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Oliveira RN, Carvalhinho-Lopes PS, Carvalho CPF, Hirata RYS, Vaz SH, Sebastião AM, Armada-Moreira A, Rosário BA, Lemes JA, Soares-Silva B, de Andrade JS, Santos JR, Ribeiro AM, Viana MB. Neuroprotective effects of platinum nanoparticle-based microreactors in bicuculline-induced seizures. Behav Brain Res 2024; 465:114956. [PMID: 38479475 DOI: 10.1016/j.bbr.2024.114956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 04/14/2024]
Abstract
Epilepsy designates a group of chronic brain disorders, characterized by the recurrence of hypersynchronous, repetitive activity, of neuronal clusters. Epileptic seizures are the hallmark of epilepsy. The primary goal of epilepsy treatment is to eliminate seizures with minimal side effects. Nevertheless, approximately 30% of patients do not respond to the available drugs. An imbalance between excitatory/inhibitory neurotransmission, that leads to excitotoxicity, seizures, and cell death, has been proposed as an important mechanism regarding epileptogenesis. Recently, it has been shown that microreactors composed of platinum nanoparticles (Pt-NP) and glutamate dehydrogenase possess in vitro and in vivo activity against excitotoxicity. This study investigates the in vivo effects of these microreactors in an animal model of epilepsy induced by the administration of the GABAergic antagonist bicuculline. Male Wistar rats were administered intracerebroventricularly (i.c.v.) with the microreactors or saline and, five days later, injected with bicuculline or saline. Seizure severity was evaluated in an open field. Thirty min after behavioral measurements, animals were euthanized, and their brains processed for neurodegeneration evaluation and for neurogenesis. Treatment with the microreactors significantly increased the time taken for the onset of seizures and for the first tonic-clonic seizure, when compared to the bicuculline group that did not receive the microreactor. The administration of the microreactors also increased the time spent in total exploration and grooming. Treatment with the microreactors decreased bicuculline-induced neurodegeneration and increased neurogenesis in the dorsal and ventral hippocampus. These observations suggest that treatment with Pt-NP-based microreactors attenuates the behavioral and neurobiological consequences of epileptiform seizure activity.
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Affiliation(s)
- Roberto N Oliveira
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Patrícia S Carvalhinho-Lopes
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Carolina P F Carvalho
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Rafael Y S Hirata
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Sandra H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz MB, Lisboa 1649-028, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Professor Egas Moniz, Lisboa 1649-028, Portugal
| | - Ana Maria Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz MB, Lisboa 1649-028, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Av. Professor Egas Moniz, Lisboa 1649-028, Portugal
| | - Adam Armada-Moreira
- Neuronal Dynamics Laboratory, Scuola Internazionale Superiore di Studi Avanzati, via Bonomea, Trieste 265 - 34136, Italy
| | - Bárbara A Rosário
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Jéssica A Lemes
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Beatriz Soares-Silva
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - José S de Andrade
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - José Ronaldo Santos
- Departamento de Biociências, Universidade Federal de Sergipe, Rua Cláudio Batista, s/n, Cidade Nova Aracaju, Aracaju, Sergipe 49060-108, Brazil
| | - Alessandra M Ribeiro
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil
| | - Milena B Viana
- Departamento de Biociências, Universidade Federal de São Paulo (UNIFESP), Rua Silva Jardim, 136, Santos, São Paulo 11015-020, Brazil.
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Baghani M, Fathalizade F, Khakpai F, Fazli-Tabaei S, Zarrindast MR. Additive effect of histamine and muscimol upon induction of antinociceptive and antidepressant effects in mice. Behav Pharmacol 2024; 35:55-65. [PMID: 37401392 DOI: 10.1097/fbp.0000000000000729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
We investigated the effects of histamine and GABA A receptor agents on pain and depression-like behaviors and their interaction using a tail-flick test and the forced swimming test (FST) in male mice. Our data revealed that intraperitoneal administration of muscimol (0.12 and 0.25 mg/kg) increased the percentage of maximum possible effect (%MPE) and area under the curve (AUC) of %MPE, indicating an antinociceptive response. Intraperitoneal injection of bicuculline (0.5 and 1 mg/kg) decreased %MPE and AUC of %MPE, suggesting hyperalgesia. Moreover, muscimol by reducing the immobility time of the FST elicited an antidepressant-like response but bicuculline by enhancing the immobility time of the FST caused a depressant-like response. Intracerebroventricular (i.c.v.) microinjection of histamine (5 µg/mouse) enhanced %MPE and AUC of %MPE. i.c.v. infusion of histamine (2.5 and 5 µg/mouse) decreased immobility time in the FST. Co-administration of different doses of histamine along with a sub-threshold dose of muscimol potentiated antinociceptive and antidepressant-like responses produced by histamine. Cotreatment of different doses of histamine plus a noneffective dose of bicuculline reversed antinociception and antidepressant-like effects elicited by histamine. Cotreatment of histamine, muscimol, and bicuculline reversed antinociceptive and antidepressant-like behaviors induced by the drugs. The results demonstrated additive antinociceptive and antidepressant-like effects between histamine and muscimol in mice. In conclusion, our results indicated an interaction between the histaminergic and GABAergic systems in the modulation of pain and depression-like behaviors.
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Affiliation(s)
- Matin Baghani
- Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences
| | - Farzan Fathalizade
- Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences
| | - Fatemeh Khakpai
- Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University
| | - Soheila Fazli-Tabaei
- Department of Physiology, Faculty of Medicine, Tehran Medical Sciences, Islamic Azad University
| | - Mohammad-Reza Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences
- Department of Neuroendocrinology, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
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Cáceres ARR, Cardone DA, Sanhueza MDLÁ, Bosch IM, Cuello-Carrión FD, Rodriguez GB, Scotti L, Parborell F, Halperin J, Laconi MR. Local effect of allopregnanolone in rat ovarian steroidogenesis, follicular and corpora lutea development. Sci Rep 2024; 14:6402. [PMID: 38493224 PMCID: PMC10944484 DOI: 10.1038/s41598-024-57102-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 03/14/2024] [Indexed: 03/18/2024] Open
Abstract
Allopregnanolone (ALLO) is a known neurosteroid and a progesterone metabolite synthesized in the ovary, CNS, PNS, adrenals and placenta. Its role in the neuroendocrine control of ovarian physiology has been studied, but its in situ ovarian effects are still largely unknown. The aims of this work were to characterize the effects of intrabursal ALLO administration on different ovarian parameters, and the probable mechanism of action. ALLO administration increased serum progesterone concentration and ovarian 3β-HSD2 while decreasing 20α-HSD mRNA expression. ALLO increased the number of atretic follicles and the number of positive TUNEL granulosa and theca cells, while decreasing positive PCNA immunostaining. On the other hand, there was an increase in corpora lutea diameter and PCNA immunostaining, whereas the count of TUNEL-positive luteal cells decreased. Ovarian angiogenesis and the immunohistochemical expression of GABAA receptor increased after ALLO treatment. To evaluate if the ovarian GABAA receptor was involved in these effects, we conducted a functional experiment with a specific antagonist, bicuculline. The administration of bicuculline restored the number of atretic follicles and the diameter of corpora lutea to normal values. These results show the actions of ALLO on the ovarian physiology of the female rat during the follicular phase, some of them through the GABAA receptor. Intrabursal ALLO administration alters several processes of the ovarian morpho-physiology of the female rat, related to fertility and oocyte quality.
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Affiliation(s)
- Antonella Rosario Ramona Cáceres
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET Mendoza), Av. Ruiz Leal s/n Parque General San Martín, CP 5500, Mendoza, Argentina
- Facultad de Ingeniería y Facultad de Ciencias Médicas, Universidad de Mendoza, Mendoza, Argentina
| | - Daniela Alejandra Cardone
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET Mendoza), Av. Ruiz Leal s/n Parque General San Martín, CP 5500, Mendoza, Argentina
| | - María de Los Ángeles Sanhueza
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET Mendoza), Av. Ruiz Leal s/n Parque General San Martín, CP 5500, Mendoza, Argentina
| | | | - Fernando Darío Cuello-Carrión
- Laboratorio de Oncología, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET Mendoza), Mendoza, Argentina
| | | | - Leopoldina Scotti
- Ovarian Pathophysiology Studies Laboratory, Institute of Experimental Biology and Medicine (IByME) - CONICET, Buenos Aires, Argentina
| | - Fernanda Parborell
- Ovarian Pathophysiology Studies Laboratory, Institute of Experimental Biology and Medicine (IByME) - CONICET, Buenos Aires, Argentina
| | - Julia Halperin
- Centro de Estudios Biomédicos Básicos, Aplicados y Desarrollo (CEBBAD), Universidad Maimónides, Ciudad Autónoma de Buenos Aires, Argentina
| | - Myriam Raquel Laconi
- Laboratorio de Fisiopatología Ovárica, Instituto de Medicina y Biología Experimental de Cuyo (IMBECU - CONICET Mendoza), Av. Ruiz Leal s/n Parque General San Martín, CP 5500, Mendoza, Argentina.
- Facultad de Ingeniería y Facultad de Ciencias Médicas, Universidad de Mendoza, Mendoza, Argentina.
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Uribe-Mariño A, Falconi-Sobrinho LL, Castiblanco-Urbina MA, Pigatto GR, Ullah F, da Silva JA, Coimbra NC. Alpha 1- and Beta-norepinephrinergic receptors of dorsomedial and ventromedial hypothalamic nuclei modulate panic attack-like defensive behaviour elicited by diencephalic GABAergic neurotransmission disinhibition. Pharmacol Biochem Behav 2024; 236:173710. [PMID: 38262489 DOI: 10.1016/j.pbb.2024.173710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/25/2024]
Abstract
Gamma-aminobutyric acid (GABA) disinhibition in medial hypothalamus (MH) nuclei of rats elicits some defensive reactions that are considered panic attack-like behaviours. Recent evidence showed that the norepinephrine-mediated system modulates fear-related defensive behaviours organised by MH neurons at least in part via noradrenergic receptors recruitment on midbrain tegmentum. However, it is unknown whether noradrenergic receptors of the MH also modulate the panic attack-like reactions. The aim of this work was to investigate the distribution of noradrenergic receptors in MH, and the effects of either α1-, α2- or β-noradrenergic receptors blockade in the MH on defensive behaviours elaborated by hypothalamic nuclei. Defensive behaviours were evaluated after the microinjection of the selective GABAA receptor antagonist bicuculline into the MH that was preceded by microinjection of either WB4101, RX821002, propranolol (α1-, α2- and β-noradrenergic receptor selective antagonists, respectively), or physiological saline into the MH of male Wistar rats. The α1-, α2- and β-noradrenergic receptors were found in neuronal perikarya of all MH nuclei, and the α2-noradrenergic receptor were also found on glial cells mainly situated in the ventrolateral division of the ventromedial hypothalamic nucleus. The α1- and β-noradrenergic receptors blockade in the MH decreased defensive attention and escape reactions elicited by the intra-MH microinjections of bicuculline. These findings suggest that, despite the profuse distributions of α1-, α2- and β-noradrenergic receptors in the MH, both α1- and β-noradrenergic receptor- rather than α2-noradrenergic receptor-signalling in MH are critical for the neuromodulation of panic-like behaviour.
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Affiliation(s)
- Andrés Uribe-Mariño
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil
| | - Luiz Luciano Falconi-Sobrinho
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil
| | - Maria Angélica Castiblanco-Urbina
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil
| | - Glauce Regina Pigatto
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil
| | - Farhad Ullah
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Department of Animal Sciences, Quaid-i-Azam University, 45320 Islamabad, Pakistan; Department of Eastern Medicine and Surgery, School of Medical and Health Sciences of the University of Poonch Rawalakot, Azad Jammu and Kashmir, Pakistan
| | - Juliana Almeida da Silva
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil
| | - Norberto Cysne Coimbra
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; NAP-USP-Neurobiology of Emotions Research Centre (NuPNE), Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), Av. Bandeirantes, 3900, Ribeirão Preto 14049-900, São Paulo, Brazil; Behavioural Neurosciences Institute (INeC), Avenida do Café, 2450, Ribeirão Preto 14220-030, São Paulo, Brazil..
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Cowgill J, Fan C, Haloi N, Tobiasson V, Zhuang Y, Howard RJ, Lindahl E. Structure and dynamics of differential ligand binding in the human ρ-type GABA A receptor. Neuron 2023; 111:3450-3464.e5. [PMID: 37659407 DOI: 10.1016/j.neuron.2023.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 09/04/2023]
Abstract
The neurotransmitter γ-aminobutyric acid (GABA) drives critical inhibitory processes in and beyond the nervous system, partly via ionotropic type-A receptors (GABAARs). Pharmacological properties of ρ-type GABAARs are particularly distinctive, yet the structural basis for their specialization remains unclear. Here, we present cryo-EM structures of a lipid-embedded human ρ1 GABAAR, including a partial intracellular domain, under apo, inhibited, and desensitized conditions. An apparent resting state, determined first in the absence of modulators, was recapitulated with the specific inhibitor (1,2,5,6-tetrahydropyridin-4-yl)methylphosphinic acid and blocker picrotoxin and provided a rationale for bicuculline insensitivity. Comparative structures, mutant recordings, and molecular simulations with and without GABA further explained the sensitized but slower activation of ρ1 relative to canonical subtypes. Combining GABA with picrotoxin also captured an apparent uncoupled intermediate state. This work reveals structural mechanisms of gating and modulation with applications to ρ-specific pharmaceutical design and to our biophysical understanding of ligand-gated ion channels.
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Affiliation(s)
- John Cowgill
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden
| | - Chen Fan
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden
| | - Nandan Haloi
- Department of Applied Physics, SciLifeLab, KTH Royal Institute of Technology, 17121 Solna, Sweden
| | - Victor Tobiasson
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden
| | - Yuxuan Zhuang
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden
| | - Rebecca J Howard
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden.
| | - Erik Lindahl
- Department of Biochemistry and Biophysics, SciLifeLab, Stockholm University, 17121 Solna, Sweden; Department of Applied Physics, SciLifeLab, KTH Royal Institute of Technology, 17121 Solna, Sweden.
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Devereaux MEM, Pamenter ME. Adenosine and γ-aminobutyric acid partially regulate metabolic and ventilatory responses of Damaraland mole-rats to acute hypoxia. J Exp Biol 2023; 226:jeb246186. [PMID: 37694288 PMCID: PMC10565114 DOI: 10.1242/jeb.246186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 09/01/2023] [Indexed: 09/12/2023]
Abstract
Fossorial Damaraland mole-rats (Fukomys damarensis) mount a robust hypoxic metabolic response (HMR) but a blunted hypoxic ventilatory response (HVR) to acute hypoxia. Although these reflex physiological responses have been described previously, the underlying signalling pathways are entirely unknown. Of particular interest are contributions from γ-aminobutyric acid (GABA), which is the primary inhibitory neurotransmitter in the nervous system of most adult mammals, and adenosine, the accumulation of which increases during hypoxia as a breakdown product of ATP. Therefore, we hypothesized that GABAergic and/or adenosinergic signalling contributes to the blunted HVR and robust HMR in Damaraland mole-rats. To test this hypothesis, we injected adult animals with saline alone (controls), or 100 mg kg-1 aminophylline or 1 mg kg-1 bicuculline, to block adenosine or GABAA receptors, respectively. We then used respirometry, plethysmography and thermal RFID probes to non-invasively measure metabolic, ventilator and thermoregulatory responses, respectively, to acute hypoxia (1 h in 5 or 7% O2) in awake and freely behaving animals. We found that bicuculline had relatively minor effects on metabolism and thermoregulation but sensitized ventilation such that the HVR became manifest at 7% instead of 5% O2 and was greater in magnitude. Aminophylline increased metabolic rate, ventilation and body temperature in normoxia, and augmented the HMR and HVR. Taken together, these findings indicate that adenosinergic and GABAergic signalling play important roles in mediating the robust HMR and blunted HVR in Damaraland mole-rats.
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Affiliation(s)
| | - Matthew E. Pamenter
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, ON K1H 8M5, Canada
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Poggio F, Brofiga M, Callegari F, Tedesco M, Massobrio P. Developmental conditions and culture medium influence the neuromodulated response of in vitro cortical networks. Annu Int Conf IEEE Eng Med Biol Soc 2023; 2023:1-4. [PMID: 38083479 DOI: 10.1109/embc40787.2023.10340933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
Goal of this work is to show how the developmental conditions of in vitro neuronal networks influence the effect of drug delivery. The proposed experimental neuronal model consists of dissociated cortical neurons plated to Micro-Electrode Arrays (MEAs) and grown according to different conditions (i.e., by varying both the adopted culture medium and the number of days needed to let the network grow before performing the chemical modulation). We delivered rising amount of bicuculline (BIC), a competitive antagonist of GABAA receptors, and we computed the firing rate dose-response curve for each culture. We found that networks matured in BrainPhys for 18 days in vitro exhibited a decreasing firing trend as a function of the BIC concentration, quantified by an average IC50 (i.e., half maximal inhibitory concentration) of 4.64 ± 4.02 µM. On the other hand, both cultures grown in the same medium for 11 days, and ones matured in Neurobasal for 18 days displayed an increasing firing rate when rising amounts of BIC were delivered, characterized by average EC50 values (i.e., half maximal excitatory concentration) of 0.24 ± 0.05 µM and 0.59 ± 0.46 µM, respectively.Clinical Relevance- This research proves the relevance of the experimental factors that can influence the network development as key variables when developing a neuronal model to conduct drug delivery in vitro, simulating the in vivo environment. Our findings suggest that not considering the consequences of the chosen growing conditions when performing in vitro pharmacological studies could lead to incomplete predictions of the chemically induced alterations.
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Mota CMD, Siler DA, Burchiel KJ, Madden CJ. Acute deep brain stimulation of the paraventricular nucleus of the hypothalamus increases brown adipose tissue thermogenesis in rats. Neurosci Lett 2023; 799:137130. [PMID: 36792026 PMCID: PMC10069326 DOI: 10.1016/j.neulet.2023.137130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/10/2023] [Accepted: 02/11/2023] [Indexed: 02/15/2023]
Abstract
Brown adipose tissue (BAT) activity is controlled by the sympathetic nervous system. Activation of BAT has shown significant promise in preclinical studies to elicit weight loss. Since the hypothalamic paraventricular nucleus (PVN) contributes to the regulation of BAT thermogenic activity, we sought to determine the effects of electrical stimulation of the PVN as a model of deep brain stimulation (DBS) for increasing BAT sympathetic nerve activity (SNA). The rostral raphe pallidus area (rRPa) was also chosen as a target for DBS since it contains the sympathetic premotor neurons for BAT. Electrical stimulation (100 µA, 100 µs, 100 Hz, for 5 min at a 50 % duty cycle) of the PVN increased BAT SNA and BAT thermogenesis. These effects were prevented by a local nanoinjection of bicuculline, a GABAA receptor antagonist. We suggest that electrical stimulation of the PVN elicited local release of GABA, which inhibited BAT sympathoinhibitory neurons in PVN, thereby releasing a restraint on BAT SNA. Electrical stimulation of the rRPa inhibited BAT thermogenesis and this was prevented by a local nanoinjection of bicuculline, suggesting that local release of GABA suppressed BAT SNA. Electrical stimulation of the PVN activates BAT metabolism via a mechanism that may include activation of local GABAA receptors. These findings contribute to our understanding of the mechanisms underlying the effects of DBS in the regulation of fat metabolism and provide a foundation for further DBS studies targeting hypothalamic circuits regulating BAT thermogenesis as a therapy for obesity.
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Affiliation(s)
- Clarissa M D Mota
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States
| | - Dominic A Siler
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States
| | - Kim J Burchiel
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States
| | - Christopher J Madden
- Department of Neurological Surgery, Oregon Health and Science University, Portland, OR, United States.
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Pontes RB, Nishi EE, Crajoinas RO, Milanez MIO, Girardi ACC, Campos RR, Bergamaschi CT. Relative Contribution of Blood Pressure and Renal Sympathetic Nerve Activity to Proximal Tubular Sodium Reabsorption via NHE3 Activity. Int J Mol Sci 2022; 24:ijms24010349. [PMID: 36613793 PMCID: PMC9820392 DOI: 10.3390/ijms24010349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/17/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
We examined the effects of an acute increase in blood pressure (BP) and renal sympathetic nerve activity (rSNA) induced by bicuculline (Bic) injection in the paraventricular nucleus of hypothalamus (PVN) or the effects of a selective increase in rSNA induced by renal nerve stimulation (RNS) on the renal excretion of sodium and water and its effect on sodium-hydrogen exchanger 3 (NHE3) activity. Uninephrectomized anesthetized male Wistar rats were divided into three groups: (1) Sham; (2) Bic PVN: (3) RNS + Bic injection into the PVN. BP and rSNA were recorded, and urine was collected prior and after the interventions in all groups. RNS decreased sodium (58%) and water excretion (53%) independently of BP changes (p < 0.05). However, after Bic injection in the PVN during RNS stimulation, the BP and rSNA increased by 30% and 60% (p < 0.05), respectively, diuresis (5-fold) and natriuresis (2.3-fold) were increased (p < 0.05), and NHE3 activity was significantly reduced, independently of glomerular filtration rate changes. Thus, an acute increase in the BP overcomes RNS, leading to diuresis, natriuresis, and NHE3 activity inhibition.
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Affiliation(s)
- Roberto B. Pontes
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Erika E. Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Renato O. Crajoinas
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo 01246-903, Brazil
| | - Maycon I. O. Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Adriana C. C. Girardi
- Heart Institute (InCor), University of São Paulo Medical School, São Paulo 01246-903, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
| | - Cassia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo 04021-001, Brazil
- Correspondence:
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10
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Zhang C, Zhou Y, Zheng J, Ning N, Liu H, Jiang W, Yu X, Mu K, Li Y, Guo W, Hu H, Li J, Chen D. Inhibition of GABAA receptors in intestinal stem cells prevents chemoradiotherapy-induced intestinal toxicity. J Exp Med 2022; 219:213480. [PMID: 36125780 PMCID: PMC9499828 DOI: 10.1084/jem.20220541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 08/07/2022] [Accepted: 08/26/2022] [Indexed: 11/04/2022] Open
Abstract
Lethal intestinal tissue toxicity is a common side effect and a dose-limiting factor in chemoradiotherapy. Chemoradiotherapy can trigger DNA damage and induce P53-dependent apoptosis in LGR5+ intestinal stem cells (ISCs). Gamma-aminobutyric acid (GABA) and its A receptors (GABAAR) are present in the gastrointestinal tract. However, the functioning of the GABAergic system in ISCs is poorly defined. We found that GABAAR α1 (GABRA1) levels increased in the murine intestine after chemoradiotherapy. GABRA1 depletion in LGR5+ ISCs protected the intestine from chemoradiotherapy-induced P53-dependent apoptosis and prolonged animal survival. The administration of bicuculline, a GABAAR antagonist, prevented chemoradiotherapy-induced ISC loss and intestinal damage without reducing the chemoradiosensitivity of tumors. Mechanistically, it was associated with the reduction of reactive oxygen species-induced DNA damage via the L-type voltage-dependent Ca2+ channels. Notably, flumazenil, a GABAAR antagonist approved by the U.S. Food and Drug Administration, rescued human colonic organoids from chemoradiotherapy-induced toxicity. Therefore, flumazenil may be a promising drug for reducing the gastrointestinal side effects of chemoradiotherapy.
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Affiliation(s)
- Cuiyu Zhang
- Department of Physiology, School of Basic Medical Sciences, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Yuping Zhou
- Department of Cardiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Junjie Zheng
- Department of Physiology, School of Basic Medical Sciences, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Nannan Ning
- Department of Clinical Laboratory, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Haining Liu
- Department of Liver Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wenyang Jiang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing, China
| | - Xin Yu
- Department of Biotherapy, State Key laboratory of Biotherapy and cancer center, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Kun Mu
- Department of Pathology, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Yan Li
- Translational Medical Research Center, The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Wei Guo
- Department of Colorectal Surgery, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Huili Hu
- Department of Systems Biomedicine and Research Center of Stem Cell and Regenerative Medicine, Shandong University Cheeloo Medical College, School of Basic Medical Sciences, Jinan, China
| | - Jingxin Li
- Department of Physiology, School of Basic Medical Sciences, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- Jingxin Li:
| | - Dawei Chen
- Department of Physiology, School of Basic Medical Sciences, Qilu Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
- Laboratory of Medical Chemistry, GIGA-Stem Cells, Faculty of Medicine, University of Liège, CHU, Sart-Tilman, Liège, Belgium
- Correspondence to Dawei Chen:
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11
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Jiménez-Dinamarca I, Reyes-Lizana R, Lemunao-Inostroza Y, Cárdenas K, Castro-Lazo R, Peña F, Lucero CM, Prieto-Villalobos J, Retamal MA, Orellana JA, Stehberg J. GABAergic Regulation of Astroglial Gliotransmission through Cx43 Hemichannels. Int J Mol Sci 2022; 23:13625. [PMID: 36362410 PMCID: PMC9656947 DOI: 10.3390/ijms232113625] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 09/30/2022] [Accepted: 10/09/2022] [Indexed: 02/12/2024] Open
Abstract
Gamma-Aminobutyric acid (GABA) is the primary inhibitory neurotransmitter in the brain. It is produced by interneurons and recycled by astrocytes. In neurons, GABA activates the influx of Cl- via the GABAA receptor or efflux or K+ via the GABAB receptor, inducing hyperpolarization and synaptic inhibition. In astrocytes, the activation of both GABAA and GABAB receptors induces an increase in intracellular Ca2+ and the release of glutamate and ATP. Connexin 43 (Cx43) hemichannels are among the main Ca2+-dependent cellular mechanisms for the astroglial release of glutamate and ATP. However, no study has evaluated the effect of GABA on astroglial Cx43 hemichannel activity and Cx43 hemichannel-mediated gliotransmission. Here we assessed the effects of GABA on Cx43 hemichannel activity in DI NCT1 rat astrocytes and hippocampal brain slices. We found that GABA induces a Ca2+-dependent increase in Cx43 hemichannel activity in astrocytes mediated by the GABAA receptor, as it was blunted by the GABAA receptor antagonist bicuculline but unaffected by GABAB receptor antagonist CGP55845. Moreover, GABA induced the Cx43 hemichannel-dependent release of glutamate and ATP, which was also prevented by bicuculline, but unaffected by CGP. Gliotransmission in response to GABA was also unaffected by pannexin 1 channel blockade. These results are discussed in terms of the possible role of astroglial Cx43 hemichannel-mediated glutamate and ATP release in regulating the excitatory/inhibitory balance in the brain and their possible contribution to psychiatric disorders.
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Affiliation(s)
- Ivanka Jiménez-Dinamarca
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
| | - Rachel Reyes-Lizana
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
| | - Yordan Lemunao-Inostroza
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
| | - Kevin Cárdenas
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
| | - Raimundo Castro-Lazo
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
| | - Francisca Peña
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Universidad del Desarrollo–Clínica Alemana, Santiago 7780272, Chile
| | - Claudia M. Lucero
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Juan Prieto-Villalobos
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Mauricio Antonio Retamal
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina, Universidad del Desarrollo–Clínica Alemana, Santiago 7780272, Chile
| | - Juan Andrés Orellana
- Departamento de Neurología, Escuela de Medicina and Centro Interdisciplinario de Neurociencias, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 8330024, Chile
| | - Jimmy Stehberg
- Laboratorio de Neurobiología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad Andres Bello, Santiago 8370186, Chile
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12
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Bhattacharya D, Bartley AF, Li Q, Dobrunz LE. Bicuculline restores frequency-dependent hippocampal I/E ratio and circuit function in PGC-1ɑ null mice. Neurosci Res 2022; 184:9-18. [PMID: 35842011 PMCID: PMC10865982 DOI: 10.1016/j.neures.2022.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 06/22/2022] [Accepted: 07/12/2022] [Indexed: 10/31/2022]
Abstract
Altered inhibition/excitation (I/E) balance contributes to various brain disorders. Dysfunctional GABAergic interneurons enhance or reduce inhibition, resulting in I/E imbalances. Differences in short-term plasticity between excitation and inhibition cause frequency-dependence of the I/E ratio, which can be altered by GABAergic dysfunction. However, it is unknown whether I/E imbalances can be rescued pharmacologically using a single dose when the imbalance magnitude is frequency-dependent. Loss of PGC-1α (peroxisome proliferator activated receptor γ coactivator 1α) causes transcriptional dysregulation in hippocampal GABAergic interneurons. PGC-1α-/- slices have enhanced baseline inhibition onto CA1 pyramidal cells, causing increased I/E ratio and impaired circuit function. High frequency stimulation reduces the I/E ratio and recovers circuit function in PGC-1α-/- slices. Here we tested if using a low dose of bicuculline that can restore baseline I/E ratio can also rescue the frequency-dependent I/E imbalances in these mice. Remarkably, bicuculline did not reduce the I/E ratio below that of wild type during high frequency stimulation. Interestingly, bicuculline enhanced the paired-pulse ratio (PPR) of disynaptic inhibition without changing the monosynaptic inhibition PPR, suggesting that bicuculline modifies interneuron recruitment and not GABA release. Bicuculline improved CA1 output in PGC-1α-/- slices, enhancing EPSP-spike coupling to wild type levels at high and low frequencies. Our results show that it is possible to rescue frequency-dependent I/E imbalances in an animal model of transcriptional dysregulation with a single treatment.
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Affiliation(s)
- Dwipayan Bhattacharya
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Aundrea F Bartley
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Qin Li
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States
| | - Lynn E Dobrunz
- Department of Neurobiology, Civitan International Research Center, and Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL, United States.
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13
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Bortz DM, Feistritzer CM, Power CC, Grace AA. Medial septum activation improves strategy switching once strategies are well-learned via bidirectional regulation of dopamine neuron population activity. Neuropsychopharmacology 2022; 47:2090-2100. [PMID: 35871093 PMCID: PMC9556587 DOI: 10.1038/s41386-022-01387-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/17/2022] [Accepted: 07/11/2022] [Indexed: 11/08/2022]
Abstract
Strategy switching is a form of cognitive flexibility that requires inhibiting a previously successful strategy and switching to a new strategy of a different categorical modality. It is dependent on dopamine (DA) receptor activation and release in ventral striatum and prefrontal cortex, two primary targets of ventral tegmental area (VTA) DA projections. Although the circuitry that underlies strategy switching early in learning has been studied, few studies have examined it after extended discrimination training. This may be important as DA activity and release patterns change across learning, with several studies demonstrating a critical role for substantia nigra pars compacta (SNc) DA activity and release once behaviors are well-learned. We have demonstrated that medial septum (MS) activation simultaneously increased VTA and decreased SNc DA population activity, as well as improved reversal learning via these actions on DA activity. We hypothesized that MS activation would improve strategy switching both early in learning and after extended training through its ability to increase VTA DA population activity and decrease SNc DA population activity, respectively. We chemogenetically activated the MS of male and female rats and measured their performance on an operant-based strategy switching task following 1, 10, or 15 days of discrimination training. Contrary to our hypothesis, MS activation did not affect strategy switching after 1 day of discrimination training. MS activation improved strategy switching after 10 days of training, but only in females. MS activation improved strategy switching in both sexes after 15 days of training. Infusion of bicuculline into the ventral subiculum (vSub) inhibited the MS-mediated decrease in SNc DA population activity and attenuated the improvement in strategy switching. Intra-vSub infusion of scopolamine inhibited the MS-mediated increase in VTA DA population activity but did not affect the improvement in strategy switching. Intra-vSub infusion of both bicuculline and scopolamine inhibited the MS-mediated effects on DA population activity in both the SNc and VTA and completely prevented the improvement in strategy switching. These data indicate that MS activation improves strategy switching once the original strategy has been sufficiently well-learned, and that this may occur via the MS's regulation of DA neuron responsivity.
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Affiliation(s)
- David M Bortz
- Department of Neuroscience, Psychiatry, and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Catalina M Feistritzer
- Department of Neuroscience, Psychiatry, and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Cassidy C Power
- Department of Neuroscience, Psychiatry, and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - Anthony A Grace
- Department of Neuroscience, Psychiatry, and Psychology, Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
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14
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Ohta Y, Murakami TE, Kawahara M, Haruta M, Takehara H, Tashiro H, Sasagawa K, Ohta J, Akay M, Akay YM. Investigating the Influence of GABA Neurons on Dopamine Neurons in the Ventral Tegmental Area Using Optogenetic Techniques. Int J Mol Sci 2022; 23:ijms23031114. [PMID: 35163036 PMCID: PMC8834722 DOI: 10.3390/ijms23031114] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 01/18/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
Dopamine (DA) is the key regulator of reward behavior. The DA neurons in the ventral tegmental area (VTA) and their projection areas, which include the prefrontal cortex (PFC), nucleus accumbens (NAc), and amygdala, play a primary role in the process of reward-driven behavior induced by the drugs of addiction, including nicotine and alcohol. In our previous study, we developed a novel platform consisting of micro-LED array devices to stimulate a large area of the brain of rats and monkeys with photo-stimulation and a microdialysis probe to estimate the DA release in the PFC. Our results suggested that the platform was able to detect the increased level of dopamine in the PFC in response to the photo-stimulation of both the PFC and VTA. In this study, we used this platform to photo-stimulate the VTA neurons in both ChrimsonR-expressing (non-specific) wild and dopamine transporter (DAT)-Cre (dopamine specific) mice, and measured the dopamine release in the nucleus accumbens shell (NAcShell). We measured the DA release in the NAcShell in response to optogenetic stimulation of the VTA neurons and investigated the effect of GABAergic neurons on dopaminergic neurons by histochemical studies. Comparing the photo-stimulation frequency of 2 Hz with that of 20 Hz, the change in DA concentration at the NAcShell was greater at 20 Hz in both cases. When ChrimsonR was expressed specifically for DA, the release of DA at the NAcShell increased in response to photo-stimulation of the VTA. In contrast, when ChrimsonR was expressed non-specifically, the amount of DA released was almost unchanged upon photo-stimulation. However, for nonspecifically expressed ChrimsonR, intraperitoneal injection of bicuculline, a competitive antagonist at the GABA-binding site of the GABAA receptor, also significantly increased the release of DA at the NAcShell in response to photo-stimulation of the VTA. The results of immunochemical staining confirm that GABAergic neurons in the VTA suppress DA activation, and also indicate that alterations in GABAergic neurons may have serious downstream effects on DA activity, NAcShell release, and neural adaptation of the VTA. This study also confirms that optogenetics technology is crucial to study the relationship between the mesolimbic dopaminergic and GABAergic neurons in a neural-specific manner.
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Affiliation(s)
- Yasumi Ohta
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Takaaki E. Murakami
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Mamiko Kawahara
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Makito Haruta
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Hironari Takehara
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Hiroyuki Tashiro
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Kiyotaka Sasagawa
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Jun Ohta
- Nara Institute of Science and Technology, 8916-5, Ikoma 630-0101, Japan; (Y.O.); (T.E.M.); (M.K.); (M.H.); (H.T.); (H.T.); (K.S.); (J.O.)
| | - Metin Akay
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, USA;
| | - Yasemin M. Akay
- Department of Biomedical Engineering, University of Houston, Houston, TX 77204-5060, USA;
- Correspondence:
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15
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Matsumoto D, Ushio S, Wada Y, Noda Y, Esumi S, Izushi Y, Kitamura Y, Sendo T. Bumetanide prevents diazepam-modified anxiety-like behavior in lipopolysaccharide-treated mice. Eur J Pharmacol 2021; 904:174195. [PMID: 34004209 DOI: 10.1016/j.ejphar.2021.174195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/27/2021] [Accepted: 05/12/2021] [Indexed: 10/21/2022]
Abstract
Benzodiazepine receptor agonists are widely prescribed therapeutic agents that alter gamma-aminobutyric acid (GABA)A receptor activity and have anxiolytic effects. Post-operative use of benzodiazepines is a risk factor of delirium. Inflammatory conditions alter the anxiolytic effects of benzodiazepine. We investigated the effect of diazepam, a typical benzodiazepine anxiolytic, on changes in the emotional behavior of mice in a hole-board test after lipopolysaccharide (LPS) treatment. Diazepam dose-dependently increased the number of head-dips at doses that did not alter locomotor activity; however, diazepam dose-dependently significantly decreased the number of head-dips at doses that did not alter locomotor activity in LPS-treated mice. Flumazenil, a benzodiazepine receptor antagonist, normalized the decrease in head-dipping behavior caused by diazepam treatment in normal and LPS-treated mice. The decrease of the head-dipping effect caused by diazepam was attenuated by minocycline in LPS-treated mice. We further found that the decrease in head-dipping behavior caused by diazepam was blocked by bumetanide, a Na+-K+-2Cl- cotransporter isoform 1 (NKCC1) antagonist, in LPS-treated mice. These findings suggest that diazepam induces the anxiety-like behavior under inflammation conditions, and may cause the GABAA receptor dysfunction associated with the chloride plasticity mediated by NKCC1, which contributes to benzodiazepine-induced delirium after surgery.
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Affiliation(s)
- Daiki Matsumoto
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Soichiro Ushio
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Yudai Wada
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Yukiko Noda
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan
| | - Satoru Esumi
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
| | - Yasuhisa Izushi
- Department of Pharmacotherapy, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama, 703-8516, Japan
| | - Yoshihisa Kitamura
- Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan; Department of Pharmacotherapy, School of Pharmacy, Shujitsu University, 1-6-1 Nishigawara, Naka-ku, Okayama, 703-8516, Japan.
| | - Toshiaki Sendo
- Department of Clinical Pharmacy, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama, 700-8558, Japan; Department of Pharmacy, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan
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16
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Tamim I, Chung DY, de Morais AL, Loonen ICM, Qin T, Misra A, Schlunk F, Endres M, Schiff SJ, Ayata C. Spreading depression as an innate antiseizure mechanism. Nat Commun 2021; 12:2206. [PMID: 33850125 PMCID: PMC8044138 DOI: 10.1038/s41467-021-22464-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 03/15/2021] [Indexed: 12/16/2022] Open
Abstract
Spreading depression (SD) is an intense and prolonged depolarization in the central nervous systems from insect to man. It is implicated in neurological disorders such as migraine and brain injury. Here, using an in vivo mouse model of focal neocortical seizures, we show that SD may be a fundamental defense against seizures. Seizures induced by topical 4-aminopyridine, penicillin or bicuculline, or systemic kainic acid, culminated in SDs at a variable rate. Greater seizure power and area of recruitment predicted SD. Once triggered, SD immediately suppressed the seizure. Optogenetic or KCl-induced SDs had similar antiseizure effect sustained for more than 30 min. Conversely, pharmacologically inhibiting SD occurrence during a focal seizure facilitated seizure generalization. Altogether, our data indicate that seizures trigger SD, which then terminates the seizure and prevents its generalization.
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Affiliation(s)
- Isra Tamim
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - David Y Chung
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Andreia Lopes de Morais
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Inge C M Loonen
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tao Qin
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Amrit Misra
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Frieder Schlunk
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - Matthias Endres
- Charité-Universitätsmedizin Berlin, Klinik und Hochschulambulanz für Neurologie und Centrum für Schlaganfallforschung Berlin (CSB), Berlin, Germany
| | - Steven J Schiff
- Center for Neural Engineering, Departments of Engineering Science and Mechanics and Physics, The Pennsylvania State University, State College, PA, USA
| | - Cenk Ayata
- Neurovascular Research Unit, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
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17
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Zapukhliak O, Netsyk O, Romanov A, Maximyuk O, Oz M, Holmes GL, Krishtal O, Isaev D. Mecamylamine inhibits seizure-like activity in CA1-CA3 hippocampus through antagonism to nicotinic receptors. PLoS One 2021; 16:e0240074. [PMID: 33711021 PMCID: PMC7954330 DOI: 10.1371/journal.pone.0240074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 03/02/2021] [Indexed: 11/18/2022] Open
Abstract
Cholinergic modulation of hippocampal network function is implicated in multiple behavioral and cognitive states. Activation of nicotinic and muscarinic acetylcholine receptors affects neuronal excitability, synaptic transmission and rhythmic oscillations in the hippocampus. In this work, we studied the ability of the cholinergic system to sustain hippocampal epileptiform activity independently from glutamate and GABA transmission. Simultaneous CA3 and CA1 field potential recordings were obtained during the perfusion of hippocampal slices with the aCSF containing AMPA, NMDA and GABA receptor antagonists. Under these conditions, spontaneous epileptiform discharges synchronous between CA3 and CA1 were recorded. Epileptiform discharges were blocked by addition of the calcium-channel blocker Cd2+ and disappeared in CA1 after a surgical cut between CA3 and CA1. Cholinergic antagonist mecamylamine abolished CA3-CA1 synchronous epileptiform discharges, while antagonists of α7 and α4β2 nAChRs, MLA and DhβE, had no effect. Our results suggest that activation of nicotinic acetylcholine receptors can sustain CA3-CA1 synchronous epileptiform activity independently from AMPA, NMDA and GABA transmission. In addition, mecamylamine, but not α7 and α4β2 nAChRs antagonists, reduced bicuculline-induced seizure-like activity. The ability of mecamylamine to decrease hippocampal network synchronization might be associated with its therapeutic effects in a wide variety of CNS disorders including addiction, depression and anxiety.
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Affiliation(s)
- Olha Zapukhliak
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Olga Netsyk
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Artur Romanov
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Oleksandr Maximyuk
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Murat Oz
- Faculty of Pharmacy, Department of Pharmacology and Therapeutics, Kuwait University, Safat, Kuwait
| | - Gregory L. Holmes
- Neurological Sciences, Larner College of Medicine, University of Vermont, Burlington, Vermont, United States of America
| | - Oleg Krishtal
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
| | - Dmytro Isaev
- Department of Cellular Membranology, Bogomoletz Institute of Physiology, Kiev, Ukraine
- * E-mail:
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18
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Sabihi S, Goodpaster C, Maurer S, Leuner B. GABA in the medial prefrontal cortex regulates anxiety-like behavior during the postpartum period. Behav Brain Res 2021; 398:112967. [PMID: 33075397 PMCID: PMC7722033 DOI: 10.1016/j.bbr.2020.112967] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/02/2020] [Accepted: 10/07/2020] [Indexed: 01/22/2023]
Abstract
The postpartum period is commonly accompanied by emotional changes, which for many new mothers includes a reduction in anxiety. Previous research in rodents has shown that the postpartum attenuation in anxiety is dependent on offspring contact and has further implicated enhanced GABAergic neurotransmission as an underlying mechanism. However, the specific brain regions where GABA acts to regulate the offspring-induced reduction in postpartum anxiety requires further investigation. Here, we test the hypothesis that offspring interactions suppress anxiety-like behavior in postpartum female rats via GABA signaling in the medial prefrontal cortex (mPFC). Our results show a postpartum reduction in anxiety-like behavior, an effect which was abolished by localized infusion of the GABAA receptor antagonist bicuculline in the mPFC. We also show that activation of GABAA receptors in the mPFC by the agonist muscimol was effective in restoring anxiolyisis in mothers separated from their pups. Lastly, we show that heightened anxiety-like behavior in pup-separated mothers was accompanied by a lower number and percentage of activated GABAergic neurons within the mPFC. Together, these results suggest that mother-offspring interactions reduce anxiety-like behavior in postpartum females via GABAA neurotransmission in the mPFC and in doing so provide insight into mechanisms that may become dysfunctional in mothers who experience high postpartum anxiety.
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Affiliation(s)
- Sara Sabihi
- Department of Psychology, The Ohio State University Columbus, OH 43210, USA
| | - Caitlin Goodpaster
- Department of Psychology, The Ohio State University Columbus, OH 43210, USA
| | - Skyler Maurer
- Department of Psychology, The Ohio State University Columbus, OH 43210, USA
| | - Benedetta Leuner
- Department of Psychology, The Ohio State University Columbus, OH 43210, USA; Department of Neuroscience, The Ohio State University Columbus, OH 43210, USA.
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19
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Abstract
Allopregnanolone, a positive modulator of GABAA receptors with antiseizure activity, has potential in the treatment of seizure emergencies. Instillation of allopregnanolone in 40% sulfobutylether-β-cyclodextrin into the nose in mice rapidly elevated the seizure threshold in the timed intravenous pentylenetetrazol (ED50, 5.6 mg/kg), picrotoxin (ED50, 5.9 mg/kg), and bicuculline seizure tests. The effect peaked at 15 min, decayed over 1 h, and was still evident in some experiments at 6 h. Intranasal allopregnanolone also delayed the onset of seizures in the maximal PTZ test. At an allopregnanolone dose (16 mg/kg) that conferred comparable effects on seizure threshold as the benzodiazepines midazolam and diazepam (both at doses of 1 mg/kg), allopregnanolone caused minimal sedation or motor toxicity in the horizontal screen test whereas both benzodiazepines produced marked behavioral impairment. In addition, intranasal allopregnanolone failed to cause loss-of-righting reflex in most animals, but when the same dose was administered intramuscularly, all animals became impaired. Intranasal allopregnanolone (10 mg/kg) caused a rapid increase in brain allopregnanolone with a Tmax of ~5 min after initiation of the intranasal delivery. High levels of allopregnanolone were recovered in the olfactory bulb (Cmax, 16,000 ng/mg) whereas much lower levels (Cmax, 670 ng/mg) were present in the remainder of the brain. We conclude that the unique ability of intranasal allopregnanolone to protect against seizures without inducing behavioral adverse effects is due in part to direct nose-to-brain delivery, with preferential transport to brain regions relevant to seizures. Benzodiazepines are commonly administered intranasally for acute seizure therapy, including for the treatment of acute repetitive seizures, but are not transported from nose-to-brain. Intranasal allopregnanolone acts with greater speed, has less propensity for adverse effects, and has the ability to overcome benzodiazepine refractoriness. This is the first study demonstrating rapid functional central nervous system activity of a nose-to-brain-delivered steroid. Intranasal delivery circumvents the poor oral bioavailability of allopregnanolone providing a route of administration permitting its evaluation as a treatment for diverse neuropsychiatric indications.
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Affiliation(s)
- Dorota Zolkowska
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
| | - Chun-Yi Wu
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA
- Bioanalysis and Pharmacokinetics Core Facility, UC Davis Medical Center, Sacramento, CA, 95817, USA
| | - Michael A Rogawski
- Department of Neurology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
- Department of Pharmacology, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
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20
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Kim JJ, Gharpure A, Teng J, Zhuang Y, Howard RJ, Zhu S, Noviello CM, Walsh RM, Lindahl E, Hibbs RE. Shared structural mechanisms of general anaesthetics and benzodiazepines. Nature 2020; 585:303-308. [PMID: 32879488 PMCID: PMC7486282 DOI: 10.1038/s41586-020-2654-5] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 06/01/2020] [Indexed: 01/17/2023]
Abstract
Most general anaesthetics and classical benzodiazepine drugs act through positive modulation of γ-aminobutyric acid type A (GABAA) receptors to dampen neuronal activity in the brain1-5. However, direct structural information on the mechanisms of general anaesthetics at their physiological receptor sites is lacking. Here we present cryo-electron microscopy structures of GABAA receptors bound to intravenous anaesthetics, benzodiazepines and inhibitory modulators. These structures were solved in a lipidic environment and are complemented by electrophysiology and molecular dynamics simulations. Structures of GABAA receptors in complex with the anaesthetics phenobarbital, etomidate and propofol reveal both distinct and common transmembrane binding sites, which are shared in part by the benzodiazepine drug diazepam. Structures in which GABAA receptors are bound by benzodiazepine-site ligands identify an additional membrane binding site for diazepam and suggest an allosteric mechanism for anaesthetic reversal by flumazenil. This study provides a foundation for understanding how pharmacologically diverse and clinically essential drugs act through overlapping and distinct mechanisms to potentiate inhibitory signalling in the brain.
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Affiliation(s)
- Jeong Joo Kim
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Anant Gharpure
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Jinfeng Teng
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Yuxuan Zhuang
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Rebecca J Howard
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
| | - Shaotong Zhu
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Colleen M Noviello
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Richard M Walsh
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
| | - Erik Lindahl
- Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Solna, Sweden
- Department of Applied Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, Solna, Sweden
| | - Ryan E Hibbs
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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21
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Al-Absi AR, Qvist P, Okujeni S, Khan AR, Glerup S, Sanchez C, Nyengaard JR. Layers II/III of Prefrontal Cortex in Df(h22q11)/+ Mouse Model of the 22q11.2 Deletion Display Loss of Parvalbumin Interneurons and Modulation of Neuronal Morphology and Excitability. Mol Neurobiol 2020; 57:4978-4988. [PMID: 32820460 DOI: 10.1007/s12035-020-02067-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/09/2020] [Indexed: 11/26/2022]
Abstract
The 22q11.2 deletion has been identified as a risk factor for multiple neurodevelopmental disorders. Behavioral and cognitive impairments are common among carriers of the 22q11.2 deletion. Parvalbumin expressing (PV+) interneurons provide perisomatic inhibition of excitatory neuronal circuits through GABAA receptors, and a deficit of PV+ inhibitory circuits may underlie a multitude of the behavioral and functional deficits in the 22q11.2 deletion syndrome. We investigated putative deficits of PV+ inhibitory circuits and the associated molecular, morphological, and functional alterations in the prefrontal cortex (PFC) of the Df(h22q11)/+ mouse model of the 22q11.2 hemizygous deletion. We detected a significant decrease in the number of PV+ interneurons in layers II/III of PFC in Df(h22q11)/+ mice together with a reduction in the mRNA and protein levels of GABAA (α3), a PV+ putative postsynaptic receptor subunit. Pyramidal neurons from the same layers further experienced morphological reorganizations of spines and dendrites. Accordingly, a decrease in the levels of the postsynaptic density protein 95 (PSD95) and a higher neuronal activity in response to the GABAA antagonist bicuculline were measured in these layers in PFC of Df(h22q11)/+ mice compared with their wild-type littermates. Our study shows that a hemizygotic deletion of the 22q11.2 locus leads to deficit in the GABAergic control of network activity and involves molecular and morphological changes in both the inhibitory and excitatory synapses of parvalbumin interneurons and pyramidal neurons specifically in layers II/III PFC.
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Affiliation(s)
- Abdel-Rahman Al-Absi
- Centre for Molecular Morphology, Section for Stereology and Microscopy; Centre for Stochastic Geometry and Advanced Bioimaging, Department of Clinical Medicine, Aarhus University, Palle Juul Jensens Boulevard, 99 8200, Aarhus N, Denmark.
| | - Per Qvist
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Aarhus, Denmark
- Centre for Integrative Sequencing, iSEQ, Aarhus University, Aarhus, Denmark
- Centre for Genomics and Personalized Medicine, CGPM, Aarhus University, Aarhus, Denmark
| | - Samora Okujeni
- Laboratory for Biomicrotechnology, Department of Microsystems Engineering IMTEK, University of Freiburg, Freiburg, Germany
| | - Ahmad Raza Khan
- Center of Functionally Integrative Neuroscience (CFIN), Aarhus University, Aarhus, Denmark
- Centre of Biomedical Research (CBMR), SGPGIMS Campus, Lucknow, India
| | - Simon Glerup
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Connie Sanchez
- Translational Neuropsychiatry Unit, Aarhus University, Aarhus, Denmark
| | - Jens R Nyengaard
- Centre for Molecular Morphology, Section for Stereology and Microscopy; Centre for Stochastic Geometry and Advanced Bioimaging, Department of Clinical Medicine, Aarhus University, Palle Juul Jensens Boulevard, 99 8200, Aarhus N, Denmark
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22
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Beagan JA, Pastuzyn ED, Fernandez LR, Guo MH, Feng K, Titus KR, Chandrashekar H, Shepherd JD, Phillips-Cremins JE. Three-dimensional genome restructuring across timescales of activity-induced neuronal gene expression. Nat Neurosci 2020; 23:707-717. [PMID: 32451484 PMCID: PMC7558717 DOI: 10.1038/s41593-020-0634-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 04/01/2020] [Indexed: 12/22/2022]
Abstract
Neuronal activation induces rapid transcription of immediate early genes (IEGs) and longer-term chromatin remodeling around secondary response genes (SRGs). Here, we use high-resolution chromosome-conformation-capture carbon-copy sequencing (5C-seq) to elucidate the extent to which long-range chromatin loops are altered during short- and long-term changes in neural activity. We find that more than 10% of loops surrounding select IEGs, SRGs, and synaptic genes are induced de novo during cortical neuron activation. IEGs Fos and Arc connect to activity-dependent enhancers via singular short-range loops that form within 20 min after stimulation, prior to peak messenger RNA levels. By contrast, the SRG Bdnf engages in both pre-existing and activity-inducible loops that form within 1-6 h. We also show that common single-nucleotide variants that are associated with autism and schizophrenia are colocalized with distinct classes of activity-dependent, looped enhancers. Our data link architectural complexity to transcriptional kinetics and reveal the rapid timescale by which higher-order chromatin architecture reconfigures during neuronal stimulation.
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Affiliation(s)
- Jonathan A Beagan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Elissa D Pastuzyn
- Department of Neurobiology and Anatomy, The University of Utah, Salt Lake City, Utah, USA
| | - Lindsey R Fernandez
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael H Guo
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, PA, USA
| | - Kelly Feng
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Katelyn R Titus
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | | | - Jason D Shepherd
- Department of Neurobiology and Anatomy, The University of Utah, Salt Lake City, Utah, USA.
- Department of Biochemistry, The University of Utah, Salt Lake City, Utah, USA.
| | - Jennifer E Phillips-Cremins
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA.
- Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Department of Genetics, University of Pennsylvania, Philadelphia, PA, USA.
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23
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Milanez MIO, Nishi EE, Rocha AA, Bergamaschi CT, Campos RR. Interaction between angiotensin II and GABA in the spinal cord regulates sympathetic vasomotor activity in Goldblatt hypertension. Neurosci Lett 2020; 728:134976. [PMID: 32304717 DOI: 10.1016/j.neulet.2020.134976] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 03/17/2020] [Accepted: 04/07/2020] [Indexed: 12/16/2022]
Abstract
Previous studies have been described changes in brain regions contributing to the sympathetic vasomotor overactivity in Goldblatt hypertension (2K1C). Furthermore, changes in the spinal cord are also involved in the cardiovascular and autonomic dysfunction in renovascular hypertension, as intrathecal (i.t.) administration of Losartan (Los) causes a robust hypotensive/sympathoinhibitory response in 2K1C but not in control rats. The present study evaluated the role of spinal γ-aminobutyric acid (GABA)-ergic inputs in the control of sympathetic vasomotor activity in the 2K1C rats. Hypertension was induced by clipping the renal artery. After six weeks, a catheter (PE-10) was inserted into the subarachnoid space and advanced to the T10-11 vertebral level in urethane-anaesthetized rats. The effects of i.t. injection of bicuculline (Bic) on blood pressure (BP), renal and splanchnic sympathetic nerve activity (rSNA and sSNA, respectively) were evaluated over 40 consecutive minutes in the presence or absence of spinal AT1 antagonism. I.t. Bic triggered a more intense pressor and sympathoexcitatory response in 2K1C rats, however, these responses were attenuated by previous i.t. Los. No differences in the gene expression of GAD 65 and GABA-A receptors subunits in the spinal cord segments were found. Thus, the sympathoexcitation induced by spinal GABA-A blockade is dependent of local AT1 receptor in 2K1C but not in control rats. Excitatory angiotensinergic inputs to sympathetic preganglionic neurons are tonic controlled by spinal GABAergic actions in Goldblatt hypertension.
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Affiliation(s)
- Maycon I O Milanez
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Erika E Nishi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Antônio A Rocha
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Cássia T Bergamaschi
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil
| | - Ruy R Campos
- Cardiovascular Division, Department of Physiology, Escola Paulista de Medicina, Universidade Federal de São Paulo, Brazil.
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24
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Liu Y, Li X, Shen X, Ivanova D, Lass G, He W, Chen Q, Yu S, Wang Y, Long H, Wang L, Lyu Q, Kuang Y, O’Byrne KT. Dynorphin and GABAA Receptor Signaling Contribute to Progesterone's Inhibition of the LH Surge in Female Mice. Endocrinology 2020; 161:5808894. [PMID: 32181477 PMCID: PMC7153819 DOI: 10.1210/endocr/bqaa036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 02/28/2020] [Indexed: 01/02/2023]
Abstract
Progesterone can block estrogen-induced luteinising hormone (LH) surge secretion and can be used clinically to prevent premature LH surges. The blocking effect of progesterone on the LH surge is mediated through its receptor in the anteroventral periventricular nucleus (AVPV) of the hypothalamus. However, the underlying mechanisms are unclear. The preovulatory LH surge induced by estrogen is preceded by a significant reduction in hypothalamic dynorphin and gamma-aminobutyric acid (GABA) release. To test the detailed roles of dynorphin and GABA in an LH surge blockade by progesterone, ovariectomized and 17β-estradiol capsule-implanted (OVX/E2) mice received simultaneous injections of estradiol benzoate (EB) and progesterone (P) or vehicle for 2 consecutive days. The LH level was monitored from 2:30 pm to 8:30 pm at 30-minute intervals. Progesterone coadministration resulted in the LH surge blockade. A continuous microinfusion of the dynorphin receptor antagonist nor-BNI or GABAA receptor antagonist bicuculline into the AVPV from 3:00 pm to 7:00 pm reversed the progesterone-mediated blockade of the LH surge in 7 of 9 and 6 of 10 mice, respectively. In addition, these LH surges started much earlier than the surge induced by estrogen alone. However, 5 of 7 progesterone-treated mice did not show LH surge secretion after microinfusion with the GABAB receptor antagonist CGP-35348. Additionally, peripheral administration of kisspeptin-54 promotes LH surge-like release in progesterone treated mice. These results demonstrated that the progesterone-mediated suppression of the LH surge is mediated by an increase in dynorphin and GABAA receptor signaling acting though kisspeptin neurons in the AVPV of the hypothalamus in female mice.
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Affiliation(s)
- Yali Liu
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
- Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine, Pudong New Area, Shanghai, China
| | - Xiaofeng Li
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
| | - Xi Shen
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
| | - Deyana Ivanova
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
| | - Geffen Lass
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
| | - Wen He
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Qiuju Chen
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Sha Yu
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Yun Wang
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Hui Long
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Li Wang
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Qifeng Lyu
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
| | - Yanping Kuang
- Department of Assisted Reproduction, Shanghai Ninth People’s Hospital Affiliated to Shanghai Jiaotong University School of Medicine, Huangpu District, Shanghai, China
- Correspondence: Kevin O’Byrne, PhD, 2.92W Hodgkin Building, Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, Guy’s Campus, King’s College London, London, SE1 1UL. E-mail: ; or Yanping Kuang, Department of Assisted Reproduction, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China. E-mail:
| | - Kevin T O’Byrne
- Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, King’s College London, Guy’s Campus, UK
- Correspondence: Kevin O’Byrne, PhD, 2.92W Hodgkin Building, Department of Women and Children’s Health, Faculty of Life Sciences and Medicine, Guy’s Campus, King’s College London, London, SE1 1UL. E-mail: ; or Yanping Kuang, Department of Assisted Reproduction, Shanghai Ninth People’s Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, People’s Republic of China. E-mail:
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25
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Wang Q, Zhang X, Leng H, Luan X, Guo F, Sun X, Gao S, Liu X, Qin H, Xu L. Zona incerta projection neurons and GABAergic and GLP-1 mechanisms in the nucleus accumbens are involved in the control of gastric function and food intake. Neuropeptides 2020; 80:102018. [PMID: 32000986 DOI: 10.1016/j.npep.2020.102018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 01/11/2020] [Accepted: 01/13/2020] [Indexed: 12/28/2022]
Abstract
OBJECTIVE Our aim was to explore the effect of γ-aminobutyric acid (GABA) signaling in the nucleus accumbens (NAc) on promoting gastric function and food intake through glucagon-like peptide 1 (GLP-1)-sensitive gastric distension (GD) neurons under the regulatory control of the zona incerta (ZI). METHODS GABA neuronal projections were traced using retrograde tracing following fluorescence immunohistochemistry. An extracellular electrophysiological recording method was used to observe the firing of neurons in the NAc. HPLC was used to quantify the GABA and glutamate levels in the NAc after electrical stimulation of the ZI. Gastric functions including gastric motility and secretion, as well as food intake, were measured after the administration of different concentrations of GABA in the NAc or electrical stimulation of the ZI. RESULTS Some of the GABA-positive neurons arising from the ZI projected to the NAc. Some GABA-A receptor (GABA-AR)-immunoreactive neurons in the NAc were also positive for GLP-1 receptor (GLP-1R) immunoreactivity. The firing of most GLP-1-sensitive GD neurons was decreased by GABA infusion in the NAc. Intra-NAc GABA administration also promoted gastric function and food intake. The responses induced by GABA were partially blocked by the GABA-AR antagonist bicuculline (BIC) and weakened by the GLP-1R antagonist exendin 9-39 (Ex9). Electrical stimulation of the ZI changed the firing patterns of most GLP-1-sensitive GD neurons in the NAc and promoted gastric function and food intake. Furthermore, these excitatory effects induced by electrical stimulation of the ZI were weakened by preadministration of BIC in the NAc. CONCLUSION Retrograde tracing and immunohistochemical staining showed a GABAergic pathway from the ZI to the NAc. GABAergic and GLP-1 mechanisms in the NAc are involved in the control of gastric function and food intake. In addition, the interaction (direct or indirect) between the ZI and these NAc mechanisms is involved in the control of gastric function and food intake.
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Affiliation(s)
- Qian Wang
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiaoqian Zhang
- Doctoral School of Biomedical Sciences, KU Leuven, B-300 Leuven, Belgium; Family Medicine Department, Qingdao United Family Hospital, Qingdao, Shandong 266001, China
| | - Hui Leng
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiao Luan
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Feifei Guo
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xiangrong Sun
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Shengli Gao
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Xuehuan Liu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Hao Qin
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China
| | - Luo Xu
- Department of Pathophysiology, School of Basic Medicine, Qingdao University, Qingdao, Shandong 266071, China.
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Saft C, Speckmann EJ. Antiepileptic effects of cobalt, manganese and magnesium on bicuculline-induced epileptiform activity in hippocampal neurons. Brain Res 2020; 1732:146684. [PMID: 32001242 DOI: 10.1016/j.brainres.2020.146684] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 01/22/2020] [Accepted: 01/25/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Calcium signaling is described as a relevant factor in synchronization of neurons and increased excitability in epileptogenesis. Aim of the present investigations was to test the antiepileptic effect of the classical inorganic calcium channel blockers cobalt (Co2+), manganese (Mn2+) and magnesium (Mg2+). METHODS Experiments were carried out on hippocampal slices of guinea pigs. Epileptiform field potentials (EFP) were elicited by adding bicuculline (10 µmol/l) to the artificial cerebrospinal fluid (CSF). Kalium was elevated from normal (4 mmol/l) to 8 mmol/l. Co2+ (CoCl2; 2, 1, 0.5 and 0.1 mmol/l), Mn2+ (MnCl2; 2, 1, 0.5 and 0.1 mmol/l) and Mg2+ (MgCl2; 8, 6, 5, 4 and 2 mmol/l) were added to the superfusate. RESULTS Concentrations of 2, 1 and 0.5 mmol/l Co2+, 2 and 1 mmol/l Mn2+ and 8 respectively 6 mmol/l Mg2+ were able to suppress EFP sufficient in a dose dependent manner. In concentrations of 0.1 mmol/l Co2+, 0.5 mmol/l and 0.1 mmol/l Mn2+ and 5 respectively 4 and 2 mmol/l Mg2+ suppression was incomplete. With washout of the inorganic calcium channel blockers the EFP reappeared. DISCUSSION All tree inorganic calcium channel blockers were able to suppress EFP in a dosage dependent and reversible manner. Weak reappearance of EFP after washout of Co2+ might be due to additional cytotoxic effects. The following mechanisms may contribute: i) blockade of voltage-activated calcium channels in the postsynaptic membrane, ii) changes in the activation of voltage-dependent sodium channels, iii) blockade of synaptic transmission.
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Affiliation(s)
- Carsten Saft
- Department of Neurology, St. Josef Hospital, Gudrunstraße 56, 44791 Bochum, Germany.
| | - Erwin-Josef Speckmann
- Institut für Physiology I, Westfälische Wilhelms Universität, Robert-Koch Str. 27a, 48149 Münster, Germany
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Dos Anjos-Garcia T, Coimbra NC. Anandamide in the anterior hypothalamus diminishes defensive responses elicited in mice threatened by Epicrates cenchria constrictor serpents. Acta Neurobiol Exp (Wars) 2020; 80:179-191. [PMID: 32602858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The purpose of this study was to investigate whether the panicolytic‑like effect of different doses of anandamide microinjected into the anterior hypothalamus (AH) follows the same pattern of a bell‑shaped dose‑response curve observed with the same dose treatment in dorsomedial and ventromedial hypothalamus. We investigated this assumption by administering the cannabinoid and vanilloid receptor agonist anandamide into the anterior hypothalamus of mice and exposing them to the real threatening situation by using our experimental model based on confrontations between rodents and wild snakes. Our findings showed a gradual decay of response, with a significant attenuation of the panic attack‑like responses with anandamide at the highest dose but no effect was found after anandamide at the lowest or intermediate doses. An immunohistochemical procedure showed a lower degree of TRPV1 receptor and moderate to higher degree of Cb1 receptors in anterior hypothalamus. In conclusion, the pattern of dose‑response curve of anandamide microinjected in the AH does not seem to be the same classical pattern compared with other hypothalamic nuclei.
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Affiliation(s)
- Tayllon Dos Anjos-Garcia
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP-USP), São Paulo, Brazil
- Ophidiarium LNN-FMRP-USP/INeC, Ribeirão Preto School of Medicine of the University of São Paulo (FMRP-USP), São Paulo, Brazil
| | - Norberto Cysne Coimbra
- Laboratory of Neuroanatomy and Neuropsychobiology, Department of Pharmacology, Ribeirão Preto Medical School of the University of São Paulo (FMRP‑USP), São Paulo, Brazil,
- Behavioural Neuroscience Institute (INeC), São Paulo, Brazil
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Abstract
The essential everyday task of making appropriate choices is a process controlled mainly by the basal ganglia. To this end, subjects need not only to find "good" objects in their environment but also to reject "bad" objects. To reveal this rejection mechanism, we created a sequential saccade choice task for monkeys and studied the role of the indirect pathway from the CDt (tail of the caudate nucleus) mediated by cvGPe (caudal-ventral globus pallidus externus). Neurons in cvGPe were typically inhibited by the appearance of bad objects; however, this inhibition was reduced on trials when the monkeys made undesired saccades to the bad objects. Moreover, disrupting the inhibitory influence of CDt on cvGPe by local injection of bicuculline (GABAA receptor antagonist) impaired the monkeys' ability to suppress saccades to bad objects. Thus, the indirect pathway mediates the rejection of bad choices, a crucial component of goal-directed behavior.
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Singh MB, White JA, McKimm EJ, Milosevic MM, Antic SD. Mechanisms of Spontaneous Electrical Activity in the Developing Cerebral Cortex-Mouse Subplate Zone. Cereb Cortex 2019; 29:3363-3379. [PMID: 30169554 PMCID: PMC7963116 DOI: 10.1093/cercor/bhy205] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 06/28/2018] [Accepted: 08/05/2018] [Indexed: 12/15/2022] Open
Abstract
Subplate (SP) neurons exhibit spontaneous plateau depolarizations mediated by connexin hemichannels. Postnatal (P1-P6) mice show identical voltage pattern and drug-sensitivity as observed in slices from human fetal cortex; indicating that the mouse is a useful model for studying the cellular physiology of the developing neocortex. In mouse SP neurons, spontaneous plateau depolarizations were insensitive to blockers of: synaptic transmission (glutamatergic, GABAergic, or glycinergic), pannexins (probenecid), or calcium channels (mibefradil, verapamil, diltiazem); while highly sensitive to blockers of gap junctions (octanol), hemichannels (La3+, lindane, Gd3+), or glial metabolism (DLFC). Application of La3+ (100 μM) does not exert its effect on electrical activity by blocking calcium channels. Intracellular application of Gd3+ determined that Gd3+-sensitive pores (putative connexin hemichannels) reside on the membrane of SP neurons. Immunostaining of cortical sections (P1-P6) detected connexins 26, and 45 in neurons, but not connexins 32 and 36. Vimentin-positive glial cells were detected in the SP zone suggesting a potential physiological interaction between SP neurons and radial glia. SP spontaneous activity was reduced by blocking glial metabolism with DFLC or by blocking purinergic receptors by PPADS. Connexin hemichannels and ATP release from vimentin-positive glial cells may underlie spontaneous plateau depolarizations in the developing mammalian cortex.
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Affiliation(s)
- Mandakini B Singh
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT, USA
| | - Jesse A White
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT, USA
| | - Eric J McKimm
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT, USA
| | - Milena M Milosevic
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT, USA
| | - Srdjan D Antic
- Institute for Systems Genomics, Stem Cell Institute, Department of Neuroscience, UConn Health, Farmington, CT, USA
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Reichard RA, Parsley KP, Subramanian S, Zahm DS. Dissociable effects of dopamine D1 and D2 receptors on compulsive ingestion and pivoting movements elicited by disinhibiting the ventral pallidum. Brain Struct Funct 2019; 224:1925-1932. [PMID: 31087183 PMCID: PMC6565492 DOI: 10.1007/s00429-019-01879-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/12/2019] [Indexed: 02/07/2023]
Abstract
Previous studies have shown that infusion of a GABAA receptor antagonist, such as bicuculline (bic), into the ventral (pallidum VP) of rats elicits vigorous ingestion in sated subjects and abnormal pivoting movements. Here, we assessed if the ingestive effects generalize to the lateral preoptic area (LPO) and tested both effects for modulation by dopamine receptor signaling. Groups of rats received injections of the dopamine D2 receptor antagonist, haloperidol (hal), the D1 antagonist, SCH-23390 (SCH), or vehicle (veh) followed by infusions of bic or veh into the VP or LPO. Ingestion effects were not observed following LPO bic infusions. Compulsive ingestion associated with VP activation was attenuated by hal, but not SCH. VP bic-elicited pivoting was attenuated by neither hal, nor SCH.
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Affiliation(s)
- Rhett A Reichard
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., Saint Louis, MO, 63104, USA.
- Department of Neuroscience, Medical University of South Carolina, 173 Ashley Avenue, Charleston, SC, 29425-8908, USA.
| | - Kenneth P Parsley
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., Saint Louis, MO, 63104, USA
| | - Suriya Subramanian
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., Saint Louis, MO, 63104, USA
| | - Daniel S Zahm
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd., Saint Louis, MO, 63104, USA.
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Zimmerman AL, Kovatsis EM, Pozsgai RY, Tasnim A, Zhang Q, Ginty DD. Distinct Modes of Presynaptic Inhibition of Cutaneous Afferents and Their Functions in Behavior. Neuron 2019; 102:420-434.e8. [PMID: 30826183 PMCID: PMC6472967 DOI: 10.1016/j.neuron.2019.02.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/17/2018] [Accepted: 01/31/2019] [Indexed: 01/10/2023]
Abstract
Presynaptic inhibition (PSI) of primary sensory neurons is implicated in controlling gain and acuity in sensory systems. Here, we define circuit mechanisms and functions of PSI of cutaneous somatosensory neuron inputs to the spinal cord. We observed that PSI can be evoked by different sensory neuron populations and mediated through at least two distinct dorsal horn circuit mechanisms. Low-threshold cutaneous afferents evoke a GABAA-receptor-dependent form of PSI that inhibits similar afferent subtypes, whereas small-diameter afferents predominantly evoke an NMDA-receptor-dependent form of PSI that inhibits large-diameter fibers. Behaviorally, loss of either GABAA receptors (GABAARs) or NMDA receptors (NMDARs) in primary afferents leads to tactile hypersensitivity across skin types, and loss of GABAARs, but not NMDARs, leads to impaired texture discrimination. Post-weaning age loss of either GABAARs or NMDARs in somatosensory neurons causes systemic behavioral abnormalities, revealing critical roles of two distinct modes of PSI of somatosensory afferents in adolescence and throughout adulthood.
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Affiliation(s)
- Amanda L Zimmerman
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Eleni M Kovatsis
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Riana Y Pozsgai
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Aniqa Tasnim
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Qiyu Zhang
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| | - David D Ginty
- Department of Neurobiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA.
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Haroush N, Marom S. Inhibition increases response variability and reduces stimulus discrimination in random networks of cortical neurons. Sci Rep 2019; 9:4969. [PMID: 30899035 PMCID: PMC6428807 DOI: 10.1038/s41598-019-41220-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 02/25/2019] [Indexed: 11/11/2022] Open
Abstract
Much of what is known about the contribution of inhibition to stimulus discrimination is due to extensively studied sensory systems, which are highly structured neural circuits. The effect of inhibition on stimulus representation in less structured networks is not as clear. Here we exercise a biosynthetic approach in order to study the impacts of inhibition on stimulus representation in non-specialized network anatomy. Combining pharmacological manipulation, multisite electrical stimulation and recording from ex-vivo randomly rewired networks of cortical neurons, we quantified the effects of inhibition on response variability and stimulus discrimination at the population and single unit levels. We find that blocking inhibition quenches variability of responses evoked by repeated stimuli and enhances discrimination between stimuli that invade the network from different spatial loci. Enhanced stimulus discrimination is reserved for representation schemes that are based on temporal relation between spikes emitted in groups of neurons. Our data indicate that - under intact inhibition - the response to a given stimulus is a noisy version of the response evoked in the absence of inhibition. Spatial analysis suggests that the dispersion effect of inhibition is due to disruption of an otherwise coherent, wave-like propagation of activity.
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Affiliation(s)
- Netta Haroush
- Network Biology Research Laboratory, Faculty of Electrical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel.
- Department of Physiology, Biophysics and Systems Biology, Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 32000, Israel.
| | - Shimon Marom
- Network Biology Research Laboratory, Faculty of Electrical Engineering, Technion - Israel Institute of Technology, Haifa, 32000, Israel
- Department of Physiology, Biophysics and Systems Biology, Faculty of Medicine, Technion - Israel Institute of Technology, Haifa, 32000, Israel
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Davoudi M, Azizi H, Mirnajafi-Zadeh J, Semnanian S. Decrease of inhibitory synaptic currents of locus coeruleus neurons via orexin type 1 receptors in the context of naloxone-induced morphine withdrawal. J Physiol Sci 2019; 69:281-293. [PMID: 30406600 PMCID: PMC10717061 DOI: 10.1007/s12576-018-0645-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/25/2018] [Indexed: 10/27/2022]
Abstract
Acute opioid withdrawal syndrome is a series of neurological symptoms caused by the abrupt cessation of the chronic administration of opioids such as morphine. The locus coeruleus (LC) in the brain stem receives a dense projection of orexinergic fibers from the hypothalamus and is a candidate site for the expression of the somatic aspects of morphine withdrawal. Previous studies have shown that orexin-A contributes to the behavioral symptoms of naloxone-induced morphine withdrawal, partly by reducing the activity of GABAergic neurons, suggesting that orexin-A may negatively modulate fast GABAergic neurotransmission during morphine withdrawal. We used whole-cell patch-clamp recordings of LC neurons in brainstem slices to investigate the effect of orexin-A on bicuculline-sensitive GABAergic inhibitory postsynaptic currents (IPSCs) during naloxone-induced morphine withdrawal. Male Wistar rats (P14-P21) were given morphine (20 mg/kg, i.p.) daily for seven consecutive days to create dependency on the drug. The application of naloxone (1 µM) to brain slices of morphine-treated rats reduced the amplitude of evoked IPSCs (eIPSCs) as well as spontaneous IPSCs (sIPSCs) frequency but did not change sIPSCs amplitude. Orexin-A (100 nM) significantly enhanced the suppressive effect of naloxone on eIPSCs amplitude and sIPSCs frequency but had no effect on the presence of the orexin type 1 receptor (OX1R) antagonist, SB-334867. Orexin-A alone had no significant effect on eIPSCs and sIPSCs in the absence of naloxone. In summary, our results show that orexin-A, via OX1R, potentiates the suppressive effect of naloxone on GABAergic IPSCs of LC neurons in morphine-treated rats. We conclude that orexins may have a critical role in regulating GABAergic neurotransmission to LC neurons during naloxone-induced morphine withdrawal.
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Affiliation(s)
- Mahnaz Davoudi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Hossein Azizi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saeed Semnanian
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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Rahbar I, Abbasnejad M, Haghani J, Raoof M, Kooshki R, Esmaeili-Mahani S. The effect of central administration of alpha-pinene on capsaicin-induced dental pulp nociception. Int Endod J 2019; 52:307-317. [PMID: 30152861 DOI: 10.1111/iej.13006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 08/23/2018] [Indexed: 01/17/2023]
Abstract
AIM To assess the effects of central administration of α-pinene alone and in combination with either bicuculline or naloxone, as GABAA and μ-opioid receptor antagonists, respectively, on capsaicin-induced dental pulp stimulation in rats. METHODOLOGY Forty-eight adult male Wistar rats aged 2 months (230-270 g) were cannulated via their lateral ventricles for the central administration of the drugs. α-Pinene was injected at 0.1, 0.2 and 0.4 μmol L-1 . Then, dental pulp stimulation was induced by intradental application of capsaicin solution (100 μg), and nociceptive scores were recorded for up to 40 min. For investigation of the anti-inflammatory effects of α-pinene, expression of COX-2 in the subnucleolus caudalis (Vc) of rats was determined using immunofluorescence staining. Nonparametric repeated measure Friedman and Kruskal-Wallis tests as well as parametric one-way analysis of variance were used for the statistical analysis. RESULTS α-Pinene at 0.2 and 0.4 μmol L-1 was able to decrease capsaicin-induced nociception. Moreover, there was a significant increase in the expression of COX-2-positive cells in the Vc of capsaicin-treated rats (P < 0.01). This effect was prohibited by α-pinene (0.4 μmol L-1 ). Co-administration of bicuculline (1 μg per rat) or naloxone (6 μg per rat) with α-pinene (0.4 μmol L-1 ), however, prevented the inhibitory effects of α-pinene on both capsaicin-induced pulp nociception and COX-2 over-expression. CONCLUSIONS Pinene exhibited significant curable effects on capsaicin-induced pulpal nociception and inflammation mainly via pharmacological interfacing with GABAA and μ-opioid receptors.
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Affiliation(s)
- I Rahbar
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
| | - M Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
| | - J Haghani
- Endodontology Research Center, Kerman University of Medical Sciences, Iran
| | - M Raoof
- Laboratory of Molecular Neuroscience, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - R Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
| | - S Esmaeili-Mahani
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
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Green MV, Thayer SA. HIV gp120 upregulates tonic inhibition through α5-containing GABA ARs. Neuropharmacology 2019; 149:161-168. [PMID: 30797029 DOI: 10.1016/j.neuropharm.2019.02.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/30/2018] [Accepted: 02/17/2019] [Indexed: 12/17/2022]
Abstract
HIV-Associated Neurocognitive disorder (HAND) affects nearly half of infected patients. The HIV envelope protein gp120 is shed by infected cells and is a potent neurotoxin in vitro that reproduces many aspects of HAND when expressed in vivo. Here, we show that HIV gp120 increases the amplitude of a tonic current mediated by γ-aminobutyric acid type-A receptors (GABAARs). Treating rat hippocampal cultures with 600 pM gp120IIIB for 4 h increased a tonic bicuculline-sensitive current, which remained elevated for 24 h. The increased current resulted from upregulation of extrasynaptic α5-containing GABAARs, as indicated by inhibition with the selective inverse agonist basmisanil. Treatment with gp120 increased α5-GABAAR immunoreactivity on the cell surface without new protein synthesis. The increase in tonic inhibition was prevented by a C-X-C chemokine receptor type 4 (CXCR4) antagonist or elimination of microglia from the culture. Treatment with interleukin-1β (IL-1β) increased the tonic current and an IL-1 receptor antagonist blocked the gp120-evoked response. Pharmacological or genetic inhibition of p38 mitogen-activated protein kinase (MAPK) prevented the gp120-evoked increase in tonic current and direct activation of a mutant form of p38 MAPK expressed in neurons increased the current. Collectively, these data show that gp120 activates CXCR4 to stimulate microglia to release IL-1β. Subsequent stimulation of IL-1 receptors activates p38 MAPK in neurons leading to the upregulation of α5-containing GABAARs. Increased tonic inhibition impairs neuroplasticity and inhibition of α5-containing GABAARs improves cognitive function in disease models. Thus, gp120-induced upregulation of α5-containing GABAARs presents a novel therapeutic target for HAND.
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Affiliation(s)
- Matthew V Green
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA
| | - Stanley A Thayer
- Graduate Program in Neuroscience, University of Minnesota Medical School, Minneapolis, MN, 55455, USA; Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, 55455, USA.
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Masiulis S, Desai R, Uchański T, Serna Martin I, Laverty D, Karia D, Malinauskas T, Zivanov J, Pardon E, Kotecha A, Steyaert J, Miller KW, Aricescu AR. GABA A receptor signalling mechanisms revealed by structural pharmacology. Nature 2019; 565:454-459. [PMID: 30602790 PMCID: PMC6370056 DOI: 10.1038/s41586-018-0832-5] [Citation(s) in RCA: 318] [Impact Index Per Article: 63.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/23/2018] [Indexed: 01/02/2023]
Abstract
Type-A γ-aminobutyric (GABAA) receptors are ligand-gated chloride channels with a very rich pharmacology. Some of their modulators, including benzodiazepines and general anaesthetics, are among the most successful drugs in clinical use and are common substances of abuse. Without reliable structural data, the mechanistic basis for the pharmacological modulation of GABAA receptors remains largely unknown. Here we report several high-resolution cryo-electron microscopy structures in which the full-length human α1β3γ2L GABAA receptor in lipid nanodiscs is bound to the channel-blocker picrotoxin, the competitive antagonist bicuculline, the agonist GABA (γ-aminobutyric acid), and the classical benzodiazepines alprazolam and diazepam. We describe the binding modes and mechanistic effects of these ligands, the closed and desensitized states of the GABAA receptor gating cycle, and the basis for allosteric coupling between the extracellular, agonist-binding region and the transmembrane, pore-forming region. This work provides a structural framework in which to integrate previous physiology and pharmacology research and a rational basis for the development of GABAA receptor modulators.
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Affiliation(s)
- Simonas Masiulis
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
| | - Rooma Desai
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tomasz Uchański
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Itziar Serna Martin
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Duncan Laverty
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Dimple Karia
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Jasenko Zivanov
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Abhay Kotecha
- Materials and Structural Analysis, Thermo Fisher Scientific, Eindhoven, The Netherlands
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Keith W Miller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - A Radu Aricescu
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
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Constantin S, Wray S. Nociceptin/Orphanin-FQ Inhibits Gonadotropin-Releasing Hormone Neurons via G-Protein-Gated Inwardly Rectifying Potassium Channels. eNeuro 2018; 5:ENEURO.0161-18.2018. [PMID: 30627649 PMCID: PMC6325553 DOI: 10.1523/eneuro.0161-18.2018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 12/03/2018] [Accepted: 12/03/2018] [Indexed: 12/18/2022] Open
Abstract
The pulsatile release of gonadotropin-releasing hormone (GnRH) is a key feature of the hypothalamic-pituitary-gonadal axis. Kisspeptin neurons in the arcuate nucleus (ARC) trigger GnRH neuronal activity, but how GnRH neurons return to baseline electrical activity is unknown. Nociceptin/orphanin-FQ (OFQ) is an inhibitory neuromodulator. ARC proopiomelanocortin (POMC) neurons, known to receive inputs from ARC kisspeptin neurons, contact GnRH neurons and coexpress OFQ in the rat. In the present study, the effect of OFQ(1-13) on GnRH neurons was determined in the mouse. We identified transcripts for the OFQ receptor [opioid receptor like 1 (ORL1)] in GnRH neurons, and, using two-model systems (explants and slices), we found that OFQ exerted a potent inhibition on GnRH neurons, with or without excitatory inputs. We confirmed that the inhibition was mediated by ORL1 via Gi/o-protein coupling. The inhibition, occurring independently of levels of intracellular cyclic adenosine monophosphate, was sensitive to inwardly rectifying potassium channels. The only specific blocker of Gi/o-protein-coupled inwardly rectifying potassium (GIRK) channels, tertiapin-Q (TPNQ), was ineffective in the inhibition of OFQ. Two GIRK activators, one sharing the binding site of TPNQ and one active only on GIRK1-containing GIRK channels, failed to trigger an inhibition. In contrast, protein kinase C phosphorylation activation, known to inhibit GIRK2-mediated currents, prevented the OFQ inhibition. These results indicate a specific combination of GIRK subunits, GIRK2/3 in GnRH neurons. In vivo, double-labeled OFQ/POMC fibers were found in the vicinity of GnRH neurons, and OFQ fibers apposed GnRH neurons. Together, this study brings to light a potent neuromodulator of GnRH neurons.
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Affiliation(s)
- Stephanie Constantin
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
| | - Susan Wray
- Cellular and Developmental Neurobiology Section, National Institute of Neurological Disorders and Stroke/National Institutes of Health, Bethesda, Maryland 20892-3703
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Abstract
The role of GABAergic inhibition in the regulation of activity of the parafacial respiratory group was studied on narcotized mature rats. Microinjections of GABAA agonist muscimol into the parafacial respiratory group inhibited external respiration and bioelectrical activity of the diaphragmatic muscle resulting in diminished tidal volume and decreased respiration rate accompanied by prolonged inspiration, expiration, and intervals between the inspiratory bursts in the phrenic electromyogram. In contrast, microinjections of GABAA antagonist bicuculline into this group stimulated respiration and markedly increased its volumetric parameters. In addition, blockade of GABAA receptors affected the expiratory phase and interburst intervals in the phrenic electromyogram, but produced no effect on respiration rate. These findings attested to contribution of GABAA-mediated inhibition into the performance of parafacial respiratory group. The study revealed different roles of GABAA receptors in modulation of the mechanisms of respiration rate control in mature rats and formation of inspiratory motor outputs originating from the parafacial respiratory group.
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Affiliation(s)
- O A Vedyasova
- Department of Human and Animal Physiology, S. P. Korolev Samara National Research University, Samara, Russia.
| | - T E Kovaleva
- Department of Human and Animal Physiology, S. P. Korolev Samara National Research University, Samara, Russia
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Luo H, Wood K, Shi FD, Gao F, Chang Y. Suramin is a novel competitive antagonist selective to α1β2γ2 GABA A over ρ1 GABA C receptors. Neuropharmacology 2018; 141:148-157. [PMID: 30172846 DOI: 10.1016/j.neuropharm.2018.08.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 08/12/2018] [Accepted: 08/26/2018] [Indexed: 02/05/2023]
Abstract
GABAA and GABAC receptors are both GABA-gated chloride channels with distinct pharmacological properties, mainly in their sensitivity to bicuculline and gabazine. In this study, we found that suramin, a purinergic receptor antagonist, is a novel competitive antagonist selective to GABAA over GABAC receptors. Specifically, suramin antagonized the GABA-induced current and the spontaneous opening current of the wild type α1β2γ2 GABAA receptor with high-level expression in Xenopus oocytes. The antagonism was concentration dependent with an IC50 that varied depending on the concentration of GABA, and with the lowest IC50 of 0.43 μM when antagonizing the spontaneous current. Thus, its potency is slightly higher than bicuculline on the same GABAA receptor. Suramin also antagonized the mouse native brain GABA receptors micro-transplanted into the Xenopus oocytes with its potency depending on the GABA concentration. In addition, in the presence of two fixed concentrations of suramin, the GABA concentration response of the receptor was shifted to the right without reduction of the maximum current. Thus, our results are consistent with that suramin is a competitive antagonist for the α1β2γ2 GABAA receptor. Interestingly, the rank order of maximum allosteric inhibition (efficacy) of spontaneous current of the GABAA receptor by three competitive antagonists was suramin > bicuculline > gabazine, similar to the rank order of their molecular weight. In contrast, similar to bicuculline, suramin has much lower potency in antagonizing the GABA-induced current of the ρ1 GABAC receptor. In conclusion, we have identified a novel GABAA receptor competitive antagonist, which is selective to the α1β2γ2 over ρ1 GABA receptors.
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Affiliation(s)
- Hui Luo
- Department of Pharmacology, Shantou University Medical College, Shantou, Guangdong, China; Division of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Kristofer Wood
- Division of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Fu-Dong Shi
- Division of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA
| | - Fenfei Gao
- Department of Pharmacology, Shantou University Medical College, Shantou, Guangdong, China
| | - Yongchang Chang
- Division of Neurobiology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ, USA.
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Shi Y, Chen Y, Wang Y. Kir2.1 Channel Regulation of Glycinergic Transmission Selectively Contributes to Dynamic Mechanical Allodynia in a Mouse Model of Spared Nerve Injury. Neurosci Bull 2018; 35:301-314. [PMID: 30203408 DOI: 10.1007/s12264-018-0285-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 07/20/2018] [Indexed: 11/25/2022] Open
Abstract
Neuropathic pain is a chronic debilitating symptom characterized by spontaneous pain and mechanical allodynia. It occurs in distinct forms, including brush-evoked dynamic and filament-evoked punctate mechanical allodynia. Potassium channel 2.1 (Kir2.1), which exhibits strong inward rectification, is and regulates the activity of lamina I projection neurons. However, the relationship between Kir2.1 channels and mechanical allodynia is still unclear. In this study, we first found that pretreatment with ML133, a selective Kir2.1 inhibitor, by intrathecal administration, preferentially inhibited dynamic, but not punctate, allodynia in mice with spared nerve injury (SNI). Intrathecal injection of low doses of strychnine, a glycine receptor inhibitor, selectively induced dynamic, but not punctate allodynia, not only in naïve but also in ML133-pretreated mice. In contrast, bicuculline, a GABAA receptor antagonist, induced only punctate, but not dynamic, allodynia. These results indicated the involvement of glycinergic transmission in the development of dynamic allodynia. We further found that SNI significantly suppressed the frequency, but not the amplitude, of the glycinergic spontaneous inhibitory postsynaptic currents (gly-sIPSCs) in neurons on the lamina II-III border of the spinal dorsal horn, and pretreatment with ML133 prevented the SNI-induced gly-sIPSC reduction. Furthermore, 5 days after SNI, ML133, either by intrathecal administration or acute bath perfusion, and strychnine sensitively reversed the SNI-induced dynamic, but not punctate, allodynia and the gly-sIPSC reduction in lamina IIi neurons, respectively. In conclusion, our results suggest that blockade of Kir2.1 channels in the spinal dorsal horn selectively inhibits dynamic, but not punctate, mechanical allodynia by enhancing glycinergic inhibitory transmission.
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Affiliation(s)
- Yiqian Shi
- Department of Neurology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China
| | - Yangyang Chen
- Department of Neurology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, 200032, China.
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Chang YY, Gong XW, Gong HQ, Liang PJ, Zhang PM, Lu QC. GABA A Receptor Activity Suppresses the Transition from Inter-ictal to Ictal Epileptiform Discharges in Juvenile Mouse Hippocampus. Neurosci Bull 2018; 34:1007-1016. [PMID: 30128691 DOI: 10.1007/s12264-018-0273-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 05/31/2018] [Indexed: 12/12/2022] Open
Abstract
Exploring the transition from inter-ictal to ictal epileptiform discharges (IDs) and how GABAA receptor-mediated action affects the onset of IDs will enrich our understanding of epileptogenesis and epilepsy treatment. We used Mg2+-free artificial cerebrospinal fluid (ACSF) to induce epileptiform discharges in juvenile mouse hippocampal slices and used a micro-electrode array to record the discharges. After the slices were exposed to Mg2+-free ACSF for 10 min-20 min, synchronous recurrent seizure-like events were recorded across the slices, and each event evolved from inter-ictal epileptiform discharges (IIDs) to pre-ictal epileptiform discharges (PIDs), and then to IDs. During the transition from IIDs to PIDs, the duration of discharges increased and the inter-discharge interval decreased. After adding 3 μmol/L of the GABAA receptor agonist muscimol, PIDs and IDs disappeared, and IIDs remained. Further, the application of 10 μmol/L muscimol abolished all the epileptiform discharges. When the GABAA receptor antagonist bicuculline was applied at 10 μmol/L, IIDs and PIDs disappeared, and IDs remained at decreased intervals. These results indicated that there are dynamic changes in the hippocampal network preceding the onset of IDs, and GABAA receptor activity suppresses the transition from IIDs to IDs in juvenile mouse hippocampus.
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Affiliation(s)
- Yan-Yan Chang
- Department of Neurology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China
| | - Xin-Wei Gong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hai-Qing Gong
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Pei-Ji Liang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Pu-Ming Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Qin-Chi Lu
- Department of Neurology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, 200127, China.
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Huang YJ, Grau JW. Ionic plasticity and pain: The loss of descending serotonergic fibers after spinal cord injury transforms how GABA affects pain. Exp Neurol 2018; 306:105-116. [PMID: 29729247 PMCID: PMC5994379 DOI: 10.1016/j.expneurol.2018.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/24/2018] [Accepted: 05/01/2018] [Indexed: 12/14/2022]
Abstract
Activation of pain (nociceptive) fibers can sensitize neural circuits within the spinal cord, inducing an increase in excitability (central sensitization) that can foster chronic pain. The development of spinally-mediated central sensitization is regulated by descending fibers and GABAergic interneurons. In adult animals, the co-transporter KCC2 maintains a low intracellular concentration of the anion Cl-. As a result, when the GABA-A receptor is engaged, Cl- flows in the neuron which has a hyperpolarizing (inhibitory) effect. Spinal cord injury (SCI) can down-regulate KCC2 and reverse the flow of Cl-. Under these conditions, engaging the GABA-A receptor can have a depolarizing (excitatory) effect that fosters the development of nociceptive sensitization. The present paper explores how SCI alters GABA function and provides evidence that the loss of descending fibers alters pain transmission to the brain. Prior work has shown that, after SCI, administration of a GABA-A antagonist blocks the development of capsaicin-induced nociceptive sensitization, implying that GABA release plays an essential role. This excitatory effect is linked to serotonergic (5HT) fibers that descend through the dorsolateral funiculus (DLF) and impact spinal function via the 5HT-1A receptor. Supporting this, blocking the 5HT-1A receptor, or lesioning the DLF, emulated the effect of SCI. Conversely, spinal application of a 5HT-1A agonist up-regulated KCC2 and reversed the effect of bicuculline treatment. Finally, lesioning the DLF reversed how a GABA-A antagonist affects a capsaicin-induced aversion in a place conditioning task; in sham operated animals, bicuculline enhanced aversion whereas in DLF-lesioned rats biciculline had an antinociceptive effect.
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Affiliation(s)
- Yung-Jen Huang
- Behavioral and Cellular Neuroscience, Department of Psychology, Texas A&M University, College Station, TX 77843, USA.
| | - James W Grau
- Behavioral and Cellular Neuroscience, Department of Psychology, Texas A&M University, College Station, TX 77843, USA
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43
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Subramanian S, Reichard RA, Stevenson HS, Schwartz ZM, Parsley KP, Zahm DS. Lateral preoptic and ventral pallidal roles in locomotion and other movements. Brain Struct Funct 2018; 223:2907-2924. [PMID: 29700637 PMCID: PMC5997555 DOI: 10.1007/s00429-018-1669-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/19/2018] [Indexed: 12/31/2022]
Abstract
The lateral preoptic area (LPO) and ventral pallidum (VP) are structurally and functionally distinct territories in the subcommissural basal forebrain. It was recently shown that unilateral infusion of the GABAA receptor antagonist, bicuculline, into the LPO strongly invigorates exploratory locomotion, whereas bicuculline infused unilaterally into the VP has a negligible locomotor effect, but when infused bilaterally, produces vigorous, abnormal pivoting and gnawing movements and compulsive ingestion. This study was done to further characterize these responses. We observed that bilateral LPO infusions of bicuculline activate exploratory locomotion only slightly more potently than unilateral infusions and that unilateral and bilateral LPO injections of the GABAA receptor agonist muscimol potently suppress basal locomotion, but only modestly inhibit locomotion invigorated by amphetamine. In contrast, unilateral infusions of muscimol into the VP affect basal and amphetamine-elicited locomotion negligibly, but bilateral VP muscimol infusions profoundly suppress both. Locomotor activation elicited from the LPO by bicuculline was inhibited modestly and profoundly by blockade of dopamine D2 and D1 receptors, respectively, but was not entirely abolished even under combined blockade of dopamine D1 and D2 receptors. That is, infusing the LPO with bic caused instances of near normal, even if sporadic, invigoration of locomotion in the presence of saturating dopamine receptor blockade, indicating that LPO can stimulate locomotion in the absence of dopamine signaling. Pivoting following bilateral VP bicuculline infusions was unaffected by dopamine D2 receptor blockade, but was completely suppressed by D1 receptor blockade. The present results are discussed in a context of neuroanatomical and functional organization underlying exploratory locomotion and adaptive movements.
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Affiliation(s)
- Suriya Subramanian
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Rhett A Reichard
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Hunter S Stevenson
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Zachary M Schwartz
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Kenneth P Parsley
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA
| | - Daniel S Zahm
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, Saint Louis, MO, 63104, USA.
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44
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Acerbo MJ, Lazareva OF. Pharmacological manipulation of GABA activity in nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS) impairs figure-ground discrimination in pigeons: Running head: SP/IPS in figure-ground segregation. Behav Brain Res 2018; 344:1-8. [PMID: 29408282 DOI: 10.1016/j.bbr.2018.01.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 01/09/2018] [Accepted: 01/30/2018] [Indexed: 11/18/2022]
Abstract
Figure-ground segregation is a fundamental visual ability that allows an organism to separate an object from its background. Our earlier research has shown that nucleus rotundus (Rt), a thalamic nucleus processing visual information in pigeons, together with its inhibitory complex, nucleus subpretectalis/interstitio-pretecto-subpretectalis (SP/IPS), are critically involved in figure-ground discrimination (Acerbo et al., 2012; Scully et al., 2014). Here, we further investigated the role of SP/IPS by conducting bilateral microinjections of GABAergic receptor antagonist and agonists (bicuculline and muscimol, respectively) and non-NMDA glutamate receptor antagonist (CNQX) after the pigeons mastered figure-ground discrimination task. We used two doses of each drug (bicuculline: 0.1 mM and 0.05 mM; muscimol: 4.4 mM and 8.8 mM; CNQX: 2.15 mM and 4.6 mM) in a within-subject design, and alternated drug injections with baseline (ACSF). The order of injections was randomized across birds to reduce potential carryover effects. We found that a low dose of bicuculline produced a decrement on figure trials but not on background trials, whereas a high dose impaired performance on background trials but not on figure trials. Muscimol produced an equivalent, dose-dependent impairment on both types of trials. Finally, CNQX had no consistent effect at either dose. Together, these results further confirm our earlier hypothesis that inhibitory projections from SP to Rt modulate figure-ground discrimination, and suggest that the Rt and the SP/IPS provide a plausible substrate that could perform figure-ground segregation in avian brain.
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Abstract
Both serotonin (5-HT) and stress exert changes in cortical inhibitory tone to shape the activity of cortical networks. Because astrocytes are also known to affect inhibition through established purinergic pathways, we assessed the role of GABA and purinergic pathways with respect to the effects of rapid corticosterone (CORT) and 5-HT on cortical inhibition. We used a paired-pulse paradigm (P1 and P2) in acutely isolated mouse brain slices to evaluate changes in cortical evoked inhibition. Normally, 5-HT decreases the amplitude of the first pulse P1, whereas it increases the amplitude of P2 (increasing frequency transmission). Interestingly, it was observed that CORT application decreased P1 and increased P2 similar to that of 5-HT application. Given that CORT and 5-HT are known to modulate inhibition, we applied the GABAA antagonist bicuculline in the presence of both and found that the increase in P2 and the P2/P1 was lost, providing evidence for a common mechanism involving GABAA receptor signalling. Additional occlusion experiments (ie, 5-HT in presence of CORT and CORT in presence of 5-HT) provide further support for a common mechanism. Because both 5-HT and CORT blocked the increase in P2 and P2/P1 with respect to the other, we suggest 5-HT/CORT already utilise the shared mechanism to affect cortical inhibition. Using low concentrations of the GAPDH inhibitor iodoacetate, as commonly used to selectively disrupt astrocyte metabolism, we found that the increase in P2 and P2/P1 was similarly blocked in response to both CORT and 5-HT. Because astrocyte signalling depends in large part on purinergic pathways, the purinergic contribution was assessed using Ab129 (P2Y antagonist) and SCH 58261 (A2A antagonist). Once again, P2Y and A2A receptor blockade similarly disrupted 5-HT- or CORT-mediated increases in P2 and P2/P1. Taken together, these results support the common involvement of GABAergic and purinergic pathways in the effects of CORT and 5-HT that may also involve astrocytes.
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Affiliation(s)
- C A Wotton
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - E F Quon
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - A C Palmer
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - L K Bekar
- Department of Pharmacology, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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46
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Gómez CA, Sutin J, Wu W, Fu B, Uhlirova H, Devor A, Boas DA, Sakadžić S, Yaseen MA. Phasor analysis of NADH FLIM identifies pharmacological disruptions to mitochondrial metabolic processes in the rodent cerebral cortex. PLoS One 2018; 13:e0194578. [PMID: 29561904 PMCID: PMC5862490 DOI: 10.1371/journal.pone.0194578] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 03/06/2018] [Indexed: 01/20/2023] Open
Abstract
Investigating cerebral metabolism in vivo at a microscopic level is essential for understanding brain function and its pathological alterations. The intricate signaling and metabolic dynamics between neurons, glia, and microvasculature requires much more detailed understanding to better comprehend the mechanisms governing brain function and its disease-related changes. We recently demonstrated that pharmacologically-induced alterations to different steps of cerebral metabolism can be distinguished utilizing 2-photon fluorescence lifetime imaging of endogenous reduced nicotinamide adenine dinucleotide (NADH) fluorescence in vivo. Here, we evaluate the ability of the phasor analysis method to identify these pharmacological metabolic alterations and compare the method's performance with more conventional nonlinear curve-fitting analysis. Visualization of phasor data, both at the fundamental laser repetition frequency and its second harmonic, enables resolution of pharmacologically-induced alterations to mitochondrial metabolic processes from baseline cerebral metabolism. Compared to our previous classification models based on nonlinear curve-fitting, phasor-based models required fewer parameters and yielded comparable or improved classification accuracy. Fluorescence lifetime imaging of NADH and phasor analysis shows utility for detecting metabolic alterations and will lead to a deeper understanding of cerebral energetics and its pathological changes.
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Affiliation(s)
- Carlos A. Gómez
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Jason Sutin
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Weicheng Wu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Buyin Fu
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Hana Uhlirova
- Department of Neurosciences and Radiology, UC San Diego, La Jolla, CA, United States of America
- Central European Institute of Technology, Brno University of Technology, Brno, Czech Republic
| | - Anna Devor
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
- Department of Neurosciences and Radiology, UC San Diego, La Jolla, CA, United States of America
| | - David A. Boas
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
| | - Mohammad A. Yaseen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States of America
- * E-mail:
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47
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Abstract
Cortical sensory maps are remodeled during early life to adapt to the surrounding environment. Both sensory and contextual signals are important for induction of this plasticity, but how these signals converge to sculpt developing thalamocortical circuits remains largely unknown. Here we show that layer 1 (L1) of primary auditory cortex (A1) is a key hub where neuromodulatory and topographically organized thalamic inputs meet to tune the cortical layers below. Inhibitory interneurons in L1 send narrowly descending projections to differentially modulate thalamic drive to pyramidal and parvalbumin-expressing (PV) cells in L4, creating brief windows of intracolumnar activation. Silencing of L1 (but not VIP-expressing) cells abolishes map plasticity during the tonotopic critical period. Developmental transitions in nicotinic acetylcholine receptor (nAChR) sensitivity in these cells caused by Lynx1 protein can be overridden to extend critical-period closure. Notably, thalamocortical maps in L1 are themselves stable, and serve as a scaffold for cortical plasticity throughout life.
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Affiliation(s)
- Anne E Takesian
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Center for Brain Science, Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Luke J Bogart
- Center for Brain Science, Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Jeff W Lichtman
- Center for Brain Science, Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Takao K Hensch
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.
- Center for Brain Science, Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA, USA.
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Magagna-Poveda A, Moretto JN, Scharfman HE. Increased gyrification and aberrant adult neurogenesis of the dentate gyrus in adult rats. Brain Struct Funct 2017; 222:4219-4237. [PMID: 28656372 PMCID: PMC5909844 DOI: 10.1007/s00429-017-1457-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Accepted: 06/06/2017] [Indexed: 02/08/2023]
Abstract
A remarkable example of maladaptive plasticity is the development of epilepsy after a brain insult or injury to a normal animal or human. A structure that is considered central to the development of this type of epilepsy is the dentate gyrus (DG), because it is normally a relatively inhibited structure and its quiescence is thought to reduce hippocampal seizure activity. This characteristic of the DG is also considered to be important for normal hippocampal-dependent cognitive functions. It has been suggested that the brain insults which cause epilepsy do so because they cause the DG to be more easily activated. One type of brain insult that is commonly used is induction of severe seizures (status epilepticus; SE) by systemic injection of a convulsant drug. Here we describe an alteration in the DG after this type of experimental SE that may contribute to chronic seizures that has not been described before: large folds or gyri that develop in the DG by 1 month after SE. Large gyri appeared to increase network excitability because epileptiform discharges recorded in hippocampal slices after SE were longer in duration when recorded inside gyri relative to locations outside gyri. Large gyri may also increase excitability because immature adult-born neurons accumulated at the base of gyri with time after SE, and previous studies have suggested that abnormalities in adult-born DG neurons promote seizures after SE. In summary, large gyri after SE are a common finding in adult rats, show increased excitability, and are associated with the development of an abnormal spatial distribution of adult-born neurons. Together these alterations may contribute to chronic seizures and associated cognitive comorbidities after SE.
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Affiliation(s)
- Alejandra Magagna-Poveda
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Jillian N Moretto
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA
| | - Helen E Scharfman
- The Nathan Kline Institute of Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd. Bldg. 35, Orangeburg, NY, 10962, USA.
- Department of Child and Adolescent Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Physiology and Neuroscience, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
- Department of Psychiatry, New York University Langone Medical Center, One Park Ave., New York, NY, 10016, USA.
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Garabadu D, Krishnamurthy S. Metformin attenuates hepatic insulin resistance in type-2 diabetic rats through PI3K/Akt/GLUT-4 signalling independent to bicuculline-sensitive GABA A receptor stimulation. Pharm Biol 2017; 55:722-728. [PMID: 28142314 PMCID: PMC6130720 DOI: 10.1080/13880209.2016.1268635] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 08/26/2016] [Accepted: 11/30/2016] [Indexed: 06/06/2023]
Abstract
CONTEXT Metformin attenuates type-2 diabetes mellitus (T2DM)-induced hepatic dysfunction and altered PI3K/Akt/GLUT-4 signalling in experimental studies. However, its effect on bicuculline-sensitive gamma amino butyric acid (GABA)-A receptor (GABAAR)-mediated calcium-dependent PI3K/Akt/GLUT-4 signalling in liver challenged to T2DM has not been established. OBJECTIVE The effectiveness of metformin on bicuculline-sensitive GABAAR-mediated hepatic insulin signalling was carried out in presence or absence of bicuculline (2.0 mg/kg, i.p.) in experimental T2DM rats. MATERIALS AND METHODS The whole experimental design was divided into three independent sets of experiments. Each set comprised seven groups of six male rats each. T2DM was induced in the animals by administering streptozotocin (45 mg/kg, i.p.) and nicotinamide (110 mg/kg, i.p.) at a time lag of 15 min except control group rats in three experiments. Metformin and/or bicuculline or wortmannin were administered once daily for one week from seventh day of streptozotocin injection in all the experimental sets. RESULTS Metformin attenuated T2DM-induced hyperglycaemia in glucose (40%) and insulin (50%) tolerance tests in rats. Metformin also attenuated T2DM-induced hyperglycaemia (40%), hyperinsulinaemia (30%), insulin resistance (50%) and β-cell dysfunction (300%) in the animals. Metformin did not attenuate T2DM-induced decrease in rat hepatic intracellular calcium. Further, metformin mitigated T2DM-induced decrease in hepatic phosphorylated Akt and GLUT-4 translocation in the animals. The anti-diabetic activity of metformin was abolished by wortmannin but not with bicuculline co-administration in T2DM animals. DISCUSSION AND CONCLUSION These results suggest that metformin ameliorated T2DM-induced hepatic insulin resistance through bicuculline-sensitive GABAA receptor-independent PI3K/Akt/GLUT-4 signalling pathway in animals.
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Affiliation(s)
- Debapriya Garabadu
- Pharmacology Laboratory, Department of Pharmaceutics, Indian Institute of Technology (Banaras Hindu University), Varanasi, UP, India
| | - Sairam Krishnamurthy
- Pharmacology Laboratory, Department of Pharmaceutics, Indian Institute of Technology (Banaras Hindu University), Varanasi, UP, India
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Dong N, Du P, Hao X, He Z, Hou W, Wang L, Yuan W, Yang J, Jia R, Tai F. Involvement of GABA A receptors in the regulation of social preference and emotional behaviors by oxytocin in the central amygdala of female mandarin voles. Neuropeptides 2017; 66:8-17. [PMID: 28764883 DOI: 10.1016/j.npep.2017.07.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 05/19/2017] [Accepted: 07/24/2017] [Indexed: 12/31/2022]
Abstract
The central nucleus of the amygdala (CeA) is the main output of the amygdala and plays an important role in behavioral and neuroendocrine responses to stress. Receptors for the neuropeptide oxytocin (OT) and GABAA are found in high concentration in the CeA. The mechanisms underlying regulation of CeA OT in emotional and social behavior remain unclear. In this study we evaluated the effects of intra-CeA OT administration of different doses (0.1, 1 and 10ng/side), OT receptor antagonist (OTR-A) (1, 10 and 100ng/side) and OT plus OTR-A on social and emotional behavior using a social preference paradigm, open field test and elevated plus maze test in female monogamous mandarin voles (Microtus mandarinus). We then examined whether different doses of the GABAA receptor antagonist bicuculline (5, 10 and 100ng/side) affected the behavioral changes induced by intra-CeA microinjection of OT (1ng/side). We found that administration of OT to the CeA increased social preference, central area investigation times in the open field test, and visits, transitions and time spent in the open arms in the elevated plus maze test; all responses were dose-dependent. Administration of OT plus OTR-A to the CeA produced no effects. Administration of bicuculline in combination with OT to the CeA decreased social preference, central area investigation times in the open field test, and visits, transitions and time spent in the open arms of the elevated plus maze test. These data suggest that OT in the CeA facilitates sociality and reduces levels of anxiety by interacting with local GABAA receptors.
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Affiliation(s)
- Na Dong
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Peirong Du
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Xin Hao
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Zhixiong He
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Wenjuan Hou
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Limin Wang
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Wei Yuan
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Jinfeng Yang
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China
| | - Rui Jia
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China.
| | - Fadao Tai
- Institute of Brain and Behavioral Sciences, College of Life Sciences, Shaanxi Normal University, Xi'an, Shaanxi 710100, China.
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