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Cope ZA, Murai T, Sukoff Rizzo SJ. Emerging Electroencephalographic Biomarkers to Improve Preclinical to Clinical Translation in Alzheimer’s Disease. Front Aging Neurosci 2022; 14:805063. [PMID: 35250541 PMCID: PMC8891809 DOI: 10.3389/fnagi.2022.805063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 01/26/2022] [Indexed: 11/18/2022] Open
Abstract
Continually emerging data indicate that sub-clinical, non-convulsive epileptiform activity is not only prevalent in Alzheimer’s disease (AD) but is detectable early in the course of the disease and predicts cognitive decline in both humans and animal models. Epileptiform activity and other electroencephalographic (EEG) measures may hold powerful, untapped potential to improve the translational validity of AD-related biomarkers in model animals ranging from mice, to rats, and non-human primates. In this review, we will focus on studies of epileptiform activity, EEG slowing, and theta-gamma coupling in preclinical models, with particular focus on its role in cognitive decline and relevance to AD. Here, each biomarker is described in the context of the contemporary literature and recent findings in AD relevant animal models are discussed.
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Amat-Foraster M, Leiser SC, Herrik KF, Richard N, Agerskov C, Bundgaard C, Bastlund JF, de Jong IE. The 5-HT6 receptor antagonist idalopirdine potentiates the effects of donepezil on gamma oscillations in the frontal cortex of anesthetized and awake rats without affecting sleep-wake architecture. Neuropharmacology 2017; 113:45-59. [DOI: 10.1016/j.neuropharm.2016.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/14/2016] [Accepted: 09/15/2016] [Indexed: 01/21/2023]
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Papazoglou A, Lundt A, Wormuth C, Ehninger D, Henseler C, Soós J, Broich K, Weiergräber M. Non-restraining EEG Radiotelemetry: Epidural and Deep Intracerebral Stereotaxic EEG Electrode Placement. J Vis Exp 2016. [PMID: 27404845 DOI: 10.3791/54216] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Implantable EEG radiotelemetry is of central relevance in the neurological characterization of transgenic mouse models of neuropsychiatric and neurodegenerative diseases as well as epilepsies. This powerful technique does not only provide valuable insights into the underlying pathophysiological mechanisms, i.e., the etiopathogenesis of CNS related diseases, it also facilitates the development of new translational, i.e., therapeutic approaches. Whereas competing techniques that make use of recorder systems used in jackets or tethered systems suffer from their unphysiological restraining to semi-restraining character, radiotelemetric EEG recordings overcome these disadvantages. Technically, implantable EEG radiotelemetry allows for precise and highly sensitive measurement of epidural and deep, intracerebral EEGs under various physiological and pathophysiological conditions. First, we present a detailed protocol of a straight forward, successful, quick and efficient technique for epidural (surface) EEG recordings resulting in high-quality electrocorticograms. Second, we demonstrate how to implant deep, intracerebral EEG electrodes, e.g., in the hippocampus (electrohippocampogram). For both approaches, a computerized 3D stereotaxic electrode implantation system is used. The radiofrequency transmitter itself is implanted into a subcutaneous pouch in both mice and rats. Special attention also has to be paid to pre-, peri- and postoperative treatment of the experimental animals. Preoperative preparation of mice and rats, suitable anesthesia as well as postoperative treatment and pain management are described in detail.
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Affiliation(s)
- Anna Papazoglou
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Andreas Lundt
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Carola Wormuth
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Dan Ehninger
- Molecular and Cellular Cognition Lab, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE)
| | - Christina Henseler
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Julien Soós
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Karl Broich
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)
| | - Marco Weiergräber
- Department of Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM);
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EEG Radiotelemetry in Small Laboratory Rodents: A Powerful State-of-the Art Approach in Neuropsychiatric, Neurodegenerative, and Epilepsy Research. Neural Plast 2015; 2016:8213878. [PMID: 26819775 PMCID: PMC4706962 DOI: 10.1155/2016/8213878] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/27/2015] [Indexed: 02/04/2023] Open
Abstract
EEG radiotelemetry plays an important role in the neurological characterization of transgenic mouse models of neuropsychiatric and neurodegenerative diseases as well as epilepsies providing valuable insights into underlying pathophysiological mechanisms and thereby facilitating the development of new translational approaches. We elaborate on the major advantages of nonrestraining EEG radiotelemetry in contrast to restraining procedures such as tethered systems or jacket systems containing recorders. Whereas a main disadvantage of the latter is their unphysiological, restraining character, telemetric EEG recording overcomes these disadvantages. It allows precise and highly sensitive measurement under various physiological and pathophysiological conditions. Here we present a detailed description of a straightforward successful, quick, and efficient technique for intraperitoneal as well as subcutaneous pouch implantation of a standard radiofrequency transmitter in mice and rats. We further present computerized 3D-stereotaxic placement of both epidural and deep intracerebral electrodes. Preoperative preparation of mice and rats, suitable anaesthesia, and postoperative treatment and pain management are described in detail. A special focus is on fields of application, technical and experimental pitfalls, and technical connections of commercially available radiotelemetry systems with other electrophysiological setups.
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Leiser SC, Iglesias-Bregna D, Westrich L, Pehrson AL, Sanchez C. Differentiated effects of the multimodal antidepressant vortioxetine on sleep architecture: Part 2, pharmacological interactions in rodents suggest a role of serotonin-3 receptor antagonism. J Psychopharmacol 2015; 29:1092-105. [PMID: 26174134 PMCID: PMC4579402 DOI: 10.1177/0269881115592347] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Antidepressants often disrupt sleep. Vortioxetine, a multimodal antidepressant acting through serotonin (5-HT) transporter (SERT) inhibition, 5-HT3, 5-HT7 and 5-HT1D receptor antagonism, 5-HT1B receptor partial agonism, and 5-HT1A receptor agonism, had fewer incidences of sleep-related adverse events reported in depressed patients. In the accompanying paper a polysomnographic electroencephalography (sleep-EEG) study of vortioxetine and paroxetine in healthy subjects indicated that at low/intermediate levels of SERT occupancy, vortioxetine affected rapid eye movement (REM) sleep differently than paroxetine. Here we investigated clinically meaningful doses (80-90% SERT occupancy) of vortioxetine and paroxetine on sleep-EEG in rats to further elucidate the serotoninergic receptor mechanisms mediating this difference. Cortical EEG, electromyography (EMG), and locomotion were recorded telemetrically for 10 days, following an acute dose, from rats receiving vortioxetine-infused chow or paroxetine-infused water and respective controls. Sleep stages were manually scored into active wake, quiet wake, and non-REM or REM sleep. Acute paroxetine or vortioxetine delayed REM onset latency (ROL) and decreased REM episodes. After repeated administration, vortioxetine yielded normal sleep-wake rhythms while paroxetine continued to suppress REM. Paroxetine, unlike vortioxetine, increased transitions from non-REM to wake, suggesting fragmented sleep. Next, we investigated the role of 5-HT3 receptors in eliciting these differences. The 5-HT3 receptor antagonist ondansetron significantly reduced paroxetine's acute effects on ROL, while the 5-HT3 receptor agonist SR57227A significantly increased vortioxetine's acute effect on ROL. Overall, our data are consistent with the clinical findings that vortioxetine impacts REM sleep differently than paroxetine, and suggests a role for 5-HT3 receptor antagonism in mitigating these differences.
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Nagahara T, Saitoh T, Kutsumura N, Irukayama-Tomobe Y, Ogawa Y, Kuroda D, Gouda H, Kumagai H, Fujii H, Yanagisawa M, Nagase H. Design and Synthesis of Non-Peptide, Selective Orexin Receptor 2 Agonists. J Med Chem 2015; 58:7931-7. [PMID: 26267383 DOI: 10.1021/acs.jmedchem.5b00988] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Orexins are a family of neuropeptides that regulate sleep/wakefulness, acting on two G-protein-coupled receptors, orexin receptors 1 (OX1R) and 2 (OX2R). Genetic and pharmacologic evidence suggests that orexin receptor agonists, especially OX2R agonist, will be useful for mechanistic therapy of the sleep disorder narcolepsy/cataplexy. We herein report the discovery of a potent (EC50 on OX2R is 0.023 μM) and OX2R-selective (OX1R/OX2R EC50 ratio is 70) agonist, 4'-methoxy-N,N-dimethyl-3'-[N-(3-{[2-(3-methylbenzamido)ethyl]amino}phenyl)sulfamoyl]-(1,1'-biphenyl)-3-carboxamide 26.
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Affiliation(s)
- Takashi Nagahara
- Department of Medicinal Chemistry, School of Pharmacy, Kitasato University , 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Tsuyoshi Saitoh
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Noriki Kutsumura
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoko Irukayama-Tomobe
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yasuhiro Ogawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Daisuke Kuroda
- School of Pharmacy, Showa University , 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Hiroaki Gouda
- School of Pharmacy, Showa University , 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Hidetoshi Kumagai
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,Department of Molecular Genetics, University of Texas Southwestern Medical Center , Dallas, Texas 75390-8584, United States
| | - Hideaki Fujii
- Department of Medicinal Chemistry, School of Pharmacy, Kitasato University , 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
| | - Masashi Yanagisawa
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,Department of Molecular Genetics, University of Texas Southwestern Medical Center , Dallas, Texas 75390-8584, United States
| | - Hiroshi Nagase
- International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba , 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.,Department of Medicinal Chemistry, School of Pharmacy, Kitasato University , 5-9-1 Shirokane, Minato-ku, Tokyo 108-8641, Japan
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Leiser SC, Pehrson AL, Robichaud PJ, Sanchez C. Multimodal antidepressant vortioxetine increases frontal cortical oscillations unlike escitalopram and duloxetine--a quantitative EEG study in rats. Br J Pharmacol 2015; 171:4255-72. [PMID: 24846338 PMCID: PMC4241092 DOI: 10.1111/bph.12782] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 04/27/2014] [Accepted: 05/03/2014] [Indexed: 12/28/2022] Open
Abstract
Background and Purpose EEG studies show that 5-HT is involved in regulation of sleep–wake state and modulates cortical oscillations. Vortioxetine is a 5-HT3, 5-HT7, and 5-HT1D receptor antagonist, 5-HT1B partial agonist, 5-HT1A agonist, and 5-HT transporter inhibitor. Preclinical (animal) and clinical studies with vortioxetine show positive impact on cognitive metrics involving cortical function. Here we assess vortioxetine's effect on cortical neuronal oscillations in actively awake rats. Experimental Approach Telemetric EEG recordings were obtained with the following treatments (mg·kg−1, s.c.): vehicle, vortioxetine (0.1, 1.0, 3.0, 10), 5-HT1A agonist flesinoxan (2.5), 5-HT3 antagonist ondansetron (0.30), 5-HT7 antagonist SB-269970-A (10), escitalopram (2.0), duloxetine (10) and vortioxetine plus flesinoxan. Target occupancies were determined by ex vivo autoradiography. Key Results Vortioxetine dose-dependently increased wakefulness. Flesinoxan, duloxetine, ondansetron, but not escitalopram or SB-269970-A increased wakefulness. Quantitative spectral analyses showed vortioxetine alone and with flesinoxan increased θ (4–8 Hz), α (8–12 Hz) and γ (30–50 Hz) power. Duloxetine had no effect on θ and γ, but decreased α power, while escitalopram produced no changes. Ondansetron and SB-269970 (≈31–35% occupancy) increased θ power. Flesinoxan (≈41% occupancy) increased θ and γ power. Conclusions and Implications Vortioxetine increased wakefulness and increased frontal cortical activity, most likely because of its 5-HT7 and 5-HT3 antagonism and 5-HT1A agonism. Vortioxetine differs from escitalopram and duloxetine by increasing cortical θ, α and γ oscillations. These preclinical findings suggest a role of vortioxetine in modulating cortical circuits known to be recruited during cognitive behaviours and warrant further investigation as to their clinical impact.
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Affiliation(s)
- S C Leiser
- Department of BioAnalysis & Physiology, Lundbeck Research USA, Inc., Paramus, NJ, USA
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Dale E, Zhang H, Leiser SC, Xiao Y, Lu D, Yang CR, Plath N, Sanchez C. Vortioxetine disinhibits pyramidal cell function and enhances synaptic plasticity in the rat hippocampus. J Psychopharmacol 2014; 28:891-902. [PMID: 25122043 PMCID: PMC4230848 DOI: 10.1177/0269881114543719] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Vortioxetine, a novel antidepressant with multimodal action, is a serotonin (5-HT)3, 5-HT7 and 5-HT1D receptor antagonist, a 5-HT1B receptor partial agonist, a 5-HT1A receptor agonist and a 5-HT transporter (SERT) inhibitor. Vortioxetine has been shown to improve cognitive performance in several preclinical rat models and in patients with major depressive disorder. Here we investigated the mechanistic basis for these effects by studying the effect of vortioxetine on synaptic transmission, long-term potentiation (LTP), a cellular correlate of learning and memory, and theta oscillations in the rat hippocampus and frontal cortex. Vortioxetine was found to prevent the 5-HT-induced increase in inhibitory post-synaptic potentials recorded from CA1 pyramidal cells, most likely by 5-HT3 receptor antagonism. Vortioxetine also enhanced LTP in the CA1 region of the hippocampus. Finally, vortioxetine increased fronto-cortical theta power during active wake in whole animal electroencephalographic recordings. In comparison, the selective SERT inhibitor escitalopram showed no effect on any of these measures. Taken together, our results indicate that vortioxetine can increase pyramidal cell output, which leads to enhanced synaptic plasticity in the hippocampus. Given the central role of the hippocampus in cognition, these findings may provide a cellular correlate to the observed preclinical and clinical cognition-enhancing effects of vortioxetine.
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Affiliation(s)
| | | | | | - Yixin Xiao
- Shanghai Chempartner Co. Ltd., Shanghai, China
| | - Dunguo Lu
- Shanghai Chempartner Co. Ltd., Shanghai, China
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Carballosa-Gonzalez MM, Muñoz LJ, López-Alburquerque T, Pardal-Fernández JM, Nava E, de Cabo C, Sancho C, López DE. EEG characterization of audiogenic seizures in the hamster strain GASH:Sal. Epilepsy Res 2013; 106:318-25. [PMID: 23916142 DOI: 10.1016/j.eplepsyres.2013.07.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 06/27/2013] [Accepted: 07/02/2013] [Indexed: 12/16/2022]
Abstract
The study was performed to characterize GASH:SAL audiogenic seizures as true epileptic activity based on electroencephalographic markers acquired with a wireless implanted radiotelemetry system. We analyzed cortical EEG patterns synchronized with video recordings of convulsive behavior of the GASH:Sal hamster following an acoustic stimulus. All GASH:Sal presented archetypal motor symptoms comparable to current animal models of generalized tonic-clonic epilepsy. Seizures consisted of an initial bout of wild running, followed by opisthotonus, tonic-clonic convulsions, tonic limb extension, and terminated in postictal depression. EEG patterns correlated with behavior and displayed phase appropriate spike-wave complexes, low-amplitude desynchronized activity, and high frequency large-amplitude peaks. Our results confirm that electroencephalographic profiles of the audiogenic seizures of the hamster GASH:Sal are parallel to EEG patterns of other animal models of generalized tonic-clonic seizures. Therefore, this animal may serve as an appropriate model for epilepsy research.
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Affiliation(s)
- Melissa M Carballosa-Gonzalez
- Instituto de Neurociencias de Castilla y León/IBSAL, C/ Pintor Fernando Gallego, n° 1, 37007 Salamanca, Spain; The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, 1095 NW 14th Terrace, Room 2-34, Miami, FL 33136, USA
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Jones-Bolin S. Guidelines for the care and use of laboratory animals in biomedical research. ACTA ACUST UNITED AC 2013; Appendix 4:Appendix 4B. [PMID: 23258596 DOI: 10.1002/0471141755.pha04bs59] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This unit provides a general overview on topics related to the practical care and use of laboratory animals in biomedical research. These topics are briefly described and provide Web sites and/or research articles that can be accessed for more detailed information. While the primary focus is on the care and use of rats and mice bred for biomedical research, many of the Web sites listed provide information on other species used for this purpose.
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Nguyen CTO, Brain P, Ivarsson M. Comparing activity analyses for improved accuracy and sensitivity of drug detection. J Neurosci Methods 2011; 204:374-8. [PMID: 22138631 DOI: 10.1016/j.jneumeth.2011.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 11/03/2011] [Accepted: 11/04/2011] [Indexed: 11/29/2022]
Abstract
Activity (or locomotion) can be one of the most sensitive and broadly affected translatable biomarkers of drug or disease. However activity data often have variance heterogeneity and periods with zero activity, and thus is usually not normally distributed giving the possibility of false interpretation of the data. We attempt to address this issue by developing and comparing different analysis techniques. These include transforming the data (square root and ln) as well as determining the probability of activity. In order to comprehensively assess these analysis techniques they are applied to a variety of different activity data sets, which have varying pharmacological manipulation or diurnal cycle state. These analyses indicate that activity data can firstly be improved by a square root transform of the data, which reduces variance heterogeneity. A further improved step is to analyse the "probability of moving", which is the most sensitive methodology to detect a change in activity. Thus analysis of the powerful non-invasive physiological marker activity and locomotion can be easily and simply modified to improve accuracy and sensitivity in disease or drug detection.
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Affiliation(s)
- Christine T O Nguyen
- Pfizer Global Research and Development, Ramsgate Road, Sandwich, Kent CT13 9NJ, UK.
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Cao M, Guilleminault C. Hypocretin and its emerging role as a target for treatment of sleep disorders. Curr Neurol Neurosci Rep 2011; 11:227-34. [PMID: 21170610 DOI: 10.1007/s11910-010-0172-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The neuropeptides hypocretin-1 and -2 (orexin A and B) are critical in the regulation of arousal and maintenance of wakefulness. Understanding the role of the hypocretin system in sleep/wake regulation has come from narcolepsy-cataplexy research. Deficiency of hypocretin results in loss of sleep/wake control with consequent unstable transitions from wakefulness into non-rapid eye movement (REM) and REM sleep, and clinical manifestations including daytime hypersomnolence, sleep attacks, and cataplexy. The hypocretin system regulates sleep/wake control through complex interactions between monoaminergic/cholinergic wake-promoting and GABAergic sleep-promoting neuronal systems. Research for the hypocretin agonist and the hypocretin antagonist for the treatment of sleep disorders has vigorously increased over the past 10 years. This review will focus on the origin, functions, and mechanisms in which the hypocretin system regulates sleep and wakefulness, and discuss its emerging role as a target for the treatment of sleep disorders.
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Affiliation(s)
- Michelle Cao
- Stanford University Sleep Medicine, 450 Broadway Street, Pavilion C, 2nd Floor, M/C 5704, Redwood City, CA 94063, USA.
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Morairty SR, Wisor J, Silveira K, Sinko W, Kilduff TS. The wake-promoting effects of hypocretin-1 are attenuated in old rats. Neurobiol Aging 2009; 32:1514-27. [PMID: 19781813 DOI: 10.1016/j.neurobiolaging.2009.07.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 06/01/2009] [Accepted: 07/27/2009] [Indexed: 11/16/2022]
Abstract
Disruption of sleep is a frequent complaint among elderly humans and is also evident in aged laboratory rodents. The neurobiological bases of age-related sleep/wake disruption are unknown. Given the critical role of the hypocretins in sleep/wake regulation, we sought to determine whether the wake-promoting effect of hypocretin changes with age in Wistar rats, a strain in which age-related changes in both sleep and hypocretin signaling have been reported. Intracerebroventricular infusions of hypocretin-1 (10 and 30 μg) significantly increased wake time relative to vehicle in both young (3 mos) and old (25 mos) Wistar rats. However, the magnitude and duration of the wake-promoting effects were attenuated with age. An increase of parameters associated with homeostatic sleep recovery after sleep deprivation, including non-rapid eye movement (NR) sleep time, NR delta power, the ratio of NR to rapid eye movement (REM) sleep, and NR consolidation, occurred subsequent to Hcrt-induced waking in young but not old rats. ICV infusions of hypocretin-2 (10 and 30 μg) produced fewer effects in both young and old rats. These data demonstrate that activation of a major sleep/wake regulatory pathway is attenuated in old rats.
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Beig MI, Chandra R, Talwar A, Fahim M, Katyal A. Epileptic seizure-induced hypertension and its prevention by calcium channel blockers: a real-time study in conscious telemetered rats. Can J Physiol Pharmacol 2009; 87:572-80. [PMID: 19767881 DOI: 10.1139/y09-034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epileptic seizures are accompanied by changes in autonomic function that in turn influence the cardiovascular system (hypertension and bradyarrhythmia). We have studied possible cardioprotective activity (during the ictal state in conscious animals) of valproic acid, nifedipine, and verapamil, alone and in combination, during pentylenetetrazole (PTZ)-induced seizures. Telemetry system was used for recording EEG, blood pressure, and heart rate in conscious, freely moving rats during seizures. We observed that PTZ-induced seizures were accompanied by hypertension and bradyarrhythmia. Pretreatment with valproic acid did not block seizure-induced hypertension and bradyarrhythmia. Nifedipine alone and in combination with valproic acid blocked seizure-induced hypertension and bradyarrhythmia significantly. We also observed that pretreatment with verapamil alone and in combination with valproic acid did not block seizure-induced hypertension and bradyarrhythmia significantly. Our results suggest that pretreatment with nifedipine alone or in combination with valproic acid provides protection against seizure-induced hypertension and bradyarrhythmia.
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Affiliation(s)
- Mirza Irfan Beig
- Dr. B.R. Ambedkar Center for Biomedical Research, University of Delhi, Delhi 110 007, India
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15
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Ebert B, Anderson NJ, Cremers TI, Rasmussen S, Vogel V, Fahey JM, Sánchez C. Gaboxadol — a different hypnotic profile with no tolerance to sleep EEG and sedative effects after repeated daily dosing. Pharmacol Biochem Behav 2008; 90:113-22. [DOI: 10.1016/j.pbb.2008.01.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2007] [Revised: 01/17/2008] [Accepted: 01/22/2008] [Indexed: 10/22/2022]
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Ohno K, Sakurai T. Orexin neuronal circuitry: role in the regulation of sleep and wakefulness. Front Neuroendocrinol 2008; 29:70-87. [PMID: 17910982 DOI: 10.1016/j.yfrne.2007.08.001] [Citation(s) in RCA: 201] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2007] [Revised: 08/06/2007] [Accepted: 08/08/2007] [Indexed: 11/26/2022]
Abstract
Orexin A and orexin B were initially identified as endogenous ligands for two orphan G protein-coupled receptors [104]. They were initially recognized as regulators of feeding behavior in view of their exclusive production in the lateral hypothalamic area (LHA), a region known as the feeding center, and their pharmacological activity [104,30,49,107]. Subsequently, the finding that orexin deficiency causes narcolepsy in humans and animals suggested that these hypothalamic neuropeptides play a critical role in regulating sleep/wake cycle [22,46,71,95,117]. These peptides activate waking-active monoaminergic and cholinergic neurons in the hypothalamus/brain stem regions to maintain a long, consolidated awake period. Recent studies on efferent and afferent systems of orexin neurons, and phenotypic characterization of genetically modified mice in the orexin system further suggested roles of orexin in the coordination of emotion, energy homeostasis, reward system, and arousal [3,80,106,137]. A link between the limbic system and orexin neurons might be important for increasing vigilance during emotional stimuli. Orexin neurons are also regulated by peripheral metabolic cues, including ghrelin, leptin, and glucose, suggesting that they might have important roles as a link between energy homeostasis and vigilance states [137]. Recent research has also implicated orexins in reward systems and the mechanisms of drug addiction [13,48,91]. These observations suggest that orexin neurons sense the outer and inner environment of the body, and maintain proper wakefulness of animals for survival. This review discusses the mechanism by which orexins maintain sleep/wakefulness states, and how this mechanism relates to other systems that regulate emotion, reward, and energy homeostasis.
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Affiliation(s)
- Kousaku Ohno
- Department of Pharmacology, Institute of Basic Medical Science, University of Tsukuba, Tsukuba, Ibaraki 305-8575, Japan
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Beig MI, Bhagat N, Talwar A, Chandra R, Fahim M, Katyal A. Simultaneous recording of electroencephalogram and blood pressure in conscious telemetered rats during ictal state. J Pharmacol Toxicol Methods 2007; 56:51-7. [PMID: 17336099 DOI: 10.1016/j.vascn.2006.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Accepted: 12/20/2006] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Seizures are accompanied by autonomic dysfunction which in turn influences cardiovascular variables. A method for simultaneous acquisition of electroencephalogram (EEG) and arterial blood pressure (BP) during seizures in conscious animals has not previously been described. METHODS The effect of pentylenetetrazole (PTZ) was first studied on isolated rat atria. EEG and BP were then monitored simultaneously in conscious rats, with a chronically implanted radiotelemetric device. Changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and heart rate (HR) during epileptiform seizures induced by intraperitoneal administration of PTZ were monitored to validate the method. RESULTS PTZ did not have significant inotropic or chronotropic effect in isolated atria. The radiotelemetry system used to acquire data in unrestrained conscious rats enabled us to study neurological excitation (EEG) and cardiovascular variables (BP and HR) during seizures. Our results demonstrated that this method can be used to study the effect of neuronal excitation on cardiovascular variables and vice versa.
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Affiliation(s)
- Mirza Irfan Beig
- Dr.B.R.Ambedkar Center for Biomedical Research, University of Delhi, Delhi, India
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Paterson LM, Wilson SJ, Nutt DJ, Hutson PH, Ivarsson M. A translational, caffeine-induced model of onset insomnia in rats and healthy volunteers. Psychopharmacology (Berl) 2007; 191:943-50. [PMID: 17225163 DOI: 10.1007/s00213-006-0672-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2006] [Accepted: 12/07/2006] [Indexed: 11/30/2022]
Abstract
RATIONALE Insomnia is a common and disabling complaint for which there is a need for improved treatments. Successful drug discovery relies on the use of appropriate animal models to assess likely outcome in the clinic. OBJECTIVES The purpose of this study was to develop a translational, caffeine-induced model of insomnia in rats and healthy volunteers. We used sleep onset latency (SOL) as a comparable sleep measure between the two species. The model was validated by two effective sleep-promoting agents with different pharmacology, zolpidem and trazodone, which have GABA-ergic and serotonergic mechanisms, respectively. MATERIALS AND METHODS In rats, radiotelemetry transmitters with electroencephalogram and electromyogram electrodes were implanted for sleep recording. Animals were administered with caffeine alone (10 mg/kg) or in combination with zolpidem (10 mg/kg) or trazodone (20 mg/kg), or vehicle, in crossover experiments. Home polysomnography was performed in 12 healthy male volunteers in a randomised, placebo-controlled, 4-week crossover study. Subjects received placebo, caffeine (150 mg) or caffeine in combination with zolpidem (10 mg) or trazodone (100 mg). Subjective sleep effects in volunteers were assessed using the Leeds Sleep Evaluation Questionnaire. RESULTS Caffeine caused a significant prolongation in objective SOL in rats and humans. This effect was sensitive to zolpidem and trazodone, both of which attenuated the caffeine-induced increase in SOL. Furthermore, both hypnotics restored the disruption in subjective measures of sleep onset caused by caffeine in volunteers. CONCLUSIONS This model therefore provides a promising paradigm in which we can study novel treatments for sleep disorders and an opportunity for direct comparison of results between rodents and humans.
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Affiliation(s)
- Louise M Paterson
- Psychopharmacology Unit, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol, BS1 3NY, UK
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Sánchez C, Brennum LT, Stórustovu SÍ, Kreilgård M, Mørk A. Depression and poor sleep: the effect of monoaminergic antidepressants in a pre-clinical model in rats. Pharmacol Biochem Behav 2007; 86:468-76. [PMID: 17303232 DOI: 10.1016/j.pbb.2007.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2006] [Revised: 12/27/2006] [Accepted: 01/10/2007] [Indexed: 10/23/2022]
Abstract
The effects of five antidepressants (escitalopram, paroxetine, duloxetine, venlafaxine, and reboxetine) on the sleep architecture were investigated in freely moving rats in the light phase of a 12:12 h light:dark cycle following a single i.p. dose of antidepressant. Overall, paroxetine and escitalopram exhibited the least sleep disruptive profiles, whereas duloxetine, venlafaxine, and reboxetine increased the time spent awake and suppressed paradoxical sleep. Analysis of the EEG at 1 h intervals revealed only subtle differences from the overall picture. The effect of venlafaxine on disruption of sleep architecture could not be readily explained by its in vitro serotonin (5-HT) and noradrenaline (NA) reuptake inhibitory potencies. In vivo microdialysis experiments in the ventral hippocampus of freely moving rats revealed that venlafaxine affected the 5-HT and NA systems equally at the doses tested. Duloxetine (7.7 mg/kg) induced maximal blockade of the 5-HT transporter and duloxetine 7.7 mg/kg also modulated the noradrenaline system. Thus, in this animal model, the enhancement of noradrenergic activity is more disruptive on the sleep architecture than enhancement of serotonergic activity.
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Affiliation(s)
- Connie Sánchez
- Neuroscience, Lundbeck Research USA Inc, Paramus, NJ 07652-1431, USA.
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20
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Thorpe AJ, Kotz CM. Orexin A in the nucleus accumbens stimulates feeding and locomotor activity. Brain Res 2005; 1050:156-62. [PMID: 15979595 DOI: 10.1016/j.brainres.2005.05.045] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 05/16/2005] [Accepted: 05/18/2005] [Indexed: 11/16/2022]
Abstract
Due to the nature of processing within the accumbens shell (AccSh) and the presence of orexin receptors and varicosities within the AccSh, we hypothesized that orexin A may partly regulate feeding behavior and locomotor activity via signaling in this site. To test this hypothesis, male Sprague-Dawley rats were implanted with guide cannulae directed to the medial portion of the AccSh. Orexin A (0, 100, 500, and 1000 pmol, in 0.5 microl artificial cerebrospinal fluid) was infused into the AccSh and feeding behavior and locomotor activity were monitored. The effect of pretreatment with an orexin 1 receptor antagonist (SB334867A) on orexin A-induced feeding and locomotor activity was assessed. Orexin A augmented feeding in the 0-1 h and 1-2 h post-infusion interval (P = 0.0058 and P = 0.025, respectively) and stimulated locomotor activity in the 30-60 min, 60-90 min, and 90-120 min post-infusion intervals (P <or= 0.0001, P = 0.0056 and P = 0.046, respectively). Orexin A-induced feeding was significantly attenuated by preadministration of SB334867A in the 0-1 h post-infusion time interval (P = 0.03). Orexin A-induced locomotor activity was not affected by SB334867A. These data support the hypothesis that the AccSh is a site of orexin A modulation of feeding behavior and locomotor activity.
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Affiliation(s)
- A J Thorpe
- Department of Neuroscience, University of Minnesota, 1334 Eckles Avenue, Saint Paul, MN 55108, USA
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Lestaevel P, Houpert P, Bussy C, Dhieux B, Gourmelon P, Paquet F. The brain is a target organ after acute exposure to depleted uranium. Toxicology 2005; 212:219-26. [PMID: 15951092 DOI: 10.1016/j.tox.2005.05.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2005] [Revised: 04/29/2005] [Accepted: 05/06/2005] [Indexed: 10/25/2022]
Abstract
The health effects of depleted uranium (DU) are mainly caused by its chemical toxicity. Although the kidneys are the main target organs for uranium toxicity, uranium can also reach the brain. In this paper, the central effects of acute exposure to DU were studied in relation to health parameters and the sleep-wake cycle of adult rats. Animals were injected intraperitoneally with 144+/-10 microg DU kg-1 as nitrate. Three days after injection, the amounts of uranium in the kidneys represented 2.6 microg of DU g-1 of tissue, considered as a sub-nephrotoxic dosage. The central effect of uranium could be seen through a decrease in food intake as early as the first day after exposure and shorter paradoxical sleep 3 days after acute DU exposure (-18% of controls). With a lower dosage of DU (70+/-8 microg DU kg-1), no significant effect was observed on the sleep-wake cycle. The present study intends to illustrate the fact that the brain is a target organ, as are the kidneys, after acute exposure to a moderate dosage of DU. The mechanisms by which uranium causes these early neurophysiological perturbations shall be discussed.
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Affiliation(s)
- P Lestaevel
- Institut de Radioprotection et de Sûreté Nucléaire, Département de Radio-Protection de l'Homme, Laboratoire de Radio-Toxicologie Expérimentale, BP 166, 26702 Pierrelatte, France.
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Bastlund JF, Jennum P, Mohapel P, Penschuck S, Watson WP. Spontaneous epileptic rats show changes in sleep architecture and hypothalamic pathology. Epilepsia 2005; 46:934-8. [PMID: 15946334 DOI: 10.1111/j.1528-1167.2005.63204.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE The goal of the present study was to investigate the relationship between sleep, hypothalamic pathology, and seizures in spontaneous epileptic rats. METHODS Rats were implanted with radiotelemetry transmitters for measuring electrocorticogram (ECoG) and stimulation electrodes in the hippocampus. Epileptogenesis was triggered by 2 h of electical stimulation-induced self-sustained status epilepticus (SSSE). After SSSE, ECoGs were monitored over a 15-week period for the occurrence of interictal high-amplitude low-frequency (HALF) acitvity and spontaneous reoccurring seizures (SRSs). RESULTS Spontaneous epileptic rats showed clinical features of temporal lobe epilepsy (TLE), such as spontaneous seizures, interictal activity and neuronal cell loss in the dorsomedial hypothalamus, a region important for normal sleep regulation. Interestingly, epileptic rats showed disturbances in sleep architecture, with a high percentage of the seizures occurring during sleep. CONCLUSIONS Therefore we conclude that a close association exists between epileptiform activity and alterations in sleep architecture that may be related to hypothalamic pathology.
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Weiergräber M, Henry M, Hescheler J, Smyth N, Schneider T. Electrocorticographic and deep intracerebral EEG recording in mice using a telemetry system. ACTA ACUST UNITED AC 2005; 14:154-64. [PMID: 15795169 DOI: 10.1016/j.brainresprot.2004.12.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Revised: 12/16/2004] [Accepted: 12/22/2004] [Indexed: 10/25/2022]
Abstract
Telemetric EEG recording plays a crucial role in the neurological characterization of various transgenic mouse models giving valuable information about epilepsies and sleep disorders in humans. In the past different experimental approaches have been described using tethered systems and jacket systems containing recorders. A main disadvantage of these is their sometimes unphysiological, restraining character. Telemetric EEG recording overcomes most of these disadvantages and allows precise and highly sensitive measurement under various physiological and pathophysiological conditions and different stages of consciousness, as during seizure activity and different sleep stages. Here we present the first contiguous, detailed description of a successful and quick technique for intraperitoneal implantation or subcutaneous pouch implantation of a radiofrequency transmitter in mice and subsequent lead placement in both epidural and deep intracerebral position. Preoperative preparation of the mice, suitable anesthesia, as well as postoperative treatment including pain management are described in detail to provide optimal postoperative recovery. Finally, we display examples of electrocorticograms and deep intracerebral recordings, present strategies to maximize signal-to-noise ratio, paying special attention to major pitfalls and possible artefacts occurring in telemetric EEG recording in mice.
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Affiliation(s)
- Marco Weiergräber
- Institute of Neurophysiology, University of Cologne, Robert-Koch-Street 39, 50931 Cologne, Germany
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Bastlund JF, Jennum P, Mohapel P, Vogel V, Watson WP. Measurement of cortical and hippocampal epileptiform activity in freely moving rats by means of implantable radiotelemetry. J Neurosci Methods 2004; 138:65-72. [PMID: 15325113 DOI: 10.1016/j.jneumeth.2004.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Revised: 03/03/2004] [Accepted: 03/08/2004] [Indexed: 11/18/2022]
Abstract
Implanted radiotelemetry has been used for the measurement of cortical electroencephalogram (EEG), locomotor activity, body temperature and cardiovascular parameters. This technique allows high quality data acquisition from freely moving animals with no complications of externalised apparatus. This paper focuses on the methodology for short and long-term monitoring of epileptiform activity by simultaneous cortical EEG, hippocampal (HC) EEG and electromyogram (EMG) in rats. The circadian rhythm of temperature (CRT) was monitored after surgery to estimate the need for post surgical recovery of animals. Different placements of EMG electrodes were assessed in order to minimise artefacts and increase sensitivity. The occurrence of epileptiform ictal and interictal activity following an acute injection of either 40 mg/kg pentylenetetrazole (PTZ) or 13.8 mg/kg kainic acid (KA) was investigated. The occurrence of spontaneous seizures was also monitored 5-8 weeks after administration of KA. The present study demonstrated a sensitive method for monitoring cortical EEG, hippocampal EEG and EMG short and long-term by implantable radiotelemetry in freely moving rats.
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Affiliation(s)
- Jesper F Bastlund
- Department of Neuropharmacology, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark.
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Abstract
The viral transneuronal labeling method was used to demonstrate that orexin-containing neurons of the lateral hypothalamic area (LHA) are linked via multisynaptic connections to different sympathetic outflow systems. Two different types of transneuronal tracing experiments were performed: single- and double-virus studies. In the first series of experiments, Bartha pseudorabies virus (PRV), a retrograde transneuronal tracer, was injected into single sympathetic targets, viz., stellate ganglion, adrenal gland, celiac ganglion, and kidney. Six to 7 days post-injection, orexin (hypocretin) neurons were transneuronally labeled. In a second set of experiments, the double-virus tracing method was used to determine whether single orexin LHA neurons are linked to two different sympathetic outflow systems. Two isogenic forms of Bartha PRV were used that differed by a single gene. beta-Galactosidase Bartha PRV was injected into the stellate ganglion and green fluorescent protein Bartha PRV into the adrenal gland of the same rat. The reverse placement of viral injections was made in another set of rats. In both paradigms, some orexin LHA neurons were transneuronally labeled with both viruses, indicating that they are capable of modulating multiple sympathetic outflow systems. These findings raise the possibility that orexin LHA neurons regulate general sympathetic functions, such as those that occur during arousal or the fight-or-flight response.
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Affiliation(s)
- J C Geerling
- Department of Anatomy and Neurobiology, Box 8108, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA
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