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Liu J, Niethard N, Lun Y, Dimitrov S, Ehrlich I, Born J, Hallschmid M. Slow-wave sleep drives sleep-dependent renormalization of synaptic AMPA receptor levels in the hypothalamus. PLoS Biol 2024; 22:e3002768. [PMID: 39163472 PMCID: PMC11364421 DOI: 10.1371/journal.pbio.3002768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 08/30/2024] [Accepted: 07/25/2024] [Indexed: 08/22/2024] Open
Abstract
According to the synaptic homeostasis hypothesis (SHY), sleep serves to renormalize synaptic connections that have been potentiated during the prior wake phase due to ongoing encoding of information. SHY focuses on glutamatergic synaptic strength and has been supported by numerous studies examining synaptic structure and function in neocortical and hippocampal networks. However, it is unknown whether synaptic down-regulation during sleep occurs in the hypothalamus, i.e., a pivotal center of homeostatic regulation of bodily functions including sleep itself. We show that sleep, in parallel with the synaptic down-regulation in neocortical networks, down-regulates the levels of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in the hypothalamus of rats. Most robust decreases after sleep were observed at both sites for AMPARs containing the GluA1 subunit. Comparing the effects of selective rapid eye movement (REM) sleep and total sleep deprivation, we moreover provide experimental evidence that slow-wave sleep (SWS) is the driving force of the down-regulation of AMPARs in hypothalamus and neocortex, with no additional contributions of REM sleep or the circadian rhythm. SWS-dependent synaptic down-regulation was not linked to EEG slow-wave activity. However, spindle density during SWS predicted relatively increased GluA1 subunit levels in hypothalamic synapses, which is consistent with the role of spindles in the consolidation of memory. Our findings identify SWS as the main driver of the renormalization of synaptic strength during sleep and suggest that SWS-dependent synaptic renormalization is also implicated in homeostatic control processes in the hypothalamus.
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Affiliation(s)
- Jianfeng Liu
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Niels Niethard
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Yu Lun
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Stoyan Dimitrov
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
| | - Ingrid Ehrlich
- Department of Neurobiology, Institute of Biomaterials and Biomolecular Systems, University of Stuttgart, Stuttgart, Germany
| | - Jan Born
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
- Center for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University Tübingen (IDM), Tübingen, Germany
- German Center for Mental Health (DZPG), Tübingen, Germany
| | - Manfred Hallschmid
- Institute of Medical Psychology and Behavioural Neurobiology, University of Tübingen, Tübingen, Germany
- German Center for Diabetes Research (DZD), Tübingen, Germany
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Center Munich at the University Tübingen (IDM), Tübingen, Germany
- German Center for Mental Health (DZPG), Tübingen, Germany
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Singh R, Sharma D, Kumar A, Singh C, Singh A. Understanding zebrafish sleep and wakefulness physiology as an experimental model for biomedical research. FISH PHYSIOLOGY AND BIOCHEMISTRY 2024; 50:827-842. [PMID: 38150068 DOI: 10.1007/s10695-023-01288-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 12/07/2023] [Indexed: 12/28/2023]
Abstract
Sleep is a globally observable fact, or period of reversible distracted rest, that can be distinguished from arousal by various behavioral criteria. Although the function of sleep is an evolutionarily conserved behavior, its mechanism is not yet clear. The zebrafish (Danio rerio) has become a valuable model for neurobehavioral studies such as studying learning, memory, anxiety, and depression. It is characterized by a sleep-like state and circadian rhythm, making it comparable to mammals. Zebrafish are a good model for behavioral studies because they share genetic similarities with humans. A number of neurotransmitters are involved in sleep and wakefulness. There is a binding between melatonin and the hypocretin system present in zebrafish. The full understanding of sleep and wakefulness physiology in zebrafish is still unclear among researchers. Therefore, to make a clear understanding of the sleep/wake cycle in zebrafish, this article covers the mechanism involved behind it, and the role of the neuromodulator system followed by the mechanism of the HPA axis.
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Affiliation(s)
- Rima Singh
- Department of Pharmacology, Delhi Pharmaceutical Sciences & Research University (DPSRU), New Delhi, 110017, India
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India
| | - Deepali Sharma
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India
| | - Anoop Kumar
- Department of Pharmacology, Delhi Pharmaceutical Sciences & Research University (DPSRU), New Delhi, 110017, India
| | - Charan Singh
- Department of Pharmaceutical Sciences, HNB Garhwal University (A Central University), Chauras Campus, Distt, Tehri Garhwal, Uttarakhand, 246174, India
| | - Arti Singh
- Department of Pharmacology, ISF College of Pharmacy, Moga-142001, Affiliated to IK Gujral Punjab Technical University, Jalandhar, Punjab, 144603, India.
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Functional roles of REM sleep. Neurosci Res 2022; 189:44-53. [PMID: 36572254 DOI: 10.1016/j.neures.2022.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 12/01/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
Rapid eye movement (REM) sleep is an enigmatic and intriguing sleep state. REM sleep differs from non-REM sleep by its characteristic brain activity and from wakefulness by a reduced anti-gravity muscle tone. In addition to these key traits, diverse physiological phenomena appear across the whole body during REM sleep. However, it remains unclear whether these phenomena are the causes or the consequences of REM sleep. Experimental approaches using humans and animal models have gradually revealed the functional roles of REM sleep. Extensive efforts have been made to interpret the characteristic brain activity in the context of memory functions. Numerous physical and psychological functions of REM sleep have also been proposed. Moreover, REM sleep has been implicated in aspects of brain development. Here, we review the variety of functional roles of REM sleep, mainly as revealed by animal models. In addition, we discuss controversies regarding the functional roles of REM sleep.
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Jiang H. Hypothalamic GABAergic neurocircuitry in the regulation of energy homeostasis and sleep/wake control. MEDICAL REVIEW (BERLIN, GERMANY) 2022; 2:531-540. [PMID: 37724165 PMCID: PMC10388747 DOI: 10.1515/mr-2022-0022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 08/10/2022] [Indexed: 09/20/2023]
Abstract
Gamma-aminobutyric acid (GABAergic) neuron, as one of important cell types in synaptic transmission, has been widely involved in central nervous system (CNS) regulation of organismal physiologies including cognition, emotion, arousal and reward. However, upon their distribution in various brain regions, effects of GABAergic neurons in the brain are very diverse. In current report, we will present an overview of the role of GABAergic mediated inhibitory neurocircuitry in the hypothalamus, underlying mechanism of feeding and sleep homeostasis as well as the characteristics of latest transcriptome profile in order to call attention to the GABAergic system as potentially a promising pharmaceutical intervention or a deep brain stimulation target in eating and sleep disorders.
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Affiliation(s)
- Hong Jiang
- Department of Neurobiology, School of Basic Medical Sciences, Neuroscience Research Institute, Peking University, Beijing, China
- Key Laboratory for Neuroscience, Ministry of Education/National Health Commission of China, Peking University, Beijing, China
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