1
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Glucocorticoid-Responsive Tissue Plasminogen Activator (tPA) and Its Inhibitor Plasminogen Activator Inhibitor-1 (PAI-1): Relevance in Stress-Related Psychiatric Disorders. Int J Mol Sci 2023; 24:ijms24054496. [PMID: 36901924 PMCID: PMC10003592 DOI: 10.3390/ijms24054496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/02/2023] Open
Abstract
Stressful events trigger a set of complex biological responses which follow a bell-shaped pattern. Low-stress conditions have been shown to elicit beneficial effects, notably on synaptic plasticity together with an increase in cognitive processes. In contrast, overly intense stress can have deleterious behavioral effects leading to several stress-related pathologies such as anxiety, depression, substance use, obsessive-compulsive and stressor- and trauma-related disorders (e.g., post-traumatic stress disorder or PTSD in the case of traumatic events). Over a number of years, we have demonstrated that in response to stress, glucocorticoid hormones (GCs) in the hippocampus mediate a molecular shift in the balance between the expression of the tissue plasminogen activator (tPA) and its own inhibitor plasminogen activator inhibitor-1 (PAI-1) proteins. Interestingly, a shift in favor of PAI-1 was responsible for PTSD-like memory induction. In this review, after describing the biological system involving GCs, we highlight the key role of tPA/PAI-1 imbalance observed in preclinical and clinical studies associated with the emergence of stress-related pathological conditions. Thus, tPA/PAI-1 protein levels could be predictive biomarkers of the subsequent onset of stress-related disorders, and pharmacological modulation of their activity could be a potential new therapeutic approach for these debilitating conditions.
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2
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Arellano Perez AD, Alves J, de Oliveira Alvares L. Re-exposures in the Dark Cycle Promote Attenuation of Fear Memory: Role of the Circadian Cycle and Glucocorticoids. Neuroscience 2022; 505:1-9. [DOI: 10.1016/j.neuroscience.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 09/27/2022] [Accepted: 10/04/2022] [Indexed: 11/17/2022]
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3
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Caputo R, Poirel VJ, Challet E, Meijer JH, Raison S. Bimodal serotonin synthesis in the diurnal rodent, Arvicanthis ansorgei. FASEB J 2022; 36:e22255. [PMID: 35294080 DOI: 10.1096/fj.202101726r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 02/05/2022] [Accepted: 03/04/2022] [Indexed: 11/11/2022]
Abstract
In mammals, behavioral activity is regulated both by the circadian system, orchestrated by the suprachiasmatic nucleus (SCN), and by arousal structures, including the serotonergic system. While the SCN is active at the same astronomical time in diurnal and nocturnal species, little data are available concerning the serotonergic (5HT) system in diurnal mammals. In this study, we investigated the functioning of the 5HT system, which is involved both in regulating the sleep/wake cycle and in synchronizing the SCN, in a diurnal rodent, Arvicanthis ansorgei. Using in situ hybridization, we characterized the anatomical extension of the raphe nuclei and we investigated 24 h mRNA levels of the serotonin rate-limiting enzyme, tryptophan hydroxylase 2 (tph2). Under both 12 h:12 h light/dark (LD) and constant darkness (DD) conditions, tph2 mRNA expression varies significantly over 24 h, displaying a bimodal profile with higher values around the (projected) light transitions. Furthermore, we considered several SCN outputs, namely melatonin, corticosterone, and locomotor activity. In both LD and DD, melatonin profiles display peak levels during the biological night. Corticosterone plasma levels show a bimodal rhythmic profile in both conditions, with higher levels preceding the two peaks of Arvicanthis locomotor activity, occurring at dawn and dusk. These data demonstrate that serotonin synthesis in Arvicanthis is rhythmic and reflects its bimodal behavioral phenotype, but differs from what has been previously described in nocturnal species.
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Affiliation(s)
- Rosanna Caputo
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France.,Department of Molecular Cell Biology, Division of Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Vincent-Joseph Poirel
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Etienne Challet
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
| | - Johanna H Meijer
- Department of Molecular Cell Biology, Division of Neurophysiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Sylvie Raison
- Institute of Cellular and Integrative Neurosciences, CNRS and University of Strasbourg, Strasbourg, France
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4
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Robbers Y, Tersteeg MMH, Meijer JH, Coomans CP. Group housing and social dominance hierarchy affect circadian activity patterns in mice. ROYAL SOCIETY OPEN SCIENCE 2021; 8:201985. [PMID: 33972875 PMCID: PMC8074631 DOI: 10.1098/rsos.201985] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/06/2021] [Indexed: 05/14/2023]
Abstract
In this study, we investigated the effect of social environment on circadian patterns in activity by group housing either six male or six female mice together in a cage, under regular light-dark cycles. Based on the interactions among the animals, the social dominance rank of individual mice was quantitatively established by calculating Elo ratings. Our results indicated that, during our experiment, the social dominance hierarchy was rapidly established, stable yet complex, often showing more than one dominant mouse and several subordinate mice. Moreover, we found that especially dominant male mice, but not female mice, displayed a significantly higher fraction of their activity during daytime. This resulted in reduced rhythm amplitude in dominant males. After division into separate cages, male mice showed an enhancement of their 24 h rhythm, due to lower daytime activity. Recordings of several physiological parameters showed no evidence for reduced health as a potential consequence of reduced rhythm amplitude. For female mice, transfer to individual housing did not affect their daily activity pattern. We conclude that 24 h rhythms under light-dark cycles are influenced by the social environment in males but not in females, and lead to a decrement in behavioural rhythm amplitude that is larger in dominant mice.
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Affiliation(s)
- Yuri Robbers
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Mayke M. H. Tersteeg
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Johanna H. Meijer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
| | - Claudia P. Coomans
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, Leiden, The Netherlands
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5
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A novel mouse model for vulnerability to alcohol dependence induced by early-life adversity. Neurobiol Stress 2020; 13:100269. [PMID: 33344722 PMCID: PMC7739069 DOI: 10.1016/j.ynstr.2020.100269] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 10/16/2020] [Accepted: 11/14/2020] [Indexed: 12/13/2022] Open
Abstract
Childhood adversity increases vulnerability to alcohol use disorders and preclinical models are needed to investigate the underlying neurobiological mechanisms. The present study modeled early-life adversity by rearing male and female C57BL/6J mouse pups in a limited bedding and nesting (LBN) environment, which induces erratic maternal care. As adults, mice were given limited access to two-bottle choice (2BC) alcohol drinking, combined or not with chronic intermittent ethanol (CIE) vapor inhalation to induce alcohol dependence. We tested the hypothesis that LBN rearing might exacerbate or facilitate the emergence of the motivational and affective effects of CIE. Consistent with our hypothesis, although LBN-reared males consumed the same baseline levels of alcohol as controls, they escalated their ethanol intake at an earlier stage of CIE exposure, i.e., after 4 rounds vs. 5 rounds for controls. In contrast, females were insensitive to both LBN rearing and CIE exposure. Males were further subjected to a behavioral test battery. Withdrawal from CIE-2BC increased digging activity and lowered mechanical nociceptive thresholds regardless of early-life conditions. On the other hand, LBN-reared CIE-2BC males showed reduced open arm exploration in the elevated plus maze and increased immobility in the tail suspension test compared to alcohol-naïve counterparts, while no group differences were detected among control-reared males. Finally, LBN rearing and alcohol exposure did not affect grooming in response to a sucrose spray (splash test), novel object recognition, or corticosterone levels. In summary, the LBN experience accelerates the transition from moderate to excessive alcohol drinking and produces additional indices of affective dysfunction during alcohol withdrawal in C57BL/6J male mice. Early-life adversity was generated by rearing C57BL/6J mouse pups in a limited bedding and nesting (LBN) environment. Alcohol dependence was induced in adulthood via chronic intermittent ethanol (CIE) inhalation. The LBN experience accelerated alcohol intake escalation in males. LBN exacerbated affective disturbances upon CIE withdrawal in males. Alcohol intake in females was insensitive to both LBN and CIE.
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6
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Schouten M, Bielefeld P, Garcia-Corzo L, Passchier EMJ, Gradari S, Jungenitz T, Pons-Espinal M, Gebara E, Martín-Suárez S, Lucassen PJ, De Vries HE, Trejo JL, Schwarzacher SW, De Pietri Tonelli D, Toni N, Mira H, Encinas JM, Fitzsimons CP. Circadian glucocorticoid oscillations preserve a population of adult hippocampal neural stem cells in the aging brain. Mol Psychiatry 2020; 25:1382-1405. [PMID: 31222184 PMCID: PMC7303016 DOI: 10.1038/s41380-019-0440-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 04/09/2019] [Accepted: 04/29/2019] [Indexed: 12/17/2022]
Abstract
A decrease in adult hippocampal neurogenesis has been linked to age-related cognitive impairment. However, the mechanisms involved in this age-related reduction remain elusive. Glucocorticoid hormones (GC) are important regulators of neural stem/precursor cells (NSPC) proliferation. GC are released from the adrenal glands in ultradian secretory pulses that generate characteristic circadian oscillations. Here, we investigated the hypothesis that GC oscillations prevent NSPC activation and preserve a quiescent NSPC pool in the aging hippocampus. We found that hippocampal NSPC populations lacking expression of the glucocorticoid receptor (GR) decayed exponentially with age, while GR-positive populations decayed linearly and predominated in the hippocampus from middle age onwards. Importantly, GC oscillations controlled NSPC activation and GR knockdown reactivated NSPC proliferation in aged mice. When modeled in primary hippocampal NSPC cultures, GC oscillations control cell cycle progression and induce specific genome-wide DNA methylation profiles. GC oscillations induced lasting changes in the methylation state of a group of gene promoters associated with cell cycle regulation and the canonical Wnt signaling pathway. Finally, in a mouse model of accelerated aging, we show that disruption of GC oscillations induces lasting changes in dendritic complexity, spine numbers and morphology of newborn granule neurons. Together, these results indicate that GC oscillations preserve a population of GR-expressing NSPC during aging, preventing their activation possibly by epigenetic programming through methylation of specific gene promoters. Our observations suggest a novel mechanism mediated by GC that controls NSPC proliferation and preserves a dormant NSPC pool, possibly contributing to a neuroplasticity reserve in the aging brain.
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Affiliation(s)
- M Schouten
- Neuroscience Collaboration, Swammerdam Institute for Life Sciences, Faculty of Sciences, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - P Bielefeld
- Neuroscience Collaboration, Swammerdam Institute for Life Sciences, Faculty of Sciences, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - L Garcia-Corzo
- Biomedicine Institute of Valencia (IBV), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - E M J Passchier
- Neuroscience Collaboration, Swammerdam Institute for Life Sciences, Faculty of Sciences, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - S Gradari
- Cajal Institute, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - T Jungenitz
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - M Pons-Espinal
- Neurobiology of miRNA Lab, Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, Genoa, Italy
| | - E Gebara
- Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | | | - P J Lucassen
- Neuroscience Collaboration, Swammerdam Institute for Life Sciences, Faculty of Sciences, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - H E De Vries
- Department of Molecular Cell Biology and Immunology, VU University Medical Center, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - J L Trejo
- Cajal Institute, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - S W Schwarzacher
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - D De Pietri Tonelli
- Neurobiology of miRNA Lab, Neuroscience and Brain Technologies Department, Istituto Italiano di Tecnologia, Genoa, Italy
| | - N Toni
- Center for Psychiatric Neuroscience, Department of Psychiatry, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - H Mira
- Biomedicine Institute of Valencia (IBV), Consejo Superior de Investigaciones Científicas (CSIC), Valencia, Spain
| | - J M Encinas
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Ikerbasque, The Basque Foundation for Science, Bilbao, Spain
- University of the Basque Country (UPV/EHU), Leioa, Spain
| | - C P Fitzsimons
- Neuroscience Collaboration, Swammerdam Institute for Life Sciences, Faculty of Sciences, Amsterdam Neuroscience, University of Amsterdam, Amsterdam, The Netherlands.
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7
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Kumstel S, Wendt EHU, Eichberg J, Talbot SR, Häger C, Zhang X, Abdelrahman A, Schönrogge M, Palme R, Bleich A, Vollmar B, Zechner D. Grading animal distress and side effects of therapies. Ann N Y Acad Sci 2020; 1473:20-34. [PMID: 32207155 DOI: 10.1111/nyas.14338] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/30/2020] [Accepted: 03/05/2020] [Indexed: 12/14/2022]
Abstract
In order to combine high-quality research with minimal harm to animals, a prospective severity assessment for animal experiments is legally required in many countries. In addition, an assessment of the evidence-based severity level might allow realistic harm-benefit analysis and the appraisal of refinement methods. However, only a few examples describe the distress of animals by simple, cost-efficient, and noninvasive methods. We, therefore, evaluated the severity of an orthotopic mouse model for pancreatic cancer using C57BL/6J mice when pursuing two different chemotherapies. We assessed fecal corticosterone metabolites, body weight, distress score, and burrowing, as well as nesting activity. Moreover, we established a multifactorial model using multivariate logistic regression to describe animal distress. This multifactorial analysis revealed that metformin + galloflavin treatment caused higher distress than metformin + α-cyano-4-hydroxycinnamate therapy. Similar results were obtained by using the best cutoff calculated by Youden's J index when using only single parameters, such as burrowing activity or fecal corticosterone metabolite concentration. Thus, the present study revealed that single readout parameters, as well as multivariate analysis, can help to assess the severity of animal experiments and detect side effects of therapies.
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Affiliation(s)
- Simone Kumstel
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Edgar H U Wendt
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Johanna Eichberg
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Steven R Talbot
- Institute for Laboratory Animal Science, Hannover Medical School, Hanover, Germany
| | - Christine Häger
- Institute for Laboratory Animal Science, Hannover Medical School, Hanover, Germany
| | - Xianbin Zhang
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Ahmed Abdelrahman
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Maria Schönrogge
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, Department of Biomedical Sciences, University of Veterinary Medicine, Vienna, Austria
| | - André Bleich
- Institute for Laboratory Animal Science, Hannover Medical School, Hanover, Germany
| | - Brigitte Vollmar
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
| | - Dietmar Zechner
- Rudolf-Zenker Institute of Experimental Surgery, University Medical Center, Rostock, Germany
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8
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Focke CMB, Iremonger KJ. Rhythmicity matters: Circadian and ultradian patterns of HPA axis activity. Mol Cell Endocrinol 2020; 501:110652. [PMID: 31738971 DOI: 10.1016/j.mce.2019.110652] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 10/29/2019] [Accepted: 11/11/2019] [Indexed: 12/15/2022]
Abstract
Oscillations are a fundamental feature of neural and endocrine systems. The hypothalamic-pituitary-adrenal (HPA) axis dynamically controls corticosteroid secretion in basal conditions and in response to stress. Across the 24-h day, HPA axis activity oscillates with both an ultradian and circadian rhythm. These rhythms have been shown to be important for regulating metabolism, inflammation, mood, cognition and stress responsiveness. Here we will discuss the neural and endocrine mechanisms driving these rhythms, the physiological importance of these rhythms and health consequences when they are disrupted.
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Affiliation(s)
- Caroline M B Focke
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Karl J Iremonger
- Centre for Neuroendocrinology, Department of Physiology, University of Otago, Dunedin, New Zealand.
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9
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A novel multi-parametric analysis of non-invasive methods to assess animal distress during chronic pancreatitis. Sci Rep 2019; 9:14084. [PMID: 31575986 PMCID: PMC6773730 DOI: 10.1038/s41598-019-50682-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/17/2019] [Indexed: 02/06/2023] Open
Abstract
Ethical responsibility, legal requirements and the need to improve the quality of research create a growing interest in the welfare of laboratory animals. Judging the welfare of animals requires readout parameters, which are valid and sensitive as well as specific to assess distress after different interventions. In the present study, we evaluated the sensitivity and specificity of different non-invasive parameters (body weight change, faecal corticosterone metabolites concentration, burrowing and nesting activity) by receiver operating characteristic curves and judged the merit of a multi-parametric analysis by logistic regression. Chronic pancreatitis as well as laparotomy caused significant changes in all parameters. However, the accuracy of these parameters was different between the two animal models. In both animal models, the multi-parametric analysis relying on all the readout parameters had the highest accuracy when predicting distress. This multi-parametric analysis revealed that C57BL/6 mice during the course of chronic pancreatitis often experienced less distress than mice after laparotomy. Interestingly these data also suggest that distress does not steadily increase during chronic pancreatitis. In conclusion, combining these non-invasive methods for severity assessment represents a reliable approach to evaluate animal distress in models such as chronic pancreatitis.
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10
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Grading Distress of Different Animal Models for Gastrointestinal Diseases Based on Plasma Corticosterone Kinetics. Animals (Basel) 2019; 9:ani9040145. [PMID: 30987232 PMCID: PMC6523747 DOI: 10.3390/ani9040145] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 03/25/2019] [Accepted: 03/31/2019] [Indexed: 02/06/2023] Open
Abstract
Simple Summary Animal welfare is an important aspect of biomedical research. Many regulations have been implemented to combine high quality of research with minimal harm to laboratory animals. These guidelines also demand a prospective severity assessment of each animal model. A comparison of distress between animal models could allow realistic harm and benefit analysis and an appropriate use of refinement methods. However, studies comparing distress between different animal models are still rare. One good parameter for analyzing distress is the concentration of the stress hormone corticosterone in the blood. Therefore, we compared the corticosterone kinetics of distinct gastrointestinal animal models. The aim of this study was to evaluate which parameter the highest corticosterone concentration or the duration of increased stress hormone level could be used to quantify distress. We observed a significant increase of corticosterone 30 min after stress induction in all animal models. However, the corticosterone kinetics differed between the distinct interventions. Both the absolute value and the duration of increased corticosterone level correlated directly with an assessed distress score. We conclude that both variables of corticosterone kinetics are valid parameters to compare distress between animal models. Abstract Comparative studies for evaluating distress in established animal models are still rare. However, this issue is becoming more important as a consequence of worldwide appreciation of animal welfare. One good parameter for evaluating distress is the quantification of corticosterone. We hypothesized that not just the absolute value but also the duration of increased corticosterone concentration in the blood is an important aspect for evaluating animal distress. Therefore, we analyzed plasma corticosterone concentrations 30, 60, 120, and 240 min after induction of pancreatitis by cerulein, liver damage by carbon tetrachloride, liver damage by bile duct ligation, and after orthotopic injection of pancreatic cancer cells. We also evaluated corticosterone kinetics after injection of distinct carrier substances. Compared to phosphate buffered saline, dimethyl sulfoxide leads to dose-dependent higher and longer-lasting circulating corticosterone concentrations. In all disease models, we observed significantly increased corticosterone concentration 30 min after stress induction. However, the corticosterone kinetics differed among the animal models. Both the absolute value of corticosterone concentration and the duration correlated positively with the quantification of animal distress by a score sheet. This suggests that both variables of corticosterone kinetics might provide a solid basis for comparing and grading distress of different animal models.
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11
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Duncan MJ. Interacting influences of aging and Alzheimer's disease on circadian rhythms. Eur J Neurosci 2019; 51:310-325. [DOI: 10.1111/ejn.14358] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/03/2019] [Accepted: 01/11/2019] [Indexed: 01/01/2023]
Affiliation(s)
- Marilyn J. Duncan
- Department of NeuroscienceUniversity of Kentucky Medical School Lexington Kentucky
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12
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Lagraauw HM, Wezel A, van der Velden D, Kuiper J, Bot I. Stress-induced mast cell activation contributes to atherosclerotic plaque destabilization. Sci Rep 2019; 9:2134. [PMID: 30765859 PMCID: PMC6375972 DOI: 10.1038/s41598-019-38679-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 12/31/2018] [Indexed: 01/15/2023] Open
Abstract
Mast cells accumulate in the perivascular tissue during atherosclerotic plaque progression and contribute to plaque destabilization. However, the specific triggers for mast cell activation in atherosclerosis remain unresolved. We hypothesized that psychological stress-induced activation of mast cells may contribute to plaque destabilization. To investigate this, apoE−/− mice on Western-type diet were exposed to 120′ restraint stress. A single episode of restraint caused a significant increase in mast cell activation in the heart. In addition to a rise in serum corticosterone and changes in circulating leukocyte populations, we observed an increase in the circulating pro-inflammatory cytokine interleukin (IL)-6 in the stressed mice. Subsequent characterization of the atherosclerotic plaques revealed a high incidence and larger size of intraplaque hemorrhages in stressed mice. In mast cell-deficient apoE−/− mice, restraint stress affected circulating leukocyte levels, but did not increase plasma IL-6 levels. Furthermore, we did not observe any intraplaque hemorrhages in these mice upon stress, strongly indicating the involvement of a mast cell-dependent response to stress in atherosclerotic plaque destabilization. In conclusion, we demonstrate that acute stress activates mast cells, which induces the incidence of intraplaque hemorrhage in vivo, identifying acute stress as a risk factor for atherosclerotic plaque destabilization.
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Affiliation(s)
- H Maxime Lagraauw
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.,Boehringer Ingelheim Pharma GmbH & Co, Biberach an der Riß, Germany
| | - Anouk Wezel
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.,Department of Surgery, Leiden University Medical Center, Leiden, The Netherlands.,Haaglanden Medical Centre, Westeinde Hospital, The Hague, The Netherlands
| | - Daniël van der Velden
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.,Department of Rheumatology, Leiden University Medical Center, Leiden, The Netherlands.,Hogeschool Utrecht, Utrecht, The Netherlands
| | - Johan Kuiper
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands
| | - Ilze Bot
- Division of BioTherapeutics, Leiden Academic Centre for Drug Research, Leiden University, Leiden, The Netherlands.
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13
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Nkomozepi P, Mazengenya P, Ihunwo AO. Age-related changes in Ki-67 and DCX expression in the BALB/ c mouse (Mus Musculus) brain. Int J Dev Neurosci 2018; 72:36-47. [PMID: 30472241 DOI: 10.1016/j.ijdevneu.2018.11.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/02/2018] [Accepted: 11/19/2018] [Indexed: 01/15/2023] Open
Abstract
Several studies have identified age as one of the strongest regulators of neurogenesis in the mammalian brain. However, previous age-related studies focused mainly on changes in neurogenesis during different stages of adulthood and did not describe changes in neurogenesis through the different life history stages of the animal. The aim of this study was therefore to determine time course changes in neurogenesis in the male BALB/c mouse brain at postnatal ages 1 week to 12 weeks, spanning juvenile, sub adult and adult life history stages. To achieve this, Ki-67 and DCX immunohistochemistry was used to assess changes in cell proliferation and neuronal incorporation respectively. Ki-67 expression was mainly observed in the olfactory bulb, rostral migratory stream, sub ventricular zone of lateral ventricle and the sub granular zone of the dentate gyrus. In addition, fewer Ki-67 positive cells were also observed in the neocortex, cerebellum and tectum. DCX was expressed in similar regions as Ki-67 except for the cerebellum and tectum. Expression of both Ki-67 and DCX sharply decreased with advancing age or life history stages in the sub ventricular zone, rostral migratory stream and sub granular zone of the BALB/c mouse brain. Neurogenesis therefore persists throughout all life history stages in the BALB/c mouse brain although it decreases with age.
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Affiliation(s)
- Pilani Nkomozepi
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2190, South Africa; Department of Human Anatomy and Physiology, Faculty of Health Sciences, University of Johannesburg, Cnr Siemert and Beit Streets, Doornfontein, 2094, Johannesburg, South Africa
| | - Pedzisai Mazengenya
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2190, South Africa
| | - Amadi O Ihunwo
- School of Anatomical Sciences, Faculty of Health Sciences, University of the Witwatersrand, 7 York Road, Parktown, Johannesburg, 2190, South Africa.
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14
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Dalm S, Karssen AM, Meijer OC, Belanoff JK, de Kloet ER. Resetting the Stress System with a Mifepristone Challenge. Cell Mol Neurobiol 2018; 39:503-522. [PMID: 30173378 PMCID: PMC6469632 DOI: 10.1007/s10571-018-0614-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 08/18/2018] [Indexed: 12/20/2022]
Abstract
Psychotic depression is characterized by elevated circulating cortisol, and high daily doses of the glucocorticoid/progesterone antagonist mifepristone for 1 week are required for significant improvement. Using a rodent model, we find that such high doses of mifepristone are needed because the antagonist is rapidly degraded and poorly penetrates the blood–brain barrier, but seems to facilitate the entry of cortisol. We also report that in male C57BL/6J mice, after a 7-day treatment with a high dose of mifepristone, basal blood corticosterone levels were similar to that of vehicle controls. This is surprising because after the first mifepristone challenge, corticosterone remained elevated for about 16 h, and then decreased towards vehicle control levels at 24 h. At that time, stress-induced corticosterone levels of the 1xMIF were sevenfold higher than the 7xMIF group, the latter response being twofold lower than controls. The 1xMIF mice showed behavioral hyperactivity during exploration of the circular hole board, while the 7xMIF mice rather engaged in serial search patterns. To explain this rapid reset of corticosterone secretion upon recurrent mifepristone administration, we suggest the following: (i) A rebound glucocorticoid feedback after cessation of mifepristone treatment. (ii) Glucocorticoid agonism in transrepression and recruitment of cell-specific coregulator cocktails. (iii) A more prominent role of brain MR function in control of stress circuit activity. An overview table of neuroendocrine MIF effects is provided. The data are of interest for understanding the mechanistic underpinning of stress system reset as treatment strategy for stress-related diseases.
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Affiliation(s)
- Sergiu Dalm
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research and Leiden University Medical Center, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
| | - Adriaan M Karssen
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research and Leiden University Medical Center, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands
| | - Onno C Meijer
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research and Leiden University Medical Center, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands.,Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C-7-44, Postal zone C7-Q, PO Box 9600, Leiden, The Netherlands
| | | | - E Ronald de Kloet
- Division of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research and Leiden University Medical Center, Leiden University, P.O. Box 9502, 2300 RA, Leiden, The Netherlands. .,Department of Medicine, Division of Endocrinology, Leiden University Medical Center, Room C-7-44, Postal zone C7-Q, PO Box 9600, Leiden, The Netherlands.
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15
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Son GH, Cha HK, Chung S, Kim K. Multimodal Regulation of Circadian Glucocorticoid Rhythm by Central and Adrenal Clocks. J Endocr Soc 2018; 2:444-459. [PMID: 29713692 PMCID: PMC5915959 DOI: 10.1210/js.2018-00021] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 04/03/2018] [Indexed: 02/08/2023] Open
Abstract
Adrenal glucocorticoids (GCs) control a wide range of physiological processes, including metabolism, cardiovascular and pulmonary activities, immune and inflammatory responses, and various brain functions. During stress responses, GCs are secreted through activation of the hypothalamic-pituitary-adrenal axis, whereas circulating GC levels in unstressed states follow a robust circadian oscillation with a peak around the onset of the active period of a day. A recent advance in chronobiological research has revealed that multiple regulatory mechanisms, along with classical neuroendocrine regulation, underlie this GC circadian rhythm. The hierarchically organized circadian system, with a central pacemaker in the suprachiasmatic nucleus of the hypothalamus and local oscillators in peripheral tissues, including the adrenal gland, mediates periodicities in physiological processes in mammals. In this review, we primarily focus on our understanding of the circadian regulation of adrenal GC rhythm, with particular attention to the cooperative actions of the suprachiasmatic nucleus central and adrenal local clocks, and the clinical implications of this rhythm in human diseases.
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Affiliation(s)
- Gi Hoon Son
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Korea
| | - Hyo Kyeong Cha
- Department of Biomedical Sciences, College of Medicine, Korea University, Seoul, Korea
| | - Sooyoung Chung
- Department of Brain and Cognitive Sciences, Scranton College, Ewha Womans University, Seoul, Korea
| | - Kyungjin Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Korea.,Korea Brain Research Institute, Daegu, Korea
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16
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Smithers HE, Terry JR, Brown JT, Randall AD. Aging-Associated Changes to Intrinsic Neuronal Excitability in the Bed Nucleus of the Stria Terminalis Is Cell Type-Dependent. Front Aging Neurosci 2017; 9:424. [PMID: 29311907 PMCID: PMC5744640 DOI: 10.3389/fnagi.2017.00424] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/11/2017] [Indexed: 12/16/2022] Open
Abstract
Intrinsic neuronal excitability has been reported to change during normal aging. The bed nucleus of the stria terminalis (BNST), a limbic forebrain structure, is involved in fear, stress and anxiety; behavioral features that exhibit age-dependent properties. To examine the effect of aging on intrinsic neuronal properties in BNST we compared patch clamp recordings from cohorts of female mice at two ages, 3–4 months (Young) and 29–30 months (Aged) focusing on 2 types of BNST neurons. Aged Type I neurons exhibited a hyperpolarized resting membrane potential (RMP) of circa -80 mV compared to circa -70 mV in the Young. A key finding in this study is a hyper-excitability of Type II neurons with age reflected in an increase in firing frequency in response to depolarizing current injections; activation of Type II neurons is believed to dampen anxiety like responses. Such age-related changes in intrinsic neurophysiological function are likely to modulate how the limbic system, acting via BNST, shapes function in the HPA-axis.
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Affiliation(s)
- Hannah E Smithers
- Hatherly Laboratory, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom
| | - John R Terry
- College of Engineering, Mathematics and Physical Sciences, Living Systems Institute, University of Exeter, Exeter, United Kingdom
| | - Jon T Brown
- Hatherly Laboratory, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom
| | - Andrew D Randall
- Hatherly Laboratory, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, United Kingdom
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17
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Circadian Rhythms in Fear Conditioning: An Overview of Behavioral, Brain System, and Molecular Interactions. Neural Plast 2017; 2017:3750307. [PMID: 28698810 PMCID: PMC5494081 DOI: 10.1155/2017/3750307] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/28/2017] [Accepted: 05/14/2017] [Indexed: 12/17/2022] Open
Abstract
The formation of fear memories is a powerful and highly evolutionary conserved mechanism that serves the behavioral adaptation to environmental threats. Accordingly, classical fear conditioning paradigms have been employed to investigate fundamental molecular processes of memory formation. Evidence suggests that a circadian regulation mechanism allows for a timestamping of such fear memories and controlling memory salience during both their acquisition and their modification after retrieval. These mechanisms include an expression of molecular clocks in neurons of the amygdala, hippocampus, and medial prefrontal cortex and their tight interaction with the intracellular signaling pathways that mediate neural plasticity and information storage. The cellular activities are coordinated across different brain regions and neural circuits through the release of glucocorticoids and neuromodulators such as acetylcholine, which integrate circadian and memory-related activation. Disturbance of this interplay by circadian phase shifts or traumatic experience appears to be an important factor in the development of stress-related psychopathology, considering these circadian components are of critical importance for optimizing therapeutic approaches to these disorders.
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18
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Continuous infusion of manganese improves contrast and reduces side effects in manganese-enhanced magnetic resonance imaging studies. Neuroimage 2016; 147:1-9. [PMID: 27777173 DOI: 10.1016/j.neuroimage.2016.09.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 09/04/2016] [Accepted: 09/13/2016] [Indexed: 01/04/2023] Open
Abstract
The ability to administer systemically high doses of manganese as contrast agent while circumventing its toxicity is of particular interest for exploratory MRI studies of the brain. Administering low doses either repeatedly or continuously over time has been shown to enable the acquisition of satisfactory MRI images of the mouse brain without apparent side effects. Here we have systematically compared the obtained MRI contrast and recorded potential systemic side effects such as stress response and muscle strength impairment in relation to the achieved contrast. We show in mice that administering MnCl2 via osmotic infusion pumps allows for a side-effect free delivery of a high cumulative dose of manganese chloride (480mg/kg bodyweight in 8 days). High contrast in MRI was achieved while we did not observe the weight loss or distress seen in other studies where mice received manganese via fractionated intraperitoneal injections of lower doses of manganese. As the normal daily conduct of the mice was not affected, this new manganese delivery method might be of particular use to study brain activity over several days. This may facilitate the phenotyping of new transgenic mouse models, the study of chronic disease models and the monitoring of changes in brain activity in long-term behavioral studies.
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Kolbe T, Palme R, Tichy A, Rülicke T. Lifetime Dependent Variation of Stress Hormone Metabolites in Feces of Two Laboratory Mouse Strains. PLoS One 2015; 10:e0136112. [PMID: 26284365 PMCID: PMC4540567 DOI: 10.1371/journal.pone.0136112] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 07/29/2015] [Indexed: 12/26/2022] Open
Abstract
Non-invasive measurement of stress hormone metabolites in feces has become routine practice for the evaluation of distress and pain in animal experiments. Since metabolism and excretion of glucocorticoids may be variable, awareness and adequate consideration of influencing factors are essential for accurate monitoring of adrenocortical activity. Reference values are usually provided by baselines compiled prior to the experiment and by age matched controls. The comparison of stress hormone levels between animals of different ages or between studies looking at hormone levels at the beginning and at the end of a long term study might be biased by age-related effects. In this study we analyzed fecal corticosterone metabolites (FCM) during the lifetime of untreated female mice of the strains C57BL/6NCrl and Crl:CD1. For this purpose feces for each individual mouse were collected every two months over a period of 24 hours, at intervals of four hours, until the age of 26 months. Results of the study revealed that age of the animals had a significant impact on the level and circadian rhythm of stress hormone metabolites. Furthermore, long-term observation of mice revealed a strain specific excretion profile of FCM influenced by strong seasonal variability.
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Affiliation(s)
- Thomas Kolbe
- Biomodels Austria, University of Veterinary Medicine Vienna, Vienna, Austria
- IFA-Tulln, University of Natural Resources and Life Sciences, Tulln, Austria
| | - Rupert Palme
- Unit of Physiology, Pathophysiology and Experimental Endocrinology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Alexander Tichy
- Bioinformatics and Biostatistics Platform, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Thomas Rülicke
- Institute of Laboratory Animal Science, University of Veterinary Medicine Vienna, Vienna, Austria
- * E-mail:
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20
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Grosbellet E, Zahn S, Arrivé M, Dumont S, Gourmelen S, Pévet P, Challet E, Criscuolo F. Circadian desynchronization triggers premature cellular aging in a diurnal rodent. FASEB J 2015; 29:4794-803. [PMID: 26260033 DOI: 10.1096/fj.14-266817] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 07/27/2015] [Indexed: 12/16/2022]
Abstract
Chronic jet lag or shift work is deleterious to human metabolic health, in that such circadian desynchronization is associated with being overweight and the prevalence of altered glucose metabolism. Similar metabolic changes are observed with age, suggesting that chronic jet lag and accelerated cell aging are intimately related, but the association remains to be determined. We addressed whether jet lag induces metabolic and cell aging impairments in young grass rats (2-3 mo old), using control old grass rats (12-18 mo old) as an aging reference. Desynchronized young and control old subjects had impaired glucose tolerance (+60 and +280%) when compared with control young animals. Despite no significant variation in liver DNA damage, shorter telomeres were characterized, not only in old animal liver cells (-18%), but also at an intermediate level in desynchronized young rats (-9%). The same pattern was found for deacetylase sirtuin (SIRT)-1 (-57 and -29%), confirming that jet-lagged young rats have an intermediate aging profile. Our data indicate that an experimental circadian desynchronization in young animals is associated with a precocious aging profile based on 3 well-known markers, as well as a prediabetic phenotype. Such chronic jet lag-induced alterations observed in a diurnal species constitute proof of principle of the need to develop preventive treatments in jet-lagged persons and shift workers.
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Affiliation(s)
- Edith Grosbellet
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Sandrine Zahn
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Mathilde Arrivé
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Stéphanie Dumont
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Sylviane Gourmelen
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Paul Pévet
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - Etienne Challet
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
| | - François Criscuolo
- *Institute of Cellular and Integrative Neurosciences, Unité Propres de Recherche 3212, and Department of Ecology, Physiology, and Ethology, Hubert Curien Pluridisciplinary Institute, Unité Mixte de Recherche 7178, Centre National de la Recherche Scientifique, University of Strasbourg, Strasbourg, France
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21
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Abstract
Human aging is associated with increasing frailty and morbidity which can result in significant disability. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to aging-related diseases like depression, cognitive deficits, and Alzheimer's disease in some older individuals. In addition to neuro-cognitive dysfunction, it has also been associated with declining physical performance possibly due to sarcopenia. This article reviews the pathophysiology of HPA dysfunction with respect to increased basal adrenocorticotropic hormone (ACTH) and cortisol secretion, decreased glucocorticoid (GC) negative feedback at the level of the paraventricular nucleus (PVN) of the hypothalamus, hippocampus (HC), and prefrontal cortex (PFC), and flattening of diurnal pattern of cortisol release. It is possible that the increased cortisol secretion is secondary to peripheral conversion from cortisone. There is a decline in pregnolone secretion and C-19 steroids (DHEA) with aging. There is a small decrease in aldosterone with aging, but a subset of the older population have a genetic predisposition to develop hyperaldosteronism due to the increased ACTH stimulation. The understanding of the HPA axis and aging remains a complex area with conflicting studies leading to controversial interpretations.
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Affiliation(s)
- Deepashree Gupta
- Division of Endocrinology, Saint Louis University, Missouri, St. Louis; Divisions of Endocrinology and Geriatric Medicine, Saint Louis University, Missouri, St. Louis
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Boleij H, Willems J, Leijten M, Klooster JV, Lesscher H, Kirchhoff S, Lavrijsen M, Arndt SS, Ohl F. Chronic social stress does not affect behavioural habituation in male CD1 mice. Behav Brain Res 2014; 273:34-44. [DOI: 10.1016/j.bbr.2014.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 07/07/2014] [Accepted: 07/09/2014] [Indexed: 12/29/2022]
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Mulder CK, Papantoniou C, Gerkema MP, Van Der Zee EA. Neither the SCN nor the adrenals are required for circadian time-place learning in mice. Chronobiol Int 2014; 31:1075-92. [PMID: 25083974 PMCID: PMC4219850 DOI: 10.3109/07420528.2014.944975] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
During Time-Place Learning (TPL), animals link biological significant events (e.g. encountering predators, food, mates) with the location and time of occurrence in the environment. This allows animals to anticipate which locations to visit or avoid based on previous experience and knowledge of the current time of day. The TPL task applied in this study consists of three daily sessions in a three-arm maze, with a food reward at the end of each arm. During each session, mice should avoid one specific arm to avoid a foot-shock. We previously demonstrated that, rather than using external cue-based strategies, mice use an internal clock (circadian strategy) for TPL, referred to as circadian TPL (cTPL). It is unknown in which brain region(s) or peripheral organ(s) the consulted clock underlying cTPL resides. Three candidates were examined in this study: (a) the suprachiasmatic nucleus (SCN), a light entrainable oscillator (LEO) and considered the master circadian clock in the brain, (b) the food entrainable oscillator (FEO), entrained by restricted food availability, and (c) the adrenal glands, harboring an important peripheral oscillator. cTPL performance should be affected if the underlying oscillator system is abruptly phase-shifted. Therefore, we first investigated cTPL sensitivity to abrupt light and food shifts. Next we investigated cTPL in SCN-lesioned- and adrenalectomized mice. Abrupt FEO phase-shifts (induced by advancing and delaying feeding time) affected TPL performance in specific test sessions while a LEO phase-shift (induced by a light pulse) more severely affected TPL performance in all three daily test sessions. SCN-lesioned mice showed no TPL deficiencies compared to SHAM-lesioned mice. Moreover, both SHAM- and SCN-lesioned mice showed unaffected cTPL performance when re-tested after bilateral adrenalectomy. We conclude that, although cTPL is sensitive to timing manipulations with light as well as food, neither the SCN nor the adrenals are required for cTPL in mice.
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24
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Albrecht A, Thiere M, Bergado-Acosta JR, Poranzke J, Müller B, Stork O. Circadian modulation of anxiety: a role for somatostatin in the amygdala. PLoS One 2013; 8:e84668. [PMID: 24376834 PMCID: PMC3869835 DOI: 10.1371/journal.pone.0084668] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/18/2013] [Indexed: 12/30/2022] Open
Abstract
Pharmacological evidence suggests that the neuropeptide somatostatin (SST) exerts anxiolytic action via the amygdala, but findings concerning the putative role of endogenous SST in the regulation of emotional responses are contradictory. We hypothesized that an endogenous regulation of SST expression over the course of the day may determine its function and tested both SST gene expression and the behavior of SST knock out (SST-/-) mice in different aversive tests in relation to circadian rhythm. In an open field and a light/dark avoidance test, SST-/- mice showed significant hyperactivity and anxiety-like behavior during the second, but not during the first half of the active phase, failing to show the circadian modulation of behavior that was evident in their wild type littermates. Behavioral differences occurred independently of changes of intrinsically motivated activity in the home cage. A circadian regulation of SST mRNA and protein expression that was evident in the basolateral complex of the amygdala of wild type mice may provide a neuronal substrate for the observed behavior. However, fear memory towards auditory cue or the conditioning context displayed neither a time- nor genotype-dependent modulation. Together this indicates that SST, in a circadian manner and putatively via its regulation of expression in the amygdala, modulates behavior responding to mildly aversive conditions in mice.
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Affiliation(s)
- Anne Albrecht
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- * E-mail:
| | - Marlen Thiere
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Jorge Ricardo Bergado-Acosta
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Janine Poranzke
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Bettina Müller
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Center for Behavioural Brain Science, Magdeburg, Germany
| | - Oliver Stork
- Department of Genetics & Molecular Neurobiology, Institute of Biology, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- Center for Behavioural Brain Science, Magdeburg, Germany
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25
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Harris BN, Saltzman W. Effects of aging on hypothalamic-pituitary-adrenal (HPA) axis activity and reactivity in virgin male and female California mice (Peromyscus californicus). Gen Comp Endocrinol 2013; 186:41-9. [PMID: 23458287 PMCID: PMC3640751 DOI: 10.1016/j.ygcen.2013.02.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 01/21/2013] [Accepted: 02/14/2013] [Indexed: 11/22/2022]
Abstract
Life history theory posits that organisms face a trade-off between current and future reproductive attempts. The physiological mechanisms mediating such trade-offs are still largely unknown, but glucocorticoid hormones are likely candidates as elevated, post-stress glucocorticoid levels have been shown to suppress both reproductive physiology and reproductive behavior. Aged individuals have a decreasing window in which to reproduce, and are thus predicted to invest more heavily in current as opposed to future reproduction. Therefore, if glucocorticoids are important in mediating the trade-off between current and future reproduction, aged animals are expected to show decreased hypothalamic-pituitary-adrenal (HPA) axis responses to stressors and to stimulation by corticotropin-releasing hormone (CRH), and enhanced responses to glucocorticoid negative feedback, as compared to younger animals. We tested this hypothesis in the monogamous, biparental California mouse by comparing baseline and post-stress corticosterone levels, as well as corticosterone responses to dexamethasone (DEX) and CRH injections, between old (∼18-20months) and young (∼4months) virgin adults of both sexes. We also measured gonadal and uterine masses as a proxy for investment in potential current reproductive effort. Adrenal glands were weighed to determine if older animal had decreased adrenal mass. Old male mice had lower plasma corticosterone levels 8h after DEX injection than did young male mice, suggesting that the anterior pituitary of older males is more sensitive to DEX-induced negative feedback. Old female mice had higher body-mass-corrected uterine mass than did young females. No other differences in corticosterone levels or organ masses were found between age groups within either sex. In conclusion, we did not find strong evidence for age-related change in HPA activity or reactivity in virgin adult male or female California mice; however, future studies investigating HPA activity and reproductive outcomes in young and old breeding adults would be illuminating.
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Affiliation(s)
- Breanna N Harris
- Department of Biology, University of California, Riverside, CA 92521, USA.
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Chronic social stress during adolescence: interplay of paroxetine treatment and ageing. Neuropharmacology 2013; 72:38-46. [PMID: 23602985 DOI: 10.1016/j.neuropharm.2013.03.035] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 02/18/2013] [Accepted: 03/05/2013] [Indexed: 12/16/2022]
Abstract
Exposure to chronic stress during developmental periods is a risk factor for a number of psychiatric disorders. While the direct effects of stress exposure have been studied extensively, little is known about the long-lasting effects and the interaction with ageing. The same holds true for the treatment with selective serotonin reuptake inhibitors (SSRIs), which have been shown to prevent or reverse some stress-induced effects. Here, we studied the direct and long-lasting impact of chronic social stress during adolescence and the impact of chronic treatment with the SSRI paroxetine in adulthood and aged animals. Therefore, male CD1 mice at the age of 28 days were subjected to 7 weeks of chronic social stress. Treatment with paroxetine was performed per os with a dosage of 20 mg/g BW. We were able to reverse most of the effects of chronic social stress in adult mice (4 months old) and to some extend in aged animals (15 months old) with the SSRI treatment. Especially the regulation of the HPA axis seems to be affected in aged mice with a shift to the use of vasopressin. Our results demonstrate that chronic stress exposure and antidepressant treatment at the end of the developmental period can have a significant and long-lasting impact, highly relevant for healthy ageing.
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27
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Watching the clock and hitting the snooze button: introduction to the special issue on circadian rhythms and sleep in neurological disorders. Exp Neurol 2013; 243:1-3. [PMID: 23399891 DOI: 10.1016/j.expneurol.2013.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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28
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Long-lasting increase of corticosterone after fear memory reactivation: anxiolytic effects and network activity modulation in the ventral hippocampus. Neuropsychopharmacology 2013; 38:386-94. [PMID: 22968818 PMCID: PMC3547189 DOI: 10.1038/npp.2012.192] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Pathological fear and anxiety can be studied, in rodents, with fear conditioning and exposure to reminder cues. These paradigms are thought to critically involve the ventral hippocampus, which also serves as key site of glucocorticoid action in the brain. Here, we demonstrate a long-lasting reduction of kainate-induced gamma oscillations in slice preparations of the ventral hippocampal area CA3, 30 days after a single fear conditioning training. Reduction of gamma power was sensitive to corticosterone application and associated with a decrease in glucocorticoid and mineralocorticoid receptor mRNA expression across strata of the ventral hippocampal CA3. A fear reactivation session 24 h after the initial conditioning normalized receptor expression levels and attenuated the corticosterone-mediated recovery of gamma oscillations. It moreover increased both baseline and stimulus-induced corticosterone plasma levels and evoked a generalization of fear memory to the background context. Reduced ventral hippocampal gamma oscillation in both fear reactivated and non-reactivated mice were associated with a decrease of anxiety-like behavior in an elevated plus maze. Taking advantage of the circadian fluctuation in corticosterone, we demonstrated the association of high endogenous basal corticosterone plasma concentrations during morning hours with reduced anxiety-like behavior in fear reactivated mice. The anxiolytic effect of the hormone was verified with local applications to the ventral hippocampus. Our data suggest that corticosterone acting on ventral hippocampal network activity has anxiolytic-like effects following fear exposure, highlighting its potential therapeutic value for anxiety disorders.
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Evans JF, Islam S, Urade Y, Eguchi N, Ragolia L. The lipocalin-type prostaglandin D2 synthase knockout mouse model of insulin resistance and obesity demonstrates early hypothalamic-pituitary-adrenal axis hyperactivity. J Endocrinol 2013; 216:169-80. [PMID: 23151358 DOI: 10.1530/joe-12-0275] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Obesity and diabetes are closely associated with hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis. In this study, the diet-induced obese C57BL/6 mouse was used to test the hypothesis that chronically elevated metabolic parameters associated with the development of obesity such as cholesterol and glucose can aggravate basal HPA axis activity. Because the lipocalin-type prostaglandin D(2) synthase (L-PGDS) knockout (KO) mouse is a model of accelerated insulin resistance, glucose intolerance, and obesity, it was further hypothesized that HPA activity would be greater in this model. Starting at 8 weeks of age, the L-PGDS KO and C57BL/6 mice were maintained on a low-fat or high-fat diet. After 20 or 37 weeks, fasting metabolic parameters and basal HPA axis hormones were measured and compared between genotypes. Correlation analyses were performed to identify associations between obesity-related chronic metabolic changes and changes in the basal activity of the HPA axis. Our results have identified strong positive correlations between total cholesterol, LDL-cholesterol, glucose, and HPA axis hormones that increase with age in the C57BL/6 mice. These data confirm that obesity-related elevations in cholesterol and glucose can heighten basal HPA activity. Additionally, the L-PGDS KO mice show early elevations in HPA activity with no age-related changes relative to the C57BL/6 mice.
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Affiliation(s)
- Jodi F Evans
- Biomedical Research Core, Winthrop University Hospital, 222 Station Plaza North, Suite 505-B, Mineola, New York 11501, USA
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Coomans CP, van den Berg SAA, Houben T, van Klinken JB, van den Berg R, Pronk ACM, Havekes LM, Romijn JA, van Dijk KW, Biermasz NR, Meijer JH. Detrimental effects of constant light exposure and high-fat diet on circadian energy metabolism and insulin sensitivity. FASEB J 2013; 27:1721-32. [PMID: 23303208 DOI: 10.1096/fj.12-210898] [Citation(s) in RCA: 181] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Circadian rhythm disturbances are observed in, e.g., aging and neurodegenerative diseases and are associated with an increased incidence of obesity and diabetes. We subjected male C57Bl/6J mice to constant light [12-h light-light (LL) cycle] to examine the effects of a disturbed circadian rhythm on energy metabolism and insulin sensitivity. In vivo electrophysiological recordings in the central pacemaker of the suprachiasmatic nuclei (SCN) revealed an immediate reduction in rhythm amplitude, stabilizing at 44% of normal amplitude values after 4 d LL. Food intake was increased (+26%) and energy expenditure decreased (-13%), and we observed immediate body weight gain (d 4: +2.4%, d 14: +5.0%). Mixed model analysis revealed that weight gain developed more rapidly in response to LL as compared to high fat. After 4 wk in LL, the circadian pattern in feeding and energy expenditure was completely lost, despite continuing low-amplitude rhythms in the SCN and in behavior, whereas weight gain had stabilized. Hyperinsulinemic-euglycemic clamp analysis revealed complete abolishment of normal circadian variation in insulin sensitivity in LL. In conclusion, a reduction in amplitude of the SCN, to values previously observed in aged mice, is sufficient to induce a complete loss of circadian rhythms in energy metabolism and insulin sensitivity.
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Affiliation(s)
- Claudia P Coomans
- Leiden University Medical Center, Department of Molecular Cell Biology, Laboratory of Neurophysiology, Bldg. 2, Room T5-32, Einthovenweg 20, PO Box 9600, 2300 RC Leiden, the Netherlands.
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Harris BN, Saltzman W, de Jong TR, Milnes MR. Hypothalamic-pituitary-adrenal (HPA) axis function in the California mouse (Peromyscus californicus): Changes in baseline activity, reactivity, and fecal excretion of glucocorticoids across the diurnal cycle. Gen Comp Endocrinol 2012; 179:436-50. [PMID: 23026495 PMCID: PMC3513568 DOI: 10.1016/j.ygcen.2012.08.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Revised: 07/07/2012] [Accepted: 08/13/2012] [Indexed: 11/18/2022]
Abstract
The California mouse, Peromyscus californicus, is an increasingly popular animal model in behavioral, neural, and endocrine studies, but little is known about its baseline hypothalamic-pituitary-adrenal (HPA) axis activity or HPA responses to stressors. We characterized plasma corticosterone (CORT) concentrations in P. californicus under baseline conditions across the diurnal cycle, in response to pharmacological manipulation of the HPA axis, and in response to a variety of stressors at different times of day. In addition, we explored the use of fecal samples to monitor adrenocortical activity non-invasively. California mice have very high baseline levels of circulating CORT that change markedly over 24h, but that do not differ between the sexes. This species may be somewhat glucocorticoid-resistant in comparison to other rodents as a relatively high dose of dexamethasone (5mg/kg, s.c.) was required to suppress plasma CORT for 8h post-injection. CORT responses to stressors and ACTH injection differed with time of day, as CORT concentrations were elevated more readily during the morning (inactive period) than in the evening (active period) when compared to time-matched control. Data from (3)H-CORT injection studies show that the time course for excretion of fecal CORT, or glucocorticoid metabolites, differs with time of injection. Mice injected in the evening excreted the majority of fecal radioactivity 2-4h post-injection whereas mice injected during the morning did so at 14-16h post-injection. Unfortunately, the antibody we used does not adequately bind the most prevalent fecal glucocorticoid metabolites and therefore we could not validate its use for fecal assays.
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Affiliation(s)
- Breanna N Harris
- Department of Biology, University of California, Riverside, CA 92521, USA.
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Stress or no stress: Mineralocorticoid receptors in the forebrain regulate behavioral adaptation. Neurobiol Learn Mem 2012; 98:33-40. [DOI: 10.1016/j.nlm.2012.04.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/04/2012] [Accepted: 04/12/2012] [Indexed: 12/20/2022]
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Post-training reward partially restores chronic stress induced effects in mice. PLoS One 2012; 7:e39033. [PMID: 22745700 PMCID: PMC3382188 DOI: 10.1371/journal.pone.0039033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 05/15/2012] [Indexed: 01/28/2023] Open
Abstract
Reduced responsiveness to positive stimuli is a core symptom of depression, known as anhedonia. In the present study, we assessed the expression of anhedonia in our chronic stress mouse model using a subset of read-out parameters. In line with this, we investigated in how far chronic stress would affect the facilitating effect of post-training self-administration of sugar, as we previously observed in naïve mice. Male C57BL/6J mice were repeatedly and at unpredictable times exposed to rats (no physical contact) over the course of two weeks. Following novelty exploration, (non-) spatial learning and memory processes with and without post-training sugar acting as reinforcer, emotionality, reward sensitivity and corticosterone levels were determined. We found that (1) the effects of chronic stress persisted beyond the period of the actual rat exposure. (2) Post-training self-administration of sugar as reinforcer improved spatial performance in naïve mice, whereas (3) in stressed mice sugar partially “normalized” the impaired performance to the level of controls without sugar. Chronic stress (4) increased behavioral inhibition in response to novelty; (5) induced dynamic changes in the pattern of circadian corticosterone secretion during the first week after rat stress and (6) increased the intake of sucrose and water. (7) Chronic stress and sugar consumed during spatial training facilitated the memory for the location of the sucrose bottle weeks later. Concluding, our chronic stress paradigm induces the expression of anhedonia in mice, at different levels of behavior. The behavioral inhibition appears to be long lasting in stressed mice. Interestingly, sugar consumed in close context with spatial learning partially rescued the stress-induced emotional and cognitive impairments. This suggests that reward can ameliorate part of the negative consequences of chronic stress on memory.
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Social disruption stress increases IL-6 levels and accelerates atherosclerosis in ApoE-/- mice. Atherosclerosis 2011; 221:359-65. [PMID: 22284955 DOI: 10.1016/j.atherosclerosis.2011.11.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 11/08/2011] [Accepted: 11/16/2011] [Indexed: 01/28/2023]
Abstract
INTRODUCTION We have previously shown that different forms of stress have distinctive effects on atherogenesis in mice. We showed that social stress increase atherosclerosis in ApoE(-/-) mice, while more physical forms of stress do not. Here we evaluated the effect of social disruption (SDR) stress on atherogenesis and evaluated cytokine release after SDR-stress and five more physical stressors. METHODS Male ApoE(-/-) mice were exposed to SDR-stress during 12 weeks, and atherosclerotic plaque area was assessed in aorta, aortic root and innominate artery. Further, male C57BL/6 mice were exposed to SDR-stress or five physical stressors, and cytokine and corticosterone levels were analyzed in plasma/serum samples immediately after stress. RESULTS We found a correlation between the level of SDR-stress and atherosclerotic plaque area in aorta and a numerical increased plaque area in aortic root. SDR stress did not affect histological features of plaque composition. However, SDR-stress increased levels of corticosterone, IL-6 and CXCL1. Plasma corticosterone increased for all five physical stressors, but IL-6 and CXCL1 only increased in the group exposed to restraint combined with rat odor. CONCLUSIONS These findings suggest that SDR-stress is indeed atherogenic, in contrast to our previous results using the physical stressors. A possible explanation to this difference is that SDR-stress, but not physical stressors, leads to release of the pro-inflammatory cytokines IL-6 and CXCL1.
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Benedetti M, Merino R, Kusuda R, Ravanelli M, Cadetti F, dos Santos P, Zanon S, Lucas G. Plasma corticosterone levels in mouse models of pain. Eur J Pain 2011; 16:803-15. [DOI: 10.1002/j.1532-2149.2011.00066.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2011] [Indexed: 01/07/2023]
Affiliation(s)
- M. Benedetti
- Department of Neuroscience and Behaviour; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - R. Merino
- Department of Neuroscience and Behaviour; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - R. Kusuda
- Department of Physiology; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - M.I. Ravanelli
- Department of Physiology; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - F. Cadetti
- Department of Neuroscience and Behaviour; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - P. dos Santos
- Department of Neuroscience and Behaviour; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - S. Zanon
- Department of Physiology; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
| | - G. Lucas
- Department of Physiology; Ribeirão Preto School of Medicine; University of São Paulo; Av. Bandeirantes, 3900; Ribeirão Preto; SP; 14049-900; Brazil
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Son GH, Chung S, Kim K. The adrenal peripheral clock: glucocorticoid and the circadian timing system. Front Neuroendocrinol 2011; 32:451-65. [PMID: 21802440 DOI: 10.1016/j.yfrne.2011.07.003] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2010] [Revised: 04/25/2011] [Accepted: 07/06/2011] [Indexed: 12/27/2022]
Abstract
The mammalian circadian timing system is organized in a hierarchy, with the master clock residing in the suprachiasmatic nucleus (SCN) of the hypothalamus and subsidiary peripheral clocks in other brain regions as well as peripheral tissues. Since the local oscillators in most cells contain a similar molecular makeup to that in the central pacemaker, determining the role of the peripheral clocks in the regulation of rhythmic physiology and behavior is an important issue. Glucocorticoids (GCs) are a class of multi-functional adrenal steroid hormones, which exhibit a robust circadian rhythm, with a peak linked with the onset of the daily activity phase. It has long been believed that the production and secretion of GC is primarily governed through the hypothalamus-pituitary-adrenal (HPA) neuroendocrine axis in mammals. Growing evidence, however, strongly supports the notion that the periodicity of GC involves the integrated activity of multiple regulatory mechanisms related to circadian timing system along with the classical HPA neuroendocrine regulation. The adrenal-intrinsic oscillator as well as the central pacemaker plays a pivotal role in its rhythmicity. GC influences numerous biological processes, such as metabolic, cardiovascular, immune and even higher brain functions, and also acts as a resetting signal for the ubiquitous peripheral clocks, suggesting its importance in harmonizing circadian physiology and behavior. In this review, we will therefore focus on the recent advances in our understanding of the circadian regulation of adrenal GC and its functional relevance.
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Affiliation(s)
- Gi Hoon Son
- Department of Biological Sciences, Seoul National University, Brain Research Center for the 21st Century Frontier Program in Neuroscience, Seoul 151-742, Republic of Korea
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Rothman SM, Herdener N, Camandola S, Texel SJ, Mughal MR, Cong WN, Martin B, Mattson MP. 3xTgAD mice exhibit altered behavior and elevated Aβ after chronic mild social stress. Neurobiol Aging 2011; 33:830.e1-12. [PMID: 21855175 DOI: 10.1016/j.neurobiolaging.2011.07.005] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2011] [Revised: 06/30/2011] [Accepted: 07/08/2011] [Indexed: 01/01/2023]
Abstract
Chronic stress may be a risk factor for developing Alzheimer's disease (AD), but most studies of the effects of stress in models of AD utilize acute adverse stressors of questionable clinical relevance. The goal of this work was to determine how chronic psychosocial stress affects behavioral and pathological outcomes in an animal model of AD, and to elucidate underlying mechanisms. A triple-transgenic mouse model of AD (3xTgAD mice) and nontransgenic control mice were used to test for an affect of chronic mild social stress on blood glucose, plasma glucocorticoids, plasma insulin, anxiety, and hippocampal amyloid β-particle (Aβ), phosphorylated tau (ptau), and brain-derived neurotrophic factor (BDNF) levels. Despite the fact that both control and 3xTgAD mice experienced rises in corticosterone during episodes of mild social stress, at the end of the 6-week stress period 3xTgAD mice displayed increased anxiety, elevated levels of Aβ oligomers and intraneuronal Aβ, and decreased brain-derived neurotrophic factor levels, whereas control mice did not. Findings suggest 3xTgAD mice are more vulnerable than control mice to chronic psychosocial stress, and that such chronic stress exacerbates Aβ accumulation and impairs neurotrophic signaling.
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Affiliation(s)
- Sarah M Rothman
- Laboratory of Neurosciences, National Institute on Aging, Intramural Research Program, National Institutes of Health, Baltimore, MD 21224, USA
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Chung S, Son GH, Kim K. Circadian rhythm of adrenal glucocorticoid: Its regulation and clinical implications. Biochim Biophys Acta Mol Basis Dis 2011; 1812:581-91. [DOI: 10.1016/j.bbadis.2011.02.003] [Citation(s) in RCA: 154] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 01/31/2011] [Accepted: 02/07/2011] [Indexed: 10/18/2022]
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Schenk GJ, Vreugdenhil E, Hubens CJY, Veldhuisen B, de Kloet ER, Oitzl MS. Hippocampal CARP over-expression solidifies consolidation of contextual fear memories. Physiol Behav 2010; 102:323-31. [PMID: 21130104 DOI: 10.1016/j.physbeh.2010.11.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/15/2010] [Accepted: 11/18/2010] [Indexed: 01/13/2023]
Abstract
The Doublecortin-Like Kinase (DCLK) gene is involved in neuronal migration during development. Through alternative splicing the DCLK gene also produces a transcript called Ca(2+)/calmodulin dependent protein kinase (CaMK)-related peptide (CARP) that is expressed exclusively during adulthood in response to neuronal activity. The function of CARP, however, is poorly understood. To study CARP function, we have generated transgenic mice with over-expression of the CARP transcript in, amongst other brain areas, the hippocampus. We aimed to characterize possible behavioral adaptations of these mice by using a Pavlovian fear conditioning approach. This type of fear conditioning, in which both the hippocampus and amygdala are critically involved, allows studying the formation and extinction of fear related memories. We here report on the behavioral adaptations of two distinct transgenic lines: one with high levels of CARP in the hippocampus and amygdala, whilst the other has high levels of CARP in the hippocampal formation, but not in the amygdala. We tested both mouse lines separately by comparing them to their wild-type littermate controls. We provide evidence suggesting consolidation of contextual fear memories is strengthened in mice of both transgenic lines.
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Affiliation(s)
- Geert J Schenk
- Division of Medical Pharmacology, Leiden/Amsterdam Centre for Drug Research, Einsteinweg 55, 2333 CC Leiden, The Netherlands.
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Beynon AL, Coogan AN. DIURNAL, AGE, AND IMMUNE REGULATION OF INTERLEUKIN-1β AND INTERLEUKIN-1 TYPE 1 RECEPTOR IN THE MOUSE SUPRACHIASMATIC NUCLEUS. Chronobiol Int 2010; 27:1546-63. [DOI: 10.3109/07420528.2010.501927] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Amy L. Beynon
- Neuroscience and Molecular Psychiatry, Institute of Life Science, School of Medicine, Swansea University, Swansea, United Kingdom
| | - Andrew N. Coogan
- Neuroscience and Molecular Psychiatry, Institute of Life Science, School of Medicine, Swansea University, Swansea, United Kingdom
- Department of Psychology, National University of Ireland Maynooth, Maynooth, Co. Kildare, Republic of Ireland
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Fraulob JC, Ogg-Diamantino R, Fernandes-Santos C, Aguila MB, Mandarim-de-Lacerda CA. A Mouse Model of Metabolic Syndrome: Insulin Resistance, Fatty Liver and Non-Alcoholic Fatty Pancreas Disease (NAFPD) in C57BL/6 Mice Fed a High Fat Diet. J Clin Biochem Nutr 2010; 46:212-23. [PMID: 20490316 PMCID: PMC2872226 DOI: 10.3164/jcbn.09-83] [Citation(s) in RCA: 311] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/23/2009] [Indexed: 12/12/2022] Open
Abstract
Diet-induced obesity in C57BL/6 mice triggers common features of human metabolic syndrome (MetS). The purpose is to assess the suitability of a diet-induced obesity model for investigating non-alcoholic fatty pancreatic disease (NAFPD), fatty liver and insulin resistance. Adult C57BL/6 mice were fed either high-fat chow (HFC, 60% fat) or standard chow (SC, 10% fat) during a 16-week period. We evaluated in both groups: hepatopancreatic injuries, pancreatic islets size, alpha and beta-cell immunodensities, intraperitoneal insulin tolerance test (IPITT) and oral glucose tolerance test (OGTT). The HFC mice displayed greater mass gain (p<0.0001) and total visceral fat pads (p<0.001). OGTT showed impairment of glucose clearance in HFC mice (p<0.0001). IPITT revealed insulin resistance in HFC mice (p<0.0001). The HFC mice showed larger pancreatic islet size and significantly greater alpha and beta-cell immunodensities than SC mice. Pancreas and liver from HFC were heavier and contained higher fat concentration. In conclusion, C57BL/6 mice fed a high-fat diet develop features of NAFPD. Insulin resistance and ectopic accumulation of hepatic fat are well known to occur in MetS. Additionally, the importance of fat accumulation in the pancreas has been recently highlighted. Therefore, this model could help to elucidate target organ alterations associated with metabolic syndrome.
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Affiliation(s)
- Julio C Fraulob
- Laboratory of Morphometry and Cardiovascular Morphology, Biomedical Center, Institute of Biology, State University of Rio de Janeiro, Av 28 de Setembro, 87 (fds) - CEP 20551-030, Rio de Janeiro, Brazil
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Sarrazin N, Di Blasi F, Roullot-Lacarrière V, Rougé-Pont F, Le Roux A, Costet P, Revest JM, Piazza PV. Transcriptional effects of glucocorticoid receptors in the dentate gyrus increase anxiety-related behaviors. PLoS One 2009; 4:e7704. [PMID: 19888328 PMCID: PMC2765620 DOI: 10.1371/journal.pone.0007704] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 10/12/2009] [Indexed: 12/24/2022] Open
Abstract
The Glucocorticoid Receptor (GR) is a transcription factor ubiquitously expressed in the brain. Activation of brain GRs by high levels of glucocorticoid (GC) hormones modifies a large variety of physiological and pathological-related behaviors. Unfortunately the specific cellular targets of GR-mediated behavioral effects of GC are still largely unknown. To address this issue, we generated a mutated form of the GR called ΔGR. ΔGR is a constitutively transcriptionally active form of the GR that is localized in the nuclei and activates transcription without binding to glucocorticoids. Using the tetracycline-regulated system (Tet-OFF), we developed an inducible transgenic approach that allows the expression of the ΔGR in specific brain areas. We focused our study on a mouse line that expressed ΔGR almost selectively in the glutamatergic neurons of the dentate gyrus (DG) of the hippocampus. This restricted expression of the ΔGR increased anxiety-related behaviors without affecting other behaviors that could indirectly influence performance in anxiety-related tests. This behavioral phenotype was also associated with an up-regulation of the MAPK signaling pathway and Egr-1 protein in the DG. These findings identify glutamatergic neurons in the DG as one of the cellular substrate of stress-related pathologies.
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Affiliation(s)
- Nadège Sarrazin
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Francesco Di Blasi
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
- Istituto di Biomedicina e di Immunologia Molecolare, CNR, Palermo, Italy
| | - Valérie Roullot-Lacarrière
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Françoise Rougé-Pont
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Anne Le Roux
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
| | - Pierre Costet
- Université de Bordeaux, Bordeaux, France
- Transgenesis Laboratory, Université de Bordeaux, Bordeaux, France
| | - Jean-Michel Revest
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
- * E-mail: (JMR); (PVP)
| | - Pier Vincenzo Piazza
- Pathophysiology of Addiction group, Neurocenter Magendie, INSERM U862, Bordeaux, France
- Université de Bordeaux, Bordeaux, France
- * E-mail: (JMR); (PVP)
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Repeated exposure to stressors do not accelerate atherosclerosis in ApoE−/− mice. Atherosclerosis 2009; 204:90-5. [DOI: 10.1016/j.atherosclerosis.2008.08.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Revised: 08/14/2008] [Accepted: 08/17/2008] [Indexed: 11/21/2022]
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Effects of a fire alarm strobe light on fecal corticosterone metabolite concentrations in mice. Lab Anim (NY) 2009; 38:61-8. [DOI: 10.1038/laban0209-61] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 11/05/2008] [Indexed: 11/08/2022]
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Touma C, Fenzl T, Ruschel J, Palme R, Holsboer F, Kimura M, Landgraf R. Rhythmicity in mice selected for extremes in stress reactivity: behavioural, endocrine and sleep changes resembling endophenotypes of major depression. PLoS One 2009; 4:e4325. [PMID: 19177162 PMCID: PMC2627900 DOI: 10.1371/journal.pone.0004325] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 11/26/2008] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, including hyper- or hypo-activity of the stress hormone system, plays a critical role in the pathophysiology of mood disorders such as major depression (MD). Further biological hallmarks of MD are disturbances in circadian rhythms and sleep architecture. Applying a translational approach, an animal model has recently been developed, focusing on the deviation in sensitivity to stressful encounters. This so-called 'stress reactivity' (SR) mouse model consists of three separate breeding lines selected for either high (HR), intermediate (IR), or low (LR) corticosterone increase in response to stressors. METHODOLOGY/PRINCIPLE FINDINGS In order to contribute to the validation of the SR mouse model, our study combined the analysis of behavioural and HPA axis rhythmicity with sleep-EEG recordings in the HR/IR/LR mouse lines. We found that hyper-responsiveness to stressors was associated with psychomotor alterations (increased locomotor activity and exploration towards the end of the resting period), resembling symptoms like restlessness, sleep continuity disturbances and early awakenings that are commonly observed in melancholic depression. Additionally, HR mice also showed neuroendocrine abnormalities similar to symptoms of MD patients such as reduced amplitude of the circadian glucocorticoid rhythm and elevated trough levels. The sleep-EEG analyses, furthermore, revealed changes in rapid eye movement (REM) and non-REM sleep as well as slow wave activity, indicative of reduced sleep efficacy and REM sleep disinhibition in HR mice. CONCLUSION/SIGNIFICANCE Thus, we could show that by selectively breeding mice for extremes in stress reactivity, clinically relevant endophenotypes of MD can be modelled. Given the importance of rhythmicity and sleep disturbances as biomarkers of MD, both animal and clinical studies on the interaction of behavioural, neuroendocrine and sleep parameters may reveal molecular pathways that ultimately lead to the discovery of new targets for antidepressant drugs tailored to match specific pathologies within MD.
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Affiliation(s)
- Chadi Touma
- Max Planck Institute of Psychiatry, Munich, Germany.
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Repeated rat exposure inhibits the circadian activity patterns of C57BL/6J mice in the home cage. Behav Brain Res 2009; 196:84-92. [DOI: 10.1016/j.bbr.2008.07.035] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2008] [Revised: 07/15/2008] [Accepted: 07/17/2008] [Indexed: 11/19/2022]
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Yi SS, Hwang IK, Chun MS, Kim YN, Kim IY, Lee IS, Seong JK, Yoon YS. Glucocorticoid receptor changes associate with age in the paraventricular nucleus of type II diabetic rat model. Neurochem Res 2008; 34:851-8. [PMID: 18758953 DOI: 10.1007/s11064-008-9836-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 08/12/2008] [Indexed: 12/25/2022]
Abstract
Diabetes is a metabolic disorder that is associated with the dysregulation of a number of systems within the body. In the present study, we investigated glucocorticoid receptor (GR) immunoreactivity and its protein levels in the paraventricular nuclei of 4-, 12-, 20- and 30-week-old Zucker diabetic fatty (fa/fa, ZDF) and in Zucker lean control (fa/+ or +/+, ZLC) rats, because the progressive induction of diabetes is detectable in this model after 7 weeks of age and chronic diabetic conditions are maintained after 12 weeks of age. GR immunoreactivity was detected in parvocellular paraventricular nuclei and this and GR protein levels were exponentially increased according to the ages. In particular, GR immunoreactivities and protein levels were markedly more increased in 30-week-old ZDF rats than in age-matched ZLC group and in younger ZDF group. The present study suggests that GR immunoreactivity and its protein level is associated with a degenerative phenotype in the hypothalamus of from 12-weeks old in the ZDF rat type II diabetes model.
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Affiliation(s)
- Sun Shin Yi
- Department of Anatomy and Cell Biology, College of Veterinary Medicine and BK21 Program for Veterinary Science, Seoul National University, Seoul, South Korea
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Pilorz V, Steinlechner S, Oster H. Age and oestrus cycle-related changes in glucocorticoid excretion and wheel-running activity in female mice carrying mutations in the circadian clock genes Per1 and Per2. Physiol Behav 2008; 96:57-63. [PMID: 18786554 DOI: 10.1016/j.physbeh.2008.08.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 08/12/2008] [Accepted: 08/14/2008] [Indexed: 10/21/2022]
Abstract
In mammals, numerous physiological and behavioural functions are controlled by an endogenous circadian clock located in the suprachiasmatic nuclei (SCN). Within the SCN neurons, clock genes such as Per1 and Per2 interact in a molecular clockwork regulating the expression of hundreds of output genes. Through the timed release of humoral and neuronal signals, the rhythmicity of numerous biological processes, including reproductive behaviour, the oestrus cycle and endocrine parameters is controlled by the SCN. Mutations in Per genes in mice affect a wide array of physiological functions. Interestingly, most of these studies use only male animals, thus neglecting potential gender-specificities in clock function. In an attempt to broaden this perspective we have investigated the impact of Per1 and Per2 mutations on both glucocorticoid (GC) metabolite excretion and locomotor activity in relation to age and oestrus cycle stage of female mice. We show that the Per2 mutation dampens daily GC rhythms in young adult females. While locomotor activity does not vary along the different oestrus stages in Per2 mutant females, oestrus effects on GC excretion and locomotor activity are largely comparable between Per1 mutants and wild-type animals. 20 month-old, acyclic Per1 and wild-type females show reduced GC levels when compared to young adults while aged Per2 mutants retain their normal GC rhythmicity. Correlating with this, onsets of locomotor activity do not change with age in Per2 mutant females. Together, our data highlight specific roles for Per1 and Per2 in both the regulation of locomotor activity and endocrine functions in the female organism.
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Affiliation(s)
- Violetta Pilorz
- Department of Zoology, University of Veterinary Medicine Hannover, Hanover, Germany.
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Stranahan AM, Lee K, Mattson MP. Contributions of impaired hippocampal plasticity and neurodegeneration to age-related deficits in hormonal pulsatility. Ageing Res Rev 2008; 7:164-76. [PMID: 18262476 DOI: 10.1016/j.arr.2007.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
Abstract
Connectivity between the hippocampus and hypothalamus plays an essential role in circadian rhythmicity and stress responsiveness. Both hippocampal dysfunction and loss of hormonal pulsatility have been demonstrated in aged animals, but the possibility of a functional interaction between these two processes remains unexplored. Correlated hippocampal neuropathology and flattening of the circadian rhythms occur in the elderly, and we propose that these processes are causally linked. In this review, we discuss the anatomical and functional nature of hippocampal interconnections with the hypothalamus. We also discuss the results of studies exploring the relationship between circadian phase and hippocampal plasticity in young animals, with the goal of understanding how these mechanisms might be restored in the aging brain.
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Qin M, Smith CB. Unaltered hormonal response to stress in a mouse model of fragile X syndrome. Psychoneuroendocrinology 2008; 33:883-9. [PMID: 18479837 PMCID: PMC2615669 DOI: 10.1016/j.psyneuen.2008.03.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 03/18/2008] [Accepted: 03/26/2008] [Indexed: 11/30/2022]
Abstract
Reports in the clinical literature and studies of fmr1 knockout mice have led to the hypothesis that, in addition to mental retardation, fragile X syndrome is characterized by a dysregulation of hypothalamic-pituitary-adrenal axis function. We have systematically examined this hypothesis by studying the effects of stress on adrenocorticotrophic hormone and corticosterone levels in adult, male fmr1 knockout mice. Initially we determined the circadian rhythms of the plasma hormone levels in both wild-type and fmr1 knockout mice and established the optimal time to impose the stress. We found no genotypic differences in the circadian rhythms of either hormone. We studied two types of stressors, immobilization and spatial novelty; spatial novelty was 5min in an elevated plus-maze. We varied the duration of immobilization and followed the time course of recovery of hormones to their pre-stress levels. Despite the lower anxiety exhibited by fmr1 knockout mice in the elevated plus-maze, hormonal responses to and recovery from this spatial novelty were similar in both genotypes. Further, we found no genotypic differences in hormonal responses to immobilization stress. The results of our study indicate that, in FVB/NJ mice, the hormonal response to and recovery from acute stress is unaltered by the lack of fragile X mental retardation protein.
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Affiliation(s)
| | - Carolyn Beebe Smith
- Corresponding author: Carolyn Beebe Smith, Unit on Neuroadaptation & Protein Metabolism, Laboratory of Cerebral Metabolism, Bldg. 10 2D54, 10 Center Drive, National Institutes of Health, Bethesda, MD 20892-1298, 301-402-3120 (telephone), 301-480-1668 (FAX), (e-mail)
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