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Lemes JA, Silva MSCF, Gonçalves BSM, Céspedes IC, Viana MB. Deep Brain Stimulation of the dorsal raphe induces anxiolytic and panicolytic-like effects and alters serotonin immunoreactivity. Behav Brain Res 2023; 449:114462. [PMID: 37121276 DOI: 10.1016/j.bbr.2023.114462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 04/26/2023] [Accepted: 04/27/2023] [Indexed: 05/02/2023]
Abstract
Previously we showed that Deep Brain Stimulation (DBS) of the dorsal region (DRD) and of the lateral wings of the dorsal raphe (lwDR) respectively decreases anxiety and panic-like responses in the elevated T-maze (ETM). This study investigates neurobiological alterations which might respond for these behavioral effects. Male Wistar rats were submitted to high-frequency stimulation (100µA, 100Hz) of the DRD or of the lwDR for 1h, and subsequently tested in the avoidance or escape tasks of the ETM. Since serotonin (5-HT) reuptake inhibitors are first line pharmacological treatment for anxiety disorders, we also tested the effects of chronic fluoxetine administration (10mg/kg, IP, 21 days) on a separate group of rats. An open field was used for locomotor activity assessment. Additionally, we evaluated c-Fos immunoreactivity (Fos-ir) in serotonergic cells of the dorsal raphe (DR). Results showed that DBS of the DRD decreases avoidance reactions, an anxiolytic-like effect, without altering escape or locomotor activity. Both fluoxetine and DBS of the lwDR decreased escape responses in the ETM, a panicolytic-like effect, without altering avoidance measurements or locomotor activity. While DBS of the DRD decreased double immunostaining in the DRD, DBS of the lwDR increased Fos-ir and double immunostaining in the DRD and lwDR. Fluoxetine also increased double immunostaining in the lwDR and in the DRV but decreased it in the DRD. These results suggest that both the anxiolytic and panicolytic-like effects of DBS and fluoxetine are related to 5-HT modulation in different subnuclei of the DR.
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Affiliation(s)
- J A Lemes
- Departamento de Biociências, Federal University of São Paulo (UNIFESP), Santos, Brazil
| | - M S C F Silva
- Departamento de Biociências, Federal University of São Paulo (UNIFESP), Santos, Brazil
| | - B S M Gonçalves
- Departamento de Biociências, Federal University of São Paulo (UNIFESP), Santos, Brazil
| | - I C Céspedes
- Departamento de Morfologia e Genética, Escola Paulista de Medicina, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - M B Viana
- Departamento de Biociências, Federal University of São Paulo (UNIFESP), Santos, Brazil.
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2
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Vázquez-León P, Miranda-Páez A, Valencia-Flores K, Sánchez-Castillo H. Defensive and Emotional Behavior Modulation by Serotonin in the Periaqueductal Gray. Cell Mol Neurobiol 2022; 43:1453-1468. [PMID: 35902460 DOI: 10.1007/s10571-022-01262-z] [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: 04/18/2022] [Accepted: 07/13/2022] [Indexed: 11/26/2022]
Abstract
Serotonin 5-hydroxytryptamine (5-HT) is a key neurotransmitter for the modulation and/or regulation of numerous physiological processes and psychiatric disorders (e.g., behaviors related to anxiety, pain, aggressiveness, etc.). The periaqueductal gray matter (PAG) is considered an integrating center for active and passive defensive behaviors, and electrical stimulation of this area has been shown to evoke behavioral responses of panic, fight-flight, freezing, among others. The serotonergic activity in PAG is influenced by the activation of other brain areas such as the medial hypothalamus, paraventricular nucleus of the hypothalamus, amygdala, dorsal raphe nucleus, and ventrolateral orbital cortex. In addition, activation of other receptors within PAG (i.e., CB1, Oxytocin, µ-opioid receptor (MOR), and γ-aminobutyric acid (GABAA)) promotes serotonin release. Therefore, this review aims to document evidence suggesting that the PAG-evoked behavioral responses of anxiety, panic, fear, analgesia, and aggression are influenced by the activation of 5-HT1A and 5-HT2A/C receptors and their participation in the treatment of various mental disorders.
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Affiliation(s)
- Priscila Vázquez-León
- Neuropsychopharmacology Laboratory, Psychology School. 1er Piso Edif. B. Cub B001, National Autonomous University of Mexico, Avenida Universidad 3000, Colonia Copilco Universidad. Alcaldía de Coyoacan, Mexico City, Mexico
| | - Abraham Miranda-Páez
- Department of Physiology, National School of Biological Sciences, National Polytechnic Institute, Wilfrido Massieu esq. Manuel Stampa S/N Col. Nueva Industrial Vallejo, Gustavo A. Madero, Mexico City, CP:07738, Mexico
| | - Kenji Valencia-Flores
- Neuropsychopharmacology Laboratory, Psychology School. 1er Piso Edif. B. Cub B001, National Autonomous University of Mexico, Avenida Universidad 3000, Colonia Copilco Universidad. Alcaldía de Coyoacan, Mexico City, Mexico
| | - Hugo Sánchez-Castillo
- Neuropsychopharmacology Laboratory, Psychology School. 1er Piso Edif. B. Cub B001, National Autonomous University of Mexico, Avenida Universidad 3000, Colonia Copilco Universidad. Alcaldía de Coyoacan, Mexico City, Mexico.
- Research Unit of Psychobiology and Neurosciences (UIPyN), Psychology School, UNAM, CDMX Mexico, CP 04510, Mexico.
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3
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Maraschin JC, Frias AT, Hernandes PM, Batistela MF, Martinez LM, Joca SRL, Graeff FG, Audi EA, Spera de Andrade TGC, Zangrossi H. Antipanic-like effect of esketamine and buprenorphine in rats exposed to acute hypoxia. Behav Brain Res 2021; 418:113651. [PMID: 34732354 DOI: 10.1016/j.bbr.2021.113651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 10/19/2021] [Accepted: 10/29/2021] [Indexed: 12/26/2022]
Abstract
The antidepressant effect of ketamine has been widely acknowledged and the use of one of its enantiomers, S-ketamine (esketamine), has recently been approved for the clinical management of treatment-resistant depression. As with ketamine, the non-selective opioid receptor-interacting drug buprenorphine is reported to have antidepressant and anxiolytic properties in humans and rodents. Given the fact that antidepressant drugs are also first line treatment for panic disorder, it is surprising that the potential panicolytic effect of these compounds has been scarcely (ketamine), or not yet (buprenorphine) investigated. We here evaluated the effects of ketamine (the racemic mixture), esketamine, and buprenorphine in male Wistar rats submitted to a panicogenic challenge: acute exposure to hypoxia (7% O2). We observed that esketamine (20 mg/kg), but not ketamine, decreased the number of escape attempts made during hypoxia, and this effect could be observed even 7 days after the drug administration. A panicolytic-like effect was also observed with MK801, which like esketamine, antagonizes NMDA glutamate receptors. Buprenorphine (0.3 mg/kg) also impaired hypoxia-induced escape, an effect blocked by the non-selective opioid receptor antagonist naloxone, indicating an interaction with classical ligand sites, such as µ and kappa receptors, but not with nociception/orphanin FQ receptors. Altogether, the results suggest that esketamine and buprenorphine cause rapid-onset panicolytic-like effects, and may be alternatives for treating panic disorder, particularly in patients who are refractory to standard pharmacological treatment.
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Affiliation(s)
- Jhonatan Christian Maraschin
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Alana Tercino Frias
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Paloma Molina Hernandes
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Matheus Fitipaldi Batistela
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Lucas Motta Martinez
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Sâmia Regiane Lourenço Joca
- Department of Biomolecular Sciences, School of Pharmaceutical Sciences, University of São Paulo, Ribeirão Preto, SP, Brazil; Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus, Denmark
| | | | - Elisabeth Aparecida Audi
- Department of Pharmacology and Therapeutics, State University of Maringá (UEM), Maringá, PR, Brazil
| | | | - Hélio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil; Behavioural Neurosciences Institute (INeC), Ribeirão Preto, SP, Brazil.
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Vilela-Costa HH, Maraschin JC, Casarotto PC, Sant'Ana AB, de Bortoli VC, Vicente MA, Campos AC, Guimarães FS, Zangrossi H. Role of 5-HT 1A and 5-HT 2C receptors of the dorsal periaqueductal gray in the anxiety- and panic-modulating effects of antidepressants in rats. Behav Brain Res 2021; 404:113159. [PMID: 33571572 DOI: 10.1016/j.bbr.2021.113159] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/27/2021] [Accepted: 01/31/2021] [Indexed: 02/07/2023]
Abstract
Antidepressant drugs are first-line treatment for panic disorder. Facilitation of 5-HT1A receptor-mediated neurotransmission in the dorsal periaqueductal gray (dPAG), a key panic-associated area, has been implicated in the panicolytic effect of the selective serotonin reuptake inhibitor fluoxetine. However, it is still unknown whether this mechanism accounts for the antipanic effect of other classes of antidepressants drugs (ADs) and whether the 5-HT interaction with 5-HT2C receptors in this midbrain area (which increases anxiety) is implicated in the anxiogenic effect caused by short-term treatment with ADs. The results showed that previous injection of the 5-HT1A receptor antagonist WAY-100635 in the dPAG blocked the panicolytic-like effect caused by chronic systemic administration of the tricyclic AD imipramine in male Wistar rats tested in the elevated T-maze. Neither chronic treatment with imipramine nor fluoxetine changed the expression of 5-HT1A receptors in the dPAG. Treatment with these ADs also failed to significantly change ERK1/2 (extracellular-signal regulated kinase) phosphorylation level in this midbrain area. Blockade of 5-HT2C receptors in the dPAG with the 5-HT2C receptor antagonist SB-242084 did not change the anxiogenic effect caused by a single acute injection of fluoxetine or imipramine in the Vogel conflict test. These results reinforce the view that the facilitation of 5-HT1A receptor-mediated neurotransmission in the dPAG is a common mechanism involved in the panicolytic effect caused by chronic administration of ADs. On the other hand, the anxiogenic effect observed after short-term treatment with these drugs does not depend on 5-HT2C receptors located in the dPAG.
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MESH Headings
- Aminopyridines/pharmacology
- Animals
- Antidepressive Agents/pharmacology
- Anxiety/drug therapy
- Blotting, Western
- Elevated Plus Maze Test
- Fluoxetine/pharmacology
- Imipramine/pharmacology
- Indoles/pharmacology
- Male
- Open Field Test/drug effects
- Panic/drug effects
- Periaqueductal Gray/drug effects
- Periaqueductal Gray/metabolism
- Periaqueductal Gray/physiology
- Piperazines/pharmacology
- Pyridines/pharmacology
- Rats
- Rats, Wistar
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptor, Serotonin, 5-HT1A/physiology
- Receptor, Serotonin, 5-HT2C/drug effects
- Receptor, Serotonin, 5-HT2C/metabolism
- Receptor, Serotonin, 5-HT2C/physiology
- Serotonin 5-HT1 Receptor Antagonists/pharmacology
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Affiliation(s)
- Heloisa H Vilela-Costa
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Jhonatan Christian Maraschin
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | | | - Ana Beatriz Sant'Ana
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Valquiria C de Bortoli
- Department of Health Sciences, Federal University of Espírito Santo (UFES), São Mateus, ES, Brazil
| | - Maria Adrielle Vicente
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Alline Cristina Campos
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Francisco S Guimarães
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil
| | - Helio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (USP), Ribeirão Preto, SP, Brazil.
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Baptista-de-Souza D, Tavares LRR, Furuya-da-Cunha EM, Carneiro de Oliveira PE, Canto-de-Souza L, Nunes-de-Souza RL, Canto-de-Souza A. Chronic Fluoxetine Impairs the Effects of 5-HT 1A and 5-HT 2C Receptors Activation in the PAG and Amygdala on Antinociception Induced by Aversive Situation in Mice. Front Pharmacol 2020; 11:260. [PMID: 32218734 PMCID: PMC7078365 DOI: 10.3389/fphar.2020.00260] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 02/24/2020] [Indexed: 11/24/2022] Open
Abstract
Growing evidence suggests an important role of fluoxetine with serotonin 5-HT1A and 5-HT2C receptors in the modulation of emotion and nociception in brain areas such as the amygdala and periaqueductal gray (PAG). Acute fluoxetine impairs 5-HT2C (but not 5-HT1A) receptor activation in the amygdaloid complex. Given that fluoxetine produces its clinical therapeutic effects only when given chronically, this study investigated the effects of chronic treatment with fluoxetine on the effects produced by 5-HT1A or 5-HT2C receptors activation in the amygdala or PAG on fear-induced antinociception. We recorded the effects of chronic fluoxetine on serotonin and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) levels as well as serotonin turnover; 5-HT1A and 5-HT2C receptor protein levels in the amygdala and PAG. Also, we evaluated the effects of chronic fluoxetine combined with intra-amygdala or intra-PAG injection of MK-212 (a 5-HT2C agonist; 0.63 nmol) or 8-OH-DPAT (a 5-HT1A agonist; 10 nmol) on the antinociceptive response in mice confined in the open arm of the elevated plus-maze (EPM). Nociception was assessed with the writhing test induced by intraperitoneal injection of 0.6% acetic acid. Results showed that fluoxetine (20 mg/kg, s.c.) enhanced the open-arm induced antinociception (OAA) and reduced the number of writhes in mice confined in the enclosed arm, featuring an analgesic effect. In addition, fluoxetine increased the expression of 5-HT2C receptors and 5-HT levels whereas reduced its turnover in the amygdala. While fluoxetine did not change 5-HT and 5-HIAA levels, and its turnover in the PAG, it up-regulated 5HT1A and 5-HT2C receptors in this midbrain area. Chronic fluoxetine (5.0 mg/Kg, an intrinsically inactive dose on nociception) antagonized the enhancement of OAA produced by intra-amygdala or intra-PAG injection of MK-212. Fluoxetine also impaired the attenuation of OAA induced by intra-amygdala injection of 8-OH-DPAT and totally prevented OAA in mice that received intra-PAG 8-OH-DPAT. These results suggest that (i) 5-HT may facilitate nociception and intensify OAA, acting at amygdala 5-HT1A and 5-HT2C receptors, respectively, and (ii) fluoxetine modulates the OAA through activation of 5-HT2C receptors within the PAG. These findings indicate that chronic fluoxetine impairs the effects of 5-HT1A and 5-HT2C receptors activation in the amygdala and PAG on fear-induced antinociception in mice.
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Affiliation(s)
- Daniela Baptista-de-Souza
- Department of Psychology, Federal University of São Carlos-UFSCar, São Carlos, Brazil.,Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil.,Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil
| | - Lígia Renata Rodrigues Tavares
- Department of Psychology, Federal University of São Carlos-UFSCar, São Carlos, Brazil.,Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil
| | - Elke Mayumi Furuya-da-Cunha
- Department of Psychology, Federal University of São Carlos-UFSCar, São Carlos, Brazil.,Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil
| | - Paulo Eduardo Carneiro de Oliveira
- Department of Psychology, Federal University of São Carlos-UFSCar, São Carlos, Brazil.,Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil
| | - Lucas Canto-de-Souza
- Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil.,Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista - UNESP, Araraquara, Brazil
| | - Ricardo Luiz Nunes-de-Souza
- Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil.,Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil.,Laboratory of Pharmacology, School of Pharmaceutical Sciences, Univ. Estadual Paulista - UNESP, Araraquara, Brazil
| | - Azair Canto-de-Souza
- Department of Psychology, Federal University of São Carlos-UFSCar, São Carlos, Brazil.,Joint Graduate Program in Physiological Sciences, UFSCar/UNESP, São Carlos, Brazil.,Institute of Neuroscience and Behavior, Ribeirão Preto, Brazil.,Graduate Program in Psychology UFSCar, São Carlos, Brazil
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Maraschin JC, Sestile CC, Yabiku CT, Roncon CM, de Souza Fiaes GC, Graeff FG, Audi EA, Zangrossi H. Effects of the adjunctive treatment of antidepressants with opiorphin on a panic-like defensive response in rats. Behav Brain Res 2020; 378:112263. [PMID: 31568834 DOI: 10.1016/j.bbr.2019.112263] [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: 06/17/2019] [Revised: 09/25/2019] [Accepted: 09/26/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND Antidepressants are the first-choice for pharmacological treatment of panic disorder. However, they present disadvantages, such as delayed therapeutic effect, many side effects and a considerable rate of non-responders. These shortcomings prompt the development of new therapeutic strategies. Among these are the adjunctive use of enkephalinase inhibitors, such as opiorphin, which supposedly acts by increasing the availability of brain enkephalins and other endogenous opioids. AIMS We here evaluated whether opiorphin in the dorsal periaqueductal grey matter (dPAG), a key panic-related area, accelerates and/or facilitates the antipanic-like effect of fluoxetine or imipramine. We also verified whether the panicolytic effect of imipramine depends on activation of μ-opioid receptors (MORs). METHODS Male Wistar rats were submitted to the escape task of the elevated T-maze, an index of panic attack, after treatment with imipramine (3, 7 or 21 days) or fluoxetine (3, 7, 14 or 21 days), combined with an intra-dPAG injection of opiorphin. RESULTS Opiorphin facilitated and accelerated the panicolytic-like effect caused by imipramine, but not with fluoxetine. The antipanic-like effect caused by chronic imipramine did not depend on MOR activation in the dPAG. CONCLUSION Combined treatment of antidepressant drugs with opiorphin for hastening or potentiating the effects of the former compounds may not be generally effective, with the results varying depending on the type/class of these panicolytic drugs.
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Affiliation(s)
- Jhonatan Christian Maraschin
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil
| | - Caio César Sestile
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil
| | - Cláudia Tiemi Yabiku
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil
| | - Camila Marroni Roncon
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil
| | - Gislaine Cardoso de Souza Fiaes
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil
| | - Frederico Guilherme Graeff
- Behavioural Neurosciences Institute (INeC), Av. do Café, 2450, Monte Alegre, Ribeirão Preto, São Paulo, 14050-220, Brazil; Neurobiology of Emotions Research Centre (NAP-USP-NuPNE), School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirao Preto, São Paulo, 14049-900, Brazil
| | - Elisabeth Aparecida Audi
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná, 87020-900, Brazil; Behavioural Neurosciences Institute (INeC), Av. do Café, 2450, Monte Alegre, Ribeirão Preto, São Paulo, 14050-220, Brazil; Neurobiology of Emotions Research Centre (NAP-USP-NuPNE), School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirao Preto, São Paulo, 14049-900, Brazil
| | - Hélio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirão Preto, São Paulo, 14049-900, Brazil.
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Vilela-Costa HH, Spiacci A, Bissolli IG, Zangrossi H. A Shift in the Activation of Serotonergic and Non-serotonergic Neurons in the Dorsal Raphe Lateral Wings Subnucleus Underlies the Panicolytic-Like Effect of Fluoxetine in Rats. Mol Neurobiol 2019; 56:6487-6500. [DOI: 10.1007/s12035-019-1536-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/22/2019] [Indexed: 01/04/2023]
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Frias AT, Fernandes GG, Zangrossi H. GABA A/benzodiazepine receptors in the dorsal periaqueductal gray mediate the panicolytic but not the anxiolytic effect of alprazolam in rats. Behav Brain Res 2019; 364:99-105. [PMID: 30768992 DOI: 10.1016/j.bbr.2019.02.016] [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: 11/29/2018] [Revised: 02/01/2019] [Accepted: 02/11/2019] [Indexed: 01/04/2023]
Abstract
Although the etiology of panic disorder (PD) remains elusive, accumulating evidence suggests a key role for the dorsal periaqueductal gray matter (dPAG). There is also evidence that this midbrain area is critically involved in mediation of the panicolytic effect of antidepressants, which with high potency benzodiazepines (e.g. alprazolam and clonazepam) are first line treatment for PD. Whether the dPAG is also implicated in the antipanic effect of the latter drugs is, however, still unknown. We here investigated the consequences of blocking GABAA or benzodiazepine receptors within the dPAG, with bicuculline (5 pmol) and flumazenil (80 nmol), respectively, on the panicolytic and anxiolytic effects of alprazolam (4 mg/kg). Microinjection of these antagonists fully blocked the anti-escape effect, considered as a panicolytic-like action, caused by a single systemic injection of alprazolam in male Wistar rats submitted to the elevated T-maze. These antagonists, however, did not affect the anxiolytic effect of the benzodiazepine on inhibitory avoidance acquisition and punished responding, measured in the elevated T-maze and Vogel conflict tests, respectively. Altogether, our findings show the involvement of GABAA/benzodiazepine receptors of the dPAG in the panicolytic, but not the anxiolytic effect caused by alprazolam. They also implicate the dPAG as the fulcrum of the effects of different classes of clinically effective antipanic drugs.
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Affiliation(s)
- Alana Tercino Frias
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, Sao Paulo, Brazil
| | - Gabriel Gripp Fernandes
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, Sao Paulo, Brazil
| | - Hélio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900, Ribeirão Preto, Sao Paulo, Brazil.
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9
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Tavares LRR, Baptista-de-Souza D, Canto-de-Souza A. Activation of 5-HT2C (but not 5-HT1A) receptors in the amygdala enhances fear-induced antinociception: Blockade with local 5-HT2C antagonist or systemic fluoxetine. Neuropharmacology 2018; 135:376-385. [DOI: 10.1016/j.neuropharm.2018.03.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 03/05/2018] [Accepted: 03/06/2018] [Indexed: 12/28/2022]
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10
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A serotonergic deficit in the dorsal periaqueductal gray matter may underpin enhanced panic-like behavior in diabetic rats. Behav Pharmacol 2018; 28:558-564. [PMID: 28799955 DOI: 10.1097/fbp.0000000000000332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
It is known that diabetic (DBT) animals present dysregulation on the serotonergic system in several brain areas associated with anxiety-like responses. The aim of this study was to investigate the involvement of 5-HT1A receptors on dorsal periaqueductal gray (dPAG) in the behavioral response related to panic disorder in type-1 DBT animals. For this, the escape response by electric stimulation (ES) of dPAG in DBT and normoglycemic (NGL) animals was assessed. Both NGL and DBT animals were exposed to an open-field test (OFT) 28 days after DBT confirmation. The current threshold to induce escape behavior in DBT animals was reduced compared with NGL animals. No impairment in locomotor activity was observed when DBT animals were compared with NGL animals. An intra-dPAG injection of the 5-HT1A receptor agonist (±)-8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) increased the [INCREMENT] threshold in both DBT and NGL, suggesting a panicolytic-like effect. DBT animals presented a more pronounced panicolytic-like response compared with NGL as a higher [INCREMENT] threshold was observed after 8-OH-DPAT treatment, which could be a consequence of the increased expression of the 5-HT1A receptor in the dPAG from DBT animals. Our results are in line with the proposal that a deficiency in serotonergic modulation of the dPAG is involved in triggering the panic attack and the 5-HT1A receptors might be essential for the panicolytic-like response.
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Maraschin JC, Almeida CB, Rangel MP, Roncon CM, Sestile CC, Zangrossi H, Graeff FG, Audi EA. Participation of dorsal periaqueductal gray 5-HT1A receptors in the panicolytic-like effect of the κ-opioid receptor antagonist Nor-BNI. Behav Brain Res 2017; 327:75-82. [PMID: 28347824 DOI: 10.1016/j.bbr.2017.03.033] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/15/2017] [Accepted: 03/21/2017] [Indexed: 11/30/2022]
Abstract
Panic patients may have abnormalities in serotonergic and opioidergic neurotransmission. The dorsal periaqueductal gray (dPAG) plays an important role in organizing proximal defense, related to panic attacks. The 5-HT1A receptor (5-HT1A-R) is involved in regulating escape behavior that is organized in the dPAG. Activation of κ-opioid receptor (KOR) in this region causes anxiogenic effects. In this study, we investigated the involvement of KOR in regulating escape behavior, using systemic and intra-dPAG injection of the KOR antagonist Nor-BNI. As panic models, we used the elevated T-maze (ETM) and the dPAG electrical stimulation test (EST). We also evaluated whether activation of the 5-HT1A-R or the μ-opioid receptor (MOR) in the dPAG contributes to the Nor-BNI effects. The results showed that systemic administration of Nor-BNI, either subcutaneously (2.0 and 4.0mg/kg) or intraperitoneally (2.0mg/kg), impaired escape in the EST, indicating a panicolytic-like effect. Intra-dPAG injection of this antagonist (6.8nmol) caused the same effect in the EST and in the ETM. Association of ineffective doses of Nor-BNI and the 5-HT1A-R agonist 8-OH-DPAT caused panicolytic-like effect in these two tests. Previous administration of the 5-HT1A-R antagonist WAY-100635, but not of the MOR antagonist CTOP, blocked the panicolytic-like effect of Nor-BNI. These results indicate that KOR enhances proximal defense in the dPAG through 5-HT1A-R modulation, independently of MOR. Because former results indicate that the 5-HT1A-R is involved in the antipanic action of antidepressants, KOR antagonists may be useful as adjunctive or alternative drug treatment of panic disorder.
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Affiliation(s)
- Jhonatan Christian Maraschin
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil.
| | - Camila Biesdorf Almeida
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil
| | - Marcel Pereira Rangel
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil
| | - Camila Marroni Roncon
- Neurobiology of Emotions Research Centre (NAP-USP-NuPNE), School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirao Preto, São Paulo 14049-900, Brazil; Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Caio César Sestile
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil
| | - Hélio Zangrossi
- Neurobiology of Emotions Research Centre (NAP-USP-NuPNE), School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirao Preto, São Paulo 14049-900, Brazil; Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirão Preto, São Paulo 14049-900, Brazil
| | - Frederico Guilherme Graeff
- Behavioural Neurosciences Institute (INeC), Av. do Café, 2450, Monte Alegre, Ribeirão Preto, São Paulo 14050-220, Brazil; Neurobiology of Emotions Research Centre (NAP-USP-NuPNE), School of Medicine of Ribeirão Preto, University of São Paulo (FMRP-USP), Av. dos Bandeirantes, 3900, Ribeirao Preto, São Paulo 14049-900, Brazil
| | - Elisabeth Aparecida Audi
- Department of Pharmacology and Therapeutics, State University of Maringá, Av. Colombo, 5790, Maringá, Paraná 87020-900, Brazil; Behavioural Neurosciences Institute (INeC), Av. do Café, 2450, Monte Alegre, Ribeirão Preto, São Paulo 14050-220, Brazil.
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12
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Gambeta E, de Souza CP, de Morais H, Zanoveli JM. Reestablishment of the hyperglycemia to the normal levels seems not to be essential to the anxiolytic-like effect induced by insulin. Metab Brain Dis 2016; 31:563-71. [PMID: 26608284 DOI: 10.1007/s11011-015-9770-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/17/2015] [Indexed: 01/29/2023]
Abstract
Diabetes is a chronic metabolic disease accompanied by several comorbidities, including neuropsychiatric conditions. Since the hyperglycemia appears to be the primary factor involved in diabetic conditions, we examined the effect of insulin treatment in diabetic rats on behavioral responses related to anxiety and aversive memory extinction. For this, normoglycemic (NGL) or streptozotocin-diabetic (DBT) rats were submitted to the elevated T maze (ETM) and the contextual conditioned fear (CCF) tests. Therefore, animals were subjected to the prolonged treatment with insulin (6 IU/day, s.c.) to investigate the effect of the treatment on distinct behaviors. When anxiety-like responses such as the inhibitory avoidance (IA) on the ETM and the time of freezing in the first session of the CCF test were evaluated, our data showed a more pronounced anxiogenic-like behavior in DBT animals when compared to NGL ones. In addition, an increased freezing time was observed in DBT animals exposed to the CCF test (sessions 2 and 3) when compared to the NGL group, suggestive of an impairment in the extinction of aversive memory. Insulin treatment induced an anxiolytic-like effect when IA and freezing time (session 1) was evaluated, but did not alter the impaired extinction of aversive memory (sessions 2 and 3). To better understand the involvement of a rigorous control of glycaemia, we also investigated the effect of a lower dose of insulin (3 IU/day, s.c.), unable to reestablish the hyperglycemia to the normal levels, on the same behavioral parameters. Our data show that independent of the dose of insulin, the same effects were observed when animals were evaluated in the ETM and CCF tests. However, only the highest dose of insulin was able to reduce the hyperglycemia to the normal levels. To conclude, our data suggest that a severe glycemic control by insulin treatment seems to be important, but not essential in improving diabetes-induced anxiety.
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Affiliation(s)
- Eder Gambeta
- Department of Pharmacology, Biological Sciences Building, Federal University of Paraná, Avenida Coronel H dos Santos S/N, P.O. Box 19031, Curitiba, PR, 81540-990, Brazil
| | - Camila Pasquini de Souza
- Department of Pharmacology, Biological Sciences Building, Federal University of Paraná, Avenida Coronel H dos Santos S/N, P.O. Box 19031, Curitiba, PR, 81540-990, Brazil
| | - Helen de Morais
- Department of Pharmacology, Biological Sciences Building, Federal University of Paraná, Avenida Coronel H dos Santos S/N, P.O. Box 19031, Curitiba, PR, 81540-990, Brazil
| | - Janaina Menezes Zanoveli
- Department of Pharmacology, Biological Sciences Building, Federal University of Paraná, Avenida Coronel H dos Santos S/N, P.O. Box 19031, Curitiba, PR, 81540-990, Brazil.
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13
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Roncon CM, Almada RC, Maraschin JC, Audi EA, Zangrossi H, Graeff FG, Coimbra NC. Pharmacological evidence for the mediation of the panicolytic effect of fluoxetine by dorsal periaqueductal gray matter μ-opioid receptors. Neuropharmacology 2015; 99:620-6. [DOI: 10.1016/j.neuropharm.2015.08.037] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 08/20/2015] [Accepted: 08/21/2015] [Indexed: 10/23/2022]
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14
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Casarotto PC, Santos PCD, Lucas GA, Biojone C, Pobbe RLH, Vilela-Costa HH, Joca SRL, Guimarães FS, Zangrossi H. BDNF-TRKB signaling system of the dorsal periaqueductal gray matter is implicated in the panicolytic-like effect of antidepressant drugs. Eur Neuropsychopharmacol 2015; 25:913-22. [PMID: 25840741 DOI: 10.1016/j.euroneuro.2015.03.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 02/24/2015] [Accepted: 03/09/2015] [Indexed: 01/26/2023]
Abstract
A wealth of evidence implicates the BDNF-TRKB system in the therapeutic effects of antidepressant drugs (ADs) on mood disorders. However, little is known about the involvement of this system in the panicolytic property also exerted by these compounds. In the present study we evaluated the participation of the BDNF-TRKB system of the dorsal periaqueductal gray matter (DPAG), a core structure involved in the pathophysiology of panic disorder, in AD-induced panicolytic-like effects in rats. The results showed that short- (3 days) or long-term (21 days) systemic treatment with the tricyclic ADs imipramine, clomipramine or desipramine increased BDNF levels in the DPAG. Only longterm treatment with the selective serotonin reuptake inhibitor fluoxetine was able to increase BDNF levels in this structure. After 21-day treatment, fluoxetine and the three tricyclic ADs used also increased BDNF concentration in the hippocampus, a key area implicated in their mood-related actions. Neither in the DPAG nor hippocampus did long-term treatment with the standard anxiolytics diazepam, clonazepam or buspirone affect BDNF levels. Imipramine, both after short and long-term administration, and fluoxetine under the latter regimen, raised the levels of phosphorylated TRKB in the DPAG. Short-term treatment with imipramine or BDNF microinjection inhibited escape expression in rats exposed to the elevated T maze, considered as a panicolytic-like effect. This anti-escape effect was attenuated by the intra-DPAG administration of the TRK receptor antagonist k252a. Altogether, our data suggests that facilitation of the BDNF-TRKB system in the DPAG is implicated in the panicolytic effect of ADs.
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Affiliation(s)
- Plinio C Casarotto
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Paula C dos Santos
- Department of Ophtamology, Otorhinolaringology and Head and Neck Surgery, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Guilherme A Lucas
- Department of Physiology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Caroline Biojone
- Department of Physics and Chemistry, Ribeirao Preto School of Pharmaceutical Sciences, University of Sao Paulo, Brazil.
| | - Roger L H Pobbe
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Heloisa H Vilela-Costa
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Samia R L Joca
- Department of Physics and Chemistry, Ribeirao Preto School of Pharmaceutical Sciences, University of Sao Paulo, Brazil.
| | - Francisco S Guimarães
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
| | - Hélio Zangrossi
- Department of Pharmacology, Ribeirao Preto Medical School, University of Sao Paulo, Brazil.
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Andrews PW, Bharwani A, Lee KR, Fox M, Thomson JA. Is serotonin an upper or a downer? The evolution of the serotonergic system and its role in depression and the antidepressant response. Neurosci Biobehav Rev 2015; 51:164-88. [DOI: 10.1016/j.neubiorev.2015.01.018] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 01/08/2015] [Accepted: 01/15/2015] [Indexed: 12/17/2022]
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16
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Ding S, Li L, Zhou FM. Robust presynaptic serotonin 5-HT(1B) receptor inhibition of the striatonigral output and its sensitization by chronic fluoxetine treatment. J Neurophysiol 2015; 113:3397-409. [PMID: 25787955 DOI: 10.1152/jn.00831.2014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/12/2015] [Indexed: 11/22/2022] Open
Abstract
The striatonigral projection is a striatal output pathway critical to motor control, cognition, and emotion regulation. Its axon terminals in the substantia nigra pars reticulata (SNr) express a high level of serotonin (5-HT) type 1B receptors (5-HT(1B)Rs), whereas the SNr also receives an intense 5-HT innervation that expresses 5-HT transporters, providing an anatomic substrate for 5-HT and selective 5-HT reuptake inhibitor (SSRI)-based antidepressant treatment to regulate the striatonigral output. In this article we show that 5-HT, by activating presynaptic 5-HT(1B)Rs on the striatonigral axon terminals, potently inhibited the striatonigral GABA output, as reflected in the reduction of the striatonigral inhibitory postsynaptic currents in SNr GABA neurons. Functionally, 5-HT(1B)R agonism reduced the striatonigral GABA output-induced pause of the spontaneous high-frequency firing in SNr GABA neurons. Equally important, chronic SSRI treatment with fluoxetine enhanced this presynaptic 5-HT(1B)R-mediated pause reduction in SNr GABA neurons. Taken together, these results indicate that activation of the 5-HT(1B)Rs on the striatonigral axon terminals can limit the motor-promoting GABA output. Furthermore, in contrast to the desensitization of 5-HT1 autoreceptors, chronic SSRI-based antidepressant treatment sensitizes this presynaptic 5-HT(1B)R-mediated effect in the SNr, a novel cellular mechanism that alters the striatonigral information transfer, potentially contributing to the behavioral effects of chronic SSRI treatment.
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Affiliation(s)
- Shengyuan Ding
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, Tennessee
| | - Li Li
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, Tennessee
| | - Fu-Ming Zhou
- Department of Pharmacology, University of Tennessee College of Medicine, Memphis, Tennessee
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17
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Pereira-Figueiredo I, Carro J, Muñoz LJ, Sancho C, Castellano O, Gómez-Nieto R, López DE. Sex Differences in the Effects of Sertraline and Stressors in Rats Previously Exposed to Restraint Stress. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/jbise.2015.87038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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18
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Cassaday HJ, Thur KE. Intraperitoneal sertraline and fluvoxamine increase contextual fear conditioning but are without effect on overshadowing between cues. Pharmacol Biochem Behav 2014; 129:111-5. [PMID: 25532461 PMCID: PMC4304005 DOI: 10.1016/j.pbb.2014.12.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Revised: 12/04/2014] [Accepted: 12/16/2014] [Indexed: 12/29/2022]
Abstract
Treatment with selective serotonin reuptake inhibitors (SSRIs) can reduce contextual conditioning. Since contexts comprise a variety of potentially competing cues, impaired overshadowing may provide an account of such effects. The present study therefore compared the effects of two SSRIs on overshadowing and contextual conditioning, testing suppression of an ongoing behavioral response (licking) by cues previously paired with foot shock. Conditioning to a 5 s light stimulus was reduced when it was presented in compound with a 5 s noise, thus overshadowing was demonstrated. In two experiments, this overshadowing was unaffected by treatment with either sertraline or fluvoxamine. However, unconditioned suppression to the noise (tested in a control group previously conditioned to the light alone) was reduced after sertraline (10 mg/kg, i.p.). The successful demonstration of overshadowing required the use of a second conditioning session or an additional conditioning trial within the same conditioning session. Neither weak nor strong overshadowing (of the light by the tone) was affected by any drug treatment. Moreover, counter to prediction, conditioning to contextual cues was increased rather than impaired by treatment with sertraline (10 mg/kg, i.p.) and fluvoxamine (30 mg/kg, i.p.). Setraline (10 mg/kg) increased latency to drink in the conditioning context. Fluvoxamine (30 mg/kg) reduced licking in the conditioning context. Discrete cue conditioning to an overshadowed light cue was unaffected. Setraline (10 mg/kg) reduced unconditioned suppression to the overshadowing noise.
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Affiliation(s)
- H J Cassaday
- School of Psychology, University of Nottingham, Nottingham, NG7 2RD, UK.
| | - K E Thur
- School of Psychology, University of Nottingham, Nottingham, NG7 2RD, UK
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19
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Bagatin MC, Tozatti CSS, Abiko LA, Yamazaki DADS, Silva PRA, Perego LM, Audi EA, Seixas FAV, Basso EA, Gauze GDF. Molecular docking and panicolytic effect of 8-prenylnaringenin in the elevated T-maze. Chem Pharm Bull (Tokyo) 2014; 62:1231-7. [PMID: 25450631 DOI: 10.1248/cpb.c14-00569] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to investigate the effects of the chronic administration of a racemic mixture of 8-prenylnaringenin (8-PN) on rats submitted to the elevated T-maze (ETM) model of generalized anxiety and panic disorders. The selective serotonin (SERT) reuptake inhibitor fluoxetine was used as a positive control. Rat locomotion was assessed in a circular arena following each drug treatment. The administration of racemic 8-PN for 21 d in rats increased one-way escape latencies from the ETM open arm, indicating a panicolytic effect. To evaluate the interactions of 8-PN with monoamine transporters, a docking study was performed for both the R and S configurations of 8-PN towards SERT, norepinephrine (NET) and dopamine transporters (DAT). The application of the docking protocol showed that (R)-8-PN provides greater affinity to all transporters than does the S enantiomer. This result suggests that enantiomer (R)-8-PN is the active form in the in vivo test of the racemic mixture.
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Serotonin in anxiety and panic: Contributions of the elevated T-maze. Neurosci Biobehav Rev 2014; 46 Pt 3:397-406. [DOI: 10.1016/j.neubiorev.2014.03.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 02/05/2014] [Accepted: 03/03/2014] [Indexed: 11/21/2022]
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21
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Dorsomedial hypothalamus serotonin 1A receptors mediate a panic-related response in the elevated T-maze. Brain Res Bull 2014; 109:39-45. [DOI: 10.1016/j.brainresbull.2014.09.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/23/2014] [Accepted: 09/24/2014] [Indexed: 11/22/2022]
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22
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Paul ED, Johnson PL, Shekhar A, Lowry CA. The Deakin/Graeff hypothesis: focus on serotonergic inhibition of panic. Neurosci Biobehav Rev 2014; 46 Pt 3:379-96. [PMID: 24661986 PMCID: PMC4170046 DOI: 10.1016/j.neubiorev.2014.03.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Revised: 02/15/2014] [Accepted: 03/01/2014] [Indexed: 12/20/2022]
Abstract
The Deakin/Graeff hypothesis proposes that different subpopulations of serotonergic neurons through topographically organized projections to forebrain and brainstem structures modulate the response to acute and chronic stressors, and that dysfunction of these neurons increases vulnerability to affective and anxiety disorders, including panic disorder. We outline evidence supporting the existence of a serotonergic system originally discussed by Deakin/Graeff that is implicated in the inhibition of panic-like behavioral and physiological responses. Evidence supporting this panic inhibition system comes from the following observations: (1) serotonergic neurons located in the 'ventrolateral dorsal raphe nucleus' (DRVL) as well as the ventrolateral periaqueductal gray (VLPAG) inhibit dorsal periaqueductal gray-elicited panic-like responses; (2) chronic, but not acute, antidepressant treatment potentiates serotonin's panicolytic effect; (3) contextual fear activates a central nucleus of the amygdala-DRVL/VLPAG circuit implicated in mediating freezing and inhibiting panic-like escape behaviors; (4) DRVL/VLPAG serotonergic neurons are central chemoreceptors and modulate the behavioral and cardiorespiratory response to panicogenic agents such as sodium lactate and CO2. Implications of the panic inhibition system are discussed.
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Affiliation(s)
- Evan D Paul
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Philip L Johnson
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Anantha Shekhar
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
| | - Christopher A Lowry
- Department of Integrative Physiology and Center for Neuroscience, University of Colorado Boulder, Boulder, CO 80309-0354, USA.
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de Bortoli VC, Yamashita PSDM, Zangrossi H. 5-HT1A and 5-HT2A receptor control of a panic-like defensive response in the rat dorsomedial hypothalamic nucleus. J Psychopharmacol 2013; 27:1116-23. [PMID: 23787365 DOI: 10.1177/0269881113492900] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The dorsomedial nucleus of the hypothalamus (DMH) has long been implicated in the genesis/regulation of escape, a panic-related defensive behavior. In the dorsal periaqueductal gray matter (dPAG), another key panic-associated area, serotonin, through the activation of 5-HT1A and 5-HT2A receptors, exerts an inhibitory role on escape expression. This panicolytic-like effect is facilitated by chronic treatment with clinically effective antipanic drugs such as fluoxetine and imipramine. It is still unclear whether serotonin within the DMH plays a similar regulatory action. The results showed that intra-DMH injection of the 5-HT1A receptor agonist 8-OH-DPAT, the preferential 5-HT2A receptor agonist DOI, but not the 5-HT2C agonist MK-212, inhibited the escape reaction of male Wistar rats evoked by electrical stimulation of the DMH. Local microinjection of the 5-HT1A antagonist WAY-100635 or the preferential 5-HT2A antagonist ketanserin was ineffective. Whereas chronic (21 days) systemic treatment with imipramine potentiated the anti-escape effect of both 8-OH-DPAT and DOI, repeated administration of fluoxetine enhanced the effect of the latter agonist. The results indicate that 5-HT1A and 5-HT2A receptors within the DMH play a phasic inhibitory role upon escape expression, as previously reported in the dPAG. Facilitation of 5-HT-mediated neurotransmission in the DMH may be implicated in the mode of action of antipanic drugs.
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Vicente MA, Zangrossi H. Involvement of 5-HT2C and 5-HT1A receptors of the basolateral nucleus of the amygdala in the anxiolytic effect of chronic antidepressant treatment. Neuropharmacology 2013; 79:127-35. [PMID: 24275045 DOI: 10.1016/j.neuropharm.2013.11.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/30/2022]
Abstract
Facilitation of serotonin 2C- and 1A-receptor (5-HT2C-R and 5-HT1A-R) mediated neurotransmission in the basolateral nucleus of the amygdala (BLA) has been associated with anxiogenic and anxiolytic effects, respectively. It has been also shown that stimulation of BLA 5-HT2C-Rs underlies the anxiogenic effect caused by acute systemic administration of the antidepressants imipramine or fluoxetine. Here we investigated whether chronic treatment with these two antidepressants, which causes anxiolytic effects, decreases the responsiveness of these receptors in the BLA. We also investigated whether the blockage of 5-HT1A-Rs in the same amygdala nucleus alters the anxiolytic effect of chronic imipramine treatment. The results showed that in male Wistar rats intra-BLA injection of the 5-HT2C-R agonist MK-212 facilitated inhibitory avoidance acquisition in the elevated T-maze and decreased the percentage of time spent by the animals in the lit compartment of the light-dark transition test, indicating an anxiogenic effect. Chronic (21 days) systemic treatment with imipramine (5 or 15 mg/kg) or fluoxetine (10 mg/kg) abolished these effects of MK-212. Acute administration of imipramine (5 mg/kg) failed to interfere with MK-212 effects in both tests. Intra-BLA injection of the 5-HT1A antagonist WAY-100635 blocked the anxiolytic, but not the panicolytic, effect of imipramine in the tests used. Our findings indicate that both a reduction in 5-HT2C-R- and a facilitation of 5-HT1A-R-mediated neurotransmission in the BLA are involved in the anxiolytic effect of antidepressant drugs.
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Affiliation(s)
- Maria Adrielle Vicente
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
| | - Helio Zangrossi
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 14049-900 Ribeirão Preto, SP, Brazil.
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25
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Le Maître E, Dourmap N, Vilpoux C, Leborgne R, Janin F, Bonnet JJ, Costentin J, Leroux-Nicollet I. Acute and subchronic treatments with selective serotonin reuptake inhibitors increase Nociceptin/Orphanin FQ (NOP) receptor density in the rat dorsal raphe nucleus; interactions between nociceptin/NOP system and serotonin. Brain Res 2013; 1520:51-60. [PMID: 23669068 DOI: 10.1016/j.brainres.2013.05.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 05/02/2013] [Accepted: 05/03/2013] [Indexed: 12/14/2022]
Abstract
Nociceptin/Orphanin FQ is the endogenous ligand of NOP receptor, formerly referred to as the Opioid Receptor-Like 1 receptor. We have previously shown that NOP receptors were located on serotonergic neurons in the rat dorsal raphe nucleus, suggesting possible direct interactions between nociceptin and serotonin in this region, which is a target for antidepressant action. In the present study, we investigated further the link between Selective Serotonin Reuptake Inhibitor (SSRI) antidepressant treatments and the nociceptin/NOP receptor system. Intraperitoneal administration of the SSRI citalopram induced an increase in NOP-receptor density, measured by autoradiographic [(3)H] nociceptin binding, in the rat dorsal raphe nucleus, from the first to the 21st day of treatment. This effect was also observed with other SSRIs (sertraline, fluoxetine), but not with two tricyclic antidepressants (imipramine, clomipramine) and was abolished by pre-treatment with para-chlorophenylalanine, an inhibitor of serotonin synthesis. Using microdialysis experiments, we demonstrated that NOP-receptor activation by infusion of nociceptin 10(-6) M or 10(-5) M increased the level of extracellular serotonin in the dorsal raphe nucleus. This effect was abolished by co-infusion of the NOP-receptor antagonist UFP 101. These results confirm the existence of reciprocal interactions between serotonin and nociceptin/NOP transmissions in the dorsal raphe nucleus.
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Affiliation(s)
- Erwan Le Maître
- Unité de Neuropsychopharmacologie de la Dépression, EA 4359, IRIB, Faculté de Médecine-Pharmacie, 22 Bd. Gambetta, 76183 Rouen Cedex 1, France
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Rangel MP, de Mello JCP, Audi EA. Evaluation of neurotransmitters involved in the anxiolytic and panicolytic effect of the aqueous fraction of Paullinia cupana (guaraná) in elevated T maze. REVISTA BRASILEIRA DE FARMACOGNOSIA-BRAZILIAN JOURNAL OF PHARMACOGNOSY 2013. [DOI: 10.1590/s0102-695x2013005000024] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Campos AC, de Paula Soares V, Carvalho MC, Ferreira FR, Vicente MA, Brandão ML, Zuardi AW, Zangrossi H, Guimarães FS. Involvement of serotonin-mediated neurotransmission in the dorsal periaqueductal gray matter on cannabidiol chronic effects in panic-like responses in rats. Psychopharmacology (Berl) 2013; 226:13-24. [PMID: 23007604 DOI: 10.1007/s00213-012-2878-7] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 09/06/2012] [Indexed: 11/30/2022]
Abstract
RATIONALE Cannabidiol (CBD) is a non-psychotomimetic constituent of Cannabis sativa plant that promotes antianxiety and anti-panic effects in animal models after acute systemic or intra-dorsal periaqueductal gray (DPAG) administration. However, the effects of CBD repeated administration, and the possible mechanisms involved, in animal models of anxiety- and panic-related responses remain poorly understood. OBJECTIVE The present study evaluates the role of the serotonergic neurotransmission within the DPAG in the modulation of escape responses of rats chronically treated with CBD. METHODS Male Wistar rats received acute or repeated (5 mg/Kg/daily/21 days) administration of CBD and were submitted to the elevated T-maze (ETM). We also investigated if CBD effects on the ETM depend on facilitation of 5-HT1A-mediated neurotransmission in the DPAG. To this latter aim, we verified if these effects would be prevented by intra-DPAG injection of the 5-HT1A receptor antagonist WAY100635 (0.37 nmol/0.2 μL). Also, we verified, by in vivo microdialysis, if CBD chronic treatment increases serotonin (5-HT) release and, by quantitative polymerase chain reaction, if there are changes in 5HT-1A or 5HT-2C mRNA expression in DPAG. RESULTS The results showed that repeated but not acute peripheral administration of CBD decreases escape responses in the ETM, suggesting a panicolytic effect. This treatment did not change 5HT-1A or 5-HT-2C receptor mRNA expression nor modify serotonin extracellular concentrations in the DPAG. CBD effects were prevented by DPAG injection of the 5-HT1A receptor antagonist. CONCLUSIONS Together, these findings suggest that repeated treatment with CBD induces anti-panic effects by acting on 5-HT1A receptors in DPAG.
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Affiliation(s)
- Alline Cristina Campos
- Department of Pharmacology, School of Medicine of Ribeirão Preto, University of São Paulo, 3900 Bandeirantes av., Monte Alegre, Ribeirão Preto, São Paulo, Brazil.
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Albert PR. Transcriptional regulation of the 5-HT1A receptor: implications for mental illness. Philos Trans R Soc Lond B Biol Sci 2012; 367:2402-15. [PMID: 22826341 DOI: 10.1098/rstb.2011.0376] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The serotonin-1A (5-HT(1A)) receptor is an abundant post-synaptic 5-HT receptor (heteroreceptor) implicated in regulation of mood, emotion and stress responses and is the major somatodendritic autoreceptor that negatively regulates 5-HT neuronal activity. Based on animal models, an integrated model for opposing roles of pre- and post-synaptic 5-HT(1A) receptors in anxiety and depression phenotypes and response to antidepressants is proposed. Understanding differential transcriptional regulation of pre- versus post-synaptic 5-HT(1A) receptors could provide better tools for their selective regulation. This review examines the transcription factors that regulate brain region-specific basal and stress-induced expression of the 5-HT(1A) receptor gene (Htr1a). A functional polymorphism, rs6295 in the Htr1a promoter region, blocks the function of specific repressors Hes1, Hes5 and Deaf1, resulting in increased 5-HT(1A) autoreceptor expression in animal models and humans. Its association with altered 5-HT(1A) expression, depression, anxiety and antidepressant response are related to genotype frequency in different populations, sample homogeneity, disease outcome measures and severity. Preliminary evidence from gene × environment studies suggests the potential for synergistic interaction of stress-mediated repression of 5-HT(1A) heteroreceptors, and rs6295-induced upregulation of 5-HT(1A) autoreceptors. Targeted therapeutics to inhibit 5-HT(1A) autoreceptor expression and induce 5-HT(1A) heteroreceptor expression may ameliorate treatment of anxiety and major depression.
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Affiliation(s)
- Paul R Albert
- Ottawa Hospital Research Institute (Neuroscience), University of Ottawa, , 451 Smyth Road, Ottawa, ON, Canada , K1H 8M5.
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Roncon CM, Biesdorf C, Santana RG, Zangrossi H, Graeff FG, Audi EA. The panicolytic-like effect of fluoxetine in the elevated T-maze is mediated by serotonin-induced activation of endogenous opioids in the dorsal periaqueductal grey. J Psychopharmacol 2012; 26:525-31. [PMID: 22279131 DOI: 10.1177/0269881111434619] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Serotonin (5-HT), opioids and the dorsal periaqueductal grey (DPAG) have been implicated in the pathophysiology of panic disorder. In order to study 5-HT-opioid interaction, the opioid antagonist naloxone was injected either systemically (1 mg/kg, i.p.) or intra-DPAG (0.2 μg/0.5 μL) to assess its interference with the effect of chronic fluoxetine (10 mg/kg, i.p., daily for 21 days) or of intra-DPAG 5-HT (8 μg/0.5 μL). Drug effects were measured in the one-escape task of the rat elevated T-maze, an animal model of panic. Pretreatment with systemic naloxone antagonized the lengthening of escape latency caused by chronic fluoxetine, considered a panicolytic-like effect that parallels the drug's therapeutic response in the clinics. Pretreatment with naloxone injected intra-DPAG antagonized both the panicolytic effect of chronic fluoxetine as well as that of 5-HT injected intra-DPAG. Neither the performance of the inhibitory avoidance task in the elevated T-maze, a model of generalized anxiety nor locomotion measured in a circular arena was affected by the above drug treatments. These results indicate that the panicolytic effect of fluoxetine is mediated by endogenous opioids that are activated by 5-HT in the DPAG. They also allow reconciliation between the serotonergic and opioidergic hypotheses of panic disorder pathophysiology.
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Affiliation(s)
- Camila M Roncon
- Department of Pharmacology and Therapeutic, State University of Maringá, Maringá, Brazil
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Sela VR, Biesdorf C, Ramos DH, Zangrossi H, Graeff FG, Audi EA. Serotonin-1A receptors in the dorsal periaqueductal gray matter mediate the panicolytic-like effect of pindolol and paroxetine combination in the elevated T-maze. Neurosci Lett 2011; 495:63-6. [PMID: 21421022 DOI: 10.1016/j.neulet.2011.03.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 03/09/2011] [Accepted: 03/13/2011] [Indexed: 11/26/2022]
Abstract
The β-adrenergic blocker and 5-HT(1A) receptor antagonist pindolol has been combined with selective serotonin reuptake inhibitors (SSRIs) in patients with depressive and anxiety disorders to shorten the onset of the clinical action and/or increase the proportion of responders. The results of a previous study have shown that pindolol potentiates the panicolytic effect of paroxetine in rats submitted to the elevated T-maze (ETM). Since reported evidence has implicated the 5-HT(1A) receptors of the dorsal periaqueductal gray matter (DPAG) in the panicolytic effect of antidepressants, rats treated with pindolol (5.0mg/kg, i.p.) and paroxetine (1.5mg/kg, i.p.) received a previous intra-DPAG injection of the selective 5-HT(1A) antagonist, WAY-100635 (0.4 μg) and were submitted to the ETM. Pretreatment with WAY-100635 reversed the increase in escape latency, a panicolytic effect, determined by the pindolol-paroxetine combination. These results implicate the 5-HT(1A) receptors of the DPAG in the panicolytic effect of the pindolol-paroxetine combination administered systemically. They also give further preclinical support for the use of this drug combination in the treatment of panic disorder.
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Affiliation(s)
- Vânia Ramos Sela
- Department of Pharmacology and Therapeutic, State University of Maringá, Av. Colombo, 5790 - Jardim Universitário, CEP: 87020900 Maringá, PR, Brazil
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Efficacy of chronic antidepressant treatments in a new model of extreme anxiety in rats. DEPRESSION RESEARCH AND TREATMENT 2011; 2011:531435. [PMID: 21808731 PMCID: PMC3144710 DOI: 10.1155/2011/531435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Revised: 05/31/2011] [Accepted: 06/03/2011] [Indexed: 11/23/2022]
Abstract
Animal models of anxious disorders found in humans, such as panic disorder and posttraumatic stress disorder, usually include spontaneous and conditioned fear that triggers escape and avoidance behaviors. The development of a panic disorder model with a learned component should increase knowledge of mechanisms involved in anxiety disorders. In our ethological model of extreme anxiety in the rat, forced apnea was combined with cold water vaporization in an inescapable situation. Based on the reactions of vehicle controls, behaviors involved in paroxysmic fear were passive (freezing) and active (jumping) reactions. Our results show that subchronic fluoxetine (5 mg/kg, IP, 21 days) and imipramine (10 mg/kg, IP, 14 days) administration alleviated freezing and jumping behaviors, whereas acute fluoxetine (1 mg/kg, IP) provoked opposite effects. Acute low dose of diazepam (1 mg/kg, IP) was not effective, whereas the higher dose of 3 mg/kg, IP, and clonazepam (1 mg/kg, IP) only had an effect on jumping. Paroxysmic fear generated in this experimental condition may therefore mimic the symptomatology observed in patients with anxiety disorders.
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Miguel TLB, Pobbe RLH, Spiacci A, Zangrossi H. Dorsal raphe nucleus regulation of a panic-like defensive behavior evoked by chemical stimulation of the rat dorsal periaqueductal gray matter. Behav Brain Res 2010; 213:195-200. [DOI: 10.1016/j.bbr.2010.04.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/26/2010] [Accepted: 04/29/2010] [Indexed: 11/24/2022]
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Facilitation of 5-HT1A-mediated neurotransmission in dorsal periaqueductal grey matter accounts for the panicolytic-like effect of chronic fluoxetine. Int J Neuropsychopharmacol 2010; 13:1079-88. [PMID: 19941697 DOI: 10.1017/s146114570999099x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chronic administration of antidepressants such as fluoxetine and imipramine increases the responsiveness of 5-HT(1A) receptors in dorsal periaqueductal grey matter (DPAG), a midbrain area consistently implicated in the pathogenesis of panic disorder. This effect has been related to the clinically relevant anti-panic action of these drugs. In this study we determined whether long-term administration of fluoxetine also affects 5-HT efflux in DPAG. As a comparison, the effect of chronic treatment with the anxiolytic 5-HT(1A) receptor agonist buspirone on DPAG 5-HT levels was assessed. We also investigated whether the inhibitory effect of chronic fluoxetine on escape behaviour in the rat elevated T-maze, considered as a panicolytic-like effect, is counteracted by intra-DPAG injection of the 5-HT(1A) receptor antagonist WAY 100635. Male Wistar rats were treated (1 or 21 d, i.p.) with fluoxetine, buspirone or vehicle, once daily. After treatment, 5-HT in DPAG was measured by in-vivo microdialysis coupled to HPLC. In another study, rats treated (21 d, i.p.) with either fluoxetine or vehicle also received intra-DPAG injection of WAY 100635 or saline 10 min before being tested in the elevated T-maze. Chronic, but not acute, administration of fluoxetine significantly raised extracellular levels of 5-HT in DPAG. Long-term treatment with buspirone was ineffective. In the elevated T-maze, intra-DPAG injection of WAY 100635 fully blocked the anti-escape effect of chronic administration of fluoxetine. Therefore, chronic fluoxetine facilitates 5-HT(1A)-mediated neurotransmission within DPAG and this effect accounts for the panicolytic-like effect of this antidepressant in the elevated T-maze.
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Panicolytic-like effect of BDNF in the rat dorsal periaqueductal grey matter: the role of 5-HT and GABA. Int J Neuropsychopharmacol 2010; 13:573-82. [PMID: 20047714 DOI: 10.1017/s146114570999112x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A wealth of evidence suggests a role for brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin-related kinase B (TrkB) in the aetiology of depression and in the mode of action of antidepressant drugs. Less clear is the involvement of this neurotrophin in other stress-related pathologies such as anxiety disorders. The dorsal periaqueductal grey matter (DPAG), a midbrain area rich in BDNF and TrkB receptor mRNAs and proteins, has been considered a key structure in the pathophysiology of panic disorder. In this study we investigated the effect of intra-DPAG injection of BDNF in a proposed animal model of panic: the escape response evoked by the electrical stimulation of the same midbrain area. To this end, the intensity of electrical current that needed to be applied to DPAG to evoke escape behaviour was measured before and after microinjection of BDNF. We also assessed whether 5-HT- or GABA-related mechanisms may account for the putative behavioural/autonomic effects of the neurotrophin. BDNF (0.05, 0.1, 0.2 ng) dose-dependently inhibited escape performance, suggesting a panicolytic-like effect. Local microinjection of K252a, an antagonist of TrkB receptors, or bicuculline, a GABAA receptor antagonist, blocked this effect. Intra-DPAG administration of WAY-100635 or ketanserin, respectively 5-HT1A and 5-HT2A/2C receptor antagonists, did not alter BDNF's effects on escape. Bicuculline also blocked the inhibitory effect of BDNF on mean arterial pressure increase caused by electrical stimulation of DPAG. Therefore, in the DPAG, BDNF-TrkB signalling interacts with the GABAergic system to cause a panicolytic-like effect.
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Muscle sympathetic nervous activity in depressed patients before and after treatment with sertraline. J Hypertens 2010; 27:2429-36. [PMID: 19684519 DOI: 10.1097/hjh.0b013e3283310ece] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND Sympathetic hyperactivity is one of the mechanisms involved in the increased cardiovascular risk associated with depression, and there is evidence that antidepressants decrease sympathetic activity. OBJECTIVES We tested the following two hypotheses: patients with major depressive disorder with high scores of depressive symptoms (HMDD) have augmented muscle sympathetic nervous system activity (MSNA) at rest and during mental stress compared with patients with major depressive disorder with low scores of depressive symptoms (LMDD) and controls; sertraline decreases MSNA in depressed patients. METHODS Ten HMDD, nine LMDD and 11 body weight-matched controls were studied. MSNA was directly measured from the peroneal nerve using microneurography for 3 min at rest and 4 min during the Stroop color word test. For the LMDD and HMDD groups, the tests were repeated after treatment with sertraline (103.3 +/- 40 mg). RESULTS Resting MSNA was significantly higher in the HMDD [29.1 bursts/min (SE 2.9)] compared with LMDD [19.9 (1.6)] and controls [22.2 (2.0)] groups (P = 0.026 and 0.046, respectively). There was a significant positive correlation between resting MSNA and severity of depression. MSNA increased significantly and similarly during stress in all the studied groups. Sertraline significantly decreased resting MSNA in the LMDD group and MSNA during mental stress in LMDD and HMDD groups. Sertraline significantly decreased resting heart rate and heart rate response to mental stress in the HMDD group. CONCLUSION Moderate-to-severe depression is associated with increased MSNA. Sertraline treatment reduces MSNA at rest and during mental challenge in depressed patients, which may have prognostic implications in this group.
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Drago A, Serretti A. Focus on HTR2C: A possible suggestion for genetic studies of complex disorders. Am J Med Genet B Neuropsychiatr Genet 2009; 150B:601-37. [PMID: 18802918 DOI: 10.1002/ajmg.b.30864] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
HTR2C is one of the most relevant and investigated serotonin receptors. Its role in important brain structures such as the midbrain, the lateral septal complex, the hypothalamus, the olfactory bulb, the pons, the choroid plexus, the nucleus pallidus, the striatum and the amygdala, the nucleus accumbens and the anterior cingulated gyrus candidate it as a promising target for genetic association studies. The biological relevance of these brain structures is reviewed by way of the focus on HTR2C activity, with a special attention paid to psychiatric disorders. Evidence from the genetic association studies that dealt with HTR2C is reviewed and discussed alongside the findings derived from the neuronatmic investigations. The reasons for the discrepancies between these two sets of reports are discussed. As a result, HTR2C is shown to play a pivotal role in many different psychiatric behaviors or psychiatric related disrupted molecular balances, nevertheless, genetic association studies brought inconsistent results so far. The most replicated association involve the feeding behavior and antipsychotic induced side effects, both weight gain and motor related: Cys23Ser (rs6318) and -759C/T (rs3813929) report the most consistent results. The lack of association found in other independent studies dampens the clinical impact of these reports. Here, we report a possible explanation for discrepant findings that is poorly or not at all usually considered, that is that HTR2C may exert different or even opposite activities in the brain depending on the structure analyzed and that mRNA editing activity may compensate possible genetically controlled functional effects. The incomplete coverage of the HTR2C variants is proposed as the best cost-benefit ratio bias to fix. The evidence of brain area specific HTR2C mRNA editing opens a debate about how the brain can differently modulate stress events, and process antidepressant treatments, in different brain areas. The mRNA editing activity on HTR2C may play a major role for the negative association results.
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Affiliation(s)
- Antonio Drago
- Institute of Psychiatry, University of Bologna, Italy
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Flesinoxan challenge suggests that chronic treatment with paroxetine in rats does not desensitize receptors controlling 5-HT synthesis. Neurochem Int 2008; 53:236-43. [DOI: 10.1016/j.neuint.2008.04.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2008] [Revised: 04/01/2008] [Accepted: 04/16/2008] [Indexed: 11/17/2022]
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Graeff FG, Del-Ben CM. Neurobiology of panic disorder: From animal models to brain neuroimaging. Neurosci Biobehav Rev 2008; 32:1326-35. [DOI: 10.1016/j.neubiorev.2008.05.017] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2007] [Revised: 05/02/2008] [Accepted: 05/02/2008] [Indexed: 10/22/2022]
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de Bortoli VC, Nogueira RL, Zangrossi H. Alprazolam potentiates the antiaversive effect induced by the activation of 5-HT(1A) and 5-HT (2A) receptors in the rat dorsal periaqueductal gray. Psychopharmacology (Berl) 2008; 198:341-9. [PMID: 18446327 DOI: 10.1007/s00213-008-1134-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2007] [Accepted: 03/01/2008] [Indexed: 01/22/2023]
Abstract
RATIONALE Serotonin in the dorsal periaqueductal gray (DPAG) through the activation of 5-HT(1A) and 5-HT(2A) receptors inhibits escape, a defensive behavior associated with panic attacks. Long-term treatment with antipanic drugs that nonselectively or selectively blocks the reuptake of serotonin (e.g., imipramine and fluoxetine, respectively) enhances the inhibitory effect on escape caused by intra-DPAG injection of 5-HT(1A) and 5-HT(2A) receptor agonists. It has been proposed that these compounds exert their effect on panic by facilitating 5-HT-mediated neurotransmission in the DPAG. OBJECTIVES The objective of this study was to investigate whether facilitation of 5-HT neurotransmission in the DPAG is also observed after treatment with alprazolam, a pharmacologically distinct antipanic drug that acts primarily as a high potency benzodiazepine receptor agonist. MATERIALS AND METHODS Male Wistar rats, subchronically (3-6 days) or chronically (14-17 days) treated with alprazolam (2 and 4 mg/kg, i.p.) were intra-DPAG injected with (+/-)-8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT), (+/-)-1-(2,5-dimethoxy-4-iodophenyl) piperazine dihydrochloride (DOI), and midazolam, respectively, 5-HT(1A), 5-HT(2A/2C), and benzodiazepine receptor agonists. The intensity of electrical current that needed to be applied to the DPAG to evoke escape behavior was measured before and after the microinjection of these agonists. RESULTS Intra-DPAG injection of the 5-HT agonists and midazolam increased the escape threshold in all groups of animals tested, indicating a panicolytic-like effect. The inhibitory effect of 8-OH-DPAT and DOI, but not midazolam, was significantly higher in animals receiving long-, but not short-term treatment with alprazolam. CONCLUSIONS Alprazolam as antidepressants compounds facilitates 5-HT(1A)- and 5-HT(2A)-receptor-mediated neurotransmission in the DPAG, implicating this effect in the mode of action of different classes of antipanic drugs.
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Affiliation(s)
- Valquíria Camin de Bortoli
- Department of Pharmacology, School of Medicine, University of São Paulo, 14049-900 Ribeirão Preto, São Paulo, Brazil
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