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Zhang K, Zhu Y, Fenik P, Fleysh D, Ly C, Thomas SA, Veasey S. Norepinephrine Drives Sleep Fragmentation Activation of Asparagine Endopeptidase, Locus Ceruleus Degeneration, and Hippocampal Amyloid-β 42 Accumulation. J Neurosci 2024; 44:e1929232024. [PMID: 38830763 PMCID: PMC11236578 DOI: 10.1523/jneurosci.1929-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 03/20/2024] [Accepted: 04/11/2024] [Indexed: 06/05/2024] Open
Abstract
Chronic sleep disruption (CSD), from insufficient or fragmented sleep and is an important risk factor for Alzheimer's disease (AD). Underlying mechanisms are not understood. CSD in mice results in degeneration of locus ceruleus neurons (LCn) and CA1 hippocampal neurons and increases hippocampal amyloid-β42 (Aβ42), entorhinal cortex (EC) tau phosphorylation (p-tau), and glial reactivity. LCn injury is increasingly implicated in AD pathogenesis. CSD increases NE turnover in LCn, and LCn norepinephrine (NE) metabolism activates asparagine endopeptidase (AEP), an enzyme known to cleave amyloid precursor protein (APP) and tau into neurotoxic fragments. We hypothesized that CSD would activate LCn AEP in an NE-dependent manner to induce LCn and hippocampal injury. Here, we studied LCn, hippocampal, and EC responses to CSD in mice deficient in NE [dopamine β-hydroxylase (Dbh)-/-] and control male and female mice, using a model of chronic fragmentation of sleep (CFS). Sleep was equally fragmented in Dbh -/- and control male and female mice, yet only Dbh -/- mice conferred resistance to CFS loss of LCn, LCn p-tau, and LCn AEP upregulation and activation as evidenced by an increase in AEP-cleaved APP and tau fragments. Absence of NE also prevented a CFS increase in hippocampal AEP-APP and Aβ42 but did not prevent CFS-increased AEP-tau and p-tau in the EC. Collectively, this work demonstrates AEP activation by CFS, establishes key roles for NE in both CFS degeneration of LCn neurons and CFS promotion of forebrain Aβ accumulation, and, thereby, identifies a key molecular link between CSD and specific AD neural injuries.
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Affiliation(s)
- Kathy Zhang
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Yan Zhu
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Polina Fenik
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Dennis Fleysh
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Colin Ly
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Steven A Thomas
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Sigrid Veasey
- Departments of Medicine and Pharmacology, Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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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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Zamore Z, Veasey SC. Neural consequences of chronic sleep disruption. Trends Neurosci 2022; 45:678-691. [PMID: 35691776 PMCID: PMC9388586 DOI: 10.1016/j.tins.2022.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/09/2022] [Accepted: 05/20/2022] [Indexed: 12/25/2022]
Abstract
Recent studies in both humans and animal models call into question the completeness of recovery after chronic sleep disruption. Studies in humans have identified cognitive domains particularly vulnerable to delayed or incomplete recovery after chronic sleep disruption, including sustained vigilance and episodic memory. These findings, in turn, provide a focus for animal model studies to critically test the lasting impact of sleep loss on the brain. Here, we summarize the human response to sleep disruption and then discuss recent findings in animal models examining recovery responses in circuits pertinent to vigilance and memory. We then propose pathways of injury common to various forms of sleep disruption and consider the implications of this injury in aging and in neurodegenerative disorders.
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Affiliation(s)
- Zachary Zamore
- Chronobiology and Sleep Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Sigrid C Veasey
- Chronobiology and Sleep Institute, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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Nick H, Fenik P, Zhu Y, Veasey S. Hypocretin/orexin influences chronic sleep disruption injury in the hippocampus. Front Aging Neurosci 2022; 14:1025402. [PMID: 36275002 PMCID: PMC9582517 DOI: 10.3389/fnagi.2022.1025402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/20/2022] [Indexed: 01/13/2023] Open
Abstract
Chronic sleep disruption is a risk factor for Alzheimer's disease (AD), yet mechanisms by which sleep disturbances might promote or exacerbate AD are not understood. Short-term sleep loss acutely increases hippocampal amyloid β (Aβ) in wild type (WT) mice and long-term sleep loss increases amyloid plaque in AD transgenic mouse models. Both effects can be influenced by the wake-promoting neuropeptide, hypocretin (HCRT), but whether HCRT influences amyloid accumulation independent of sleep and wake timing modulation remains unclear. Here, we induced chronic fragmentation of sleep (CFS) in WT and HCRT-deficient mice to elicit similar arousal indices, sleep bout lengths and sleep bout numbers in both genotypes. We then examined the roles of HCRT in CFS-induced hippocampal Aβ accumulation and injury. CFS in WT mice resulted in increased Aβ42 in the hippocampus along with loss of cholinergic projections and loss of locus coeruleus neurons. Mice with HCRT deficiency conferred resistance to CFS Aβ42 accumulation and loss of cholinergic projections in the hippocampus yet evidenced similar CFS-induced loss of locus coeruleus neurons. Collectively, the findings demonstrate specific roles for orexin in sleep disruption hippocampal injury. Significance statement Chronic fragmentation of sleep (CFS) occurs in common conditions, including sleep apnea syndromes and chronic pain disorders, yet CFS can induce neural injury. Our results demonstrate that under conditions of sleep fragmentation, hypocretin/orexin is essential for the accumulation of amyloid-β and loss of cholinergic projections in the hippocampus observed in response to CFS yet does not influence locus coeruleus neuron response to CFS.
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Affiliation(s)
- Henry Nick
- Department of Medicine and the Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania Philadelphia, Philadelphia, PA, United States
| | - Polina Fenik
- Department of Medicine and the Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania Philadelphia, Philadelphia, PA, United States
| | - Yan Zhu
- Department of Medicine and the Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania Philadelphia, Philadelphia, PA, United States
| | - Sigrid Veasey
- Department of Medicine and the Chronobiology and Sleep Institute, Perelman School of Medicine, University of Pennsylvania Philadelphia, Philadelphia, PA, United States
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Restorative effects of curcumin on sleep-deprivation induced memory impairments and structural changes of the hippocampus in a rat model. Life Sci 2017; 189:63-70. [DOI: 10.1016/j.lfs.2017.09.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/06/2017] [Accepted: 09/16/2017] [Indexed: 12/19/2022]
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Datta S, Oliver MD. Cellular and Molecular Mechanisms of REM Sleep Homeostatic Drive: A Plausible Component for Behavioral Plasticity. Front Neural Circuits 2017; 11:63. [PMID: 28959190 PMCID: PMC5603703 DOI: 10.3389/fncir.2017.00063] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 08/29/2017] [Indexed: 01/09/2023] Open
Abstract
Homeostatic regulation of REM sleep drive, as measured by an increase in the number of REM sleep transitions, plays a key role in neuronal and behavioral plasticity (i.e., learning and memory). Deficits in REM sleep homeostatic drive (RSHD) are implicated in the development of many neuropsychiatric disorders. Yet, the cellular and molecular mechanisms underlying this RSHD remain to be incomplete. To further our understanding of this mechanism, the current study was performed on freely moving rats to test a hypothesis that a positive interaction between extracellular-signal-regulated kinase 1 and 2 (ERK1/2) activity and brain-derived neurotrophic factor (BDNF) signaling in the pedunculopontine tegmentum (PPT) is a causal factor for the development of RSHD. Behavioral results of this study demonstrated that a short period (<90 min) of selective REM sleep restriction (RSR) exhibited a strong RSHD. Molecular analyses revealed that this increased RSHD increased phosphorylation and activation of ERK1/2 and BDNF expression in the PPT. Additionally, pharmacological results demonstrated that the application of the ERK1/2 activation inhibitor U0126 into the PPT prevented RSHD and suppressed BDNF expression in the PPT. These results, for the first time, suggest that the positive interaction between ERK1/2 and BDNF in the PPT is a casual factor for the development of RSHD. These findings provide a novel direction in understanding how RSHD-associated specific molecular changes can facilitate neuronal plasticity and memory processing.
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Affiliation(s)
- Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
| | - Michael D Oliver
- Laboratory of Sleep and Cognitive Neuroscience, Graduate School of Medicine, Department of Anesthesiology, The University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, The University of TennesseeKnoxville, TN, United States
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Totty MS, Chesney LA, Geist PA, Datta S. Sleep-Dependent Oscillatory Synchronization: A Role in Fear Memory Consolidation. Front Neural Circuits 2017; 11:49. [PMID: 28729826 PMCID: PMC5498516 DOI: 10.3389/fncir.2017.00049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 06/21/2017] [Indexed: 12/02/2022] Open
Abstract
Sleep plays an important role in memory consolidation through the facilitation of neuronal plasticity; however, how sleep accomplishes this remains to be completely understood. It has previously been demonstrated that neural oscillations are an intrinsic mechanism by which the brain precisely controls neural ensembles. Inter-regional synchronization of these oscillations is also known to facilitate long-range communication and long-term potentiation (LTP). In the present study, we investigated how the characteristic rhythms found in local field potentials (LFPs) during non-REM and REM sleep play a role in emotional memory consolidation. Chronically implanted bipolar electrodes in the lateral amygdala (LA), dorsal and ventral hippocampus (DH, VH), and the infra-limbic (IL), and pre-limbic (PL) prefrontal cortex were used to record LFPs across sleep-wake activity following each day of a Pavlovian cued fear conditioning paradigm. This resulted in three principle findings: (1) theta rhythms during REM sleep are highly synchronized between regions; (2) the extent of inter-regional synchronization during REM and non-REM sleep is altered by FC and EX; (3) the mean phase difference of synchronization between the LA and VH during REM sleep predicts changes in freezing after cued fear extinction. These results both oppose a currently proposed model of sleep-dependent memory consolidation and provide a novel finding which suggests that the role of REM sleep theta rhythms in memory consolidation may rely more on the relative phase-shift between neural oscillations, rather than the extent of phase synchronization.
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Affiliation(s)
- Michael S Totty
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Logan A Chesney
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Phillip A Geist
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States
| | - Subimal Datta
- Laboratory of Sleep and Cognitive Neuroscience, Department of Anesthesiology, Graduate School of Medicine, University of TennesseeKnoxville, TN, United States.,Department of Psychology, College of Arts and Sciences, University of TennesseeKnoxville, TN, United States
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Barnes AK, Koul-Tiwari R, Garner JM, Geist PA, Datta S. Activation of brain-derived neurotrophic factor-tropomyosin receptor kinase B signaling in the pedunculopontine tegmental nucleus: a novel mechanism for the homeostatic regulation of rapid eye movement sleep. J Neurochem 2017; 141:111-123. [PMID: 28027399 PMCID: PMC5364057 DOI: 10.1111/jnc.13938] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/09/2016] [Accepted: 12/09/2016] [Indexed: 02/04/2023]
Abstract
Rapid eye movement (REM) sleep dysregulation is a symptom of many neuropsychiatric disorders, yet the mechanisms of REM sleep homeostatic regulation are not fully understood. We have shown that, after REM sleep deprivation, the pedunculopontine tegmental nucleus (PPT) plays a critical role in the generation of recovery REM sleep. In this study, we used multidisciplinary techniques to show a causal relationship between brain-derived neurotrophic factor (BDNF)-tropomyosin receptor kinase B (TrkB) signaling in the PPT and the development of REM sleep homeostatic drive. Rats were randomly assigned to conditions of unrestricted sleep or selective REM sleep deprivation (RSD) with PPT microinjections of vehicle control or a dose of a TrkB receptor inhibitor (2, 3, or 4 nmol K252a or 4 nmol ANA-12). On experimental days, rats received PPT microinjections and their sleep-wake physiological signals were recorded for 3 or 6 h, during which selective RSD was performed in the first 3 h. At the end of all 3 h recordings, rats were killed and the PPT was dissected out for BDNF quantification. Our results show that K252a and ANA-12 dose-dependently reduced the homeostatic responses to selective RSD. Specifically, TrkB receptor inhibition reduced REM sleep homeostatic drive and limited REM sleep rebound. There was also a dose-dependent suppression of PPT BDNF up-regulation, and regression analysis revealed a significant positive relationship between REM sleep homeostatic drive and the level of PPT BDNF expression. These data provide the first direct evidence that activation of BDNF-TrkB signaling in the PPT is a critical step for the development of REM sleep homeostatic drive.
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Affiliation(s)
- Abigail K Barnes
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Richa Koul-Tiwari
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Jennifer M Garner
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Phillip A Geist
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA
| | - Subimal Datta
- Department of Anesthesiology, Graduate School of Medicine, The University of Tennessee, Knoxville, Tennessee, USA.,Department of Psychology, College of Arts and Sciences, The University of Tennessee, Knoxville, Tennessee, USA.,Program in Comparative and Experimental Medicine, The University of Tennessee, Knoxville, Tennessee, USA
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Stern AL, Naidoo N. Wake-active neurons across aging and neurodegeneration: a potential role for sleep disturbances in promoting disease. SPRINGERPLUS 2015; 4:25. [PMID: 25635245 PMCID: PMC4306674 DOI: 10.1186/s40064-014-0777-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Accepted: 12/23/2014] [Indexed: 12/13/2022]
Abstract
Sleep/wake disturbance is a feature of almost all common age-related neurodegenerative diseases. Although the reason for this is unknown, it is likely that this inability to maintain sleep and wake states is in large part due to declines in the number and function of wake-active neurons, populations of cells that fire only during waking and are silent during sleep. Consistent with this, many of the brain regions that are most susceptible to neurodegeneration are those that are necessary for wake maintenance and alertness. In the present review, these wake-active populations are systematically assessed in terms of their observed pathology across aging and several neurodegenerative diseases, with implications for future research relating sleep and wake disturbances to aging and age-related neurodegeneration.
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Affiliation(s)
- Anna L Stern
- Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Nirinjini Naidoo
- Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
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Wang W, Bai W, Cui G, Jin B, Wang K, Jia J, Da Y, Qin L. Effects of estradiol valerate and remifemin on norepinephrine signaling in the brain of ovariectomized rats. Neuroendocrinology 2015; 101:120-32. [PMID: 25613345 DOI: 10.1159/000375162] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/12/2015] [Indexed: 11/19/2022]
Abstract
AIMS We investigated the norepinephrine pathway changes from the locus coeruleus (LC) to the preoptic area of the hypothalamus (POAH) in the brain of ovariectomized rats under low estrogen levels and explored the therapeutic effects of estradiol valerate (E2) and Remifemin (ICR) on these changes. METHODS 40 female Sprague-Dawley rats were randomly divided into the following groups: surgery with vehicle (SHAM), ovariectomy surgery with vehicle (OVX), ovariectomy with E2 treatment (OVX + E2), and ovariectomy with Remifemin (OVX + ICR). After 4 weeks of treatment, we observed the changes by immunohistochemistry. RESULTS (1) The average optical density of DBH-ir fibers and the number of α1-adrenoreceptor- and estrogen receptor (ER)α-positive neurons in the main nuclei of POAH were all reduced in OVX rats compared with the SHAM group. The above changes were normalized in all nuclei of the POAH in the E2 group, while they were normalized in some nuclei in the ICR group. Coexpression of ERα and α1-adrenoreceptor was observed in the POAH. (2) The number of DBH- and ERα-positive neurons in the LC decreased in the OVX group compared with the SHAM group and increased after treatment with E2 and ICR. Coexpression of ERα and DBH was observed in the LC. CONCLUSION Low estrogen (OVX) altered norepinephrine synthesis in the LC, the projection of norepinephrine fibers and α1-adrenoreceptor expression in the POAH. Both E2 and ICR normalized the norepinephrine pathway, but E2 achieved greater effects than ICR. ICR had different effects in different nuclei in the POAH and its therapeutic effect was better in the LC.
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Affiliation(s)
- Wenjuan Wang
- Anatomy and Embryology Department, Peking University Health Science Center, Beijing, PR China
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