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Yang H, Narayan S, Schmidt MV. From Ligands to Behavioral Outcomes: Understanding the Role of Mineralocorticoid Receptors in Brain Function. Stress 2023; 26:2204366. [PMID: 37067948 DOI: 10.1080/10253890.2023.2204366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/18/2023] Open
Abstract
Stress is a normal response to situational pressures or demands. Exposure to stress activates the hypothalamic-pituitary-adrenal (HPA) axis and leads to the release of corticosteroids, which act in the brain via two distinct receptors: mineralocorticoid receptors (MR) and glucocorticoid receptors (GR). Persistent HPA axis overactivation or dysregulation can disrupt an individual's homeostasis, thereby contributing to an increased risk for mental illness. On the other hand, successful coping with stressful events involves adaptive and cognitive processes in the brain that render individuals more resilient to similar stressors in the future. Here we review the role of the MR in these processes, starting with an overview of the physiological structure, ligand binding, and expression of MR, and further summarizing its role in the brain, its relevance to psychiatric disorders, and related rodent studies. Given the central role of MR in cognitive and emotional functioning, and its importance as a target for promoting resilience, future research should investigate how MR modulation can be used to alleviate disturbances in emotion and behavior, as well as cognitive impairment, in patients with stress-related psychiatric disorders.
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Affiliation(s)
- Huanqing Yang
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Sowmya Narayan
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Department Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- International Max Planck Research School for Translational Psychiatry (IMPRS-TP), 80804 Munich, Germany
| | - Mathias V Schmidt
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
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Spironolactone as a potential new pharmacotherapy for alcohol use disorder: convergent evidence from rodent and human studies. Mol Psychiatry 2022; 27:4642-4652. [PMID: 36123420 DOI: 10.1038/s41380-022-01736-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 08/02/2022] [Accepted: 08/08/2022] [Indexed: 12/14/2022]
Abstract
Evidence suggests that spironolactone, a nonselective mineralocorticoid receptor (MR) antagonist, modulates alcohol seeking and consumption. Therefore, spironolactone may represent a novel pharmacotherapy for alcohol use disorder (AUD). In this study, we tested the effects of spironolactone in a mouse model of alcohol drinking (drinking-in-the-dark) and in a rat model of alcohol dependence (vapor exposure). We also investigated the association between spironolactone receipt for at least 60 continuous days and change in self-reported alcohol consumption, using the Alcohol Use Disorders Identification Test-Consumption (AUDIT-C), in a pharmacoepidemiologic cohort study in the largest integrated healthcare system in the US. Spironolactone dose-dependently reduced the intake of sweetened or unsweetened alcohol solutions in male and female mice. No effects of spironolactone were observed on drinking of a sweet solution without alcohol, food or water intake, motor coordination, alcohol-induced ataxia, or blood alcohol levels. Spironolactone dose-dependently reduced operant alcohol self-administration in dependent and nondependent male and female rats. In humans, a greater reduction in alcohol consumption was observed among those who received spironolactone, compared to propensity score-matched individuals who did not receive spironolactone. The largest effects were among those who reported hazardous/heavy episodic alcohol consumption at baseline (AUDIT-C ≥ 8) and those exposed to ≥ 50 mg/day of spironolactone. These convergent findings across rodent and human studies demonstrate that spironolactone reduces alcohol use and support the hypothesis that this medication may be further studied as a novel pharmacotherapy for AUD.
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Albernaz-Mariano KA, Souza RR, Canto-de-Souza A. Blockade of the mineralocorticoid receptors in the medial prefrontal cortex prevents the acquisition of one-trial tolerance in mice. Behav Brain Res 2022; 431:113938. [PMID: 35618080 DOI: 10.1016/j.bbr.2022.113938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 05/17/2022] [Accepted: 05/20/2022] [Indexed: 11/17/2022]
Abstract
One-trial tolerance (OTT) is characterized by the lack of anxiolytic-like effects of benzodiazepines in animals submitted to a trial 2 in the elevated plus-maze (EPM) and is described to be influenced by learning mechanisms. Mineralocorticoid receptors (MR) in the infralimbic subregion (IL) of the medial prefrontal cortex (mPFC) are important modulators of emotional learning, but the MR involvement in the establishment of OTT remains unclear. We investigated the effects of intra-IL infusions of RU 28318 (an MR antagonist) on the OTT to the anxiolytic effects of midazolam (MDZ, GABAA-benzodiazepine agonist) in mice exposed to a two-trial protocol in the EPM. First, mice were treated with saline or MDZ (2mgkg-1, i.p.) 30minutes before trial 1 or 2 in the EPM, to characterize the OTT. To investigate the role of MR in the OTT, independent groups of mice received intra-IL infusions of vehicle or RU 28318 (5 or 10ng 0.1µL-1) immediately before or after first trial in the EPM. Twenty-four hours later, the same mice received injections of saline or MDZ and were re-tested in the EPM. The MDZ decreased anxiety-like behaviors in trial 1, but the same anxiolytic-like effect was not observed in MDZ-mice prior to the second EPM test, confirming the OTT. Blockade of MR in the IL before, but not after, trial 1 restored the anxiolytic effects if MDZ administered in trial 2. These findings indicate that the MR in the IL-mPFC contributing to the OTT by mediating the acquisition, but not the consolidation of emotional learning.
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Affiliation(s)
- Kairo Alan Albernaz-Mariano
- Psychobiology Group/Department of Psychology/CECH-UFSCar, São Carlos, SP 13565-905, Brazil; Joint Graduate Program in Physiological Sciences UFSCar/UNESP, Rod. Washington Luís, Km 235, São Carlos, SP 13565-905, Brazil.
| | - Rimenez Rodrigues Souza
- The University of Texas at Dallas, School of Behavior and Brain Sciences, 800 West Campbell Road, Richardson, TX 75080-3021, United States; The University of Texas at Dallas, Texas Biomedical Device Center, 800 West Campbell Road, Richardson, TX 75080-3021, United States.
| | - Azair Canto-de-Souza
- Psychobiology Group/Department of Psychology/CECH-UFSCar, São Carlos, SP 13565-905, Brazil; Joint Graduate Program in Physiological Sciences UFSCar/UNESP, Rod. Washington Luís, Km 235, São Carlos, SP 13565-905, Brazil; Graduate Program in Psychology UFSCar, Rod. Washington Luís, Km 235, São Carlos, SP 13565-905, Brazil; Neuroscience and Behavioral Institute, Av. do Café, 2.450, 14050-220 Ribeirão Preto, SP, Brazil.
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Karailiev P, Hlavacova N, Chmelova M, Homer NZM, Jezova D. Tight junction proteins in the small intestine and prefrontal cortex of female rats exposed to stress of chronic isolation starting early in life. Neurogastroenterol Motil 2021; 33:e14084. [PMID: 33497497 DOI: 10.1111/nmo.14084] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/30/2020] [Accepted: 01/04/2021] [Indexed: 01/07/2023]
Abstract
BACKGROUND Simultaneous evaluation of barrier protein expression in the gut and the brain and their modulation under stress conditions have not been studied before now. As the permeability and function of the gut and blood-brain barrier are different and both express the MRs, we hypothesized that stress of post-weaning social isolation induces changes in tight junction protein expression in the gut which are (1) independent of changes in the brain and (2) are mediated via the mineralocorticoid receptor (MR). METHODS First, using UPLC-MS/MS we have successfully validated and selected a dose (1.2 mg/rat/day) of the MR antagonist spironolactone to treat female rats exposed to stress of chronic isolation or control conditions from postnatal day 21 for 9 weeks. KEY RESULTS Isolation stress caused an enhancement of gene expression of occludin and ZO-1 and a decrease in claudin-5 and MR expression in both the small intestine and prefrontal cortex. Isolation stress failed to decrease claudin-5 (small intestine) and MR (prefrontal cortex) gene expression in spironolactone-treated rats. MR blockade resulted in a decrease in claudin-15 expression in the small intestine. Anxiogenic effect of chronic stress, measured in elevated plus-maze test, was partly prevented by spironolactone treatment. CONCLUSIONS & INFERENCES Claudins, the main regulators of intestinal barrier permeability responded to chronic stress of social isolation and/or simultaneous blockade of MR in female rats by alterations independent of changes in the brain cortex. The results suggest a physiological role of MR in the control of claudin expression in the small intestine, but not in the brain cortex.
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Affiliation(s)
- Peter Karailiev
- Institute of Experimental Endocrinology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Natasa Hlavacova
- Institute of Experimental Endocrinology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Magdalena Chmelova
- Institute of Experimental Endocrinology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
| | - Natalie Z M Homer
- Mass Spectrometry Core, Edinburgh CRF, Centre for Cardiovascular Sciences, Queen's Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - Daniela Jezova
- Institute of Experimental Endocrinology, Biomedical Research Center of the Slovak Academy of Sciences, Bratislava, Slovakia
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Kline SA, Mega MS. Stress-Induced Neurodegeneration: The Potential for Coping as Neuroprotective Therapy. Am J Alzheimers Dis Other Demen 2020; 35:1533317520960873. [PMID: 32969239 PMCID: PMC10623922 DOI: 10.1177/1533317520960873] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2024]
Abstract
Stress responses are essential for survival, but become detrimental to health and cognition with chronic activation. Chronic hypothalamic-pituitary-adrenal axis release of glucocorticoids induces hypothalamic-pituitary-adrenal axis dysfunction and neuronal loss, decreases learning and memory, and modifies glucocorticoid receptor/mineralocorticoid receptor expression. Elderly who report increased stress are nearly 3 times more likely to develop Alzheimer's disease, have decreased global cognition and faster cognitive decline than those reporting no stress. Patients with mild cognitive impairment are more sensitive to stress compared to healthy elderly and those with Alzheimer's disease. Stress may also transduce neurodegeneration via the gut microbiome. Coping styles determine hippocampal mineralocorticoid receptor expression in mice, indicating that coping modifies cortisol's effect on the brain. Identifying neuroprotective coping strategies that lessen the burden of stress may prevent or slow cognitive decline. Treatments and education designed to reduce stress should be recognized as neuroprotective.
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Zhang J, Yang Y, Liu W, Schlenk D, Liu J. Glucocorticoid and mineralocorticoid receptors and corticosteroid homeostasis are potential targets for endocrine-disrupting chemicals. ENVIRONMENT INTERNATIONAL 2019; 133:105133. [PMID: 31520960 DOI: 10.1016/j.envint.2019.105133] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/19/2019] [Accepted: 08/26/2019] [Indexed: 05/16/2023]
Abstract
Endocrine-disrupting chemicals (EDCs) have received significant concern, since they ubiquitously exist in the environment and are able to induce adverse health effects on human and wildlife. Increasing evidence shows that the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR), members of the steroid receptor subfamily, are potential targets for EDCs. GR and MR mediate the actions of glucocorticoids and mineralocorticoids, respectively, which are two main classes of corticosteroids involved in many physiological processes. The effects of EDCs on the homeostasis of these two classes of corticosteroids have also gained more attention recently. This review summarized the effects of environmental GR/MR ligands on receptor activity, and disruption of corticosteroid homeostasis. More than 130 chemicals classified into 7 main categories were reviewed, including metals, metalloids, pesticides, bisphenol analogues, flame retardants, other industrial chemicals and pharmaceuticals. The mechanisms by which EDCs interfere with GR/MR activity are primarily involved in ligand-receptor binding, nuclear translocation of the receptor complex, DNA-receptor binding, and changes in the expression of endogenous GR/MR genes. Besides directly interfering with receptors, enzyme-catalyzed synthesis and prereceptor regulation pathways of corticosteroids are also important targets for EDCs. The collected evidence suggests that corticosteroids and their receptors should be considered as potential targets for safety assessment of EDCs. The recognition of relevant xenobiotics and their underlying mechanisms of action is still a challenge in this emerging field of research.
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Affiliation(s)
- Jianyun Zhang
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Department of Public Health, School of Medicine, Hangzhou Normal University, Hangzhou 310036, China
| | - Ye Yang
- Institute of Hygiene, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Daniel Schlenk
- Department of Environmental Sciences, University of California, Riverside, 900 University Avenue, Riverside, CA 92521, United States
| | - Jing Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
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'Central' Actions of Corticosteroid Signaling Suggested by Constitutive Knockout of Corticosteroid Receptors in Small Fish. Nutrients 2019; 11:nu11030611. [PMID: 30871191 PMCID: PMC6470806 DOI: 10.3390/nu11030611] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 03/02/2019] [Accepted: 03/11/2019] [Indexed: 01/24/2023] Open
Abstract
This review highlights recent studies of the functional implications of corticosteroids in some important behaviors of model fish, which are also relevant to human nutrition homeostasis. The primary actions of corticosteroids are mediated by glucocorticoid receptor (GR) and mineralocorticoid receptor (MR), which are transcription factors. Zebrafish and medaka models of GR- and MR-knockout are the first constitutive corticosteroid receptor-knockout animals that are viable in adulthood. Similar receptor knockouts in mice are lethal. In this review, we describe the physiological and behavioral changes following disruption of the corticosteroid receptors in these models. The GR null model has peripheral changes in nutrition metabolism that do not occur in a mutant harboring a point mutation in the GR DNA-binding domain. This suggests that these are not “intrinsic” activities of GR. On the other hand, we propose that integration of visual responses and brain behavior by corticosteroid receptors is a possible “intrinsic”/principal function potentially conserved in vertebrates.
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Sakamoto T, Hyodo S, Takagi W. A possible principal function of corticosteroid signaling that is conserved in vertebrate evolution: Lessons from receptor-knockout small fish. J Steroid Biochem Mol Biol 2018; 184:57-61. [PMID: 29481854 DOI: 10.1016/j.jsbmb.2018.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 02/12/2018] [Accepted: 02/20/2018] [Indexed: 11/16/2022]
Abstract
Corticosteroid receptors are critical for homeostasis maintenance, but understanding of the principal roles of the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) throughout vertebrates is limited. Lines of constitutive GR-knockout zebrafish and MR-knockout medaka have recently been generated as the first adult-viable corticosteroid receptor-knockout animals, in contrast to the lethality of these receptor knockouts in mice. Here, we describe behavioral and physiological modifications following disruption of corticosteroid receptor function in these animal models. We suggest these data point toward a potentially conserved function of corticosteroid receptors in integrating brain-behavior and visual responses in vertebrates. Finally, we discuss how future work in cartilaginous fishes (Chondrichthyes) will further advance understanding of the unity and diversity of corticosteroid receptor function, since distinct orthologs of GR and MR derived from an ancestral corticoid receptor appear in these basal jawed vertebrates.
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Affiliation(s)
- Tatsuya Sakamoto
- Ushimado Marine Institute, Faculty of Science, Okayama University, 130-17, Kashino, Ushimado, Setouchi 701-4303, Japan.
| | - Susumu Hyodo
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan
| | - Wataru Takagi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba 277-8564, Japan
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9
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Qiao H, Wang N, Yan J. [Role of the central nucleus of the amygdala in regulating the nongenomic effect of aldosterone on sodium intake in rat nucleus tractus solitarius]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2018; 38:1159-1164. [PMID: 30377123 DOI: 10.3969/j.issn.1673-4254.2018.10.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE To reveal the nongenomic effect of aldosterone on the regulation of sodium intake in the nucleus tractus solitarius (NTS) and the role of central nucleus of the amygdala (CeA) in regulating this effect. METHODS Adult male SD rats were divided into four groups and underwent operations to induce bilateral CeA electrolytic lesions (400 μA, 25 s; n=28), bilateral sham CeA lesions (n=28), unilateral CeA lesions (n=28), or unilateral sham CeA lesions (n=26). After 3 days of recovery, the rats received implantation of a stainless steel 23-gauge cannula wih two tubes into the NTS followed by a recovery period of 7 days. The rats in each group were then divided into two subgroups for microinjection of aldosterone (50 ng/μL) or control solution in the NTS, and the cumulative intake within 30 min of 0.3 mol/L NaCl solution was recorded for each rat. RESULTS Bilateral CeA lesions (3 days) eliminated the increased 0.3 mol/L NaCl intake induced by aldosterone microinjected into the NTS (0.3±0.04 mL in CeA lesion group vs 1.3±0.3 mL in sham lesion group). Unilateral CeA lesion (3 days) reduced aldosterone-induced increase of NaCl intake in the first 15 min (P < 0.05) but not in 15-30 min (P > 0.05). In rats with sham lesions, aldosterone (50 ng/μL) still induced a significant increase in NaCl intake[1.3±0.3 mL vs 0.25±0.02 mL in the control group; F (3, 224)=24.0, P < 0.05]. CONCLUSIONS The regulation of sodium intake by aldosterone is subjected to descending facilitatory modulation by the bilateral CeA, and CeA integrity is essential for aldosterone to execute the nongenomic effect in regulating rapid sodium intake.
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Affiliation(s)
- Hu Qiao
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.,Department of Physiology and Pathophysiology; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China
| | - Nan Wang
- Department of Physiology and Pathophysiology; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China
| | - Jianqun Yan
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, College of Stomatology, Xi'an Jiaotong University, Xi'an 710004, China.,Department of Physiology and Pathophysiology; Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China
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10
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Zhang J, Huang X, Liu H, Liu W, Liu J. Novel Pathways of Endocrine Disruption Through Pesticides Interference With Human Mineralocorticoid Receptors. Toxicol Sci 2017; 162:53-63. [DOI: 10.1093/toxsci/kfx244] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Jianyun Zhang
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health
| | - Xin Huang
- Research Center for Air Pollution and Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Hongling Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China
| | - Weiping Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health
| | - Jing Liu
- MOE Key Laboratory of Environmental Remediation and Ecosystem Health
- Research Center for Air Pollution and Health, Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
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11
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Kanatsou S, Karst H, Kortesidou D, van den Akker RA, den Blaauwen J, Harris AP, Seckl JR, Krugers HJ, Joels M. Overexpression of Mineralocorticoid Receptors in the Mouse Forebrain Partly Alleviates the Effects of Chronic Early Life Stress on Spatial Memory, Neurogenesis and Synaptic Function in the Dentate Gyrus. Front Cell Neurosci 2017; 11:132. [PMID: 28611594 PMCID: PMC5447008 DOI: 10.3389/fncel.2017.00132] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 04/19/2017] [Indexed: 11/13/2022] Open
Abstract
Evidence from human studies suggests that high expression of brain mineralocorticoid receptors (MR) may promote resilience against negative consequences of stress exposure, including childhood trauma. We examined, in mice, whether brain MR overexpression can alleviate the effects of chronic early life stress (ELS) on contextual memory formation under low and high stress conditions, and neurogenesis and synaptic function of dentate gyrus granular cells. Male mice were exposed to ELS by housing the dam with limited nesting and bedding material from postnatal day (PND) 2 to 9. We investigated the moderating role of MRs by using forebrain-specific transgenic MR overexpression (MR-tg) mice. Low-stress contextual (i.e., object relocation) memory formation was hampered by ELS in wildtype but not MR-tg mice. Anxiety like behavior and high-stress contextual (i.e., fear) memory formation were unaffected by ELS and/or MR expression level. At the cellular level, an interaction effect was observed between ELS and MR overexpression on the number of doublecortin-positive cells, with a significant difference between the wildtype ELS and MR-tg ELS groups. No interaction was found regarding Ki-67 and BrdU staining. A significant interaction between ELS and MR expression was further observed with regard to mEPSCs and mIPSC frequency. The ratio of evoked EPSC/IPSC or NMDA/AMPA responses was unaffected. Overall, these results suggest that ELS affects contextual memory formation under low stress conditions as well as neurogenesis and synaptic transmission in dentate granule cells, an effect that can be alleviated by MR-overexpression.
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Affiliation(s)
- Sofia Kanatsou
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, Netherlands.,Swammerdam Institute for Life Sciences - Center for Neuroscience, University of AmsterdamAmsterdam, Netherlands
| | - Henk Karst
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, Netherlands
| | - Despoina Kortesidou
- Swammerdam Institute for Life Sciences - Center for Neuroscience, University of AmsterdamAmsterdam, Netherlands
| | - Rachelle A van den Akker
- Swammerdam Institute for Life Sciences - Center for Neuroscience, University of AmsterdamAmsterdam, Netherlands
| | - Jan den Blaauwen
- Swammerdam Institute for Life Sciences - Center for Neuroscience, University of AmsterdamAmsterdam, Netherlands
| | - Anjanette P Harris
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of EdinburghEdinburgh, United Kingdom
| | - Jonathan R Seckl
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of EdinburghEdinburgh, United Kingdom
| | - Harm J Krugers
- Swammerdam Institute for Life Sciences - Center for Neuroscience, University of AmsterdamAmsterdam, Netherlands
| | - Marian Joels
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, Netherlands.,University of Groningen, University Medical Center GroningenGroningen, Netherlands
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12
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Qiao H, Hu B, Zhou H, Yan J, Jia R, Lu B, Sun B, Luo X, Fan Y, Wang N. Aldosterone induces rapid sodium intake by a nongenomic mechanism in the nucleus tractus solitarius. Sci Rep 2016; 6:38631. [PMID: 27934887 PMCID: PMC5146675 DOI: 10.1038/srep38631] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 11/11/2016] [Indexed: 01/27/2023] Open
Abstract
The purpose of this study was to determine whether aldosterone has a rapid action in the nucleus tractus solitarius (NTS) that increases sodium intake, and to examine whether this effect of aldosterone, if present, is mediated by G protein-coupled estrogen receptor (GPER). Adult male Sprague-Dawley rats with a stainless-steel cannula in the NTS were used. Aldosterone was injected into the NTS at the doses of 1, 5, 10 and 20 ng 0.1 μl−1. A rapid dose-related increase of 0.3 M NaCl intake was induced within 30 min and this increase was not suppressed by the mineralocorticoid receptor (MR) antagonist spironolactone (10 ng 0.1 μl−1). Water intake was not affected by aldosterone. The GPER agonist G-1 produced a parallel and significant increase in sodium intake, while pre-treatment with GPER antagonist G15 (10 ng 0.1 μl−1) blocked the G-1 or aldosterone-induced rapid sodium intake. In addition, sodium intake induced by sodium depletion or low-sodium diet fell within 30 min after injection into the NTS of the MR antagonist spironolactone, while G15 had no effect. Our results confirm previous reports, and support the hypothesis that aldosterone evokes rapid sodium intake through a non-genomic mechanism involving GPER in NTS.
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Affiliation(s)
- Hu Qiao
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710000, P.R. China.,Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China.,Department of Orthodontics, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710000, P.R. China
| | - Bo Hu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Hong Zhou
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710000, P.R. China.,Department of Orthodontics, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710000, P.R. China
| | - Jianqun Yan
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, Xi'an Jiaotong University College of Stomatology, 98# Xiwu Road, Xi'an, Shaanxi 710000, P.R. China.,Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Ru Jia
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Bo Lu
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Bo Sun
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Xiao Luo
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Yuanyuan Fan
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
| | - Nan Wang
- Department of Physiology and Pathophysiology, Xi'an Jiaotong University School of Basic Medical Science, 76# W. Yanta Road, Xi'an, Shaanxi 710061, P.R. China
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Principal function of mineralocorticoid signaling suggested by constitutive knockout of the mineralocorticoid receptor in medaka fish. Sci Rep 2016; 6:37991. [PMID: 27897263 PMCID: PMC5126551 DOI: 10.1038/srep37991] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 11/03/2016] [Indexed: 01/10/2023] Open
Abstract
As in osmoregulation, mineralocorticoid signaling is implicated in the control of brain-behavior actions. Nevertheless, the understanding of this role is limited, partly due to the mortality of mineralocorticoid receptor (MR)-knockout (KO) mice due to impaired Na+ reabsorption. In teleost fish, a distinct mineralocorticoid system has only been identified recently. Here, we generated a constitutive MR-KO medaka as the first adult-viable MR-KO animal, since MR expression is modest in osmoregulatory organs but high in the brain of adult medaka as for most teleosts. Hyper- and hypo-osmoregulation were normal in MR-KO medaka. When we studied the behavioral phenotypes based on the central MR localization, however, MR-KO medaka failed to track moving dots despite having an increase in acceleration of swimming. These findings reinforce previous results showing a minor role for mineralocorticoid signaling in fish osmoregulation, and provide the first convincing evidence that MR is required for normal locomotor activity in response to visual motion stimuli, but not for the recognition of these stimuli per se. We suggest that MR potentially integrates brain-behavioral and visual responses, which might be a conserved function of mineralocorticoid signaling through vertebrates. Importantly, this fish model allows for the possible identification of novel aspects of mineralocorticoid signaling.
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Abstract
The first mineralocorticoid receptor (MR) antagonist, spironolactone, was developed almost 60 years ago to treat primary aldosteronism and pathological edema. Its use waned in part because of its lack of selectivity. Subsequently, knowledge of the scope of MR function was expanded along with clinical evidence of the therapeutic importance of MR antagonists to prevent the ravages of inappropriate MR activation. Forty-two years elapsed between the first and MR-selective second generation of MR antagonists. Fifteen years later, despite serious shortcomings of the existing antagonists, a third-generation antagonist has yet to be marketed. Progress has been slowed by the lack of appreciation of the large variety of cell types that express the MR and its diverse cell-type-specific actions, and also its unique complex interaction actions at the molecular level. New MR antagonists should preferentially target the inflammatory and fibrotic effects of MR and perhaps its excitatory effects on sympathetic nervous system, but not the renal tubular epithelium or neurons of the cortex and hippocampus. This review briefly describes efforts to develop a third-generation MR antagonist and why fourth generation antagonists and selective agonists based on structural determinants of tissue and ligand-specific MR activation should be contemplated.
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Piber D, Schultebraucks K, Mueller SC, Deuter CE, Wingenfeld K, Otte C. Mineralocorticoid receptor stimulation effects on spatial memory in healthy young adults: A study using the virtual Morris Water Maze task. Neurobiol Learn Mem 2016; 136:139-146. [PMID: 27725248 DOI: 10.1016/j.nlm.2016.10.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 09/10/2016] [Accepted: 10/06/2016] [Indexed: 01/18/2023]
Abstract
OBJECTIVES Stress hormones such as cortisol are known to influence a wide range of cognitive functions, including hippocampal based spatial memory. In the brain, cortisol acts via two different receptors: the glucocorticoid (GR) and the mineralocorticoid receptor (MR). As the MR has a high density in the hippocampus, we examined the effects of pharmacological MR stimulation on spatial memory. METHODS Eighty healthy participants (40 women, 40 men, mean age=23.9years±SD=3.3) completed the virtual Morris Water Maze (vMWM) task to test spatial encoding and spatial memory retrieval after receiving 0.4mg fludrocortisone, a MR agonist, or placebo. RESULTS There was no effect of MR stimulation on spatial encoding during the vMWM task. However, participants who received fludrocortisone exhibited improved spatial memory retrieval performance. There was neither a main effect of sex nor a sex-by-treatment interaction. CONCLUSION In young healthy participants, MR stimulation improved hippocampal based spatial memory retrieval in a virtual Morris Water Maze task. Our study not only confirms the importance of MR function in spatial memory, but suggests beneficial effects of acute MR stimulation on spatial memory retrieval in humans.
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Affiliation(s)
- Dominique Piber
- Department of Psychiatry and Psychotherapy, Charité University Hospital Berlin, Campus Benjamin Franklin, Berlin, Germany.
| | - Katharina Schultebraucks
- Department of Psychiatry and Psychotherapy, Charité University Hospital Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Sven C Mueller
- Department of Experimental Clinical and Health Psychology, Ghent University, Ghent, Belgium
| | - Christian Eric Deuter
- Department of Psychiatry and Psychotherapy, Charité University Hospital Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Katja Wingenfeld
- Department of Psychiatry and Psychotherapy, Charité University Hospital Berlin, Campus Benjamin Franklin, Berlin, Germany
| | - Christian Otte
- Department of Psychiatry and Psychotherapy, Charité University Hospital Berlin, Campus Benjamin Franklin, Berlin, Germany
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Faraji J, Soltanpour N, Moeeini R, Hosseini SA, Pakdel S, Moharrerie A, Arjang K, Soltanpour N, Metz GA. Regional vulnerability of the hippocampus to repeated motor activity deprivation. Behav Brain Res 2016; 301:178-89. [DOI: 10.1016/j.bbr.2015.12.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 11/11/2015] [Accepted: 12/18/2015] [Indexed: 12/12/2022]
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17
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Behavioural changes in dogs treated with corticosteroids. Physiol Behav 2015; 151:609-16. [PMID: 26344646 DOI: 10.1016/j.physbeh.2015.08.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Revised: 08/30/2015] [Accepted: 08/31/2015] [Indexed: 11/22/2022]
Abstract
In human medicine, psychiatric side effects among patients on corticosteroid therapy are widely reported, but this appears to have been largely overlooked in the animal literature despite glucocorticoids being widely used in veterinary medicine. Therefore the aim of the current study was to identify possible psycho-behavioural changes in dogs treated with corticosteroids. Two different methodologies were used. Firstly, dog owners were asked to fill a 12 item questionnaire aimed at further validating the initial results of a previous survey relating to changes seen when their dog was receiving corticosteroid treatment. In a second study, a population of dogs undertook behavioural tests aimed at objectively identifying changes when receiving corticosteroid therapy. In the first study, a sample of owners whose dogs were receiving treatment for dermatological, orthopaedic or other conditions evaluated their dogs' behaviour on and off therapy, using a seven point scale. The survey was completed by 44 dog owners with dogs receiving treatment with a range of corticosteroid preparations (mainly prednisolone and methylprednisolone) and 54 dog owners with dogs receiving treatment with other drugs, mainly antibiotics and non-steroidal anti-inflammatory drugs. Dogs under corticosteroid treatment were reported to be significantly less playful, more nervous/restless, more fearful/less confident, more aggressive in the presence of food, more prone to barking, more prone to startle, more prone to reacting aggressively when disturbed, and more prone to avoiding people or unusual situations. In the second study, eleven “treatment” dogs were tested both before and during corticosteroid treatment with either methyl-prednisolone or prednisolone to assess their sensitivity to a potentially aversive sound stimulus. Eleven control dogs were also tested at the same time intervals in the same environment. Dogs were exposed to a brief dog growl while they explored bowls containing food and their behaviour was video recorded. Treatment dogs were found to investigate the area in the vicinity of the bowls for significantly less time and to eat significantly fewer pieces of food when on corticosteroids, compared to control dogs, after hearing the growl. These results provide the first empirical evidence of possible adverse psycho-behavioural side effects in a veterinary clinical setting following the use of corticosteroids, and suggest the need for concomitant behavioural advice when these drugs are used in general veterinary practise to avoid the risks associated with these changes.
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Kanatsou S, Kuil LE, Arp M, Oitzl MS, Harris AP, Seckl JR, Krugers HJ, Joels M. Overexpression of mineralocorticoid receptors does not affect memory and anxiety-like behavior in female mice. Front Behav Neurosci 2015; 9:182. [PMID: 26236208 PMCID: PMC4501076 DOI: 10.3389/fnbeh.2015.00182] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Accepted: 06/29/2015] [Indexed: 11/13/2022] Open
Abstract
Mineralocorticoid receptors (MRs) have been implicated in behavioral adaptation and learning and memory. Since-at least in humans-MR function seems to be sex-dependent, we examined the behavioral relevance of MR in female mice exhibiting transgenic MR overexpression in the forebrain. Transgenic MR overexpression did not affect contextual fear memory or cued fear learning and memory. Moreover, MR overexpressing and control mice discriminated equally well between fear responses in a combined cue and context fear conditioning paradigm. Also context-memory in an object recognition task was unaffected in MR overexpressing mice. We conclude that MR overexpression in female animals does not affect fear conditioned responses and object recognition memory.
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Affiliation(s)
- Sofia Kanatsou
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
| | - Laura E Kuil
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Marit Arp
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Melly S Oitzl
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Anjanette P Harris
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of Edinburgh Edinburgh, UK
| | - Jonathan R Seckl
- Endocrinology Unit, Centre for Cardiovascular Science, Queen's Medical Research Institute, The University of Edinburgh Edinburgh, UK
| | - Harm J Krugers
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam Amsterdam, Netherlands
| | - Marian Joels
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht Utrecht, Netherlands
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Rotenstein LS, Sheridan M, Garg R, Adler GK. Effect of mineralocorticoid receptor blockade on hippocampal-dependent memory in adults with obesity. Obesity (Silver Spring) 2015; 23:1136-42. [PMID: 25959271 PMCID: PMC4446234 DOI: 10.1002/oby.21104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Accepted: 02/28/2015] [Indexed: 01/05/2023]
Abstract
OBJECTIVE The hippocampus is crucial for paired-associate learning. Obesity is associated with increased mineralocorticoid receptor (MR) activity in peripheral and possibly central tissues, decreased hippocampal size in humans, and impaired hippocampal learning in rodents. The MR is expressed in hippocampal neurons, and MR blockade improves hippocampal learning in obese animals. The goal of the study was to determine whether MR blockade would modulate paired-associate learning in men and women with obesity. METHODS Men and women ages 20-61 years with BMI between 30-45 kg/m(2) were randomly assigned to placebo (n = 11; 7 women) or 50 mg spironolactone daily (n = 12; 7 women) for six weeks. At baseline and post-treatment, subjects underwent a clinical and hormonal evaluation. They also underwent a computerized task that assesses paired-associate learning and has been shown by functional magnetic resonance imaging to activate the hippocampus. RESULTS In an ANCOVA model that adjusted for baseline paired-associate learning, age, and race, spironolactone treatment was associated with a significant (P = 0.043) improvement in hippocampal memory as compared to placebo treatment. CONCLUSIONS Our findings demonstrate, for the first time, that blocking MR with chronic, low-dose spironolactone treatment improves paired-associate learning in individuals with obesity, suggesting that MR activation contributes to hippocampal memory modulation in humans.
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Affiliation(s)
| | - Margaret Sheridan
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Pediatrics, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rajesh Garg
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Gail K Adler
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Wang T, Hu X, Liang S, Li W, Wu X, Wang L, Jin F. Lactobacillus fermentum NS9 restores the antibiotic induced physiological and psychological abnormalities in rats. Benef Microbes 2015; 6:707-17. [PMID: 25869281 DOI: 10.3920/bm2014.0177] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Gut microbiota play a vital role in maintaining the health of the host. Many factors affect gut microbiota; application of broad range antibiotics disturb microbiota, while probiotic application protects the microbiota. To investigate how probiotics alter the physiological and psychological changes induced by antibiotics, we tested the performance of ampicillin-treated rats in the presence or absence of Lactobacillus fermentum strain NS9, in elevated plus maze and Morris water maze. The results showed that NS9 normalised the composition of gut microbiota and alleviated the ampicillin-induced inflammation in the colon. The levels of the mineralocorticoid and N-methyl-D-aspartate receptors were also elevated in the hippocampus of the ampillicin+NS9 treated group. NS9 administration also reduced the anxiety-like behaviour and alleviated the ampicillin-induced impairment in memory retention. These findings suggest that NS9 is beneficial to the host, because it restores the physiological and psychological abnormalities induced by ampicillin. Our results highlight how gut contents regulate the brain, and shed light on the clinical applications of probiotics to treat the side effect of antibiotics and mental disorders.
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Affiliation(s)
- T Wang
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
| | - X Hu
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
| | - S Liang
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
| | - W Li
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
| | - X Wu
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
| | - L Wang
- 2 Institute of Ageing Research, Hangzhou Normal University, Building D, Science and Technology Park, 1378 Wenyi West Road, Hangzhou, Zhejiang 311121, China P.R
| | - F Jin
- 1 Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 16 Lincui Road, Chaoyang District, Beijing 100101, China P.R
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Abstract
The primary adrenal cortical steroid hormones, aldosterone, and the glucocorticoids cortisol and corticosterone, act through the structurally similar mineralocorticoid (MR) and glucocorticoid receptors (GRs). Aldosterone is crucial for fluid, electrolyte, and hemodynamic homeostasis and tissue repair; the significantly more abundant glucocorticoids are indispensable for energy homeostasis, appropriate responses to stress, and limiting inflammation. Steroid receptors initiate gene transcription for proteins that effect their actions as well as rapid non-genomic effects through classical cell signaling pathways. GR and MR are expressed in many tissues types, often in the same cells, where they interact at molecular and functional levels, at times in synergy, others in opposition. Thus the appropriate balance of MR and GR activation is crucial for homeostasis. MR has the same binding affinity for aldosterone, cortisol, and corticosterone. Glucocorticoids activate MR in most tissues at basal levels and GR at stress levels. Inactivation of cortisol and corticosterone by 11β-HSD2 allows aldosterone to activate MR within aldosterone target cells and limits activation of the GR. Under most conditions, 11β-HSD1 acts as a reductase and activates cortisol/corticosterone, amplifying circulating levels. 11β-HSD1 and MR antagonists mitigate inappropriate activation of MR under conditions of oxidative stress that contributes to the pathophysiology of the cardiometabolic syndrome; however, MR antagonists decrease normal MR/GR functional interactions, a particular concern for neurons mediating cognition, memory, and affect.
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Affiliation(s)
- Elise Gomez-Sanchez
- G.V.(Sonny) Montgomery V.A. Medical Center and Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi
| | - Celso E. Gomez-Sanchez
- G.V.(Sonny) Montgomery V.A. Medical Center and Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi
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22
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Alexander JL, Sommer BR, Dennerstein L, Grigorova M, Neylan T, Kotz K, Richardson G, Rosenbaum R. Role of psychiatric comorbidity on cognitive function during and after the menopausal transition. Expert Rev Neurother 2014; 7:S157-80. [DOI: 10.1586/14737175.7.11s.s157] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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23
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Goggin SL, Caldwell KK, Cunningham LA, Allan AM. Prenatal alcohol exposure alters p35, CDK5 and GSK3β in the medial frontal cortex and hippocampus of adolescent mice. Toxicol Rep 2014; 1:544-553. [PMID: 25243109 PMCID: PMC4166584 DOI: 10.1016/j.toxrep.2014.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Fetal alcohol spectrum disorders (FASDs) are the number one cause of preventable mental retardation. An estimated 2-5% of children are diagnosed as having a FASD. While it is known that children prenatally exposed to alcohol experience cognitive deficits and a higher incidence of psychiatric illness later in life, the pathways underlying these abnormalities remain uncertain. GSK3β and CDK5 are protein kinases that are converging points for a vast number of signaling cascades, including those controlling cellular processes critical to learning and memory. We investigated whether levels of GSK3β and CDK5 are affected by moderate prenatal alcohol exposure (PAE), specifically in the hippocampus and medial frontal cortex of the adolescent mouse. In the present work we utilized immunoblotting techniques to demonstrate that moderate PAE increased hippocampal p35 and β-catenin, and decreased total levels of GSK3β, while increasing GSK3β Ser9 and Tyr216 phosphorylation. Interestingly, different alterations were seen in the medial frontal cortex where p35 and CDK5 were decreased and increased total GSK3β was accompanied by reduced Tyr216 of the enzyme. These results suggest that kinase dysregulation during adolescence might be an important contributing factor to the effects of PAE on hippocampal and medial frontal cortical functioning; and by extension, that global modulation of these kinases may produce differing effects depending on brain region.
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Affiliation(s)
- Samantha L Goggin
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Kevin K Caldwell
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Lee Anna Cunningham
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
| | - Andrea M Allan
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States
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Differential contribution of mineralocorticoid and glucocorticoid receptors to memory formation during sleep. Psychoneuroendocrinology 2013; 38:2962-72. [PMID: 24035099 DOI: 10.1016/j.psyneuen.2013.08.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/31/2013] [Accepted: 08/21/2013] [Indexed: 11/21/2022]
Abstract
Corticosteroids are known to modulate the consolidation of memories during sleep, specifically in the hippocampus-dependent declarative memory system. However, effects of the major human corticosteroid cortisol are conveyed via two different receptors, i.e., mineralocorticoid (MRs) and glucocorticoid receptors (GRs) whose specific contributions to memory consolidation are unclear. Whereas a shift in the balance between MR and GR activation toward predominant GR activation has been found to impair sleep-dependent consolidation of declarative memories, the effect of predominant MR activation is not well characterized. Here, we examined differential corticosteroid receptor contributions to memory consolidation during post-learning sleep in two placebo-controlled double-blind studies in humans, by comparing the effects of the selective MR agonist fludrocortisone (0.2 mg, orally, Study 1) and of hydrocortisone (22 mg, intravenously, Study 2) with strong binding affinity to both MR and GR. We hypothesized increased activation of MRs during sleep to enhance declarative memory consolidation, but the joint MR/GR activation to impair it. Participants (16 men in each study) learned a declarative (word pair associates) and a procedural task (mirror tracing) before a 7-h period of nocturnal retention sleep, with the substances administered before sleep (Study 1) and during sleep (Study 2), respectively. As hypothesized, retention of word pairs, but not of mirror tracing skill, was selectively enhanced by the MR agonist fludrocortisone. An impairing effect of hydrocortisone on word pair retention remained non-significant possibly reflecting that hydrocortisone administration failed to establish robust predominance of GR activation. Our results show that predominant MR activation benefits declarative memory consolidation presumably by enhancing the sleep-dependent reactivation of hippocampal memories and resultant synaptic plastic processes. The effect is counteracted by additional GR activation. Insufficient MR activation, like GR overactivation, might be a factor contributing to memory impairment in pathological conditions.
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Rimmele U, Besedovsky L, Lange T, Born J. Blocking mineralocorticoid receptors impairs, blocking glucocorticoid receptors enhances memory retrieval in humans. Neuropsychopharmacology 2013; 38:884-94. [PMID: 23303058 PMCID: PMC3671995 DOI: 10.1038/npp.2012.254] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 11/23/2012] [Accepted: 11/26/2012] [Indexed: 01/03/2023]
Abstract
Memory retrieval is impaired at very low as well as very high cortisol levels, but not at intermediate levels. This inverted-U-shaped relationship between cortisol levels and memory retrieval may originate from different roles of the mineralocorticoid (MR) and glucocorticoid receptor (GR) that bind cortisol with distinctly different affinity. Here, we examined the role of MRs and GRs in human memory retrieval using specific receptor antagonists. In two double-blind within-subject, cross-over designed studies, young healthy men were asked to retrieve emotional and neutral texts and pictures (learnt 3 days earlier) between 0745 and 0915 hours in the morning, either after administration of 400 mg of the MR blocker spironolactone vs placebo (200 mg at 2300 hours and 200 mg at 0400 hours, Study I) or after administration of the GR blocker mifepristone vs placebo (200 mg at 2300 hours, Study II). Blockade of MRs impaired free recall of both texts and pictures particularly for emotional material. In contrast, blockade of GRs resulted in better memory retrieval for pictures, with the effect being more pronounced for neutral than emotional materials. These findings indicate indeed opposing roles of MRs and GRs in memory retrieval, with optimal retrieval at intermediate cortisol levels likely mediated by high MR but concurrently low GR activation.
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Affiliation(s)
- Ulrike Rimmele
- Department of Neurosciences, University of Geneva, Geneva, Switzerland.
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26
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Zhang L, Zhang J, Sun H, Zhu H, Liu H, Yang Y. An enriched environment elevates corticosteroid receptor levels in the hippocampus and restores cognitive function in a rat model of chronic cerebral hypoperfusion. Pharmacol Biochem Behav 2013; 103:693-700. [PMID: 23290935 DOI: 10.1016/j.pbb.2012.12.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 11/16/2012] [Accepted: 12/22/2012] [Indexed: 10/27/2022]
Abstract
An enriched environment (EE) is beneficial for modifying certain behaviors, particularly those involving complex cognitive functions. In models of chronic cerebral hypoperfusion (CCH), the ability of an EE to restore cognition depends on hippocampal synaptic plasticity and brain-derived neurotrophic factor. The mechanisms for this effect have not, however, been adequately studied. Here we investigated the effects of CCH and an EE on serum corticosteroid concentrations and the levels of the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) in the hippocampus. Rats were randomly divided into four treatment groups that received either permanent bilateral ligation of the common carotid arteries or sham surgery. Following this procedure, rats were exposed to 4 weeks of either an EE or standard housing. After the environmental intervention, their spatial learning and memory abilities were examined using the Morris water maze. In addition, the levels of MR and GR proteins in the hippocampus were determined. CCH impaired spatial cognitive function in rats, and exposure to an EE diminished these spatial learning and memory deficits. CCH also reduced the levels of MR and GR proteins in the hippocampus, but an EE restored the levels. Our results demonstrate that EE exposure restores cognitive impairments induced by CCH and up-regulates MR and GR expression. As such, MR and GR may contribute to the diminished effects of an EE in rats with CCH.
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Affiliation(s)
- Lei Zhang
- Department of Neurology and Neuropsychological Research Center, Zhongnan Hospital, Wuhan University, Donghu Road 169#, Wuhan 430071, Hubei, China
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Yau JLW, Seckl JR. Local amplification of glucocorticoids in the aging brain and impaired spatial memory. Front Aging Neurosci 2012; 4:24. [PMID: 22952463 PMCID: PMC3430012 DOI: 10.3389/fnagi.2012.00024] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 08/02/2012] [Indexed: 12/24/2022] Open
Abstract
The hippocampus is a prime target for glucocorticoids (GCs) and a brain structure particularly vulnerable to aging. Prolonged exposure to excess GCs compromises hippocampal electrophysiology, structure, and function. Blood GC levels tend to increase with aging and correlate with impaired spatial memory in aging rodents and humans. The magnitude of GC action within tissues depends not only on levels of steroid hormone that enter the cells from the periphery and the density of intracellular receptors but also on the local metabolism of GCs by 11β-hydroxysteroid dehydrogenases (11β-HSD). The predominant isozyme in the adult brain, 11β-HSD1, locally regenerates active GCs from inert 11-keto forms thus amplifying GC levels within specific target cells including in the hippocampus and cortex. Aging associates with elevated hippocampal and neocortical 11β-HSD1 and impaired spatial learning while deficiency of 11β-HSD1 in knockout (KO) mice prevents the emergence of cognitive decline with age. Furthermore, short-term pharmacological inhibition of 11β-HSD1 in already aged mice reverses spatial memory impairments. Here, we review research findings that support a key role for GCs with special emphasis on their intracellular regulation by 11β-HSD1 in the emergence of spatial memory deficits with aging, and discuss the use of 11β-HSD1 inhibitors as a promising novel treatment in ameliorating/improving age-related memory impairments.
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Affiliation(s)
- Joyce L W Yau
- Centre for Cognitive Ageing and Cognitive Epidemiology and Endocrinology Unit, Centre for Cardiovascular Science, The Queen's Medical Research Institute, University of Edinburgh Edinburgh, UK
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McEown K, Treit D. Mineralocorticoid receptors in the medial prefrontal cortex and hippocampus mediate rats' unconditioned fear behaviour. Horm Behav 2011; 60:581-8. [PMID: 21889941 DOI: 10.1016/j.yhbeh.2011.08.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 08/11/2011] [Accepted: 08/12/2011] [Indexed: 01/14/2023]
Abstract
Corticosterone is released from the adrenal cortex in response to stress, and binds to glucocorticosteroid receptors (GRs) and mineralocorticosteroid receptors (MRs) in the brain. Areas such as the dorsal hippocampus (DH), ventral hippocampus (VH) and medial prefrontal cortex (mPFC) all contain MRs and have been previously implicated in fear and/or memory. The purpose of the following experiments was to examine the role of these distinct populations of MRs in rats' unconditioned fear and fear memory. The MR antagonist (RU28318) was microinfused into the DH, VH, or mPFC of rats. Ten minutes later, their unconditioned fear was tested in the elevated plus-maze and the shock-probe tests, two behavioral models of rat "anxiety." Twenty-four hours later, conditioned fear of a non-electrified probe was assessed in rats re-exposed the shock-probe apparatus. Microinfusions of RU28318 into each of the three brain areas reduced unconditioned fear in the shock-probe burying test, but only microinfusions into the VH reduced unconditioned fear in the plus-maze test. RU28318 did not affect conditioned fear of the shock-probe 24hr later. MRs in all three areas of the brain mediated unconditioned fear to a punctate, painful stimulus (probe shock). However, only MRs in the ventral hippocampus seemed to mediate unconditioned fear of the more diffuse threat of open spaces (open arms of the plus maze). In spite of the known roles of the hippocampus in spatial memory and conditioned fear memory, MRs within these sites did not appear to mediate memory of the shock-probe.
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Andrade C, Shaikh SA, Narayan L, Blasey C, Belanoff J. Administration of a selective glucocorticoid antagonist attenuates electroconvulsive shock-induced retrograde amnesia. J Neural Transm (Vienna) 2011; 119:337-44. [PMID: 21922193 DOI: 10.1007/s00702-011-0712-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Accepted: 08/23/2011] [Indexed: 11/29/2022]
Abstract
Mifepristone, a glucocorticoid and progesterone receptor antagonist, has been shown to attenuate retrograde amnesia induced by repeated electroconvulsive shocks (ECS). We examined the efficacy of CORT 108297, a selective glucocorticoid antagonist, in this regard. Adult, male, Wistar rats (n = 69) received either vehicle or CORT 108297 (1 mg/kg) 2 h before each of 5 once-daily true or sham 30 mC ECS. Recall of previous exposure to a noxious stimulus in a passive avoidance (step-through) paradigm was tested 1 day after the 5-ECS course. Analyses were conducted using recall operationalized in different ways: using the absolute final latency scores; defining adequate recall as a final latency of 30 s or greater; defining perfect recall as a final latency of 180 s; and using visual, subjective assessments of animal behavior. ECS was associated with significant impairment of recall, and this impairment was significantly attenuated by CORT 108297 on all outcome measures (with the exception of the perfect recall analyses, where outcomes narrowly missed statistical significance). In conclusion, these findings strengthen previous data from our laboratory implicating glucocorticoid mechanisms in ECS-induced retrograde amnesia. We suggest that the administration of a selective glucocorticoid receptor antagonist shortly before electroconvulsive therapy (ECT) treatments may attenuate the deleterious effect of ECT-induced acute hypercortisolemia on neural mechanisms involved in learning and memory.
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Affiliation(s)
- Chittaranjan Andrade
- Department of Psychopharmacology, National Institute of Mental Health and Neurosciences, Bangalore 560 029, India.
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11beta-hydroxysteroid dehydrogenase type 1 deficiency prevents memory deficits with aging by switching from glucocorticoid receptor to mineralocorticoid receptor-mediated cognitive control. J Neurosci 2011; 31:4188-93. [PMID: 21411659 DOI: 10.1523/jneurosci.6145-10.2011] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Local brain amplification of glucocorticoids (GCs) by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) plays a pivotal role in age-related memory deficits. 11β-HSD1 deficient mice are protected from spatial memory impairments with aging, but the underlying mechanisms are unknown. To determine which brain receptors [high-affinity mineralocorticoid receptors (MRs) or low-affinity glucocorticoid receptors (GRs)] are involved, spatial memory was measured in aged 11β-HSD1(-/-) mice before and during intracerebroventricular infusion (10 d) of spironolactone (MR antagonist) or RU486 (GR antagonist). Aged C57BL/6J control mice showed impaired spatial memory in the Y-maze; this improved with GR blockade, while MR blockade had no effect. In contrast, aged 11β-HSD1(-/-) mice showed intact spatial memory that became impaired with MR blockade, but not GR blockade. Hippocampal MR and GR mRNA expression and plasma corticosterone levels were not significantly altered with spironolactone or RU486 in either genotype. These data support the notion that 11β-HSD1 deficiency in aging mice leads to lower intracellular GC concentrations in brain, particularly in the hippocampus, which activate predominantly MRs to enhance memory, while in aging C57BL/6J controls, the increased intracellular GCs saturate MRs and activate predominantly GRs, thus impairing memory, an effect reversed by GR blockade.
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Jadavji NM, Supina RD, Metz GA. Blockade of mineralocorticoid and glucocorticoid receptors reverses stress-induced motor impairments. Neuroendocrinology 2011; 94:278-90. [PMID: 22024815 DOI: 10.1159/000329988] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 05/31/2011] [Indexed: 02/04/2023]
Abstract
AIM Stress and glucocorticoids can influence movement performance and pathologies of the motor system. The classic notion assumes that the glucocorticoid receptor (GR) mediates the majority of stress-induced behavioral changes. Nevertheless, recent findings have attributed a more prominent role to the mineralocorticoid receptor (MR) in modulating behavior. The purpose of this study was to dissociate the impact of MR versus GR activation in movement and stress-associated motor disruption. METHODS Groups of male and female rats were tested in skilled reaching and open field behavior and treated peri-orally with either agonists or antagonists for MR and GR, respectively. RESULTS Selective acute activation of MR (aldosterone) and GR (dexamethasone) decreased movement success with a magnitude similar to stress-induced impairment in male and female animals. By contrast, antagonist treatment to block MR (RU-28318) or GR (Mifepristone, RU-486) prevented motor impairments caused by acute restraint stress or corticosterone treatment. Moreover, both antagonists reversed chronic stress- and glucocorticoid-induced motor impairments to values comparable to baseline levels. Higher success rates in treated animals were accompanied by improved performance of skilled limb movements. In addition, combined treatment with MR and GR antagonists had additive benefit on aim and advance towards the reaching target. CONCLUSION These observations suggest that MR or GR equally influence motor system function with partially synergistic effects. Males and females show comparable responses to MR and GR activation or blockade. The need for balanced activation of MRs and GRs in motor control requires consideration in intervention strategies to improve performance in health and disease.
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Affiliation(s)
- Nafisa M Jadavji
- Canadian Centre for Behavioural Neuroscience, University of Lethbridge, Lethbridge, AB, Canada
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Mitra R, Sapolsky RM. Gene therapy in rodent amygdala against fear disorders. Expert Opin Biol Ther 2010; 10:1289-303. [DOI: 10.1517/14712598.2010.509341] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Burman MA, Hamilton KL, Gewirtz JC. Role of corticosterone in trace and delay conditioned fear-potentiated startle in rats. Behav Neurosci 2010; 124:294-9. [PMID: 20364889 DOI: 10.1037/a0018911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Emotional events often lead to particularly strong memory formation. Corticosterone, the final product of hypothalamic-pituitary-adrenal (HPA)-axis activation, has been suggested to play a critical role in this effect. Although a great deal of work has implicated the amygdala as a necessary structure for the effects of corticosterone, other studies have suggested a critical role for the hippocampus in determining the involvement of corticosterone. The current experiments examined this question by disrupting corticosterone synthesis with administration of metyrapone (25 or 100 mg/kg) prior to training in either dorsal hippocampus-independent delay fear conditioning or dorsal hippocampus-dependent trace fear conditioning. Metyrapone administration 2 hrs prior to training significantly attenuated corticosterone secretion during training, but these effects were transient as corticosterone levels were similar to control subjects following the test session. As hypothesized, only trace fear conditioning was impaired. This suggests that only fear conditioning tasks that are dependent on the dorsal hippocampus require HPA-axis activation in order to be learned.
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Affiliation(s)
- Michael A Burman
- Department of Psychology, University of New England, Biddeford, ME 04005, USA.
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Hinkelmann K, Moritz S, Botzenhardt J, Riedesel K, Wiedemann K, Kellner M, Otte C. Cognitive impairment in major depression: association with salivary cortisol. Biol Psychiatry 2009; 66:879-85. [PMID: 19709646 DOI: 10.1016/j.biopsych.2009.06.023] [Citation(s) in RCA: 141] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2009] [Revised: 06/23/2009] [Accepted: 06/30/2009] [Indexed: 12/23/2022]
Abstract
BACKGROUND Cognitive deficits and elevated cortisol are hallmarks of depression. Cortisol acts via mineralocorticoid and glucocorticoid receptors, which have their highest density in the hippocampus, a brain area closely related to cognitive function. Several studies have separately examined cortisol secretion and cognitive deficits in depression. However, only few studies have assessed their association in the same patients producing inconclusive results. METHODS We examined 52 medication-free patients with major depression (37 women, 15 men; mean age 35 +/- 11 years; Hamilton Depression Scale mean score 27 +/- 5) and 50 healthy control subjects, matched for age, gender, and years of education. We applied several neuropsychological tests. Salivary cortisol levels were measured on the same day at 08:00, 12:00, 16:00, and 22:00 hours. RESULTS Compared with healthy subjects, patients had significantly higher cortisol levels and were impaired in verbal memory, visuospatial memory, working memory, and selective attention. In depressed patients, but not in healthy control subjects, we found a negative correlation between salivary cortisol levels (area under the curve) and hippocampus-related neuropsychological domains (verbal memory, visuospatial memory) and executive function. CONCLUSIONS Cognitive deficits, especially those closely related to hippocampus function, appear to be related to cortisol secretion in depressed patients. Elevated cortisol may downregulate mineralocorticoid and glucocorticoid receptors in the hippocampus, which could, in part, be responsible for cognitive deficits in depressed patients.
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Affiliation(s)
- Kim Hinkelmann
- Department of Psychiatry and Psychotherapy, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Mitra R, Ferguson D, Sapolsky RM. Mineralocorticoid receptor overexpression in basolateral amygdala reduces corticosterone secretion and anxiety. Biol Psychiatry 2009; 66:686-90. [PMID: 19500777 DOI: 10.1016/j.biopsych.2009.04.016] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2008] [Revised: 03/17/2009] [Accepted: 04/02/2009] [Indexed: 11/15/2022]
Abstract
BACKGROUND The amygdala plays a critical role in the development of anxiety and the regulation of stress hormone secretion. Reciprocally, stress and stress hormones can induce amygdala hypertrophy, a phenomenon related to enhanced anxiety. As such, modulating amygdaloid function can potentially reduce maladaptive features of the stress response. The amygdala contains two kind of receptor for corticosteroids, the adrenal steroid hormone released during stress: glucocorticoid receptors (GRs) and mineralocorticoid receptors (MRs). Although high-affinity MRs are heavily occupied during basal conditions, low-affinity GRs are heavily occupied only by stress levels of glucocorticoids. Prolonged and heavy occupancy of GRs tends to mediate the deleterious effects of glucocorticoids on neurons, whereas MR occupancy tends to mediate beneficial effects. METHODS In this report, we overexpress MR in neurons of adult rat basolateral amygdala, with a herpes simplex viral vector coding for two copies of MR. RESULTS Such overexpression reduced anxiety, as measured on an elevated plus-maze, and reduced the magnitude of glucocorticoid secretion after an acute stressor. CONCLUSIONS Thus, increasing MR signaling in basolateral amygdala could be valuable in management of stress disorders.
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Affiliation(s)
- Rupshi Mitra
- Department of Biology, Stanford University, Stanford, California 94305, USA.
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Martinez-Finley EJ, Ali AMS, Allan AM. Learning deficits in C57BL/6J mice following perinatal arsenic exposure: consequence of lower corticosterone receptor levels? Pharmacol Biochem Behav 2009; 94:271-7. [PMID: 19751756 DOI: 10.1016/j.pbb.2009.09.006] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 09/02/2009] [Accepted: 09/03/2009] [Indexed: 01/31/2023]
Abstract
Most studies on arsenic as a drinking water contaminant have focused on its carcinogenic potential but a few suggest that arsenic can adversely affect cognitive development. One parameter of the hypothalamic-pituitary-adrenal axis, the corticosterone receptor (CR) has been shown to be altered by arsenic. These receptors are found throughout the central nervous system, particularly in the hippocampus, an area of the brain of central importance for learning and memory. We examined the impact of perinatal exposure to 50 parts per billion (ppb) sodium arsenate on CRs and learning and memory behavior in the C57BL/6J mouse. Measurements of CRs revealed that arsenic-exposed offspring have significantly lower levels of these receptors in the nucleus than controls. Exposed offspring showed longer latency to approach a novel object than controls in an object recognition task. In the 8-way radial arm maze, arsenic offspring had a significant increase in the number of entry errors compared to controls. Results suggest that moderate exposures to perinatal arsenic can significantly reduce CR levels in the hippocampus and can have adverse effects on learning and memory behavior.
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Affiliation(s)
- Ebany J Martinez-Finley
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM 87131, United States.
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Brinks V, Berger S, Gass P, de Kloet ER, Oitzl MS. Mineralocorticoid receptors in control of emotional arousal and fear memory. Horm Behav 2009; 56:232-8. [PMID: 19447109 DOI: 10.1016/j.yhbeh.2009.05.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/19/2009] [Accepted: 05/01/2009] [Indexed: 11/22/2022]
Abstract
The stress hormone corticosterone acts via two receptor types in the brain: the mineralocorticoid (MR) and the glucocorticoid receptor (GR). Both receptors are involved in processing of stressful events. A disbalance of MR:GR functions is thought to promote stress-related disorders. Here we studied the effect of stress on emotional and cognitive behaviors in mice with forebrain-specific inactivation of the MR gene (MR(CaMKCre), 4 months old; and control littermates). MR(CaMKCre) mice responded to prior stress (5 min of restraint) with higher arousal and less locomotor activity in an exploration task. A fear conditioning paradigm allowed assessing in one experimental procedure both context- and cue-related fear. During conditioning, MR(CaMKCre) mice expressed more cue-related freezing. During memory test, contextual freezing remained potentiated, while control mice distinguished between cue (more freezing) and context episodes (less freezing) in the second memory test. At this time, plasma corticosterone levels of MR(CaMKCre) mice were 40% higher than in controls. We conclude that control of emotional arousal and adaptive behaviors is lost in the absence of forebrain MR, and thus, anxiety-related responses are and remain augmented. We propose that such a disbalance in MR:GR functions in MR(CaMKCre) mice provides the conditions for an animal model for anxiety-related disorders.
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Affiliation(s)
- V Brinks
- Division of Medical Pharmacology, LACDR/LUMC, Gorlaeus Laboratories, PO Box 9502, Leiden University, 2300 RA Leiden, The Netherlands
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Ferguson D, Sapolsky R. Overexpression of mineralocorticoid and transdominant glucocorticoid receptor blocks the impairing effects of glucocorticoids on memory. Hippocampus 2008; 18:1103-11. [DOI: 10.1002/hipo.20467] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Kellner M, Wiedemann K. Mineralocorticoid receptors in brain, in health and disease: Possibilities for new pharmacotherapy. Eur J Pharmacol 2008; 583:372-8. [DOI: 10.1016/j.ejphar.2007.07.072] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 07/20/2007] [Accepted: 07/26/2007] [Indexed: 10/22/2022]
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Ferguson D, Sapolsky R. Mineralocorticoid receptor overexpression differentially modulates specific phases of spatial and nonspatial memory. J Neurosci 2007; 27:8046-52. [PMID: 17652595 PMCID: PMC6672723 DOI: 10.1523/jneurosci.1187-07.2007] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Glucocorticoids (GCs) and stress modulate specific phases of information processing. The modulatory affects of GCs on hippocampal function are thought to be mediated by the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). The GR plays a critical role in mediating the impairing effects of GCs on hippocampal function. Conversely, activation of MR facilitates hippocampal function. The high affinity of MR for GCs suggests that the receptor protein levels play a key role in regulating the beneficial effects of MR-mediated gene transcription. Using herpes simplex vectors, we transiently increased MR levels in dentate gyrus granule cells, which in turn enhanced MR signaling. We then examined its effects on spatial and nonspatial memory consolidation and retrieval using the object placement and object recognition task. Additionally, we assessed whether an increased MR signal could block the impairing effects of high GCs on memory retrieval. Rats overexpressing MR displayed an enhancement in the consolidation of nonspatial memory relative to rats expressing green fluorescent protein and suggest the potential for gene transfer techniques for enhancing cognition during stress. Moreover, rats overexpressing MR were spared from the disruptive effects of high GCs on the retrieval of nonspatial memory. Thus, this study illustrates the critical role of MR in mediating the retrieval and consolidation of nonspatial memory.
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Affiliation(s)
- Deveroux Ferguson
- Department of Biological Sciences, Stanford University, Stanford, California 94305, USA.
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41
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Lai M, Horsburgh K, Bae SE, Carter RN, Stenvers DJ, Fowler JH, Yau JL, Gomez-Sanchez CE, Holmes MC, Kenyon CJ, Seckl JR, Macleod MR. Forebrain mineralocorticoid receptor overexpression enhances memory, reduces anxiety and attenuates neuronal loss in cerebral ischaemia. Eur J Neurosci 2007; 25:1832-42. [PMID: 17432969 DOI: 10.1111/j.1460-9568.2007.05427.x] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The nuclear mineralocorticoid receptor (MR), a high-affinity receptor for glucocorticoids, is highly expressed in the hippocampus where it underpins cognitive, behavioural and neuroendocrine regulation. Increased neuronal MR expression occurs early in the response to cellular injury in vivo and in vitro and is associated with enhanced neuronal survival. To determine whether increased neuronal MR might be causal in protecting against ischaemic damage in vivo we generated a forebrain-specific MR-overexpressing transgenic mouse (MR-Tg) under the control of the CamKII alpha promoter, and subjected mice to transient cerebral global ischaemia induced by bilateral common carotid artery occlusion for 20 min. We also separately assessed the effects of MR overexpression on hypothalamic-pituitary-adrenal (HPA) axis activity and cognitive and affective functions in noninjured animals. Our results showed that MR-Tg mice had significantly reduced neuronal death following transient cerebral global ischaemia compared to wild-type littermates. This effect was not associated with alterations in basal or poststress HPA axis function or in arterial blood pressure. MR-Tg mice also demonstrated improved spatial memory retention, reduced anxiety and altered behavioural response to novelty. The induction of neuronal MR appears to offer a protective response which has potential therapeutic implications in cerebral ischaemia and cognitive and affective disorders.
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Affiliation(s)
- Maggie Lai
- Endocrinology Unit, Centre for Cardiovascular Science, University of Edinburgh, Queen's Medical Research Institute, Edinburgh, UK.
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Hodgson ZG, Meddle SL, Roberts ML, Buchanan KL, Evans MR, Metzdorf R, Gahr M, Healy SD. Spatial ability is impaired and hippocampal mineralocorticoid receptor mRNA expression reduced in zebra finches (Taeniopygia guttata) selected for acute high corticosterone response to stress. Proc Biol Sci 2007; 274:239-45. [PMID: 17148253 PMCID: PMC1685847 DOI: 10.1098/rspb.2006.3704] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In mammals, stress hormones have profound influences on spatial learning and memory. Here, we investigated whether glucocorticoids influence cognitive abilities in birds by testing a line of zebra finches selectively bred to respond to an acute stressor with high plasma corticosterone (CORT) levels. Cognitive performance was assessed by spatial and visual one-trial associative memory tasks. Task performance in the high CORT birds was compared with that of the random-bred birds from a control breeding line. The birds selected for high CORT in response to an acute stressor performed less well than the controls in the spatial task, but there were no significant differences between the lines in performance during the visual task. The birds from the two lines did not differ in their plasma CORT levels immediately after the performance of the memory tasks; nevertheless, there were significant differences in peak plasma CORT between the lines. The high CORT birds also had significantly lower mineralocorticoid receptor mRNA expression in the hippocampus than the control birds. There was no measurable difference between the lines in glucocorticoid receptor mRNA density in either the hippocampus or the paraventricular nucleus. Together, these findings provide evidence to suggest that stress hormones have important regulatory roles in avian spatial cognition.
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Affiliation(s)
- Zoë G Hodgson
- Institute of Evolutionary Biology, School of Biological Sciences, University of EdinburghEdinburgh EH9 3JR, UK
| | - Simone L Meddle
- Centre for Integrative Biology, College of Medicine and Veterinary Medicine, University of EdinburghHugh Robson Building, George Square EH8 9XD, UK
- Author for correspondence ()
| | - Mark L Roberts
- Department of Biological Sciences, University of StirlingStirling FK9 4LA, UK
- Vogelwarte Radolfzell, Max Planck Institute for OrnithologySchloss Moeggingen, Schlossallee 2, 78315 Radolfzell, Germany
| | | | - Matthew R Evans
- Centre for Ecology and Conservation, University of ExeterCornwall Campus, Penryn, Cornwall TR10 9EZ, UK
| | - Reinhold Metzdorf
- Department of Behavioural Neurobiology, Max Planck Institute for OrnithologyPostfach 1564, 82319 Seewiesen, Germany
| | - Manfred Gahr
- Department of Behavioural Neurobiology, Max Planck Institute for OrnithologyPostfach 1564, 82319 Seewiesen, Germany
| | - Susan D Healy
- Institute of Evolutionary Biology, School of Biological Sciences, University of EdinburghEdinburgh EH9 3JR, UK
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Korz V, Frey JU. Hormonal and monoamine signaling during reinforcement of hippocampal long-term potentiation and memory retrieval. Learn Mem 2007; 14:160-6. [PMID: 17351139 PMCID: PMC1838557 DOI: 10.1101/lm.459807] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 01/09/2007] [Indexed: 11/24/2022]
Abstract
Recently it was shown that holeboard training can reinforce, i.e., transform early-LTP into late-LTP in the dentate gyrus during the initial formation of a long-term spatial reference memory in rats. The consolidation of LTP as well as of the reference memory was dependent on protein synthesis. We have now investigated the transmitter systems involved in this reinforcement and found that LTP-consolidation and memory retrieval were dependent on beta-adrenergic, dopaminergic, and mineralocorticoid receptor (MR) activation, whereas glucocorticoid receptors (GRs) were not involved. Blockade of the beta-adrenergic signaling pathway significantly increased the number of reference memory errors compared with MR and dopamine receptor inhibition. In addition, beta-adrenergic blockade impaired the working memory. Therefore, we suggest that beta-adrenergic receptor activation is the main signaling system required for the retrieval of spatial memory. In addition, other modulatory interactions such as dopaminergic as well as MR systems are involved. This result points to specific roles of different modulatory systems during the retrieval of specific components of spatial memory. The data provide evidence for similar integrative interactions between different signaling systems during cellular memory processes.
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Affiliation(s)
- Volker Korz
- Department of Neurophysiology, Leibniz Institute for Neurobiology, Magdeburg, Germany.
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Nagaraja N, Andrade C, Sudha S, Madan Singh N, Chandra JS, Venkataraman BV. Glucocorticoid mechanisms may contribute to ECT-induced retrograde amnesia. Psychopharmacology (Berl) 2007; 190:73-80. [PMID: 17072590 DOI: 10.1007/s00213-006-0593-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2006] [Accepted: 08/31/2006] [Indexed: 11/30/2022]
Abstract
RATIONALE Cortisol levels rise sharply immediately after electroconvulsive therapy (ECT); the resultant stimulation of steroid receptors in the hippocampus may be beneficial or harmful to cognition, depending on the magnitude of the stimulation. Steroid mechanisms may therefore modulate ECT-induced amnesia. OBJECTIVES Using mifepristone (a glucocorticoid receptor antagonist) as a chemical probe, we sought to examine steroid mechanisms in an animal model of ECT-induced retrograde amnesia. MATERIALS AND METHODS Adult, male Wistar rats (n = 68) trained in a step-through passive-avoidance task were randomized to receive mifepristone (20 or 40 mg kg(-1) day(-1)) or vehicle (control). These treatments were administered 1 day before the electroconvulsive shock (ECS) course and, again, 1 h before each of five once-daily true (30 mC) or sham ECS. Recall of pre-ECS learning was tested 1 day after the last ECS. RESULTS Relative to sham ECS, true ECS resulted in significant retrograde amnesia in the vehicle group but not in either of the mifepristone groups. In sham ECS-treated animals, mifepristone did not significantly influence recall. In ECS-treated rats, the higher but not the lower dose of mifepristone was associated with significant protection against the retrograde amnesia evident in the vehicle group. CONCLUSION Mifepristone administered before the ECT seizure may attenuate ECT-induced retrograde amnesia. This suggests that glucocorticoid mechanisms may contribute to ECT-induced retrograde amnesia.
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Otte C, Moritz S, Yassouridis A, Koop M, Madrischewski AM, Wiedemann K, Kellner M. Blockade of the mineralocorticoid receptor in healthy men: effects on experimentally induced panic symptoms, stress hormones, and cognition. Neuropsychopharmacology 2007; 32:232-8. [PMID: 17035932 DOI: 10.1038/sj.npp.1301217] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Animal studies have shown that blockade of central mineralocorticoid receptors (MR) has anxiolytic effects and impairs several aspects of cognitive function. No study to date assessed the effects of MR blockade on anxiety and cognitive function in humans. In the present study, 16 healthy young men were treated either with placebo or with 300 mg spironolactone, a MR-antagonist, at 1100, 1330, and 1630 hours in a balanced cross-over design with the two study conditions being 1 week apart. At 1500 hours, the panic symptoms provoking compound cholecystokinin-tetrapeptide (CCK-4) was administered i.v. on both occasions and panic symptoms were assessed. We measured plasma ACTH and cortisol between 1300 and 1900 hours and assessed cognitive function between 1800 and 1900 hours. CCK-4 elicited panic symptoms and increased ACTH and cortisol secretion in both conditions. Intensity of panic symptoms after CCK-4 was not different between spironolactone and placebo. Spironolactone significantly impaired selective attention and delayed recall of visuospatial memory, and diminished set shifting/mental flexibility on a trend level. Pretreatment with spironolactone led to higher baseline cortisol levels compared to placebo whereas no differences in stimulated cortisol, baseline ACTH, and stimulated ACTH emerged. Blockade of MR with spironolactone increases baseline cortisol secretion and impairs cognitive function but has no effect on experimentally induced panic symptoms in humans, for the study design and dosage of spironolactone used. The domains of cognitive function that are impaired after blockade of MR in men, that is, selective attention, visuospatial memory, and mental flexibility/set shifting appear to be remarkably similar to those described in animal studies.
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Affiliation(s)
- Christian Otte
- Department of Psychiatry and Psychotherapy, University Hospital Hamburg-Eppendorf, Hamburg, Germany.
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Affiliation(s)
- Mohammad R Zarrindast
- Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Berger S, Wolfer DP, Selbach O, Alter H, Erdmann G, Reichardt HM, Chepkova AN, Welzl H, Haas HL, Lipp HP, Schütz G. Loss of the limbic mineralocorticoid receptor impairs behavioral plasticity. Proc Natl Acad Sci U S A 2005; 103:195-200. [PMID: 16368758 PMCID: PMC1324975 DOI: 10.1073/pnas.0503878102] [Citation(s) in RCA: 211] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Corticosteroid action in the brain is mediated by the mineralocorticoid (MR) and the glucocorticoid (GR) receptor. Disturbances in MR- and GR-mediated effects are thought to impair cognition, behavior, and endocrine control. To assess the function of the limbic MR in these processes, we inactivated the MR gene in the forebrain of the mouse using the Cre/loxP-recombination system. We screened the mice with a limbic MR deficiency in various learning and exploration tests. The mutant mice show impaired learning of the water-maze task and deficits in measures of working memory on the radial maze due to behavioral perseverance and stereotypy. They exhibit a hyperreactivity toward a novel object but normal anxiety-like behavior. The behavioral changes are associated with abnormalities of the mossy fiber projection and an up-regulation of GR expression in the hippocampus. Adult mutant mice show normal corticosterone levels at circadian trough and peak. This genetic model provides important information about the consequences of a permanently altered balance between limbic MR and GR, with implications for stress-related neuroendocrine and neuropsychiatric diseases.
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Affiliation(s)
- Stefan Berger
- German Cancer Research Center, Division Molecular Biology of the Cell I, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Amin MS, Wang HW, Reza E, Whitman SC, Tuana BS, Leenen FHH. Distribution of epithelial sodium channels and mineralocorticoid receptors in cardiovascular regulatory centers in rat brain. Am J Physiol Regul Integr Comp Physiol 2005; 289:R1787-97. [PMID: 16141309 DOI: 10.1152/ajpregu.00063.2005] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epithelial sodium channels (ENaC) are important for regulating sodium transport across epithelia. Functional studies indicate that neural mechanisms acting through mineralocorticoid receptors (MR) and sodium channels (presumably ENaC) are crucial to the development of sympathoexcitation and hypertension in experimental models of salt-sensitive hypertension. However, expression and localization of the ENaC in cardiovascular regulatory centers of the brain have not yet been studied. RT-PCR and immunohistochemistry were performed to study ENaC and MR expression at the mRNA and protein levels, respectively. Both mRNA and protein for alpha-, beta-, and gamma-ENaC subunits and MR were found to be expressed in the rat brain. All three ENaC subunits and MR were present in the supraoptic nucleus, magnocellular paraventricular nucleus, hippocampus, choroid plexus, ependyma, and brain blood vessels, suggesting the presence of multimeric channels and possible regulation by mineralocorticoids. In most cortical areas, thalamus, amygdala, and suprachiasmatic nucleus, notable expression of gamma-ENaC was undetectable, whereas alpha- and beta-ENaC were abundantly expressed pointing to the possibility of a heterogeneous population of channels. The findings suggest that stoichiometrically different populations of ENaC may be present in both epithelial and neural components in the brain, which may contribute to regulation of cerebrospinal fluid and interstitial Na+ concentration as well as neuronal excitation.
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Affiliation(s)
- Md Shahrier Amin
- Hypertension Unit, Univ. of Ottawa Heart Institute, Ottawa, ON, Canada K1Y 4W7
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Lai M, Seckl J, Macleod M. Overexpression of the mineralocorticoid receptor protects against injury in PC12 cells. ACTA ACUST UNITED AC 2005; 135:276-9. [PMID: 15857689 DOI: 10.1016/j.molbrainres.2004.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2004] [Revised: 11/03/2004] [Accepted: 11/06/2004] [Indexed: 11/19/2022]
Abstract
Mineralocorticoid receptor expression is increased following neuronal injury, and this is associated with increased neuronal survival. Here we demonstrate a causal link between overexpression of MR in PC12 cells and protection against death induced by staurosporine and oxygen-glucose deprivation. This survival effect is abrogated by MR antagonism. Drugs which upregulate MR may form the basis for a novel therapeutic approach in conditions such as stroke and head injury.
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Affiliation(s)
- Maggie Lai
- Endocrinology Unit, Molecular Medicine Centre, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, Scotland, UK.
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Conrad CD. THE RELATIONSHIP BETWEEN ACUTE GLUCOCORTICOID LEVELS AND HIPPOCAMPAL FUNCTION DEPENDS UPON TASK AVERSIVENESS AND MEMORY PROCESSING STAGE. NONLINEARITY IN BIOLOGY, TOXICOLOGY, MEDICINE 2005. [PMID: 16601824 PMCID: PMC1431575 DOI: 10.2201/nonlin.003.01.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
This review evaluates the effects of glucocorticoids (GCs), the adrenal steroids released in response to stress, on memory functions requiring the hippocampus in animals and humans. The data support the hypothesis that the learning function between GCs and hippocampal-dependent memory is modulated by 1) the aversive nature of the learning paradigm and 2) stage of memory processing (acquisition, consolidation, retrieval). When tasks are minimally aversive, the glucocorticoid receptor (GR) mediates an inverted U-shaped relationship between GC levels and hippocampal function, while the mineralocorticoid receptor (MR) mediates attentional processes and/or reaction to novelty. This inverted U-shaped relationship during minimally aversive training paradigms describes GC-mediated memory processing at both acquisition and consolidation. In contrast, highly aversive paradigms activate the amygdala and elevate GCs as part of the training procedure, revealing a nonlinear inverted U-shaped relationship during acquisition and a positive linear function during consolidation. Thus, highly aversive tasks that activate the amygdala shift the memory function from an inverted U-shaped curve to a linear representation between GC levels and memory consolidation.
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