1
|
Stanyer EC, Hoffmann J, Holland PR. Orexins and primary headaches: an overview of the neurobiology and clinical impact. Expert Rev Neurother 2024; 24:487-496. [PMID: 38517280 PMCID: PMC11034548 DOI: 10.1080/14737175.2024.2328728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 02/19/2024] [Indexed: 03/23/2024]
Abstract
INTRODUCTION Primary headaches, including migraines and cluster headaches, are highly prevalent disorders that significantly impact quality of life. Several factors suggest a key role for the hypothalamus, including neuroimaging studies, attack periodicity, and the presence of altered homeostatic regulation. The orexins are two neuropeptides synthesized almost exclusively in the lateral hypothalamus with widespread projections across the central nervous system. They are involved in an array of functions including homeostatic regulation and nociception, suggesting a potential role in primary headaches. AREAS COVERED This review summarizes current knowledge of the neurobiology of orexins, their involvement in sleep-wake regulation, nociception, and functions relevant to the associated symptomology of headache disorders. Preclinical reports of the antinociceptive effects of orexin-A in preclinical models are discussed, as well as clinical evidence for the potential involvement of the orexinergic system in headache. EXPERT OPINION Several lines of evidence support the targeted modulation of orexinergic signaling in primary headaches. Critically, orexins A and B, acting differentially via the orexin 1 and 2 receptors, respectively, demonstrate differential effects on trigeminal pain processing, indicating why dual-receptor antagonists failed to show clinical efficacy. The authors propose that orexin 1 receptor agonists or positive allosteric modulators should be the focus of future research.
Collapse
Affiliation(s)
- Emily C. Stanyer
- Headache Group, Wolfson Sensory, Pain and Regeneration Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
- Sir Jules Thorne Sleep and Circadian Neuroscience Institute, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Jan Hoffmann
- Headache Group, Wolfson Sensory, Pain and Regeneration Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Philip R. Holland
- Headache Group, Wolfson Sensory, Pain and Regeneration Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| |
Collapse
|
2
|
Collier AD, Yasmin N, Karatayev O, Abdulai AR, Yu B, Fam M, Campbell S, Leibowitz SF. Embryonic ethanol exposure and optogenetic activation of hypocretin neurons stimulate similar behaviors early in life associated with later alcohol consumption. Sci Rep 2024; 14:3021. [PMID: 38321123 PMCID: PMC10847468 DOI: 10.1038/s41598-024-52465-x] [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: 06/13/2023] [Accepted: 01/18/2024] [Indexed: 02/08/2024] Open
Abstract
The initiation of alcohol use early in life is one of the strongest predictors of developing a future alcohol use disorder. Clinical studies have identified specific behaviors during early childhood that predict an increased risk for excess alcohol consumption later in life. These behaviors, including increased hyperactivity, anxiety, novelty-seeking, exploratory behavior, impulsivity, and alcohol-seeking, are similarly stimulated in children and adolescent offspring of mothers who drink alcohol during pregnancy. Here we tested larval zebrafish in addition to young pre-weanling rats and found this repertoire of early behaviors along with the overconsumption of alcohol during adolescence to be increased by embryonic ethanol exposure. With hypocretin/orexin (Hcrt) neurons known to be stimulated by ethanol and involved in mediating these alcohol-related behaviors, we tested their function in larval zebrafish and found optogenetic activation of Hcrt neurons to stimulate these same early alcohol-related behaviors and later alcohol intake, suggesting that these neurons have an important role in producing these behaviors. Together, these results show zebrafish to be an especially useful animal model for investigating the diverse neuronal systems mediating behavioral changes at young ages that are produced by embryonic ethanol exposure and predict an increased risk for developing alcohol use disorder.
Collapse
Affiliation(s)
- Adam D Collier
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Nushrat Yasmin
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Olga Karatayev
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Abdul R Abdulai
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Boyi Yu
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Milisia Fam
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Samantha Campbell
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA
| | - Sarah F Leibowitz
- Laboratory of Behavioral Neurobiology, The Rockefeller University, 1230 York Avenue, New York, NY, 10065, USA.
| |
Collapse
|
3
|
Santin MDN, Tempier N, Belaid H, Zenoni M, Dumas S, Wallén-Mackenzie Å, Bardinet E, Destrieux C, François C, Karachi C. Anatomical characterisation of three different psychosurgical targets in the subthalamic area: from the basal ganglia to the limbic system. Brain Struct Funct 2023; 228:1977-1992. [PMID: 37668733 DOI: 10.1007/s00429-023-02691-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 07/24/2023] [Indexed: 09/06/2023]
Abstract
Effective neural stimulation for the treatment of severe psychiatric disorders needs accurate characterisation of surgical targets. This is especially true for the medial subthalamic region (MSR) which contains three targets: the anteromedial STN for obsessive compulsive disorder (OCD), the medial forebrain bundle (MFB) for depression and OCD, and the "Sano triangle" for pathological aggressiveness. Blocks containing the subthalamic area were obtained from two human brains. After obtaining 11.7-Tesla MRI, blocks were cut in regular sections for immunohistochemistry. Fluorescent in situ hybridisation was performed on the macaque MSR. Electron microscopic observation for synaptic specialisation was performed on human and macaque subthalamic fresh samples. Images of human brain sections were reconstructed in a cryoblock which was registered on the MRI and histological slices were then registered. The STN contains glutamatergic and fewer GABAergic neurons and has no strict boundary with the adjacent MSR. The anteromedial STN has abundant dopaminergic and serotoninergic innervation with very sparse dopaminergic neurons. The MFB is composed of dense anterior dopaminergic and posterior serotoninergic fibres, and fewer cholinergic and glutamatergic fibres. Medially, the Sano triangle presumably contains orexinergic terminals from the hypothalamus, and neurons with strong nuclear oestrogen receptor-alpha staining with a decreased anteroposterior and mediolateral gradient of staining. These findings provide new insight regarding MSR cells and their fibre specialisation, forming a transition zone between the basal ganglia and the limbic systems. Our 3D reconstruction enabled us to visualize the main histological features of the three targets which should enable better targeting and understanding of neuromodulatory stimulation results in severe psychiatric conditions.
Collapse
Affiliation(s)
- Marie des Neiges Santin
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Nicolas Tempier
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Hayat Belaid
- Service de Neurochirurgie, Hôpital Fondation Adolphe de Rothschild, 29 rue Manin, Paris, France
| | - Matthieu Zenoni
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | | | - Åsa Wallén-Mackenzie
- Department of Organismal Biology, Unit of Comparative Physiology, Uppsala University, S-756 32, Uppsala, Sweden
| | - Eric Bardinet
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Christophe Destrieux
- UMR Inserm U1253, IBrain, Université de Tours, Tours, France
- Laboratoire d'Anatomie, Faculté de Médecine, Université François Rabelais, Tours, France
| | - Chantal François
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Carine Karachi
- Sorbonne Université, Institut du Cerveau-Paris Brain Institute- ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France.
- AP-HP, Hôpital de la Pitié-Salpêtrière, Service de Neurochirurgie, Paris, France.
| |
Collapse
|
4
|
Bouâouda H, Jha PK. Orexin and MCH neurons: regulators of sleep and metabolism. Front Neurosci 2023; 17:1230428. [PMID: 37674517 PMCID: PMC10478345 DOI: 10.3389/fnins.2023.1230428] [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: 05/28/2023] [Accepted: 08/07/2023] [Indexed: 09/08/2023] Open
Abstract
Sleep-wake and fasting-feeding are tightly coupled behavioral states that require coordination between several brain regions. The mammalian lateral hypothalamus (LH) is a functionally and anatomically complex brain region harboring heterogeneous cell populations that regulate sleep, feeding, and energy metabolism. Significant attempts were made to understand the cellular and circuit bases of LH actions. Rapid advancements in genetic and electrophysiological manipulation help to understand the role of discrete LH cell populations. The opposing action of LH orexin/hypocretin and melanin-concentrating hormone (MCH) neurons on metabolic sensing and sleep-wake regulation make them the candidate to explore in detail. This review surveys the molecular, genetic, and neuronal components of orexin and MCH signaling in the regulation of sleep and metabolism.
Collapse
Affiliation(s)
- Hanan Bouâouda
- Pharmacology Institute, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Pawan Kumar Jha
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
5
|
Ten-Blanco M, Flores Á, Cristino L, Pereda-Pérez I, Berrendero F. Targeting the orexin/hypocretin system for the treatment of neuropsychiatric and neurodegenerative diseases: from animal to clinical studies. Front Neuroendocrinol 2023; 69:101066. [PMID: 37015302 DOI: 10.1016/j.yfrne.2023.101066] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 03/15/2023] [Accepted: 03/30/2023] [Indexed: 04/06/2023]
Abstract
Orexins (also known as hypocretins) are neuropeptides located exclusively in hypothalamic neurons that have extensive projections throughout the central nervous system and bind two different G protein-coupled receptors (OX1R and OX2R). Since its discovery in 1998, the orexin system has gained the interest of the scientific community as a potential therapeutic target for the treatment of different pathological conditions. Considering previous basic science research, a dual orexin receptor antagonist, suvorexant, was the first orexin agent to be approved by the US Food and Drug Administration to treat insomnia. In this review, we discuss and update the main preclinical and human studies involving the orexin system with several psychiatric and neurodegenerative diseases. This system constitutes a nice example of how basic scientific research driven by curiosity can be the best route to the generation of new and powerful pharmacological treatments.
Collapse
Affiliation(s)
- Marc Ten-Blanco
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - África Flores
- Pharmacology Unit, Department of Pathology and Experimental Therapeutics, Neurosciences Institute, University of Barcelona and Bellvitge University Hospital-IDIBELL, 08908 L'Hospitalet de Llobregat, Barcelona, Spain
| | - Luigia Cristino
- Endocannabinoid Research Group, Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), Pozzuoli, Italy
| | - Inmaculada Pereda-Pérez
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain
| | - Fernando Berrendero
- Faculty of Experimental Sciences, Universidad Francisco de Vitoria, 28223 Pozuelo de Alarcón, Madrid, Spain.
| |
Collapse
|
6
|
Sex-dependent role of orexin deficiency in feeding behavior and affective state of mice following intermittent access to a Western diet - Implications for binge-like eating behavior. Physiol Behav 2023; 260:114069. [PMID: 36572152 DOI: 10.1016/j.physbeh.2022.114069] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/02/2022] [Accepted: 12/22/2022] [Indexed: 12/24/2022]
Abstract
Binge eating disorder is a debilitating disease characterized by recurrent episodes of excessive food consumption and associated with psychiatric comorbidities. Despite a growing body of research investigating the neurobiological underpinnings of eating disorders, specific treatments are lacking. Given its fundamental role in feeding behaviors, we investigated the role of the orexin (hypocretin) neuropeptide system in binge-like eating and associated phenotypes. Specifically, we submitted female and male orexin-deficient mice to a paradigm of intermittent access (once weekly for 24 h) to a Western diet (WD) to induce binge-like eating. Additionally, we measured their anxiety-like behavior and plasma corticosterone levels. All mice showed binge-like eating in response to the intermittent WD access, but females did so to a greater extent than males. While orexin deficiency did not affect binge-like eating in this paradigm, we found that female orexin-deficient mice generally weighed more, and they expressed increased hypophagia and stress levels compared to wild-type mice following binge-like eating episodes. These detrimental effects of orexin deficiency were marginal or absent in males. Moreover, male wild-type mice expressed post-binge anxiety, but orexin-deficient mice did not. In conclusion, these results extend our knowledge of orexin's role in dysregulated eating and associated negative affective states, and contribute to the growing body of evidence indicating a sexual dimorphism of the orexin system. Considering that many human disorders, and especially eating disorders, have a strong sex bias, our findings further emphasize the importance of testing both female and male subjects.
Collapse
|
7
|
Palagini L, Geoffroy PA, Balestrieri M, Miniati M, Biggio G, Liguori C, Menicucci D, Ferini-Strambi L, Nobili L, Riemann D, Gemignani A. Current models of insomnia disorder: a theoretical review on the potential role of the orexinergic pathway with implications for insomnia treatment. J Sleep Res 2023:e13825. [PMID: 36786121 DOI: 10.1111/jsr.13825] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/31/2022] [Accepted: 01/01/2023] [Indexed: 02/15/2023]
Abstract
Insomnia disorder is considered as a stress-related disorder associated with hyperarousal, stress and emotion dysregulation and the instability of the 'flip-flop' switch system. The orexinergic system is well known for its key role in sleep and arousal processes but also in the allostatic system regulating stress and emotions and may thus be of major interest for insomnia and its treatment. Accordingly, we discuss the potential role of orexins on sleep processes, brain systems modulating stress and emotions with potential implications for insomnia pathophysiology. We reviewed available data on the effect of dual orexin receptor antagonists (DORAs) on sleep and brain systems modulating stress/emotions with implications for insomnia treatment. We present our findings as a narrative review. Few data in animals and humans have reported that disrupted sleep and insomnia may be related to the overactivation of orexinergic system, while some more consistent data in humans and animals reported the overactivation of orexins in response to acute stress and in stress-related disorders. Taken together these findings may let us hypothesise that an orexins overactivation may be associated with stress-related hyperarousal and the hyperactivation of arousal-promoting systems in insomnia. On the other hand, it is possible that by rebalancing orexins with DORAs we may regulate both sleep and allostatic systems, in turn, contributing to a 'switch off' of hyperarousal in insomnia. Nevertheless, more studies are needed to clarify the role of the orexin system in insomnia and to evaluate the effects of DORAs on sleep, stress and emotions regulating systems.
Collapse
Affiliation(s)
- Laura Palagini
- Department of Clinical and Experimental Medicine, Unit of Psychiatry, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy
| | - Pierre A Geoffroy
- Département de Psychiatrie et D'Addictologie, AP-HP, GHU Paris Nord, DMU Neurosciences, Hopital Bichat - Claude Bernard, Paris, France.,GHU Paris - Psychiatry and Neurosciences, Paris, France.,Université de Paris, NeuroDiderot, Inserm, Paris, France
| | - Matteo Balestrieri
- Unit of Psychiatry, Department of Medicine (DAME), University of Udine, Udine, Italy
| | - Mario Miniati
- Department of Clinical and Experimental Medicine, Unit of Psychiatry, Azienda Ospedaliero Universitaria Pisana AUOP, Pisa, Italy
| | - Giovanni Biggio
- Department of Life and Environmental Sciences, Institute of Neuroscience, University of Cagliari, National Research Council (C.N.R.), Cagliari, Italy
| | - Claudio Liguori
- Sleep Medicine Centre, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy.,Neurology Unit, Department of Systems Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Danilo Menicucci
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| | - Luigi Ferini-Strambi
- Department of Clinical Neurosciences, Neurology Sleep Disorders Centre, RCCS San Raffaele Scientific Institute, Milan, Italy
| | - Lino Nobili
- Sleep Medicine Center, Department of Neuroscience, Niguarda Hospital, Milan, Italy.,Department of Neuroscience (DINOGMI), University of Genoa, Child Neuropsychiatry Unit, IRCCS Istituto G. Gaslini, Genoa, Italy
| | - Dieter Riemann
- Department of Psychiatry and Psychotherapy, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Medicine, Center for Basics in NeuroModulation (NeuroModulBasics), University of Freiburg, Freiburg, Germany
| | - Angelo Gemignani
- Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, Pisa, Italy
| |
Collapse
|
8
|
Gołyszny M, Zieliński M, Paul-Samojedny M, Filipczyk Ł, Pałasz A, Obuchowicz E. Escitalopram alters the hypothalamic OX system but does not affect its up-regulation induced by early-life stress in adult rats. Neurosci Res 2022; 180:58-71. [PMID: 35219722 DOI: 10.1016/j.neures.2022.02.005] [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: 07/21/2021] [Revised: 02/07/2022] [Accepted: 02/23/2022] [Indexed: 01/06/2023]
Abstract
We hypothesized that there is a relationship between the orexinergic system (OX) alterations and changes elicited by escitalopram or venlafaxine in adult rats subjected to maternal separation (MS). This animal model of childhood adversity induces long-lasting consequences in adult physiology and behavior. Male Wistar rats from the control and MS groups were injected with escitalopram or venlafaxine (10 mg/kg) IP from postnatal day (PND) 69-89. Adult rats were subjected to behavioral assessment, estimation of hypothalamic-pituitary-adrenal (HPA) axis activity and analysis of the OX system (quantitative PCR and immunohistochemistry) in the hypothalamus and amygdala. MS caused anxiety- and depressive-like behavior, endocrine stress-related response, and up-regulation of the OX system in the hypothalamus. Escitalopram, but not venlafaxine, increased the activity of hypothalamic OX system in the control rats and both drugs had no effect on OXs in the MS group. The disturbed signaling of the OX pathway may be significant for harmful long-term consequences of early-life stress. Our data show that the normal brain and brain altered by MS respond differently to escitalopram. Presumably, anti-anxiety and antidepressant effects of this drug do not depend on the activity of hypothalamic OX system.
Collapse
Affiliation(s)
- Miłosz Gołyszny
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 street, Katowice 40-752, Poland.
| | - Michał Zieliński
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 street, Katowice 40-752, Poland
| | - Monika Paul-Samojedny
- Department of Medical Genetics, Faculty of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia, Jedności 8, Sosnowiec 41-200, Poland
| | - Łukasz Filipczyk
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 street, Katowice 40-752, Poland
| | - Artur Pałasz
- Department of Histology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 street, Katowice 40-752, Poland
| | - Ewa Obuchowicz
- Department of Pharmacology, Faculty of Medical Sciences in Katowice, Medical University of Silesia, Medyków 18 street, Katowice 40-752, Poland
| |
Collapse
|
9
|
Yaeger JDW, Krupp KT, Summers TR, Summers CH. Contextual generalization of social stress learning is modulated by orexin receptors in basolateral amygdala. Neuropharmacology 2022; 215:109168. [PMID: 35724928 PMCID: PMC9285878 DOI: 10.1016/j.neuropharm.2022.109168] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 01/22/2023]
Abstract
Fear-associated memories and behavior are often expressed in contexts/environments distinctively different from those in which they are created. This generalization process contributes to psychological disorders, particularly PTSD. Stress-related neurocircuits in the basolateral amygdala (BLA) receive inputs from hypothalamic orexin (Orx) neurons, which mediate neuronal activity by targeting orexin 1 (Orx1R) and orexin 2 (Orx2R) receptors via opposing functions. In BLA, inhibition of Orx1R or activation of Orx2R ameliorate stress responsiveness and behavior. We discovered that most Orx1R+ cells also express CamKIIα, while a majority of Orx2R+ cells are colocalized with GAD67. Further, Orx1R gene Hcrtr1 expression was positively correlated, and Orx2R gene Hcrtr2 expression was negatively correlated, with freezing in a phenotype-dependent fashion (Escape vs Stay) in the Stress Alternatives Model (SAM). The SAM consists of 4-days of social interaction between test mice and novel larger aggressors. Exits positioned at opposite ends of the SAM oval arena provide opportunities to actively avoid aggression. By Day 2, mice commit to behavioral phenotypes: Escape or Stay. Pharmacologically manipulating Orx receptor activity in the BLA, before Day 3 of the SAM, was followed with standard tests of anxiety: Open Field (OF) and Elevated Plus Maze (EPM). In Stay mice, freezing in response to social conflict and locomotion during SAM interaction (not home cage locomotion) were generalized to OF, and blocked by intra-BLA Orx1R antagonism, but not Orx2R antagonism. Moreover, patterns of social avoidance for Escape and Stay mice were recapitulated in OF, with generalization mediated by Orx1R and Orx2R antagonism, plus Orx2R stimulation.
Collapse
Affiliation(s)
- Jazmine D W Yaeger
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, 57105, USA; Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD, 57104, USA
| | - Kevin T Krupp
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA
| | - Tangi R Summers
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, 57105, USA
| | - Cliff H Summers
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, 57105, USA.
| |
Collapse
|
10
|
Flores-Ramirez FJ, Matzeu A, Sánchez-Marín L, Martin-Fardon R. Blockade of corticotropin-releasing factor-1 receptors in the infralimbic cortex prevents stress-induced reinstatement of alcohol seeking in male Wistar rats: Evidence of interaction between CRF 1 and orexin receptor signaling. Neuropharmacology 2022; 210:109046. [PMID: 35341789 PMCID: PMC9176217 DOI: 10.1016/j.neuropharm.2022.109046] [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: 10/06/2021] [Revised: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 10/18/2022]
Abstract
Alcohol use dysregulates responsivity to stress, which is mediated by corticotropin-releasing factor (CRF). With repeated cycles of alcohol use, the hypothalamic-pituitary-adrenal axis becomes hyporesponsive, rendering individuals vulnerable to the reinstatement of alcohol-seeking behavior during stressful episodes. Orexin (Orx; also called hypocretin) plays a well-established role in regulating diverse physiological processes, including stress, and interacts with CRF. The infralimbic cortex (IL) is a CRF-rich region. Anatomical evidence suggests that CRF and Orx interact in this area. To test the behavioral implication of CRF and Orx transmission in the IL during the stress-induced reinstatement of alcohol-seeking behavior, male Wistar rats were trained to self-administer 10% alcohol for 3 weeks. The rats then underwent two weeks of extinction training (identical to the alcohol self-administration sessions, but alcohol was withheld). The day after the last extinction session, the rats received a bilateral intra-IL injection of the CRF1 receptor antagonist CP154,526 (0.6 μg/0.5 μl/side), the dual Orx receptor antagonist TCS1102 (15 μg/0.5 μl/side), or their combination and then were tested for the footshock stress-induced reinstatement of alcohol-seeking behavior. CP154,526 significantly prevented reinstatement, but TCS1102 did not produce such an effect. Interestingly, the co-administration of TCS1102 and CP154,526 reversed the effect of CP154,526 alone, and footshock stress induced a significant increase in Crhr1 and Hcrtr2 mRNA expression in the IL. These results demonstrate a functional interaction between Orx receptor and CRF1 receptor signaling and suggest that CRF1 receptor antagonism may ameliorate stress-induced alcohol-seeking behavior.
Collapse
Affiliation(s)
| | - Alessandra Matzeu
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Laura Sánchez-Marín
- Unidad Gestión Clínica de Salud Mental, Instituto de Investigación Biomédica de Málaga, Hospital Regional Universitario de Málaga/Universidad de Málaga, Málaga, Spain
| | - Rémi Martin-Fardon
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA, USA
| |
Collapse
|
11
|
Abstract
SignificanceAnxiety disorders are among the most prevalent mental illnesses worldwide. Despite significant advances in their treatment, many patients remain treatment resistant. Thus, new treatment modalities and targets are much needed. Therefore, we developed a deep brain stimulation therapy that targets a recently identified anxiety center in the lateral hypothalamus. We show that this therapy rapidly silences anxiety-implicated neurons and immediately relieves diverse anxiety symptoms in a variety of stressful situations. This therapeutic effect occurs without acute or chronic side effects that are typical of many existing treatments, such as physical sedation or memory deficits. These findings identify a clinically applicable new therapeutic strategy for helping patients to manage treatment-resistant anxiety.
Collapse
|
12
|
Barretto-de-Souza L, Benini R, Reis-Silva LL, Crestani CC. Role of CRF 1 and CRF 2 receptors in the lateral hypothalamus in cardiovascular and anxiogenic responses evoked by restraint stress in rats: Evaluation of acute and chronic exposure. Neuropharmacology 2022; 212:109061. [PMID: 35452627 DOI: 10.1016/j.neuropharm.2022.109061] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 04/08/2022] [Accepted: 04/10/2022] [Indexed: 12/13/2022]
Abstract
We investigated the role of corticotropin-releasing factor (CRF) neurotransmission within the lateral hypothalamus (LH) in cardiovascular and anxiogenic-like responses evoked by acute and repeated restraint stress in rats. For this, animals were subjected to intra-LH microinjection of a selective CRF1 (CP376395) or CRF2 (antisauvagine-30) receptor antagonist before either an acute or the 10th session of restraint stress. Restraint-evoked arterial pressure and heart rate increases, tail skin temperature decrease and anxiogenic-like effect in the elevated plus maze (EPM) were evaluated. We also assessed the effect of 10 daily sessions of restraint on expression of CRF1 and CRF2 receptors within the LH. We identified that antagonism of either CRF1 or CRF2 receptor within the LH decreased the tachycardia during both the acute and 10th session of restraint, but the effect of the CRF1 receptor antagonist was more pronounced during the 10th session. Acute restraint stress also caused anxiogenic-like effect, and this response was inhibited in animals treated with either CP376395 or antisauvagine-30. Anxiety-like behaviors were not changed following the 10th session of restraint, and pharmacological treatments did not affect the behavior in the EPM in chronically stressed animals. Repeated restraint also did not change the level of the CRF receptors within the LH. Taken together, the findings indicate that CRF1 and CRF2 receptors within the LH are involved in tachycardic and anxiogenic-like responses to aversive stimuli. Control of tachycardia by the CRF1 receptor is sensitized by previous stressful experience, and this effect seems to be independent of changes in expression of the receptor.
Collapse
Affiliation(s)
- Lucas Barretto-de-Souza
- Laboratory of Pharmacology, São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, SP, Brazil
| | - Ricardo Benini
- Laboratory of Pharmacology, São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, SP, Brazil
| | - Lilian Liz Reis-Silva
- Laboratory of Pharmacology, São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, SP, Brazil
| | - Carlos C Crestani
- Laboratory of Pharmacology, São Paulo State University (UNESP), School of Pharmaceutical Sciences, Araraquara, SP, Brazil.
| |
Collapse
|
13
|
Peleg-Raibstein D, Burdakov D. Do orexin/hypocretin neurons signal stress or reward? Peptides 2021; 145:170629. [PMID: 34416308 DOI: 10.1016/j.peptides.2021.170629] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/04/2021] [Accepted: 08/14/2021] [Indexed: 12/23/2022]
Abstract
Hypothalamic neurons that produce the peptide transmitters orexins/hypocretins (HONs) broadcast their predominantly neuroexcitatory outputs to the entire brain via their extremely wide axonal projections. HONs were originally reported to be activated by food deprivation, and to stimulate arousal, energy expenditure, and eating. This led to extensive studies of HONs in the context of nutrient-sensing and energy balance control. While activation of HONs by body energy depletion continues to be supported by experimental evidence, it has also become clear that HONs are robustly activated not only by nutrient depletion, but also by diverse sensory stimuli (both neutral and those associated with rewarding or aversive events), seemingly unrelated to each other or to energy balance. One theory that could unify these findings is that all these stimuli signal "stress" - defined either as a potentially harmful state, or an awareness of reward deficiency. If HON activity is conceptualized as a cumulative representation of stress, then many of the reported HONs outputs - including EEG arousal, sympathetic activation, place avoidance, and exploratory behaviours - could be viewed as logical stress-counteracting responses. We discuss evidence for and against this unifying theory of HON function, including the alterations in HON activity observed in anxiety and depression disorders. We propose that, in order to orchestrate stress-countering responses, HONs need to coactivate motivation and aversion brain systems, and the impact of HON stimulation on affective states may be perceived as rewarding or aversive depending on the baseline HON activity.
Collapse
Affiliation(s)
| | - Denis Burdakov
- Department of Health Sciences and Technology, ETH Zürich, Switzerland.
| |
Collapse
|
14
|
Li B, Chang L, Peng X. Orexin 2 receptor in the nucleus accumbens is critical for the modulation of acute stress-induced anxiety. Psychoneuroendocrinology 2021; 131:105317. [PMID: 34111776 DOI: 10.1016/j.psyneuen.2021.105317] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 06/02/2021] [Accepted: 06/02/2021] [Indexed: 11/30/2022]
Abstract
Orexin is a neuropeptide mainly synthesized in the lateral hypothalamus/perifornical area and has been traditionally implicated in feeding, sleep-wake cycles, and reward. Intriguingly, patients with anxiety have increased levels of orexin in the cerebrospinal fluid. Pharmacological or genetic manipulation of orexin receptors affects anxiety-like behaviors in rodents, suggesting an involvement of the orexin signaling in the regulation of anxiety. Yet, the neural substrates involved remain largely unknown. The nucleus accumbens (NAc) shell holds a key position in the modulation of anxiety-related behaviors. Therefore, in the present study, by using neuropharmacology, molecular approaches and behavioral tests in rats, the role of orexin/orexin receptors in the NAc shell on the anxiety-like behaviors was investigated. We found that microinjection of orexin-A into the NAc shell induced an anxiogenic-like effect. Quantitative real-time PCR and immunofluorescence showed that the orexin 2 receptor (OX2R) is expressed and distributed in the NAc shell neurons. Activation of OX2R mimicked the anxiogenic effect of orexin-A. Moreover, infusion of an OX2R antagonist had no effect on anxiety-like behaviors in normal rats, but reversed anxiogenic effect induced by acute restraint stress. Finally, we found that downregulation of OX2R in the NAc shell caused an anxiolytic-like effect in acute restraint stressed rats, which was consistent with the pharmacological results. Together, this study suggests that OX2R in the NAc shell is involved in the regulation of acute stress-induced anxiety, and raises the possibility that OX2R antagonist may serve as an effective mean to treat anxiety disorders.
Collapse
Affiliation(s)
- Bin Li
- Women & Children Central Laboratory, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Leilei Chang
- Department of Neurology, Affiliated Drum Tower Hospital, Nanjing University Medical School, Nanjing, China
| | - Xiaochun Peng
- School of Life Sciences, Nanjing University, Nanjing, China
| |
Collapse
|
15
|
Han D, Shi Y, Han F. The effects of orexin-A and orexin receptors on anxiety- and depression-related behaviors in a male rat model of post-traumatic stress disorder. J Comp Neurol 2021; 530:592-606. [PMID: 34387361 DOI: 10.1002/cne.25231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022]
Abstract
Orexin neurons play an important role in stress-related mental disorders including post-traumatic stress disorder (PTSD). Anxiety- and depression-related symptoms commonly occur in combination with PTSD. However, the role of the orexin system in mediating alterations in these affective symptoms remains unclear. The medial prefrontal cortex (mPFC) is implicated in both cognitive and emotional processing. In the present study, we investigated anxiety- and depression-related behavioral changes using the elevated plus maze, the sucrose preference test, and the open field test in male rats with single prolonged stress (SPS) induced-PTSD. The expression of orexin-A in the hypothalamus and orexin receptors (OX1R and OX2R) in the mPFC was detected and quantified by immunohistochemistry, western blotting, and real-time polymerase chain reaction. We found that the SPS rats exhibited enhanced levels of anxiety, reduced exploratory activities, and anhedonia. Furthermore, SPS resulted in reductions in the expression of orexin-A in the hypothalamus and the increased the expression of OX1R in the mPFC. The intracerebroventricular administration of orexin-A alleviated behavioral changes in SPS rats and partly restored the increased levels of OX1R in the mPFC. These results suggest that the orexin system plays a role in the anxiety- and depression-related symptoms observed in PTSD.
Collapse
Affiliation(s)
- Dan Han
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, Shenyang, China.,Department of Neonatology, The First Hospital of China Medical University, Shenyang, China
| | - Yuxiu Shi
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, Shenyang, China
| | - Fang Han
- PTSD Laboratory, Department of Histology and Embryology, Basic Medical Sciences College, China Medical University, Shenyang, China
| |
Collapse
|
16
|
Olsen N, Furlong TM, Carrive P. Behavioural and cardiovascular effects of orexin-A infused into the central amygdala under basal and fear conditions in rats. Behav Brain Res 2021; 415:113515. [PMID: 34371088 DOI: 10.1016/j.bbr.2021.113515] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 07/16/2021] [Accepted: 08/03/2021] [Indexed: 10/20/2022]
Abstract
The neuropeptide orexin-A (OX-A) has diverse functions, including maintaining arousal, autonomic control, motor activity and stress responses. These functions are regulated at different terminal regions where OX-A is released. The current study examined the physiological and behavioural effects of OX-A microinjections into the central amygdala (CeA) under basal and stressed conditions in rats. When OX-A was microinjected into the CeA and the animals returned to the home-cage, heart rate and mean arterial pressure were increased compared to vehicle-injected controls. General activity of the animal was also increased, indicating that OX-A activity in CeA contributes to increased arousal. This outcome is similar to the effects of central intracerebroventricular infusions of OX-A, as well as the cardiovascular effects previously demonstrated at many of OX's efferent hypothalamic and brainstem structures. In a second study, animals were fear-conditioned to a context by delivery of electric footshocks and then animals were re-exposed to the conditioned context at test. When OX-A was microinjected at test, freezing behaviour was reduced and there was a corresponding increase in the animal's activity but no impact on the pressor and cardiac responses (i.e, blood pressure and heart rate were unchanged). This reduction in freezing suggests that OX-A activates amygdala neurons that inhibit freezing, which is similar to the actions of other neuropeptides in the CeA that modulate the appropriate defence response to fearful stimuli. Overall, these data indicate that the CeA is an important site of OX-A modulation of cardiovascular and motor activity, as well as conditioned freezing responses.
Collapse
Affiliation(s)
- Nick Olsen
- School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Teri M Furlong
- School of Medical Sciences, The University of New South Wales, Sydney, Australia; Neuroscience Research Australia, Randwick, Australia.
| | - Pascal Carrive
- School of Medical Sciences, The University of New South Wales, Sydney, Australia
| |
Collapse
|
17
|
Pang TY, Yaeger JDW, Summers CH, Mitra R. Cardinal role of the environment in stress induced changes across life stages and generations. Neurosci Biobehav Rev 2021; 124:137-150. [PMID: 33549740 PMCID: PMC9286069 DOI: 10.1016/j.neubiorev.2021.01.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 11/20/2020] [Accepted: 01/08/2021] [Indexed: 12/21/2022]
Abstract
The stress response in rodents and humans is exquisitely dependent on the environmental context. The interactive element of the environment is typically studied by creating laboratory models of stress-induced plasticity manifested in behavior or the underlying neuroendocrine mediators of the behavior. Here, we discuss three representative sets of studies where the role of the environment in mediating stress sensitivity or stress resilience is considered across varying windows of time. Collectively, these studies testify that environmental variation at an earlier time point modifies the relationship between stressor and stress response at a later stage. The metaplastic effects of the environment on the stress response remain possible across various endpoints, including behavior, neuroendocrine regulation, region-specific neural plasticity, and regulation of receptors. The timescale of such variation spans adulthood, across stages of life history and generational boundaries. Thus, environmental variables are powerful determinants of the observed diversity in stress response. The predominant role of the environment suggests that it is possible to promote stress resilience through purposeful modification of the environment.
Collapse
Affiliation(s)
- Terence Y Pang
- Florey Institute of Neuroscience and Mental Health, Parkville, 3052, VIC, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, 3010, VIC, Australia
| | - Jazmine D W Yaeger
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, 57105, USA
| | - Cliff H Summers
- Department of Biology, University of South Dakota, Vermillion, SD, 57069, USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, 57069, USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, 57105, USA
| | - Rupshi Mitra
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore.
| |
Collapse
|
18
|
Gupta PR, Prabhavalkar K. Combination therapy with neuropeptides for the treatment of anxiety disorder. Neuropeptides 2021; 86:102127. [PMID: 33607407 DOI: 10.1016/j.npep.2021.102127] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 12/29/2020] [Accepted: 01/26/2021] [Indexed: 11/29/2022]
Abstract
Anxiety is a neurological disorder that is characterized by excessive, persistent, and unreasonable worry about everyday things like family, work, money, and relationships. The current therapy used for the treatment has many disadvantages like higher cost, severe adverse reactions, and has suboptimal efficiency. There is a need to look for more innovative approaches for the treatment of anxiety disorder which overcomes the disadvantages of conventional treatment. Recent findings suggest a strong correlation of glutamate with anxiety. Some promising drugs which have a novel mechanism for anxiolytic action are currently under clinical development for generalized anxiety disorder, social anxiety disorder, panic disorder, obsessive-compulsive disorder, or post-traumatic stress disorder. Similarly, an interrelation of oxytocin with neuropeptide S or glutamate or vasopressin can also be considered for further evaluation for the development of new drugs for anxiety treatment. Anxiolytic drug development is a multi-target approach, with the idea of more efficiently equilibrating perturbed circuits. This review focuses on targeting unconventional targets like the glutamate system, voltage-gated ion channels, and neuropeptides system either alone or in combination for the treatment of anxiety disorder.
Collapse
Affiliation(s)
- Priti Ramakant Gupta
- Department of Pharmacology, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Mumbai 400 056, India
| | - Kedar Prabhavalkar
- Department of Pharmacology, SVKM'S Dr. Bhanuben Nanavati College of Pharmacy, Mumbai 400 056, India.
| |
Collapse
|
19
|
Okumura T, Ishioh M, Nozu T. Central regulatory mechanisms of visceral sensation in response to colonic distension with special reference to brain orexin. Neuropeptides 2021; 86:102129. [PMID: 33636498 DOI: 10.1016/j.npep.2021.102129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 01/08/2021] [Accepted: 02/09/2021] [Indexed: 01/22/2023]
Abstract
Visceral hypersensitivity is a major pathophysiology in irritable bowel syndrome (IBS). Although brain-gut interaction is considered to be involved in the regulation of visceral sensation, little had been known how brain controls visceral sensation. To improve therapeutic strategy in IBS, we should develop a novel approach to control visceral hypersensitivity. Here, we summarized recent data on central control of visceral sensation by neuropeptides in rats. Orexin, ghrelin or oxytocin in the brain is capable of inducing visceral antinociception. Dopamine, cannabinoid, adenosine, serotonin or opioid in the central nervous system (CNS) plays a role in the visceral hyposensitivity. Central ghrelin, levodopa or morphine could induce visceral antinociception via the orexinergic signaling. Orexin induces visceral antinociception through dopamine, cannabinoid, adenosine or oxytocin. Orexin nerve fibers are identified widely throughout the CNS and orexins are implicated in a number of functions. With regard to gastrointestinal functions, in addition to its visceral antinociception, orexin acts centrally to stimulate gastrointestinal motility and improve intestinal barrier function. Brain orexin is also involved in regulation of sleep/awake cycle and anti-depressive action. From these evidence, we would like to make a hypothesis that decreased orexin signaling in the brain may play a role in the pathophysiology in a part of patients with IBS who are frequently accompanied with sleep disturbance, depressive state and disturbed gut functions such as gut motility disturbance, leaky gut and visceral hypersensitivity.
Collapse
Affiliation(s)
- Toshikatsu Okumura
- Division of Metabolism, Biosystemic Science, Gastroenterology and Hematology/Oncology, Department of Medicine, Japan.
| | - Masatomo Ishioh
- Division of Metabolism, Biosystemic Science, Gastroenterology and Hematology/Oncology, Department of Medicine, Japan
| | - Tsukasa Nozu
- Department of Regional Medicine and Education, Asahikawa Medical University, Japan
| |
Collapse
|
20
|
Kirouac GJ. The Paraventricular Nucleus of the Thalamus as an Integrating and Relay Node in the Brain Anxiety Network. Front Behav Neurosci 2021; 15:627633. [PMID: 33732118 PMCID: PMC7959748 DOI: 10.3389/fnbeh.2021.627633] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/28/2021] [Indexed: 12/25/2022] Open
Abstract
The brain anxiety network is composed of a number of interconnected cortical regions that detect threats and execute appropriate defensive responses via projections to the shell of the nucleus accumbens (NAcSh), dorsolateral region of the bed nucleus of the stria terminalis (BSTDL) and lateral region of the central nucleus of the amygdala (CeL). The paraventricular nucleus of the thalamus (PVT) is anatomically positioned to integrate threat- and arousal-related signals from cortex and hypothalamus and then relay these signals to neural circuits in the NAcSh, BSTDL, and CeL that mediate defensive responses. This review describes the anatomical connections of the PVT that support the view that the PVT may be a critical node in the brain anxiety network. Experimental findings are reviewed showing that the arousal peptides orexins (hypocretins) act at the PVT to promote avoidance of potential threats especially following exposure of rats to a single episode of footshocks. Recent anatomical and experimental findings are discussed which show that neurons in the PVT provide divergent projections to subcortical regions that mediate defensive behaviors and that the projection to the NAcSh is critical for the enhanced social avoidance displayed in rats exposed to footshocks. A theoretical model is proposed for how the PVT integrates cortical and hypothalamic signals to modulate the behavioral responses associated with anxiety and other challenging situations.
Collapse
Affiliation(s)
- Gilbert J. Kirouac
- Department of Oral Biology, Dr. Gerald Niznick College of Dentistry, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| |
Collapse
|
21
|
Harris T, Bugescu R, Kelly J, Makela A, Sotzen M, Sisk C, Atkin G, Pratt R, Crockett E, Leinninger G. DLK1 Expressed in Mouse Orexin Neurons Modulates Anxio-Depressive Behavior but Not Energy Balance. Brain Sci 2020; 10:brainsci10120975. [PMID: 33322758 PMCID: PMC7764426 DOI: 10.3390/brainsci10120975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 11/16/2022] Open
Abstract
Lateral hypothalamic area (LHA) neurons expressing the neuropeptide orexin (OX) are implicated in obesity and anxio-depression. However, these neurons release OX as well as a host of other proteins that might contribute to normal physiology and disease states. We hypothesized that delta-like homolog 1 (DLK1), a protein reported to be co-expressed by all OX neurons, contributes to the regulation of energy balance and/or anxio-depression. Consistent with previous reports, we found that all rat OX neurons co-express DLK1. Yet, in mice and humans only a subset of OX neurons co-expressed DLK1. Since human OX-DLK1 distribution is more similar to mice than rats, mice are a comparable model to assess the human physiologic role of DLK1. We therefore used a viral lesion strategy to selectively delete DLK1 within the LHA of adult mice (DLK1Null) to reveal its role in body weight and behavior. Adult-onset DLK1 deletion had no impact on body weight or ingestive behavior. However, DLK1Null mice engaged in more locomotor activity than control mice and had decreased anxiety and depression measured via the elevated plus maze and forced swim tests. These data suggest that DLK1 expression via DLK1-expressing OX neurons primarily contributes to anxio-depression behaviors without impacting body weight.
Collapse
Affiliation(s)
- Tatiyana Harris
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Jaylyn Kelly
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Anna Makela
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Morgan Sotzen
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Cheryl Sisk
- Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI 48824, USA;
| | - Graham Atkin
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA;
| | - Rebecca Pratt
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA;
| | - Elahé Crockett
- Department of Medicine, Michigan State University, East Lansing, MI 48824, USA;
| | - Gina Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
- Correspondence:
| |
Collapse
|
22
|
Abstract
Twenty-two years after their discovery, the hypocretins (Hcrts), also known as orexins, are two of the most studied peptidergic systems, involved in myriad physiological systems that range from sleep, arousal, motivation, homeostatic regulation, fear, anxiety and learning. A causal relationship between activity of Hcrt and arousal stability was established shortly after their discovery and have led to the development of a new class of drugs to treat insomnia. In this review we discuss the many faces of the Hcrt system and examine recent findings that implicate decreased Hcrt function in the pathogenesis of a number of neuropsychiatric conditions. We also discuss future therapeutic strategies to replace or enhance Hcrt function as a treatment option for these neuropsychiatric conditions.
Collapse
Affiliation(s)
- Erica Seigneur
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA
| |
Collapse
|
23
|
Yaeger JD, Krupp KT, Gale JJ, Summers CH. Counterbalanced microcircuits for Orx1 and Orx2 regulation of stress reactivity. MEDICINE IN DRUG DISCOVERY 2020. [DOI: 10.1016/j.medidd.2020.100059] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
|
24
|
Burdakov D, Peleg-Raibstein D. The hypothalamus as a primary coordinator of memory updating. Physiol Behav 2020; 223:112988. [DOI: 10.1016/j.physbeh.2020.112988] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/05/2020] [Accepted: 05/26/2020] [Indexed: 12/19/2022]
|
25
|
Zhang W. Neural Circuits for Reward. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1284:35-41. [PMID: 32852738 DOI: 10.1007/978-981-15-7086-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Innate behaviors often viewed as genetically predetermined behaviors. However, in the environment animals often are subjected to external stimuli conflicting with those. Thus, animals subsequently need to change those behaviors to survive and reproduce. In the brain, the reward pathway is well-known for its role to adjust behaviors according to external stimuli, or rewards. However, only recently the relationship between reward pathway and innate behavior begins to be explored. In this review, we summarize the recent data on this subject from rodent studies which suggest an important role of this crosstalk between circuits involved in reward pathway and innate behaviors. We also discuss some of the neurotransmitters and neuromodulators underlying this crosstalk and the related mechanisms.
Collapse
Affiliation(s)
- Wen Zhang
- National Institute on Drug Dependence, Peking University, Beijing, China.
| |
Collapse
|
26
|
Garau C, Blomeley C, Burdakov D. Orexin neurons and inhibitory Agrp→orexin circuits guide spatial exploration in mice. J Physiol 2020; 598:4371-4383. [PMID: 32667686 DOI: 10.1113/jp280158] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/13/2020] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS Photoinhibition of endogenous activity of lateral hypothalamic orexin neurons causes place preference and reduces innate avoidance Endogenous activity of orexin neurons correlates with place preference Mediobasal hypothalamic Agrp neurons inhibit orexin neurons via GABA, and chemogenetic suppression of Agrp neurons increases avoidance in an orexin receptor-dependent manner. ABSTRACT Hypothalamic orexin/hypocretin neurons integrate multiple sensory cues and project brain-wide to orchestrate diverse innate behaviours. Their loss impairs many context-appropriate actions, but the motivational characteristics of orexin cell activity remain unclear. We and others previously approached this question by artificial orexin stimulation, which could induce either rewarding (positive valence) or aversive (negative valence) brain activity. It is unknown to what extent such approaches replicate natural/endogenous orexin signals, which rapidly fluctuate during wakefulness. Here we took an alternative approach, focusing on observing and silencing natural orexin cell signals associated with a fundamental innate behaviour, self-paced spatial exploration. We found that mice are more likely to stay in places paired with orexin cell optosilencing. The orexin cell optosilencing also reduced avoidance of places that mice find innately aversive. Correspondingly, calcium recordings revealed that orexin cell activity rapidly reduced upon exiting the innately aversive places. Furthermore, we provide optogenetic evidence for an inhibitory GABAergic Agrp→orexin hypothalamic neurocircuit, and find that Agrp cell suppression increases innate avoidance behaviour, consistent with orexin disinhibition. These results imply that exploration may be motivated and oriented by a need to reduce aversive orexin cell activity, and suggest a hypothalamic circuit for fine-tuning orexin signals to changing ethological priorities.
Collapse
Affiliation(s)
- Celia Garau
- The Francis Crick Institute, London, NW1 1AT, UK
| | | | | |
Collapse
|
27
|
Abstract
Objectives: The relationships between orexins and stress-related conditions have been well documented in animal studies. However, human studies confirming this relationship are limited. The aim of this study was to investigate the association between orexin-A and anxiety disorders in adolescents. Additionally, we aimed to examine the relationship between orexin-A and cortisol levels in those with anxiety disorders.Methods: A total of 56 medication-free adolescents diagnosed with any anxiety disorder, except for specific phobias, and 32 healthy controls were included in this study. Depression, state and trait anxiety levels of the participants were measured using self-report scales. Orexin-A and cortisol levels were measured by an enzyme-linked immunosorbent assay (ELISA).Results: Analysis of covariance (ANCOVA) indicated that serum orexin-A levels were significantly higher in the anxiety disorder group than in the control group while controlling for age, sex and depression levels. After controlling for age and sex, orexin-A levels were positively and negatively correlated to depression and cortisol levels, respectively. In addition, a positive correlation trend between trait anxiety and orexin-A was found.Conclusions: Orexin-A levels are higher in adolescents with anxiety disorder; however, depressive symptoms should be considered when investigating this relationship.
Collapse
Affiliation(s)
- Ömer Faruk Akça
- Department of Child and Adolescent Psychiatry, Necmettin Erbakan University Meram School of Medicine, Konya, Turkey
| | - Necati Uzun
- Department of Child and Adolescent Psychiatry, Dr. Ali Kemal Belviranlı Children Hospital, Konya, Turkey
| | - İbrahim Kılınç
- Department of Biochemistry, Necmettin Erbakan University Meram School of Medicine, Konya, Turkey
| |
Collapse
|
28
|
Shahsavari F, Abbasnejad M, Raoof M, Esmaeili-Mahani S. The rostral ventromedial medulla orexin 1 receptors and extracellular signal-regulated kinase in hippocampus are involved in modulation of anxiety behavior induced by dental pulp nociception in adult male rats. Arch Oral Biol 2020; 116:104778. [PMID: 32474210 DOI: 10.1016/j.archoralbio.2020.104778] [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: 02/25/2020] [Revised: 05/21/2020] [Accepted: 05/21/2020] [Indexed: 11/16/2022]
Abstract
OBJECTIVES To explore the role of rostral ventromedial medulla (RVM) orexin 1 receptors (OX1R) on orofacial nociception -induced anxiety and locomotion in rats. DESIGN Forty two adult male Wistar rats (220-270 gr) were randomly divided into 7 groups (n = 6) as follows: untreated control, capsaicin, capsaicin vehicle-treated group (sham operation), capsaicin groups pretreated by intra-RVM administration orexin 1 receptor (OX1R) agonist (orexin A) or antagonist (SB-334867) and the capsaicin groups treated by drugs vehicles (DMSO or aCSF). Orofacial nociception was induced by intradental application of capsaicin (100 μg) into the incisors of rats. Anxiety level and locomotor activity were measured by the elevated plus maze (EPM) and open field (OF) tests, respectively. Hippocampal levels of phosphorylated extracellular signal regulated Kinase (p-ERK) was also assessed by western blotting. RESULTS Intradental application of capsaicin significantly increased anxiety and decreased locomotion behaviors. Intra-RVM microinjection of orexin-A significantly prevented capsaicin-induced anxiety-like behavior and increased locomotor activity in the EPM and OF tests. These effects were inhibited by SB-334867. Furthermore, orexin-A significantly increased p-ERK levels in capsaicin-treated rats. This effect was inhibited by pretreatment of the rats with SB-334867. CONCLUSIONS The results suggest that both OX1R signaling in the RVM and hippocampal p-ERK signaling are involved in orofacial nociception-induced anxiety as well as locomotor activity.
Collapse
Affiliation(s)
- Fatemeh Shahsavari
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran.
| | - Maryam Raoof
- Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran; Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Saeed Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University, Kerman, Iran; Neuroscience Research Center, Kerman University of Medical Sciences, Kerman, Iran
| |
Collapse
|
29
|
Salehabadi S, Abrari K, Elahdadi Salmani M, Nasiri M, Lashkarbolouki T. Investigating the role of the amygdala orexin receptor 1 in memory acquisition and extinction in a rat model of PTSD. Behav Brain Res 2020; 384:112455. [DOI: 10.1016/j.bbr.2019.112455] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/17/2019] [Accepted: 12/26/2019] [Indexed: 11/15/2022]
|
30
|
Pan YP, Liu C, Liu MF, Wang Y, Bian K, Xue Y, Chen L. Involvement of orexin-A in the regulation of neuronal activity and emotional behaviors in central amygdala in rats. Neuropeptides 2020; 80:102019. [PMID: 31980205 DOI: 10.1016/j.npep.2020.102019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 01/14/2020] [Accepted: 01/15/2020] [Indexed: 12/11/2022]
Abstract
The amygdala is a complex structure involved in the regulation of emotional behaviors including fear and anxiety. The central amygdala is the main output of the amygdala and plays an important role in emotional processing. Recent studies indicate that orexin, a kind of neuropeptides responsible for maintaining wakefulness, is also associated with emotion-related behaviors, such as depression- and anxiety-like behaviors. Central amygdala receives orexinergic fibers originating from the lateral hypothalamus and expresses OX1 receptors in rats. To test the electrophysiological and behavioral effects of orexins in the central amygdala, single unit in vivo extracellular recordings, open field and elevated plus maze tests were performed in rats. Micro-pressure administration of orexin-A (0.01 mmol/L) increased the firing rate in 18 out of the 31 central amygdala neurons, while the other 13 neurons were not excited by orexin-A. The excitatory effects of orexin-A on central amygdala neurons were mainly mediated by OX1 receptors rather than OX2 receptors. Orexin-B (0.01 mmol/L) did not change the firing activity in all recorded central amygdala neurons. Selectively blocking OX1 receptors by SB-334867 (0.01 mmol/L) significantly decreased the spontaneous firing rate in 14 out of the 33 central amygdala neurons, leaving the remaining 19 neurons were not affected. However, blocking OX2 receptors by TCS-OX2-29 (0.01 mmol/L) did not change the firing activity. Finally, both open field test and elevated plus maze test showed that bilateral microinjection of orexin-A into the central amygdala induced significantly anxiolytic-like behaviors. The specific OX1 receptor antagonist tended to produce opposite effects although there was no statistical difference. The present electrophysiological and behavioral studies suggested that orexin-A participates in anxiety-like behaviors by modulating the spontaneous firing activity of central amygdala neurons.
Collapse
Affiliation(s)
- Yi-Peng Pan
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Cui Liu
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Mei-Fang Liu
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Ying Wang
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Kang Bian
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yan Xue
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China
| | - Lei Chen
- Department of Physiology, School of Basic Medicine, Qingdao University, Qingdao, China.
| |
Collapse
|
31
|
Kim JS, Martin-Fardon R. Possible Role of CRF-Hcrt Interaction in the Infralimbic Cortex in the Emergence and Maintenance of Compulsive Alcohol-Seeking Behavior. Alcohol Clin Exp Res 2020; 44:354-367. [PMID: 31840823 PMCID: PMC7018591 DOI: 10.1111/acer.14264] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 11/28/2019] [Indexed: 12/19/2022]
Abstract
Alcohol use disorder (AUD) is a chronic, relapsing disorder that is characterized by the compulsive use of alcohol despite numerous health, social, and economic consequences. Initially, the use of alcohol is driven by positive reinforcement. Over time, however, alcohol use can take on a compulsive quality that is driven by the desire to avoid the negative consequences of abstinence, including negative affect and heightened stress/anxiety. This transition from positive reinforcement- to negative reinforcement-driven consumption involves the corticotropin-releasing factor (CRF) system, although mounting evidence now suggests that the CRF system interacts with other neural systems to ultimately produce behaviors that are symptomatic of compulsive alcohol use, such as the hypocretin (Hcrt) system. Hypocretins are produced exclusively in the hypothalamus, but Hcrt neurons project widely throughout the brain and reach regions that perform regulatory functions for numerous behavioral and physiological responses-including the infralimbic cortex (IL) of the medial prefrontal cortex (mPFC). Although the entire mPFC undergoes neuroadaptive changes following prolonged alcohol exposure, the IL appears to undergo more robust changes compared with other mPFC substructures. Evidence to date suggests that the IL is likely involved in EtOH-seeking behavior, but ambiguities with respect to the specific role of the IL in this regard make it difficult to draw definitive conclusions. Furthermore, the manner in which CRF interacts with Hcrt in this region as it pertains to alcohol-seeking behavior is largely unknown, although immunohistochemical and electrophysiological experiments have shown that CRF and Hcrt directly interact in the mPFC, suggesting that the interaction between CRF and Hcrt in the IL may be critically important for the development and subsequent maintenance of compulsive alcohol seeking. This review aims to consolidate recent literature regarding the role of the IL in alcohol-seeking behavior and to discuss evidence that supports a functional interaction between Hcrt and CRF in the IL.
Collapse
Affiliation(s)
- Jung S. Kim
- Department of Molecular Medicine, Scripps Research, La Jolla, USA
| | | |
Collapse
|
32
|
Collier AD, Min SS, Campbell SD, Roberts MY, Camidge K, Leibowitz SF. Maternal ethanol consumption before paternal fertilization: Stimulation of hypocretin neurogenesis and ethanol intake in zebrafish offspring. Prog Neuropsychopharmacol Biol Psychiatry 2020; 96:109728. [PMID: 31394141 PMCID: PMC6815720 DOI: 10.1016/j.pnpbp.2019.109728] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 08/02/2019] [Accepted: 08/03/2019] [Indexed: 12/27/2022]
Abstract
There are numerous clinical and pre-clinical studies showing that exposure of the embryo to ethanol markedly affects neuronal development and stimulates alcohol drinking and related behaviors. In rodents and zebrafish, our studies show that embryonic exposure to low-dose ethanol, in addition to increasing voluntary ethanol intake during adolescence, increases the density of hypothalamic hypocretin (hcrt) neurons, a neuropeptide known to regulate reward-related behaviors. The question addressed here in zebrafish is whether maternal ethanol intake before conception also affects neuronal and behavioral development, phenomena suggested by clinical reports but seldom investigated. To determine if preconception maternal ethanol consumption also affects these hcrt neurons and behavior in the offspring, we first standardized a method of measuring voluntary ethanol consumption in AB strain adult and larval zebrafish given gelatin meals containing 10% or 0.1% ethanol, respectively. We found the number of bites of gelatin to be an accurate measure of intake in adults and a strong predictor of blood ethanol levels, and also to be a reliable indicator of intake in larval zebrafish. We then used this feeding paradigm and live imaging to examine the effects of preconception maternal intake of 10% ethanol-gelatin compared to plain-gelatin for 14 days on neuronal development in the offspring. Whereas ethanol consumption by adult female HuC:GFP transgenic zebrafish had no impact on the number of differentiated HuC+ neurons at 28 h post-fertilization (hpf), preconception ethanol consumption by adult female hcrt:EGFP zebrafish significantly increased the number of hcrt neurons in the offspring, an effect observed at 28 hpf and confirmed at 6 and 12 days post-fertilization (dpf). This increase in hcrt neurons was primarily present on the left side of the brain, indicating asymmetry in ethanol's actions, and it was accompanied by behavioral changes in the offspring, including a significant increase in novelty-induced locomotor activity but not thigmotaxis measured at 6 dpf and also in voluntary consumption of 0.1% ethanol-gelatin at 12 dpf. Notably, these measures of ethanol intake and locomotor activity stimulated by preconception ethanol were strongly, positively correlated with the number of hcrt neurons. These findings demonstrate that preconception maternal ethanol consumption affects the brain and behavior of the offspring, producing effects similar to those caused by embryonic ethanol exposure, and they provide further evidence that the ethanol-induced increase in hcrt neurogenesis contributes to the behavioral disturbances caused by ethanol.
Collapse
Affiliation(s)
- Adam D Collier
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA
| | - Soe S Min
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA
| | - Samantha D Campbell
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA
| | - Mia Y Roberts
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA
| | - Kaylin Camidge
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA
| | - Sarah F Leibowitz
- Laboratory of Behavioral Neurobiology, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
33
|
Dhangar RR, Kale PP, Kadu PK, Prabhavalkar K. Possible Benefits of Considering Glutamate with Melatonin or Orexin or Oxytocin as a Combination Approach in the Treatment of Anxiety. ACTA ACUST UNITED AC 2019. [DOI: 10.1007/s40495-019-00207-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
34
|
Intra-accumbal orexin-1 receptor inhibition prevents the anxiolytic-like effect of ethanol and leads to increases in orexin-A content and receptor expression. Pharmacol Biochem Behav 2019; 185:172761. [DOI: 10.1016/j.pbb.2019.172761] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/23/2022]
|
35
|
Orexin-A promotes EEG changes but fails to induce anxiety in rats. Behav Brain Res 2019; 361:26-31. [DOI: 10.1016/j.bbr.2018.12.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/03/2018] [Accepted: 12/20/2018] [Indexed: 11/19/2022]
|
36
|
Li G, Zhang K, Wang L, Cao C, Fang R, Liu P, Luo S, Liberzon I. The preliminary investigation of orexigenic hormone gene polymorphisms on posttraumatic stress disorder symptoms. Psychoneuroendocrinology 2019; 100:131-136. [PMID: 30326460 DOI: 10.1016/j.psyneuen.2018.09.042] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/18/2018] [Accepted: 09/30/2018] [Indexed: 12/12/2022]
Abstract
Orexigenic hormones are a group of hormones that can up-regulate appetite. Current studies have shown that orexigenic hormones also play important roles in stress responses and may be implicated in regulation of fear memory. However, these conclusions lack evidence from human studies. In this study, we examined associations between orexigenic hormone genes and fear-related mental disorders by investigating main, G × E, and G × G effects of ghrelin and orexin gene single nucleotide polymorphisms (SNPs) on human posttraumatic stress disorder (PTSD) symptoms in 1134 Chinese earthquake survivors. SNPs Leu72Met of the GHRL gene (rs696217), Ile408Val of the HCRTR1 gene (rs2271933) and Val308Ile of the HCRTR2 gene (rs2653349) were genotyped. None of the SNPs showed significant main or G × E effects. However, a significant interaction effect between GHRL rs696217 and HCRTR1 rs2271933 was found to predict the PTSD Checklist (PCL-5) total score (P = 0.007). Further analysis revealed different interaction patterns in males and females. For females, the rs2271933 G allele was associated with an increased PCL-5 total score (B = 2.59, P = 0.024) when the rs696217 genotype TT/TG was present. For males, the rs696217 T allele is associated with an increased PCL-5 total score (B = 3.62, P = 0.040) when the rs2271933 genotype GG/GA was present. These current findings expand our knowledge of physiological function of the orexigenic hormone system, and suggest its involvement in development of fear-related mental disorders such as PTSD.
Collapse
Affiliation(s)
- Gen Li
- Laboratory for Traumatic Stress studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Kunlin Zhang
- Laboratory for Traumatic Stress studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
| | - Li Wang
- Laboratory for Traumatic Stress studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China.
| | - Chengqi Cao
- Laboratory for Traumatic Stress studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Shenzhen Key Laboratory of Affective and Social Cognitive Science, Shenzhen University, Shenzhen, China
| | - Ruojiao Fang
- Laboratory for Traumatic Stress studies and Center for Genetics and BioMedical Informatics Research, CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Ping Liu
- People's Hospital of Deyang City, Deyang, Sichuan, China
| | - Shu Luo
- People's Hospital of Deyang City, Deyang, Sichuan, China
| | - Israel Liberzon
- Department of Psychiatry, University of Michigan and Mental Health Service, VA Ann Arbor Healthcare System, Ann Arbor, MI, USA; Department of Psychology, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
37
|
Pourrahimi AM, Abbasnejad M, Esmaeili-Mahani S, Kooshki R, Raoof M. Intra-periaqueductal gray matter administration of orexin-A exaggerates pulpitis-induced anxiogenic responses and c-fos expression mainly through the interaction with orexin 1 and cannabinoid 1 receptors in rats. Neuropeptides 2019; 73:25-33. [PMID: 30587409 DOI: 10.1016/j.npep.2018.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 12/06/2018] [Accepted: 12/10/2018] [Indexed: 01/15/2023]
Abstract
Different types of trigeminal pains are frequently associated with psychophysiological concerns. Orexin-A and orexin 1 receptor (OX1R) are involved in modulation of both trigeminal pain and anxiety responses. Ventrolateral periaqueductal gray matter (vlPAG), a controlling site for nociception and emotion, receives orexinergic inputs. Here, the role of vlPAG OX1Rs and their interaction with cannabinoid 1 (CB1) receptor was evaluated in anxiety-like behavior following capsaicin-induced dental pulp pain. Rats were cannulated in the vlPAG and orexin-A was injected at the doses of 0.17, 0.35 and 0.51 μg/rat prior to the induction of pain. The elevated plus maze (EPM) and open field (OF) tests were used for assessing the anxiety responses. In addition, the induction of c-fos, in the vlPAG, was investigated using immunofluorescence microscopy. Capsaicin-treated rats displayed significantly higher anxiogenic behavior on EPM and OF tests. Pretreatment with orexin-A (0.51 μg/rat) attenuated capsaicin-mediated nociception, while exaggerated anxiogenic responses (p < 0.05). In addition, orexin-A effects were diminished by the administration of OX1R (SB-334867, 12 μg/rat) and cannabinoid 1 (AM251, 4 μg/rat) receptor antagonists. Intradental capsaicin induced a significant increase in c-fos expression in the vlPAG that was exaggerated by orexin-A (0.51 μg/rat). Blockage of OX1R and CB1 receptors attenuated the effect of orexin-A on c-fos expression in capsaicin-treated rats. In conclusion, the data suggest that manipulation of OX1R and CB1 receptors in the vlPAG alters capsaicin-evoked anxiety like behaviors and c-fos induction in rats.
Collapse
Affiliation(s)
- Ali Mohammad Pourrahimi
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Saeed Esmaeili-Mahani
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran; Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Razieh Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Maryam Raoof
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran; Department of Orofacial Pain and Dysfunction, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
| |
Collapse
|
38
|
Summers CH, Yaeger JDW, Staton CD, Arendt DH, Summers TR. Orexin/hypocretin receptor modulation of anxiolytic and antidepressive responses during social stress and decision-making: Potential for therapy. Brain Res 2018; 1731:146085. [PMID: 30590027 DOI: 10.1016/j.brainres.2018.12.036] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 12/15/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022]
Abstract
Hypothalmic orexin/hypocretin (Orx) neurons in the lateral and dorsomedial perifornical region (LH-DMH/PeF) innervate broadly throughout the brain, and receive similar inputs. This wide distribution, as well as two Orx peptides (OrxA and OrxB) and two Orx receptors (Orx1 and Orx2) allow for functionally related but distinctive behavioral outcomes, that include arousal, sleep-wake regulation, food seeking, metabolism, feeding, reward, addiction, and learning. These are all motivational functions, and tie the orexin systems to anxiety and depression as well. We present evidence, that for affective behavior, Orx1 and Orx2 receptors appear to have opposing functions. The majority of research on anxiety- and depression-related outcomes has focused on Orx1 receptors, which appear to have primarily anxiogenic and pro-depressive actions. Although there is significant research suggesting contrary findings, the primary potential for pharmacotherapies linked to the Orx1 receptor is via antagonists to block anxious and depressive behavior. Dual orexin receptor antagonists have been approved for treatment of sleep disorders, and are likely candidates for adaptation for affect disorder treatments. However, we present evidence here that demonstrates the Orx2 receptors are anxiolytic and antidepressive. Using a new experimental pre-clinical model of anxious and depressive behavior stimulated by social stress and decision-making that produces two stable behavioral phenotypes, Escape/Resilient and Stay/Susceptible, we tested the effects of intracerebroventricular injections of Orx2 agonist and antagonist drugs. Over ten behavioral measures, we have demonstrated that Orx2 agonists promote resilience, as well as anxiolytic and antidepressive behavior. In contrast, Orx2 antagonists or knockdown kindle anxious and pro-depressive behavior plus increase susceptibility. The results suggest that the Orx2 receptor may be a useful target for pharmacotherapies to treat anxiety and depression.
Collapse
Affiliation(s)
- Cliff H Summers
- Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA.
| | - Jazmine D W Yaeger
- Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA
| | - Clarissa D Staton
- Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA
| | - David H Arendt
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA
| | - Tangi R Summers
- Department of Biology, University of South Dakota, Vermillion, SD 57069 USA; Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD 57069 USA; Veterans Affairs Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD 57105 USA
| |
Collapse
|
39
|
Orexin as a modulator of fear-related behavior: Hypothalamic control of noradrenaline circuit. Brain Res 2018; 1731:146037. [PMID: 30481504 DOI: 10.1016/j.brainres.2018.11.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 11/19/2018] [Accepted: 11/23/2018] [Indexed: 12/20/2022]
Abstract
Fear is an important physiological function for survival. It appears when animals or humans are confronted with an environmental threat. The amygdala has been shown to play a highly important role in emergence of fear. Hypothalamic orexin neurons are activated by fearful stimuli to evoke a 'defense reaction' with an increase in arousal level and sympathetic outflow to deal with the imminent danger. However, how this system contributes to the emergence of fear-related behavior is not well understood. Orexin neurons in the hypothalamus send excitatory innervations to noradrenergic neurons in the locus coeruleus (NALC) which express orexin receptor 1 (OX1R) and send projections to the lateral amygdala (LA). Inhibition of this di-synaptic orexin → NALC → LA pathway by pharmacological or opto/chemogenetic methods reduces cue-induced fear expression. Excitatory manipulation of this pathway induces freezing, a fear-related behavior that only occurs when the environment contains some elements suggestive of danger. Although, fear memory helps animals respond to a context or cue previously paired with an aversive stimulus, fear-related behavior is sometimes evoked even in a distinct context containing some similar elements, which is known as fear generalization. Our recent observation suggests that the orexin → NALC → LA pathway might contribute to this response. This review focuses on recent advances regarding the role of hypothalamic orexin neurons in behavioral fear expression. We also discuss the potential effectiveness of orexin receptor antagonists for treating excessive fear response or overgeneralization seen in anxiety disorder and post-traumatic stress disorder (PTSD).
Collapse
|
40
|
Bahramzadeh Zoeram S, Elahdadi Salmani M, Lashkarbolouki T, Goudarzi I. Hippocampal orexin receptor blocking prevented the stress induced social learning and memory deficits. Neurobiol Learn Mem 2018; 157:12-23. [PMID: 30458283 DOI: 10.1016/j.nlm.2018.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 10/14/2018] [Accepted: 11/16/2018] [Indexed: 01/09/2023]
Abstract
Stress as a homeostatic challenge leads to the malfunction of learning and memory processes, namely social learning and memory. The orexin system is involved in stress responses through connections to the hypothalamic-pituitary axis (HPA). In addition, the hippocampus, a structure vulnerable to stress-induced changes, expresses orexin receptors 1 and 2 (OXr1 and OXr2) in various sub-regions. The present study is aimed at assessing the effects of hippocampal orexin receptor blockade on social learning and memory impairments and anxiety development following stress. Male Wistar rats (220-250 g) underwent cannula implantation in the hippocampus. Acute (two mild electric shocks, 5.5 mA) and chronic stresses (ten days of restraint, 6 h daily) were applied with or without injection of orexin receptor antagonists (SB-334867 or TCS OX 29). Sociability and social novelty in animals were assessed in a three-chamber social maze at the end of stress application. Anxiety and exploratory behavior of animals were then examined, with 20 min intervals, using the open field (OF) and elevated plus maze (EPM) tests, respectively. Cisterna Magna cerebro-spinal fluid (CSF) was drained, before sacrifice, for orexin (OX) assay and trunk blood was collected to measure the plasma corticosterone (CRT). Neither the acute nor the chronic stress could affect the sociability. The acute but not chronic stress prevented the animal from sniffing the familiar caged rat in the novelty session, a response which was reversed following the blockade of both OXRs. Furthermore, acute but not chronic stress, led to increased anxiety and immobility behavior which were both impeded by blocking the orexin receptor (OXR). Conversely, OX content in CSF increased due to chronic restraint stress, an effect that was reversed by orexin blockade. Finally, elevated plasma CRT was recorded in response to both acute and chronic stresses. The observed increase in plasma CRT in chronically-stressed rats was abolished following inhibition of OXRs, however a similar effect was not seen in the acute-stress group. Our results identify hippocampal OXRs as potential candidates capable of preventing acute stress-induced impairments of social novelty and anxiety behavior, and chronic stress-induced plasma CRT and CSF orexin, changes. OXR manipulation may improve adaptation to stress pathophysiology.
Collapse
Affiliation(s)
| | | | | | - Iran Goudarzi
- School of Biology, Damghan University, Damghan, Iran
| |
Collapse
|
41
|
Schmeichel BE, Matzeu A, Koebel P, Vendruscolo LF, Sidhu H, Shahryari R, Kieffer BL, Koob GF, Martin-Fardon R, Contet C. Knockdown of hypocretin attenuates extended access of cocaine self-administration in rats. Neuropsychopharmacology 2018; 43:2373-2382. [PMID: 29703996 PMCID: PMC6180106 DOI: 10.1038/s41386-018-0054-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 03/06/2018] [Accepted: 03/07/2018] [Indexed: 12/22/2022]
Abstract
The hypocretin/orexin (HCRT) neuropeptide system regulates feeding, arousal state, stress responses, and reward, especially under conditions of enhanced motivational relevance. In particular, HCRT neurotransmission facilitates drug-seeking behavior in circumstances that demand increased effort and/or motivation to take the drug. The present study used a shRNA-encoding adeno-associated viral vector to knockdown Hcrt expression throughout the dorsal hypothalamus in adult rats and determine the role of HCRT in cocaine self-administration. Chronic Hcrt silencing did not impact cocaine self-administration under short-access conditions, but robustly attenuated cocaine intake under extended access conditions, a model that mimics key features of compulsive cocaine taking. In addition, Hcrt silencing decreased motivation for both cocaine and a highly palatable food reward (i.e., sweetened condensed milk; SCM) under a progressive ratio schedule of reinforcement, but did not alter responding for SCM under a fixed ratio schedule. Importantly, Hcrt silencing did not affect food or water consumption, and had no consequence for general measures of arousal and stress reactivity. At the molecular level, chronic Hcrt knockdown reduced the number of neurons expressing dynorphin (DYN), and to a smaller extent melanin-concentrating hormone (MCH), in the dorsal hypothalamus. These original findings support the hypothesis that HCRT neurotransmission promotes operant responding for both drug and non-drug rewards, preferentially under conditions requiring a high degree of motivation. Furthermore, the current study provides compelling evidence for the involvement of the HCRT system in cocaine self-administration also under low-effort conditions in rats allowed extended access, possibly via functional interactions with DYN and MCH signaling.
Collapse
Affiliation(s)
- Brooke E Schmeichel
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA.
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA.
| | - Alessandra Matzeu
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Pascale Koebel
- Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 67404, France
| | - Leandro F Vendruscolo
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Harpreet Sidhu
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Roxana Shahryari
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Brigitte L Kieffer
- Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, 67404, France
- Douglas Institute Research Centre, McGill University, Montréal, QC, Canada
| | - George F Koob
- Neurobiology of Addiction Section, Intramural Research Program, National Institute on Drug Abuse, Baltimore, MD, 21224, USA
| | - Rémi Martin-Fardon
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Candice Contet
- Department of Neuroscience, The Scripps Research Institute, La Jolla, CA, 92037, USA
| |
Collapse
|
42
|
Abstract
The neuropeptides orexins are important in regulating the neurobiological systems that respond to stressful stimuli. Furthermore, orexins are known to play a role many of the phenotypes associated with stress-related mental illness such as changes in cognition, sleep-wake states, and appetite. Interestingly, orexins are altered in stress-related psychiatric disorders such as Major Depressive Disorder and Anxiety Disorders. Thus, orexins may be a potential target for treatment of these disorders. In this review, we will focus on what is known about the role of orexins in acute and repeated stress, in stress-induced phenotypes relevant to psychiatric illness in preclinical models, and in stress-related psychiatric illness in humans. We will also briefly discuss how orexins may contribute to sex differences in the stress response and subsequent phenotypes relevant to mental health, as many stress-related psychiatric disorders are twice as prevalent in women.
Collapse
|
43
|
Sargin D. The role of the orexin system in stress response. Neuropharmacology 2018; 154:68-78. [PMID: 30266600 DOI: 10.1016/j.neuropharm.2018.09.034] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 09/18/2018] [Accepted: 09/21/2018] [Indexed: 11/30/2022]
Abstract
Orexins are neuropeptides that are exclusively produced by hypothalamic neurons, which project throughout the entire brain. Orexin, also known as hypocretins, were initially identified to play a fundamental role in food intake, arousal and the regulation of sleep and wakefulness. Recent studies identified orexins to be critical for diverse physiological processes including motivation, reward, attention, emotional regulation, stress and anxiety. Here, I review recent findings that indicate orexin has an important role in acute and chronic stress. I also summarize the recent optogenetic and chemogenetic studies that have advanced our understanding of the orexin system. I will conclude by discussing clinical studies that implicate orexins in mental health disorders. This article is part of the Special Issue entitled 'Hypothalamic Control of Homeostasis'.
Collapse
Affiliation(s)
- Derya Sargin
- Hotchkiss Brain Institute and the Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, T2N 4N1, Canada.
| |
Collapse
|
44
|
Orexin 2 receptor stimulation enhances resilience, while orexin 2 inhibition promotes susceptibility, to social stress, anxiety and depression. Neuropharmacology 2018; 143:79-94. [PMID: 30240784 DOI: 10.1016/j.neuropharm.2018.09.016] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 08/28/2018] [Accepted: 09/11/2018] [Indexed: 02/08/2023]
Abstract
Knockdown of orexin/hypocretin 2 receptor (Orx2) in the basolateral amygdala (BLA) affects anxious and depressive behavior. We use a new behavioral paradigm, the Stress Alternatives Model (SAM), designed to improve translational impact. The SAM induces social stress in adult male mice by aggression from larger mice, allowing for adaptive decision-making regarding escape. In this model, mice remain (Stay) in the oval SAM arena or escape from social aggression (Escape) via routes only large enough for the smaller mouse. We hypothesized intracerebroventricular (icv) stimulation of Orx2 receptors would be anxiolytic and antidepressive in SAM-related social behavior and the Social Interaction/Preference (SIP) test. Conversely, we predicted that icv antagonism of Orx2 receptors would promote anxious and depressive behavior in these same tests. Anxious behaviors such as freezing (both cued and conflict) and startle are exhibited more often in Stay compared with Escape phenotype mice. Time spent attentive to the escape route is more frequent in Escape mice. In Stay mice, stimulation of Orx2 receptors reduces fear conditioning, conflict freezing and startle, and promotes greater attention to the escape hole. This anxiolysis was accompanied by activation of a cluster of inhibitory neurons in the amygdala. A small percentage of those Stay mice also begin escaping; whereas Escape is reversed by the Orx2 antagonist. Escape mice were also Resilient, and Stay mice Susceptible to stress (SIP), with both conditions reversed by Orx2 antagonism or stimulation respectively. Together, these results suggest that the Orx2 receptor may be a useful potential target for anxiolytic or antidepressive therapeutics.
Collapse
|
45
|
Burdakov D. How orexin signals bias action: Hypothalamic and accumbal circuits. Brain Res 2018; 1731:145943. [PMID: 30205111 DOI: 10.1016/j.brainres.2018.09.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 09/01/2018] [Accepted: 09/06/2018] [Indexed: 01/04/2023]
Abstract
Survival-maximizing, well-timed actions are a key responsibility of the brain. Hypothalamic neurons containing neurotransmitters orexins/hypocretins are important players in this process. Individuals without orexin neurons display inappropriately-timed transitions between arousal states, and other behavioural abnormalities including increased risk-taking. Deciphering neural circuits through which orexin neurons control brain states and behavior thus illuminates brain mechanisms of context-appropriate actions. This review outlines and puts into broader context recent examples of orexin circuit analyses in the lateral hypothalamus (LH) and the nucleus accumbens (NAc), two brain regions clasically implicated in context-appropriate actions. In the LH, orexin neurons excite GAD65-expressing neurons. The LH(GAD65) neuron excitation induces elevated locomotor activity, while inhibition of LH(GAD65) neuron natural activity depresses voluntary locomotion. The orexin → LH(GAD65) circuit may therefore assist in creating the drive to run. In the NAc shell region, orexin axons excite D2 neurons (dopamine-inhibited neurons expressing dopamine type-2 receptor). NAc(D2) cell activation increases risk-avoidance behaviors, while NAc(D2) cell inhibition reduces risk-avoidance. The excitatory orexin → NAc(D2) circuit may thus assist in reducing risk-taking, and oppose the inhibitory VTA(dopamine) → NAc(D2) circuit during computation of risk appetite. Neural computation in these local and long-range orexin circuits may thus assist in generating risk-avoiding locomotor responses to stressors known to activate orexin neurons, such as body energy depletion or potential external threats. A model is proposed where orexin-opposing, inhibitory inputs acting on the orexin target neurons may context-specifically channel orexin-induced brain excitation towards particular sets of actions.
Collapse
Affiliation(s)
- Denis Burdakov
- Swiss Federal Institute of Technology/ETH Zürich, Switzerland.
| |
Collapse
|
46
|
Abreu AR, Molosh AI, Johnson PL, Shekhar A. Role of medial hypothalamic orexin system in panic, phobia and hypertension. Brain Res 2018; 1731:145942. [PMID: 30205108 DOI: 10.1016/j.brainres.2018.09.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 12/11/2022]
Abstract
Orexin has been implicated in a number of physiological functions, including arousal, regulation of sleep, energy metabolism, appetitive behaviors, stress, anxiety, fear, panic, and cardiovascular control. In this review, we will highlight research focused on orexin system in the medial hypothalamic regions of perifornical (PeF) and dorsomedial hypothalamus (DMH), and describe the role of this hypothalamic neuropeptide in the behavioral expression of panic and consequent fear and avoidance responses, as well as sympathetic regulation and possible development of chronic hypertension. We will also outline recent data highlighting the clinical potential of single and dual orexin receptor antagonists for neuropsychiatric conditions including panic, phobia, and cardiovascular conditions, such as in hypertension.
Collapse
Affiliation(s)
- Aline R Abreu
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrei I Molosh
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Philip L Johnson
- Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Anantha Shekhar
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
| |
Collapse
|
47
|
Asadi S, Roohbakhsh A, Shamsizadeh A, Fereidoni M, Kordijaz E, Moghimi A. The effect of intracerebroventricular administration of orexin receptor type 2 antagonist on pentylenetetrazol-induced kindled seizures and anxiety in rats. BMC Neurosci 2018; 19:49. [PMID: 30103703 PMCID: PMC6090721 DOI: 10.1186/s12868-018-0445-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 07/17/2018] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Current antiepileptic drugs are not able to prevent recurrent seizures in all patients. Orexins are excitatory hypothalamic neuropeptides that their receptors (Orx1R and Orx2R) are found almost in all major regions of the brain. Pentylenetetrazol (PTZ)-induced kindling is a known experimental model for epileptic seizures. The purpose of this study was to evaluate the effect of Orx2 receptor antagonist (TCS OX2 29) on seizures and anxiety of PTZ-kindled rats. RESULTS Our results revealed that similar to valproate, administration of 7 µg/rat of TCS OX2 29 increased the latency period and decreased the duration time of 3rd and 4th stages of epileptiform seizures. Besides, it significantly decreased mean of seizure scores. However, TCS OX2 29 did not modulate anxiety induced by repeated PTZ administration. CONCLUSION This study showed that blockade of Orx2 receptor reduced seizure-related behaviors without any significant effect on PTZ-induced anxiety.
Collapse
Affiliation(s)
- Saeedeh Asadi
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Ali Roohbakhsh
- Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Shamsizadeh
- Physiology-Pharmacology Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran
| | - Masoud Fereidoni
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Elham Kordijaz
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran
| | - Ali Moghimi
- Department of Biology, Rayan Center for Neuroscience and Behavior, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran.
| |
Collapse
|
48
|
Tyree SM, Borniger JC, de Lecea L. Hypocretin as a Hub for Arousal and Motivation. Front Neurol 2018; 9:413. [PMID: 29928253 PMCID: PMC5997825 DOI: 10.3389/fneur.2018.00413] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/18/2018] [Indexed: 01/01/2023] Open
Abstract
The lateral hypothalamus is comprised of a heterogeneous mix of neurons that serve to integrate and regulate sleep, feeding, stress, energy balance, reward, and motivated behavior. Within these populations, the hypocretin/orexin neurons are among the most well studied. Here, we provide an overview on how these neurons act as a central hub integrating sensory and physiological information to tune arousal and motivated behavior accordingly. We give special attention to their role in sleep-wake states and conditions of hyper-arousal, as is the case with stress-induced anxiety. We further discuss their roles in feeding, drug-seeking, and sexual behavior, which are all dependent on the motivational state of the animal. We further emphasize the application of powerful techniques, such as optogenetics, chemogenetics, and fiber photometry, to delineate the role these neurons play in lateral hypothalamic functions.
Collapse
Affiliation(s)
- Susan M Tyree
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Jeremy C Borniger
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| | - Luis de Lecea
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, United States
| |
Collapse
|
49
|
Moorman DE. The hypocretin/orexin system as a target for excessive motivation in alcohol use disorders. Psychopharmacology (Berl) 2018; 235:1663-1680. [PMID: 29508004 PMCID: PMC5949267 DOI: 10.1007/s00213-018-4871-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 02/20/2018] [Indexed: 12/17/2022]
Abstract
The hypocretin/orexin (ORX) system has been repeatedly demonstrated to regulate motivation for drugs of abuse, including alcohol. In particular, ORX seems to be critically involved in highly motivated behaviors, as is observed in high-seeking individuals in a population, in the seeking of highly palatable substances, and in models of dependence. It seems logical that this system could be considered as a potential target for treatment for addiction, particularly alcohol addiction, as ORX pharmacological manipulations significantly reduce drinking. However, the ORX system also plays a role in a wide range of other behaviors, emotions, and physiological functions and is disrupted in a number of non-dependence-associated disorders. It is therefore important to consider how the ORX system might be optimally targeted for potential treatment for alcohol use disorders either in combination with or separate from its role in other functions or diseases. This review will focus on the role of ORX in alcohol-associated behaviors and whether and how this system could be targeted to treat alcohol use disorders while avoiding impacts on other ORX-relevant functions. A brief overview of the ORX system will be followed by a discussion of some of the factors that makes it particularly intriguing as a target for alcohol addiction treatment, a consideration of some potential challenges associated with targeting this system and, finally, some future directions to optimize new treatments.
Collapse
Affiliation(s)
- David E Moorman
- Department of Psychological and Brain Sciences, Neuroscience and Behavior Graduate Program, University of Massachusetts Amherst, 528 Tobin Hall, 135 Hicks Way, Amherst, MA, 01003, USA.
| |
Collapse
|
50
|
Grafe LA, Eacret D, Dobkin J, Bhatnagar S. Reduced Orexin System Function Contributes to Resilience to Repeated Social Stress. eNeuro 2018; 5:ENEURO.0273-17.2018. [PMID: 29662948 PMCID: PMC5900465 DOI: 10.1523/eneuro.0273-17.2018] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 01/31/2018] [Accepted: 02/05/2018] [Indexed: 12/12/2022] Open
Abstract
Exposure to stress increases the risk of developing affective disorders such as depression and post-traumatic stress disorder (PTSD). However, these disorders occur in only a subset of individuals, those that are more vulnerable to the effects of stress, whereas others remain resilient. The coping style adopted to deal with the stressor, either passive or active coping, is related to vulnerability or resilience, respectively. Important neural substrates that mediate responses to a stressor are the orexins. These neuropeptides are altered in the cerebrospinal fluid of patients with stress-related illnesses such as depression and PTSD. The present experiments used a rodent social defeat model that generates actively coping rats and passively coping rats, which we have previously shown exhibit resilient and vulnerable profiles, respectively, to examine if orexins play a role in these stress-induced phenotypes. In situ radiolabeling and qPCR revealed that actively coping rats expressed significantly lower prepro-orexin mRNA compared with passively coping rats. This led to the hypothesis that lower levels of orexins contribute to resilience to repeated social stress. To test this hypothesis, rats first underwent 5 d of social defeat to establish active and passive coping phenotypes. Then, orexin neurons were inhibited before each social defeat for three additional days using designer receptors exclusively activated by designer drugs (DREADDs). Inhibition of orexins increased social interaction behavior and decreased depressive-like behavior in the vulnerable population of rats. Indeed, these data suggest that lowering orexins promoted resilience to social defeat and may be an important target for treatment of stress-related disorders.
Collapse
Affiliation(s)
- Laura A. Grafe
- Department of Anesthesiology and Critical Care, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Darrell Eacret
- Department of Anesthesiology and Critical Care, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Jane Dobkin
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Seema Bhatnagar
- Department of Anesthesiology and Critical Care, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| |
Collapse
|