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Payet JM, Stevens L, Russo AM, Jaehne EJ, van den Buuse M, Kent S, Lowry CA, Baratta MV, Hale MW. The Role of Dorsal Raphe Nucleus Serotonergic Systems in Emotional Learning and Memory in Male BALB/c Mice. Neuroscience 2023; 534:1-15. [PMID: 37852412 DOI: 10.1016/j.neuroscience.2023.10.003] [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: 08/14/2023] [Revised: 10/04/2023] [Accepted: 10/06/2023] [Indexed: 10/20/2023]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the first-line pharmacological treatment for a variety of anxiety-, trauma- and stressor-related disorders. Although they are efficacious, therapeutic improvements require several weeks of treatment and are often associated with an initial exacerbation of symptoms. The dorsal raphe nucleus (DR) has been proposed as an important target for the modulation of emotional responses and the therapeutic effects of SSRIs. Using a fear-conditioning paradigm we aimed to understand how SSRIs affect emotional learning and memory, and their effects on serotonergic circuitry. Adult male BALB/c mice were treated with vehicle (n = 16) or the SSRI fluoxetine (18 mg/kg/d) acutely (n = 16), or chronically (21d, n = 16), prior to fear conditioning. Treatment was stopped, and half of the mice (n = 8/treatment group) were exposed to cued fear memory recall 72 h later. Activation of DR serotonergic neurons during fear conditioning (Experiment 1) or fear memory recall (Experiment 2), was measured using dual-label immunohistochemistry for Tph2 and c-Fos. Acute and chronic fluoxetine treatment reduced associative fear learning without affecting memory recall and had opposite effects on anxiety-like behaviour. Acute fluoxetine decreased serotonergic activity in the DR, while chronic treatment led to serotonergic activity that was indistinguishable from that of control levels in DRD and DRV subpopulations. Chronic fluoxetine facilitated fear extinction, which was associated with rostral DRD inhibition. These findings provide further evidence that SSRIs can alter aspects of learning and memory processes and are consistent with a role for discrete populations of DR serotonergic neurons in regulating fear- and anxiety-related behaviours.
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Affiliation(s)
- Jennyfer M Payet
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Laura Stevens
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Adrian M Russo
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Emily J Jaehne
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia; Department of Psychiatry, School of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Maarten van den Buuse
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Stephen Kent
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia
| | - Christopher A Lowry
- Department of Integrative Physiology and Centre for Neuroscience, University of Colorado Boulder, Boulder, Colorado, USA
| | - Michael V Baratta
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, Colorado, USA
| | - Matthew W Hale
- Department of Psychology, Counselling and Therapy, School of Psychology and Public Health, La Trobe University, Melbourne, Victoria, Australia.
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Vila-Merkle H, González-Martínez A, Campos-Jiménez R, Martínez-Ricós J, Teruel-Martí V, Lloret A, Blasco-Serra A, Cervera-Ferri A. Sex differences in amygdalohippocampal oscillations and neuronal activation in a rodent anxiety model and in response to infralimbic deep brain stimulation. Front Behav Neurosci 2023; 17:1122163. [PMID: 36910127 PMCID: PMC9995972 DOI: 10.3389/fnbeh.2023.1122163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 02/09/2023] [Indexed: 02/25/2023] Open
Abstract
Introduction Depression and anxiety are highly comorbid mental disorders with marked sex differences. Both disorders show altered activity in the amygdala, hippocampus, and prefrontal cortex. Infralimbic deep brain stimulation (DBS-IL) has anxiolytic and antidepressant effects, but the underlying mechanisms remain unclear. We aimed to contribute to understanding sex differences in the neurobiology of these disorders. Methods In male and female rats, we recorded neural oscillations along the dorsoventral axis of the hippocampus and the amygdala in response to an anxiogenic drug, FG-7142. Following this, we applied DBS-IL. Results Surprisingly, in females, the anxiogenic drug failed to induce most of the changes observed in males. We found sex differences in slow, delta, theta, and beta oscillations, and the amygdalo-hippocampal communication in response to FG-7142, with modest changes in females. Females had a more prominent basal gamma, and the drug altered this band only in males. We also analyzed c-Fos expression in both sexes in stress-related structures in response to FG-7142, DBS-IL, and combined interventions. With the anxiogenic drug, females showed reduced expression in the nucleus incertus, amygdala, septohippocampal network, and neocortical levels. In both experiments, the DBS-IL reversed FG-7142-induced effects, with a more substantial effect in males than females. Discussion Here, we show a reduced response in female rats which contrasts with the higher prevalence of anxiety in women but is consistent with other studies in rodents. Our results open compelling questions about sex differences in the neurobiology of anxiety and depression and their study in animal models.
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Affiliation(s)
- Hanna Vila-Merkle
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Alicia González-Martínez
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Rut Campos-Jiménez
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Joana Martínez-Ricós
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Vicent Teruel-Martí
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
| | - Ana Lloret
- Department of Physiology, Faculty of Medicine, Health Research Institute INCLIVA, CIBERFES, University of Valencia, Valencia, Spain
| | - Arantxa Blasco-Serra
- Study Group for the Anatomical Substrate of Pain and Analgesia (GESADA) Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine and Odontology, University of Valencia, Valencia, Spain
| | - Ana Cervera-Ferri
- Neuronal Circuits Laboratory, Department of Human Anatomy and Embryology, Faculty of Medicine, University of Valencia, Valencia, Spain
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Russo AM, Payet JM, Kent S, Lesku JA, Lowry CA, Hale MW. Acute treatment with 5-hydroxytryptophan increases social approach behaviour but does not activate serotonergic neurons in the dorsal raphe nucleus in juvenile male BALB/c mice: A model of human disorders with deficits of sociability. J Psychopharmacol 2022; 36:806-818. [PMID: 35475390 DOI: 10.1177/02698811221089039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND The BALB/c mouse has been proposed as a model of human psychiatric disorders characterised by elevated anxiety and altered sociability. Juvenile BALB/c mice show decreased social exploratory behaviour, increased anxiety, and reduced brain serotonin synthesis compared to other strains including C57BL/6J mice. AIM To determine whether supplementation of brain serotonin synthesis alters social behaviour and activation of serotonergic neurons across subregions of the dorsal raphe nucleus (DR) in BALB/c mice. METHODS Juvenile male BALB/c mice were assigned to one of four treatment conditions: vehicle/vehicle, carbidopa (25 mg/kg)/vehicle, vehicle/5-HTP (10 mg/kg), carbidopa (25 mg/kg)/5-HTP (10 mg/kg). Social behaviour was measured using the three-chamber social approach test, followed by immunohistochemical staining for TPH2 and c-Fos to measure activation of serotonergic neurons across subregions of the DR. RESULTS Mice treated with carbidopa/5-HTP spent more time in the social cage zone and covered more distance in the social approach test compared to other treatment groups. There was no difference between treatment groups in the activation of serotonergic neurons across subregions of the DR. However, the DRD was associated with increased social approach behaviour in carbidopa/5-HTP treated animals. CONCLUSIONS Supplementation of serotonin synthesis can increase social approach behaviour in juvenile BALB/c mice. An increase in locomotor behaviour was also observed suggesting that increasing central serotonin synthesis may have led to a reduction in state anxiety, manifesting in increased exploratory behaviour. As no effect on serotonergic activation within the DR was found, alternative mechanisms are likely important for the effects of 5-HTP on social behaviour.
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Affiliation(s)
- Adrian M Russo
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia
| | - Jennyfer M Payet
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia
| | - Stephen Kent
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne, VIC, Australia
| | - Christopher A Lowry
- Department of Integrative Physiology and Centre for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Matthew W Hale
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, Australia
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Gaskins DL, Burke AR, Sajdyk TJ, Truitt WA, Dietrich AD, Shekhar A. Role of Basolateral Amygdalar Somatostatin 2 Receptors in a Rat Model of Chronic Anxiety. Neuroscience 2021; 477:40-49. [PMID: 34487822 PMCID: PMC9744088 DOI: 10.1016/j.neuroscience.2021.08.031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/15/2022]
Abstract
Repeated exposure to stress has been implicated in inducing chronic anxiety states. Stress related increases in anxiety responses are likely mediated by activation of corticotropin-releasing factor receptors (CRFR) in the amygdala, particularly the basolateral amygdala (BLA). Within the BLA, acute injections of the CRFR agonist urocortin 1 (Ucn1) leads to acute anxiety, whereas repeated daily injections of subthreshold-doses of Ucn1 produces a long-lasting, persistent anxiety-like phenotype, a phenomenon referred to as Ucn1-priming. Relative gene expressions from the BLA of vehicle and Ucn1-primed rats were analyzed with quantitative RT-PCR using a predesigned panel of 82 neuroscience-related genes. Compared to vehicle-primed rats, only expression of the somatostatin receptor 2 gene (Sstr2) was significantly reduced in the BLA of Ucn1-primed rats. The contribution of Sstr2 on an anxiety phenotype was tested by injecting a Sstr2 antagonist into the BLA in un-primed rats. The Sstr2 antagonist increased anxiety-like behavior. Notably, pretreatment with Sstr2 agonist injected into the BLA blocked anxiety-inducing effects of acute Ucn1 BLA-injections and delayed anxiety expression during Ucn1-priming. However, concomitant Sstr2 agonist pretreatment during Ucn-1 priming did not prevent either the development of a chronic anxiety state or a reduction of BLA Sstr2 expression induced by priming. The data demonstrate that the persistent anxiety-like phenotype observed with Ucn1-priming in the BLA is associated with a selective reduction of Sstr2 gene expression. Although Sstr2 activation in the BLA blocks acute anxiogenic effects of stress and down-regulation of BLA Sstr2, it does not suppress the long-term consequences of prolonged exposure to stress-related challenges.
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Affiliation(s)
- Denise L Gaskins
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA; Graduate Program in Medical Neuroscience, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA
| | - Andrew R Burke
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA; Department of Anatomy Cellular Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Tammy J Sajdyk
- Department of Psychiatry, Indiana University School of Medicine, 355 W. 16th Street, Indianapolis, IN 46202, USA; Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, 410 W 10th St Suite 1000, Indianapolis, IN 46202, USA; Department of Pediatrics, Division of Hematology/Oncology, Indiana University School of Medicine, 705 Riley Hospital Drive, Indianapolis, IN 46202, USA
| | - William A Truitt
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA; Department of Anatomy Cellular Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
| | - Amy D Dietrich
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA; Department of Anatomy Cellular Biology & Physiology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Anantha Shekhar
- Stark Neurosciences Research Institute, Indiana University School of Medicine, 320 W. 15th Street, Indianapolis, IN 46202, USA; Department of Psychiatry, Indiana University School of Medicine, 355 W. 16th Street, Indianapolis, IN 46202, USA; Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, 410 W 10th St Suite 1000, Indianapolis, IN 46202, USA; Department of Psychiatry, University of Pittsburgh School of Medicine, 3550 Terrace Street, Suite 401, Pittsburgh, PA 15261, USA
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The Oscillatory Profile Induced by the Anxiogenic Drug FG-7142 in the Amygdala-Hippocampal Network Is Reversed by Infralimbic Deep Brain Stimulation: Relevance for Mood Disorders. Biomedicines 2021; 9:biomedicines9070783. [PMID: 34356846 PMCID: PMC8301458 DOI: 10.3390/biomedicines9070783] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/27/2021] [Accepted: 06/29/2021] [Indexed: 01/02/2023] Open
Abstract
Anxiety and depression exhibit high comorbidity and share the alteration of the amygdala–hippocampal–prefrontal network, playing different roles in the ventral and dorsal hippocampi. Deep brain stimulation of the infralimbic cortex in rodents or the human equivalent—the subgenual cingulate cortex—constitutes a fast antidepressant treatment. The aim of this work was: (1) to describe the oscillatory profile in a rodent model of anxiety, and (2) to deepen the therapeutic basis of infralimbic deep brain stimulation in mood disorders. First, the anxiogenic drug FG-7142 was administered to anaesthetized rats to characterize neural oscillations within the amygdala and the dorsoventral axis of the hippocampus. Next, deep brain stimulation was applied. FG-7142 administration drastically reduced the slow waves, increasing delta, low theta, and beta oscillations in the network. Moreover, FG-7142 altered communication in these bands in selective subnetworks. Deep brain stimulation of the infralimbic cortex reversed most of these FG-7142 effects. Cross-frequency coupling was also inversely modified by FG-7142 and by deep brain stimulation. Our study demonstrates that the hyperactivated amygdala–hippocampal network associated with the anxiogenic drug exhibits an oscillatory fingerprint. The study contributes to comprehending the neurobiological basis of anxiety and the effects of infralimbic deep brain stimulation.
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Payet JM, Wilson KE, Russo AM, Angiolino A, Kavanagh-Ryan W, Kent S, Lowry CA, Hale MW. Involvement of dorsal raphe nucleus serotonergic systems in social approach-avoidance behaviour and in the response to fluoxetine treatment in peri-adolescent female BALB/c mice. Behav Brain Res 2021; 408:113268. [PMID: 33811952 DOI: 10.1016/j.bbr.2021.113268] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/03/2021] [Accepted: 03/26/2021] [Indexed: 12/19/2022]
Abstract
Serotonergic systems are involved in the development and regulation of social behaviour, and drugs that target serotonin neurotransmission, such as selective serotonin reuptake inhibitors (SSRIs), also alter aspects of social approach-avoidance. The midbrain dorsal raphe nucleus (DR), which is a major serotonergic nucleus and main source of serotonergic innervation of the forebrain, has been proposed as an important target for SSRIs, although evidence in females is lacking. In this study, we examined the involvement of the DR serotonergic systems in social behaviour and in response to SSRI treatment, using peri-adolescent female BALB/c mice. Mice were exposed to the SSRI fluoxetine either chronically (18 mg/kg/day, in drinking water, for 12 days) or acutely (18 mg/kg, i.p.), or to vehicle control condition (0.9 % saline, i.p.), prior to being exposed to the three-chambered sociability test. Activation of serotonergic neurons across subregions of the DR were subsequently measured, using dual-label immunohistochemistry for TPH2 and c-Fos. Acute fluoxetine administration increased generalised and social avoidance, while mice exposed to chronic fluoxetine treatment showed levels of social approach behaviour that were comparable to controls. Serotonergic populations across the DR showed reduced activity following acute fluoxetine treatment. Further, activation of serotonergic neurons in the ventral DR correlated with social approach behaviour in vehicle-treated control mice. These data provide some support for the involvement of discrete populations of DR serotonergic neurons in the regulation of social approach-avoidance, although more research is needed to understand the effects and mechanisms of chronic SSRI treatment in females.
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Affiliation(s)
- Jennyfer M Payet
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Kira-Elise Wilson
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Adrian M Russo
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Anthony Angiolino
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - William Kavanagh-Ryan
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Stephen Kent
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Matthew W Hale
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC, 3086, Australia.
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Clinton SM, Shupe EA, Glover ME, Unroe KA, McCoy CR, Cohen JL, Kerman IA. Modeling heritability of temperamental differences, stress reactivity, and risk for anxiety and depression: Relevance to research domain criteria (RDoC). Eur J Neurosci 2021; 55:2076-2107. [PMID: 33629390 PMCID: PMC8382785 DOI: 10.1111/ejn.15158] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 01/29/2021] [Accepted: 02/20/2021] [Indexed: 01/04/2023]
Abstract
Animal models provide important tools to study biological and environmental factors that shape brain function and behavior. These models can be effectively leveraged by drawing on concepts from the National Institute of Mental Health Research Domain Criteria (RDoC) Initiative, which aims to delineate molecular pathways and neural circuits that underpin behavioral anomalies that transcend psychiatric conditions. To study factors that contribute to individual differences in emotionality and stress reactivity, our laboratory utilized Sprague-Dawley rats that were selectively bred for differences in novelty exploration. Selective breeding for low versus high locomotor response to novelty produced rat lines that differ in behavioral domains relevant to anxiety and depression, particularly the RDoC Negative Valence domains, including acute threat, potential threat, and loss. Bred Low Novelty Responder (LR) rats, relative to their High Responder (HR) counterparts, display high levels of behavioral inhibition, conditioned and unconditioned fear, avoidance, passive stress coping, anhedonia, and psychomotor retardation. The HR/LR traits are heritable, emerge in the first weeks of life, and appear to be driven by alterations in the developing amygdala and hippocampus. Epigenomic and transcriptomic profiling in the developing and adult HR/LR brain suggest that DNA methylation and microRNAs, as well as differences in monoaminergic transmission (dopamine and serotonin in particular), contribute to their distinct behavioral phenotypes. This work exemplifies ways that animal models such as the HR/LR rats can be effectively used to study neural and molecular factors driving emotional behavior, which may pave the way toward improved understanding the neurobiological mechanisms involved in emotional disorders.
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Affiliation(s)
- Sarah M Clinton
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Elizabeth A Shupe
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Matthew E Glover
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Keaton A Unroe
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Chelsea R McCoy
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
| | - Joshua L Cohen
- Department of Psychiatry and Behavioral Sciences, University of California, San Francisco, CA, USA
| | - Ilan A Kerman
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA.,Behavioral Health Service Line, Veterans Affairs Pittsburgh Health System, Pittsburgh, PA, USA
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Colangeli R, Teskey GC, Di Giovanni G. Endocannabinoid-serotonin systems interaction in health and disease. PROGRESS IN BRAIN RESEARCH 2021; 259:83-134. [PMID: 33541682 DOI: 10.1016/bs.pbr.2021.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Endocannabinoid (eCB) and serotonin (5-HT) neuromodulatory systems work both independently and together to finely orchestrate neuronal activity throughout the brain to strongly sculpt behavioral functions. Surprising parallelism between the behavioral effects of 5-HT and eCB activity has been widely reported, including the regulation of emotional states, stress homeostasis, cognitive functions, food intake and sleep. The distribution pattern of the 5-HT system and the eCB molecular elements in the brain display a strong overlap and several studies report a functional interplay and even a tight interdependence between eCB/5-HT signaling. In this review, we examine the available evidence of the interaction between the eCB and 5-HT systems. We first introduce the eCB system, then we describe the eCB/5-HT crosstalk at the neuronal and synaptic levels. Finally, we explore the potential eCB/5-HT interaction at the behavioral level with the implication for psychiatric and neurological disorders. The precise elucidation of how this neuromodulatory interaction dynamically regulates biological functions may lead to the development of more targeted therapeutic strategies for the treatment of depressive and anxiety disorders, psychosis and epilepsy.
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Affiliation(s)
- Roberto Colangeli
- Section of Neuroscience and Cell Biology, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy; Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada.
| | - G Campbell Teskey
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Giuseppe Di Giovanni
- Laboratory of Neurophysiology, Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta; Neuroscience Division, School of Biosciences, Cardiff University, Cardiff, United Kingdom
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Aravind A, Ravula AR, Chandra N, Pfister BJ. Behavioral Deficits in Animal Models of Blast Traumatic Brain Injury. Front Neurol 2020; 11:990. [PMID: 33013653 PMCID: PMC7500138 DOI: 10.3389/fneur.2020.00990] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 07/29/2020] [Indexed: 01/30/2023] Open
Abstract
Blast exposure has been identified to be the most common cause for traumatic brain injury (TBI) in soldiers. Over the years, rodent models to mimic blast exposures and the behavioral outcomes observed in veterans have been developed extensively. However, blast tube design and varying experimental parameters lead to inconsistencies in the behavioral outcomes reported across research laboratories. This review aims to curate the behavioral outcomes reported in rodent models of blast TBI using shockwave tubes or open field detonations between the years 2008–2019 and highlight the important experimental parameters that affect behavioral outcome. Further, we discuss the role of various design parameters of the blast tube that can affect the nature of blast exposure experienced by the rodents. Finally, we assess the most common behavioral tests done to measure cognitive, motor, anxiety, auditory, and fear conditioning deficits in blast TBI (bTBI) and discuss the advantages and disadvantages of these tests.
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Affiliation(s)
- Aswati Aravind
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Arun Reddy Ravula
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Namas Chandra
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Bryan J Pfister
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
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Bernabe CS, Caliman IF, Truitt WA, Molosh AI, Lowry CA, Hay-Schmidt A, Shekhar A, Johnson PL. Using loss- and gain-of-function approaches to target amygdala-projecting serotonergic neurons in the dorsal raphe nucleus that enhance anxiety-related and conditioned fear behaviors. J Psychopharmacol 2020; 34:400-411. [PMID: 32153226 PMCID: PMC9678127 DOI: 10.1177/0269881119900981] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The central serotonergic system originating from the dorsal raphe nucleus (DR) plays a critical role in anxiety and trauma-related disorders such as posttraumatic stress disorder. Although many studies have investigated the role of serotonin (5-HT) within pro-fear brain regions such as the amygdala, the majority of these studies have utilized non-selective pharmacological approaches or poorly understood lesioning techniques which limit their interpretation. AIM Here we investigated the role of amygdala-projecting 5-HT neurons in the DR in innate anxiety and conditioned fear behaviors. METHODS To achieve this goal, we utilized (1) selective lesion of 5-HT neurons projecting to the amygdala with saporin toxin conjugated to anti-serotonin transporter (SERT) injected into the amygdala, and (2) optogenetic excitation of amygdala-projecting DR cell bodies with a combination of a retrogradely transported canine adenovirus-expressing Cre-recombinase injected into the amygdala and a Cre-dependent-channelrhodopsin injected into the DR. RESULTS While saporin treatment lesioned both local amygdalar 5-HT fibers and neurons in the DR as well as reduced conditioned fear behavior, optical activation of amygdala-projecting DR neurons enhanced anxious behavior and conditioned fear response. CONCLUSION Collectively, these studies support the hypothesis that amygdala-projecting 5-HT neurons in the DR represent an anxiety and fear-on network.
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Affiliation(s)
- Cristian S. Bernabe
- Department of Anatomy & Cell Biology, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Stark Neurosciences Research Institute, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Izabela F. Caliman
- Department of Anatomy & Cell Biology, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William A. Truitt
- Department of Anatomy & Cell Biology, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Stark Neurosciences Research Institute, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Andrei I. Molosh
- Stark Neurosciences Research Institute, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Christopher A. Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | | | - Anantha Shekhar
- Stark Neurosciences Research Institute, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Philip L. Johnson
- Department of Anatomy & Cell Biology, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Stark Neurosciences Research Institute, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA,Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, USA
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Donner NC, Mani S, Fitz SD, Kienzle DM, Shekhar A, Lowry CA. Crh receptor priming in the bed nucleus of the stria terminalis (BNST) induces tph2 gene expression in the dorsomedial dorsal raphe nucleus and chronic anxiety. Prog Neuropsychopharmacol Biol Psychiatry 2020; 96:109730. [PMID: 31415826 PMCID: PMC6815726 DOI: 10.1016/j.pnpbp.2019.109730] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 07/31/2019] [Accepted: 08/03/2019] [Indexed: 11/28/2022]
Abstract
The bed nucleus of the stria terminalis (BNST) is a nodal structure in neural circuits controlling anxiety-related defensive behavioral responses. It contains neurons expressing the stress- and anxiety-related neuropeptide corticotropin-releasing hormone (Crh) as well as Crh receptors. Repeated daily subthreshold activation of Crh receptors in the BNST is known to induce a chronic anxiety-like state, but how this affects neurotransmitter-relevant gene expression in target regions of the BNST is still unclear. Since the BNST projects heavily to the dorsal raphe nucleus (DR), the main source of brain serotonin, we here tested the hypothesis that such repeated, anxiety-inducing activation of Crh receptors in the BNST alters the expression of serotonergic genes in the DR, including tph2, the gene encoding the rate-limiting enzyme for brain serotonin synthesis, and slc6a4, the gene encoding the serotonin transporter (SERT). For 5 days, adult male Wistar rats received daily, bilateral, intra-BNST microinjections of vehicle (1% bovine serum albumin in 0.9% saline, n = 11) or behaviorally subthreshold doses of urocortin 1 (Ucn1, n = 11), a potent Crh receptor agonist. Priming with Ucn1 increased tph2 mRNA expression selectively within the anxiety-related dorsal part of the DR (DRD) and decreased social interaction (SI) time, a measure of anxiety-related defensive behavioral responses in rodents. Decreased social interaction was strongly correlated with increased tph2 mRNA expression in the DRD. Together with previous studies, our data are consistent with the hypothesis that Crh-mediated control of the BNST/DRD-serotonergic system plays a key role in the development of chronic anxiety states, possibly also contributing to stress-induced relapses in drug abuse and addiction behavior.
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Affiliation(s)
- Nina C. Donner
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Sofia Mani
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Stephanie D. Fitz
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Drake M. Kienzle
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Anantha Shekhar
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
| | - Christopher A. Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA,Department of Physical Medicine & Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA,Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center (MIRECC), Rocky Mountain Regional Veterans Affairs Medical Center (RMRVAMC), Aurora, CO 80045, USA,Military and Veteran Microbiome: Consortium for Research and Education, Aurora, CO 80045, USA
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12
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Reinebrant HE, Wixey JA, Buller KM. Hypoxia-ischemia in the immature rodent brain impairs serotonergic neuronal function in certain dorsal raphé nuclei. Neural Regen Res 2020; 15:457-463. [PMID: 31571657 PMCID: PMC6921336 DOI: 10.4103/1673-5374.266067] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Neonatal hypoxia-ischemia (HI) results in losses of serotonergic neurons in specific dorsal raphé nuclei. However, not all serotonergic raphé neurons are lost and it is therefore important to assess the function of remaining neurons in order to understand their potential to contribute to neurological disorders in the HI-affected neonate. The main objective of this study was to determine how serotonergic neurons, remaining in the dorsal raphé nuclei after neonatal HI, respond to an external stimulus (restraint stress). On postnatal day 3 (P3), male rat pups were randomly allocated to one of the following groups: (i) control + no restraint (n = 5), (ii) control + restraint (n = 6), (iii) P3 HI + no restraint (n = 5) or (iv) P3 HI + restraint (n = 7). In the two HI groups, rat pups underwent surgery to ligate the common carotid artery and were then exposed to 6% O2 for 30 minutes. Six weeks after P3 HI, on P45, rats were subjected to restraint stress for 30 minutes. Using dual immunolabeling for Fos protein, a marker for neuronal activity, and serotonin (5-hydroxytrypamine; 5-HT), numbers of Fos-positive 5-HT neurons were determined in five dorsal raphé nuclei. We found that restraint stress alone increased numbers of Fos-positive 5-HT neurons in all five dorsal raphé nuclei compared to control animals. However, following P3 HI, the number of stress-induced Fos-positive 5-HT neurons was decreased significantly in the dorsal raphé ventrolateral, interfascicular and ventral nuclei compared with control animals exposed to restraint stress. In contrast, numbers of stress-induced Fos-positive 5-HT neurons in the dorsal raphé dorsal and caudal nuclei were not affected by P3 HI. These data indicate that not only are dorsal raphé serotonergic neurons lost after neonatal HI, but also remaining dorsal raphé serotonergic neurons have reduced differential functional viability in response to an external stimulus. Procedures were approved by the University of Queensland Animal Ethics Committee (UQCCR958/08/NHMRC) on February 27, 2009.
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Affiliation(s)
- Hanna E Reinebrant
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Julie A Wixey
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
| | - Kathryn M Buller
- UQ Centre for Clinical Research, Faculty of Medicine, The University of Queensland, Herston, Queensland, Australia
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13
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Arnold MR, Williams PH, McArthur JA, Archuleta AR, O'Neill CE, Hassell JE, Smith DG, Bachtell RK, Lowry CA. Effects of chronic caffeine exposure during adolescence and subsequent acute caffeine challenge during adulthood on rat brain serotonergic systems. Neuropharmacology 2019; 148:257-271. [PMID: 30579884 PMCID: PMC6438184 DOI: 10.1016/j.neuropharm.2018.12.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 12/13/2018] [Accepted: 12/15/2018] [Indexed: 01/09/2023]
Abstract
Caffeine is the most commonly used drug in the world. However, animal studies suggest that chronic consumption of caffeine during adolescence can result in enhanced anxiety-like behavioral responses during adulthood. One mechanism through which chronic caffeine administration may influence subsequent anxiety-like responses is through actions on brainstem serotonergic systems. In order to explore potential effects of chronic caffeine consumption on brainstem serotonergic systems, we evaluated the effects of a 28-day exposure to chronic caffeine (0.3 g/L; postnatal day 28-56) or vehicle administration in the drinking water, followed by 24 h caffeine withdrawal, and subsequent challenge with caffeine (30 mg/kg; s.c.) or vehicle in adolescent male rats. In Experiment 1, acute caffeine challenge induced a widespread activation of serotonergic neurons throughout the dorsal raphe nucleus (DR); this effect was attenuated in rats that had been exposed to chronic caffeine consumption. In Experiment 2, acute caffeine administration profoundly decreased tph2 and slc22a3 mRNA expression throughout the DR, with no effects on htr1a or slc6a4 mRNA expression. Chronic caffeine exposure for four weeks during adolescence was sufficient to decrease tph2 mRNA expression in the DR measured 28 h after caffeine withdrawal. Chronic caffeine administration during adolescence did not impact the ability of acute caffeine to decrease tph2 or slc22a3 mRNA expression. Together, these data suggest that both chronic caffeine administration during adolescence and acute caffeine challenge during adulthood are important determinants of serotonergic function and serotonergic gene expression, effects that may contribute to chronic effects of caffeine on anxiety-like responses.
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Affiliation(s)
- M R Arnold
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - P H Williams
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - J A McArthur
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - A R Archuleta
- Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA; Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - C E O'Neill
- Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA; Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - J E Hassell
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - D G Smith
- Department of Chemistry and Biochemistry, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - R K Bachtell
- Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA; Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA.
| | - C A Lowry
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO, 80309, USA; Department of Physical Medicine & Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA; Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center, Denver Veterans Affairs Medical Center (VAMC), Denver, CO, 80220, USA; Military and Veteran Microbiome Consortium for Research and Education (MVM-CoRE), Denver, CO, 80220, USA.
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Vilela-Costa HH, Spiacci A, Bissolli IG, Zangrossi H. A Shift in the Activation of Serotonergic and Non-serotonergic Neurons in the Dorsal Raphe Lateral Wings Subnucleus Underlies the Panicolytic-Like Effect of Fluoxetine in Rats. Mol Neurobiol 2019; 56:6487-6500. [DOI: 10.1007/s12035-019-1536-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/22/2019] [Indexed: 01/04/2023]
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15
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Klein AK, Purvis EM, Ayala K, Collins L, Krug JT, Mayes MS, Ettenberg A. Activation of 5-HT 1B receptors in the Lateral Habenula attenuates the anxiogenic effects of cocaine. Behav Brain Res 2019; 357-358:1-8. [PMID: 29660439 PMCID: PMC6186203 DOI: 10.1016/j.bbr.2018.04.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/22/2018] [Accepted: 04/11/2018] [Indexed: 01/01/2023]
Abstract
Recent work has implicated the Lateral Habenula (LHb) in the production of anxiogenic and aversive states. It is innervated by all the major monoamine neurotransmitter systems and has projections that have been shown to modulate the activity of both dopaminergic and serotonergic brain regions. Cocaine is a stimulant drug of abuse that potentiates neurotransmission in these monoamine systems and recent research suggests that the drug's behavioral effects may be related in part to its actions within the LHb. The present research was therefore devised to test the hypothesis that alterations in serotonin (5-HT) function within the LHb can affect the behavioral response to cocaine. Male rats were fitted with intracranial guide cannula and trained to traverse a straight alleyway once a day for a 1 mg/kg i.v. injection of cocaine. Intra-LHb pretreatment with the 5-HT1B agonist CP 94,253 (0, 0.1, or 0.25 μg/side) attenuated the development of approach/avoidance "retreat" behaviors known to be a consequence of cocaine's dual rewarding (approach) and anxiogenic (avoidance) properties. This effect was reversed by co-administration of a selective 5-HT1B antagonist, NAS-181 (0.1 μg/side), demonstrating drug specificity at the 5-HT1B receptor. These data suggest that 5-HT1B signaling within the LHb contributes to the anxiogenic effects of cocaine.
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Affiliation(s)
- Adam K Klein
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Erin M Purvis
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Kathy Ayala
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Lisette Collins
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Jacob T Krug
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Matthew S Mayes
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA
| | - Aaron Ettenberg
- Behavioral Pharmacology Laboratory, Department of Psychological and Brain Sciences, University of California, Santa Barbara, CA 93106-9660, USA.
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16
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Hassell JE, Nguyen KT, Gates CA, Lowry CA. The Impact of Stressor Exposure and Glucocorticoids on Anxiety and Fear. Curr Top Behav Neurosci 2019; 43:271-321. [PMID: 30357573 DOI: 10.1007/7854_2018_63] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Anxiety disorders and trauma- and stressor-related disorders, such as posttraumatic stress disorder (PTSD), are common and are associated with significant economic and social burdens. Although trauma and stressor exposure are recognized as a risk factors for development of anxiety disorders and trauma or stressor exposure is recognized as essential for diagnosis of PTSD, the mechanisms through which trauma and stressor exposure lead to these disorders are not well characterized. An improved understanding of the mechanisms through which trauma or stressor exposure leads to development and persistence of anxiety disorders or PTSD may result in novel therapeutic approaches for the treatment of these disorders. Here, we review the current state-of-the-art theories, with respect to mechanisms through which stressor exposure leads to acute or chronic exaggeration of avoidance or anxiety-like defensive behavioral responses and fear, endophenotypes in both anxiety disorders and trauma- and stressor-related psychiatric disorders. In this chapter, we will explore physiological responses and neural circuits involved in the development of acute and chronic exaggeration of anxiety-like defensive behavioral responses and fear states, focusing on the role of the hypothalamic-pituitary-adrenal (HPA) axis and glucocorticoid hormones.
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Affiliation(s)
- J E Hassell
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
- Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - K T Nguyen
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - C A Gates
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA
| | - C A Lowry
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO, USA.
- Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA.
- Department of Physical Medicine and Rehabilitation, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
- Veterans Health Administration, Rocky Mountain Mental Illness Research Education and Clinical Center, Denver Veterans Affairs Medical Center (VAMC), Denver, CO, USA.
- Military and Veteran Microbiome Consortium for Research and Education (MVM-CoRE), Denver, CO, USA.
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17
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Jalal B. The neuropharmacology of sleep paralysis hallucinations: serotonin 2A activation and a novel therapeutic drug. Psychopharmacology (Berl) 2018; 235:3083-3091. [PMID: 30288594 PMCID: PMC6208952 DOI: 10.1007/s00213-018-5042-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 09/17/2018] [Indexed: 12/21/2022]
Abstract
Sleep paralysis is a state of involuntary immobility occurring at sleep onset or offset, often accompanied by uncanny "ghost-like" hallucinations and extreme fear reactions. I provide here a neuropharmacological account for these hallucinatory experiences by evoking the role of the serotonin 2A receptor (5-HT2AR). Research has shown that 5-HT2AR activation can induce visual hallucinations, "mystical" subjective states, and out-of-body experiences (OBEs), and modulate fear circuits. Hallucinatory experiences triggered by serotonin-serotonergic ("pseudo") hallucinations, induced by hallucinogenic drugs-tend to be "dream-like" with the experiencer having insight ("meta-awareness") that he is hallucinating, unlike dopaminergic ("psychotic" and "life-like") hallucinations where such insight is lost. Indeed, hallucinatory experiences during sleep paralysis have the classic features of serotonergic hallucinations, and are strikingly similar to perceptual and subjective states induced by hallucinogenic drugs (e.g., lysergic acid diethylamide [LSD] and psilocybin), i.e., they entail visual hallucinations, mystical experiences, OBEs, and extreme fear reactions. I propose a possible mechanism whereby serotonin could be functionally implicated in generating sleep paralysis hallucinations and fear reactions through 5-HT2AR activity. Moreover, I speculate on the role of 5-HT2C receptors vis-à-vis anxiety and panic during sleep paralysis, and the orbitofrontal cortex-rich with 5-HT2A receptors-in influencing visual pathways during sleep paralysis, and, in effect, hallucinations. Finally, I propose, for the first time, a drug to target sleep paralysis hallucinations and fear reactions, namely the selective 5-HT2AR inverse agonist, pimavanserin. This account implicates gene HTR2A on chromosome 13q as the underlying cause of sleep paralysis hallucinations and could be explored using positron emission tomography.
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Affiliation(s)
- Baland Jalal
- Department of Psychiatry and Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, UK.
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18
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Auth CS, Weidner MT, Popp S, Strekalova T, Schmitt-Böhrer AG, van den Hove DLA, Lesch KP, Waider J. Differential anxiety-related behaviours and brain activation in Tph2-deficient female mice exposed to adverse early environment. Eur Neuropsychopharmacol 2018; 28:1270-1283. [PMID: 30146458 DOI: 10.1016/j.euroneuro.2018.07.103] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 07/26/2018] [Accepted: 07/30/2018] [Indexed: 12/11/2022]
Abstract
Anxiety disorders represent one of the most prevalent mental disorders in today's society and early adversity has been identified as major contributor to anxiety-related pathologies. Serotonin (5-hydroxytryptamine, 5-HT) is implicated in mediating the effects of early-life events on anxiety-like behaviours. In order to further elucidate the interaction of genetic predisposition and adversity in early, developmental stages on anxiety-related behaviours, the current study employed tryptophan hydroxylase 2 (Tph2)-deficient female mice, as a model for lifelong brain 5-HT synthesis deficiency. Offspring of this line were exposed to maternal separation (MS) and tested, in the open-field (OF) or the dark-light box (DLB). Subsequently, neural activity was assessed, using c-Fos immunohistochemistry. In the DLB, MS rescued the observed decrease in activity in the light compartment of homozygous Tph2-deficient mice and furthermore increased the incidence of escape-related jumps in animals of the same genotype. In the OF, MS increased escape-related behaviours in homo- and heterozygous Tph2-deficient offspring. On the neural level, both behavioural tests evoked a distinct activation pattern, as shown by c-Fos immunohistochemistry. Exposure to the DLB resulted in Tph2-dependent activation of paraventricular nucleus and basolateral amygdala, while OF exposure led to a specific activation in lateral amygdala of maternally separated animals and a Tph2 genotype- and MS-dependent activation of the ventrolateral and dorsolateral periaqueductal grey. Taken together, our findings suggest that MS promotes active responses to aversive stimuli, dependent on the availability of brain 5-HT. These effects might be mediated by the distinct activation of anxiety-relevant brain regions, due to the behavioural testing.
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Affiliation(s)
- Charlotte S Auth
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany
| | - Magdalena T Weidner
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands.
| | - Sandy Popp
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany
| | - Tatyana Strekalova
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands; Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Angelika G Schmitt-Böhrer
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany
| | - Daniel LA van den Hove
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands
| | - Klaus-Peter Lesch
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands; Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Jonas Waider
- Division of Molecular Psychiatry, Laboratory of Translational Neuroscience, Center of Mental Health, Department of Psychiatry, University of Würzburg, Würzburg, Germany
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Lawther AJ, Flavell A, Ma S, Kent S, Lowry CA, Gundlach AL, Hale MW. Involvement of Serotonergic and Relaxin-3 Neuropeptide Systems in the Expression of Anxiety-like Behavior. Neuroscience 2018; 390:88-103. [DOI: 10.1016/j.neuroscience.2018.08.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/12/2018] [Accepted: 08/07/2018] [Indexed: 12/12/2022]
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20
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Holschbach MA, Vitale EM, Lonstein JS. Serotonin-specific lesions of the dorsal raphe disrupt maternal aggression and caregiving in postpartum rats. Behav Brain Res 2018; 348:53-64. [PMID: 29653128 DOI: 10.1016/j.bbr.2018.04.008] [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: 02/27/2018] [Revised: 03/28/2018] [Accepted: 04/06/2018] [Indexed: 11/29/2022]
Abstract
The behavioral modifications associated with early motherhood, which include high aggression, caring for the young, and low anxiety, are all affected by acute pharmacological manipulation of serotonin signaling. However, the effects on all these behaviors of permanently disrupting serotonin signaling from one of its primary sources, the dorsal raphe nucleus (DR), have not been examined in detail. To address this, serotonin-specific lesions centered on the dorsomedial DR (DRdm; DR subregion strongly implicated in emotional behaviors) were induced at mid-pregnancy (day 15) or early postpartum (day 2) in rats using a saporin-conjugated neurotoxin targeting the serotonin transporter (Anti-SERT-SAP). Prepartum or postpartum Anti-SERT-SAP reduced DRdm serotonin immunoreactivity by ∼40-65%, and postpartum Anti-SERT-SAP also reduced it in the ventromedial and lateral wings of the DR, as well as in the median raphe. Serotonin-immunoreactive fibers were significantly reduced in the anterior hypothalamus, but not medial preoptic area, of lesioned dams. Pre- or postpartum lesions both greatly reduced maternal aggression, but while prepartum lesions did not affect later undisturbed maternal caregiving, the larger postpartum lesions prevented the postpartum decline in kyphotic nursing and reduced pup licking. Serotonin lesions did not affect pup retrieval, but the prepartum lesions temporarily increased maternal hovering over and licking the pups observed immediately after the disruptive retrieval tests. Dams' anxiety-like behaviors and litter weight gains were unaffected by the lesions. These findings suggest that DRdm serotonin projecting to the AH is particularly critical for maternal aggression, but that more widespread disruption of midbrain raphe serotonin is necessary to greatly impair maternal caregiving. Postpartum anxiety may rely more on other neurochemical systems or different midbrain serotonergic cell populations.
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Affiliation(s)
- M Allie Holschbach
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA
| | - Erika M Vitale
- Department of Psychology, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA
| | - Joseph S Lonstein
- Neuroscience Program, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA; Department of Psychology, 108 Giltner Hall, Michigan State University, East Lansing, MI, 48824, USA.
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21
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Two models of inescapable stress increase tph2 mRNA expression in the anxiety-related dorsomedial part of the dorsal raphe nucleus. Neurobiol Stress 2018. [PMID: 29520369 PMCID: PMC5842308 DOI: 10.1016/j.ynstr.2018.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Expression of TPH2, the rate-limiting enzyme for brain serotonin synthesis, is elevated in the dorsal raphe nucleus (DR) of depressed suicide victims. One hypothesis is that this increase in TPH2 expression is stress-induced. Here, we used an established animal model to address whether exposure to an acute stressor, inescapable tail shock (IS), increases tph2 mRNA and Tph2 protein expression, and if IS sensitizes the DR to a subsequent, heterotypic stressor. In Experiment 1, we measured tph2 mRNA expression 4 h after IS or home cage (HC) control conditions in male rats, using in situ hybridization histochemistry. In Experiment 2, we measured Tph2 protein expression 12 h or 24 h after IS using western blot. In Experiment 3, we measured tph2 mRNA expression following IS on Day 1, and cold swim stress (10 min, 15 °C) on Day 2. Inescapable tail shock was sufficient to increase tph2 mRNA expression 4 h and 28 h later, selectively in the dorsomedial DR (caudal aspect of the dorsal DR, cDRD; an area just rostral to the caudal DR, DRC) and increased Tph2 protein expression in the DRD (rostral and caudal aspects of the dorsal DR combined) 24 h later. Cold swim increased tph2 mRNA expression in the dorsomedial DR (cDRD) 4 h later. These effects were associated with increased immobility during cold swim, elevated plasma corticosterone, and a proinflammatory plasma cytokine milieu (increased interleukin (IL)-6, decreased IL-10). Our data demonstrate that two models of inescapable stress, IS and cold swim, increase tph2 mRNA expression selectively in the anxiety-related dorsomedial DR (cDRD).
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22
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Kreiss DS, De Deurwaerdère P. Purposeless oral activity induced by meta-chlorophenylpiperazine (m-CPP): Undefined tic-like behaviors? J Neurosci Methods 2017; 292:30-36. [PMID: 28483714 DOI: 10.1016/j.jneumeth.2017.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 03/20/2017] [Accepted: 05/05/2017] [Indexed: 01/04/2023]
Abstract
BACKGROUND The pathophysiological hypothesis underlying tic disorders in Tourette syndrome (TS) is that basal ganglia are not capable of properly filtering cortical information, leading patients with difficulties in inhibiting unwanted behaviors or impulses. One of the main challenges for furthering such a hypothesis is to find appropriate animal models summarizing some aspects of the disease. METHODS It has been established for more than 25 years in rodents that the prototypical serotonin (5-HT) agonist meta-chlorophenylpiperazine (m-CPP) elicits purposeless oral movements including chewing behavior. These bouts of oral movements, originally thought to mimic human oral dyskinesia consequent to long-term administration of antipsychotic drugs or parkinsonian tremor, could correspond to an undefined form of tics. Here, we describe the nature of the purposeless oral movements triggered by m-CPP and other agonists which could be associated with obsessive compulsive disorders. We report the pharmacology of this response with a focus on the 5-HT2C receptor subtype and the degree to which the dopaminergic and cholinergic systems are involved. The orofacial dyskinetic effects are related to the action of these compounds in associative/limbic territories of the basal ganglia, rather than sensorimotor ones, as expected from the human disease. CONCLUSION In spite of the low translational value of these oral movements, the neurobiological analysis of these oral movements could help to a better understanding of the pathophysiology of tics and compulsive disorders often cormorbid with TS.
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Affiliation(s)
- Deborah S Kreiss
- Washington and Lee University, Dept. of Psychology, Neuroscience Program, Lexington, VA, United States
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Burke AR, McCormick CM, Pellis SM, Lukkes JL. Impact of adolescent social experiences on behavior and neural circuits implicated in mental illnesses. Neurosci Biobehav Rev 2017; 76:280-300. [DOI: 10.1016/j.neubiorev.2017.01.018] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 11/11/2016] [Accepted: 01/06/2017] [Indexed: 12/18/2022]
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Wscieklica T, Silva MS, Lemes JA, Melo-Thomas L, Céspedes IC, Viana MB. Deep brain stimulation of the dorsal raphe inhibits avoidance and escape reactions and activates forebrain regions related to the modulation of anxiety/panic. Behav Brain Res 2017; 321:193-200. [DOI: 10.1016/j.bbr.2016.11.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Revised: 11/11/2016] [Accepted: 11/17/2016] [Indexed: 12/24/2022]
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Cohen JL, Ata AE, Jackson NL, Rahn EJ, Ramaker RC, Cooper S, Kerman IA, Clinton SM. Differential stress induced c-Fos expression and identification of region-specific miRNA-mRNA networks in the dorsal raphe and amygdala of high-responder/low-responder rats. Behav Brain Res 2017; 319:110-123. [PMID: 27865919 PMCID: PMC5183530 DOI: 10.1016/j.bbr.2016.11.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/19/2016] [Accepted: 11/08/2016] [Indexed: 01/03/2023]
Abstract
Chronic stress triggers a variety of physical and mental health problems, and how individuals cope with stress influences risk for emotional disorders. To investigate molecular mechanisms underlying distinct stress coping styles, we utilized rats that were selectively-bred for differences in emotionality and stress reactivity. We show that high novelty responding (HR) rats readily bury a shock probe in the defensive burying test, a measure of proactive stress coping behavior, while low novelty responding (LR) rats exhibit enhanced immobility, a measure of reactive coping. Shock exposure in the defensive burying test elicited greater activation of HR rats' caudal dorsal raphe serotonergic cells compared to LRs, but lead to more pronounced activation throughout LRs' amygdala (lateral, basolateral, central, and basomedial nuclei) compared to HRs. RNA-sequencing revealed 271 mRNA transcripts and 33 microRNA species that were differentially expressed in HR/LR raphe and amygdala. We mapped potential microRNA-mRNA networks by correlating and clustering mRNA and microRNA expression and identified networks that differed in either the HR/LR dorsal raphe or amygdala. A dorsal raphe network linked three microRNAs which were down-regulated in LRs (miR-206-3p, miR-3559-5p, and miR-378a-3p) to repression of genes related to microglia and immune response (Cd74, Cyth4, Nckap1l, and Rac2), the genes themselves were up-regulated in LR dorsal raphe. In the amygdala, another network linked miR-124-5p, miR-146a-5p, miR-3068-3p, miR-380-5p, miR-539-3p, and miR-7a-1-3p with repression of chromatin remodeling-related genes (Cenpk, Cenpq, Itgb3bp, and Mis18a). Overall this work highlights potential drivers of gene-networks and downstream molecular pathways within the raphe and amygdala that contribute to individual differences in stress coping styles and stress vulnerabilities.
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Affiliation(s)
- Joshua L Cohen
- Medical Scientist Training Program, University of Alabama-Birmingham, USA
| | - Anooshah E Ata
- University of Alabama-Birmingham School of Medicine, USA
| | - Nateka L Jackson
- Department of Neurobiology, University of Alabama-Birmingham, USA
| | - Elizabeth J Rahn
- Department of Neurobiology, University of Alabama-Birmingham, USA
| | - Ryne C Ramaker
- Medical Scientist Training Program, University of Alabama-Birmingham, USA; HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Sara Cooper
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Ilan A Kerman
- School of Neuroscience, Virginia Tech University, USA; Department of Psychiatry & Behavioral Medicine, Carilion Clinic, Virginia Tech Carilion School of Medicine, USA
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Attenuation of the anxiogenic effects of cocaine by 5-HT 1B autoreceptor stimulation in the bed nucleus of the stria terminalis of rats. Psychopharmacology (Berl) 2017; 234:485-495. [PMID: 27888284 PMCID: PMC5226880 DOI: 10.1007/s00213-016-4479-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
Abstract
RATIONALE Cocaine produces significant aversive/anxiogenic actions whose underlying neurobiology remains unclear. A possible substrate contributing to these actions is the serotonergic (5-HT) pathway projecting from the dorsal raphé (DRN) to regions of the extended amygdala, including the bed nucleus of the stria terminalis (BNST) which have been implicated in the production of anxiogenic states. OBJECTIVES The present study examined the contribution of 5-HT signaling within the BNST to the anxiogenic effects of cocaine as measured in a runway model of drug self-administration. METHODS Male Sprague-Dawley rats were fitted with bilateral infusion cannula aimed at the BNST and then trained to traverse a straight alley once a day for a single 1 mg/kg i.v. cocaine infusion delivered upon goal-box entry on each of 16 consecutive days/trials. Intracranial infusions of CP 94,253 (0, 0.25, 0.5, or 1.0 μg/side) were administered to inhibit local 5-HT release via activation of 5-HT1B autoreceptors. To confirm receptor specificity, the effects of this treatment were then challenged by co-administration of the selective 5-HT1B antagonist NAS-181. RESULTS Intra-BNST infusions of the 5-HT1B autoreceptor agonist attenuated the anxiogenic effects of cocaine as reflected by a decrease in runway approach-avoidance conflict behavior. This effect was reversed by the 5-HT1B antagonist. Neither start latencies (a measure of the subject's motivation to seek cocaine) nor spontaneous locomotor activity (an index of motoric capacity) were altered by either treatment. CONCLUSIONS Inhibition of 5-HT1B signaling within the BNST selectively attenuated the anxiogenic effects of cocaine, while leaving unaffected the positive incentive properties of the drug.
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Nicastro TM, Greenwood BN. Central monoaminergic systems are a site of convergence of signals conveying the experience of exercise to brain circuits involved in cognition and emotional behavior. Curr Zool 2016; 62:293-306. [PMID: 29491917 PMCID: PMC5804240 DOI: 10.1093/cz/zow027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/11/2016] [Indexed: 01/04/2023] Open
Abstract
Physical activity can enhance cognitive function and increase resistance against deleterious effects of stress on mental health. Enhanced cognitive function and stress resistance produced by exercise are conserved among vertebrates, suggesting that ubiquitous mechanisms may underlie beneficial effects of exercise. In the current review, we summarize the beneficial effects of exercise on cognitive function and stress resistance and discuss central and peripheral signaling factors that may be critical for conferring the effects of physical activity to brain circuits involved in cognitive function and stress. Additionally, it is suggested that norepinephrine and serotonin, highly conserved monoamines that are sensitive to exercise and able to modulate behavior in multiple species, could represent a convergence between peripheral and central exercise signals that mediate the beneficial effects of exercise. Finally, we offer the novel hypothesis that thermoregulation during exercise could contribute to the emotional effects of exercise by activating a subset of temperature-sensitive serotonergic neurons in the dorsal raphe nucleus that convey anxiolytic and stress-protective signals to forebrain regions. Throughout the review, we discuss limitations to current approaches and offer strategies for future research in exercise neuroscience.
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Donner NC, Siebler PH, Johnson DT, Villarreal MD, Mani S, Matti AJ, Lowry CA. Serotonergic systems in the balance: CRHR1 and CRHR2 differentially control stress-induced serotonin synthesis. Psychoneuroendocrinology 2016; 63:178-90. [PMID: 26454419 PMCID: PMC4695240 DOI: 10.1016/j.psyneuen.2015.09.024] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Revised: 09/21/2015] [Accepted: 09/22/2015] [Indexed: 12/14/2022]
Abstract
Anxiety and affective disorders are often associated with hypercortisolism and dysfunctional serotonergic systems, including increased expression of TPH2, the gene encoding the rate-limiting enzyme of neuronal serotonin synthesis. We previously reported that chronic glucocorticoid exposure is anxiogenic and increases rat Tph2 mRNA expression, but it was still unclear if this also translates to increased TPH2 protein levels and in vivo activity of the enzyme. Here, we found that adult male rats treated with corticosterone (CORT, 100 μg/ml) via the drinking water for 21 days indeed show increased TPH2 protein expression in the dorsal and ventral part of the dorsal raphe nucleus (DRD, DRV) during the light phase, abolishing the enzyme's diurnal rhythm. In a second study, we systemically blocked the conversion of 5-hydroxytryptophan (5-HTP) to serotonin immediately before rats treated with CORT or vehicle were either exposed to 30 min acoustic startle stress or home cage control conditions. This allowed us to measure 5-HTP accumulation as a direct readout of basal versus stress-induced in vivo TPH2 activity. As expected, basal TPH2 activity was elevated in the DRD, DRV and MnR of CORT-treated rats. In response to stress, a multitude of serotonergic systems reacted with increased TPH2 activity, but the stress-, anxiety-, and learned helplessness-related dorsal and caudal DR (DRD/DRC) displayed stress-induced increases in TPH2 activity only after chronic CORT-treatment. To address the mechanisms underlying this region-specific CORT-dependent sensitization, we stereotaxically implanted CORT-treated rats with cannulae targeting the DR, and pharmacologically blocked either corticotropin-releasing hormone receptor type 1 (CRHR1) or type 2 (CRHR2) 10 min prior to acoustic startle stress. CRHR2 blockade prevented stress-induced increases of TPH2 activity within the DRD/DRC, while blockade of CRHR1 potentiated stress-induced TPH2 activity in the entire DR. Stress-induced TPH2 activity in the DRD/DRC furthermore predicted TPH2 activity in the amygdala and in the caudal pontine reticular nucleus (PnC), while serotonin synthesis in the PnC was strongly correlated with the maximum startle response. Our data demonstrate that chronically elevated glucocorticoids sensitize stress- and anxiety-related serotonergic systems, and for the first time reveal competing roles of CRHR1 and CRHR2 on stress-induced in vivo serotonin synthesis.
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Affiliation(s)
- Nina C. Donner
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA,Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany,Corresponding author at: Nina C. Donner, Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Kraepelinstr. 2-10, 80804 Munich, Germany. Tel.: +49 (0)89 30622 554
| | - Philip H. Siebler
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
| | - Danté T. Johnson
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
| | - Marcos D. Villarreal
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
| | - Sofia Mani
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
| | - Allison J. Matti
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
| | - Christopher A. Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, 1725 Pleasant Street, 114 Clare Small, UCB 354, 80309 Boulder, CO, USA
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Lopes DA, Lemes JA, Melo-Thomas L, Schor H, de Andrade JS, Machado CM, Horta-Júnior JA, Céspedes IC, Viana MB. Unpredictable chronic mild stress exerts anxiogenic-like effects and activates neurons in the dorsal and caudal region and in the lateral wings of the dorsal raphe nucleus. Behav Brain Res 2016; 297:180-6. [DOI: 10.1016/j.bbr.2015.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Revised: 10/01/2015] [Accepted: 10/03/2015] [Indexed: 10/22/2022]
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Daniel SE, Rainnie DG. Stress Modulation of Opposing Circuits in the Bed Nucleus of the Stria Terminalis. Neuropsychopharmacology 2016; 41:103-25. [PMID: 26096838 PMCID: PMC4677121 DOI: 10.1038/npp.2015.178] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 05/22/2015] [Accepted: 06/17/2015] [Indexed: 12/11/2022]
Abstract
The anterior bed nucleus of the stria terminalis (BNST) has been recognized as a critical structure in regulating trait anxiety, contextual fear memory, and appetitive behavior, and is known to be sensitive to stress manipulations. As one of the most complex structures in the central nervous system, the intrinsic circuitry of the BNST is largely unknown; however, recent technological developments have allowed researchers to begin to untangle the internal connections of the nucleus. This research has revealed the possibility of two opposing circuits, one anxiolytic and one anxiogenic, within the BNST, the relative strength of which determines the behavioral outcome. The balance of these pathways is critical in maintaining a normal physiological and behavioral state; however, stress and drugs of abuse can differentially affect the opposing circuitry within the nucleus to shift the balance to a pathological state. In this review, we will examine how stress interacts with the neuromodulators, corticotropin-releasing factor, norepinephrine, dopamine, and serotonin to affect the circuitry of the BNST as well as how synaptic plasticity in the BNST is modulated by stress, resulting in long-lasting changes in the circuit and behavioral state.
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Affiliation(s)
- Sarah E Daniel
- Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
| | - Donald G Rainnie
- Psychiatry and Behavioral Sciences, Emory University School of Medicine, Atlanta, GA, USA
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Kangarlu-Haghighi K, Oryan S, Nasehi M, Zarrindast MR. The effect of BLA GABA(A) receptors in anxiolytic-like effect and aversive memory deficit induced by ACPA. EXCLI JOURNAL 2015; 14:613-26. [PMID: 26648818 PMCID: PMC4669909 DOI: 10.17179/excli2015-201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 03/09/2015] [Indexed: 11/10/2022]
Abstract
The roles of GABAergic receptors of the Basolateral amygdala (BLA) in the cannabinoid CB1 receptor agonist (arachydonilcyclopropylamide; ACPA)-induced anxiolytic-like effect and aversive memory deficit in adult male mice were examined in elevated plus-maze task. Results showed that pre-test intra-peritoneal injection of ACPA induced anxiolytic-like effect (at dose of 0.05 mg/kg) and aversive memory deficit (at doses of 0.025 and 0.05 mg/kg). The results revealed that Pre-test intra-BLA infusion of muscimol (GABAA receptor agonist; at doses of 0.1 and 0.2 µg/mouse) or bicuculline (GABAA receptor antagonist; at all doses) impaired and did not alter aversive memory, respectively. All previous GABA agents did not have any effects on anxiety-like behaviors. Interestingly, pretreatment with a sub-threshold dose of muscimol (0.025 µg/mouse) and bicuculline (0.025 µg/mouse) did not alter anxiolytic-like behaviors induced by ACPA, while both drugs restored ACPA-induced amnesia. Moreover, muscimol or bicuculline increased and decreased ACPA-induced locomotor activity, respectively. Finally the data may indicate that BLA GABAA receptors have critical and different roles in anxiolytic-like effect, aversive memory deficit and locomotor activity induced by ACPA.
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Affiliation(s)
| | - Shahrbanoo Oryan
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Nasehi
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran
| | - Mohammad-Reza Zarrindast
- Cognitive and Neuroscience Research Center (CNRC), Medical Genomics Research Center and School of Advanced Sciences in Medicine, Islamic Azad University, Tehran Medical Sciences Branch, Tehran, Iran ; Department of Pharmacology School of Medicine, Tehran University of Medical Sciences, Tehran, Iran ; Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran ; School of Cognitive Sciences, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran
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Zhang C, Chua BE, Yang A, Shabanpoor F, Hossain MA, Wade JD, Rosengren KJ, Smith CM, Gundlach AL. Central relaxin-3 receptor (RXFP3) activation reduces elevated, but not basal, anxiety-like behaviour in C57BL/6J mice. Behav Brain Res 2015; 292:125-32. [DOI: 10.1016/j.bbr.2015.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 05/29/2015] [Accepted: 06/03/2015] [Indexed: 01/02/2023]
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Anxiogenic drug administration and elevated plus-maze exposure in rats activate populations of relaxin-3 neurons in the nucleus incertus and serotonergic neurons in the dorsal raphe nucleus. Neuroscience 2015; 303:270-84. [DOI: 10.1016/j.neuroscience.2015.06.052] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/24/2015] [Accepted: 06/24/2015] [Indexed: 12/20/2022]
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Spiacci A, Pobbe RLH, Matthiesen M, Zangrossi H. 5-HT1A receptors of the rat dorsal raphe lateral wings and dorsomedial subnuclei differentially control anxiety- and panic-related defensive responses. Neuropharmacology 2015; 107:471-479. [PMID: 26145183 DOI: 10.1016/j.neuropharm.2015.06.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/24/2015] [Accepted: 06/27/2015] [Indexed: 01/04/2023]
Abstract
The dorsal raphe nucleus (DR), the main source of 5-HT projections to brain areas involved in anxiety regulation, is composed by 5 subnuclei that differ morphologically, functionally and neurochemically. Based on immunohistochemical evidence, it has been proposed that whereas 5-HT cells of the dorsomedial (dmDR) and caudal subnuclei are implicated in the pathophysiology of generalized anxiety disorder (GAD), neurons of the lateral wings (lwDR) are associated with panic disorder (PD). We here tested this hypothesis from a behavioral perspective by investigating the consequences of the non-selective stimulation of neurons within the dmDR and lwDR, or the pharmacological manipulation of 5-HT1A receptors located in these nuclei, of male Wistar rats exposed to the elevated T-maze. This test allows the measurement of both a GAD- (i.e. inhibitory avoidance) and a PD- (i.e. escape) related response in the same animal. Intra-dmDR injection of either the excitatory amino acid kainic acid or the 5-HT1A receptor antagonist WAY-100635 facilitated inhibitory avoidance acquisition, suggesting an anxiogenic effect, and inhibited escape expression, a panicolytic-like effect. Microinjection of the 5-HT1A receptor agonist 8-OH-DPAT caused the opposite effect. Administration of the same drugs into the lwDR only altered escape performance. Whereas kainic acid and 8-OH-DPAT facilitated its expression, WAY-100635 inhibited it. At higher doses, kainic acid administration evoked vigorous escape reactions as measured in an open-field. These findings implicate 5-HT neurons of the dmDR in the regulation of both GAD- and PD-related defensive behaviors. They also support a primary role of the lwDR in the mediation of PD-associated responses.
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Affiliation(s)
- Ailton Spiacci
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, São Paulo, Brazil
| | - Roger Luis Henschel Pobbe
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, São Paulo, Brazil
| | - Melina Matthiesen
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, São Paulo, Brazil
| | - Helio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, São Paulo, Brazil.
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Vasudeva RK, Hobby AR, Kirby LG. Ethanol consumption in the Sprague-Dawley rat increases sensitivity of the dorsal raphe nucleus to 5,7-dihydroxytryptamine. Behav Brain Res 2015; 295:35-44. [PMID: 26073764 DOI: 10.1016/j.bbr.2015.06.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/17/2015] [Accepted: 06/08/2015] [Indexed: 10/23/2022]
Abstract
Alcoholism afflicts 1 in 13 US adults, and comorbidity with depression is common. Levels of serotonin (5-HT) metabolites in alcoholic or depressed humans and rat strains are lower compared to healthy counterparts. Rats bred for ethanol (EtOH) preference are common in EtOH studies, however out-bred strains better model the range of EtOH consumption in humans. We examined voluntary EtOH consumption in out-bred Sprague-Dawley (SD) rats placed in the 20% EtOH intermittent access drinking paradigm (IA). Acquisition of 20% EtOH consumption (g EtOH/kg/24h) was assessed during the first 6-8 weeks of IA. Rats naturally separated into two groups (Drinkers or Non-drinkers) based on EtOH intake above or below 0.5 g/kg/24h prior to treatment intervention. We examined the effect of central 5-HT depletion on EtOH consumption by infusing 5,7-dihyroxytryptamine (5,7-DHT; i.c.v., 200-300 μg) or vehicle and measured EtOH consumption for 4 weeks post-operatively in IA. Compared to baseline, there was no effect of vehicle or 5,7-DHT on EtOH consumption during the post-operative period. Quantification of 5-HT depletion in the dorsal raphe nucleus (DRN) using tryptophan hydroxylase-2 (TPH2) immunohistochemistry resulted in a 76% decrease in staining with 5,7-DHT treatment. Interestingly, preservation of the ventromedial (VM) sub-regions was evident in all animals treated with 5,7-DHT, regardless of drinking behavior. In addition, Drinkers treated with 5,7-DHT had significantly more TPH2 depletion in the DRN compared to Non-drinkers. Our findings indicate that out-bred SD rats exhibit a natural EtOH consumption behavior (Drinker or Non-drinker) that is stable across time and independent of 5-HT depletion in the CNS. In addition, rats that regularly consumed >0.5 g EtOH/kg had greater sensitivity to 5,7-DHT in the DRN, indicating an interaction between EtOH and sensitivity of DRN 5-HT cells to neurotoxic substances. This may contribute to the dysfunctionality of the 5-HT system in alcoholic humans and lead to a better understanding of current pharmacological treatments for this addiction.
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Affiliation(s)
- Rani K Vasudeva
- Temple University School of Medicine, Center for Substance Abuse Research, 3500 North Broad St., Philadelphia, PA 19140, USA.
| | - Alexander R Hobby
- Temple University School of Medicine, Center for Substance Abuse Research, 3500 North Broad St., Philadelphia, PA 19140, USA
| | - Lynn G Kirby
- Temple University School of Medicine, Center for Substance Abuse Research, 3500 North Broad St., Philadelphia, PA 19140, USA
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Patki G, Ali Q, Pokkunuri I, Asghar M, Salim S. Grape powder treatment prevents anxiety-like behavior in a rat model of aging. Nutr Res 2015; 35:504-11. [PMID: 26022140 DOI: 10.1016/j.nutres.2015.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/09/2015] [Accepted: 05/11/2015] [Indexed: 12/20/2022]
Abstract
Earlier, we have reported that grape powder (GP) treatment prevented pharmacologic and psychological stress-induced anxiety-like behavior and memory impairment in rats. Protective effects of GP were attributed to its antioxidant effects. In this study, we tested the hypothesis that age-associated behavioral and cognitive deficits such as anxiety and memory impairment will be ameliorated with GP treatment. Using a National Institute of Aging recommended rodent model of aging, we examined a potentially protective role of antioxidant-rich GP in age-associated anxiety-like behavior and memory impairment. Male Fischer 344 rats were randomly assigned into 4 groups: young rats (3 months old) provided with tap water or with 15 g/L GP dissolved in tap water for 3 weeks, aged rats (21 months old) provided with tap water or with GP-treated tap water for 3 weeks (AG-GP). Anxiety-like behavior was significantly greater in aged rats compared with young rats, GP-treated young rats, or aged control rats (P < .05). Also, GP treatment prevented age-induced anxiety-like behavior in AG-GP rats (P < .05). Neither short-term nor long-term age-associated memory deficits improved with GP treatment in AG-GP rats. Furthermore, aged rats showed increased level of physiological stress (corticosterone) and increased oxidative stress in the plasma (8-isoprostane) as well as in selected brain areas (protein carbonylation). Grape powder treatment prevented age-induced increase in corticosterone levels and plasma 8-isoprostane levels in aged rats (P < .05), whereas protein carbonylation was recovered in the amygdala region only (P < .05). Grape powder by regulating oxidative stress ameliorates age-induced anxiety-like behavior in rats, whereas age-associated memory deficits seem unaffected with GP treatment.
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Affiliation(s)
- Gaurav Patki
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - Quaisar Ali
- Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Indira Pokkunuri
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - Mohammad Asghar
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA.
| | - Samina Salim
- Department of Pharmacological and Pharmaceutical Sciences, University of Houston, Houston, TX, USA.
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Patki G, Salvi A, Liu H, Atrooz F, Alkadhi I, Kelly M, Salim S. Tempol treatment reduces anxiety-like behaviors induced by multiple anxiogenic drugs in rats. PLoS One 2015; 10:e0117498. [PMID: 25793256 PMCID: PMC4367986 DOI: 10.1371/journal.pone.0117498] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 12/25/2014] [Indexed: 01/05/2023] Open
Abstract
We have published that pharmacological induction of oxidative stress (OS) causes anxiety-like behavior in rats. Using animal models, we also have established that psychological stress induces OS and leads to anxiety-like behaviors. All evidence points towards the causal role of OS in anxiety-like behaviors. To fully ascertain the role of OS in anxiety-like behaviors, it is reasonable to test whether the pro-anxiety effects of anxiogenic drugs caffeine or N-methyl-beta-carboline-3-carboxamide (FG-7142) can be mitigated using agents that minimize OS. In this study, osmotic pumps were either filled with antioxidant tempol or saline. The pumps were attached to the catheter leading to the brain cannula and inserted into the subcutaneous pocket in the back pocket of the rat. Continuous i.c.v. infusion of saline or tempol in the lateral ventricle of the brain (4.3 mmol/day) was maintained for 1 week. Rats were intraperitoneally injected either with saline or an anxiogenic drug one at a time. Two hours later all groups were subjected to behavioral assessments. Anxiety-like behavior tests (open-field, light-dark and elevated plus maze) suggested that tempol prevented anxiogenic drug-induced anxiety-like behavior in rats. Furthermore, anxiogenic drug-induced increase in stress examined via plasma corticosterone and increased oxidative stress levels assessed via plasma 8-isoprostane were prevented with tempol treatment. Protein carbonylation assay also suggested preventive effect of tempol in the prefrontal cortex brain region of rats. Antioxidant protein expression and pro-inflammatory cytokine levels indicate compromised antioxidant defense as well as an imbalance of inflammatory response.
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Affiliation(s)
- Gaurav Patki
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Ankita Salvi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Hesong Liu
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Fatin Atrooz
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Isam Alkadhi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Matthew Kelly
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
| | - Samina Salim
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, United States of America
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Sego C, Gonçalves L, Lima L, Furigo IC, Donato J, Metzger M. Lateral habenula and the rostromedial tegmental nucleus innervate neurochemically distinct subdivisions of the dorsal raphe nucleus in the rat. J Comp Neurol 2014; 522:1454-84. [PMID: 24374795 DOI: 10.1002/cne.23533] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 12/23/2013] [Accepted: 12/23/2013] [Indexed: 02/06/2023]
Abstract
The lateral habenula (LHb) is an epithalamic structure differentiated in a medial (LHbM) and a lateral division (LHbL). Together with the rostromedial tegmental nucleus (RMTg), the LHb has been implicated in the processing of aversive stimuli and inhibitory control of monoamine nuclei. The inhibitory LHb influence on midbrain dopamine neurons has been shown to be mainly mediated by the RMTg, a mostly GABAergic nucleus that receives a dominant input from the LHbL. Interestingly, the RMTg also projects to the dorsal raphe nucleus (DR), which also receives direct LHb projections. To compare the organization and transmitter phenotype of LHb projections to the DR, direct and indirect via the RMTg, we first placed injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin into the LHb or the RMTg. We then confirmed our findings by retrograde tracing and investigated a possible GABAergic phenotype of DR-projecting RMTg neurons by combining retrograde tracing with in situ hybridization for GAD67. We found only moderate direct LHb projections to the DR, which mainly emerged from the LHbM and were predominantly directed to the serotonin-rich caudal DR. In contrast, RMTg projections to the DR were more robust, emerged from RMTg neurons enriched in GAD67 mRNA, and were focally directed to a distinctive DR subdivision immunohistochemically characterized as poor in serotonin and enriched in presumptive glutamatergic neurons. Thus, besides its well-acknowledged role as a GABAergic control center for the ventral tegmental area (VTA)-nigra complex, our findings indicate that the RMTg is also a major GABAergic relay between the LHb and the DR.
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Affiliation(s)
- Chemutai Sego
- Department of Physiology & Biophysics, Institute of Biomedical Sciences, University of São Paulo, 05508-900, São Paulo, Brazil; Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, 05508-900, São Paulo, Brazil
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Paul ED, Johnson PL, Shekhar A, Lowry CA. The Deakin/Graeff hypothesis: focus on serotonergic inhibition of panic. Neurosci Biobehav Rev 2014; 46 Pt 3:379-96. [PMID: 24661986 PMCID: PMC4170046 DOI: 10.1016/j.neubiorev.2014.03.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 02/15/2014] [Accepted: 03/01/2014] [Indexed: 12/20/2022]
Abstract
The Deakin/Graeff hypothesis proposes that different subpopulations of serotonergic neurons through topographically organized projections to forebrain and brainstem structures modulate the response to acute and chronic stressors, and that dysfunction of these neurons increases vulnerability to affective and anxiety disorders, including panic disorder. We outline evidence supporting the existence of a serotonergic system originally discussed by Deakin/Graeff that is implicated in the inhibition of panic-like behavioral and physiological responses. Evidence supporting this panic inhibition system comes from the following observations: (1) serotonergic neurons located in the 'ventrolateral dorsal raphe nucleus' (DRVL) as well as the ventrolateral periaqueductal gray (VLPAG) inhibit dorsal periaqueductal gray-elicited panic-like responses; (2) chronic, but not acute, antidepressant treatment potentiates serotonin's panicolytic effect; (3) contextual fear activates a central nucleus of the amygdala-DRVL/VLPAG circuit implicated in mediating freezing and inhibiting panic-like escape behaviors; (4) DRVL/VLPAG serotonergic neurons are central chemoreceptors and modulate the behavioral and cardiorespiratory response to panicogenic agents such as sodium lactate and CO2. Implications of the panic inhibition system are discussed.
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Affiliation(s)
- Evan D Paul
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Philip L Johnson
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Anantha Shekhar
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
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Brooks LR, Pals HL, Enix CL, Woolaver RA, Paul ED, Lowry CA, Tsai PS. Fibroblast growth factor 8 deficiency compromises the functional response of the serotonergic system to stress. PLoS One 2014; 9:e101420. [PMID: 24992493 PMCID: PMC4081718 DOI: 10.1371/journal.pone.0101420] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 06/05/2014] [Indexed: 11/18/2022] Open
Abstract
Functionally heterogeneous populations of serotonergic neurons, located within the dorsal raphe nucleus (DR), play a role in stress-related behaviors and neuropsychiatric illnesses such as anxiety and depression. Abnormal development of these neurons may permanently alter their structure and connections, making the organism more susceptible to anxiety-related disorders. A factor that critically regulates the development of serotonergic neurons is fibroblast growth factor 8 (Fgf8). In this study, we used acute restraint stress followed by behavioral testing to examine whether Fgf8 signaling during development is important for establishing functional stress- and anxiety-related DR neurocircuits in adulthood. Wild-type and heterozygous male mice globally hypomorphic for Fgf8 were exposed to acute restraint stress and then tested for anxiety-like behavior on the elevated plus-maze. Further, we measured c-Fos immunostaining as a marker of serotonergic neuronal activation and tissue 5-hydroxyindoleacetic acid concentrations as a marker of serotonin functional output. Results showed that Fgf8 hypomorphs exhibited 1) an exaggerated response of DR anxiety-promoting circuits and 2) a blunted response of a DR panic-inhibiting circuit to stress, effects that together were associated with increased baseline anxiety-like behavior. Overall, our results provide a neural substrate upon which Fgf8 deficiency could affect stress response and support the hypothesis that developmental disruptions of serotonergic neurons affect their postnatal functional integrity.
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Affiliation(s)
- Leah R Brooks
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Heide L Pals
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Courtney L Enix
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Rachel A Woolaver
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Evan D Paul
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Christopher A Lowry
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Pei-San Tsai
- Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, Colorado, United States of America
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Ennaceur A. Tests of unconditioned anxiety - pitfalls and disappointments. Physiol Behav 2014; 135:55-71. [PMID: 24910138 DOI: 10.1016/j.physbeh.2014.05.032] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 04/21/2014] [Accepted: 05/28/2014] [Indexed: 02/05/2023]
Abstract
The plus-maze, the light-dark box and the open-field are the main current tests of unconditioned anxiety for mice and rats. Despite their disappointing achievements, they remain as popular as ever and seem to play an important role in an ever-growing demand for behavioral phenotyping and drug screening. Numerous reviews have repeatedly reported their lack of consistency and reliability but they failed to address the core question of whether these tests do provide unequivocal measures of fear-induced anxiety, that these measurements are not confused with measures of fear-induced avoidance or natural preference responses - i.e. discriminant validity. In the present report, I examined numerous issues that undermine the validity of the current tests, and I highlighted various flaws in the aspects of these tests and the methodologies pursued. This report concludes that the evidence in support of the validity of the plus-maze, the light/dark box and the open-field as anxiety tests is poor and methodologically questionable.
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Affiliation(s)
- A Ennaceur
- University of Sunderland, Department of Pharmacy, Wharncliffe Street, Sunderland SR1 3SD, UK.
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Howerton AR, Roland AV, Fluharty JM, Marshall A, Chen A, Daniels D, Beck SG, Bale TL. Sex differences in corticotropin-releasing factor receptor-1 action within the dorsal raphe nucleus in stress responsivity. Biol Psychiatry 2014; 75:873-83. [PMID: 24289884 PMCID: PMC3997756 DOI: 10.1016/j.biopsych.2013.10.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/26/2013] [Accepted: 10/16/2013] [Indexed: 11/19/2022]
Abstract
BACKGROUND Women are twice as likely as men to suffer from stress-related affective disorders. Corticotropin-releasing factor (CRF) is an important link between stress and mood, in part through its signaling in the serotonergic dorsal raphe (DR). Development of CRF receptor-1 (CRFr1) antagonists has been a focus of numerous clinical trials but has not yet been proven efficacious. We hypothesized that sex differences in CRFr1 modulation of DR circuits might be key determinants in predicting therapeutic responses and affective disorder vulnerability. METHODS Male and female mice received DR infusions of the CRFr1 antagonist, NBI 35965, or CRF and were evaluated for stress responsivity. Sex differences in indices of neural activation (cFos) and colocalization of CRFr1 throughout the DR were examined. Whole-cell patch-clamp electrophysiology assessed sex differences in serotonin neuron membrane characteristics and responsivity to CRF. RESULTS Males showed robust behavioral and hypothalamic-pituitary-adrenal axis responses to DR infusion of NBI 35965 and CRF, whereas females were minimally responsive. Sex differences were also found for both CRF-induced DR cFos and CRFr1 co-localization throughout the DR. Electrophysiologically, female serotonergic neurons showed blunted membrane excitability and divergent inhibitory postsynaptic current responses to CRF application. CONCLUSIONS These studies demonstrate convincing sex differences in CRFr1 activity in the DR, where blunted female responses to NBI 35965 and CRF suggest unique stress modulation of the DR. These sex differences might underlie affective disorder vulnerability and differential sensitivity to pharmacologic treatments developed to target the CRF system, thereby contributing to a current lack of CRFr1 antagonist efficacy in clinical trials.
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Affiliation(s)
- Alexis R Howerton
- Department of Animal Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alison V Roland
- Department of Animal Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jessica M Fluharty
- Department of Animal Biology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Anikò Marshall
- Department of Psychology, University at Buffalo, State University of New York, Buffalo, New York
| | - Alon Chen
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Derek Daniels
- Department of Psychology, University at Buffalo, State University of New York, Buffalo, New York
| | - Sheryl G Beck
- Department of Anesthesia, Children's Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania
| | - Tracy L Bale
- Department of Animal Biology, University of Pennsylvania, Philadelphia, Pennsylvania.
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Vasudeva RK, Waterhouse BD. Cellular profile of the dorsal raphe lateral wing sub-region: relationship to the lateral dorsal tegmental nucleus. J Chem Neuroanat 2014; 57-58:15-23. [PMID: 24704911 DOI: 10.1016/j.jchemneu.2014.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Revised: 02/25/2014] [Accepted: 03/04/2014] [Indexed: 01/09/2023]
Abstract
As one of the main serotonergic (5HT) projections to the forebrain, the dorsal raphe nucleus (DRN) has been implicated in disorders of anxiety and depression. Although the nucleus contains the densest population of 5HT neurons in the brain, at least 50% of cells within this structure are non-serotonergic, including a large population of nitric oxide synthase (NOS) containing neurons. The DRN has a unique topographical efferent organization and can also be divided into sub-regions based on rostro-caudal and medio-lateral dimensions. NOS is co-localized with 5HT in the midline DRN but NOS-positive cells in the lateral wing (LW) of the nucleus do not express 5HT. Interestingly, the NOS LW neuronal population is immediately rostral to and in line with the cholinergic lateral dorsal tegmental nucleus (LDT). We used immunohistochemical methods to investigate the potential serotonergic regulation of NOS LW neurons and also the association of this cell grouping to the LDT. Our results indicate that >75% of NOS LW neurons express the inhibitory 5HT1A receptor and are cholinergic (>90%). The findings suggest this assembly of cells is a rostral extension of the LDT, one that it is subject to regulation by 5HT release. As such the present study suggests a link between 5HT signaling, activation of cholinergic/NOS neurons, and the stress response including the pathophysiology underlying anxiety and depression.
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Affiliation(s)
- Rani K Vasudeva
- Temple University School of Medicine, Center for Substance Abuse Research, MERB 8th Floor, Philadelphia, PA 19140, United States; Drexel University College of Medicine, Department of Neurobiology & Anatomy, Queen Lane Campus, Philadelphia, PA 19129, United States.
| | - Barry D Waterhouse
- Drexel University College of Medicine, Department of Neurobiology & Anatomy, Queen Lane Campus, Philadelphia, PA 19129, United States.
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Chegini HR, Nasehi M, Zarrindast MR. Differential role of the basolateral amygdala 5-HT3 and 5-HT4 serotonin receptors upon ACPA-induced anxiolytic-like behaviors and emotional memory deficit in mice. Behav Brain Res 2014; 261:114-26. [DOI: 10.1016/j.bbr.2013.12.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 11/26/2013] [Accepted: 12/05/2013] [Indexed: 10/25/2022]
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Brooks LR, Enix CL, Rich SC, Magno JA, Lowry CA, Tsai PS. Fibroblast growth factor deficiencies impact anxiety-like behavior and the serotonergic system. Behav Brain Res 2014; 264:74-81. [PMID: 24512770 DOI: 10.1016/j.bbr.2014.01.053] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/07/2014] [Accepted: 01/30/2014] [Indexed: 02/07/2023]
Abstract
Serotonergic neurons in the dorsal raphe nucleus (DR) are organized in anatomically distinct subregions that form connections with specific brain structures to modulate diverse behaviors, including anxiety-like behavior. It is unclear if the functional heterogeneity of these neurons is coupled to their developmental heterogeneity, and if abnormal development of specific DR serotonergic subregions can permanently impact anxiety circuits and behavior. The goal of this study was to examine if deficiencies in different components of fibroblast growth factor (Fgf) signaling could preferentially impact the development of specific populations of DR serotonergic neurons to alter anxiety-like behavior in adulthood. Wild-type and heterozygous male mice globally hypomorphic for Fgf8, Fgfr1, or both (Fgfr1/Fgf8) were tested in an anxiety-related behavioral battery. Both Fgf8- and Fgfr1/Fgf8-deficient mice display increased anxiety-like behavior as measured in the elevated plus-maze and the open-field tests. Immunohistochemical staining of a serotonergic marker, tryptophan hydroxylase (Tph), revealed reductions in specific populations of serotonergic neurons in the ventral, interfascicular, and ventrolateral/ventrolateral periaqueductal gray subregions of the DR in all Fgf-deficient mice, suggesting a neuroanatomical basis for increased anxiety-like behavior. Overall, this study suggests Fgf signaling selectively modulates the development of different serotonergic neuron subpopulations. Further, it suggests anxiety-like behavior may stem from developmental disruption of these neurons, and individuals with inactivating mutations in Fgf signaling genes may be predisposed to anxiety disorders.
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Affiliation(s)
- Leah R Brooks
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA.
| | - Courtney L Enix
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Samuel C Rich
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Jinno A Magno
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
| | - Pei-San Tsai
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO, USA
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Issler O, Carter RN, Paul ED, Kelly PA, Olverman HJ, Neufeld-Cohen A, Kuperman Y, Lowry CA, Seckl JR, Chen A, Jamieson PM. Increased anxiety in corticotropin-releasing factor type 2 receptor-null mice requires recent acute stress exposure and is associated with dysregulated serotonergic activity in limbic brain areas. BIOLOGY OF MOOD & ANXIETY DISORDERS 2014; 4:1. [PMID: 24447313 PMCID: PMC4029322 DOI: 10.1186/2045-5380-4-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 12/11/2013] [Indexed: 11/28/2022]
Abstract
Background Corticotropin-releasing factor type 2 receptors (CRFR2) are suggested to facilitate successful recovery from stress to maintain mental health. They are abundant in the midbrain raphe nuclei, where they regulate serotonergic neuronal activity and have been demonstrated to mediate behavioural consequences of stress. Here, we describe behavioural and serotonergic responses consistent with maladaptive recovery from stressful challenge in CRFR2-null mice. Results CRFR2-null mice showed similar anxiety levels to control mice before and immediately after acute restraint stress, and also after cessation of chronic stress. However, they showed increased anxiety by 24 hours after restraint, whether or not they had been chronically stressed. Serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) contents were quantified and the level of 5-HIAA in the caudal dorsal raphe nucleus (DRN) was increased under basal conditions in CRFR2-null mice, indicating increased 5-HT turnover. Twenty-four hours following restraint, 5-HIAA was decreased only in CRFR2-null mice, suggesting that they had not fully recovered from the challenge. In efferent limbic structures, CRFR2-null mice showed lower levels of basal 5-HT in the lateral septum and subiculum, and again showed a differential response to restraint stress from controls. Local cerebral glucose utilization (LCMRglu) revealed decreased neuronal activity in the DRN of CRFR2-null mice under basal conditions. Following 5-HT receptor agonist challenge, LCMRglu responses indicated that 5-HT1A receptor responses in the DRN were attenuated in CRFR2-null mice. However, postsynaptic 5-HT receptor responses in forebrain regions were intact. Conclusions These results suggest that CRFR2 are required for proper functionality of 5-HT1A receptors in the raphe nuclei, and are key to successful recovery from stress. This disrupted serotonergic function in CRFR2-null mice likely contributes to their stress-sensitive phenotype. The 5-HT content in lateral septum and subiculum was notably altered. These areas are important for anxiety, and are also implicated in reward and the pathophysiology of addiction. The role of CRFR2 in stress-related psychopathologies deserves further consideration.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Pauline M Jamieson
- Centre for Cardiovascular Science, Queens Medical Research Institute, 47 Little France Crescent, Edinburgh EH16 4TJ, UK.
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Paul ED, Lowry CA. Functional topography of serotonergic systems supports the Deakin/Graeff hypothesis of anxiety and affective disorders. J Psychopharmacol 2013; 27:1090-106. [PMID: 23704363 DOI: 10.1177/0269881113490328] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Over 20 years ago, Deakin and Graeff hypothesized about the role of different serotonergic pathways in controlling the behavioral and physiologic responses to aversive stimuli, and how compromise of these pathways could lead to specific symptoms of anxiety and affective disorders. A growing body of evidence suggests these serotonergic pathways arise from topographically organized subpopulations of serotonergic neurons located in the dorsal and median raphe nuclei. We argue that serotonergic neurons in the dorsal/caudal parts of the dorsal raphe nucleus project to forebrain limbic regions involved in stress/conflict anxiety-related processes, which may be relevant for anxiety and affective disorders. Serotonergic neurons in the "lateral wings" of the dorsal raphe nucleus provide inhibitory control over structures controlling fight-or-flight responses. Dysfunction of this pathway could be relevant for panic disorder. Finally, serotonergic neurons in the median raphe nucleus, and the developmentally and functionally-related interfascicular part of the dorsal raphe nucleus, give rise to forebrain limbic projections that are involved in tolerance and coping with aversive stimuli, which could be important for affective disorders like depression. Elucidating the mechanisms through which stress activates these topographically and functionally distinct serotonergic pathways, and how dysfunction of these pathways leads to symptoms of neuropsychiatric disorders, may lead to the development of novel approaches to both the prevention and treatment of anxiety and affective disorders.
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Affiliation(s)
- Evan D Paul
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, USA
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Giles GE, Mahoney CR, Brunyé TT, Taylor HA, Kanarek RB. Caffeine promotes global spatial processing in habitual and non-habitual caffeine consumers. Front Hum Neurosci 2013; 7:694. [PMID: 24146646 PMCID: PMC3797965 DOI: 10.3389/fnhum.2013.00694] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 10/02/2013] [Indexed: 11/13/2022] Open
Abstract
Information processing is generally biased toward global cues, often at the expense of local information. Equivocal extant data suggests that arousal states may accentuate either a local or global processing bias, at least partially dependent on the nature of the manipulation, task, and stimuli. To further differentiate the conditions responsible for such equivocal results we varied caffeine doses to alter physiological arousal states and measured their effect on tasks requiring the retrieval of local versus global spatial knowledge. In a double-blind, repeated-measures design, non-habitual (Experiment 1; N = 36, M = 42.5 ± 28.7 mg/day caffeine) and habitual (Experiment 2; N = 34, M = 579.5 ± 311.5 mg/day caffeine) caffeine consumers completed four test sessions corresponding to each of four caffeine doses (0, 100, 200, 400 mg). During each test session, participants consumed a capsule containing one of the three doses of caffeine or placebo, waited 60 min, and then completed two spatial tasks, one involving memorizing maps and one spatial descriptions. A spatial statement verification task tested local versus global spatial knowledge by differentially probing memory for proximal versus distal landmark relationships. On the map learning task, results indicated that caffeine enhanced memory for distal (i.e., global) compared to proximal (i.e., local) comparisons at 100 (marginal), 200, and 400 mg caffeine in non-habitual consumers, and marginally beginning at 200 mg caffeine in habitual consumers. On the spatial descriptions task, caffeine enhanced memory for distal compared to proximal comparisons beginning at 100 mg in non-habitual but not habitual consumers. We thus provide evidence that caffeine-induced physiological arousal amplifies global spatial processing biases, and these effects are at least partially driven by habitual caffeine consumption.
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Affiliation(s)
- Grace E Giles
- Department of Psychology, Tufts University , Medford, MA , USA
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Fox JH, Lowry CA. Corticotropin-releasing factor-related peptides, serotonergic systems, and emotional behavior. Front Neurosci 2013; 7:169. [PMID: 24065880 PMCID: PMC3778254 DOI: 10.3389/fnins.2013.00169] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 08/30/2013] [Indexed: 12/01/2022] Open
Abstract
Corticotropin-releasing factor (CRF) is a 41-amino acid neuropeptide that is involved in stress-related physiology and behavior, including control of the hypothalamic-pituitary-adrenal (HPA) axis. Members of the CRF family of neuropeptides, including urocortin 1 (UCN 1), UCN 2, and UCN 3, bind to the G protein-coupled receptors, CRF type 1 (CRF1) and CRF2 receptors. In addition, CRF binding protein (CRFBP) binds both CRF and UCN 1 and can modulate their activities. There are multiple mechanisms through which CRF-related peptides may influence emotional behavior, one of which is through altering the activity of brainstem neuromodulatory systems, including serotonergic systems. CRF and CRF-related peptides act within the dorsal raphe nucleus (DR), the major source for serotonin (5-HT) in the brain, to alter the neuronal activity of specific subsets of serotonergic neurons and to influence stress-related behavior. CRF-containing axonal fibers innervate the DR in a topographically organized manner, which may contribute to the ability of CRF to alter the activity of specific subsets of serotonergic neurons. CRF and CRF-related peptides can either increase or decrease serotonergic neuronal firing rates and serotonin release, depending on their concentrations and on the specific CRF receptor subtype(s) involved. This review aims to describe the interactions between CRF-related peptides and serotonergic systems, the consequences for stress-related behavior, and implications for vulnerability to anxiety and affective disorders.
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Affiliation(s)
- James H Fox
- Behavioral Neuroendocrinology Laboratory, Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder Boulder, CO, USA
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Porciúncula LO, Sallaberry C, Mioranzza S, Botton PHS, Rosemberg DB. The Janus face of caffeine. Neurochem Int 2013; 63:594-609. [PMID: 24055856 DOI: 10.1016/j.neuint.2013.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 09/04/2013] [Accepted: 09/06/2013] [Indexed: 12/20/2022]
Abstract
Caffeine is certainly the psychostimulant substance most consumed worldwide. Over the past years, chronic consumption of caffeine has been associated with prevention of cognitive decline associated to aging and mnemonic deficits of brain disorders. While its preventive effects have been reported extensively, the cognitive enhancer properties of caffeine are relatively under debate. Surprisingly, there are scarce detailed ontogenetic studies focusing on neurochemical parameters related to the effects of caffeine during prenatal and earlier postnatal periods. Furthermore, despite the large number of epidemiological studies, it remains unclear how safe is caffeine consumption during pregnancy and brain development. Thus, the purpose of this article is to review what is currently known about the actions of caffeine intake on neurobehavioral and adenosinergic system during brain development. We also reviewed other neurochemical systems affected by caffeine, but not only during brain development. Besides, some recent epidemiological studies were also outlined with the control of "pregnancy signal" as confounding variable. The idea is to tease out how studies on the impact of caffeine consumption during brain development deserve more attention and further investigation.
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Affiliation(s)
- Lisiane O Porciúncula
- Laboratório de Estudos sobre o Sistema Purinérgico, Departamento de Bioquímica/ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, Porto Alegre/RS, Brazil.
| | - Cássia Sallaberry
- Laboratório de Estudos sobre o Sistema Purinérgico, Departamento de Bioquímica/ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, Porto Alegre/RS, Brazil
| | - Sabrina Mioranzza
- Laboratório de Estudos sobre o Sistema Purinérgico, Departamento de Bioquímica/ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, Porto Alegre/RS, Brazil
| | - Paulo Henrique S Botton
- Laboratório de Estudos sobre o Sistema Purinérgico, Departamento de Bioquímica/ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, Porto Alegre/RS, Brazil
| | - Denis B Rosemberg
- Laboratório de Estudos sobre o Sistema Purinérgico, Departamento de Bioquímica/ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600-anexo, Porto Alegre/RS, Brazil; Laboratório de Genética e Ecotoxicologia Molecular, Programa de Pós-graduação em Ciências Ambientais, Área de Ciências Exatas e Ambientais, Universidade Comunitária da Região de Chapecó. Avenida Senador Attílio Fontana, 591E, 89809-000 Chapecó/SC, Brazil
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