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Boero G, Porcu P, Morrow AL. Pleiotropic actions of allopregnanolone underlie therapeutic benefits in stress-related disease. Neurobiol Stress 2019; 12:100203. [PMID: 31879693 PMCID: PMC6920111 DOI: 10.1016/j.ynstr.2019.100203] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/15/2019] [Accepted: 11/21/2019] [Indexed: 01/20/2023] Open
Abstract
For several years, research from around the world has suggested that the neuroactive steroid (3α,5α)-3-hydroxypregnan-20-one (allopregnanolone) may have therapeutic potential for treatment of various stress-related diseases including post-traumatic stress disorder (PTSD), depression, alcohol use disorders (AUDs), as well as neurological and psychiatric conditions that are worsened in the presence of stress, such as multiple sclerosis, schizophrenia, and seizure disorders. In this review, we make the argument that the pleiotropic actions of allopregnanolone account for its ability to promote recovery in such a wide variety of illnesses. Likewise, the allopregnanolone precursors, pregnenolone and progesterone, share many actions of allopregnanolone. Of course, pregnenolone and progesterone lack direct effects on GABAA receptors, but these compounds are converted to allopregnanolone in vivo. This review presents a theoretical framework for understanding how endogenous neurosteroids that regulate 1) γ-aminobutyric acid (GABA)A receptors, 2) corticotropin releasing factor (CRF) and 3) pro-inflammatory signaling in the innate immune system and brain could play a key role in both the prevention and treatment of stress-related disease. We further discuss cautions and limitations of allopregnanolone or precursor therapy as well as the need for more clinical studies.
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Affiliation(s)
- Giorgia Boero
- Department of Psychiatry, Department of Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, 27599, USA
| | - Patrizia Porcu
- Neuroscience Institute, National Research Council of Italy (CNR), Cagliari, Italy
| | - A Leslie Morrow
- Department of Psychiatry, Department of Pharmacology, Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, School of Medicine, Chapel Hill, NC, 27599, USA
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2
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Prescot A, Sheth C, Legarreta M, Renshaw PF, McGlade E, Yurgelun-Todd D. Altered Cortical GABA in Female Veterans with Suicidal Behavior: Sex Differences and Clinical Correlates. CHRONIC STRESS (THOUSAND OAKS, CALIF.) 2018; 2:2470547018768771. [PMID: 29756082 PMCID: PMC5947869 DOI: 10.1177/2470547018768771] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/14/2018] [Indexed: 11/21/2022]
Abstract
Background Suicide is a public health concern in the civilian and veteran populations. Stressful life events are precipitating factors for suicide. The neurochemical underpinnings of the association between stress/trauma and suicide risk are unclear, especially in regards to sex differences. We hypothesized that gamma-amino butyric acid (GABA), the major inhibitory neurotransmitter may be a neurochemical candidate that is critical in the association between stress and suicide risk in veterans. Methods Proton magnetic resonance spectroscopy (1H MRS) at 3.0 Tesla was used to measure in vivo neurochemistry in the anterior cingulate cortex (ACC; predominantly the dorsal ACC) of 81 veterans (16 females), including 57 (11 females) who endorsed past suicidal ideation (SI) and/or suicide attempt (SA) and 24 (5 females) with no history of SI and/or SA. Suicidal behavior (SB) was defined as the presence of SI and/or SA. Results We observed no significant differences in GABA/ Creatine+phosphocreatine (Cr+PCr) between veterans with SB (SB+) and without SB (SB-). However, the female SB+ group showed significantly reduced GABA/Cr+PCr vs. the female SB- group. We observed a trend-level significant negative correlation between GABA/Cr+PCr and the defensive avoidance (DA) subscale on the Trauma Symptom Inventory (TSI) in the SB+ group. In contrast, the SB- group exhibited a positive relationship between the two variables. Furthermore, we found significant negative correlations between GABA/Cr+PCr and Hamilton Rating Scale for Depression (HAM-D) scores as well as between GABA/Cr+PCr and several subscales of the TSI in female veterans. Conclusions This study suggests that reduced GABA/Cr+ PCr ratio in the ACC, which may be related to altered inhibitory capacity, may underlie suicide risk in female veterans. Further, the negative association between GABA/Cr+PCr and stress symptomatology and depression scores suggests that MRS studies may shed light on intermediate phenotypes of SB.
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Affiliation(s)
- Andrew Prescot
- Department of Radiology, University of Utah School of
Medicine, Salt Lake City, UT, USA
| | - Chandni Sheth
- Department of Psychiatry, University of Utah School of
Medicine, Salt Lake City, UT, USA
- Diagnostic Neuroimaging, University of Utah, Salt Lake City, UT, USA
| | - Margaret Legarreta
- Diagnostic Neuroimaging, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Department of Veterans
Affairs Medical Center, VA VISN 19 Mental Illness Research, Education and Clinical
Center, Salt Lake City, UT, USA
| | - Perry F. Renshaw
- Department of Psychiatry, University of Utah School of
Medicine, Salt Lake City, UT, USA
- Diagnostic Neuroimaging, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Department of Veterans
Affairs Medical Center, VA VISN 19 Mental Illness Research, Education and Clinical
Center, Salt Lake City, UT, USA
| | - Erin McGlade
- Department of Psychiatry, University of Utah School of
Medicine, Salt Lake City, UT, USA
- Diagnostic Neuroimaging, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Department of Veterans
Affairs Medical Center, VA VISN 19 Mental Illness Research, Education and Clinical
Center, Salt Lake City, UT, USA
| | - Deborah Yurgelun-Todd
- Department of Psychiatry, University of Utah School of
Medicine, Salt Lake City, UT, USA
- Diagnostic Neuroimaging, University of Utah, Salt Lake City, UT, USA
- George E. Wahlen Department of Veterans
Affairs Medical Center, VA VISN 19 Mental Illness Research, Education and Clinical
Center, Salt Lake City, UT, USA
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3
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Du X, Leang L, Mustafa T, Renoir T, Pang TY, Hannan AJ. Environmental enrichment rescues female-specific hyperactivity of the hypothalamic-pituitary-adrenal axis in a model of Huntington's disease. Transl Psychiatry 2012; 2:e133. [PMID: 22760557 PMCID: PMC3410631 DOI: 10.1038/tp.2012.58] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Huntington's disease (HD) has long been regarded as a disease of the central nervous system, partly due to typical disease symptoms that include loss of motor control, cognitive deficits and neuropsychiatric disturbances. However, the huntingtin gene is ubiquitously expressed throughout the body. We had previously reported a female-specific depression-related behavioural phenotype in the R6/1 transgenic mouse model of HD. One hypothesis suggests that pathology of the hypothalamic-pituitary-adrenal (HPA) axis, the key physiological stress-response system that links central and peripheral organs, is a cause of depression. There is evidence of HPA axis pathology in HD, but whether it contributes to the female R6/1 behavioural phenotype is unclear. We have examined HPA axis response of R6/1 mice following acute stress and found evidence of a female-specific dysregulation of the HPA axis in R6/1 mice, which we further isolated to a hyper-response of adrenal cortical cells to stimulation by adrenocorticotrophin hormone. Interestingly, the adrenal pathophysiology was not detected in mice that had been housed in environmentally enriching conditions, an effect of enrichment that was also reproduced in vitro. This constitutes the first evidence that environmental enrichment can in fact exert a lasting influence on peripheral organ function. Cognitive stimulation may therefore not only have benefits for mental function, but also for overall physiological wellbeing.
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Affiliation(s)
- X Du
- Neural Plasticity Laboratory, Behavioural Neuroscience Division, Florey Neuroscience Institutes, University of Melbourne, Parkville, VIC, Australia,Department of Anatomy and Cell Biology, University of Melbourne, Parkville, VIC, Australia
| | - L Leang
- Neural Plasticity Laboratory, Behavioural Neuroscience Division, Florey Neuroscience Institutes, University of Melbourne, Parkville, VIC, Australia
| | - T Mustafa
- National Institute of Mental Health, Section on Molecular Neuroscience, Bethesda, MD, USA
| | - T Renoir
- Neural Plasticity Laboratory, Behavioural Neuroscience Division, Florey Neuroscience Institutes, University of Melbourne, Parkville, VIC, Australia
| | - T Y Pang
- Neural Plasticity Laboratory, Behavioural Neuroscience Division, Florey Neuroscience Institutes, University of Melbourne, Parkville, VIC, Australia,Melbourne Brain Centre, At Genetics Lane, Royal Parade, The University of Melbourne, VIC 2010, Australia. E-mail:
| | - A J Hannan
- Neural Plasticity Laboratory, Behavioural Neuroscience Division, Florey Neuroscience Institutes, University of Melbourne, Parkville, VIC, Australia,Department of Anatomy and Cell Biology, University of Melbourne, Parkville, VIC, Australia
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4
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Trainor BC, Takahashi EY, Silva AL, Crean KK, Hostetler C. Sex differences in hormonal responses to social conflict in the monogamous California mouse. Horm Behav 2010; 58:506-12. [PMID: 20430027 PMCID: PMC2917544 DOI: 10.1016/j.yhbeh.2010.04.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 04/15/2010] [Accepted: 04/15/2010] [Indexed: 11/16/2022]
Abstract
Monogamous species are usually considered to be less likely to exhibit sex differences in behavior or brain structure. Most previous studies examining sex differences in stress hormone responses have used relatively sexually dimorphic species such as rats. We examined the stress hormone responses of monogamous California mice (Peromyscus californicus) to resident-intruder tests. We also tested males and females under different photoperiods, because photoperiod has been shown to affect both aggression and stress hormone responses. Females, but not males showed a significant increase in corticosterone levels immediately following a resident-intruder test. Males but not females showed elevated corticosterone levels under short days. Females tested in aggression tests also showed a significant increase in plasma oxytocin levels, but only when housed in long days. This was consistent with our observation that females but not males had more oxytocin positive cells in the paraventricular nucleus (PVN) when housed under long days. Our data show that sex differences in glucocorticoid responses identified in other rodents are present in a monogamous species.
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Affiliation(s)
- Brian C Trainor
- Department of Psychology, University of California, Davis, CA 95616, USA.
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5
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Abstract
GABA(A) receptors are sensitive to subtle changes in the environment in both early-life and adulthood. These neurochemical responses to stress in adulthood are sex-dependent. Acute stress induces rapid changes in GABA(A) receptors in experimental animals, with the direction of the changes varying according to the sex of the animals and the stress-paradigm studied. These rapid alterations are of particular interest as they provide an example of fast neurotransmitter system plasticity that may be mediated by stress-induced increases in neurosteroids, perhaps via effects on phosphorylation and/or receptor trafficking. Interestingly, some studies have also provided evidence for long-lasting changes in GABA(A) receptors as a result of exposure to stressors in early-life. The short- and long-term stress sensitivity of the GABAergic system implicates GABA(A) receptors in the non-genetic etiology of psychiatric illnesses such as depression and schizophrenia in which stress may be an important factor.
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Affiliation(s)
- Kelly J Skilbeck
- Department of Pharmacology, University of Sydney, Sydney, New South Wales, Australia
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6
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Sex-differences and stress: Effects on regional high and low affinity [3H]GABA binding. Neurochem Int 2008; 52:1212-9. [DOI: 10.1016/j.neuint.2008.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 12/17/2007] [Accepted: 01/02/2008] [Indexed: 11/19/2022]
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7
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Khurana RC, Devaud LL. Sex differences in neurotransmission parameters in response to repeated mild restraint stress exposures in intact male, female and ovariectomised female rats. J Neuroendocrinol 2007; 19:511-20. [PMID: 17532795 DOI: 10.1111/j.1365-2826.2007.01557.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study determined whether a repeated mild restraint stress exposure would differentially alter neuronal activity in male and female rats to gain insights into neurobiological substrates involved in sex differences in stress-induced behavioural responses. In our first set of experiments, we used Western blot analysis to determine whether alterations in several synaptic proteins were elicited by the repeated stress treatment. We found bidirectional changes in synaptophysin levels in female cerebral cortex and hippocampus that diverged between intact and ovariectomised females. There were persistent elevations in spinophilin levels in the male, but not female, hippocampus following the repeated mild restraint stress exposure. By contrast, levels of the NMDA receptor scaffolding protein, PSD-95, were altered only in intact female cerebral cortex and ovariectomised female hippocampus. We next used immunohistochemical evaluation of Fos expression as a marker for neuronal activation. We found significant increases in Fos immunoreactivity in all sex conditions across multiple brain regions in response to the repeated mild stress. Fos protein induction was greatest in the frontal cortex, piriform cortex and amygdala, with the degree of induction varying by sex condition. Fos induction was dramatically higher in amygdala and piriform cortex only in intact females following repeated stress compared to a single restraint stress exposure, suggestive of sensitisation rather than habituation. By contrast, the frontal cortex of intact and ovariectomised females showed habituation to the repeated stressor. Males displayed modest sensitisation in both the frontal cortex and dentate gyrus with no changes in other brain areas. Taken together, these findings show that exposure to a mild repeated stress results in sex differences in synaptic adaptations and patterns of brain activation that likely contribute to observed sex differences in stress-induced behaviours. This approach provides valuable insights into interactions between the hormonal milieu and responses to a repeated mild stress, and further supports the importance of considering hormonal status in treatment of stress-related disorders.
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Affiliation(s)
- R C Khurana
- Department of Pharmaceutical Sciences, College of Pharmacy and Biomedical Research Institute, Idaho State University, Pocatello, ID 83209-8334, USA
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8
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Devaud LL, Risinger FO, Selvage D. Impact of the Hormonal Milieu on the Neurobiology of Alcohol Dependence and Withdrawal. The Journal of General Psychology 2006; 133:337-56. [PMID: 17128955 DOI: 10.3200/genp.133.4.337-356] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Alcoholism, or alcohol dependence, is a complex disorder with withdrawal symptoms that are often problematic for those trying to recover from their dependence. As researchers attempt to elucidate the neurobiological underpinnings of alcohol dependence and withdrawal, it is becoming clear that numerous factors, including the hormonal environment, impact the manifestations of this disorder. Of particular interest is the observation that women have fewer and less severe withdrawal symptoms than do men even though they tend to suffer greater physiological harm from excessive alcohol consumption. In this article, the authors present an overview of their understanding of how gonadal and stress hormones interact with alcohol, which results in differential neurobiological responses between males and females. Thus far, data generated from representative animal models have shown significant differences between the sexes in behavioral responses and neuroadaptations to chronic alcohol consumption and withdrawal. Accumulating evidence suggests that treatment of alcoholism, including withdrawal, should be tailored to the patient's gender and hormonal status.
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Affiliation(s)
- Leslie L Devaud
- Department of Pharmaceutical Sciences, Idaho State University, Pocatello, ID 83209, USA.
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9
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DODD PR, LEWOHL JM. Cell Death Mediated by Amino Acid Transmitter Receptors in Human Alcoholic Brain Damage: Conflicts in the Evidencea. Ann N Y Acad Sci 2006; 844:50-58. [DOI: 10.1111/j.1749-6632.1998.tb08221.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Chadda R, Devaud LL. Differential effects of mild repeated restraint stress on behaviors and GABA(A) receptors in male and female rats. Pharmacol Biochem Behav 2005; 81:854-63. [PMID: 16039700 DOI: 10.1016/j.pbb.2005.06.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Revised: 05/06/2005] [Accepted: 06/03/2005] [Indexed: 11/20/2022]
Abstract
We previously reported that the very mild stress of individual housing influenced seizure risk and gamma-amino butyric acid (GABA(A)) receptor activity differentially between male and female rats. The aim of the present set of studies was to assess sex differences in behavioral responses to a more pronounced type of stressor, repeated restraint stress. We also wanted to determine the role of GABA(A) receptors in effects of this stressor. Our data suggest that repeated restraint stress afforded short-term protection against seizure induction in both male and female rats. Moreover, this protection was more persistent in female than male rats. This stress paradigm also elicited a reduction in general activity in male rats, whereas female rats displayed prolonged increased activity following the repeated restraint stress exposure. However, there were limited effects on anxiety-like behaviors, as determined by time spent in the open arms on the elevated plus maze. Sex differences in stress-induced increases in plasma corticosterone levels were observed, which generally correlated with sex differences in behavioral measures. There were no significant effects of the repeated restraint stress exposure on benzodiazepine/GABA(A) receptor density or affinity nor on receptor function. Taken together, these findings provide additional evidence to support the important influences of sex in responding to stress and highlight the need to consider this context when addressing the role of stress in health issues for women and men.
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Affiliation(s)
- Ritu Chadda
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, Pocatello, ID 83209-8334, United States
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11
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Briones-Aranda A, Rocha L, Picazo O. Alterations in GABAergic function following forced swimming stress. Pharmacol Biochem Behav 2005; 80:463-70. [PMID: 15740789 DOI: 10.1016/j.pbb.2005.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Revised: 01/06/2005] [Accepted: 01/07/2005] [Indexed: 12/01/2022]
Abstract
Forced swimming induces alterations in the GABA brain concentration and could change the sensitivity of the GABA/benzodiazepine receptor-chloride ionophore complex to benzodiazepines. This change in sensitivity could be explained by the allopregnanolone release that takes place during stress. The current study was carried out to determine whether forced swimming is able to modify the anti-anxiety effect of diazepam and to explore the possible relation of this change to allopregnanolone, the GABA concentration or/and the GABA/benzodiazepine receptor density. Unstressed and stressed mice, injected with the vehicle or diazepam, were evaluated in the exploratory behavior test. Diazepam induced clear anxiolytic actions at all doses in unstressed animals, but such an effect was not observed in stressed animals. The injection of allopregnanolone 24 h before the anxiety test blocked the effect of this benzodiazepine. Forced swimming decreased GABA concentrations in the hippocampus and the thalamus-hypothalamus region, besides decreasing the [(3)H]flunitrazepam labeling in both the hypothalamus and amygdala. These results show that forced swimming abolishes the anti-anxiety effect of diazepam.
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Affiliation(s)
- Alfredo Briones-Aranda
- Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Diaz Mirón, Col. Sto. Tomás, 11340 México City, México
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12
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Chadda R, Devaud LL. Sex differences in effects of mild chronic stress on seizure risk and GABAA receptors in rats. Pharmacol Biochem Behav 2005; 78:495-504. [PMID: 15251258 DOI: 10.1016/j.pbb.2004.03.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2004] [Revised: 03/05/2004] [Accepted: 03/09/2004] [Indexed: 01/08/2023]
Abstract
Social stress is a common occurrence in our society that can negatively impact health. Therefore, we wanted to study the effects of a mild stressor designed to model social stress on seizure susceptibility and GABAA receptors in male and female rats. The mild chronic stress of individual housing consistently decreased bicuculline (but not pentylenetetrazol, PTZ) seizure thresholds by 10-15% in both sexes. Housing conditions did not alter the anticonvulsant activity of diazepam or ethanol, although the anticonvulsant effect of ethanol was significantly greater against PTZ-induced seizures. Experiments testing the addition of an acute restraint stress unmasked sex differences in seizure induction. The acute stress also selectively decreased the potency of GABA to modulate GABAA receptor-mediated chloride uptake in group-housed females. There were additional sex differences by housing condition for GABAA receptor-gated chloride uptake but no differences in [3H]flunitrazepam binding. We also found significant effects of sex and housing on ethanol-induced increases in corticosterone (CORT) levels. In summary, there were complex and sex-selective effects of mild chronic stress on seizure induction and GABAA receptors. Gaining a better understanding of mechanisms underlying interactions between sex and stress has important implications for addressing health concerns about stress in men and women.
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Affiliation(s)
- Ritu Chadda
- Department of Pharmaceutical Sciences, College of Pharmacy, Idaho State University, CB 8334, Pocatello, ID 83209-8334, USA
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13
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Sternberg WF, Chesler EJ, Wilson SG, Mogil JS. Acute progesterone can recruit sex-specific neurochemical mechanisms mediating swim stress-induced and kappa-opioid analgesia in mice. Horm Behav 2004; 46:467-73. [PMID: 15465533 DOI: 10.1016/j.yhbeh.2004.05.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Revised: 05/18/2004] [Accepted: 05/19/2004] [Indexed: 10/26/2022]
Abstract
There is a qualitative sex difference in the neurochemical mediation of stress-induced and kappa-opioid analgesia; these phenomena are dependent on N-methyl-d-aspartic acid (NMDA) receptors in males but not females. Progesterone modulation of this sex difference was examined in mice. Analgesia against thermal nociception was produced by forced cold water swim or by systemic administration of the kappa-opioid agonist, U50,488. As seen previously, the NMDA receptor antagonist MK-801 blocked both forms of analgesia in male but not female mice. Also as in previous studies, this sex difference was found to be dependent on ovarian hormones such that ovariectomy induced female mice to "switch" to the male-like, NMDAergic system. We now demonstrate that a single injection of progesterone (50 microg), systemically administered 30 min before analgesia assessment, is sufficient to restore female-specific mediation of analgesia (i.e., insensitivity to MK-801 blockade) in ovariectomized female mice. The rapidity of this neurochemical "switching" action of progesterone suggests mediation via cell surface receptors or the action of neuroactive steroid metabolites of progesterone.
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Affiliation(s)
- Wendy F Sternberg
- Department of Psychology, Haverford College, Haverford, PA 19041, USA.
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14
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Gulinello M, Smith SS. Anxiogenic effects of neurosteroid exposure: sex differences and altered GABAA receptor pharmacology in adult rats. J Pharmacol Exp Ther 2003; 305:541-8. [PMID: 12606703 DOI: 10.1124/jpet.102.045120] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute exposure to progesterone or its neurosteroid derivative allopregnanolone (3alpha,5alpha-THP) is anxiolytic, consistent with the GABA modulatory effects of 3alpha,5alpha-THP at the GABA(A) receptor. However, continuous exposure to progesterone increases anxiety in association with increased expression of the benzodiazepine-insensitive GABA(A) receptor alpha4 subunit. Furthermore, negative mood symptoms and altered GABA(A) receptor pharmacology in patients with premenstrual dysphoric disorder occur in the early luteal phase in association with peak circulating levels of progesterone and 3alpha,5alpha-THP. Because sex differences have been reported in steroid-regulated anxiety responses, the present study investigated the role of sex and development in the regulation of anxiety after short-term exposure to 3alpha,5alpha-THP. To this end, we compared the effects of hormone administration in adult male, adult female, and juvenile female rats. Increased anxiety in the elevated plus maze was evident in all groups after 48-h exposure to either 3alpha,5alpha-THP or progesterone. At this time point, alterations in the anxiolytic profile of benzodiazepine agonists and antagonists were also observed in both adult males and females in the elevated plus maze. However, sex differences in the acoustic startle response were observed after short-term hormone treatment such that only female rats displayed an increased response indicative of higher anxiety levels. These results suggest that although neurosteroid exposure may influence both the pharmacological properties of the GABA(A) receptor and the manifestation of anxiety in both sexes, the effects of neurosteroids may be modulated in a sex- and task-specific manner.
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Affiliation(s)
- M Gulinello
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, Brooklyn, New York, USA.
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15
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Stone DJ, Walsh JP, Sebro R, Stevens R, Pantazopolous H, Benes FM. Effects of pre- and postnatal corticosterone exposure on the rat hippocampal GABA system. Hippocampus 2002; 11:492-507. [PMID: 11732703 DOI: 10.1002/hipo.1066] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Several lines of evidence have implicated prenatal stress and the hippocampal GABA system in the pathophysiology of schizophrenia, and prenatal stress is believed to increase the risk for schizophrenia through alterations of this neurotransmitter. To explore this hypothesis, we treated male rats pre- and/or postnatally (P48 and P60) with either corticosterone (CORT) or vehicle to establish three study groups: VVV, receiving vehicle at all three time points; VCC, receiving vehicle prenatally and CORT at both postnatal timepoints; and CCC, receiving CORT at all three timepoints. Animals were sacrificed at either 24 h or 5 days after final injection and examined for mRNA levels of GAD65, GAD67, and the GABA(A) receptor subunits alpha2 and gamma2. At 24 h, GAD65 mRNA was decreased in CA1, CA2, CA4, and dentate gyrus (DG) of VCC rats; this effect was either decreased or reversed in CCC-treated animals. No effect was detected in GAD67 mRNA at 24 h. At 5 days, CORT treatment increased GAD67 mRNA levels in CA1, CA3, and DG. Prenatal treatment with CORT was associated with increased responsiveness only in CA3 and DG. For the GABAA receptor, alpha2 subunit mRNA did not show any change in response to CORT treatment, while that for the gamma2 subunit was decreased in CA2 of both VCC- and CCC-treated animals. Consistent with gamma2 subunit mRNA decreases, benzodiazepine (BZ) receptor binding activity was decreased in CA2 with CORT treatment. Prenatal CORT exposure neither increased nor decreased this effect. These results demonstrate that CORT administration is associated with a complex regulation of mRNA expression for pre- and postnatal aspects of the hippocampal GABA system. Under these conditions, prenatal exposure to CORT may sensitize some of these effects, but does not fundamentally alter the nature of this response.
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Affiliation(s)
- D J Stone
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts, USA
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Tayyabkhan TR, Mammola BN, Drugan RC. A comparison of female and male rats' ETOH-induced ataxia and exploration following restraint or swim stress. Pharmacol Biochem Behav 2002; 72:335-42. [PMID: 11900804 DOI: 10.1016/s0091-3057(01)00765-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Animal models of stress reactivity are often employed in developing treatments for humans. Many studies use shock stress, and most use male rats. These experiments compare female and male rats exposed to either restraint stress (RS) or ambient-temperature swim stress (SS), using two durations of each stressor and naive controls. The ataxic effects of a 0.6 g/kg i.p. dose of ethanol (ETOH) were measured. Females exhibited less ataxia than males following ETOH administration. There were no significant effects of stress on ETOH-induced ataxia. Exploration was also measured in an open-field test (OFT) both pre- and poststress. In the prestress OFT, females were more active than males. For the no-stress groups and the shorter-duration stress groups, exploration decreased between the first and second OFTs. However, the groups exposed to the longer-duration stress did not show this expected decrease in exploration. A key finding of this research is that while sex differences may be present at baseline, the sexes may react similarly to stress. These data extend knowledge on sex differences in stress, alcohol reactivity and exploratory behavior.
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Affiliation(s)
- Tara R Tayyabkhan
- Department of Psychology, University of New Hampshire, Durham, NH 03824, USA.
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17
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Pericić D, Jazvinsćak M, Svob D, Mirković K. Swim stress alters the behavioural response of mice to GABA-related and some GABA-unrelated convulsants. Epilepsy Res 2001; 43:145-52. [PMID: 11164703 DOI: 10.1016/s0920-1211(00)00194-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To elucidate the relationship between stress and seizures, the effect of a single swim stress on the convulsive signs and death produced by several GABA-related and GABA-unrelated convulsants, and the effect of repeated swim stress on picrotoxin-induced convulsions was studied. Mice were subjected to swim stress (10 min swimming at 18-19 degrees C), and the i.v. infusion of convulsants started 15 min thereafter. The latency to the onset of several convulsant signs and death was measured, and the doses of convulsants producing convulsions and death were calculated. Additional experiments included mice swimming at room temperature, and those which were stressed repeatedly (twice a day for four consecutive days, plus one stressful procedure on the fifth day). Swim stress increased the dose needed to produce convulsant signs and death after bicuculline, picrotoxin, pentylenetetrazole, strychnine and 4-aminopyridine, while kainic acid-induced convulsions were not affected. Using picrotoxin infusion, the effect of swimming in room temperature water was less than the effect of swimming in 18-19 degrees C water. In addition, the effect of repeated stress was less than the effect of acute stress on picrotoxin-induced convulsions. The results demonstrate that acute swim stress lowers the convulsive potency of GABA-related and some GABA-unrelated convulsants. Repeatedly stressed animals develop tolerance to anticonvulsive effect of swim stress.
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Affiliation(s)
- D Pericić
- Laboratory for Molecular Neuropharmacology, Division of Molecular Medicine, Ruder Boskovic Institute, PO Box 180, 10002, Zagreb, Croatia.
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18
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Abstract
To explore the possible involvement of glucocorticoids in the previously observed anticonvulsive effect of swim stress, mice were, prior to administration of convulsants, subjected to treatments that diminish or enhance plasma corticosterone levels. Aminoglutethimide, the inhibitor of steroid synthesis, failed to modify convulsant doses of picrotoxin, but enhanced threshold doses of pentylenetetrazole producing myoclonus and death, both in unstressed and stressed animals. The same drug prevented the effect of stress on pentylenetetrazole-induced running bouncing clonus (RB clonus) and abolished the appearance of tonic hindlimb extension (THE). Doses of kainic acid producing convulsions and death were not affected by stress, but they were enhanced by aminoglutethimide. Corticosterone administration could not imitate the effect of swim stress. Finasteride, a 5 alpha-reductase inhibitor, did not interfere with the effect of stress on picrotoxin-induced convulsions. Swim stress failed to modify the binding of the convulsant t[3H]-butylbicycloorthobenzoate [3H]TBOB, to washed mouse forebrain membranes. The results confirmed an anticonvulsant effect of swim stress against convulsions produced by GABA-related convulsants, but they do not support the hypothesis suggesting the involvement of glucocorticoids or neurosteroids in this effect.
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Affiliation(s)
- D Pericić
- Laboratory for Molecular Neuropharmacology, Ruder Bosković Institute,Bijenićka c. 54, P.O.B. 1016, 10000 Zagreb, Croatia
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19
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Abstract
Here we tested whether exposure to either tailshock or swim stress alters ovarian hormone levels, estrogen and progesterone, in females and whether the effects are persistent. Adrenal hormone levels were also measured in males and females. Estradiol levels were elevated in unstressed females during proestrus relative to females in other stages of estrous, and exposure to the stressors enhanced estradiol beyond basal levels. For females stressed during diestrus 2, estradiol levels were elevated immediately after stressor cessation and up to 24 hrs. Exposure to tailshock, but not swim-stress, transiently enhanced progesterone in females stressed during the stage of proestrus and estrus. Glucocorticoid levels were elevated in response to both stressors and were supraelevated in females under both basal and stress conditions relative to males, particularly in blood from females exposed to acute swim stress. These results indicate that exposure to a relatively acute stressful event immediately and persistently enhances serum estradiol and are discussed in the context of reports that exposure to the same stressors immediately and persistently impairs associative learning in the female rat.
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Affiliation(s)
- T J Shors
- Department of Psychology and Center for Neuroscience Rutgers University, Piscataway, NJ 08854-8020, USA.
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20
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Zinder O, Dar DE. Neuroactive steroids: their mechanism of action and their function in the stress response. ACTA PHYSIOLOGICA SCANDINAVICA 1999; 167:181-8. [PMID: 10606819 DOI: 10.1046/j.1365-201x.1999.00579.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Steroids are usually identified as genomic regulators, yet recently a body of evidence has accumulated demonstrating specific plasma membrane effects, as well as coordinative effects, of some steroids on both membrane and intracellular receptors. The resulting rapid (<1 min) modulation of cellular activity has strongly suggested a non-genomic, and possibly modulatory, role for certain steroid compounds, and dramatic effects on membranes of excitable as well as other tissues have been demonstrated. Steroid synthesis and metabolism have been shown to exist in the CNS, and the effects have been seen in both the central and peripheral nervous systems. The major groups of neuroactive steroids, and their metabolites, have been progesterone, deoxycorticosterone, and some androgens, notably dihydroxyepiandrosterone (DHEA). These compounds show increased concentrations both in blood and in the brain following stress and they have also been associated with anxiolytic effects and antiepileptic activity. In the periphery, some of these compounds show remarkable inhibitory effects on the secretion of catecholamines and other neurotransmitters. The mechanism for the majority of the effects of these steroids is via their effect on receptor-mediated binding to ligand-gated ion channels. Activation of the GABAA receptor complex, resulting in the opening of its central chloride channel, is the major target of the neuroactive steroids, resulting in re-polarization of the plasma membrane and inhibition of further neuronal firing. The anxiolytic, anti-convulsant and sedative-hypnotic actions of these neuroactive steroids have resulted in their being used as therapeutic agents for the treatment of anxiety, epilepsy, insomnia, and possibly for the alteration of pain thresholds.
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Affiliation(s)
- O Zinder
- Department of Clinical Biochemistry, Rambam Medical Center, and the Technion, Israel Institute of Technology, Faculty of Medicine, Haifa, Israel
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21
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Galea LA, McEwen BS, Tanapat P, Deak T, Spencer RL, Dhabhar FS. Sex differences in dendritic atrophy of CA3 pyramidal neurons in response to chronic restraint stress. Neuroscience 1997; 81:689-97. [PMID: 9316021 DOI: 10.1016/s0306-4522(97)00233-9] [Citation(s) in RCA: 416] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The present study investigated the effects of 21 days of chronic restraint stress on neural and endocrine parameters in male and female rats. Consistent with previous results, repeated restraint stress induced apical dendritic atrophy (a decrease in the number of apical branch points and dendritic length) of the CA3c pyramidal neurons in male rats. In contrast, female rats did not show significant dendritic atrophy in the apical field in response to repeated restraint stress. Female rats did show a decrease in the number of branch points in the basal dendritic tree compared to male rats in response to repeated restraint stress. Baseline and stress levels of plasma corticosterone were higher in female rats compared to male rats. Females exhibited slightly longer increases in corticosterone levels throughout the 21 days of restraint stress than males, indicating that the male corticosterone response to stress exhibited greater habituation. Plasma corticosteroid-binding globulin levels of female rats were also higher than those of male rats throughout the experiment. There was no change in plasma corticosteroid-binding globulin levels in male rats during the restraint stress, while there was a decrease in plasma corticosteroid-binding globulin levels in female rats during the restraint stress. Plasma estradiol levels in female rats also decreased in response to the chronic stress. In view of the qualitatively different dendritic atrophy found in males and females in appears unlikely that sex differences in the corticosteroid-binding globulin and corticosterone response can account for these morphological differences.
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Affiliation(s)
- L A Galea
- Laboratory of Neuroendocrinology, Rockefeller University, New York, NY, USA
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22
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Akinci MK, Johnston GA. Sex differences in the effects of gonadectomy and acute swim stress on GABAA receptor binding in mouse forebrain membranes. Neurochem Int 1997; 31:1-10. [PMID: 9185158 DOI: 10.1016/s0197-0186(96)00143-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Gonadectomy of male mice resulted in a significant increase in GABAA receptor binding in forebrain membranes at GABA concentrations of 100-1000 nM, whereas gonadectomy of female mice resulted in no significant change in such binding. Acute swim stress (3 min swim at 32 degrees C) in gonadectomised female mice resulted in a significant increase in GABAA receptor binding in forebrain membranes at GABA concentrations of 400-1000 nM and in the plasma levels of corticosterone, whereas this stress produced no significant change in such binding or steroid levels in gonadectomised male mice. The surgical stress of sham gonadectomy produced significant increases in GABAA receptor binding in forebrain membranes at GABA concentrations of 100-1000 nM in both sexes, such that the acute swim stress induced increase in GABAA receptor binding in unoperated females is not observed. Hormone replacement studies in swim stressed gonadectomised females indicate that intraperitoneal injection of oestrogen (beta-oestradiol, 10 micrograms) or progesterone (6 alpha-methyl-17 alpha-hydroxy-progesterone acetate, 1 mg) significantly decreased GABAA receptor binding in forebrain membranes at GABA concentrations of 100-1000 nM compared to swim stressed, gonadectomised females injected with the sesame oil vehicle. The injection of a combination of oestrogen (1 microgram) and progesterone (0.1 mg) produced a greater reduction in GABAA receptor binding than the injection of either steroid hormone alone. These results indicate that, in addition to neurosteroids and corticosteroids, gonadal steroids contribute to the modulation of GABAA receptor binding in the brains of male and female mice.
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Affiliation(s)
- M K Akinci
- Department of Pharmacology, University of Sydney, NSW, Australia
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23
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Pericić D, Bujas M. Sex differences in bicuculline-induced convulsions: interaction with stress and ligands of benzodiazepine binding sites. Brain Res 1997; 752:279-84. [PMID: 9106468 DOI: 10.1016/s0006-8993(96)01478-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The response to i.v. administration of bicuculline and its interaction with the benzodiazepine agonist diazepam and antagonist flumazenil were studied in male and female handling stressed and swim stressed rats. Both handling stressed and swim stressed male rats needed less bicuculline to produce myoclonic twitch and running/bouncing (RB) clonus than females. Besides, a lower dose of bicuculline produced tonic hindlimb extensor convulsion (THE) in male than in female swim stressed rats. Flumazenil failed to affect seizure thresholds for bicuculline either in handling stressed or in swim stressed animals. Sex differences remained present after diazepam pre-treatment as well. While diazepam enhanced doses of bicuculline producing all three convulsive signs similarly in both handling and swim stressed rats (141-162%), swim stress had the lowest anticonvulsive effect for the onset of myoclonic twitch (110% in males and 117% in females) and the highest for THE (148% in males and 188% in females). The anticonvulsive effect of diazepam was not sex-dependent, while the anticonvulsive effect of swim stress was greater in female than in male rats. The results suggest that greater sensitivity of male rats to bicuculline and the anticonvulsive effect of swim stress do not result from the release of endogenous modulators of benzodiazepine binding sites.
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Affiliation(s)
- D Pericić
- Laboratory for Molecular Neuropharmacology, Ruder Bosković Institute, Zagreb, Croatia.
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24
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Bujas M, Pericić D, Jazvinsćak M. Influence of gender and gonadectomy on bicuculline-induced convulsions and on GABAA receptors. Brain Res Bull 1997; 43:411-6. [PMID: 9241444 DOI: 10.1016/s0361-9230(97)00027-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The response to IV administration of GABAA receptor antagonist bicuculline was studied in young (30 days) and in adult gonad-intact or gonadectomized male and female rats. The properties of GABAA receptors, obtained from cortex and cerebellum 30 days following gonadectomy, and the affinity of muscimol and bicuculline for cortical and cerebellar GABA binding sites were also studied. While young rats failed to show sex differences, the threshold doses of bicuculline producing the first myoclonic twitch and running/bouncing clonus (RB clonus) were lower in adult male than female rats. Fifteen days after gonadectomy or sham operation male rats needed less bicuculline to the onset of myoclonic twitch and RB clonus than identically treated females, while orchidectomized rats needed more bicuculline to the onset of tonic hindlimb extension than all other groups examined. All sex differences disappeared 30 days following gonadectomy. At the same time, in males gonadectomy decreased the affinity and enhanced the density of cortical 3H-muscimol binding sites. In female rats, gonadectomy only decreased the affinity of cortical GABAA receptors. Only regional but not sex differences were observed in the affinity of muscimol and bicuculline for GABAA receptors. Sex differences in the threshold doses of bicuculline-producing convulsions do not correlate either with the properties of cortical and cerebellar GABAA receptors or with the affinity of bicuculline for the same binding sites.
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Affiliation(s)
- M Bujas
- Laboratory for Molecular Neuropharmacology, Ruder Bosković Institute, Zagreb, Croatia
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25
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Pericić D, Pivac N. Effects of diazepam on conflict behaviour and on plasma corticosterone levels in male and female rats. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 1996; 353:369-76. [PMID: 8935702 DOI: 10.1007/bf00261432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The anxiolytic properties of diazepam and its effects on plasma corticosterone levels were compared in male and female, water deprived rats exposed to the punished (0.8 mA) drinking procedure. The effects of diazepam on unpunished licking, tested under familiar or unfamiliar conditions, and on the lick latency were also studied and a comparison between the two sexes was made. Both punished and unpunished drinking were less in females than in males. In both sexes, a clear anticonflict effect, i.e. a much greater effect on punished than on unpunished drinking, was obtained with 2 and 4 mg/kg, but not with 1 mg/kg, of diazepam i.p. Plasma corticosterone levels were higher in water deprived females than in males. Following the punished and unpunished drinking procedure, plasma corticosterone levels were found to have decreased more in female than in male rats, especially after administration of 1 mg/kg of diazepam. Diazepam had similar anticonflict effects in rats of both sexes but had a greater suppressive effect on the plasma corticosterone levels in female rats. There was no correlation between the anxiolytic effects of diazepam and its effect on the plasma corticosterone levels. When testing was done under unfamiliar conditions, the latency to licking was greater in female than in male rats and diazepam (1, 2 and 4 mg/kg) increased this latency in both sexes. The results suggest sex differences in the neuroendocrine, but not in the anxiolytic, effects of diazepam.
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Affiliation(s)
- D Pericić
- Laboratory for Molecular Neuropharmacology, Ruder Bosković Institute, Zagreb, Croatia
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26
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Dodd PR, Kril JJ, Thomas GJ, Watson WE, Johnston GA, Harper CG. Receptor binding sites and uptake activities mediating GABA neurotransmission in chronic alcoholics with Wernicke encephalopathy. Brain Res 1996; 710:215-28. [PMID: 8963662 DOI: 10.1016/0006-8993(95)01399-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Superior frontal cortex (SFC) and primary motor cortex tissue was obtained at autopsy from thirteen severe chronic alcoholics with neuropathologically confirmed Wernicke Encephalopathy (WE) and 22 controls. Cases with both WE and cirrhosis showed markedly fewer neurones in SFC than did WE cases without cirrhosis. The extent of the apparent neuronal loss corresponded to an increase in post-synaptic GABAA receptor sites, as assessed by the binding of [3H]muscimol to synaptic membranes. Increased [3H]muscimol binding was not accompanied by an increase in 'central-type' benzodiazepine binding sites: as assessed by [3H]flunitrazepam binding, these sites were apparently unaltered, while as assessed by [3H]diazepam binding, they were decreased. The affinities of the two benzodiazepine ligands varied differently with disease. These discrepancies between [3H]flunitrazepam and [3H]diazepam binding could not be accounted for, either by the presence of a second, diazepam-preferring, 'central-type' benzodiazepine binding site, or by loss of 'peripheral-type' sites. The changes in the post-synaptic GABAA-benzodiazepine receptor sites did not reflect any regional, disease-related deficit of afferent GABAergic terminals, as assessed by synaptosomal high-affinity [3H]GABA uptake. On a number of indices, it appears most likely that the data reflect both a loss of receptor sites, and a change in the population of receptor sub-types.
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Affiliation(s)
- P R Dodd
- John Wilson Memorial Clinical Research Laboratory, Royal Brisbane Hospital Foundation, Bancroft Centre, Qld, Australia.
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27
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Abstract
gamma-Aminobutyric acid (GABA)A receptors for the inhibitory neurotransmitter GABA are likely to be found on most, if not all, neurons in the brain and spinal cord. They appear to be the most complicated of the superfamily of ligand-gated ion channels in terms of the large number of receptor subtypes and also the variety of ligands that interact with specific sites on the receptors. There appear to be at least 11 distinct sites on GABAA receptors for these ligands.
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Affiliation(s)
- G A Johnston
- Adrien Albert Laboratory of Medicinal Chemistry, Department of Pharmacology, University of Sydney, NSW, Australia
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28
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Affiliation(s)
- A L Morrow
- Department of Psychiatry University of North Carolina School of Medicine, Chapel Hill 27599-7178, USA
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29
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Orchinik M, Weiland NG, McEwen BS. Chronic exposure to stress levels of corticosterone alters GABAA receptor subunit mRNA levels in rat hippocampus. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1995; 34:29-37. [PMID: 8750858 DOI: 10.1016/0169-328x(95)00118-c] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Chronic exposure to stress levels of corticosteroids alters many aspects of hippocampal function and may lead to neurodegeneration. Male rats were treated for 10 days with corticosterone (CORT) or vehicle pellets, and mRNA levels for six gamma-aminobutyric acid (GABAA) receptor subunits were measured. Effects of castration on subunit mRNA levels in CORT- and vehicle-treated animals were also examined. In situ hybridization studies demonstrated that mRNA levels for hippocampal GABAA receptor alpha 1, alpha 2, beta 1, beta 2, beta 3, and gamma 2 subunits were differentially altered by CORT treatment. Levels of alpha 1 and alpha 2 mRNA decreased in the dentate gyrus, and beta 1 mRNA levels decreased in CA1 and dentate gyrus of CORT-, compared to vehicle-treated, animals. In contrast, beta 2 subunit levels increased in all hippocampal regions examined, beta 3 levels increased in the dentate gyrus, and gamma 2 levels increased in CA1-CA3. The alpha 1, beta 1, and beta 2 mRNA levels all increased in the cingulate cortex of CORT-treated animals. There was no significant effect of gonadal state on any of the subunits examined, but there was a significant negative correlation between testosterone levels and mRNA levels of alpha 1, alpha 2 and beta 3 in specific regions. These data demonstrate that chronic exposure to stress levels of CORT produces complex changes in the mRNA levels of multiple GABAA receptor subunits, independently of the CORT-induced suppression of circulating testosterone.
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Affiliation(s)
- M Orchinik
- Laboratory of Neuroendocrinology, Rockefeller University, New York, NY 10021, USA
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30
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Devaud LL, Purdy RH, Morrow AL. The neurosteroid, 3 alpha-hydroxy-5 alpha-pregnan-20-one, protects against bicuculline-induced seizures during ethanol withdrawal in rats. Alcohol Clin Exp Res 1995; 19:350-5. [PMID: 7625568 DOI: 10.1111/j.1530-0277.1995.tb01514.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Prolonged alcohol consumption leads to the development of tolerance to and dependence on ethanol, resulting in a decreased response to the sedative/hypnotic effects of ethanol, and by negative symptomatology following abrupt termination of use. One symptom associated with ethanol withdrawal in humans, as well as laboratory animals, is enhanced susceptibility to seizures. This study investigated the effects of the neurosteroid, 3 alpha-hydroxy-5 alpha-pregnan-20-one (3 alpha-5 alpha-THP), on alterations in seizure sensitivity associated with ethanol withdrawal. 3 alpha-5 alpha-THP is a potent anxiolytic and anticonvulsant agent that acts via selective interactions with GABAA receptors. Extensive evidence suggests that some aspects of ethanol dependence and withdrawal are mediated by alterations in GABAA receptor function. Withdrawal from chronic ethanol exposure elicited dramatic increases in seizure susceptibility in male and female rats. Administration of 3 alpha-5 alpha-THP just before seizure threshold determinations blocked the increased seizure susceptibility induced by ethanol withdrawal. Ethanol-withdrawn animals were protected by 3 alpha-5 alpha-THP at a dose that had no effect on control animal seizure thresholds. Moreover, male and female rats displayed differential responses to the seizure-threshold lowering effects of ethanol withdrawal, as well as the protection by 3 alpha-5 alpha-THP pretreatment. These findings suggest that there are gender differences associated both with ethanol withdrawal as well as the protection by 3 alpha-5 alpha-THP in ethanol-dependent rats.
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Affiliation(s)
- L L Devaud
- Center for Alcohol Studies, University of North Carolina School of Medicine, Chapel Hill 27599-7175, USA
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31
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Gundlach AL, Burazin TC, Jenkins TA, Berkovic SF. Spatiotemporal alterations of central alpha 1-adrenergic receptor binding sites following amygdaloid kindling seizures in the rat: autoradiographic studies using [3H]prazosin. Brain Res 1995; 672:214-27. [PMID: 7749743 DOI: 10.1016/0006-8993(94)01338-i] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Noradrenergic neurons are thought to be involved in the process of seizure development and long-term central nervous system plasticity associated with kindling and epilepsy. These processes involve actions of noradrenaline at alpha 1-, alpha 2- and beta 1-adrenergic receptors. In this study, quantitative in vitro autoradiography was used to investigate possible changes in the density of brain alpha 1-adrenergic receptors in a kindling model of epilepsy in the rat. Kindling was produced by daily unilateral stimulation of the amygdala. The alpha 1A+alpha 1B subtypes of adrenergic receptors were labelled with the alpha 1-selective antagonist, [3H]prazosin and alpha 1B receptors, detected in the presence of 10 nM WB4101 to selectively occupy alpha 1A receptors, accounted for 50% of total alpha 1 receptors in cerebral cortex. Autoradiographic studies identified significant and long-lasting, ipsilateral increases in specific [3H]prazosin binding throughout layers I-III of the cortex in sham-operated, unstimulated rats, presumably caused by the surgical implantation of the stimulating electrode within the basolateral amygdaloid nucleus. Binding to alpha 1A + alpha 1B receptors and alpha 1B receptors was increased by an average of 35 and 60%, respectively under these conditions. Stimulation-evoked seizures produced dramatic bilateral increases in specific [3H]prazosin binding to alpha 1A + alpha 1B receptors and particularly to alpha 1B receptors in layers I-III of all cortical areas examined. These changes were rapidly induced and the largest increases (range alpha 1A + alpha 1B 80-340%; alpha 1B 165-380%) occurred at 0.5-2 h after the last stage 5 kindled seizure. At 1 and 3 days after the last seizure, increases were measured for both alpha 1A + alpha 1B and alpha 1B receptors in layers I-III of particular cortical regions, but not overall (e.g. 60-210% increase in perirhinal cortex at both times, with increases also in retrosplenial, hindlimb, occipital, parietal and temporal cortices). Between 2-8 wk post-stimulation specific receptor binding levels were equivalent to those in sham-operated, unstimulated rats. In contrast to the large and widespread increases in outer cortical [3H]prazosin binding, smaller increases were detected in the inner cortex (layer V-VI) at individual times (65-75% increase at 30 min), while no significant changes occurred in several other brain regions examined, including thalamus, which contained a high density of alpha 1A and alpha 1B receptors, or hippocampus which has a low density of both alpha 1 receptor subtypes.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- A L Gundlach
- University of Melbourne Department of Medicine, Austin Hospital, Heidelberg, Vic., Australia
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32
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Lillrank SM, Oja SS, Saransaari P. The effect of phencyclidine on [3H]GABA and [3H]flunitrazepam binding in the brain of naive and handling-habituated rats. ACTA PHYSIOLOGICA SCANDINAVICA 1995; 153:33-41. [PMID: 7625166 DOI: 10.1111/j.1748-1716.1995.tb09831.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of handling and handling combined with phencyclidine (PCP) treatment on GABAergic neurotransmission were studied in Sprague-Dawley rats. The animal material consisted of handling-habituated (HH, for 11 d), acutely handled (naive, N), handling-habituated and PCP-treated (10 mg kg-1 i.p., HH + PCP) and acutely handled (naive) PCP-treated (N + PCP) and unhandled 'control' rats. The binding of [3H]GABA and [3H]flunitrazepam (FLU) was studied with membranes and the release of [3H]GABA with slices prepared from the striatum and frontal cortex. In the striatum the maximal binding capacity (Bmax) and the binding constant (KD) of [3H]GABA were the same in N and HH rats, but in the frontal cortex KD was lower in N rats. KD constants of [3H]FLU were significantly lower in both brain areas in N rats than in HH rats. After PCP treatment both Bmax and KD for [3H]FLU increased in these two brain areas in handling-habituated rats, whereas Bmax of [3H]GABA diminished. Neither handling nor PCP had any effect on [3H]GABA release from striatal and frontal cortical slices. Handling prior to killing thus affects differently the GABAergic parameters studied and modulates the PCP-induced effects.
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Affiliation(s)
- S M Lillrank
- Tampere Brain Reserach Center, Department of Biomedical Sciences, University of Tampere, Finland
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Morrow AL. Regulation of GABAA receptor function and gene expression in the central nervous system. INTERNATIONAL REVIEW OF NEUROBIOLOGY 1995; 38:1-41. [PMID: 8537199 DOI: 10.1016/s0074-7742(08)60523-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- A L Morrow
- Department of Psychiatry, School of Medicine, University of North Carolina at Chapel Hill 27599, USA
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Wilson MA, Biscardi R. Sex differences in GABA/benzodiazepine receptor changes and corticosterone release after acute stress in rats. Exp Brain Res 1994; 101:297-306. [PMID: 7843316 DOI: 10.1007/bf00228750] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Since many hormonal indices of stress responsiveness are sexually dimorphic in rats, we examined sex differences and the effects of gonadectomy on the stress-related changes in GABAA/benzodiazepine receptors in rats. Intact or ovariectomized female rats displayed a markedly greater corticosterone response and a more pronounced increase in benzodiazepine receptors than males (intact or orchidectomized) after acute handling or swim stress. Swim stress increased benzodiazepine receptor density without modifying affinity in cortex, hippocampus, and hypothalamus. Corticosterone treatment induced benzodiazepine receptor levels comparable to those seen after swim stress in all hormone groups. Handling stress also enhanced cortical low-affinity GABAA receptor levels in males and ovariectomized females. Both GABA and benzodiazepine receptor levels were positively correlated with circulating corticosterone levels in female, but not male groups. GABA/benzodiazepine coupling was unaffected by stress or hormonal status. These sexual dimorphisms in hormonal responses to stress may help elucidate the causes and consequences of stress-induced changes in the GABAA/benzodiazepine receptor complex.
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Affiliation(s)
- M A Wilson
- Department of Pharmacology, University of South Carolina, School of Medicine, Columbia 29208
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Akinci MK, Johnston GA. Sex differences in acute swim stress induced changes in the binding of AMPA (alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) and kainate to glutamate receptors in mouse forebrain. Neurochem Int 1994; 25:169-74. [PMID: 7527684 DOI: 10.1016/0197-0186(94)90036-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Sex differences were found in the binding of [3H]AMPA and [3H]kainate to glutamate receptors in synaptosomal membranes prepared from mouse forebrain. The number of low affinity [3H]AMPA binding and the affinity of [3H]kainate binding was higher in membranes prepared from male mice than from females. Acute swim stress (3 min at 32 degrees C) decreased the number of low affinity [3H]AMPA binding sites and the affinity of [3H]kainate binding in membranes prepared from male mouse forebrain, but not in those prepared from female mice forebrain. As kainate is known to interact with low affinity AMPA binding sites, these observed changes may be associated with binding sites common to AMPA and kainate. They may represent a functional down-regulation of AMPA/kainate binding sites. These sex differences in binding to non-NMDA subclasses of glutamate receptors are similar to than those found in the binding of MK-801 to the NMDA subclass of glutamate receptors, in that the effects of acute swim stress were more pronounced in membranes prepared from male than from female mice. The number of low affinity [3H]AMPA binding sites were decreased by acute swim stress in membranes from male mice, whereas the number of low affinity [3H]MK-801 binding sites increased following acute swim stress.
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Affiliation(s)
- M K Akinci
- Department of Pharmacology, University of Sydney, NSW, Australia
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Akinci MK, Johnston GA. Sex differences in acute swim stress-induced changes in the binding of MK-801 to the NMDA subclass of glutamate receptors in mouse forebrain. J Neurochem 1993; 61:2290-3. [PMID: 8245979 DOI: 10.1111/j.1471-4159.1993.tb07472.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Acute swim stress (3 min at 32 degrees C) in mice produces increases in the binding of MK-801 to the NMDA subclass of glutamate receptors to forebrain membranes prepared from male mice. Scatchard analyses indicate that the observed increases in the binding of MK-801 in membranes from male mice are the result of changes in the affinity and density of low-affinity binding sites and in the density of high-affinity binding sites. In female mice, any changes in the binding of MK-801 appear to be much less pronounced and restricted to the low-affinity binding sites. These results are in contrast to the situation with binding to GABA receptors where acute swim stress increases GABA binding in forebrain membranes much more in female than in male mice. This indicates significant sex differences in the responses of receptors for the major excitatory and inhibitory transmitters to acute swim stress. These rapid changes in MK-801 binding may result from changes in endogenous modulators as appears to be the case in the acute swim stress-induced changes in GABA binding. As with GABA binding, the endogenous modulators are likely to include steroids, the sex differences reflecting differences in modulation by gonadal steroids and the stress-induced changes reflecting differences in modulation by adrenal steroids. Estradiol, progesterone, and corticosterone treatments have been reported by other workers to influence the properties of glutamate receptors.
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Affiliation(s)
- M K Akinci
- Department of Pharmacology, University of Sydney, Australia
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