories and Enhance Mood-Related Reactivity. Brain Sci 2015; 6:brainsci6010001. [PMID: 26729175 PMCID: PMC4810171 DOI: 10.3390/brainsci6010001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 12/05/2015] [Accepted: 12/16/2015] [Indexed: 11/16/2022] Open
Abstract
Emerging evidence suggests that emotion and affect modulate the relation between sleep and cognition. In the present study, we investigated the role of rapid-eye movement (REM) sleep in mood regulation and memory consolidation for sad stories. In a counterbalanced design, participants (n = 24) listened to either a neutral or a sad story during two sessions, spaced one week apart. After listening to the story, half of the participants had a short (45 min) morning nap. The other half had a long (90 min) morning nap, richer in REM and N2 sleep. Story recall, mood evolution and changes in emotional response to the re-exposure to the story were assessed after the nap. Although recall performance was similar for sad and neutral stories irrespective of nap duration, sleep measures were correlated with recall performance in the sad story condition only. After the long nap, REM sleep density positively correlated with retrieval performance, while re-exposure to the sad story led to diminished mood and increased skin conductance levels. Our results suggest that REM sleep may not only be associated with the consolidation of intrinsically sad material, but also enhances mood reactivity, at least on the short term.
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Affiliation(s)
- Médhi Gilson
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
- UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), avenue F.D. Roosevelt 50, Bruxelles, Belgium.
| | - Gaétane Deliens
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
- UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), avenue F.D. Roosevelt 50, Bruxelles, Belgium.
- CO3-Consciousness, Cognition & Computation Group, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
| | - Rachel Leproult
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
- UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), avenue F.D. Roosevelt 50, Bruxelles, Belgium.
| | - Alice Bodart
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
- UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), avenue F.D. Roosevelt 50, Bruxelles, Belgium.
| | - Antoine Nonclercq
- LISA-Laboratories of Image, Signal processing and Acoustics, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
| | - Rudy Ercek
- LISA-Laboratories of Image, Signal processing and Acoustics, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
| | - Philippe Peigneux
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, avenue F.D. Roosevelt 50, Bruxelles 1050, Belgium.
- UNI-ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), avenue F.D. Roosevelt 50, Bruxelles, Belgium.
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10
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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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11
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Affiliation(s)
- Richard J Ross
- Behavioral Health Service, Philadelphia VA Medical Center, Philadelphia, PA, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA
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12
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Laitman BM, Gajewski ND, Mann GL, Kubin L, Morrison AR, Ross RJ. The α1 adrenoceptor antagonist prazosin enhances sleep continuity in fear-conditioned Wistar-Kyoto rats. Prog Neuropsychopharmacol Biol Psychiatry 2014; 49:7-15. [PMID: 24246572 PMCID: PMC3969852 DOI: 10.1016/j.pnpbp.2013.11.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 11/06/2013] [Accepted: 11/06/2013] [Indexed: 11/16/2022]
Abstract
Fragmentation of rapid eye movement sleep (REMS) is well described in individuals with posttraumatic stress disorder (PTSD) and likely has significant functional consequences. Fear-conditioned rodents may offer an attractive model of the changes in sleep that characterize PTSD. Following fear conditioning (FC), Wistar-Kyoto (WKY) rats, a strain known to be particularly stress-sensitive, have increased REMS fragmentation that can be quantified as a shift in the distribution of REMS episodes towards the more frequent occurrence of sequential REMS (inter-REMS episode interval≤3 min) vs. single REMS (interval>3 min). The α1 adrenoceptor antagonist prazosin has demonstrated efficacy in normalizing sleep in PTSD. To determine the utility of fear-conditioned WKY rats as a model of sleep disturbances typical of PTSD and as a platform for the development of new treatments, we tested the hypothesis that prazosin would reduce REMS fragmentation in fear-conditioned WKY rats. Sleep parameters and freezing (a standard measure of anxiety in rodents) were quantified at baseline and on Days 1, 7, and 14 following FC, with either prazosin (0.01mg/kg, i.p.) or vehicle injections administered prior to testing in a between-group design. Fear conditioning was achieved by pairing tones with a mild electric foot shock (1.0mA, 0.5s). One, 7, and 14 days following FC, prazosin or vehicle was injected, the tone was presented, freezing was measured, and then sleep was recorded from 11 AM to 3 PM. WKY rats given prazosin, compared to those given vehicle, had a lower amount of seq-REMS relative to total REMS time 14 days after FC. They also had a shorter non-REMS latency and fewer non-REMS arousals at baseline and on Days 1 and 7 after FC. Thus, in FC rats, prazosin reduced both REMS fragmentation and non-REMS discontinuity.
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Affiliation(s)
- Benjamin M. Laitman
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA,Address correspondence to: Benjamin M. Laitman, The Graduate School of Biological Sciences, Mount Sinai School of Medicine, 1 Gustave L. Levy Place, New York, NY 10029, Tel. 516 2368979, Fax. 215 8235171 (Attn: Dr. Richard Ross),
| | - Nicholas D. Gajewski
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Graziella L. Mann
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Leszek Kubin
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Adrian R. Morrison
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA
| | - Richard J. Ross
- Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA,Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA,Veterans Affairs Medical Center, Philadelphia, PA
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Grønli J, Soulé J, Bramham CR. Sleep and protein synthesis-dependent synaptic plasticity: impacts of sleep loss and stress. Front Behav Neurosci 2014; 7:224. [PMID: 24478645 PMCID: PMC3896837 DOI: 10.3389/fnbeh.2013.00224] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2013] [Accepted: 12/23/2013] [Indexed: 01/08/2023] Open
Abstract
Sleep has been ascribed a critical role in cognitive functioning. Several lines of evidence implicate sleep in the consolidation of synaptic plasticity and long-term memory. Stress disrupts sleep while impairing synaptic plasticity and cognitive performance. Here, we discuss evidence linking sleep to mechanisms of protein synthesis-dependent synaptic plasticity and synaptic scaling. We then consider how disruption of sleep by acute and chronic stress may impair these mechanisms and degrade sleep function.
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Affiliation(s)
- Janne Grønli
- Department of Biological and Medical Psychology, University of Bergen Bergen, Norway ; Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital Bergen, Norway
| | - Jonathan Soulé
- Department of Biological and Medical Psychology, University of Bergen Bergen, Norway
| | - Clive R Bramham
- Department of Biomedicine and KG Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen Bergen, Norway
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14
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Picchioni D, Duyn JH, Horovitz SG. Sleep and the functional connectome. Neuroimage 2013; 80:387-96. [PMID: 23707592 DOI: 10.1016/j.neuroimage.2013.05.067] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2013] [Revised: 05/10/2013] [Accepted: 05/13/2013] [Indexed: 02/02/2023] Open
Abstract
Sleep and the functional connectome are research areas with considerable overlap. Neuroimaging studies of sleep based on EEG-PET and EEG-fMRI are revealing the brain networks that support sleep, as well as networks that may support the roles and processes attributed to sleep. For example, phenomena such as arousal and consciousness are substantially modulated during sleep, and one would expect this modulation to be reflected in altered network activity. In addition, recent work suggests that sleep also has a number of adaptive functions that support waking activity. Thus the study of sleep may elucidate the circuits and processes that support waking function and complement information obtained from fMRI during waking conditions. In this review, we will discuss examples of this for memory, arousal, and consciousness after providing a brief background on sleep and on studying it with fMRI.
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Affiliation(s)
- Dante Picchioni
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD, USA
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15
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Caveats on psychological models of sleep and memory: A compass in an overgrown scenario. Sleep Med Rev 2013; 17:105-21. [DOI: 10.1016/j.smrv.2012.04.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2011] [Revised: 04/02/2012] [Accepted: 04/02/2012] [Indexed: 12/20/2022]
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16
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Abstract
Over more than a century of research has established the fact that sleep benefits the retention of memory. In this review we aim to comprehensively cover the field of "sleep and memory" research by providing a historical perspective on concepts and a discussion of more recent key findings. Whereas initial theories posed a passive role for sleep enhancing memories by protecting them from interfering stimuli, current theories highlight an active role for sleep in which memories undergo a process of system consolidation during sleep. Whereas older research concentrated on the role of rapid-eye-movement (REM) sleep, recent work has revealed the importance of slow-wave sleep (SWS) for memory consolidation and also enlightened some of the underlying electrophysiological, neurochemical, and genetic mechanisms, as well as developmental aspects in these processes. Specifically, newer findings characterize sleep as a brain state optimizing memory consolidation, in opposition to the waking brain being optimized for encoding of memories. Consolidation originates from reactivation of recently encoded neuronal memory representations, which occur during SWS and transform respective representations for integration into long-term memory. Ensuing REM sleep may stabilize transformed memories. While elaborated with respect to hippocampus-dependent memories, the concept of an active redistribution of memory representations from networks serving as temporary store into long-term stores might hold also for non-hippocampus-dependent memory, and even for nonneuronal, i.e., immunological memories, giving rise to the idea that the offline consolidation of memory during sleep represents a principle of long-term memory formation established in quite different physiological systems.
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Affiliation(s)
- Björn Rasch
- Division of Biopsychology, Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland.
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17
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Abstract
This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making.
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Affiliation(s)
- Ritchie E Brown
- Laboratory of Neuroscience, VA Boston Healthcare System and Harvard Medical School, Brockton, Massachusetts 02301, USA
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Kocsis B. State-dependent increase of cortical gamma activity during REM sleep after selective blockade of NR2B subunit containing NMDA receptors. Sleep 2012; 35:1011-6. [PMID: 22754048 DOI: 10.5665/sleep.1972] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Sub-anesthetic doses of NMDA receptor antagonists suppress sleep and elicit continuous high-power gamma oscillations lasting for hours. This effect is subunit-specific, as it was also seen after preferential blockade of the NR2A but not of the NR2B subunit-containing receptors. The objective of this study was to test whether NR2B receptor antagonists that do not induce lasting aberrant gamma elevation affect gamma activity during specific behaviors and states, including REM sleep, when gamma normally occurs. DESIGN Gamma oscillations in cortical EEG were assessed in different vigilance states in rats and were compared before and after injection of nonselective (ketamine, 10 mg/kg, and MK801, 0.2 mg/kg), as well as NR2A-preferring (NVP-AAM077, 20 mg/kg), and NR2B-selective NMDA receptor antagonists (Ro25-6985, 10 mg), and vehicle. MEASUREMENTS AND RESULTS In contrast to nonselective and NR2A-preferring antagonists, Ro25-6985 did not disrupt sleep and had no effect on gamma activity during waking and slow wave sleep. It significantly increased, however, gamma power in the frontal (but not in occipital) cortex during REM sleep (by 37% ± 10%, average in the first 4 h). The effect had a short onset; enhanced gamma activity appeared as early as in the first REM sleep episode post-injection and lasted over 8 hours. Increased gamma power induced by MK-801 (46% ± 5%) and NVP-AAM077 (100% ± 8%) during REM sleep could also be detected several hours after injection when periodic alternation of sleep-wake states returned. CONCLUSIONS By acting on gamma oscillations in a state-dependent manner, NMDA receptors might have subunit-specific role in REM sleep-associated cognitive processes.
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Affiliation(s)
- Bernat Kocsis
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Neuronal Oscillations in Sleep: Insights from Functional Neuroimaging. Neuromolecular Med 2012; 14:154-67. [DOI: 10.1007/s12017-012-8166-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Accepted: 01/06/2012] [Indexed: 12/31/2022]
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DaSilva JK, Husain E, Lei Y, Mann GL, Tejani-Butt S, Morrison AR. Social partnering significantly reduced rapid eye movement sleep fragmentation in fear-conditioned, stress-sensitive Wistar-Kyoto rats. Neuroscience 2011; 199:193-204. [PMID: 22015926 DOI: 10.1016/j.neuroscience.2011.09.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 09/30/2011] [Accepted: 09/30/2011] [Indexed: 10/16/2022]
Abstract
Negative emotionality affects sleep-wake behavior in humans and rodents, and the Wistar-Kyoto (WKY) rat strain is known for its stress-sensitive phenotype. Analyzing rapid eye movement sleep (REMS) microarchitecture by separating REMS into single (siREMS; inter-REM episode interval>3 min) and sequential (seqREMS; interval≤3 min) episodes, we previously reported that cued fear conditioning (CFC) increased REMS fragmentation in WKY compared to Wistar rats by increasing the number of seqREMS episodes. Since social support affects fear responsiveness in humans, we hypothesized that social interaction with a naive partner would affect the sleep-wake response to CFC in WKY rats. Thus, male WKY rats were assigned to either the social support or the social isolation group. Animals were fear-conditioned to 10 tones (800 Hz, 90 dB, 5 s), each co-terminating with a mild foot shock (1.0 mA, 0.5 s), at 30-s intervals. All subjects underwent a tone-only test both 24 h (Day 1) and again two weeks (Day 14) later. Social partnering was achieved by providing the fear-conditioned rat with 30 min of interaction with its naive partner immediately after CFC and during the tone presentations on Day 1 and Day 14. The results indicate that while CFC increased freezing behavior in socially isolated WKY rats, it increased grooming behavior in socially partnered rats. Socially partnered rats had increased sleep efficiency during the light phase and spent less time in NREMS during the dark phase. The number of siREMS episodes increased during both the light and dark phases in partnered rats, and the number of seqREMS episodes increased in socially isolated rats. Our findings suggest that social partnering may protect WKY rats from the REMS fragmentation that is observed following CFC in isolation.
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Affiliation(s)
- J K DaSilva
- Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 South 43rd Street, Philadelphia, PA 19104, USA.
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Walsh CM, Booth V, Poe GR. Spatial and reversal learning in the Morris water maze are largely resistant to six hours of REM sleep deprivation following training. Learn Mem 2011; 18:422-34. [PMID: 21677190 DOI: 10.1101/lm.2099011] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
This first test of the role of REM (rapid eye movement) sleep in reversal spatial learning is also the first attempt to replicate a much cited pair of papers reporting that REM sleep deprivation impairs the consolidation of initial spatial learning in the Morris water maze. We hypothesized that REM sleep deprivation following training would impair both hippocampus-dependent spatial learning and learning a new target location within a familiar environment: reversal learning. A 6-d protocol was divided into the initial spatial learning phase (3.5 d) immediately followed by the reversal phase (2.5 d). During the 6 h following four or 12 training trials/day of initial or reversal learning phases, REM sleep was eliminated and non-REM sleep left intact using the multiple inverted flowerpot method. Contrary to our hypotheses, REM sleep deprivation during four or 12 trials/day of initial spatial or reversal learning did not affect training performance. However, some probe trial measures indicated REM sleep-deprivation-associated impairment in initial spatial learning with four trials/day and enhancement of subsequent reversal learning. In naive animals, REM sleep deprivation during normal initial spatial learning was followed by a lack of preference for the subsequent reversal platform location during the probe. Our findings contradict reports that REM sleep is essential for spatial learning in the Morris water maze and newly reveal that short periods of REM sleep deprivation do not impair concurrent reversal learning. Effects on subsequent reversal learning are consistent with the idea that REM sleep serves the consolidation of incompletely learned items.
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Affiliation(s)
- Christine M Walsh
- Neuroscience Program, University of Michigan, Ann Arbor, MI 48109, USA
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22
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Affiliation(s)
- Carlyle Smith
- Department of Psychology, Trent University, Peterborough, Canada.
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23
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Laitman BM, Dasilva JK, Ross RJ, Tejani-Butt S, Morrison AR. Reduced γ range activity at REM sleep onset and termination in fear-conditioned Wistar-Kyoto rats. Neurosci Lett 2011; 493:14-7. [PMID: 21316420 DOI: 10.1016/j.neulet.2011.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 01/20/2011] [Accepted: 02/01/2011] [Indexed: 10/18/2022]
Abstract
Recent investigations of rapid eye movement sleep (REMS) continuity have emphasized the importance of transitions both into and out of REMS. We have previously reported that, compared to Wistar rats (WIS), Wistar-Kyoto rats (WKY) responded to fear conditioning (FC) with more fragmented REMS. Gamma oscillations in the electroencephalogram (EEG) are synchronized throughout the brain in periods of focused attention, and such synchronization of cell assemblies in the brain may represent a temporal binding mechanism. Therefore, we examined the effects of FC on EEG gamma range activity (30-50Hz) at REMS transitions in WKY compared to WIS. Relative power in the gamma range (measured as a percent of total power) at Baseline and upon re-exposure to the fear-inducing conditioning stimulus was measured 35s before REMS onset to 105s after REMS onset (ARO) and 85s before REMS termination (BRT) to 35s after REMS termination. After baseline recording, rats received 10 tones, each co-terminating with an electric foot shock. On Days 1 and 14 post-conditioning, rats were re-exposed to three tones. Fast-Fourier transforms created power spectral data in the gamma frequency domain. Relative power was extracted from an average of 4-5 REMS transitions. Relative gamma power was always higher in WIS. On Day 14, at 15s and 25s ARO, WKY had significant increases in relative gamma power from Baseline. WIS had a significant increase on Day 1 at 25s ARO. Despite the increases in relative gamma power, WKY never achieved levels attained by WIS. Moreover, at 5s BRT, only WKY had a significant decrease in relative gamma power from Baseline to Day 14. Gamma range activity may indicate neural activity underlying maintenance of REMS continuity. Low relative gamma power at REMS transitions may be associated with increased REMS fragmentation in WKY after FC.
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Affiliation(s)
- Benjamin M Laitman
- University of Pennsylvania School of Veterinary Medicine, Department of Animal Biology, 3800 Spruce Street, Philadelphia, PA 19104, USA.
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DaSilva JK, Lei Y, Madan V, Mann GL, Ross RJ, Tejani-Butt S, Morrison AR. Fear conditioning fragments REM sleep in stress-sensitive Wistar-Kyoto, but not Wistar, rats. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:67-73. [PMID: 20832443 PMCID: PMC3019280 DOI: 10.1016/j.pnpbp.2010.08.023] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 07/29/2010] [Accepted: 08/25/2010] [Indexed: 12/22/2022]
Abstract
Pavlovian conditioning is commonly used to investigate the mechanisms of fear learning. Because the Wistar-Kyoto (WKY) rat strain is particularly stress-sensitive, we investigated the effects of a psychological stressor on sleep in WKY compared to Wistar (WIS) rats. Male WKY and WIS rats were either fear-conditioned to tone cues or received electric foot shocks alone. In the fear-conditioning procedure, animals were exposed to 10 tones (800 Hz, 90 dB, 5s), each co-terminating with a foot shock (1.0 mA, 0.5s), at 30-s intervals. In the shock stress procedure, animals received 10 foot shocks at 30-s intervals, without tones. All subjects underwent a tone-only test both 24h (Day 1) and again two weeks (Day 14) later. Rapid eye movement sleep (REMS) continuity was investigated by partitioning REMS episodes into single (inter-REMS episode interval >3 min) and sequential (interval ≤ 3 min) episodes. In the fear-conditioned group, freezing increased from baseline in both strains, but the increase was maintained on Day 14 in WKY rats only. In fear-conditioned WKY rats, total REMS amount increased on Day 1, sequential REMS amount increased on Day 1 and Day 14, and single REMS amount decreased on Day 14. Alterations were due to changes in the number of sequential and single REMS episodes. Shock stress had no significant effect on REMS microarchitecture in either strain. The shift toward sequential REMS in fear-conditioned WKY rats may represent REMS fragmentation, and may provide a model for investigating the neurobiological mechanisms of sleep disturbances reported in posttraumatic stress disorder.
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Affiliation(s)
- Jamie K. DaSilva
- University of the Sciences in Philadelphia, Department of Pharmaceutical Sciences (Box 80), 600 South 43rd Street, Philadelphia, PA 19104, USA,Corresponding Author: Jamie K. DaSilva, Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 South 43rd Street, Philadelphia, PA 19104,
| | - Yanlin Lei
- University of the Sciences in Philadelphia, Department of Pharmaceutical Sciences (Box 80), 600 South 43rd Street, Philadelphia, PA 19104, USA
| | - Vibha Madan
- University of Pennsylvania School of Veterinary Medicine, Department of Animal Biology, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Graziella L. Mann
- University of Pennsylvania School of Veterinary Medicine, Department of Animal Biology, 3800 Spruce Street, Philadelphia, PA 19104, USA
| | - Richard J. Ross
- University of Pennsylvania School of Veterinary Medicine, Department of Animal Biology, 3800 Spruce Street, Philadelphia, PA 19104, USA,Philadelphia Veterans Affairs Medical Center, Behavioral Health Service, 3900 Woodland Avenue, Philadelphia, PA 19104, USA,University of Pennsylvania School of Medicine, Department of Psychiatry, 423 Guardian Drive, Philadelphia, PA 19104, USA
| | - Shanaz Tejani-Butt
- University of the Sciences in Philadelphia, Department of Pharmaceutical Sciences (Box 80), 600 South 43rd Street, Philadelphia, PA 19104, USA
| | - Adrian R. Morrison
- University of Pennsylvania School of Veterinary Medicine, Department of Animal Biology, 3800 Spruce Street, Philadelphia, PA 19104, USA
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26
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Dang-Vu TT, Schabus M, Desseilles M, Sterpenich V, Bonjean M, Maquet P. Functional neuroimaging insights into the physiology of human sleep. Sleep 2010; 33:1589-603. [PMID: 21120121 PMCID: PMC2982729 DOI: 10.1093/sleep/33.12.1589] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Functional brain imaging has been used in humans to noninvasively investigate the neural mechanisms underlying the generation of sleep stages. On the one hand, REM sleep has been associated with the activation of the pons, thalamus, limbic areas, and temporo-occipital cortices, and the deactivation of prefrontal areas, in line with theories of REM sleep generation and dreaming properties. On the other hand, during non-REM (NREM) sleep, decreases in brain activity have been consistently found in the brainstem, thalamus, and in several cortical areas including the medial prefrontal cortex (MPFC), in agreement with a homeostatic need for brain energy recovery. Benefiting from a better temporal resolution, more recent studies have characterized the brain activations related to phasic events within specific sleep stages. In particular, they have demonstrated that NREM sleep oscillations (spindles and slow waves) are indeed associated with increases in brain activity in specific subcortical and cortical areas involved in the generation or modulation of these waves. These data highlight that, even during NREM sleep, brain activity is increased, yet regionally specific and transient. Besides refining the understanding of sleep mechanisms, functional brain imaging has also advanced the description of the functional properties of sleep. For instance, it has been shown that the sleeping brain is still able to process external information and even detect the pertinence of its content. The relationship between sleep and memory has also been refined using neuroimaging, demonstrating post-learning reactivation during sleep, as well as the reorganization of memory representation on the systems level, sometimes with long-lasting effects on subsequent memory performance. Further imaging studies should focus on clarifying the role of specific sleep patterns for the processing of external stimuli, as well as the consolidation of freshly encoded information during sleep.
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Affiliation(s)
- Thien Thanh Dang-Vu
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neurology, Liege University Hospital, Liege, Belgium
| | - Manuel Schabus
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Martin Desseilles
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neuroscience, University of Geneva, Geneva, Switzerland
| | | | - Maxime Bonjean
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Howard Hughes Medical Institute, The Salk Institute & School of Medicine, University of California, San Diego, CA
| | - Pierre Maquet
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neurology, Liege University Hospital, Liege, Belgium
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27
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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.
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Affiliation(s)
- Gina R Poe
- Departments of Anesthesiology and Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA.
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28
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Heister DS, Hayar A, Garcia-Rill E. Cholinergic modulation of GABAergic and glutamatergic transmission in the dorsal subcoeruleus: mechanisms for REM sleep control. Sleep 2009; 32:1135-47. [PMID: 19750918 PMCID: PMC2737571 DOI: 10.1093/sleep/32.9.1135] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVES Dorsal subcoeruleus (SubCD) neurons are thought to promote PGO waves and to be modulated by cholinergic afferents during REM sleep. We examined the differential effect of the cholinergic agonist carbachol (CAR) on excitatory and inhibitory postsynaptic currents (PSCs), and investigated the effects of CAR on SubCD neurons during the developmental decrease in REM sleep. DESIGN Whole-cell patch clamp recordings were conducted on brainstem slices of 7- to 20-day-old rats. MEASUREMENTS AND RESULTS CAR acted directly on 50% of SubCD neurons by inducing an inward current, via both nicotinic and muscarinic M1 receptors. CAR induced a potassium mediated outward current via activation of M2 muscarinic receptors in 43% of SubCD cells. Evoked stimulation established the presence of NMDA, AMPA, GABA, and glycinergic PSCs in the SubCD. CAR was found to decrease the amplitude of evoked EPSCs in 31 of 34 SubCD cells, but decreased the amplitude of evoked IPSCs in only 1 of 13 SubCD cells tested. Spontaneous EPSCs were decreased by CAR in 55% of cells recorded, while spontaneous IPSCs were increased in 27% of SubCD cells. These findings indicate that CAR exerts a predominantly inhibitory role on fast synaptic glutamatergic activity and a predominantly excitatory role on fast synaptic GABAergic/glycinergic activity in the SubCD. CONCLUSION We hypothesize that during REM sleep, cholinergic "REM-on" neurons that project to the SubCD induce an excitation of inhibitory interneurons and inhibition of excitatory events leading to the production of coordinated activity in SubCD projection neurons. The coordination of these projection neurons may be essential for the production of REM sleep signs such as PGO waves.
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Affiliation(s)
- David S. Heister
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Abdallah Hayar
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR
| | - Edgar Garcia-Rill
- Center for Translational Neuroscience, Department of Neurobiology and Developmental Sciences, University of Arkansas for Medical Sciences, Little Rock, AR
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29
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Abstract
The idea that sleep might be involved in brain plasticity has been investigated for many years through a large number of animal and human studies, but evidence remains fragmentary. Large amounts of sleep in early life suggest that sleep may play a role in brain maturation. In particular, the influence of sleep in developing the visual system has been highlighted. The current data suggest that both Rapid Eye Movement (REM) and non-REM sleep states would be important for brain development. Such findings stress the need for optimal paediatric sleep management. In the adult brain, the role of sleep in learning and memory is emphasized by studies at behavioural, systems, cellular and molecular levels. First, sleep amounts are reported to increase following a learning task and sleep deprivation impairs task acquisition and consolidation. At the systems level, neurophysiological studies suggest possible mechanisms for the consolidation of memory traces. These imply both thalamocortical and hippocampo-neocortical networks. Similarly, neuroimaging techniques demonstrated the experience-dependent changes in cerebral activity during sleep. Finally, recent works show the modulation during sleep of cerebral protein synthesis and expression of genes involved in neuronal plasticity.
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Affiliation(s)
- T T Dang-Vu
- Cyclotron Research Centre, University of Liege, Belgium.
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30
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Datta S, Siwek DF, Stack EC. Identification of cholinergic and non-cholinergic neurons in the pons expressing phosphorylated cyclic adenosine monophosphate response element-binding protein as a function of rapid eye movement sleep. Neuroscience 2009; 163:397-414. [PMID: 19540313 DOI: 10.1016/j.neuroscience.2009.06.035] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 06/11/2009] [Accepted: 06/12/2009] [Indexed: 10/20/2022]
Abstract
Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of rapid eye movement (REM) sleep. In the present study performed on rats, phosphorylated cyclic AMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high rapid eye movement sleep (HR, approximately 27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With HR, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low rapid eye movement sleep (LR, approximately 2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr=0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr=0.88), PnO (Rsqr=0.87), and SubCD (Rsqr=0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr=0.70) and DRN (Rsqr=0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are inactive. More importantly, the regression analysis indicated that pCREB activation in approximately 98% of PPT cholinergic neurons, was caused by REM sleep. Moreover the results indicate that during REM sleep, PPT intracellular PKA activation and a transcriptional cascade involving pCREB occur exclusively in the cholinergic neurons.
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Affiliation(s)
- S Datta
- Laboratory of Sleep and Cognitive Neuroscience, Boston University School of Medicine, 85 East Newton Street, Suite M-902, Boston, MA 02118, USA.
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31
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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.
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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
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32
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Friess E, Schmid D, Modell S, Brunner H, Lauer CJ, Holsboer F, Ising M. Dex/CRH-test response and sleep in depressed patients and healthy controls with and without vulnerability for affective disorders. J Psychiatr Res 2008; 42:1154-62. [PMID: 18281062 DOI: 10.1016/j.jpsychires.2008.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 12/01/2007] [Accepted: 01/04/2008] [Indexed: 11/29/2022]
Abstract
Sleep electroencephalographic (EEG) abnormalities and increased hypothalamo-pituitary-adrenal (HPA) axis activity are the most prominent neurobiological findings in depression and were suggested as potential biomarker for depression. In particular, increased rapid eye movement sleep (REM) density, deficit in slow wave sleep and excessive stress hormone response are associated with an unfavorable long-term outcome of depression. Recent studies indicate that the sleep and endocrine parameters are related to each other. This study investigated the association of sleep structure including a quantitative EEG analysis with the results of the combined dexamethasone (Dex)/corticotropin-releasing hormone (CRH)-test in 14 patients with a severe major depression, 21 healthy probands with a positive family history of depression (HRPs) and 12 healthy control subjects without personal and family history for psychiatric disorders. As expected patients with depression showed an overactivity of the HPA axis, disturbed sleep continuity and prolonged latency until slow wave sleep in the first sleep cycle. Differences in microarchitecture of sleep were less prominent and restricted to a higher NonREM sigma power in the HRP group. Dexamethasone suppressed cortisol levels were positively associated with higher NonREM sigma power after merging the three groups. We also observed an inverse association between the ACTH response to the Dex/CRH-test and rapid eye movement sleep (REM) density in HRPs, with suggestive evidence also in patients, but not in controls. This contra-intuitive finding might be a result of the subject selection (unaffected HRPs, severely depressed patients) and the complementarity of the two markers. HRPs and patients with high disease vulnerability, indicated by an elevated REM density, seem to have a lower threshold until an actual disease process affecting the HPA axis translates into depression, and vice versa. To summarize, our findings provide further evidence that the HPA axis is involved in the sleep regulation in depression. These associations, however, are not unidimensional, but dependent on the kind of sleep parameters as well as on the selection of the subjects.
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Affiliation(s)
- Elisabeth Friess
- Max Planck Institute of Psychiatry, Kraepelinstr 10, 80804 Munich, Germany.
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33
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Lonart G, Tang X, Simsek-Duran F, Machida M, Sanford LD. The role of active zone protein Rab3 interacting molecule 1 alpha in the regulation of norepinephrine release, response to novelty, and sleep. Neuroscience 2008; 154:821-31. [PMID: 18495360 DOI: 10.1016/j.neuroscience.2008.03.047] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2008] [Revised: 03/15/2008] [Accepted: 03/18/2008] [Indexed: 11/15/2022]
Abstract
Sleep mechanisms and synaptic plasticity are thought to interact to regulate homeostasis and memory formation. However, the influences of molecules that mediate synaptic plasticity on sleep are not well understood. In this study we demonstrate that mice lacking Rab3 interacting molecule 1 alpha (RIM1 alpha) (Rim1 alpha KO), a protein of the synaptic active zone required for certain types of synaptic plasticity and learning, had 53+/-5% less baseline rapid eye movement (REM) sleep compared with their wild type littermates. Also, compared with wild type littermates, exposure of the mice to an open field or to a novel object induced more robust and longer lasting locomotion suggesting altered habituation. This difference in exploratory behavior correlated with genotype specific changes in REM and deregulated release of norepinephrine in the cortex and basal amygdala of the Rim1 alpha KO mice. Also, moderate sleep deprivation (4 h), a test of the homeostatic sleep response, induced REM sleep rebound with different time course in Rim1 alpha KO and their wild type littermates. As norepinephrine plays an important role in regulating arousal and REM sleep, our data suggest that noradrenergic deficiency in Rim1 alpha KO animals impacts exploratory behavior and sleep regulation and contributes to impairments in learning.
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Affiliation(s)
- G Lonart
- Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
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Datta S, Li G, Auerbach S. Activation of phasic pontine-wave generator in the rat: a mechanism for expression of plasticity-related genes and proteins in the dorsal hippocampus and amygdala. Eur J Neurosci 2008; 27:1876-92. [PMID: 18371081 DOI: 10.1111/j.1460-9568.2008.06166.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A number of behavioral studies have emphasized the importance of interactions between the pontine-wave (P-wave) generator and the dorsal hippocampus (DH) in two-way active avoidance (TWAA) memory processing; however, the direct involvement of the P-wave generator in the TWAA training trial-induced molecular events in the DH and amygdala has not been systematically evaluated. Here we demonstrate that the TWAA learning training trials activate P-wave generator, and increase phosphorylation of CREB (pCREB) and expression of activity-regulated cytoskeletal-associated (Arc) protein, as well as messenger ribonucleic acid (mRNAs) of Arc, brain-derived nerve growth factor (BDNF) and early growth response-1 (Egr-1) in the DH and amygdala. Selective elimination of P-wave-generating cells abolished P-wave activity and suppressed TWAA learning training trial-induced expression of pCREB and Arc proteins and Arc, BDNF and Egr-1 mRNAs in the DH and amygdala. Following a session of TWAA training, all rats were equal in terms of time spent in wakefulness, slow-wave sleep and rapid eye movement (REM) sleep irrespective of P-wave lesions. The second set of experiments demonstrated that localized cholinergic stimulation of the P-wave generator increased expression of Arc, BDNF and Egr-1 mRNAs in the DH. Together, these findings provide the first direct evidence that activation of P-wave-generating cells is critically involved in the TWAA training trial-induced expression of plasticity-related genes in the DH and amygdala. These findings are discussed in relation to the role of P-wave generator activation for the REM sleep-dependent development and cognitive functions of the brain.
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Affiliation(s)
- Subimal Datta
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, 715 Albany Street, Boston, MA 02118, USA.
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Peters KR, Smith V, Smith CT. Changes in Sleep Architecture following Motor Learning Depend on Initial Skill Level. J Cogn Neurosci 2007; 19:817-29. [PMID: 17488206 DOI: 10.1162/jocn.2007.19.5.817] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractPrevious research has linked both rapid eyemovement (REM) sleep and Stage 2 sleep to procedural memory consolidation. The present study sought to clarify the relationship between sleep stages and procedural memory consolidation by examining the effect of initial skill level in this relationship in young adults. In-home sleep recordings were performed on participants before and after learning the pursuit rotor task. We divided the participants into low- and high-skill groups based on their initial performance of the pursuit rotor task. In high-skill participants, there was a significant increase in Stage 2 spindle density after learning, and there was a significant correlation between the spindle density that occurred after learning and pursuit rotor performance at retest 1 week later. In contrast, there was a significant correlation between changes in REM density and performance on the pursuit rotor task during retest 1 week later in low-skill participants, although the actual increase in REM density failed to reach significance in this group. The results of the present study suggest the presence of a double dissociation in the sleep-related processes that are involved in procedural memory consolidation in low- and high-skill individuals. These results indicate that the changes in sleep microarchitecture that take place after learning depend on the initial skill level of the individual and therefore provide validation for the model proposed by Smith et al. [Smith, C. T., Aubrey, J. B., & Peters, K. R. Different roles for REM and Stage 2 sleep in motor learning. Psychologica Belgica, 44, 79–102, 2004]. Accordingly, skill level is an important variable that needs to be considered in future research on sleep and memory consolidation.
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Brown RE, Winston S, Basheer R, Thakkar MM, McCarley RW. Electrophysiological characterization of neurons in the dorsolateral pontine rapid-eye-movement sleep induction zone of the rat: Intrinsic membrane properties and responses to carbachol and orexins. Neuroscience 2006; 143:739-55. [PMID: 17008019 PMCID: PMC1775037 DOI: 10.1016/j.neuroscience.2006.08.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Revised: 08/11/2006] [Accepted: 08/16/2006] [Indexed: 11/20/2022]
Abstract
Pharmacological, lesion and single-unit recording techniques in several animal species have identified a region of the pontine reticular formation (subcoeruleus, SubC) just ventral to the locus coeruleus as critically involved in the generation of rapid-eye-movement (REM) sleep. However, the intrinsic membrane properties and responses of SubC neurons to neurotransmitters important in REM sleep control, such as acetylcholine and orexins/hypocretins, have not previously been examined in any animal species and thus were targeted in this study. We obtained whole-cell patch-clamp recordings from visually identified SubC neurons in rat brain slices in vitro. Two groups of large neurons (mean diameter 30 and 27 mum) were tentatively identified as cholinergic (rostral SubC) and noradrenergic (caudal SubC) neurons. SubC reticular neurons (non-cholinergic, non-noradrenergic) showed a medium-sized depolarizing sag during hyperpolarizing current pulses and often had a rebound depolarization (low-threshold spike, LTS). During depolarizing current pulses they exhibited little adaptation and fired maximally at 30-90 Hz. Those SubC reticular neurons excited by carbachol (n=27) fired spontaneously at 6 Hz, often exhibited a moderately sized LTS, and varied widely in size (17-42 mum). Carbachol-inhibited SubC reticular neurons were medium-sized (15-25 mum) and constituted two groups. The larger group (n=22) was silent at rest and possessed a prominent LTS and associated one to four action potentials. The second, smaller group (n=8) had a delayed return to baseline at the offset of hyperpolarizing pulses. Orexins excited both carbachol excited and carbachol inhibited SubC reticular neurons. SubC reticular neurons had intrinsic membrane properties and responses to carbachol similar to those described for other reticular neurons but a larger number of carbachol inhibited neurons were found (>50%), the majority of which demonstrated a prominent LTS and may correspond to pontine-geniculate-occipital burst neurons. Some or all carbachol-excited neurons are presumably REM-on neurons.
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Affiliation(s)
- R E Brown
- In Vitro Neurophysiology Section, Laboratory of Neuroscience, Department of Psychiatry, Harvard Medical School, VA Medical Center Brockton, Research 151C, 940, Belmont Street, Brockton, MA 02301, USA.
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Guzman-Marin R, Ying Z, Suntsova N, Methippara M, Bashir T, Szymusiak R, Gomez-Pinilla F, McGinty D. Suppression of hippocampal plasticity-related gene expression by sleep deprivation in rats. J Physiol 2006; 575:807-19. [PMID: 16825295 PMCID: PMC1995680 DOI: 10.1113/jphysiol.2006.115287] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Previous work shows that sleep deprivation impairs hippocampal-dependent learning and long-term potentiation (LTP). Brain-derived neurotrophic factor (BDNF), cAMP response-element-binding (CREB) and calcium-calmodulin-dependent protein kinase II (CAMKII) are critical modulators of hippocampal-dependent learning and LTP. In the present study we compared the effects of short- (8 h) and intermediate-term (48 h) sleep deprivation (SD) on the expression of BDNF and its downstream targets, Synapsin I, CREB and CAMKII in the neocortex and the hippocampus. Rats were sleep deprived using an intermittent treadmill system which equated total movement in the SD and control treadmill animals (CT), but permitted sustained periods of rest in CT animals. Animals were divided into SD (treadmill schedule: 3 s on/12 s off) and two treadmill control groups, CT1 (15 min on/60 min off) and CT2 (30 min on/120 min off - permitting more sustained sleep). Real-time Taqman RT-PCR was used to measure changes in mRNA; BDNF protein levels were determined using ELISA. In the hippocampus, 8 h treatments reduced BDNF, Synapsin I, CREB and CAMKII gene expression in both SD and control groups. Following 48 h of experimental procedures, the expression of all these four molecular markers of plasticity was reduced in SD and CT1 groups compared to the CT2 and cage control groups. In the hippocampus, BDNF protein levels after 8 h and 48 h treatments paralleled the changes in mRNA. In neocortex, neither 8 h nor 48 h SD or control treatments had significant effects on BDNF, Synapsin I and CAMKII mRNA levels. Stepwise regression analysis suggested that loss of REM sleep underlies the effects of SD on hippocampal BDNF, Synapsin I and CREB mRNA levels, whereas loss of NREM sleep underlies the effects on CAMKII mRNA.
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Affiliation(s)
- Ruben Guzman-Marin
- Research Service (151A3), V. A. Greater Los Angeles Healthcare System, 16111 Plummer Street, North Hills CA 91343, USA
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George O, Vallée M, Le Moal M, Mayo W. Neurosteroids and cholinergic systems: implications for sleep and cognitive processes and potential role of age-related changes. Psychopharmacology (Berl) 2006; 186:402-13. [PMID: 16416333 DOI: 10.1007/s00213-005-0254-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2005] [Accepted: 10/07/2005] [Indexed: 01/04/2023]
Abstract
RATIONALE The neurosteroids pregnenolone sulfate (PREGS), dehydroepiandrosterone sulfate (DHEAS) and allopregnanolone (3alpha,5alpha THPROG) have been implicated as powerful modulators of memory processes and sleep states in young and aged subjects with memory impairment. As these processes depend on the integrity of cholinergic systems, a specific effect of neurosteroids on these systems may account for their effects on sleep and memory. OBJECTIVE To review the evidence for a specific and differential effect of neurosteroids on cholinergic systems. METHODS We carried out keyword searches in "Medline" to identify articles concerning (1) the effects of neurosteroids on cholinergic systems, sleep and memory processes, and (2) changes in neurosteroid concentrations during aging. Few results are available for humans. Most data concerned rodents. RESULTS Peripheral and central administrations of PREGS, DHEAS, and 3alpha,5alpha THPROG modulate the basal forebrain and brainstem projection cholinergic neurons but not striatal cholinergic interneurons. Local administration of neurosteroids to the basal forebrain and brainstem cholinergic neurons alters sleep and memory in rodents. There are a few conflicting reports concerning the effects of aging on neurosteroid concentrations in normal and pathological conditions. CONCLUSIONS The specific modulation of basal forebrain and brainstem cholinergic systems by neurosteroids may account for the effects of these compounds on sleep and memory processes. To improve our understanding of the role of neurosteroids in cholinergic systems during normal and pathological aging, we need to determine whether there is specific regionalization of neurosteroids, and we need to investigate the relationship between neurosteroid concentrations in cholinergic nuclei and age-related sleep and memory impairments.
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Affiliation(s)
- Olivier George
- INSERM, U588, Institut François Magendie, Université de Bordeaux II, F-33077, Bordeaux, France.
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DATTA S. Activation of phasic pontine-wave generator: A mechanism for sleep-dependent memory processing. Sleep Biol Rhythms 2006. [DOI: 10.1111/j.1479-8425.2006.00202.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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NAKAO M, KARASHIMA A, IWASAKI N, KATAYAMA N, YAMAMOTO M. Fluctuations and synchronizations of neural activities during sleep: Neural basis of possible sleep functions? Sleep Biol Rhythms 2006. [DOI: 10.1111/j.1479-8425.2006.00206.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Smad-dependent alterations of PPT cholinergic neurons as a pathophysiological mechanism of age-related sleep-dependent memory impairments. Neurobiol Aging 2005; 27:1848-58. [PMID: 16316709 DOI: 10.1016/j.neurobiolaging.2005.10.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Revised: 10/07/2005] [Accepted: 10/18/2005] [Indexed: 11/29/2022]
Abstract
In humans, memory impairments are highly prevalent in the aged population, but their functional and structural origins are still unknown. We hypothesized that circadian rhythm alterations may predict spatial memory impairment in aged rats. We demonstrate an association between sleep/wake circadian rhythm disturbances (non-REM sleep fragmentation) and spatial memory impairments in aged rats. We show by light and electron microscopy that these age-related disruptions in circadian rhythm and spatial memory are also associated with degeneration of cholinergic neurons of the pedunculopontine nucleus (PPT), a structure known to be involved in sleep and cognitive functions and which is altered during aging. Finally, we demonstrate that a trophic deregulation of the PPT occur in aged impaired rats, involving an over activation of the TGFbeta-Smad cascade, a signalling pathway involved in neurodegeneration. In conclusion these results provide a new pathophysiological mechanism for age-related sleep-dependent memory impairments opening the ground for the development of new therapeutic approaches of these pathologies.
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Ulloor J, Datta S. Spatio-temporal activation of cyclic AMP response element-binding protein, activity-regulated cytoskeletal-associated protein and brain-derived nerve growth factor: a mechanism for pontine-wave generator activation-dependent two-way active-avoidance memory processing in the rat. J Neurochem 2005; 95:418-28. [PMID: 16190868 DOI: 10.1111/j.1471-4159.2005.03378.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study explored possible physiological and molecular mechanisms of pontine-wave (P-wave) generator activation-dependent memory processing in the rat using a two-way active-avoidance learning paradigm. The results show that learning training increased rapid eye movement sleep and activated brainstem cells in the P-wave generator. During this period, there was a time-dependent increase in phosphorylation of cAMP response element-binding protein (CREB) in the dorsal hippocampus and amygdala and increased synthesis of activity-regulated cytoskeletal-associated protein (Arc) in the dorsal hippocampus, amygdala, frontal cortex and occipital cortex. Learning training also increased synthesis of brain-derived nerve growth factor (BDNF) in the occipital cortex, amygdala and dorsal hippocampus at different time intervals. During this time, the levels of nerve growth factor did not change. The results also show that the increase in rapid eye movement sleep P-wave density during the post-training 3-h recording session is positively correlated with the increased levels of phosphorylated CREB, BDNF and Arc in the dorsal hippocampus. These results suggest that memory processing of two-way active-avoidance learning may involve excitation of P-wave-generating cells in the brainstem and increased expression of phosphorylated CREB, Arc and BDNF in a time-dependent manner in the forebrain. These dynamic changes in cellular and molecular features provide considerable insight into the mechanisms of the P-wave generator activation-dependent memory consolidation process.
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Affiliation(s)
- Jagadish Ulloor
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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Datta S, Saha S, Prutzman SL, Mullins OJ, Mavanji V. Pontine-wave generator activation-dependent memory processing of avoidance learning involves the dorsal hippocampus in the rat. J Neurosci Res 2005; 80:727-37. [PMID: 15880522 PMCID: PMC1224707 DOI: 10.1002/jnr.20501] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The aim of this study was to test the hypothesis that the dorsal hippocampus plays a critical role in pontine-wave (P-wave) generator activation-dependent memory processing of two-way active avoidance (TWAA) learning. To achieve this objective, rats were given small bilateral lesions in the CA1, dentate gyrus (DG), or CA3 region of the dorsal hippocampus by microinjecting ibotenic acid. After recovery, lesioned and sham-lesioned rats were trained on a TWAA learning paradigm, allowed a 6-hr period of undisturbed sleep, and then were tested on the same TWAA paradigm. It was found that lesions in the CA3 region impaired retention of avoidance learning. Conversely, lesions in the CA1 and DG regions had no effect on TWAA learning retention. None of the groups showed any changes in the baseline sleep-wake cycle or in the acquisition of TWAA learning. All rats showed increased rapid eye movement (REM) sleep and increased REM sleep P-wave density during the subsequent 6-hr recording period. Impaired retention in the CA3 group occurred despite an increase in REM sleep and P-wave density, suggesting that during REM sleep, the P-wave generator interacts with the CA3 region of the dorsal hippocampus to aid in consolidation of TWAA learning. The results of the present study thus demonstrate that P-wave generator activation-dependent consolidation of memory requires an intact CA3 subfield of the dorsal hippocampus. The results also provide evidence that under mnemonic pressure, the dorsal hippocampus may not be involved directly in regulating the sleep-wake cycle.
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Affiliation(s)
- Subimal Datta
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry and Program in Behavioral Neuroscience, Boston University School of Medicine, Boston, MA 02118, USA.
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Karashima A, Nakao M, Katayama N, Honda K. Instantaneous acceleration and amplification of hippocampal theta wave coincident with phasic pontine activities during REM sleep. Brain Res 2005; 1051:50-6. [PMID: 15982642 DOI: 10.1016/j.brainres.2005.05.055] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 05/18/2005] [Accepted: 05/23/2005] [Indexed: 12/17/2022]
Abstract
Rapid eye movement (REM) sleep is characterized by hippocampal theta waves and phasic spike-like waves originating from the pons, termed ponto-geniculo-occipital (PGO) waves in cats and pontine (P) waves in rats. While the theta wave and PGO/P wave have been suggested to participate in higher-order brain functions, their generation mechanisms and roles in brain functions have been studied independently. Therefore, the present study investigated instantaneous aspects of the relationship between theta waves and PGO/P waves in both cats and rats. Theta wave was instantaneously accelerated several hundred milliseconds before the negative peak of the PGO/P wave in both animals, and was also amplified just before PGO/P wave occurrence. Considering the integrated knowledge provided by studies of both animals, these results suggest that PGO/P wave-related activities in the pons are delivered to the theta wave generator. The activations of the theta wave coincident with PGO/P wave might facilitate cooperative contribution to higher-order brain functions in REM sleep.
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Affiliation(s)
- Akihiro Karashima
- Laboratory of Biomodeling, Graduate School of Information Sciences, Tohoku University, Aza Aoba 6-3-09, Aramaki, Aoba-ku, Sendai 980-8579, Japan.
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Saha S, Datta S. Two-way active avoidance training-specific increases in phosphorylated cAMP response element-binding protein in the dorsal hippocampus, amygdala, and hypothalamus. Eur J Neurosci 2005; 21:3403-14. [PMID: 16026478 DOI: 10.1111/j.1460-9568.2005.04166.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies have demonstrated that the activation of pontine-wave (P-wave) generating cells in the brainstem during post-training rapid eye movement (REM) sleep is critical for the consolidation of memory for two-way active avoidance (TWAA) learning in the rat. Here, using immunocytochemistry, we investigated the spatio-temporal distribution of CREB phosphorylation within different parts of the dorsal hippocampus, amygdala, and hypothalamus following a session of TWAA training in the rat. We show that the TWAA training trials increased phosphorylation of CREB (p-CREB) in the dorsal hippocampus, amygdala, amygdalo-hippocampal junction (AHi), and hypothalamus. However, the time intervals leading to training-induced p-CREB activity were different for different regions of the brain. In the dorsal hippocampus, p-CREB activity was maximal at 90 min and this activity disappeared by 180 min. In the AHi, activity of the p-CREB peaked by 180 min and disappeared by 360 min. In the amygdala, the p-CREB activity peaked at 180 min and still remained higher than the control at the 360 min interval. In the hypothalamus, at 90 min p-CREB activity was present only in the ventromedial hypothalamus; however, by 180 min this p-CREB activity was also present in the dorsal hypothalamus, perifornical area, and lateral hypothalamus. By 360 min, p-CREB activity disappeared from the hypothalamus. This TWAA training trials-induced spatiotemporal characteristic of CREB phosphorylation, for the first time, suggests that REM sleep P-wave generator activation-dependent memory processing involves different parts of the dorsal hippocampus, amygdala, and hypothalamus.
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Affiliation(s)
- Subhash Saha
- Sleep and Cognitive Neuroscience Laboratory, Department of Psychiatry, and Program in Behavioural Neuroscience, Boston University School of Medicine, Building M-902, 715 Albany Street, Boston, MA 02118, USA
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Sanford LD, Yang L, Tang X, Ross RJ, Morrison AR. Tetrodotoxin inactivation of pontine regions: Influence on sleep–wake states. Brain Res 2005; 1044:42-50. [PMID: 15862788 DOI: 10.1016/j.brainres.2005.02.079] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 02/21/2005] [Accepted: 02/24/2005] [Indexed: 11/19/2022]
Abstract
Studies using various methodologies have implicated n. reticularis pontis oralis (RPO) and n. subcoeruleus (SubC) in the generation of rapid eye movement sleep (REM). In rats, electrolytic lesions in these regions may give rise to the phenomenon of REM without atonia (REM-A), in which the electrophysiological features of REM are normal except that atonia is absent and elaborate behaviors may be exhibited. However, electrolytic lesions damage both cell bodies and fibers of passage, and the neural reorganization and adaptation that can occur post-lesion can complicate interpretation. Tetrodotoxin (TTX) is a sodium channel blocker that temporarily inactivates both neurons and fibers of passage and thus may be functionally equivalent to an electrolytic lesion, but without allowing time for neural adaptation. In this study, we examined the influence of microinjections of TTX into RPO and SubC on sleep in freely behaving rats. Rats (90 day old male Sprague-Dawley) were implanted with electrodes for recording EEG and EMG. Guide cannulae were implanted aimed into RPO or SubC. Each animal received one unilateral microinjection (TTXUH: 5.0 ng/0.2 microl) and two bilateral microinjections (TTXBL: 2.5 ng/0.1 microl; TTXBH: 5.0 ng/0.2 microl) of TTX, and control microinjections of saline alone (SAL). The injections were made 2 h following lights on, and sleep was recorded for the subsequent 22 h. Sleep was scored from computerized records in 10 s epochs. Recordings from the 10-h light period and the 12-h dark period were examined separately. TTX inactivation of RPO could decrease REM and non-REM (NREM), whereas inactivation of SubC produced relatively more specific decreases in REM with smaller effects on NREM. The results complement studies that have implicated RPO and SubC in REM generation. REM-A was not observed, suggesting that REM-A is a complex phenomenon that requires time for reorganization of the nervous system after insult.
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Affiliation(s)
- Larry D Sanford
- Sleep Research Laboratory, Department of Pathology and Anatomy, Eastern Virginia Medical School, PO Box 1980, Norfolk, VA 23501, USA.
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Quattrochi JJ, Bazalakova M, Hobson JA. From synapse to gene product: prolonged expression of c-fos induced by a single microinjection of carbachol in the pontomesencephalic tegmentum. ACTA ACUST UNITED AC 2005; 136:164-76. [PMID: 15893601 PMCID: PMC1570022 DOI: 10.1016/j.molbrainres.2005.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2004] [Revised: 01/25/2005] [Accepted: 02/03/2005] [Indexed: 11/26/2022]
Abstract
It is not known how the brain modifies its regulatory systems in response to the application of a drug, especially over the long term of weeks and months. We have developed a model system approach to this question by manipulating cholinergic cell groups of the laterodorsal and pedunculopontine tegmental (LDT/PPT) nuclei in the pontomesencephalic tegmentum (PMT), which are known to be actively involved in the timing and quantity of rapid eye movement (REM) sleep. In a freely moving feline model, a single microinjection of the cholinergic agonist carbachol conjugated to a latex nanosphere delivery system into the caudolateral PMT elicits a long-term enhancement of one distinguishing phasic event of REM sleep, ponto-geniculo-occipital (PGO) waves, lasting 5 days but without any significant change in REM sleep or other behavioral state. Here, we test the hypothesis that cholinergic activation within the caudolateral PMT alters the postsynaptic excitability of the PGO network, stimulating the prolonged expression of c-fos that underlies this long-term PGO enhancement (LTPE) effect. Using quantitative Fos immunohistochemistry, we found that the number of Fos-immunoreactive (Fos-IR) neurons surrounding the caudolateral PMT injection site decreased sharply by postcarbachol day 03, while the number of Fos-IR neurons in the more rostral LDT/PPT increased >30-fold and remained at a high level following the course of LTPE. These results demonstrate a sustained c-fos expression in response to pharmacological stimulation of the brain and suggest that carbachol's acute effects induce LTPE via cholinergic receptors, with subsequent transsynaptic activation of the LDT/PPT maintaining the LTPE effect.
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Affiliation(s)
- James J Quattrochi
- Laboratory for Cellular and Molecular Neuroscience and Program in Neuroscience, Harvard Medical School, WAB 425/447B, 200 Longwood, Boston, MA 02115, USA.
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Radulovacki M, Pavlovic S, Saponjic J, Carley DW. Modulation of reflex and sleep related apnea by pedunculopontine tegmental and intertrigeminal neurons. Respir Physiol Neurobiol 2005; 143:293-306. [PMID: 15519562 DOI: 10.1016/j.resp.2004.02.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2004] [Indexed: 11/17/2022]
Abstract
We describe and summarize here our recent findings about the role in respiration of two pontine structures that are not classically included in the pontine respiratory group: the pedunculopontine tegmental nucleus (PPT) and the intertrigeminal region (ITR). We also discuss significant contributions of other workers in the field, especially, S. Datta [Cell. Mol. Neurobiol. 17: 341-365, 1997], R. Lydic and H. Baghdoyan [Sleep, 25: 617-622, 2002], and N. Chamberlin and C. Saper [J. Neurosci. 18: 6048-6056, 1998], who postulated a role for the ITR in modulating reflex apnea. In anesthetized and freely moving rats we have consistently documented that PPT and ITR have a role in respiration. Neurochemical manipulations of each area affected the brainstem respiratory pattern generator and respiratory pattern variability,observed as spontaneous disturbances during sleep or as induced reflex apnea. Although the exact central mechanisms of apnea cannot be determined from our studies to date, we postulate that reflex and sleep-related apneas in rats share some common brainstem pathways, which may include PPT and ITR.
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Affiliation(s)
- Miodrag Radulovacki
- Department of Pharmacology, University of Illinois at Chicago, M/C 868, 901 S. Wolcott Avenue, Chicago, IL 60612, USA
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Pollock MS, Mistlberger RE. Microinjection of neostigmine into the pontine reticular formation of the mouse: further evaluation of a proposed REM sleep enhancement technique. Brain Res 2005; 1031:253-67. [PMID: 15649451 DOI: 10.1016/j.brainres.2004.10.056] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/19/2004] [Indexed: 12/29/2022]
Abstract
Microinjections of cholinergic agonists into the pontine reticular formation (PRF) powerfully induce rapid eye movement sleep (REMS) in cats but have comparatively weaker effects in rats. Recently, the cholinomimetic neostigmine has been reported to strongly enhance REMS following microinjection into the PRF of the mouse. That study used behavioral assessments of locomotion in lieu of electrophysiological measures of muscle tone to identify REMS. We sought to confirm that the behavioral state induced in mice by PRF injections of neostigmine meets standard electroencephalogram (EEG) and electromyogram (EMG) criteria for defining REMS. Cortical EEG, nuchal muscle EMG, and PGO waves were recorded from male C57BL/6N mice with chronic indwelling cannulae for the delivery of neostigmine to the PRF. Recordings were made during midday following injections of neostigmine (8.8 mM, 50 nl), 2 h after lights on (LD 12:12). Neostigmine induced a behavioral state characterized by low amplitude, highly desynchronized cortical EEG with little theta, no PGO waves, and a sustained high muscle tone. Behavioral states meeting standard criteria for slow-wave sleep (SWS) and REMS were significantly suppressed compared to baseline recordings, and REMS onset was delayed by 3 h. Consistent with earlier reports, neostigmine did strongly suppress locomotor activity in open field tests and in the home cage. Due to the failure to meet criteria for defining REMS, we conclude that neostigmine microinjection into the PRF of the mouse induces an abnormal waking state rather than REMS.
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Affiliation(s)
- Michael S Pollock
- Department of Psychology, Simon Fraser University, 8888 University Drive, Burnaby, BC, Canada V5A 1S6.
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Romcy-Pereira R, Pavlides C. Distinct modulatory effects of sleep on the maintenance of hippocampal and medial prefrontal cortex LTP. Eur J Neurosci 2004; 20:3453-62. [PMID: 15610178 DOI: 10.1111/j.1460-9568.2004.03808.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Both human and animal studies support the idea that memory consolidation of waking experiences occurs during sleep. In experimental models, rapid-eye-movement (REM) sleep has been shown to be necessary for cortical synaptic plasticity and for the acquisition of spatial and nonspatial memory. Because the hippocampus and medial prefrontal cortex (mPFC) play distinct and important roles in memory processing, we sought to determine the role of sleep in the maintenance of long-term potentiation (LTP) in the dentate gyrus (DG) and mPFC of freely behaving rats. Animals were implanted with stimulating and recording electrodes, either in the medial perforant path and DG or CA1 and mPFC, for the recording of field potentials. Following baseline recordings, LTP was induced and the animals were assigned to three different groups: REM sleep-deprived (REMD), total sleep-deprived (TSD) and control which were allowed to sleep (SLEEP). The deprivation protocol lasted for 4 h and the recordings were made during the first hour and at 5, 24 and 48 h following LTP induction. Our results show that REMD impaired the maintenance of late-phase (48-h) LTP in the DG, whereas it enhanced it in the mPFC. Sleep, therefore, could have distinct effects on the consolidation of different forms of memory.
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