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Lesuis SL, Brosens N, Immerzeel N, van der Loo RJ, Mitrić M, Bielefeld P, Fitzsimons CP, Lucassen PJ, Kushner SA, van den Oever MC, Krugers HJ. Glucocorticoids Promote Fear Generalization by Increasing the Size of a Dentate Gyrus Engram Cell Population. Biol Psychiatry 2021; 90:494-504. [PMID: 34503674 DOI: 10.1016/j.biopsych.2021.04.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 12/15/2022]
Abstract
BACKGROUND Traumatic experiences, such as conditioned threat, are coded as enduring memories that are frequently subject to generalization, which is characterized by (re-) expression of fear in safe environments. However, the neurobiological mechanisms underlying threat generalization after a traumatic experience and the role of stress hormones in this process remain poorly understood. METHODS We examined the influence of glucocorticoid hormones on the strength and specificity of conditioned fear memory at the level of sparsely distributed dentate gyrus (DG) engram cells in male mice. RESULTS We found that elevating glucocorticoid hormones after fear conditioning induces a generalized contextual fear response. This was accompanied by a selective and persistent increase in the excitability and number of activated DG granule cells. Selective chemogenetic suppression of these sparse cells in the DG prevented glucocorticoid-induced fear generalization and restored contextual memory specificity, while leaving expression of auditory fear memory unaffected. CONCLUSIONS These results implicate the sparse ensemble of DG engram cells as a critical cellular substrate underlying fear generalization induced by glucocorticoid stress hormones.
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Affiliation(s)
- Sylvie L Lesuis
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands; Program in Neurosciences and Mental Health, Hospital for Sick Children, Toronto, Ontario, Canada.
| | - Niek Brosens
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands
| | - Nathalie Immerzeel
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands
| | - Rolinka J van der Loo
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Miodrag Mitrić
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Pascal Bielefeld
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands
| | - Carlos P Fitzsimons
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands
| | - Paul J Lucassen
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research (CNCR), Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Harm J Krugers
- Brain Plasticity Group, SILS-CNS, University of Amsterdam, Amsterdam, The Netherlands.
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Rogliani P, Ritondo BL, Cavalli F, Giorgino F, Girolami A, Pane G, Pezzuto G, Zerillo B, Puxeddu E, Ora J. Synergy across the drugs approved for the treatment of asthma. Minerva Med 2021; 113:17-30. [PMID: 33496162 DOI: 10.23736/s0026-4806.21.07266-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
INTRODUCTION Inhaled corticosteroids are the cornerstone for the treatment of stable asthma, however, when disease severity increases, escalating therapy to combinations of drugs acting on distinct signalling pathways is required. It is advantageous to providing evidence of a synergistic interaction across drug combinations, as it allows optimizing bronchodilation while lowering the dose of single agents. In the respiratory pharmacology field, two statistical models are accepted as gold standard to characterize drug interactions, namely the Bliss Independence criterion and the Unified Theory. In this review, pharmacological interactions across drugs approved for the treatment of asthma have been systematically assessed. EVIDENCE ACQUISITION A comprehensive literature search was performed in MEDLINE for studies that used a validated pharmacological method for assessing drug interaction. The results were extracted and reported via qualitative synthesis. EVIDENCE SYNTHESIS Overall, 45 studies were identified from literature search and 5 met the inclusion criteria. Current evidence coming from ex vivo models of asthma indicates that drug combinations modulating bronchial contractility induce a synergistic bronchorelaxant effect. In murine models of lung inflammation, the combination between inhaled corticosteroids and β2- adrenoceptor agonists synergistically improve lung function and the inflammatory profile. CONCLUSIONS There is still limited knowledge regarding the mechanistic basis underlying pharmacological interactions across drugs approved for asthma. The synergism elicited by combined agents is an effect of class. Specifically designed clinical trials are needed to confirm the results coming from preclinical evidence, but also to establish the minimal dose for combined agents to induce a synergistic interaction and maximize bronchodilation.
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Affiliation(s)
- Paola Rogliani
- Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy - .,Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy -
| | - Beatrice L Ritondo
- Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Francesco Cavalli
- Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Federica Giorgino
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Andrea Girolami
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Gloria Pane
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Gabriella Pezzuto
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Bartolomeo Zerillo
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Ermanno Puxeddu
- Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy.,Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
| | - Josuel Ora
- Division of Respiratory Medicine, University Hospital Policlinico Tor Vergata, Rome, Italy
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3
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Calzetta L, Matera MG, Rogliani P, Cazzola M. The role of triple therapy in the management of COPD. Expert Rev Clin Pharmacol 2020; 13:865-874. [DOI: 10.1080/17512433.2020.1787830] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Luigino Calzetta
- Unit of Respiratory Disease and Lung Function Department Medicine and Surgery, University of Parma, Parma, Italy
| | - Maria Gabriella Matera
- Unit of Pharmacology, Department Experimental Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Paola Rogliani
- Unit of Respiratory Medicine, Unit of Pharmacology, Department Experimental Medicine, Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy
| | - Mario Cazzola
- Unit of Respiratory Medicine, Unit of Pharmacology, Department Experimental Medicine, Experimental Medicine, University of Rome “Tor Vergata”, Rome, Italy
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4
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Interaction between corticosteroids and muscarinic antagonists in human airways. Pulm Pharmacol Ther 2015; 36:1-9. [PMID: 26656790 DOI: 10.1016/j.pupt.2015.11.004] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 11/05/2015] [Accepted: 11/25/2015] [Indexed: 12/30/2022]
Abstract
BACKGROUND To date there is emerging clinical evidence to add long-acting anti-muscarinic agents (LAMAs) with inhaled corticosteroid (ICSs) in asthma, but the pharmacological rationale that supports the use of such a combination has not yet been explained. The aim of this study was to pharmacologically investigate the interaction between the ICS beclomethasone and the LAMA glycopyrronium on the human airway smooth muscle (ASM) tone. METHODS We investigated the rapid non-genomic bronchorelaxant effect of beclomethasone and glycopyrronium, administered alone and in combination, in human isolated bronchi and bronchioles. Experiments were carried out also in passively sensitized airways and the pharmacological analysis of drug interaction was performed by Bliss Independence method. RESULTS The acute administration of beclomethasone and glycopyrronium induced a significant relaxation of passively sensitized ASM pre-contracted with histamine, by causing submaximal/maximal inhibition of the contractile tone in both medium bronchi and bronchioles. Beclomethasone was characterized by a rapid non-genomic and epithelium independent bronchorelaxant effect. In passively sensitized airways, this effect seemed to be dependent by the activation of a Gsα--cyclic adenosine monophosphate (cAMP)--protein kinase A cascade. While no synergistic interaction was detected in non-sensitized bronchi, the beclomethasone/glycopyrronium combination synergistically enhanced the relaxation of passively sensitized medium and small bronchi. The synergistic interaction between beclomethasone and glycopyrronium was associated with an increase of cAMP concentrations. CONCLUSIONS Our study provides for the first time the pharmacological rationale for combining low doses of an ICS plus a LAMA.
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Jin X, Zhang Y, Li Q, Zhao J. Mechanisms underlying the beneficial effects of Kaiyu Granule for depression. Neural Regen Res 2014; 8:3241-8. [PMID: 25206645 PMCID: PMC4146178 DOI: 10.3969/j.issn.1673-5374.2013.34.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 11/08/2013] [Indexed: 11/20/2022] Open
Abstract
The proprietary Chinese medicine preparation Kaiyu Granule is made of bupleurum, nutgrass galingale rhizome, szechwan lovage rhizome, turmeric root tuber, white peony alba, cape jasmine fruit, fried semen ziziphi jujubae, and prepared liquorice root. It is a common recipe for the clinical treatment of depression in China. In this study, after 21 days of unpredictable stress exposure, Wistar rats exhibited similar behavioral changes to patients with depression. Moreover, G-protein-coupled inwardly rectifying K+ channel 1 mRNA and protein expression were significantly reduced in rat hippocampal CA1 and CA3 regions. However, G-protein-coupled inwardly rectifying K+ channel 1 mRNA, protein expression, and rat behavior were clearly better after administration of 12, 8, or 4 g/kg of Kaiyu Granule when depression model rats underwent stress. 12 g/kg of Kaiyu Granule had the most obvious effects on the increased expression of G-protein-coupled inwardly rectifying K+ channel 1 mRNA and protein in rat hippocampal CA1 and CA3 regions. These results suggested that Kaiyu Granule improved depression by affecting G-protein-coupled inwardly rectifying K+ channel 1 expression in the rat hippocampus.
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Affiliation(s)
- Xi Jin
- Department of Neurology, Hospital Affiliated to Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Yidan Zhang
- Department of Neurology, Hospital Affiliated to Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Qiaoying Li
- Department of Neurology, Hospital Affiliated to Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
| | - Jianjun Zhao
- Department of Neurology, Hospital Affiliated to Changchun University of Chinese Medicine, Changchun 130021, Jilin Province, China
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6
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Saenz del Burgo L, Cortés R, Mengod G, Montaña M, García del Caño G, Sallés J. Chronic effects of corticosterone on GIRK1-3 subunits and 5-HT1A receptor expression in rat brain and their reversal by concurrent fluoxetine treatment. Eur Neuropsychopharmacol 2013; 23:229-39. [PMID: 22591911 DOI: 10.1016/j.euroneuro.2012.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 03/09/2012] [Accepted: 04/14/2012] [Indexed: 11/17/2022]
Abstract
Dysregulation of the serotonergic system and abnormalities of the hypothalamic-pituitary-adrenal axis have been demonstrated in major depression. Animal studies indicate that 5-HT1A receptor expression may be reduced by long-term administration of corticosterone. However, similar studies on the regulation of GIRK channels, one of the most important effectors of the neuronal 5-HT1A receptor, are limited. In order to address these issues, slow-release corticosterone pellets were implanted subcutaneously to adrenal intact male rats (200mg pellets, 35 days release). Starting on day 15, animals were treated for 21 days with fluoxetine (5mg/kg/day, i.p.), or vehicle. Using in situ hybridization histochemistry and receptor autoradiography, we found that chronic corticosterone treatment was accompanied by a significant decrease on the mRNAs coding for mineralocorticoid receptors in hippocampal areas. Under these conditions, 5-HT1A receptor mRNA expression decreased in dorsal raphe nucleus and dentate gyrus. However, 5-HT1A receptor levels, as measured by [(3)H]-8-OH-DPAT binding, diminished significantly only in dentate gyrus. It is noteworthy that chronic treatment with fluoxetine reversed the alterations on 5-HT1A receptor mRNA levels only in dorsal raphe. Finally, chronic corticosterone treatment produced an increase on the mRNA coding for the GIRK2 subunit in several hypothalamic and thalamic areas, which was reversed by fluoxetine. Measurements of cell density and volume of the granular layer of the dentate gyrus did not reveal significant changes after corticosterone or corticosterone plus fluoxetine treatments. These data are relevant for a better understanding of the differential regulation of pre- and postsynaptic 5-HT1A receptors by corticosterone flattened rhythm.
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MESH Headings
- Animals
- Autoradiography
- Corticosterone/pharmacology
- Dentate Gyrus/drug effects
- Dentate Gyrus/metabolism
- Depressive Disorder, Major/metabolism
- Fluoxetine/pharmacology
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/drug effects
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/genetics
- G Protein-Coupled Inwardly-Rectifying Potassium Channels/metabolism
- Gene Expression/drug effects
- Gene Expression Profiling
- Hippocampus/drug effects
- Hippocampus/metabolism
- Hypothalamo-Hypophyseal System/metabolism
- Male
- Pituitary-Adrenal System/metabolism
- Raphe Nuclei/drug effects
- Raphe Nuclei/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Serotonin, 5-HT1A/drug effects
- Receptor, Serotonin, 5-HT1A/genetics
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptors, Glucocorticoid/drug effects
- Receptors, Glucocorticoid/genetics
- Receptors, Glucocorticoid/metabolism
- Receptors, Mineralocorticoid/drug effects
- Receptors, Mineralocorticoid/genetics
- Receptors, Mineralocorticoid/metabolism
- Selective Serotonin Reuptake Inhibitors/pharmacology
- Thalamus/drug effects
- Thalamus/metabolism
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Affiliation(s)
- Laura Saenz del Burgo
- Department of Pharmacology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Spain
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Clarke TK, Laucht M, Ridinger M, Wodarz N, Rietschel M, Maier W, Lathrop M, Lourdusamy A, Zimmermann US, Desrivieres S, Schumann G. KCNJ6 is associated with adult alcohol dependence and involved in gene × early life stress interactions in adolescent alcohol drinking. Neuropsychopharmacology 2011; 36:1142-8. [PMID: 21307845 PMCID: PMC3079832 DOI: 10.1038/npp.2010.247] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Alcohol abuse and dependence have proven to be complex genetic traits that are influenced by environmental factors. Primate and human studies have shown that early life stress increases the propensity for alcohol abuse in later life. The reinforcing properties of alcohol are mediated by dopaminergic signaling; however, there is little evidence to indicate how stress alters alcohol reinforcement. KCNJ6 (the gene encoding G-protein-coupled inwardly rectifying potassium channel 2 (GIRK2)) is a brain expressed potassium channel with inhibitory effects on dopaminergic tone. The properties of GIRK2 have been shown to be enhanced by the stress peptide corticotrophin-releasing hormone. Therefore, we sought to examine the role of KCNJ6 polymorphisms in adult alcohol dependence and stress-related alcohol abuse in adolescents. We selected 11 SNPs in the promoter region of KCNJ6, which were genotyped in 1152 adult alcohol dependents and 1203 controls. One SNP, rs2836016, was found to be associated with alcohol dependence (p=0.01, false discovery rate). We then assessed rs2836016 in an adolescent sample of 261 subjects, which were characterized for early life stress and adolescent hazardous drinking, defined using the Alcohol Use Disorders Identification Test (AUDIT), to examine gene-environment interactions. In the adolescent sample, the risk genotype of rs2836016 was significantly associated with increased AUDIT scores, but only in those individuals exposed to high levels of psychosocial stress in early life (p=0.01). Our findings show that KCNJ6 is associated with alcohol dependence and may moderate the effect of early psychosocial stress on risky alcohol drinking in adolescents. We have identified a candidate gene for future studies investigating a possible functional link between the response to stress and alcohol reinforcement.
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Affiliation(s)
- Toni-Kim Clarke
- Section of Addiction Biology, MRC-SGDP Centre, Institute of Psychiatry, King's College London, London, UK.
| | - Manfred Laucht
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany,Department of Psychology, Division of Clinical Psychology and Psychotherapy, University of Potsdam, Potsdam, Germany
| | - Monika Ridinger
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Norbert Wodarz
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Marcella Rietschel
- Department of Child and Adolescent Psychiatry and Psychotherapy, Central Institute of Mental Health, Mannheim, Germany
| | - Wolfgang Maier
- Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
| | | | - Anbarasu Lourdusamy
- Section of Addiction Biology, MRC-SGDP Centre, Institute of Psychiatry, King's College London, London, UK
| | - Ulrich S Zimmermann
- Department of Psychiatry and Psychotherapy, University Hospital Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - Sylvane Desrivieres
- Section of Addiction Biology, MRC-SGDP Centre, Institute of Psychiatry, King's College London, London, UK
| | - Gunter Schumann
- Section of Addiction Biology, MRC-SGDP Centre, Institute of Psychiatry, King's College London, London, UK,Department of Psychiatry and Psychotherapy, University of Bonn, Bonn, Germany
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8
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Joëls M, Krugers HJ, Lucassen PJ, Karst H. Corticosteroid effects on cellular physiology of limbic cells. Brain Res 2009; 1293:91-100. [PMID: 19332034 DOI: 10.1016/j.brainres.2009.03.036] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Accepted: 03/16/2009] [Indexed: 01/03/2023]
Abstract
After stress, circulating levels of stress hormones such as corticosterone are markedly increased. This will have an impact on the neurophysiology of limbic neurons that highly express corticosteroid receptors. Over the past decades several principles about the neurophysiological impact of corticosterone have emerged. First, corticosterone can quickly raise the excitability of hippocampal CA1 neurons shortly after stress exposure, via a nongenomic pathway involving mineralocorticoid receptors presumably located in the pre- as well as postsynaptic membrane. At the same time, gene-mediated actions via the glucocorticoid receptor are started which some hours later will result in enhanced calcium influx and impaired ability to induce long-term potentiation. These delayed actions are interpreted as a means to slowly normalize hippocampal activity and preserve information encoded early on after stress. Second, the full spectrum of neurophysiological actions by corticosterone is accomplished in interaction with other stress mediators, like noradrenaline. Third, these effects in the CA1 hippocampal region cannot be generalized to other brain regions such as the basolateral amygdala or paraventricular nucleus: There seems to be a highly differentiated response, which could serve to facilitate neuroendocrine/cognitive processing of some aspects of stress-related information, but attenuate other aspects. Finally, the time- and region-specific corticosteroid actions strongly depend on the individual's life history.
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Affiliation(s)
- Marian Joëls
- SILS-CNS, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam, The Netherlands.
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9
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Prendergast MA, Little HJ. Adolescence, glucocorticoids and alcohol. Pharmacol Biochem Behav 2006; 86:234-45. [PMID: 16930684 DOI: 10.1016/j.pbb.2006.07.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 06/05/2006] [Accepted: 07/06/2006] [Indexed: 11/22/2022]
Abstract
This review examines the evidence that glucocorticoids are involved, during both adolescence and adulthood, in the cognitive deficits caused by long-term alcohol consumption and in the mechanism(s) of alcohol dependence. During adolescence, the hypothalamopituitary-adrenal (HPA) axis undergoes well-characterized changes in basal activity and many of these are influenced by alcohol consumption. While the former have been fairly well studied, there is little information about whether alcohol effects on the HPA in adolescents differ from those in adults. The means by which glucocorticoids may influence alcohol-related neurotoxicity are presented, and potential differences between adolescence and adults in this regard noted. The substantial evidence for involvement of glucocorticoids in alcohol-induced cognitive deficits is described, with particular reference to the consequences of alcohol withdrawal. The use of immature organotypic cultures of rodent brain in the study of alcohol neurotoxicity is considered in detail, and the information obtained from this methodology concerning the role of glucocorticoid receptors and excitable membrane proteins in this neurotoxicity. The influence of glucocorticoids on alcohol consumption and possible contributions to alcohol dependence are then considered. In conclusion, more information concerning the effects of glucocorticoids on plasticity and alcohol neurotoxicity during the adolescent period is needed.
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Affiliation(s)
- Mark A Prendergast
- Department of Psychology, University of Kentucky, B363 BBSRB, 741 S. Limestone, University of Kentucky, Lexington, KY 40536-0509, USA
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10
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Joëls M, Karst H, Alfarez D, Heine VM, Qin Y, van Riel E, Verkuyl M, Lucassen PJ, Krugers HJ. Effects of chronic stress on structure and cell function in rat hippocampus and hypothalamus. Stress 2004; 7:221-31. [PMID: 16019587 DOI: 10.1080/10253890500070005] [Citation(s) in RCA: 245] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
It has become increasingly clear that the increase in corticosteroid levels, e.g. after a brief stressor induce molecular and cellular changes in brain, including the hippocampal formation. These effects eventually result in behavioral adaptation. Prolonged exposure to stress, though, may lead to mal-adaptation and even be a risk factor for diseases like major depression in genetically predisposed individuals. We conducted a series of experiments where changes in brain function were examined after 3 weeks of unpredictable stress. After unpredictable stress, inhibitory input to neurons involved in the hypothalamus-pituitary-adrenal (HPA) axis regulation was suppressed, which may dysregulate the axis and lead to overexposure of the brain to glucocorticoids. Furthermore, glutamate transmission in the dentate gyrus (DG) was enhanced, possibly through transcriptional regulation of receptor subunits. Combined with enhanced calcium channel expression this could increase vulnerability to cell death. Neurogenesis and apoptosis in the dentate were diminished. Synaptic plasticity was suppressed both in the dentate and CA1 area. Collectively, these effects may give rise to deficits in memory formation. Finally, we observed reduced responses to serotonin in the CA1 area, which could contribute to the onset of symptoms of depression in predisposed individuals. All of these endpoints provide potential targets for novel treatment strategies of stress-related brain disorders.
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Affiliation(s)
- Marian Joëls
- SILS-CNS, University of Amsterdam, The Netherlands.
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11
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Joëls M, Verkuyl JM, Van Riel E. Hippocampal and Hypothalamic Function after Chronic Stress. Ann N Y Acad Sci 2003; 1007:367-78. [PMID: 14993070 DOI: 10.1196/annals.1286.036] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Hyperactivity of the hypothalamo-pituitary-adrenal (HPA) axis is often observed in association with and even prior to the onset of major depression. It is presently unclear (1) which molecular and cellular processes contribute to hyperactivity of parvocellular hypothalamic neurons (key regulators of the HPA system) and (2) how HPA axis hyperactivity can lead to attenuation of central serotonergic transmission, a crucial factor in the onset of clinical symptoms. In an attempt to address these issues in an experimental model we used rats exposed to chronic unpredictable stressors, a paradigm causing prolonged HPA-axis hyperactivity. In the first study spontaneous and evoked GABA-mediated input to parvocellular neurons in the paraventricular hypothalamic nucleus was recorded with the whole cell patch-clamp technique. The frequency, but not other properties, of spontaneous GABA-mediated inhibitory postsynaptic currents was reduced after chronic stress, resulting in a reduced amplitude of the evoked GABA current. This potentially would disinhibit parvocellular neurons, provided that other inputs are unchanged. In the second study, responses of CA1 hippocampal neurons to serotonin were recorded with microelectrodes. It appeared that the membrane hyperpolarization caused by activation of serotonin-1A receptors is attenuated in tissue from chronically stressed rats. However, no apparent changes in expression of the serotonin-1A or corticosteroid receptors were observed. This supports the notion that chronic stress eventually results in attenuation of serotonergic responsiveness by a mechanism not involving transcriptional regulation of the receptor. Follow-up studies will need to examine whether treatment with corticosteroid receptor antagonists can normalize the attenuated transmission after chronic stress.
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Affiliation(s)
- M Joëls
- Swammerdam Institute for Life Sciences, Section Neurobiology, University of Amsterdam, 1098 SM Amsterdam, the Netherlands.
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12
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Czyrak A, Maćkowiak M, Chocyk A, Fijał K, Gadek-Michalska A, Wedzony K. 8-OHDPAT-induced disruption of prepulse inhibition in rats is attenuated by prolonged corticosterone treatment. Neuropsychopharmacology 2003; 28:1300-10. [PMID: 12700680 DOI: 10.1038/sj.npp.1300165] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The present study investigated the impact of acute and repeated administrations of corticosterone (10 mg/kg, twice daily, for 7 days) on serotonin (5-HT)(1A) receptor function, density and expression. The effect on 5-HT(1A) receptor function was assayed in rats by assessing the corticosterone-induced modulation of disruption of prepulse inhibition (PPI) of acoustic startle response induced by 8-OHDPAT, a 5-HT(1A) receptor agonist. Our experiments revealed that repeated but not acute treatment with corticosterone attenuated the 8-OHDPAT-evoked disruption of PPI without having any effect on PPI or startle amplitude alone. Chronic corticosterone treatment modulated also the neuronal activity of serotonergic pathways in the brain decreasing the level of 5-HIAA in the raphe nuclei and increasing both 5-HT and 5-HIAA levels in the hippocampus. Nevertheless, the effects of 8-OHDPAT on 5-HT metabolism were not changed by corticosterone. However, 5-HT(1A) receptor binding in the ventral hippocampus and entorhinal cortex but not in the raphe nuclei was decreased after chronic corticosterone treatment. It is concluded that chronically elevated corticosterone level is capable of inducing functional desensitization of 5-HT(1A) receptors which is paralleled by decreases in the 5-HT(1A) receptor binding in the ventral hippocampus and entorhinal cortex, the brain structures shown to be engaged in the regulation of PPI. Alterations in 5-HT(1A) receptors may be one of important mechanisms by which glucocorticoids/stress influence various psychiatric conditions.
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Affiliation(s)
- Anna Czyrak
- Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
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13
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Tigani B, Hannon JP, Schaeublin E, Mazzoni L, Fozard JR. Effects of immunomodulators on airways hyperresponsiveness to adenosine induced in actively sensitised Brown Norway rats by exposure to allergen. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2003; 368:17-25. [PMID: 12827216 DOI: 10.1007/s00210-003-0767-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2003] [Accepted: 05/05/2003] [Indexed: 10/26/2022]
Abstract
We have recently demonstrated a marked and selective augmentation of the bronchoconstrictor response to adenosine in actively sensitised Brown Norway (BN) rats challenged with ovalbumin (OA). The augmented response is mediated by 5-hydroxytryptamine (5-HT) released as a consequence of mast cell activation. We describe here the effects of budesonide, a clinically used glucocorticosteroid, IMM125, a hydroxyethyl derivative of D-serine-cyclosporine, MLD987, a close analogue of ascomycin and SAR943, a rapamycin derivative, on the hyperresponsiveness to adenosine induced in actively sensitised BN rats by exposure to allergen. Bronchoconstrictor responses to adenosine elicited 3 h following intratracheal (i.t.) instillation of OA, 0.3 mg kg(-1) were reduced dose-dependently by budesonide, IMM125, and MLD987, given i.t. 25 and 1 h prior to allergen challenge. In contrast, SAR943 had no effect on responses to adenosine. Responses to methacholine and 5-HT were minimally affected by these agents. Bronchoconstrictor responses to bradykinin were dose-dependently reduced by budesonide, but unaffected following IMM125, MLD987 or SAR943 pre-treatment. Challenge with OA at a dose of 0.3 mg kg(-1), induced increases in bronchoalveolar lavage (BAL) fluid, leukocyte numbers, eosinophil peroxidase (EPO) and myeloperoxidase (MPO) activities and protein concentration measured 24 h post challenge. Budesonide (1 mg kg(-1) given i.t. 25 and 1 h prior to OA challenge) induced reductions in the BAL fluid parameters of inflammation; IMM125 and MLD987, at a dose of 1 mg kg(-1) had no significant effect whereas SAR943 reduced lymphocyte numbers. Thus, budesonide, IMM125 and MLD987 block the hyperresponsiveness to adenosine induced by allergen challenge in sensitised rats. In the case of budesonide the effect is associated with a powerful, generalised anti-inflammatory effect although an effect directly on the mast cells is also likely. With IMM125 and MLD987, the effect is seen at doses that are not anti-inflammatory and may reflect direct suppression of mast cell activation by these agents.
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Affiliation(s)
- Bruno Tigani
- Novartis Institute for Biomedical Research, WSJ.386.508, 4002 Basel, Switzerland
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Jacoby DB, Yost BL, Kumaravel B, Chan-Li Y, Xiao HQ, Kawashima K, Fryer AD. Glucocorticoid treatment increases inhibitory m(2) muscarinic receptor expression and function in the airways. Am J Respir Cell Mol Biol 2001; 24:485-91. [PMID: 11306443 DOI: 10.1165/ajrcmb.24.4.4379] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
M(2) muscarinic receptors on parasympathetic nerve endings inhibit acetylcholine release in the airways. In this study, the effects of dexamethasone on M(2) receptors in vivo and in primary cultures of airway parasympathetic neurons were tested. Treating guinea pigs with dexamethasone (0.1 mg/kg, daily for 2 d) substantially increased inhibitory M(2) muscarinic receptor function, decreasing airway responsiveness to electrical stimulation of the vagi. At the same time, dexamethasone decreased the response to acetylcholine but not to methacholine, suggesting that cholinesterase activity was increased. When both cholinesterase and M(2) receptors were blocked (using physostigmine and gallamine, respectively) vagally induced bronchoconstriction was increased to control values. In primary cultures of airway parasympathetic neurons, dexamethasone significantly decreased the release of acetylcholine in response to electrical stimulation. Blocking inhibitory M(2) receptors using atropine (10(-5) M) increased acetylcholine release. After the M(2) receptors were blocked there was no difference in acetylcholine release between control and dexamethasone-treated cultures. M(2) receptor gene expression was increased by more than fivefold in dexamethasone-treated cultures. Immunostaining of dexamethasone-treated neurons demonstrated more intense staining. Thus, decreased vagally mediated reflex bronchoconstriction after glucocorticoid treatment may be the result on increased M(2) receptor expression and function as well as increased degradation of acetylcholine by cholinesterase.
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Affiliation(s)
- D B Jacoby
- Division of Pulmonary and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
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