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Higa GSV, Viana FJC, Francis-Oliveira J, Cruvinel E, Franchin TS, Marcourakis T, Ulrich H, De Pasquale R. Serotonergic neuromodulation of synaptic plasticity. Neuropharmacology 2024; 257:110036. [PMID: 38876308 DOI: 10.1016/j.neuropharm.2024.110036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 06/16/2024]
Abstract
Synaptic plasticity constitutes a fundamental process in the reorganization of neural networks that underlie memory, cognition, emotional responses, and behavioral planning. At the core of this phenomenon lie Hebbian mechanisms, wherein frequent synaptic stimulation induces long-term potentiation (LTP), while less activation leads to long-term depression (LTD). The synaptic reorganization of neuronal networks is regulated by serotonin (5-HT), a neuromodulator capable of modify synaptic plasticity to appropriately respond to mental and behavioral states, such as alertness, attention, concentration, motivation, and mood. Lately, understanding the serotonergic Neuromodulation of synaptic plasticity has become imperative for unraveling its impact on cognitive, emotional, and behavioral functions. Through a comparative analysis across three main forebrain structures-the hippocampus, amygdala, and prefrontal cortex, this review discusses the actions of 5-HT on synaptic plasticity, offering insights into its role as a neuromodulator involved in emotional and cognitive functions. By distinguishing between plastic and metaplastic effects, we provide a comprehensive overview about the mechanisms of 5-HT neuromodulation of synaptic plasticity and associated functions across different brain regions.
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Affiliation(s)
- Guilherme Shigueto Vilar Higa
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil; Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Felipe José Costa Viana
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - José Francis-Oliveira
- Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, Birmingham, AL, 35233, USA
| | - Emily Cruvinel
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Thainá Soares Franchin
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Tania Marcourakis
- Departamento de Análises Clínicas e Toxicológicas, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil
| | - Henning Ulrich
- Departamento de Bioquímica, Instituto de Química (USP), Butantã, São Paulo, SP, 05508-900, Brazil
| | - Roberto De Pasquale
- Laboratório de Neurofisiologia, Departamento de Fisiologia e Biofísica, Universidade de São Paulo, Butantã, São Paulo, SP, 05508-000, Brazil.
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2
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Bernabe CS, Caliman IF, de Abreu ARR, Molosh AI, Truitt WA, Shekhar A, Johnson PL. Identification of a novel perifornical-hypothalamic-area-projecting serotonergic system that inhibits innate panic and conditioned fear responses. Transl Psychiatry 2024; 14:60. [PMID: 38272876 PMCID: PMC10811332 DOI: 10.1038/s41398-024-02769-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 01/06/2024] [Accepted: 01/10/2024] [Indexed: 01/27/2024] Open
Abstract
The serotonin (5-HT) system is heavily implicated in the regulation of anxiety and trauma-related disorders such as panic disorder and post-traumatic stress disorder, respectively. However, the neural mechanisms of how serotonergic neurotransmission regulates innate panic and fear brain networks are poorly understood. Our earlier studies have identified that orexin (OX)/glutamate neurons within the perifornical hypothalamic area (PFA) play a critical role in adaptive and pathological panic and fear. While site-specific and electrophysiological studies have shown that intracranial injection and bath application of 5-HT inhibits PFA neurons via 5-HT1a receptors, they largely ignore circuit-specific neurotransmission and its physiological properties that occur in vivo. Here, we investigate the role of raphe nuclei 5-HT inputs into the PFA in panic and fear behaviors. We initially confirmed that photostimulation of glutamatergic neurons in the PFA of rats produces robust cardioexcitation and flight/aversive behaviors resembling panic-like responses. Using the retrograde tracer cholera toxin B, we determined that the PFA receives discrete innervation of serotonergic neurons clustered in the lateral wings of the dorsal (lwDRN) and in the median (MRN) raphe nuclei. Selective lesions of these serotonergic projections with saporin toxin resulted in similar panic-like responses during the suffocation-related CO2 challenge and increased freezing to fear-conditioning paradigm. Conversely, selective stimulation of serotonergic fibers in the PFA attenuated both flight/escape behaviors and cardioexcitation responses elicited by the CO2 challenge and induced conditioned place preference. The data here support the hypothesis that PFA projecting 5-HT neurons in the lwDRN/MRN represents a panic/fear-off circuit and may also play a role in reward behavior.
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Affiliation(s)
- Cristian S Bernabe
- Department of Anatomy, Cellular Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Izabela F Caliman
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Aline R R de Abreu
- Departamento de Alimentos, Escola de Nutrição da Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | - Andrei I Molosh
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William A Truitt
- Department of Anatomy, Cellular Biology & Physiology, Indiana University School of Medicine, Indianapolis, IN, USA.
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA.
| | - Anantha Shekhar
- School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Philip L Johnson
- Department of Biology, University of South Dakota, Vermillion, SD, USA
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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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Higuchi Y, Tada T, Nakachi T, Arakawa H. Serotonergic circuit dysregulation underlying autism-related phenotypes in BTBR mouse model of autism. Neuropharmacology 2023:109634. [PMID: 37301467 DOI: 10.1016/j.neuropharm.2023.109634] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 06/05/2023] [Accepted: 06/08/2023] [Indexed: 06/12/2023]
Abstract
The inbred mouse strain, BTBR T+Itpr3tf/J (BTBR), possesses neuronal and circuit abnormalities that underlie atypical behavioral profiles resembling the major symptoms of human autism spectrum disorder (ASD). Forebrain serotonin (5-HT) transmission has been implicated in ASD-related behavioral alterations. In this study, we assessed 5-HT signals and the functional responsiveness in BTBR mice compared to standard C57BL/6J (B6) control mice to elucidate how 5-HT alterations contribute to behavioral abnormalities in BTBR mice. A lower number of 5-HT neurons in the median raphe, but not in the dorsal raphe, was observed in male and female BTBR mice. Acute systemic injection of buspirone, a 5-HT1A receptor agonist, induced c-Fos in several brain regions in both B6 and BTBR mice; however, blunted c-Fos induction in BTBR mice was documented in the cingulate cortex, basolateral amygdala (BLA), and ventral hippocampus (Hipp). Decreased c-Fos responses in these regions are associated with a lack of buspirone effects on anxiety-like behavior in BTBR mice. Analysis of mRNA expression following acute buspirone injection indicated that 5HTR1a gene downregulation (or upregulation) occurred in the BLA and Hipp of B6 mice, respectively, but not BTBR mice. The mRNA expression of factors associated with neurogenesis or the pro-inflammatory state was not consistently altered by acute buspirone injection. Therefore, 5-HT responsivity via 5-HT1A receptors in the BLA and Hipp are linked to anxiety-like behavior, in which circuits are disrupted in BTBR mice. Other distinct 5-HT circuits from the BLA and Hipp that regulate social behavior are restricted but preserved in BTBR mice.
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Affiliation(s)
- Yuki Higuchi
- Dept. Systems Physiology, Graduate School of Medicine, University of the Ryukyus, Japan
| | - Tomoaki Tada
- Dept. Systems Physiology, Faculty of Medicine, University of the Ryukyus, Japan
| | - Taiga Nakachi
- Dept. Systems Physiology, Faculty of Medicine, University of the Ryukyus, Japan
| | - Hiroyuki Arakawa
- Dept. Systems Physiology, Graduate School of Medicine, University of the Ryukyus, Japan.
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5
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Song J. Amygdala activity and amygdala-hippocampus connectivity: Metabolic diseases, dementia, and neuropsychiatric issues. Biomed Pharmacother 2023; 162:114647. [PMID: 37011482 DOI: 10.1016/j.biopha.2023.114647] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/04/2023] Open
Abstract
With rapid aging of the population worldwide, the number of people with dementia is dramatically increasing. Some studies have emphasized that metabolic syndrome, which includes obesity and diabetes, leads to increased risks of dementia and cognitive decline. Factors such as insulin resistance, hyperglycemia, high blood pressure, dyslipidemia, and central obesity in metabolic syndrome are associated with synaptic failure, neuroinflammation, and imbalanced neurotransmitter levels, leading to the progression of dementia. Due to the positive correlation between diabetes and dementia, some studies have called it "type 3 diabetes". Recently, the number of patients with cognitive decline due to metabolic imbalances has considerably increased. In addition, recent studies have reported that neuropsychiatric issues such as anxiety, depressive behavior, and impaired attention are common factors in patients with metabolic disease and those with dementia. In the central nervous system (CNS), the amygdala is a central region that regulates emotional memory, mood disorders, anxiety, attention, and cognitive function. The connectivity of the amygdala with other brain regions, such as the hippocampus, and the activity of the amygdala contribute to diverse neuropathological and neuropsychiatric issues. Thus, this review summarizes the significant consequences of the critical roles of amygdala connectivity in both metabolic syndromes and dementia. Further studies on amygdala function in metabolic imbalance-related dementia are needed to treat neuropsychiatric problems in patients with this type of dementia.
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Affiliation(s)
- Juhyun Song
- Department of Anatomy, Chonnam National University Medical School, Hwasun 58128, Jeollanam-do, Republic of Korea.
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6
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Fox LC, Scholl JL, Watt MJ, Forster GL. GABA A Receptor and Serotonin Transporter Expression Changes Dissociate Following Mild Traumatic Brain Injury: Influence of Sex and Estrus Cycle Phase in Rats. Neuroscience 2023; 514:38-55. [PMID: 36736883 DOI: 10.1016/j.neuroscience.2023.01.034] [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: 10/14/2022] [Revised: 01/20/2023] [Accepted: 01/26/2023] [Indexed: 02/04/2023]
Abstract
Mild traumatic brain injuries (mild TBIs) can affect both males and females, but females are more likely to report long-term psychological complications, including changes in mood and generalized anxiety. Additionally, reproductive cycle phase has been shown to affect mild TBI symptom expression within females. These variances may result from sex differences in mild TBI-induced alterations to neurotransmission in brain regions that influence mood and emotion, possibly mediated by sex steroids. The hippocampus and amygdala are implicated in stress responses and anxiety, and within these regions, gamma-aminobutyric acid (GABA) and serotonin modulate output and behavioral expression. Metabolites of progesterone can allosterically enhance GABAergic signaling, and sex steroids are suggested to regulate the expression of the serotonin transporter (SERT). To determine how mild TBI might alter GABA receptor and SERT expression in males and females, immunocytochemistry was used to quantify expression of the alpha-1 subunit of the GABAA receptor (α1-GABAA), SERT, and a neuronal marker (NeuN) in the brains of adult male and naturally-cycling female rats, both with and without mild TBI, 17 days after injury. Mild TBI altered the expression of α1-GABAA in the amygdala and hippocampus in both sexes, but the direction of change observed depended on sex and reproductive cycle phase. In contrast, mild TBI had little effect on SERT expression. However, SERT expression differed between sexes and varied with the cycle phase. These findings demonstrate that regulation of neurotransmission following mild TBI differs between males and females, with implications for behavioral outcomes and the efficacy of therapeutic strategies.
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Affiliation(s)
- Laura C Fox
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine at the University of South Dakota, 414 East Clark St, Vermillion, SD, USA.
| | - Jamie L Scholl
- Center for Brain and Behavior Research, Division of Basic Biomedical Sciences, Sanford School of Medicine at the University of South Dakota, 414 East Clark St, Vermillion, SD, USA.
| | - Michael J Watt
- Center for Brain and Behavior Research, Department of Anatomy, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
| | - Gina L Forster
- Center for Brain and Behavior Research, Department of Anatomy, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
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Yang C, Liao C, Zhao J, Guan Q, Wang G, Han Q. Dysregulation of tryptophan metabolism and distortion of cell signaling after oral exposure to ethanol and Kynurenic acid. Gene 2023; 852:147061. [PMID: 36423775 DOI: 10.1016/j.gene.2022.147061] [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: 08/29/2022] [Revised: 10/28/2022] [Accepted: 11/16/2022] [Indexed: 11/23/2022]
Abstract
Kynurenic acid (KYNA), an unavoidable tryptophan metabolite during fermentation is naturally blended with alcohol in all alcoholic beverages. Thus, alcohol drinking inevitably results in co-intake of KYNA. Effects of alcohol or KYNA on human health have been widely studied. However, the combined effects of both remain unknown. Here we report that alcohol and KYNA have a synergistic impact of on global gene expression, especially the gene sets related to tryptophan metabolism and cell signaling. Adult mice were exposed to alcohol (ethanol) and/or KYNA daily for a week. Transcriptomes of the brain, kidney and liver were profiled via bulk RNA sequencing. Results indicate that while KYNA alone largely promotes, and alcohol alone mostly inhibits gene expression, alcohol and KYNA co-administration has a stronger inhibition of global gene expression. Tryptophan metabolism is severely skewed towards kynurenine pathway by decreasing tryptophan hydroxylase 2 and increasing tryptophan dioxygenase. Quantification of tryptophan metabolic enzymes corroborates the transcriptional changes of these enzymes. Furthermore, the co-administration greatly enhances the GnRH signaling pathway. This research provides critical data to better understand the effects of alcohol and KYNA in mix on human health.
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Affiliation(s)
- Cihan Yang
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China.
| | - Chenghong Liao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
| | - Jianguo Zhao
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
| | - Qingfeng Guan
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
| | - Guoshun Wang
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA.
| | - Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, School of Life Sciences, Hainan University, Haikou, Hainan 570228, China; One Health Institute, Hainan University, Haikou, Hainan 570228, China.
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de Almeida C, Chabbah N, Eyraud C, Fasano C, Bernard V, Pietrancosta N, Fabre V, El Mestikawy S, Daumas S. Absence of VGLUT3 Expression Leads to Impaired Fear Memory in Mice. eNeuro 2023; 10:ENEURO.0304-22.2023. [PMID: 36720646 PMCID: PMC9953049 DOI: 10.1523/eneuro.0304-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 02/02/2023] Open
Abstract
Fear is an emotional mechanism that helps to cope with potential hazards. However, when fear is generalized, it becomes maladaptive and represents a core symptom of posttraumatic stress disorder (PTSD). Converging lines of research show that dysfunction of glutamatergic neurotransmission is a cardinal feature of trauma and stress related disorders such as PTSD. However, the involvement of glutamatergic co-transmission in fear is less well understood. Glutamate is accumulated into synaptic vesicles by vesicular glutamate transporters (VGLUTs). The atypical subtype, VGLUT3, is responsible for the co-transmission of glutamate with acetylcholine, serotonin, or GABA. To understand the involvement of VGLUT3-dependent co-transmission in aversive memories, we used a Pavlovian fear conditioning paradigm in VGLUT3-/- mice. Our results revealed a higher contextual fear memory in these mice, despite a facilitation of extinction. In addition, the absence of VGLUT3 leads to fear generalization, probably because of a pattern separation deficit. Our study suggests that the VGLUT3 network plays a crucial role in regulating emotional memories. Hence, VGLUT3 is a key player in the processing of aversive memories and therefore a potential therapeutic target in stress-related disorders.
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Affiliation(s)
- Camille de Almeida
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Nida Chabbah
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Camille Eyraud
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Caroline Fasano
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal QC H4H 1R3, Quebec, Canada
| | - Véronique Bernard
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Nicolas Pietrancosta
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Véronique Fabre
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
| | - Salah El Mestikawy
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
- Douglas Mental Health University Institute, Department of Psychiatry, McGill University, Montréal QC H4H 1R3, Quebec, Canada
| | - Stephanie Daumas
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Neuroscience Paris Seine - Institut de Biologie Paris Seine (NPS - IBPS), Paris 75005, France
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9
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Ronan PJ, Korzan WJ, Johnson PL, Lowry CA, Renner KJ, Summers CH. Prior stress and vasopressin promote corticotropin-releasing factor inhibition of serotonin release in the central nucleus of the amygdala. Front Behav Neurosci 2023; 17:1148292. [PMID: 37064300 PMCID: PMC10098171 DOI: 10.3389/fnbeh.2023.1148292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/15/2023] [Indexed: 04/18/2023] Open
Abstract
Corticotropin-releasing factor (CRF) is essential for coordinating endocrine and neural responses to stress, frequently facilitated by vasopressin (AVP). Previous work has linked CRF hypersecretion, binding site changes, and dysfunctional serotonergic transmission with anxiety and affective disorders, including clinical depression. Crucially, CRF can alter serotonergic activity. In the dorsal raphé nucleus and serotonin (5-HT) terminal regions, CRF effects can be stimulatory or inhibitory, depending on the dose, site, and receptor type activated. Prior stress alters CRF neurotransmission and CRF-mediated behaviors. Lateral, medial, and ventral subdivisions of the central nucleus of the amygdala (CeA) produce CRF and coordinate stress responsiveness. The purpose of these experiments was to determine the effect of intracerebroventricular (icv) administration of CRF and AVP on extracellular 5-HT as an index of 5-HT release in the CeA, using in vivo microdialysis in freely moving rats and high performance liquid chromatography (HPLC) analysis. We also examined the effect of prior stress (1 h restraint, 24 h prior) on CRF- and AVP-mediated release of 5-HT within the CeA. Our results show that icv CRF infusion in unstressed animals had no effect on 5-HT release in the CeA. Conversely, in rats with prior stress, CRF caused a profound dose-dependent decrease in 5-HT release within the CeA. This effect was long-lasting (240 min) and was mimicked by CRF plus AVP infusion without stress. Thus, prior stress and AVP functionally alter CRF-mediated neurotransmission and sensitize CRF-induced inhibition of 5-HT release, suggesting that this is a potential mechanism underlying stress-induced affective reactivity in humans.
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Affiliation(s)
- Patrick J. Ronan
- Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, United States
- Department of Psychiatry, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, United States
- Laboratory for Clinical and Translational Research in Psychiatry, Department of Veterans Affairs Medical Center, Denver, CO, United States
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Kenneth J. Renner,
| | - Wayne J. Korzan
- Department of Biological and Environmental Sciences, The University of West Alabama, Livingston, AL, United States
| | - Philip L. Johnson
- Department of Biology, University of South Dakota, Vermillion, SD, United States
| | - Christopher A. Lowry
- Department of Integrative Physiology, University of Colorado, Boulder, Boulder, CO, United States
| | - Kenneth J. Renner
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Department of Biology, University of South Dakota, Vermillion, SD, United States
- Patrick J. Ronan,
| | - Cliff H. Summers
- Research Service, Sioux Falls VA Health Care System, Sioux Falls, SD, United States
- Neuroscience Group, Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, United States
- Department of Biology, University of South Dakota, Vermillion, SD, United States
- *Correspondence: Cliff H. Summers,
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10
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Gowda SB, Banu A, Salim S, Peker KA, Mohammad F. Serotonin distinctly controls behavioral states in restrained and freely moving Drosophila. iScience 2022; 26:105886. [PMID: 36654863 PMCID: PMC9840979 DOI: 10.1016/j.isci.2022.105886] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 11/09/2022] [Accepted: 12/22/2022] [Indexed: 12/29/2022] Open
Abstract
When trapped in a physical restraint, animals must select an escape strategy to increase their chances of survival. After falling into an inescapable trap, they react with stereotypical behaviors that differ from those displayed in escapable situations. Such behaviors involve either a wriggling response to unlock the trap or feigning death to fend off a predator attack. The neural mechanisms that regulate animal behaviors have been well characterized for escapable situations but not for inescapable traps. We report that restrained vinegar flies exhibit alternating flailing and immobility to free themselves from the trap. We used optogenetics and intersectional genetic approaches to show that, while broader serotonin activation promotes immobility, serotonergic cells in the ventral nerve cord (VNC) regulate immobility states majorly via 5-HT7 receptors. Restrained and freely moving locomotor states are controlled by distinct mechanisms. Taken together, our study has identified serotonergic switches of the VNC that promote environment-specific adaptive behaviors.
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Affiliation(s)
- Swetha B.M. Gowda
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha 34110, Qatar
| | - Ayesha Banu
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha 34110, Qatar
| | - Safa Salim
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha 34110, Qatar
| | | | - Farhan Mohammad
- Division of Biological and Biomedical Sciences (BBS), College of Health & Life Sciences (CHLS), Hamad Bin Khalifa University (HBKU), Doha 34110, Qatar,Corresponding author
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11
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Yu XD, Zhu Y, Sun QX, Deng F, Wan J, Zheng D, Gong W, Xie SZ, Shen CJ, Fu JY, Huang H, Lai HY, Jin J, Li Y, Li XM. Distinct serotonergic pathways to the amygdala underlie separate behavioral features of anxiety. Nat Neurosci 2022; 25:1651-1663. [PMID: 36446933 DOI: 10.1038/s41593-022-01200-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/12/2022] [Indexed: 11/30/2022]
Abstract
Anxiety-like behaviors in mice include social avoidance and avoidance of bright spaces. Whether these features are distinctly regulated is unclear. We demonstrate that in mice, social and anxiogenic stimuli, respectively, increase and decrease serotonin (5-HT) levels in basal amygdala (BA). In dorsal raphe nucleus (DRN), 5-HT∩vGluT3 neurons projecting to BA parvalbumin (DRN5-HT∩vGluT3-BAPV) and pyramidal (DRN5-HT∩vGluT3-BAPyr) neurons have distinct intrinsic properties and gene expression and respond to anxiogenic and social stimuli, respectively. Activation of DRN5-HT∩vGluT3→BAPV inhibits 5-HT release via GABAB receptors on serotonergic terminals in BA, inducing social avoidance and avoidance of bright spaces. Activation of DRN5-HT∩vGluT3→BA neurons inhibits two subsets of BAPyr neurons via 5-HT1A receptors (HTR1A) and 5-HT1B receptors (HTR1B). Pharmacological inhibition of HTR1A and HTR1B in BA induces avoidance of bright spaces and social avoidance, respectively. These findings highlight the functional significance of heterogenic inputs from DRN to BA subpopulations in the regulation of separate anxiety-related behaviors.
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Affiliation(s)
- Xiao-Dan Yu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China.,Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China
| | - Yi Zhu
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Qi-Xin Sun
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Fei Deng
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Jinxia Wan
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Di Zheng
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Wankun Gong
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shi-Ze Xie
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Chen-Jie Shen
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Jia-Yu Fu
- NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China
| | - Huiqian Huang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Hsin-Yi Lai
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.,Department of Neurology of the Second Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, China.,College of Biomedical Engineering and Instrument Science, Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China.,Affiliated Mental Health Center & Hangzhou Seventh People's Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Jin Jin
- The MOE Key Laboratory of Biosystems Homeostasis & Protection, Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, Peking University School of Life Sciences, Beijing, China
| | - Xiao-Ming Li
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China. .,NHC and CAMS Key Laboratory of Medical Neurobiology, MOE Frontier Center of Brain Science and Brain-machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, China. .,Center for Brain Science and Brain-Inspired Intelligence, Research Units for Emotion and Emotion Disorders, Chinese Academy of Medical Sciences/Guangdong-Hong Kong-Macao Greater Bay Area Center for Brain Science and Brain-Inspired Intelligence, Guangzhou, China.
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12
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Kusek M, Siwiec M, Sowa JE, Bobula B, Bilecki W, Ciurej I, Kaczmarczyk M, Kowalczyk T, Maćkowiak M, Hess G, Tokarski K. 5-HT 7 receptors enhance inhibitory synaptic input to principal neurons in the mouse basal amygdala. Neuropharmacology 2021; 198:108779. [PMID: 34481835 DOI: 10.1016/j.neuropharm.2021.108779] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/06/2021] [Accepted: 08/27/2021] [Indexed: 11/15/2022]
Abstract
The basal amygdala (BA) has been implicated in encoding fear and its extinction. The level of serotonin (5-HT) in the BA increases due to arousal and stress related to aversive stimuli. The effects of 5-HT7 receptor (5-HT7R) activation and blockade on the activity of BA neurons have not yet been investigated. In the present study, a transgenic mouse line carrying green fluorescent protein (GFP) reporter gene was used to identify neurons that express the 5-HT7R. GFP immunoreactivity was present mainly in cells that also expressed GAD67 or parvalbumin (PV), the phenotypic markers for GABAergic interneurons. Most cells showing GFP fluorescence demonstrated firing patterns characteristic of BA inhibitory interneurons. Activation of 5-HT7Rs resulted in a depolarization and/or occurrence of spontaneous spiking activity of BA interneurons that was accompanied by an increase in the mean frequency and mean amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) recorded from BA principal neurons. These effects were blocked by a specific 5-HT7R antagonist, SB269970 and were absent in slices from 5-HT7R knockout mice. Activation of 5-HT7Rs also decreased the mean frequency of spontaneous excitatory postsynaptic currents (sEPSCs) recorded from BA principal neurons, which was blocked by the GABAA receptor antagonist picrotoxin. Neither inhibitory nor excitatory miniature postsynaptic currents (mIPSCs/mEPSCs) were affected by 5-HT7R activation. These results show that in the BA 5-HT7Rs stimulate an activity-dependent enhancement of inhibitory input from local interneurons to BA principal neurons and provide insights about the possible involvement of BA serotonergic receptors in neuronal mechanisms underlying fear memory.
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Affiliation(s)
- Magdalena Kusek
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Marcin Siwiec
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Joanna Ewa Sowa
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Bartosz Bobula
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Wiktor Bilecki
- Laboratory of Pharmacology and Brain Biostructure, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Izabela Ciurej
- Institute of Zoology and Biomedical Research, Jagiellonian University, Gronostajowa 9 Str., 30-387, Kraków, Poland
| | - Maria Kaczmarczyk
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Tomasz Kowalczyk
- Department of Neurobiology, University of Łódź, Pomorska Str. No 141/143, 91-236, Łódź, Poland
| | - Marzena Maćkowiak
- Laboratory of Pharmacology and Brain Biostructure, Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland
| | - Grzegorz Hess
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland.
| | - Krzysztof Tokarski
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12 Str., 31-343, Kraków, Poland.
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13
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Abstract
OBJECTIVE Whereas numerous experimental and clinical studies suggest a complex involvement of serotonin in the regulation of anxiety, it remains to be clarified if the dominating impact of this transmitter is best described as anxiety-reducing or anxiety-promoting. The aim of this study was to assess the impact of serotonin depletion on acquisition, consolidation, and expression of conditioned fear. METHODS Male Sprague-Dawley rats were exposed to foot shocks as unconditioned stimulus and assessed with respect to freezing behaviour when re-subjected to context. Serotonin depletion was achieved by administration of a serotonin synthesis inhibitor, para-chlorophenylalanine (PCPA) (300 mg/kg daily × 3), (i) throughout the period from (and including) acquisition to (and including) expression, (ii) during acquisition but not expression, (iii) after acquisition only, and (iv) during expression only. RESULTS The time spent freezing was significantly reduced in animals that were serotonin-depleted during the entire period from (and including) acquisition to (and including) expression, as well as in those being serotonin-depleted during either acquisition only or expression only. In contrast, PCPA administrated immediately after acquisition, that is during memory consolidation, did not impact the expression of conditioned fear. CONCLUSION Intact serotonergic neurotransmission is important for both acquisition and expression of context-conditioned fear.
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14
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Awasthi JR, Tamada K, Overton ETN, Takumi T. Comprehensive topographical map of the serotonergic fibers in the male mouse brain. J Comp Neurol 2021; 529:1391-1429. [PMID: 32892368 DOI: 10.1002/cne.25027] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 08/14/2020] [Accepted: 08/26/2020] [Indexed: 11/11/2022]
Abstract
It is well established that serotonergic fibers distribute throughout the brain. Abnormal densities or patterns of serotonergic fibers have been implicated in neuropsychiatric disorders. Although many classical studies have examined the distribution pattern of serotonergic fibers, most of them were either limited to specific brain areas or had limitations in demonstrating the fine axonal morphology. In this study, we utilize male mice expressing green fluorescence protein under the serotonin transporter (SERT) promoter to map the topography of serotonergic fibers across the rostro-caudal extent of each brain area. We demonstrate previously unreported regional density and fine-grained anatomy of serotonergic fibers. Our findings include: (a) SERT fibers distribute abundantly in the thalamic nuclei close to the midline and dorsolateral areas, in most of the hypothalamic nuclei with few exceptions such as the median eminence and arcuate nuclei, and within the basal amygdaloid complex and lateral septal nuclei, (b) the source fibers of innervation of the hippocampus traverse through the septal nuclei before reaching its destination, (c) unique, filamentous type of straight terminal fibers within the nucleus accumbens, (d) laminar pattern of innervation in the hippocampus, olfactory bulb and cortex with heterogenicity in innervation density among the layers, (e) cortical labeling density gradually decreases rostro-caudally, (f) fibers traverse and distribute mostly within the gray matter, leaving the white fiber bundles uninnervated, and (g) most of the highly labeled nuclei and cortical areas have predominant anatomical connection to limbic structures. In conclusion, we provide novel, regionally specific insights on the distribution map of serotonergic fibers using transgenic mouse.
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Affiliation(s)
- Janak R Awasthi
- RIKEN Brain Science Institute, Wako, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | | | | | - Toru Takumi
- RIKEN Brain Science Institute, Wako, Japan.,Graduate School of Science and Engineering, Saitama University, Saitama, Japan.,Department of Physiology and Cell Biology, Kobe University School of Medicine, Kobe, Japan
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15
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Pereyra AE, Mininni CJ, Zanutto BS. Serotonergic modulation of basolateral amygdala nucleus in the extinction of reward-driven learning: The role of 5-HT bioavailability and 5-HT 1A receptor. Behav Brain Res 2021; 404:113161. [PMID: 33571570 DOI: 10.1016/j.bbr.2021.113161] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 01/15/2021] [Accepted: 01/31/2021] [Indexed: 12/29/2022]
Abstract
Serotonin (5-HT) neurotransmission has been associated with reward-related behaviour. Moreover, the serotonergic system modulates the basolateral amygdala (BLA), a structure involved in reward encoding, and reward prediction error. However, the role played by 5-HT on BLA during a reward-driven task has not been fully elucidated. In this paper, we investigated whether serotonergic modulation of the BLA is involved in reward-driven learning. To this end, we trained Long Evans rats in an operant conditioning task, and examined the effects of fluoxetine treatment (a selective serotonin reuptake inhibitor, 10 mg/kg) in combination with BLA lesions with NMDA (20 mg/mL) on extinction learning. We also investigated whether intra-BLA injection of the serotonergic 5-HT1A receptor agonist 8-OH DPAT, or antagonist WAY-100635, alters extinction performance. We found that fluoxetine treatment strongly accelerated extinction learning, while BLA lesions partially reverted this effect and slightly impaired consolidation of extinction. Stimulation and inhibition of 5-HT1A receptors in BLA induced opposite effects to those of fluoxetine, impairing or accelerating extinction performance, respectively. Our findings suggest that 5-HT modulates reward-driven learning, and 5-HT1A receptors located in the BLA are relevant for extinction.
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Affiliation(s)
- A Ezequiel Pereyra
- Instituto de Biologı́a y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, CABA, Argentina.
| | - Camilo J Mininni
- Instituto de Biologı́a y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, CABA, Argentina; Universidad de Buenos Aires, Facultad de Ingenierı́a, Instituto de Ingenierı́a Biomédica (IIBM), CABA, Argentina.
| | - B Silvano Zanutto
- Instituto de Biologı́a y Medicina Experimental (IBYME-CONICET), Vuelta de Obligado 2490, CABA, Argentina; Universidad de Buenos Aires, Facultad de Ingenierı́a, Instituto de Ingenierı́a Biomédica (IIBM), CABA, Argentina.
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16
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Ferri SL, Dow HC, Schoch H, Lee JY, Brodkin ES, Abel T. Age- and sex-specific fear conditioning deficits in mice lacking Pcdh10, an Autism Associated Gene. Neurobiol Learn Mem 2020; 178:107364. [PMID: 33340671 DOI: 10.1016/j.nlm.2020.107364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/21/2020] [Accepted: 11/14/2020] [Indexed: 02/07/2023]
Abstract
PCDH10 is a gene associated with Autism Spectrum Disorder. It is involved in the growth of thalamocortical projections and dendritic spine elimination. Previously, we characterized Pcdh10 haploinsufficient mice (Pcdh10+/- mice) and found male-specific social deficits and dark phase hypoactivity. Pcdh10+/- males exhibit increased dendritic spine density of immature morphology, decreased NMDAR expression, and decreased gamma synchronization in the basolateral amygdala (BLA). Here, we further characterize Pcdh10+/- mice by testing for fear memory, which relies on BLA function. We used both male and female Pcdh10+/- mice and their wild-type littermates at two ages, juvenile and adult, and in two learning paradigms, cued and contextual fear conditioning. We found that males at both ages and in both assays exhibited fear conditioning deficits, but females were only impaired as adults in the cued condition. These data are further evidence for male-specific alterations in BLA-related behaviors in Pcdh10+/- mice and suggest that these mice may be a useful model for dissecting male specific brain and behavioral phenotypes relevant to social and emotional behaviors.
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Affiliation(s)
- Sarah L Ferri
- Iowa Neuroscience Institute, Department of Neuroscience and Pharmacology, University of Iowa, 169 Newton Road, 2312 Pappajohn Biomedical Discovery Building, Iowa City, IA 52242, USA
| | - Holly C Dow
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31(st) Street, Room 2202, Philadelphia, PA 19104-3403, USA
| | - Hannah Schoch
- Department of Biomedical Sciences, Elson S. Floyd College of Medicine, Washington State University, 412 E. Spokane Falls Blvd., Spokane, WA, 99202, USA
| | - Ji Youn Lee
- Iowa Neuroscience Institute, Department of Neuroscience and Pharmacology, University of Iowa, 169 Newton Road, 2312 Pappajohn Biomedical Discovery Building, Iowa City, IA 52242, USA
| | - Edward S Brodkin
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Translational Research Laboratory, 125 South 31(st) Street, Room 2202, Philadelphia, PA 19104-3403, USA
| | - Ted Abel
- Iowa Neuroscience Institute, Department of Neuroscience and Pharmacology, University of Iowa, 169 Newton Road, 2312 Pappajohn Biomedical Discovery Building, Iowa City, IA 52242, USA.
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17
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Inactivation of the GATA Cofactor ZFPM1 Results in Abnormal Development of Dorsal Raphe Serotonergic Neuron Subtypes and Increased Anxiety-Like Behavior. J Neurosci 2020; 40:8669-8682. [PMID: 33046550 DOI: 10.1523/jneurosci.2252-19.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 09/17/2020] [Accepted: 09/25/2020] [Indexed: 12/14/2022] Open
Abstract
Serotonergic neurons in the dorsal raphe (DR) nucleus are associated with several psychiatric disorders including depression and anxiety disorders, which often have a neurodevelopmental component. During embryonic development, GATA transcription factors GATA2 and GATA3 operate as serotonergic neuron fate selectors and regulate the differentiation of serotonergic neuron subtypes of DR. Here, we analyzed the requirement of GATA cofactor ZFPM1 in the development of serotonergic neurons using Zfpm1 conditional mouse mutants. Our results demonstrated that, unlike the GATA factors, ZFPM1 is not essential for the early differentiation of serotonergic precursors in the embryonic rhombomere 1. In contrast, in perinatal and adult male and female Zfpm1 mutants, a lateral subpopulation of DR neurons (ventrolateral part of the DR) was lost, whereas the number of serotonergic neurons in a medial subpopulation (dorsal region of the medial DR) had increased. Additionally, adult male and female Zfpm1 mutants had reduced serotonin concentration in rostral brain areas and displayed increased anxiety-like behavior. Interestingly, female Zfpm1 mutant mice showed elevated contextual fear memory that was abolished with chronic fluoxetine treatment. Altogether, these results demonstrate the importance of ZFPM1 for the development of DR serotonergic neuron subtypes involved in mood regulation. It also suggests that the neuronal fate selector function of GATAs is modulated by their cofactors to refine the differentiation of neuronal subtypes.SIGNIFICANCE STATEMENT Predisposition to anxiety disorders has both a neurodevelopmental and a genetic basis. One of the brainstem nuclei involved in the regulation of anxiety is the dorsal raphe, which contains different subtypes of serotonergic neurons. We show that inactivation of a transcriptional cofactor ZFPM1 in mice results in a developmental failure of laterally located dorsal raphe serotonergic neurons and changes in serotonergic innervation of rostral brain regions. This leads to elevated anxiety-like behavior and contextual fear memory, alleviated by chronic fluoxetine treatment. Our work contributes to understanding the neurodevelopmental mechanisms that may be disturbed in the anxiety disorder.
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18
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Knight CP, Hauser SR, Waeiss RA, Molosh AI, Johnson PL, Truitt WA, McBride WJ, Bell RL, Shekhar A, Rodd ZA. The Rewarding and Anxiolytic Properties of Ethanol within the Central Nucleus of the Amygdala: Mediated by Genetic Background and Nociceptin. J Pharmacol Exp Ther 2020; 374:366-375. [PMID: 32527792 PMCID: PMC7430446 DOI: 10.1124/jpet.119.262097] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 04/15/2020] [Indexed: 01/20/2023] Open
Abstract
In humans, alcohol is consumed for its rewarding and anxiolytic effects. The central nucleus of the amygdala (CeA) is considered a neuronal nexus that regulates fear, anxiety, and drug self-administration. Manipulations of the CeA alter ethanol (EtOH) consumption under numerous EtOH self-administration models. The experiments determined whether EtOH is reinforcing/anxiolytic within the CeA, whether selective breeding for high alcohol consumption alters the rewarding properties of EtOH in the CeA, and whether the reinforcing/anxiolytic effects of EtOH in the CeA are mediated by the neuropeptides corticotropin-releasing factor (CRF) and nociceptin. The reinforcing properties of EtOH were determined by having male Wistar and Taconic alcohol-preferring (tP) rats self-administer EtOH directly into the CeA. The expression of anxiety-like behaviors was assessed through multiple behavioral models (social interaction, acoustic startle, and open field). Coadministration of EtOH and a CRF1 antagonist (NBI35965) or nociceptin on self-administration into the CeA and anxiety-like behaviors was determined. EtOH was self-administered directly into the lateral CeA, and tP rats self-administered a lower concentration of EtOH than Wistar rats. EtOH microinjected into the lateral CeA reduced the expression of anxiety-like behaviors, indicating an anxiolytic effect. Coadministration of NBI35965 failed to alter the rewarding/anxiolytic properties of EtOH in the CeA. In contrast, coadministration of the nociceptin enhanced both EtOH reward and anxiolysis in the CeA. Overall, the data indicate that the lateral CeA is a key anatomic location that mediates the rewarding and anxiolytic effects of EtOH, and local nociceptin receptors, but not local CRF1 receptors, are involved in these behaviors. SIGNIFICANCE STATEMENT: Alcohol is consumed for the stimulatory, rewarding, and anxiolytic properties of the drug of abuse. The current data are the first to establish that alcohol is reinforcing and anxiolytic within the lateral central nucleus of the amygdala (CeA) and that the nociceptin system regulates these effects of alcohol within the CeA.
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Affiliation(s)
- Christopher P Knight
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Sheketha R Hauser
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - R Aaron Waeiss
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Andrei I Molosh
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Philip L Johnson
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - William A Truitt
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - William J McBride
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Anantha Shekhar
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Zachary A Rodd
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana
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19
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Sugiyama E, Skelly AN, Suematsu M, Sugiura Y. In situ imaging of monoamine localization and dynamics. Pharmacol Ther 2020; 208:107478. [DOI: 10.1016/j.pharmthera.2020.107478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 11/22/2019] [Indexed: 01/06/2023]
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20
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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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Deryabina IB, Andrianov VV, Muranova LN, Bogodvid TK, Gainutdinov KL. Effects of Thryptophan Hydroxylase Blockade by P-Chlorophenylalanine on Contextual Memory Reconsolidation after Training of Different Intensity. Int J Mol Sci 2020; 21:E2087. [PMID: 32197439 PMCID: PMC7139692 DOI: 10.3390/ijms21062087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/13/2020] [Accepted: 03/16/2020] [Indexed: 01/09/2023] Open
Abstract
The processes of memory formation and its storage are extremely dynamic. Therefore, the determination of the nature and temporal evolution of the changes that underlie the molecular mechanisms of retrieval and cause reconsolidation of memory is the key to understanding memory formation. Retrieval induces the plasticity, which may result in reconsolidation of the original memory and needs critical molecular events to stabilize the memory or its extinction. 4-Chloro-DL-phenylalanine (P-chlorophenylalanine-PCPA) depresses the most limiting enzyme of serotonin synthesis the tryptophan hydroxylase. It is known that PCPA reduces the serotonin content in the brain up to 10 times in rats (see Methods). We hypothesized that the PCPA could behave the similar way in snails and could reduce the content of serotonin in snails. Therefore, we investigated the effect of PCPA injection on contextual memory reconsolidation using a protein synthesis blocker in snails after training according to two protocols of different intensities. The results obtained in training according to the first protocol using five electrical stimuli per day for 5 days showed that reminding the training environment against the background of injection of PCPA led to a significant decrease in contextual memory. At the same time, the results obtained in training according to the second protocol using three electrical stimuli per day for 5 days showed that reminding the training environment against the injection of PCPA did not result in a significant change in contextual memory. The obtain results allowed us to conclude that the mechanisms of processes developed during the reconsolidation of contextual memory after a reminding depend both on the intensity of learning and on the state of the serotonergic system.
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Affiliation(s)
- Irina B. Deryabina
- Laboratory of Neuroreabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420000 Kazan, Russia; (I.B.D.); (V.V.A.); (L.N.M.); (T.K.B.)
| | - Viatcheslav V. Andrianov
- Laboratory of Neuroreabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420000 Kazan, Russia; (I.B.D.); (V.V.A.); (L.N.M.); (T.K.B.)
- Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of Sciences, 420000 Kazan, Russia
| | - Lyudmila N. Muranova
- Laboratory of Neuroreabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420000 Kazan, Russia; (I.B.D.); (V.V.A.); (L.N.M.); (T.K.B.)
| | - Tatiana K. Bogodvid
- Laboratory of Neuroreabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420000 Kazan, Russia; (I.B.D.); (V.V.A.); (L.N.M.); (T.K.B.)
- Department of Biomedical Sciences, Volga Region State Academy of Physical Culture, Sport and Tourism, 420000 Kazan, Russia
| | - Khalil L. Gainutdinov
- Laboratory of Neuroreabilitation of Motor Disorders, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420000 Kazan, Russia; (I.B.D.); (V.V.A.); (L.N.M.); (T.K.B.)
- Laboratory of Spin Physics and Spin Chemistry, Zavoisky Physical-Technical Institute of the Russian Academy of Sciences, 420000 Kazan, Russia
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Xu Y, Cantwell L, Molosh AI, Plant LD, Gazgalis D, Fitz SD, Dustrude ET, Yang Y, Kawano T, Garai S, Noujaim SF, Shekhar A, Logothetis DE, Thakur GA. The small molecule GAT1508 activates brain-specific GIRK1/2 channel heteromers and facilitates conditioned fear extinction in rodents. J Biol Chem 2020; 295:3614-3634. [PMID: 31953327 DOI: 10.1074/jbc.ra119.011527] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/09/2020] [Indexed: 01/31/2023] Open
Abstract
G-protein-gated inwardly-rectifying K+ (GIRK) channels are targets of Gi/o-protein-signaling systems that inhibit cell excitability. GIRK channels exist as homotetramers (GIRK2 and GIRK4) or heterotetramers with nonfunctional homomeric subunits (GIRK1 and GIRK3). Although they have been implicated in multiple conditions, the lack of selective GIRK drugs that discriminate among the different GIRK channel subtypes has hampered investigations into their precise physiological relevance and therapeutic potential. Here, we report on a highly-specific, potent, and efficacious activator of brain GIRK1/2 channels. Using a chemical screen and electrophysiological assays, we found that this activator, the bromothiophene-substituted small molecule GAT1508, is specific for brain-expressed GIRK1/2 channels rather than for cardiac GIRK1/4 channels. Computational models predicted a GAT1508-binding site validated by experimental mutagenesis experiments, providing insights into how urea-based compounds engage distant GIRK1 residues required for channel activation. Furthermore, we provide computational and experimental evidence that GAT1508 is an allosteric modulator of channel-phosphatidylinositol 4,5-bisphosphate interactions. Through brain-slice electrophysiology, we show that subthreshold GAT1508 concentrations directly stimulate GIRK currents in the basolateral amygdala (BLA) and potentiate baclofen-induced currents. Of note, GAT1508 effectively extinguished conditioned fear in rodents and lacked cardiac and behavioral side effects, suggesting its potential for use in pharmacotherapy for post-traumatic stress disorder. In summary, our findings indicate that the small molecule GAT1508 has high specificity for brain GIRK1/2 channel subunits, directly or allosterically activates GIRK1/2 channels in the BLA, and facilitates fear extinction in a rodent model.
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Affiliation(s)
- Yu Xu
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Lucas Cantwell
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Andrei I Molosh
- Department of Psychiatry, Paul and Carole Stark Neurosciences Research Institute, Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Dimitris Gazgalis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Stephanie D Fitz
- Department of Psychiatry, Paul and Carole Stark Neurosciences Research Institute, Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Erik T Dustrude
- Department of Psychiatry, Paul and Carole Stark Neurosciences Research Institute, Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Yuchen Yang
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Takeharu Kawano
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Sumanta Garai
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115
| | - Sami F Noujaim
- Molecular Pharmacology and Physiology, University of South Florida, Tampa, Florida 33612
| | - Anantha Shekhar
- Department of Psychiatry, Paul and Carole Stark Neurosciences Research Institute, Indiana Clinical and Translational Sciences Institute, Indiana University School of Medicine, Indianapolis, Indiana 46202.
| | - Diomedes E Logothetis
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115.
| | - Ganesh A Thakur
- Department of Pharmaceutical Sciences, School of Pharmacy, Bouvé College of Health Sciences, and Center for Drug Discovery, Northeastern University, Boston, Massachusetts 02115.
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Treatment with a heat-killed preparation of Mycobacterium vaccae after fear conditioning enhances fear extinction in the fear-potentiated startle paradigm. Brain Behav Immun 2019; 81:151-160. [PMID: 31175996 PMCID: PMC6754802 DOI: 10.1016/j.bbi.2019.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 12/11/2022] Open
Abstract
The hygiene hypothesis or "Old Friends" hypothesis proposes that inflammatory diseases are increasing in modern urban societies, due in part to reduced exposure to microorganisms that drive immunoregulatory circuits and a failure to terminate inappropriate inflammatory responses. Inappropriate inflammation is also emerging as a risk factor for anxiety disorders, affective disorders, and trauma-and stressor-related disorders, including posttraumatic stress disorder (PTSD), which is characterized as persistent re-experiencing of the trauma after a traumatic experience. Traumatic experiences can lead to long-lasting fear memories and fear potentiation of the acoustic startle reflex. The acoustic startle reflex is an ethologically relevant reflex and can be potentiated in both humans and rats through Pavlovian conditioning. Mycobacterium vaccae is a soil-derived bacterium with immunoregulatory and anti-inflammatory properties that has been demonstrated to enhance fear extinction in the fear-potentiated startle paradigm when given prior to fear conditioning. To determine if immunization with M. vaccae after fear conditioning also has protective effects, adult male Sprague Dawley rats underwent fear conditioning on days -37 and -36 followed by immunizations (3x), once per week beginning 24 h following fear conditioning, with a heat-killed preparation of M. vaccae NCTC 11659 (0.1 mg, s.c., in 100 µl borate-buffered saline) or vehicle, and, then, 3 weeks following the final immunization, were tested in the fear-potentiated startle paradigm (n = 12 per group). Rats underwent fear extinction training on days 1 through 6 followed by spontaneous recovery 14 days later (day 20). Rats were euthanized on day 21 and brain tissue was sectioned for analysis of Tph2, Htr1a, Slc6a4, Slc22a3, and Crhr2 mRNA expression throughout the brainstem dorsal and median raphe nuclei. Immunization with M. vaccae did not affect fear expression on day 1. However, M. vaccae-immunized rats showed enhanced enhanced within-session fear extinction on day 1 and enhanced between-session fear extinction beginning on day 2, relative to vehicle-immunized controls. Immunization with M. vaccae and fear-potentiated startle had minimal effects on serotonergic gene expression when assessed 42 days after the final immunization. Together with previous studies, these data are consistent with the hypothesis that immunoregulatory strategies, such as immunization with M. vaccae, have potential for both prevention and treatment of trauma- and stressor-related psychiatric disorders.
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de Assis Brasil ES, Guerino Furini CR, da Silva Rodrigues F, Nachtigall EG, Kielbovicz Behling JA, Saenger BF, Farias CP, de Carvalho Myskiw J, Izquierdo I. The blockade of the serotoninergic receptors 5-HT5A, 5-HT6 and 5-HT7 in the basolateral amygdala, but not in the hippocampus facilitate the extinction of fear memory. Behav Brain Res 2019; 372:112055. [DOI: 10.1016/j.bbr.2019.112055] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/27/2019] [Accepted: 06/20/2019] [Indexed: 01/20/2023]
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25
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Sugiyama E, Guerrini MM, Honda K, Hattori Y, Abe M, Källback P, Andrén PE, Tanaka KF, Setou M, Fagarasan S, Suematsu M, Sugiura Y. Detection of a High-Turnover Serotonin Circuit in the Mouse Brain Using Mass Spectrometry Imaging. iScience 2019; 20:359-372. [PMID: 31614319 PMCID: PMC6818351 DOI: 10.1016/j.isci.2019.09.036] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 07/12/2019] [Accepted: 09/24/2019] [Indexed: 12/31/2022] Open
Abstract
Monoamine neurotransmitters are released by specialized neurons regulating behavioral, motor, and cognitive functions. Although the localization of monoaminergic neurons in the brain is well known, the distribution and kinetics of monoamines remain unclear. Here, we generated a murine brain atlas of serotonin (5-HT), dopamine (DA), and norepinephrine (NE) levels using mass spectrometry imaging (MSI). We found several nuclei rich in both 5-HT and a catecholamine (DA or NE) and identified the paraventricular nucleus of the thalamus (PVT), where 5-HT and NE are co-localized. The analysis of 5-HT fluctuations in response to acute tryptophan depletion and infusion of isotope-labeled tryptophan in vivo revealed a close kinetic association between the raphe nuclei, PVT, and amygdala but not the other nuclei. Our findings imply the existence of a highly dynamic 5-HT-mediated raphe to PVT pathway that likely plays a role in the brain monoamine system. A murine brain atlas of monoamine (5-HT, DA, NE) levels was generated via MS imaging We identified several nuclei rich in both 5-HT and a catecholamine (DA or NE) The paraventricular nucleus of the thalamus (PVT) had high levels of 5-HT and NE The level of 5-HT in raphe to PVT pathway changed dynamically in response to blood Trp level
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Affiliation(s)
- Eiji Sugiyama
- Department of Biochemistry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Matteo M Guerrini
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences, RIKEN Yokohama Institute, Tsurumi Ward, Suehirocho, 1 Chome-7-22, Yokohama, Kanagawa Prefecture 230-0045, Japan
| | - Kurara Honda
- Department of Biochemistry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Yuko Hattori
- Department of Biochemistry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Manabu Abe
- Department of Animal Model Development, Brain Research Institute, Niigata University, 1-757 Asahimachi-dori, Chuo-ku, Niigata 951-8585, Japan
| | - Patrik Källback
- Medical Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences, Uppsala University, Box 591 BMC, 75124 Uppsala, Sweden; Science for Life Laboratory, National Resource for Mass Spectrometry Imaging, Uppsala University, Box 591 BMC, 75124 Uppsala, Sweden
| | - Per E Andrén
- Medical Mass Spectrometry Imaging, Department of Pharmaceutical Biosciences, Uppsala University, Box 591 BMC, 75124 Uppsala, Sweden; Science for Life Laboratory, National Resource for Mass Spectrometry Imaging, Uppsala University, Box 591 BMC, 75124 Uppsala, Sweden
| | - Kenji F Tanaka
- Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Mitsutoshi Setou
- Department of Cellular and Molecular Anatomy and International Mass Imaging Center, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu, Shizuoka 431-3192, Japan
| | - Sidonia Fagarasan
- Laboratory for Mucosal Immunity, Center for Integrative Medical Sciences, RIKEN Yokohama Institute, Tsurumi Ward, Suehirocho, 1 Chome-7-22, Yokohama, Kanagawa Prefecture 230-0045, Japan
| | - Makoto Suematsu
- Department of Biochemistry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan
| | - Yuki Sugiura
- Department of Biochemistry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo 160-8582, Japan.
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26
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Waeiss RA, Knight CP, Carvajal GB, Bell RL, Engleman EA, McBride WJ, Hauser SR, Rodd ZA. Peri-adolescent alcohol consumption increases sensitivity and dopaminergic response to nicotine during adulthood in female alcohol-preferring (P) rats: Alterations to α7 nicotinic acetylcholine receptor expression. Behav Brain Res 2019; 376:112190. [PMID: 31473285 DOI: 10.1016/j.bbr.2019.112190] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/05/2019] [Accepted: 08/28/2019] [Indexed: 12/11/2022]
Abstract
Adolescent alcohol drinking has been linked to increased risk for drug abuse during adulthood. Nicotine microinjected directly into the posterior ventral tegmental area (pVTA) stimulates dopamine (DA) release in the nucleus accumbens (NAc) shell. The α7 nicotinic acetylcholine receptor (nAChR) is a potent regulator of dopaminergic activity in the pVTA. The current experiments examined the effects of peri-adolescent ethanol (EtOH) drinking on the ability of intra-pVTA nicotine to stimulate DA release during adulthood and alterations in α7 nAChR expression within the pVTA. Alcohol-preferring (P) female rats consumed EtOH and/or water during adolescence (post-natal day [PND] 30-60) or adulthood (PND 90-120). Thirty days following removal of EtOH, subjects received microinjections of 1 μM, 10 μM, or 50 μM nicotine into the pVTA concurrently with microdialysis for extracellular DA in the NAc shell. Brains were harvested from an additional cohort after PND 90 for quantification of α7 nAChR within the pVTA. The results indicated that only adolescent EtOH consumption produced a leftward and upward shift in the dose response curve for nicotine to stimulate DA release in the NAc shell. Investigation of α7 nAChR expression within the pVTA revealed a significant increase in animals that consumed EtOH during adolescence compared to naïve animals. The data suggests that peri-adolescent EtOH consumption produced cross-sensitization to the effects of nicotine during adulthood. The interaction between adolescent EtOH consumption and inflated adult risk for drug dependency could be predicated, at least in part, upon alterations in α7 nAChR expression within the mesolimbic reward pathway.
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Affiliation(s)
- Robert A Waeiss
- Program in Medical Neuroscience, Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States.
| | - Christopher P Knight
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Gustavo B Carvajal
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Richard L Bell
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Eric A Engleman
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - William J McBride
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Sheketha R Hauser
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
| | - Zachary A Rodd
- Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN, 46202, United States; Paul and Carole Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
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27
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Sengupta A, Holmes A. A Discrete Dorsal Raphe to Basal Amygdala 5-HT Circuit Calibrates Aversive Memory. Neuron 2019; 103:489-505.e7. [PMID: 31204082 DOI: 10.1016/j.neuron.2019.05.029] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 02/14/2019] [Accepted: 05/15/2019] [Indexed: 11/26/2022]
Abstract
Despite a wealth of clinical and preclinical data implicating the serotonin (5-HT) system in fear-related affective disorders, a precise definition of this neuromodulator's role in fear remains elusive. Using convergent anatomical and functional approaches, we interrogate the contribution to fear of basal amygdala (BA) 5-HT inputs from the dorsal raphe nucleus (DRN). We show the DRN→BA 5-HT pathway is engaged during fear memory formation and retrieval, and activity of these projections facilitates fear and impairs extinction. The DRN→BA 5-HT pathway amplifies fear-associated BA neuronal firing and theta power and phase-locking. Although fear recruits 5-HT and VGluT3 co-expressing DRN neurons, the fear-potentiating influence of the DRN→BA 5-HT pathway requires signaling at BA 5-HT1A/2A receptors. Input-output mapping illustrates how the DRN→BA 5-HT pathway is anatomically distinct and connected with other brain regions that mediate fear. These findings reveal how a discrete 5-HT circuit orchestrates a broader neural network to calibrate aversive memory.
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Affiliation(s)
- Ayesha Sengupta
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA.
| | - Andrew Holmes
- Laboratory of Behavioral and Genomic Neuroscience, National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA.
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28
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de Paula BB, de Melo JR, Leite-Panissi CRA. Modulation of tonic immobility by GABAA and GABAB receptors of the medial amygdala. Neurosci Lett 2019; 699:189-194. [PMID: 30753913 DOI: 10.1016/j.neulet.2019.01.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/27/2019] [Accepted: 01/30/2019] [Indexed: 11/27/2022]
Abstract
Tonic immobility (TI) is a temporary state of profound motor inhibition associated with great danger as the attack of a predator. Previous studies carried out in our laboratory evidenced high Fos-IR in the posteroventral region of the medial nucleus of the amygdala (MEA) after induction of the TI response. Here, we investigated the effects of GABAA and GABAB of the MEA on TI duration. Intra-MEA injections of the GABAA agonist muscimol and GABAB agonist baclofen reduced TI response, while intra-MEA injections of the GABAA antagonist bicuculline and GABAB antagonist phaclofen increased the TI response. Moreover, the effects observed with muscimol and baclofen administrations into MEA were blocked by pretreatment with bicuculline and phaclofen (at ineffective doses per se). Finally, the activation of GABAA and GABAB receptors in the MEA did not alter the spontaneous motor activity in the open field test. These data support the role of the GABAergic system of the MEA in the modulation of innate fear.
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Affiliation(s)
- Bruna B de Paula
- Department of Psychology, School of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-901, SP, Brazil
| | - Jeanne R de Melo
- Department of Psychology, School of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-901, SP, Brazil
| | - Christie R A Leite-Panissi
- Department of Psychology, School of Philosophy, Science and Literature of Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-901, SP, Brazil.
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29
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Assessment of fear and anxiety associated behaviors, physiology and neural circuits in rats with reduced serotonin transporter (SERT) levels. Transl Psychiatry 2019; 9:33. [PMID: 30670681 PMCID: PMC6343029 DOI: 10.1038/s41398-019-0368-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/15/2018] [Accepted: 10/05/2018] [Indexed: 01/11/2023] Open
Abstract
Genetic variation in serotonin transporter (SERT) that reduces transcriptional efficiency is associated with higher anxiety and fear traits and a greater incidence of post traumatic stress disorder (PTSD). Although previous studies have shown that rats with no expression of SERT (SERT-/-) have increased baseline anxiety behaviors, SERT+/- rats with low SERT expression (and more relevant to the clinical condition with low SERT expression) do not. Yet, no systematic studies of fear acquisition/extinction or their underlying neural mechanisms have been conducted in this preclinical genetic SERT+/- model. Here we sought to determine if SERT+/- or SERT-/-, compared to wildtype, rats would show exacerbated panic responses and/or persistent conditioned fear responses that may be associated with PTSD or phobia vulnerability. Results: Only SERT-/- rats showed increased baseline anxiety-like behaviors with heightened panic respiratory responses. However SERT+/- (also SERT-/-) rats showed enhanced acquisition of fear and delayed extinction of fear that was associated with changes in serotonergic-related genes (e.g., reduced 5-HT1A receptor) and disrupted inhibition within the basolateral amygdala (BLA). Furthermore, the disrupted fear responses in SERT+/- rats were normalized with 5HT1A antagonist infusions into the BLA. Enhanced acquisition and failure to extinguish fear memories displayed by both SERT-/- and SERT+/- rats are cardinal symptoms of disabling anxiety disorders such as phobias and PTSD. The data here support the hypothesis that reduced SERT function is a genetic risk that disrupts select gene expression and network properties in the amygdala that could result in vulnerability to these syndromes.
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30
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Radford KD, Park TY, Jaiswal S, Pan H, Knutsen A, Zhang M, Driscoll M, Osborne-Smith LA, Dardzinski BJ, Choi KH. Enhanced fear memories and brain glucose metabolism ( 18F-FDG-PET) following sub-anesthetic intravenous ketamine infusion in Sprague-Dawley rats. Transl Psychiatry 2018; 8:263. [PMID: 30504810 PMCID: PMC6269482 DOI: 10.1038/s41398-018-0310-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 09/25/2018] [Accepted: 11/08/2018] [Indexed: 12/18/2022] Open
Abstract
Ketamine is a multimodal dissociative anesthetic, which provides powerful analgesia for victims with traumatic injury. However, the impact of ketamine administration in the peri-trauma period on the development of post-traumatic stress disorder (PTSD) remains controversial. Moreover, there is a major gap between preclinical and clinical studies because they utilize different doses and routes of ketamine administration. Here, we investigated the effects of sub-anesthetic doses of intravenous (IV) ketamine infusion on fear memory and brain glucose metabolism (BGluM) in rats. Male Sprague-Dawley rats received an IV ketamine infusion (0, 2, 10, and 20 mg/kg, 2 h) or an intraperitoneal (IP) injection (0 and 10 mg/kg) following an auditory fear conditioning (3 pairings of tone and foot shock [0.6 mA, 1 s]) on day 0. Fear memory retrieval, fear extinction, and fear recall were tested on days 2, 3, and 4, respectively. The effects of IV ketamine infusion (0 and 10 mg/kg) on BGluM were measured using 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT). The IV ketamine infusion dose-dependently enhanced fear memory retrieval, delayed fear extinction, and increased fear recall in rats. The IV ketamine (10 mg/kg) increased BGluM in the hippocampus, amygdala, and hypothalamus, while decreasing it in the cerebellum. On the contrary, a single ketamine injection (10 mg/kg, IP) after fear conditioning facilitated fear memory extinction in rats. The current findings suggest that ketamine may produce differential effects on fear memory depending on the route and duration of ketamine administration.
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Affiliation(s)
- Kennett D. Radford
- 0000 0001 0421 5525grid.265436.0Daniel K. Inouye Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Thomas Y. Park
- 0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Shalini Jaiswal
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Hongna Pan
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Andrew Knutsen
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Michael Zhang
- 0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Mercedes Driscoll
- 0000 0001 0560 6544grid.414467.4National Capital Consortium Psychiatry Residency Program, Walter Reed National Military Medical Center, Bethesda, MD 20814 USA
| | - Lisa A. Osborne-Smith
- 0000 0000 9758 5690grid.5288.7Nurse Anesthesia Program, Oregon Health and Science University, Portland, OR 97239 USA
| | - Bernard J. Dardzinski
- 0000 0001 0421 5525grid.265436.0Center for Neuroscience and Regenerative Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Department of Radiology and Radiological Sciences, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
| | - Kwang H. Choi
- 0000 0001 0421 5525grid.265436.0Daniel K. Inouye Graduate School of Nursing, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA ,0000 0001 0421 5525grid.265436.0Center for the Study of Traumatic Stress, Uniformed Services University of the Health Sciences, Bethesda, MD 20814 USA
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Fox JH, Hassell JE, Siebler PH, Arnold MR, Lamb AK, Smith DG, Day HEW, Smith TM, Simmerman EM, Outzen AA, Holmes KS, Brazell CJ, Lowry CA. Preimmunization with a heat-killed preparation of Mycobacterium vaccae enhances fear extinction in the fear-potentiated startle paradigm. Brain Behav Immun 2017; 66:70-84. [PMID: 28888667 DOI: 10.1016/j.bbi.2017.08.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 08/02/2017] [Accepted: 08/15/2017] [Indexed: 12/31/2022] Open
Abstract
The hygiene hypothesis or "Old Friends" hypothesis proposes that inflammatory diseases are increasing in modern urban societies, due in part to reduced exposure to microorganisms that drive immunoregulatory circuits, and a failure to terminate inappropriate inflammatory responses. Inappropriate inflammation is also emerging as a risk factor for trauma-related, anxiety, and affective disorders, including posttraumatic stress disorder (PTSD), which is characterized as persistent re-experiencing of the trauma after a traumatic experience. Traumatic experiences can lead to long-lasting fear memories and exaggerated fear potentiation of the acoustic startle reflex. The acoustic startle reflex is an ethologically relevant reflex and can be potentiated in both humans and rats through Pavlovian conditioning. Mycobacterium vaccae NCTC 11659 is a soil-derived bacterium with immunoregulatory and anti-inflammatory properties that has been demonstrated to confer stress resilience in mice. Here we immunized adult male Sprague Dawley rats 3×, once per week, with a heat-killed preparation of M. vaccae NCTC 11659 (0.1mg, s.c., in 100µl borate-buffered saline) or vehicle, and, then, 3weeks following the final immunization, tested them in the fear-potentiated startle paradigm; controls were maintained under home cage control conditions throughout the experiment (n=11-12 per group). Rats were tested on days 1 and 2 for baseline acoustic startle, received fear conditioning on days 3 and 4, and underwent fear extinction training on days 5-10. Rats were euthanized on day 11 and brain tissue was sectioned for analysis of mRNA expression for genes important in control of brain serotonergic signaling, including tph2, htr1a, slc6a4, and slc22a3, throughout the brainstem dorsal and median raphe nuclei. Immunization with M. vaccae had no effect on baseline acoustic startle or fear expression on day 5. However, M. vaccae-immunized rats showed enhanced between-session and within-session extinction on day 6, relative to vehicle-immunized controls. Immunization with M. vaccae and fear-potentiated startle altered serotonergic gene expression in a gene- and subregion-specific manner. These data are consistent with the hypothesis that immunoregulatory strategies, such as preimmunization with M. vaccae, have potential for prevention of stress- and trauma-related psychiatric disorders.
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Affiliation(s)
- James H Fox
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - James E Hassell
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Philip H Siebler
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Mathew R Arnold
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Andrew K Lamb
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - David G Smith
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Heidi E W Day
- Department of Psychology and Neuroscience, University of Colorado Boulder, Boulder, CO 80309, USA.
| | - Tessa M Smith
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Emma M Simmerman
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Alexander A Outzen
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Kaley S Holmes
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Christopher J Brazell
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Christopher A Lowry
- Department of Integrative Physiology, University of Colorado Boulder, Boulder, CO 80309, USA; Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA; Department of Physical Medicine & Rehabilitation and Center for Neuroscience, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Rocky Mountain Mental Illness Research Education and Clinical Center, Denver, CO 80220, USA; Military and Veteran Microbiome Consortium for Research and Education (MVM-CoRE), Denver, CO 80220, USA.
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Genetically driven brain serotonin deficiency facilitates panic-like escape behavior in mice. Transl Psychiatry 2017; 7:e1246. [PMID: 28972592 PMCID: PMC5682603 DOI: 10.1038/tp.2017.209] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 07/14/2017] [Indexed: 01/06/2023] Open
Abstract
Multiple lines of evidence implicate brain serotonin (5-hydroxytryptamine; 5-HT) system dysfunction in the pathophysiology of stressor-related and anxiety disorders. Here we investigate the influence of constitutively deficient 5-HT synthesis on stressor-related anxiety-like behaviors using Tryptophan hydroxylase 2 (Tph2) mutant mice. Functional assessment of c-Fos after associated foot shock, electrophysiological recordings of GABAergic synaptic transmission, differential expression of the Slc6a4 gene in serotonergic neurons were combined with locomotor and anxiety-like measurements in different contextual settings. Our findings indicate that constitutive Tph2 inactivation and consequential lack of 5-HT synthesis in Tph2 null mutant mice (Tph2-/-) results in increased freezing to associated foot shock and a differential c-Fos activity pattern in the basolateral complex of the amygdala. This is accompanied by altered GABAergic transmission as observed by recordings of inhibitory postsynaptic currents on principal neurons in the basolateral nucleus, which may explain increased fear associated with hyperlocomotion and escape-like responses in aversive inescapable contexts. In contrast, lifelong 5-HT deficiency as observed in Tph2 heterozygous mice (Tph+/-) is able to be compensated through reduced GABAergic transmission in the basolateral nucleus of the amygdala based on Slc6a4 mRNA upregulation in subdivisions of dorsal raphe neurons. This results in increased activity of the basolateral nucleus of the amygdala due to associated foot shock. In conclusion, our results reflect characteristic syndromal dimensions of panic disorder and agoraphobia. Thus, constitutive lack of 5-HT synthesis influence the risk for anxiety- and stressor-related disorders including panic disorder and comorbid agoraphobia through the absence of GABAergic-dependent compensatory mechanisms in the basolateral nucleus of the amygdala.
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Adult Brain Serotonin Deficiency Causes Hyperactivity, Circadian Disruption, and Elimination of Siestas. J Neurosci 2017; 36:9828-42. [PMID: 27656022 DOI: 10.1523/jneurosci.1469-16.2016] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/03/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Serotonin (5-HT) is a crucial neuromodulator linked to many psychiatric disorders. However, after more than 60 years of study, its role in behavior remains poorly understood, in part because of a lack of methods to target 5-HT synthesis specifically in the adult brain. Here, we have developed a genetic approach that reproducibly achieves near-complete elimination of 5-HT synthesis from the adult ascending 5-HT system by stereotaxic injection of an adeno-associated virus expressing Cre recombinase (AAV-Cre) into the midbrain/pons of mice carrying a loxP-conditional tryptophan hydroxylase 2 (Tph2) allele. We investigated the behavioral effects of deficient brain 5-HT synthesis and discovered a unique composite phenotype. Surprisingly, adult 5-HT deficiency did not affect anxiety-like behavior, but resulted in a robust hyperactivity phenotype in novel and home cage environments. Moreover, loss of 5-HT led to an altered pattern of circadian behavior characterized by an advance in the onset and a delay in the offset of daily activity, thus revealing a requirement for adult 5-HT in the control of daily activity patterns. Notably, after normalizing for hyperactivity, we found that the normal prolonged break in nocturnal activity (siesta), a period of rapid eye movement (REM) and non-REM sleep, was absent in all animals in which 5-HT deficiency was verified. Our findings identify adult 5-HT as a requirement for siestas, implicate adult 5-HT in sleep-wake homeostasis, and highlight the importance of our adult-specific 5-HT-synthesis-targeting approach in understanding 5-HT's role in controlling behavior. SIGNIFICANCE STATEMENT Serotonin (5-HT) is a crucial neuromodulator, yet its role in behavior remains poorly understood, in part because of a lack of methods to target specifically adult brain 5-HT synthesis. We developed an approach that reproducibly achieves near-complete elimination of 5-HT synthesis from the adult ascending 5-HT system. Using this technique, we discovered that adult 5-HT deficiency led to a novel compound phenotype consisting of hyperactivity, disrupted circadian behavior patterns, and elimination of siestas, a period of increased sleep during the active phase. These findings highlight the importance of our approach in understanding 5-HT's role in behavior, especially in controlling activity levels, circadian behavior, and sleep-wake homeostasis, behaviors that are disrupted in many psychiatric disorders such as attention deficit hyperactivity disorder.
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Comparing the Expression of Genes Related to Serotonin (5-HT) in C57BL/6J Mice and Humans Based on Data Available at the Allen Mouse Brain Atlas and Allen Human Brain Atlas. Neurol Res Int 2017. [PMID: 28630769 PMCID: PMC5463198 DOI: 10.1155/2017/7138926] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Brain atlases are tools based on comprehensive studies used to locate biological characteristics (structures, connections, proteins, and gene expression) in different regions of the brain. These atlases have been disseminated to the point where tools have been created to store, manage, and share the information they contain. This study used the data published by the Allen Mouse Brain Atlas (2004) for mice (C57BL/6J) and Allen Human Brain Atlas (2010) for humans (6 donors) to compare the expression of serotonin-related genes. Genes of interest were searched for manually in each case (in situ hybridization for mice and microarrays for humans), normalized expression data (z-scores) were extracted, and the results were graphed. Despite the differences in methodology, quantification, and subjects used in the process, a high degree of similarity was found between expression data. Here we compare expression in a way that allows the use of translational research methods to infer and validate knowledge. This type of study allows part of the relationship between structures and functions to be identified, by examining expression patterns and comparing levels of expression in different states, anatomical correlations, and phenotypes between different species. The study concludes by discussing the importance of knowing, managing, and disseminating comprehensive, open-access studies in neuroscience.
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Synaptic Plasticity, Engrams, and Network Oscillations in Amygdala Circuits for Storage and Retrieval of Emotional Memories. Neuron 2017; 94:731-743. [DOI: 10.1016/j.neuron.2017.03.022] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 03/09/2017] [Accepted: 03/13/2017] [Indexed: 12/12/2022]
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Serotonin neurons in the dorsal raphe mediate the anticataplectic action of orexin neurons by reducing amygdala activity. Proc Natl Acad Sci U S A 2017; 114:E3526-E3535. [PMID: 28396432 DOI: 10.1073/pnas.1614552114] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Narcolepsy is a sleep disorder caused by the loss of orexin (hypocretin)-producing neurons and marked by excessive daytime sleepiness and a sudden weakening of muscle tone, or cataplexy, often triggered by strong emotions. In a mouse model for narcolepsy, we previously demonstrated that serotonin neurons of the dorsal raphe nucleus (DRN) mediate the suppression of cataplexy-like episodes (CLEs) by orexin neurons. Using an optogenetic tool, in this paper we show that the acute activation of DRN serotonin neuron terminals in the amygdala, but not in nuclei involved in regulating rapid eye-movement sleep and atonia, suppressed CLEs. Not only did stimulating serotonin nerve terminals reduce amygdala activity, but the chemogenetic inhibition of the amygdala using designer receptors exclusively activated by designer drugs also drastically decreased CLEs, whereas chemogenetic activation increased them. Moreover, the optogenetic inhibition of serotonin nerve terminals in the amygdala blocked the anticataplectic effects of orexin signaling in DRN serotonin neurons. Taken together, the results suggest that DRN serotonin neurons, as a downstream target of orexin neurons, inhibit cataplexy by reducing the activity of amygdala as a center for emotional processing.
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Zubedat S, Akirav I. The involvement of cannabinoids and mTOR in the reconsolidation of an emotional memory in the hippocampal-amygdala-insular circuit. Eur Neuropsychopharmacol 2017; 27:336-349. [PMID: 28131675 DOI: 10.1016/j.euroneuro.2017.01.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/13/2016] [Accepted: 01/05/2017] [Indexed: 12/20/2022]
Abstract
Memory reconsolidation is the process in which reactivated long-term memory becomes transiently sensitive to amnesic agents. We evaluated the ability of post reactivation administration of the mTOR inhibitor rapamycin, separately and in combination with the cannabinoid CB1/2 receptor agonist WIN55,212-2 (WIN), given systemically or specifically into the hippocampal CA1 area, basolateral amygdala (BLA) or insular cortex (IC), to reduce inhibitory avoidance fear in rats. Systemic administration of rapamycin after reactivation of fear memory impaired reconsolidation and facilitated extinction. A combined treatment with WIN and rapamycin resulted in similar effects. WIN injected systemically facilitated extinction, with no effect on reconsolidation. WIN alone and with rapamycin also decreased anxiety-like behavior. Further, when spontaneous recovery was tested, the WIN+rapamycin group did not demonstrate recovery of fear which can occur spontaneously after the passage of time. Rapamycin and WIN had differential effects on reconsolidation and extinction when microinjected into the CA1, BLA and IC. Furthermore, exposure to shock increased p70s6K activation in the BLA, indicating activation by mTOR. Treatment with rapamycin, WIN or WIN+rapamycin decreased activation and there was a strong positive correlation between fear retrieval and p70s6K activation in the BLA, suggesting that enhanced fear retrieval is associated with enhanced p70s6K activation. Taken together, the results suggest that rapamycin or a combined treatment that involves blocking mTOR and activating cannabinoids may be a promising pharmacological approach for the attenuation of reactivated emotional memories, and thus, it could represent a potential treatment strategy for disorders associated with traumatic memories.
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Affiliation(s)
- Salman Zubedat
- Department of Psychology, University of Haifa, Haifa 3498838, Israel
| | - Irit Akirav
- Department of Psychology, University of Haifa, Haifa 3498838, Israel.
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Control of Amygdala Circuits by 5-HT Neurons via 5-HT and Glutamate Cotransmission. J Neurosci 2017; 37:1785-1796. [PMID: 28087766 PMCID: PMC5320609 DOI: 10.1523/jneurosci.2238-16.2016] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 11/07/2016] [Accepted: 11/19/2016] [Indexed: 11/21/2022] Open
Abstract
The serotonin (5-HT) system and the amygdala are key regulators of emotional behavior. Several lines of evidence suggest that 5-HT transmission in the amygdala is implicated in the susceptibility and drug treatment of mood disorders. Therefore, elucidating the physiological mechanisms through which midbrain 5-HT neurons modulate amygdala circuits could be pivotal in understanding emotional regulation in health and disease. To shed light on these mechanisms, we performed patch-clamp recordings from basal amygdala (BA) neurons in brain slices from mice with channelrhodopsin genetically targeted to 5-HT neurons. Optical stimulation of 5-HT terminals at low frequencies (≤1 Hz) evoked a short-latency excitation of BA interneurons (INs) that was depressed at higher frequencies. Pharmacological analysis revealed that this effect was mediated by glutamate and not 5-HT because it was abolished by ionotropic glutamate receptor antagonists. Optical stimulation of 5-HT terminals at higher frequencies (10–20 Hz) evoked both slow excitation and slow inhibition of INs. These effects were mediated by 5-HT because they were blocked by antagonists of 5-HT2A and 5-HT1A receptors, respectively. These fast glutamate- and slow 5-HT-mediated responses often coexisted in the same neuron. Interestingly, fast-spiking and non-fast-spiking INs displayed differential modulation by glutamate and 5-HT. Furthermore, optical stimulation of 5-HT terminals did not evoke glutamate release onto BA principal neurons, but inhibited these cells directly via activation of 5-HT1A receptors and indirectly via enhanced GABA release. Collectively, these findings suggest that 5-HT neurons exert a frequency-dependent, cell-type-specific control over BA circuitry via 5-HT and glutamate co-release to inhibit the BA output. SIGNIFICANCE STATEMENT The modulation of the amygdala by serotonin (5-HT) is important for emotional regulation and is implicated in the pathogenesis and treatment of affective disorders. Therefore, it is essential to determine the physiological mechanisms through which 5-HT neurons in the dorsal raphe nuclei modulate amygdala circuits. Here, we combined optogenetic, electrophysiological, and pharmacological approaches to study the effects of activation of 5-HT axons in the basal nucleus of the amygdala (BA). We found that 5-HT neurons co-release 5-HT and glutamate onto BA neurons in a cell-type-specific and frequency-dependent manner. Therefore, we suggest that theories on the contribution of 5-HT neurons to amygdala function should be revised to incorporate the concept of 5-HT/glutamate cotransmission.
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Bocchio M, McHugh SB, Bannerman DM, Sharp T, Capogna M. Serotonin, Amygdala and Fear: Assembling the Puzzle. Front Neural Circuits 2016; 10:24. [PMID: 27092057 PMCID: PMC4820447 DOI: 10.3389/fncir.2016.00024] [Citation(s) in RCA: 108] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/21/2016] [Indexed: 11/13/2022] Open
Abstract
The fear circuitry orchestrates defense mechanisms in response to environmental threats. This circuitry is evolutionarily crucial for survival, but its dysregulation is thought to play a major role in the pathophysiology of psychiatric conditions in humans. The amygdala is a key player in the processing of fear. This brain area is prominently modulated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT). The 5-HT input to the amygdala has drawn particular interest because genetic and pharmacological alterations of the 5-HT transporter (5-HTT) affect amygdala activation in response to emotional stimuli. Nonetheless, the impact of 5-HT on fear processing remains poorly understood.The aim of this review is to elucidate the physiological role of 5-HT in fear learning via its action on the neuronal circuits of the amygdala. Since 5-HT release increases in the basolateral amygdala (BLA) during both fear memory acquisition and expression, we examine whether and how 5-HT neurons encode aversive stimuli and aversive cues. Next, we describe pharmacological and genetic alterations of 5-HT neurotransmission that, in both rodents and humans, lead to altered fear learning. To explore the mechanisms through which 5-HT could modulate conditioned fear, we focus on the rodent BLA. We propose that a circuit-based approach taking into account the localization of specific 5-HT receptors on neurochemically-defined neurons in the BLA may be essential to decipher the role of 5-HT in emotional behavior. In keeping with a 5-HT control of fear learning, we review electrophysiological data suggesting that 5-HT regulates synaptic plasticity, spike synchrony and theta oscillations in the BLA via actions on different subcellular compartments of principal neurons and distinct GABAergic interneuron populations. Finally, we discuss how recently developed optogenetic tools combined with electrophysiological recordings and behavior could progress the knowledge of the mechanisms underlying 5-HT modulation of fear learning via action on amygdala circuits. Such advancement could pave the way for a deeper understanding of 5-HT in emotional behavior in both health and disease.
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Affiliation(s)
- Marco Bocchio
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford Oxford, UK
| | - Stephen B McHugh
- Department of Experimental Psychology, University of Oxford Oxford, UK
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford Oxford, UK
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford Oxford, UK
| | - Marco Capogna
- MRC Brain Network Dynamics Unit, Department of Pharmacology, University of Oxford Oxford, UK
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