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Zuo ZF, Liao YH, Ding T, Dong YL, Qu J, Wang J, Wei YY, Lu YC, Liu XZ, Li YQ. Astrocytic NDRG2 is involved in glucocorticoid-mediated diabetic mechanical allodynia. Diabetes Res Clin Pract 2015; 108:128-36. [PMID: 25656762 DOI: 10.1016/j.diabres.2015.01.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 11/14/2014] [Accepted: 01/03/2015] [Indexed: 12/29/2022]
Abstract
AIMS The present study aims to test whether astrocytes contribute to glucocorticoid-mediated diabetic mechanical allodynia. METHODS Streptozotocin (STZ)-induced diabetic rats were used in our study. The intrathecal operation was performed 21 days after the onset of diabetes. Diabetic mechanical allodynia was present 28 d after the onset of diabetes, and the mechanical threshold was tested using von Frey filaments. Immunohistochemistry, including immunofluorescent histochemical staining, was performed to observe the morphology of the spinal dorsal horn (SDH). Western blot analysis was employed as a semi-quantitative assay of the expression levels of GFAP and NDRG2 associated with diabetic mechanical allodynia. RESULTS Diabetic rats displayed mechanical allodynia and activated astrocytes in the SDH 28 days after the onset of diabetes. This allodynia was attenuated by intrathecal administration of the astrocyte-specific inhibitor l-α-aminoadipate. In parallel, intrathecal injection of RU486, a glucocorticoid receptor antagonist, inhibited the activation of astrocytes in the SDH, alleviating the diabetes-induced mechanical allodynia. Furthermore, we found that dorsal horn astrocytes express abundant N-myc downstream-regulated gene 2 (NDRG2), which contributes to astrocyte reactivity. NDRG2 was over-expressed in activated astrocytes in diabetic rats with mechanical allodynia. Intrathecal injection of RU486 prevented the over-expression of NDRG2, which reversed the astrocyte reactivity and diabetic tactile allodynia. CONCLUSIONS These results suggest that glucocorticoid-mediated over-expression of NDRG2 may contribute to the activation of dorsal horn astrocytes, which play a crucial role in diabetic mechanical allodynia. Thus, inhibiting glucocorticoid receptors and/or astrocyte reactivity in the SDH may be a therapeutic strategy for treating diabetic tactile allodynia.
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Affiliation(s)
- Zhong-Fu Zuo
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China; Department of Anatomy, Histology and Embryology, Liaoning Medical University, No. 3-40 Songpo Road, Jinzhou, Liaoning 121000, PR China
| | - Yong-Hui Liao
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Tan Ding
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yu-Lin Dong
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Juan Qu
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Jian Wang
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Yan-Yan Wei
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Ya-Cheng Lu
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China
| | - Xue-Zheng Liu
- Department of Anatomy, Histology and Embryology, Liaoning Medical University, No. 3-40 Songpo Road, Jinzhou, Liaoning 121000, PR China.
| | - Yun-Qing Li
- Department of Anatomy, Histology and Embryology & K.K. Leung Brain Research Centre, Preclinical School of Medicine, The Fourth Military Medical University, Xi'an 710032, PR China.
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Zhu B, Jiang RY, Yang C, Liu N. Adenosine monophosphate-activated protein kinase activation mediates the leptin-induced attenuation of cognitive impairment in a streptozotocin-induced rat model. Exp Ther Med 2015; 9:1998-2002. [PMID: 26136928 DOI: 10.3892/etm.2015.2317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 02/16/2015] [Indexed: 12/19/2022] Open
Abstract
Several lines of evidence have shown that the incidence of cognitive impairment in diabetic patients is significantly higher than that in healthy individuals, but the exact pathogenesis has not been fully elucidated. Furthermore, it has been suggested that leptin may have a therapeutic effect in cognitive dysfunction. The aim of the present study was to observe the effect of leptin on cognitive dysfunction in streptozotocin (STZ)-induced diabetic rats, and to explore whether adenosine monophosphate-activated protein kinase (AMPK) activation was involved in any potential therapeutic effect of leptin. Compared with control rats, STZ rats exhibited decreased levels of AMPK and a poor performance in the Morris water maze, while these changes were reversed by leptin. Furthermore, Compound C, an AMPK antagonist, significantly attenuated the leptin-induced cognitive function improvement in the STZ rats. In conclusion, these results suggest that AMPK activation may play a critical role in the leptin-induced attenuation of STZ-induced cognitive impairment.
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Affiliation(s)
- Bin Zhu
- Department of Critical Care Medicine, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu 213003, P.R. China
| | - Ri-Yue Jiang
- Department of Radiotherapy, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu 213003, P.R. China
| | - Chun Yang
- Department of Anesthesiology, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu 213003, P.R. China
| | - Ning Liu
- Department of Critical Care Medicine, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu 213003, P.R. China
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Hubens CJ, Kaptein PS, ter Horst JP, Voskuyl RA, Schenk GJ. Kainate-induced epileptogenesis alters circular hole board learning strategy but not the performance of C57BL/6J mice. Epilepsy Behav 2014; 41:127-35. [PMID: 25461204 DOI: 10.1016/j.yebeh.2014.09.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 09/12/2014] [Indexed: 01/12/2023]
Abstract
Patients with mesial temporal lobe epilepsy (mTLE) frequently show cognitive deficits. However, the relation between mTLE and cognitive impairment is poorly understood. To gain more insight into epilepsy-associated alterations in cognitive performance, we studied the spatial learning of C57BL/6J mice five weeks after kainate-induced status epilepticus (SE). Typically, structural hippocampal rearrangements take place within five weeks after SE. Mice were monitored by exposing them to four tasks with a focus on spatial memory and anxiety: the circular hole board, modified hole board, novel object-placement task, and elevated plus maze. On the circular hole board, animals showed a higher preference for hippocampus-independent strategies after SE. In contrast, no change in strategy was seen on the modified hole board, but animals with SE were able to finish the task more often. Animals did not have an increased preference for a relocated object in the novel object-placement task but showed an increased locomotion after SE. No indications for altered anxiety were found when tested on the elevated plus maze following SE. These data suggest that the circular hole board is a well-suited paradigm to detect subtle SE-induced hippocampal deficits.
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Affiliation(s)
- Chantal J Hubens
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands; Department of Pharmacology, Leiden Academic Center for Drug Research (LACDR), Leiden, The Netherlands.
| | - Pascale S Kaptein
- Department of Pharmacology, Leiden Academic Center for Drug Research (LACDR), Leiden, The Netherlands
| | - Judith P ter Horst
- Department of Medical Pharmacology, Leiden University Medical Center (LUMC) & LACDR, Leiden, The Netherlands
| | - Rob A Voskuyl
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands; Department of Pharmacology, Leiden Academic Center for Drug Research (LACDR), Leiden, The Netherlands
| | - Geert J Schenk
- Department of Medical Pharmacology, Leiden University Medical Center (LUMC) & LACDR, Leiden, The Netherlands
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Bryce CA, Howland JG. Stress facilitates late reversal learning using a touchscreen-based visual discrimination procedure in male Long Evans rats. Behav Brain Res 2014; 278:21-8. [PMID: 25251839 DOI: 10.1016/j.bbr.2014.09.027] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 08/20/2014] [Accepted: 09/15/2014] [Indexed: 12/12/2022]
Abstract
The stress response is essential to the survival of all species as it maintains internal equilibrium and allows organisms to respond to threats in the environment. Most stress research has focused on the detrimental impacts of stress on cognition and behavior. Reversal learning, which requires a change in response strategy based on one dimension of the stimuli, is one type of behavioral flexibility that is facilitated following some brief stress procedures. The current study investigated a potential mechanism underlying this facilitation by blocking glucocorticoid receptors (GRs) during stress. Thirty-seven male Long Evans rats learned to discriminate between two images on a touchscreen, one of which was rewarded. Once a criterion was reached, rats received stress (30 min of restraint stress or no stress) and drug (GR antagonist RU38486 or vehicle) administration prior to each of the first 3 days of reversal learning. We expected that stress would facilitate reversal learning and RU38486 (10 mg/kg) would prevent this facilitation in both early (<50% correct in one session) and late (>50% correct in one session) stages of reversal learning. Results showed that stressed rats performed better than unstressed rats (fewer days for late reversal, fewer correction trials, and fewer errors) in the late but not early stage of reversal learning. RU38486 did not block the facilitation of RL by stress, although it dramatically increased response, but not reward, latencies. These results confirm the facilitation of late reversal by stress in a touchscreen-based operant task in rats and further our understanding of how stress affects higher level cognitive functioning and behavior.
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Affiliation(s)
- Courtney A Bryce
- Department of Psychology, University of Saskatchewan, Room 154 - 9 Campus Dr., Saskatoon, SK, Canada S7N 5A5
| | - John G Howland
- Department of Physiology, University of Saskatchewan, Room GB33, Health Sciences Building, 107 Wiggins Road, Saskatoon, SK, Canada S7N 5E5.
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Meyer M, Gonzalez Deniselle MC, Hunt H, de Kloet ER, De Nicola AF. The selective glucocorticoid receptor modulator CORT108297 restores faulty hippocampal parameters in Wobbler and corticosterone-treated mice. J Steroid Biochem Mol Biol 2014; 143:40-8. [PMID: 24565565 DOI: 10.1016/j.jsbmb.2014.02.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 02/12/2014] [Accepted: 02/14/2014] [Indexed: 12/12/2022]
Abstract
Mutant Wobbler mice are models for human amyotrophic lateral sclerosis (ALS). In addition to spinal cord degeneration, Wobbler mice show high levels of blood corticosterone, hyperactivity of the hypothalamic-pituitary-adrenal axis and abnormalities of the hippocampus. Hypersecretion of glucocorticoids increase hippocampus vulnerability, a process linked to an enriched content of glucocorticoid receptors (GR). Hence, we studied if a selective GR antagonist (CORT108297) with null affinity for other steroid receptors restored faulty hippocampus parameters of Wobbler mice. Three months old genotyped Wobbler mice received s.c. vehicle or CORT108297 during 4 days. We compared the response of doublecortin (DCX)+ neuroblasts in the subgranular layer of the dentate gyrus (DG), NeuN+ cells in the hilus of the DG, glial fibrillary acidic protein (GFAP)+ astrocytes and the phenotype of Iba1+ microglia in CORT108297-treated and vehicle-treated Wobblers. The number of DCX+ cells in Wobblers was lower than in control mice, whereas CORT108297 restored this parameter. After CORT108297 treatment, Wobblers showed diminished astrogliosis, and changed the phenotype of Iba1+ microglia from an activated to a quiescent form. These changes occurred without alterations in the hypercorticosteronemia or the number of NeuN+ cells of the Wobblers. In a separate experiment employing control NFR/NFR mice, treatment with corticosterone for 5 days reduced DCX+ neuroblasts and induced astrocyte hypertrophy, whereas treatment with CORT108297 antagonized these effects. Normalization of neuronal progenitors, astrogliosis and microglial phenotype by CORT108297 indicates the usefulness of this antagonist to normalize hippocampus parameters of Wobbler mice. Thus, CORT108297 opens new therapeutic options for the brain abnormalities of ALS patients and hyperadrenocorticisms.
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Affiliation(s)
- Maria Meyer
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental-CONICET, Obligado 2490, 1428 Buenos Aires, Argentina
| | - Maria Claudia Gonzalez Deniselle
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental-CONICET, Obligado 2490, 1428 Buenos Aires, Argentina; Dept. of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Paraguay 2155, 1425 Buenos Aires, Argentina
| | - Hazel Hunt
- Corcept Therapeutics, 149 Commonwealth Drive, Menlo Park, CA 94025, USA
| | - E Ronald de Kloet
- LACDR/LUMC, Leiden University, Einstein weg 55, 2333 CC Leiden, The Netherlands
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biología y Medicina Experimental-CONICET, Obligado 2490, 1428 Buenos Aires, Argentina; Dept. of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Paraguay 2155, 1425 Buenos Aires, Argentina.
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Abstract
Corticosteroids secreted as end product of the hypothalamic-pituitary-adrenal axis act like a double-edged sword in the brain. The hormones coordinate appraisal processes and decision making during the initial phase of a stressful experience and promote subsequently cognitive performance underlying the management of stress adaptation. This action exerted by the steroids on the initiation and termination of the stress response is mediated by 2 related receptor systems: mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs). The receptor types are unevenly distributed but colocalized in abundance in neurons of the limbic brain to enable these complementary hormone actions. This contribution starts from a historical perspective with the observation that phasic occupancy of GR during ultradian rhythmicity is needed to maintain responsiveness to corticosteroids. Then, during stress, initially MR activation enhances excitability of limbic networks that are engaged in appraisal and emotion regulation. Next, the rising hormone concentration occupies GR, resulting in reallocation of energy to limbic-cortical circuits with a role in behavioral adaptation and memory storage. Upon MR:GR imbalance, dysregulation of the hypothalamic-pituitary-adrenal axis occurs, which can enhance an individual's vulnerability. Imbalance is characteristic for chronic stress experience and depression but also occurs during exposure to synthetic glucocorticoids. Hence, glucocorticoid psychopathology may develop in susceptible individuals because of suppression of ultradian/circadian rhythmicity and depletion of endogenous corticosterone from brain MR. This knowledge generated from testing the balance hypothesis can be translated to a rational glucocorticoid therapy.
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Affiliation(s)
- E Ron de Kloet
- Department of Medical Pharmacology, Leiden Academic Centre for Drug Research, Leiden University and Department of Endocrinology and Metabolism, Leiden University Medical Center, 2300 RA Leiden, The Netherlands
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Abstract
The primary adrenal cortical steroid hormones, aldosterone, and the glucocorticoids cortisol and corticosterone, act through the structurally similar mineralocorticoid (MR) and glucocorticoid receptors (GRs). Aldosterone is crucial for fluid, electrolyte, and hemodynamic homeostasis and tissue repair; the significantly more abundant glucocorticoids are indispensable for energy homeostasis, appropriate responses to stress, and limiting inflammation. Steroid receptors initiate gene transcription for proteins that effect their actions as well as rapid non-genomic effects through classical cell signaling pathways. GR and MR are expressed in many tissues types, often in the same cells, where they interact at molecular and functional levels, at times in synergy, others in opposition. Thus the appropriate balance of MR and GR activation is crucial for homeostasis. MR has the same binding affinity for aldosterone, cortisol, and corticosterone. Glucocorticoids activate MR in most tissues at basal levels and GR at stress levels. Inactivation of cortisol and corticosterone by 11β-HSD2 allows aldosterone to activate MR within aldosterone target cells and limits activation of the GR. Under most conditions, 11β-HSD1 acts as a reductase and activates cortisol/corticosterone, amplifying circulating levels. 11β-HSD1 and MR antagonists mitigate inappropriate activation of MR under conditions of oxidative stress that contributes to the pathophysiology of the cardiometabolic syndrome; however, MR antagonists decrease normal MR/GR functional interactions, a particular concern for neurons mediating cognition, memory, and affect.
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Affiliation(s)
- Elise Gomez-Sanchez
- G.V.(Sonny) Montgomery V.A. Medical Center and Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi
| | - Celso E. Gomez-Sanchez
- G.V.(Sonny) Montgomery V.A. Medical Center and Department of Medicine, University of Mississippi Medical Center, Jackson, Mississippi
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Zheng X, Zhang X, Kang A, Ran C, Wang G, Hao H. Thinking outside the brain for cognitive improvement: Is peripheral immunomodulation on the way? Neuropharmacology 2014; 96:94-104. [PMID: 24978103 DOI: 10.1016/j.neuropharm.2014.06.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 06/16/2014] [Accepted: 06/19/2014] [Indexed: 02/07/2023]
Abstract
Cognitive impairment is a devastating condition commonly observed with normal aging and neurodegenerative disorders such as Alzheimer's Disease (AD). Although major efforts to prevent or slow down cognitive decline are largely focused within the central nervous system (CNS), it has become clear that signals from the systemic milieu are closely associated with the dysfunctional brain. In particular, the bidirectional crosstalk between the CNS and peripheral immune system plays a decisive role in shaping neuronal survival and function via neuroimmune, neuroendocrinal and bioenergetic mechanisms. Importantly, it is emerging that some neuroprotective and cognition-strengthening drugs may work by targeting the brain-periphery interactions, which could be intriguingly achieved without entering the CNS. We describe here how recent advances in dissecting cognitive deficits from a systems-perspective have contributed to a non-neurocentric understanding of its pathogenesis and treatment strategy. We also discuss the therapeutic and diagnostic implications of these exciting progresses and consider some key issues in the clinical translation. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Affiliation(s)
- Xiao Zheng
- Nanjing University of Chinese Medicine Affiliated Hospital, Nanjing 210029, China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Xueli Zhang
- Zhong Da Hospital, Southeast University, Nanjing 210009, China
| | - An Kang
- School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Chongzhao Ran
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital/Harvard Medical School, Boston 02129, United States
| | - Guangji Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Haiping Hao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
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Piazza FV, Segabinazi E, Centenaro LA, do Nascimento PS, Achaval M, Marcuzzo S. Enriched environment induces beneficial effects on memory deficits and microglial activation in the hippocampus of type 1 diabetic rats. Metab Brain Dis 2014; 29:93-104. [PMID: 24318482 DOI: 10.1007/s11011-013-9467-2] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 11/07/2013] [Indexed: 12/26/2022]
Abstract
Type 1 diabetes mellitus (T1DM) has been associated with long-term complications in the central nervous system, causing brain cellular dysfunctions and cognitive deficits. On the other hand, enriched environment (EE) induces experience-dependent plasticity, especially in the hippocampus, improving the performance of animals in learning and memory tasks. Thus, our objective was to investigate the influence of the EE on memory deficits, locomotion, corticosterone levels, synaptophysin (SYP) protein immunoreactivity, cell survival and microglial activation in the dentate gyrus (DG) of T1DM rat hippocampus. Male Wistar rats (21-day-old) were exposed to EE or maintained in standard housing (controls, C) for 3 months. At adulthood, the C and EE animals were randomly divided and diabetes was induced in half of them. All the animals received 4 doses of BrdU, 24 h apart. Hippocampus-dependent spatial memory, general locomotion and serum corticosterone levels were evaluated at the end of the experiment. The animals were transcardially perfused 30 days post-BrdU administration. Our results showed that EE was able to prevent/delay the development of memory deficits caused by diabetes in rats, however it did not revert the motor impairment observed in the diabetic group. SYP immunoreactivity was increased in the enriched healthy group. The EE decreased the serum corticosterone levels in diabetic adult rats and attenuated the injurious microglial activation, though without altering the decrease of the survival cell. Thus, EE was shown to help to ameliorate cognitive comorbidities associated with T1DM, possibly by reducing hyperactivity in the hypothalamic-pituitary-adrenal axis and microglial activation in diabetic animals.
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Affiliation(s)
- Francele Valente Piazza
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Sarmento Leite 500, CEP: 90050-170, Porto Alegre, RS, Brazil
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Beauquis J, Vinuesa A, Pomilio C, Pavía P, Galván V, Saravia F. Neuronal and glial alterations, increased anxiety, and cognitive impairment before hippocampal amyloid deposition in PDAPP mice, model of Alzheimer's disease. Hippocampus 2014; 24:257-69. [PMID: 24132937 DOI: 10.1002/hipo.22219] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/08/2013] [Indexed: 11/05/2022]
Abstract
In the context of Alzheimer's disease (AD), hippocampal alterations have been well described in advanced stages of the pathology, when amyloid deposition, inflammation and glial activation occur, but less attention has been directed to studying early brain and behavioral changes. Using an animal model of AD, the transgenic PDAPP-J20 mouse at 5 months of age, when no amyloid plaques are present and low cerebral levels of amyloid peptides are detectable, we found structural, morphological, and cellular alterations in the hippocampus. Young transgenic mice showed a reduced hippocampal volume with less number of pyramidal and granular neurons, which additionally exhibited cell atrophy. The neurogenic capability in this zone, measured as DCX+ cells, was strongly diminished and associated to alterations in cell maturity. A decrease in presynaptic synaptophysin optical density was detected in mossy fibers reaching CA3 subfield but not in Golgi stained- CA1 dendritic spine density. Employing confocal microscopy and accurate stereological tools we also found a reduction in the number of GFAP+ cells, along with decreased astrocyte complexity, suggesting a potential detriment of neural support. According with untimely neuroglial alterations, young PDAPP mice failed in the novel location recognition test, that depends on hippocampal function. Moreover, multivariate statistical analysis of the behavioral outcome in the open-field test evidenced an elevated anxiety score in Tg mice compared with age-matched control mice. In line with this, the transgenic group showed a higher number of c-Fos+ nuclei in central and basolateral amygdala, a result that supports the early involvement of the emotionality factor in AD pathology. Applying an integrative approach, this work focuses on early structural, morphological and functional changes and provides new and compelling evidence of behavioral alterations that precede manifest AD.
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Affiliation(s)
- Juan Beauquis
- Instituto de Biología y Medicina Experimental CONICET and Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
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Sun Y, Fang M, Davies H, Hu Z. Mifepristone: a potential clinical agent based on its anti-progesterone and anti-glucocorticoid properties. Gynecol Endocrinol 2014; 30:169-73. [PMID: 24205903 DOI: 10.3109/09513590.2013.856410] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Nowadays, unwanted pregnancy is a major globe tragedy for millions of women, associated with significant direct and indirect costs, no matter for individuals or society. The progesterone receptor antagonist steroid, mifepristone has been widely and effectively using throughout the world for medical abortion, but to a lesser extent for emergency contraception. In this review, we hope to explore the role of mifepristone as a contraceptive, particularly for emergency contraception. Studies of mifepristone have also been expanding to the fields of endometriosis and uterine fibroids. Furthermore, this initially considered reproductive medicine has been investigated in some psychotic diseases and various disorders of hypercortisolism, because of its glucocorticoid receptor antagonism. Mifepristone was approved suitable for patients with hyperglycemia secondary to Cushing's syndrome by the United States Food and Drug Administration (FDA) in 2012. The aim of this article is to review published reports on the anti-progesterone and anti-glucocorticoid properties of mifepristone as a clinical agent. There is a new insight into systematically describing and evaluating the potential efficiency of mifepristone administrated in the field of endocrine and neuroendocrine, not only in obstetrics and gynecology.
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MESH Headings
- Abortifacient Agents, Steroidal/adverse effects
- Abortifacient Agents, Steroidal/pharmacology
- Abortifacient Agents, Steroidal/therapeutic use
- Antidepressive Agents/adverse effects
- Antidepressive Agents/pharmacology
- Antidepressive Agents/therapeutic use
- Contraceptives, Oral, Synthetic/adverse effects
- Contraceptives, Oral, Synthetic/pharmacology
- Contraceptives, Oral, Synthetic/therapeutic use
- Contraceptives, Postcoital, Synthetic/adverse effects
- Contraceptives, Postcoital, Synthetic/pharmacology
- Contraceptives, Postcoital, Synthetic/therapeutic use
- Cushing Syndrome/drug therapy
- Cushing Syndrome/physiopathology
- Endometriosis/drug therapy
- Female
- Humans
- Hyperglycemia/etiology
- Hyperglycemia/prevention & control
- Hypoglycemic Agents/adverse effects
- Hypoglycemic Agents/pharmacology
- Hypoglycemic Agents/therapeutic use
- Leiomyoma/drug therapy
- Male
- Mifepristone/adverse effects
- Mifepristone/pharmacology
- Mifepristone/therapeutic use
- Mood Disorders/drug therapy
- Receptors, Glucocorticoid/antagonists & inhibitors
- Receptors, Progesterone/antagonists & inhibitors
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Affiliation(s)
- Yayi Sun
- Institute of Neuroscience, Zhejiang University School of Medicine , Hangzhou , China and
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Kiray M, Sisman AR, Camsari UM, Evren M, Dayi A, Baykara B, Aksu I, Ates M, Uysal N. Effects of carbon dioxide exposure on early brain development in rats. Biotech Histochem 2014; 89:371-83. [DOI: 10.3109/10520295.2013.872298] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Diabetes cognitive impairments and the effect of traditional chinese herbs. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2013; 2013:649396. [PMID: 24386004 PMCID: PMC3872237 DOI: 10.1155/2013/649396] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 11/15/2013] [Accepted: 11/19/2013] [Indexed: 12/27/2022]
Abstract
The problem of cognitive impairment resulting from diabetes is gaining more acceptance and attention. Both type 1 and type 2 diabetes mellitus have been proved to be associated with reduced performance on numerous domains of cognitive function. Although the exact mechanisms of cognitive impairments in diabetes have not been completely understood, hyperglycemia and insulin resistance seem to play significant roles. And other possible risk factors such as hypoglycemia, insulin deficiency, vascular risk factors, hyperactive HPA axis, depression, and altered neurotransmitters will also be examined. In the meanwhile, this review analyzed the role of the active ingredient of Chinese herbal medicine in the treatment of diabetes cognitive impairments.
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Neurochemical Nature of Cognitive and Emotional Disorders under Conditions of Experimental Diabetes Mellitus. NEUROPHYSIOLOGY+ 2013. [DOI: 10.1007/s11062-013-9369-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Blockade of corticosteroid receptors induces anxiolytic-like effects in streptozotocin-induced diabetic mice, and synergizes with diazepam. Behav Pharmacol 2013; 24:320-7. [DOI: 10.1097/fbp.0b013e3283637de2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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66
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de Kloet ER. Functional profile of the binary brain corticosteroid receptor system: mediating, multitasking, coordinating, integrating. Eur J Pharmacol 2013; 719:53-62. [PMID: 23876452 DOI: 10.1016/j.ejphar.2013.04.053] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 03/27/2013] [Accepted: 04/03/2013] [Indexed: 01/18/2023]
Abstract
This contribution is focused on the action of the naturally occurring corticosteroids, cortisol and corticosterone, which are secreted from the adrenals in hourly pulses and after stress with the goal to maintain resilience and health. To achieve this goal the action of the corticosteroids displays an impressive diversity, because it is cell-specific and context-dependent in coordinating the individual's response to changing environments. These diverse actions of corticosterone are mediated by mineralocorticoid- and glucocorticoid-receptors that operate as a binary system in concert with neurotransmitter and neuropeptide signals to activate and inhibit stress reactions, respectively. Classically MR and GR are gene transcription factors, but recently these receptors appear to mediate also rapid non-genomic actions on excitatory neurotransmission suggesting that they integrate functions over time. Hence the balance of receptor-mediated actions is crucial for homeostasis. This balanced function of mineralo- and glucocorticoid-receptors can be altered epigenetically by a history of traumatic (early) life events and the experience of repeated stressors as well as by predisposing genetic variants in signaling pathways of these receptors. One of these variants, mineralocorticoid receptor haplotype 2, is associated with dispositional optimism in appraisal of environmental challenges. Imbalance in receptor-mediated corticosterone actions was found to leave a genomic signature highlighting the role of master switches such as cAMP response element-binding protein and mammalian target of rapamycin to compromise health, and to promote vulnerability to disease. Diabetic encephalopathy is a pathology of imbalanced corticosterone action, which can be corrected in its pre-stage by a brief treatment with the antiglucocorticoid mifepristone.
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Affiliation(s)
- E R de Kloet
- Department of Medical Pharmacology, Leiden Academic Center for Drug Research & Department of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, The Netherlands.
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Shin JH, Seong JK, Yi SS. Sequential alterations of glucocorticoid receptors in the hippocampus of STZ-treated type 1 diabetic rats. J Vet Sci 2013; 15:19-26. [PMID: 23820217 PMCID: PMC3973762 DOI: 10.4142/jvs.2014.15.1.19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/11/2013] [Indexed: 12/28/2022] Open
Abstract
Type 1 diabetes is a common metabolic disorder accompanied by increased blood glucose levels along with glucocorticoid and cognitive deficits. The disease is also thought to be associated with environmental changes in brain and constantly induces oxidative stress in patients. Therefore, glucocorticoid-mediated negative feedback mechanisms involving the glucocorticoid receptor (GR) binding site are very important to understand the development of this disease. Many researchers have used streptozotocin (STZ)-treated diabetic animals to study changes in GR expression in the brain. However, few scientists have evaluated the hyperglycemic period following STZ exposure. In the present study, we found GR expression in the hippocampus varied based on the period after STZ administration for up to 4 weeks. We performed immunohistochemistry and Western blotting to validate the sequential alterations of GR expression in the hippocampus of STZ-treated type 1 diabetic rats. GR protein expression increased significantly until week 3 but decreased at week 4 following STZ administration. GR expression after 70 mg/kg STZ administration was highest at 3 weeks post-treatment and decreased thereafter. Although STZ-induced increase in GR expression in diabetic animals has been described, our data indicate that researchers should consider the sequential GR expression changes during the hyperglycemic period following STZ exposure.
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Affiliation(s)
- Jae Hoon Shin
- Laboratory of Developmental Biology and Genomics, College of Veterinary Medicine, Seoul National University, Seoul 151-742, Korea
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68
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Effects of diabetes on hippocampal neurogenesis: links to cognition and depression. Neurosci Biobehav Rev 2013; 37:1346-62. [PMID: 23680701 DOI: 10.1016/j.neubiorev.2013.03.010] [Citation(s) in RCA: 170] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 03/11/2013] [Accepted: 03/14/2013] [Indexed: 12/29/2022]
Abstract
Diabetes often leads to a number of complications involving brain function, including cognitive decline and depression. In addition, depression is a risk factor for developing diabetes. A loss of hippocampal neuroplasticity, which impairs the ability of the brain to adapt and reorganize key behavioral and emotional functions, provides a framework for understanding this reciprocal relationship. The effects of diabetes on brain and behavioral functions in experimental models of type 1 and type 2 diabetes are reviewed, with a focus on the negative impact of impaired hippocampal neurogenesis, dendritic remodeling and increased apoptosis. Mechanisms shown to regulate neuroplasticity and behavior in diabetes models, including stress hormones, neurotransmitters, neurotrophins, inflammation and aging, are integrated within this framework. Pathological changes in hippocampal function can contribute to the brain symptoms of diabetes-associated complications by failing to regulate the hypothalamic-pituitary-axis, maintain learning and memory and govern emotional expression. Further characterization of alterations in neuroplasticity along with glycemic control will facilitate the development and evaluation of pharmacological interventions that could successfully prevent and/or reverse the detrimental effects of diabetes on brain and behavior.
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Breivik T, Gundersen Y, Gjermo P, Opstad PK. Chronic treatment with the glucocorticoid receptor antagonist RU486 inhibits diabetes-induced enhancement of experimental periodontitis. J Periodontal Res 2013; 49:36-44. [PMID: 23586673 DOI: 10.1111/jre.12076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2013] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVE Chronic hypothalamic-pituitary-adrenal (HPA) axis hyperactivity and excessive glucocorticoid hormone release have been associated with diabetes, altered immune responses and increased susceptibility to periodontitis. In the present study we tested the impact of streptozotocin (STZ)-induced diabetes on ligature-induced periodontitis and the effect of subsequent treatment with the glucocorticoid receptor (GR) antagonist, RU486. MATERIAL AND METHODS A single dose of STZ [45 mg/kg, intraperitoneally (i.p.)] or vehicle was given 10 d before induction of ligature-induced periodontitis and implantation subcutaneously of a drug pellet containing the GR antagonist, RU486, or a placebo pellet. Periodontitis was assessed when the ligatures had been in place for 21 d. Two hours before decapitation all rats received gram-negative bacterial lipopolysaccharide (LPS) (150 μg/kg, i.p.) to induce a robust immune and stress response. RESULTS Compared with control rats, STZ-treated rats developed significantly more periodontal bone loss, and RU486 treatment of STZ -treated rats significantly inhibited this effect. STZ-treated rats also showed significantly higher levels of the HPA axis-derived hormone, corticosterone, as well as of the proinflammatory cytokine, tumor necrosis factor-alpha (TNF-α), but lower levels of the anti-inflammatory cytokines interleukin-10 (IL-10) and transforming growth factor-1beta (TGF-1β) after LPS stimulation. GR blockade had no statistically significant effects on these measurements in diabetic rats, but tended to enhance the levels of TNF-α and TGF-1β, and reduce the levels of IL-10 and blood glucose. CONCLUSION In diabetic subjects, excessive GR activation as a result of chronic high levels of glucocorticoid hormones may alter immune-system responses in a manner that may increase the susceptibility to periodontitis.
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Affiliation(s)
- T Breivik
- Faculty of Dentistry, Department of Periodontology, University of Oslo, Oslo, Norway; Division of Protection, Norwegian Defence Research Establishment, Kjeller, Norway
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70
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Reduction of the cholesterol sensor SCAP in the brains of mice causes impaired synaptic transmission and altered cognitive function. PLoS Biol 2013; 11:e1001532. [PMID: 23585733 PMCID: PMC3621654 DOI: 10.1371/journal.pbio.1001532] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/26/2013] [Indexed: 01/21/2023] Open
Abstract
The sterol sensor SCAP is a key regulator of SREBP-2, the major transcription factor controlling cholesterol synthesis. Recently, we showed that there is a global down-regulation of cholesterol synthetic genes, as well as SREBP-2, in the brains of diabetic mice, leading to a reduction of cholesterol synthesis. We now show that in mouse models of type 1 and type 2 diabetes, this is, in part, the result of a decrease of SCAP. Homozygous disruption of the Scap gene in the brains of mice causes perinatal lethality associated with microcephaly and gliosis. Mice with haploinsufficiency of Scap in the brain show a 60% reduction of SCAP protein and ~30% reduction in brain cholesterol synthesis, similar to what is observed in diabetic mice. This results in impaired synaptic transmission, as measured by decreased paired pulse facilitation and long-term potentiation, and is associated with behavioral and cognitive changes. Thus, reduction of SCAP and the consequent suppression of cholesterol synthesis in the brain may play an important role in the increased rates of cognitive decline and Alzheimer disease observed in diabetic states.
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71
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Tirassa P, Maccarone M, Florenzano F, Cartolano S, De Nicolò S. Vascular and neuronal protection induced by the ocular administration of nerve growth factor in diabetic-induced rat encephalopathy. CNS Neurosci Ther 2013; 19:307-18. [PMID: 23528019 DOI: 10.1111/cns.12085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/18/2013] [Accepted: 02/02/2013] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Based on our previous findings on the efficacy of ocular applied nerve growth factor as eye drops (oNGF) to act in brain and counteract neuronal damage, we hypothesized that oNGF treatment might revert neuronal atrophy occurring in diabetic brain also by controlling neurotrophin system changes. The major NGF brain target areas, such as the septum and the hippocampus, were used as an experimental paradigma to test this hypothesis. METHODS Bilateral oNGF treatment was performed twice a day for 2 weeks in full-blown streptozotocin-treated adult male rats. The forebrain distribution of cholinergic and endothelial cell markers and NGF receptors were studied by confocal microscopy. The septo-hippocampal content of NGF mature and precursor form and NGF receptors expression were also analyzed by Elisa and Western blot. RESULTS oNGF treatment recovers the morphological alterations and the neuronal atrophy in septum and normalized the expression of mature and pro-NGF, as well as NGF receptors in the septum and hippocampus of diabetic rats. In addition, oNGF stimulated brain vascularization and up-regulated the TRKA receptor in vessel endothelium. CONCLUSIONS Our findings confirm that reduced availability of mature NGF and NGF signaling impairment favors vascular and neuronal alterations in diabetic septo-hippocampal areas and corroborate the ability of oNGF to act as a neuroprotective agent in brain.
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Affiliation(s)
- Paola Tirassa
- Institute of Cellular Biology and Neurobiology, National Research Council (CNR), Rome, Italy.
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72
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Baitharu I, Deep SN, Jain V, Prasad D, Ilavazhagan G. Inhibition of glucocorticoid receptors ameliorates hypobaric hypoxia induced memory impairment in rat. Behav Brain Res 2013; 240:76-86. [DOI: 10.1016/j.bbr.2012.11.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2012] [Revised: 11/05/2012] [Accepted: 11/07/2012] [Indexed: 01/03/2023]
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73
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Sasaki-Hamada S, Sacai H, Oka JI. Diabetes onset influences hippocampal synaptic plasticity in streptozotocin-treated rats. Neuroscience 2012; 227:293-304. [DOI: 10.1016/j.neuroscience.2012.09.081] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 09/27/2012] [Accepted: 09/28/2012] [Indexed: 12/01/2022]
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A randomized trial to examine the effect of mifepristone on neuropsychological performance and mood in patients with bipolar depression. Biol Psychiatry 2012; 72:943-9. [PMID: 22770649 DOI: 10.1016/j.biopsych.2012.05.029] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Revised: 04/24/2012] [Accepted: 05/15/2012] [Indexed: 12/26/2022]
Abstract
BACKGROUND Deficits in neuropsychological performance are found in patients with bipolar disorder and represent a potential treatment target for novel therapeutic strategies. We have previously demonstrated a beneficial effect on spatial working memory (SWM) of treatment for 1 week with the progesterone and glucocorticoid receptor antagonist mifepristone, evident 2 weeks after the cessation of treatment. METHODS We examined the longer-term efficacy of 600 mg/day of mifepristone as an adjunctive treatment, for 1 week, in a placebo-controlled, randomized, double-blind trial in 60 patients with bipolar depression, with SWM as the primary outcome measure. A comparator group of healthy control subjects was also recruited. RESULTS At baseline, neuropsychological performance of patients was impaired, but hypothalamic-pituitary-adrenal axis function did not differ from that of control subjects. Mifepristone treatment was associated with a time-limited increase in cortisol awakening response and with a sustained improvement in SWM performance, which was evident 7 weeks after the cessation of treatment. The magnitude of this neuropsychological response was predicted by the magnitude of the cortisol response to mifepristone. The response occurred in the absence of a significant improvement in depressed mood. CONCLUSIONS These data accord with the findings of animal studies and demonstrate that brief treatment with mifepristone is associated with a sustained improvement in SWM, an effect that might be mediated by a persistent enhancement in hippocampal mineralocorticoid receptor function.
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75
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Aksu I, Ates M, Baykara B, Kiray M, Sisman AR, Buyuk E, Baykara B, Cetinkaya C, Gumus H, Uysal N. Anxiety correlates to decreased blood and prefrontal cortex IGF-1 levels in streptozotocin induced diabetes. Neurosci Lett 2012; 531:176-81. [PMID: 23123774 DOI: 10.1016/j.neulet.2012.10.045] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2012] [Revised: 10/12/2012] [Accepted: 10/14/2012] [Indexed: 01/03/2023]
Abstract
It is well known that diabetes mellitus may cause neuropsychiatric disorders such as anxiety disorders. Diabetes may also cause reduced IGF-1 (insulin like growth factor-1) levels in brain and blood. The purpose of the present study was to investigate the relationship between diabetes induced anxiety and IGF-1 levels in diabetic rats. The anxiety levels of rats were assessed 2 weeks after intraperitoneal injection of streptozotocin. Diabetic rats had higher levels of anxiety, as they spent more time in closed branches in elevated-plus-maze-test and less time in the center cells of open-field-arena. Prefrontal cortex (PFC) IGF-1 levels and neuron numbers were decreased and apoptosis was increased in diabetic rats. Blood IGF-1 levels decreased in a time dependent fashion following streptozotocin injection while blood corticosterone levels increased. They had higher malondialdehyde levels and lower superoxide dismutase enzyme activity. Oxidative stress may negatively affect blood and PFC tissue IGF-1 levels. Reduction in IGF-1 may cause PFC damage, which may eventually trigger anxiety in diabetic rats. Therapeutic strategies that increase blood and brain tissue IGF-1 levels may be promising to prevent psychiatric sequelae of diabetes mellitus.
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Affiliation(s)
- Ilkay Aksu
- Dokuz Eylul University, Faculty of Medicine, Department of Physiology, Turkey
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76
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Guizhi-Fuling-Wan, a Traditional Chinese Herbal Medicine, Ameliorates Memory Deficits and Neuronal Apoptosis in the Streptozotocin-Induced Hyperglycemic Rodents via the Decrease of Bax/Bcl2 Ratio and Caspase-3 Expression. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2012; 2012:656150. [PMID: 23304209 PMCID: PMC3523741 DOI: 10.1155/2012/656150] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Revised: 09/24/2012] [Accepted: 10/08/2012] [Indexed: 12/26/2022]
Abstract
Brain neuronal apoptosis and cognitive impairment are associated with hyperglycemia and diabetes mellitus. The present study determined if the Chinese herbal medicine Guizhi-Fuling-Wan (GFW) would reduce memory loss and neuronal apoptosis in streptozotocin- (STZ-) induced hyperglycemic rodents. Two weeks after STZ induction, GFW was orally administered once daily for 7 days. GFW significantly improved spatial memory deficits in STZ-induced hyperglycemic mice. GFW decreased TUNEL-positive cells and caspase-3 positive cells in STZ-induced hyperglycemic rats. It also was found that GFW treatment reduced caspase-3 protein levels and increased levels of the antiapoptotic protein Bcl-2 that were indicative of neuroprotection. The protective therapeutic effects of GFW on neuronal apoptosis and cognition deficits caused by STZ-induced hyperglycemia may be due in part to inhibition of the cellular apoptosis pathway. GFW may have therapeutic effects in patients with diabetes-mellitus-induced neuropathology.
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Participation of antioxidant and cholinergic system in protective effect of naringenin against type-2 diabetes-induced memory dysfunction in rats. Neuroscience 2012; 226:62-72. [PMID: 22999973 DOI: 10.1016/j.neuroscience.2012.09.026] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 08/30/2012] [Accepted: 09/11/2012] [Indexed: 11/21/2022]
Abstract
Naringenin is a flavone flavonoid possessing antidiabetic, antioxidant and memory improving effects. Therefore, we studied the influence of naringenin against type-2 diabetes-induced memory dysfunction in rats. Type-2 diabetes was induced by high-fat diet and high-fat emulsion for two weeks and a low dose of streptozotocin (35 mg/kg). The memory deficit was assessed by using a novel object recognition paradigm. The changes in oxidative markers and cholinesterase (ChE) levels were evaluated in the hippocampal region. After confirmation of diabetes, naringenin (50mg/kg) treatment was given to animals as a preventive and in another set of experiments naringenin (25 and 50mg/kg) or pioglitazone (5mg/kg) or donepezil (3mg/kg) treatments were started after long-standing diabetes (4 weeks after confirmation). Both the treatment schedules show significant protection and improvement in cognitive behavior against diabetes-induced memory dysfunction and biochemical changes. Also, treatment with pioglitazone and donepezil improved memory performance in rats. Naringenin was found to decrease oxidative stress by depleting elevated lipid peroxide and nitric oxide and elevating reduced glutathione levels. Cholinergic function was improved by naringenin through the inhibition of elevated ChE activity. In conclusion, the present study suggests that naringenin acts as an antioxidant and ChE inhibitor against type-2 diabetes-induced memory dysfunction.
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Liao MJ, Lin LF, Zhou X, Zhou XW, Xu X, Cheng X, Gao Q, Luo HM. Daphnetin prevents chronic unpredictable stress-induced cognitive deficits. Fundam Clin Pharmacol 2012; 27:510-6. [PMID: 22715971 DOI: 10.1111/j.1472-8206.2012.01049.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2011] [Revised: 04/06/2012] [Accepted: 05/10/2012] [Indexed: 12/25/2022]
Abstract
Chronic exposure to stress hormones might impair cognitive functions such as learning and memory, which were associated with many mood disorders and neurodegenerative diseases. In this study, we aimed to screen for effective compounds to prevent cognitive deficits induced by chronic stress. Daphnetin was found to protect the cortical neurons against dexamethasone-induced reduction of cell viability in a dose-dependent manner in vitro. We further evaluated its effects on chronic unpredictable stress (CUS) mice in vivo. Two and 8 mg/kg administration of daphnetin could improve the performance of stress mice in Morris water maze tests and forced swimming tests. The results suggested that daphnetin might be a potent compound to treat cognitive deficits induced by CUS.
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Affiliation(s)
- Min-Jing Liao
- Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, 510632, China
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79
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Bhutada P, Mundhada Y, Humane V, Rahigude A, Deshmukh P, Latad S, Jain K. Agmatine, an endogenous ligand of imidazoline receptor protects against memory impairment and biochemical alterations in streptozotocin-induced diabetic rats. Prog Neuropsychopharmacol Biol Psychiatry 2012; 37:96-105. [PMID: 22300747 DOI: 10.1016/j.pnpbp.2012.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 01/19/2012] [Accepted: 01/19/2012] [Indexed: 12/27/2022]
Abstract
Agmatine, a polycationic amine synthesized via decarboxylation of l-arginine by arginine decarboxylase is reported to exhibit anti-hyperglycemic, antioxidant and memory enhancing effects. Therefore, we tested its influence against cognitive dysfunction in streptozotocin-induced diabetic rats using Morris water maze and object recognition paradigm. Lipid peroxidation and glutathione levels as parameters of oxidative stress and choline esterase (ChE) activity as a marker of cholinergic function were assessed in the cerebral cortex and hippocampus. Thirty days after diabetes induction rats showed a severe deficit in learning and memory associated with increased lipid peroxidation, decreased reduced glutathione, and elevated ChE activity. In contrast, chronic treatment with agmatine (5-10mg/kg, i.p. for 30 days) improved cognitive performance, lowered hyperglycemia, oxidative stress, and ChE activity in diabetic rats. Further, memory improving effects of agmatine were independent of adrenal I(2) imidazoline receptors. In a separate set, agmatine treatment for an initial 15 days after diabetes confirmation also significantly reduced memory impairment during training trials after 30 days of diabetes confirmation. Moreover, treatment during training trials (30 days after diabetes) also significantly reduced memory impairment in diabetic rats. In conclusion, the present study demonstrates that treatment with agmatine prevents changes in oxidative stress and ChE activity, and probably consequent memory impairment in diabetic rats.
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Affiliation(s)
- Pravinkumar Bhutada
- Sinhgad College of Pharmacy, Post-Graduate Research Department, Off Sinhgad road, Vadgaon (Bk), Pune 41, Maharashtra, India.
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Pell GS, Lin A, Wellard RM, Werther GA, Cameron FJ, Finch SJ, Papoutsis J, Northam EA. Age-related loss of brain volume and T2 relaxation time in youth with type 1 diabetes. Diabetes Care 2012; 35:513-9. [PMID: 22301124 PMCID: PMC3322703 DOI: 10.2337/dc11-1290] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE 2 Childhood-onset type 1 diabetes is associated with neurocognitive deficits, but there is limited evidence to date regarding associated neuroanatomical brain changes and their relationship to illness variables such as age at disease onset. This report examines age-related changes in volume and T2 relaxation time (a fundamental parameter of magnetic resonance imaging that reflects tissue health) across the whole brain. RESEARCH DESIGN AND METHODS Type 1 diabetes, N = 79 (mean age 20.32 ± 4.24 years), and healthy control participants, N = 50 (mean age 20.53 ± 3.60 years). There were no substantial group differences on socioeconomic status, sex ratio, or intelligence quotient. RESULTS Regression analyses revealed a negative correlation between age and brain changes, with decreasing gray matter volume and T2 relaxation time with age in multiple brain regions in the type 1 diabetes group. In comparison, the age-related decline in the control group was small. Examination of the interaction of group and age confirmed a group difference (type 1 diabetes vs. control) in the relationship between age and brain volume/T2 relaxation time. CONCLUSIONS We demonstrated an interaction between age and group in predicting brain volumes and T2 relaxation time such that there was a decline in these outcomes in type 1 diabetic participants that was much less evident in control subjects. Findings suggest the neurodevelopmental pathways of youth with type 1 diabetes have diverged from those of their healthy peers by late adolescence and early adulthood but the explanation for this phenomenon remains to be clarified.
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Affiliation(s)
- Gaby S Pell
- Brain Research Institute, Austin Repatriation Medical Centre, Heidelberg, Victoria, Australia
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81
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de Senna PN, Ilha J, Baptista PPA, do Nascimento PS, Leite MC, Paim MF, Gonçalves CA, Achaval M, Xavier LL. Effects of physical exercise on spatial memory and astroglial alterations in the hippocampus of diabetic rats. Metab Brain Dis 2011; 26:269-79. [PMID: 21892662 DOI: 10.1007/s11011-011-9262-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 08/24/2011] [Indexed: 01/08/2023]
Abstract
Type 1 diabetes mellitus (T1DM) is associated with neurocognitive dysfunction and astrogliosis. Physical exercise prevents cognitive impairments and induces important brain modifications. The aim of our study was to investigate the effect of treadmill exercise on spatial memory and astrocytic function in the hippocampus of a T1DM model. Fifty-seven Wistar rats were divided into four groups: trained control (TC) (n = 15), non-trained control (NTC) (n = 13), trained diabetic (TD) (n = 14) and non-trained diabetic (NTD) (n = 15). One month after streptozotocin-induced diabetes, exercise groups were submitted to 5 weeks of physical training, and then, all groups were assessed in the novel object-placement recognition task. Locomotor activity was analyzed in the open field apparatus using Any-maze software. The expression of glial fibrillary acidic protein (GFAP) and S100B in hippocampus and cerebrospinal fluid were measured using ELISA assay, and hippocampal GFAP immunoreactivity was evaluated by means of immunohistochemistry and optical densitometry. The results showed that physical exercise prevents and/or reverts spatial memory impairments observed in NTD animals (P < 0.01). Decreased locomotor activity was observed in both the NTD and TD groups when compared with controls (P < 0.05). ELISA and immunohistochemistry analyzes showed there was a reduction in GFAP levels in the hippocampus of NTD animals, which was not found in TD group. ELISA also showed an increase in S100B levels in the cerebrospinal fluid from the NTD group (P < 0.01) and no such increase was found in the TD group. Our findings indicate that physical exercise prevents and/or reverts the cognitive deficits and astroglial alterations induced by T1DM.
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Affiliation(s)
- Priscylla Nunes de Senna
- Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
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Balkaya M, Prinz V, Custodis F, Gertz K, Kronenberg G, Kroeber J, Fink K, Plehm R, Gass P, Laufs U, Endres M. Stress Worsens Endothelial Function and Ischemic Stroke via Glucocorticoids. Stroke 2011; 42:3258-64. [DOI: 10.1161/strokeaha.110.607705] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Mustafa Balkaya
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Vincent Prinz
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Florian Custodis
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Karen Gertz
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Golo Kronenberg
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Jan Kroeber
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Klaus Fink
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Ralph Plehm
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Peter Gass
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Ulrich Laufs
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
| | - Matthias Endres
- From the Klinik für Neurologie (M.B., V.P., K.G., G.K., M.E.) and the Center for Stroke Research Berlin (M.B., V.P., K.G., G.K., J.K., M.E.), Charité Universitätsmedizin Berlin, Berlin, Germany; Klinik für Innere Medizin III (F.C., U.L.), Saarland University Hospital and Faculty of Medicine, Homburg/ Saar, Germany; Klinik für Psychiatrie CBF (G.K.), Charité Universitätsmedizin Berlin, Germany; the Institute of Pharmacology (K.F.), Bonn University, Bonn, Germany; Max-Delbrück-Center for Molecular
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Ho N, Balu DT, Hilario MRF, Blendy JA, Lucki I. Depressive phenotypes evoked by experimental diabetes are reversed by insulin. Physiol Behav 2011; 105:702-8. [PMID: 21945451 DOI: 10.1016/j.physbeh.2011.09.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 09/01/2011] [Accepted: 09/03/2011] [Indexed: 01/16/2023]
Abstract
Clinical studies suggest a bidirectional relationship between diabetes and depression, where diabetes may increase risk for depressive symptoms and depression may increase risk for diabetes. Preclinical models examining the effects of diabetes on brain and behavior can provide insights to the pathophysiology underlying this relationship. The current study comprehensively examined, in C57BL/6 mice, the development of depressive phenotypes evoked by diabetes induced by streptozotocin (STZ) and determined if insulin treatment was able to reverse the diabetes-related changes on brain and affective behavior. Since anxiety is often comorbid with mood disturbances, behavioral tests for both anxiety and depression were administered. Possible physiological correlates of behavioral changes, including hippocampal cell proliferation, brain derived neurotrophic factor, and plasma corticosterone, were also measured. STZ-induced diabetes resulted in increased immobility in the tail suspension test, increased intracranial self-stimulation thresholds, decreased hippocampal cell proliferation, and increased corticosterone levels. Insulin treatment, on the other hand, reduced hyperglycemia, reversed the behavioral effects, and returned hippocampal cell proliferation and corticosterone to levels comparable to the control group. Anxiety-related behaviors were unaffected. This study showed that experimental diabetes in the mouse produced depressive phenotypes that were reversed by insulin therapy. Changes in reward-related behaviors and hippocampal cell proliferation may be useful markers to identify therapeutic interventions for comorbid diabetes and depression.
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Affiliation(s)
- Nancy Ho
- School of Nursing, University of Pennsylvania, 418 Curie Boulevard, Philadelphia, PA 19104, USA
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84
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Abstract
The prevalence of obesity has rapidly escalated and now represents a major public health concern. Although genetic associations with obesity and related metabolic disorders such as diabetes and cardiovascular disease have been identified, together they account for a small proportion of the incidence of disease. Environmental influences such as chronic stress, behavioral and metabolic disturbances, dietary deficiency, and infection have now emerged as contributors to the development of metabolic disease. Although epidemiological data suggest strong associations between chronic stress exposure and metabolic disease, the etiological mechanisms responsible remain unclear. Mechanistic studies of the influence of chronic social stress are now being conducted in both rodent and nonhuman primate models, and phenotypic results are consistent with those in humans. The advantage of these models is that potential neural mechanisms may be examined and interventions to treat or prevent disease may be developed and tested. Further, circadian disruption and metabolic conditions such as diabetes mellitus could increase susceptibility to other stressors or serve as a stressor itself. Here, we review data from leading investigators discussing the interrelationship between chronic stress and development of metabolic disorders.
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Affiliation(s)
- K L Tamashiro
- Department of Psychiatry & Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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85
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Zuo ZF, Wang W, Niu L, Kou ZZ, Zhu C, Wang W, Zhao XH, Luo DS, Zhang T, Zhang FX, Liu XZ, Wu SX, Li YQ. RU486 (mifepristone) ameliorates cognitive dysfunction and reverses the down-regulation of astrocytic N-myc downstream-regulated gene 2 in streptozotocin-induced type-1 diabetic rats. Neuroscience 2011; 190:156-65. [PMID: 21712075 DOI: 10.1016/j.neuroscience.2011.06.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/06/2011] [Accepted: 06/08/2011] [Indexed: 11/15/2022]
Abstract
Diabetic cognitive dysfunction (DCD), usually accompanied with chronically elevated glucocorticoids and hippocampal astrocytic alterations, is one of the most serious complications in patients with type-1 diabetes. However, the role for chronically elevated glucocorticoids and hippocampal astrocytic activations in DCD remains to be elucidated, and it is not clear whether astrocytic N-myc downstream-regulated gene 2 (NDRG2, involved in cell differentiation and development) participated in DCD. In the present study, three months after streptozotocin (STZ)-induced type-1 diabetes onset, rats showed cognitive impairments in Morris water maze test as well as elevated corticosterone level. Diabetic rats also presented down-regulation of glial fibrillary acidic protein (GFAP, a key indicator of astrocytic reactivity) and NDRG2 in hippocampus revealed by immunohistochemistry staining, real-time PCR and Western blot. Moreover, the diabetic cognitive impairments were ameliorated by 9-day glucocorticoids receptor (GR) blockade with RU486, and the down-regulation of hippocampal NDRG2 and GFAP in diabetic animals was also attenuated by 9-day GR blockade. These results suggest that glucocorticoids-GR system is crucial for DCD, and that astrocytic reactivity and NDRG2 are involved in these processes. Thus, inhibiting GR activation in the hippocampus may be a novel therapeutic strategy for treating DCD.
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Affiliation(s)
- Z-F Zuo
- Department of Anatomy, Histology and Embryology, K.K. Leung Brain Research Center, Fourth Military Medical University, No. 169 West Changle Road, Xi'an 710032, PR China
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86
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Zunszain PA, Anacker C, Cattaneo A, Carvalho LA, Pariante CM. Glucocorticoids, cytokines and brain abnormalities in depression. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:722-9. [PMID: 20406665 PMCID: PMC3513408 DOI: 10.1016/j.pnpbp.2010.04.011] [Citation(s) in RCA: 361] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 04/07/2010] [Accepted: 04/14/2010] [Indexed: 02/09/2023]
Abstract
Major depression (MD) is a common psychiatric disorder with a complex and multifactor aetiology. Potential mechanisms associated with the pathogenesis of this disorder include monoamine deficits, hypothalamic-pituitary-adrenal (HPA) axis dysfunctions, inflammatory and/or neurodegenerative alterations. An increased secretion and reactivity of cortisol together with an altered feedback inhibition are the most widely observed HPA abnormalities in MD patients. Glucocorticoids, such as cortisol, are vital hormones that are released in response to stress, and regulate metabolism and immunity but also neuronal survival and neurogenesis. Interestingly depression is highly prevalent in infectious, autoimmune and neurodegenerative diseases and at the same time, depressed patients show higher levels of pro-inflammatory cytokines. Since communication occurs between the endocrine, immune and central nervous system, an activation of the inflammatory responses can affect neuroendocrine processes, and vice versa. Therefore, HPA axis hyperactivity and inflammation might be part of the same pathophysiological process: HPA axis hyperactivity is a marker of glucocorticoid resistance, implying ineffective action of glucocorticoid hormones on target tissues, which could lead to immune activation; and, equally, inflammation could stimulate HPA axis activity via both a direct action of cytokines on the brain and by inducing glucocorticoid resistance. In addition, increased levels of pro-inflammatory cytokines also induce the production of neurotoxic end products of the tryptophan-kynurenine pathway. Although the evidence for neurodegeneration in MD is controversial, depression is co-morbid with many other conditions where neurodegeneration is present. Since several systems seem to be involved interacting with each other, we cannot unequivocally accept the simple model that glucocorticoids induce neurodegeneration, but rather that elevated cytokines, in the context of glucocorticoid resistance, are probably the offenders. Chronic inflammatory changes in the presence of glucocorticoid resistance may represent a common feature that could be responsible for the enhanced vulnerability of depressed patients to develop neurodegenerative changes later in life. However, further studies are needed to clarify the relative contribution of glucocorticoids and inflammatory signals to MD and other disorders.
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Affiliation(s)
- Patricia A. Zunszain
- Stress, Psychiatry and Immunology Laboratory (SPI-Lab), Department of Psychological Medicine, Institute of Psychiatry, King’s College London, 125 Coldharbour Lane, SE5 9NU, London, United Kingdom
,Corresponding author. (P.A. Zunszain).
| | - Christoph Anacker
- Stress, Psychiatry and Immunology Laboratory (SPI-Lab), Department of Psychological Medicine, Institute of Psychiatry, King’s College London, 125 Coldharbour Lane, SE5 9NU, London, United Kingdom
| | - Annamaria Cattaneo
- Stress, Psychiatry and Immunology Laboratory (SPI-Lab), Department of Psychological Medicine, Institute of Psychiatry, King’s College London, 125 Coldharbour Lane, SE5 9NU, London, United Kingdom
,Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy
| | - Livia A. Carvalho
- Stress, Psychiatry and Immunology Laboratory (SPI-Lab), Department of Psychological Medicine, Institute of Psychiatry, King’s College London, 125 Coldharbour Lane, SE5 9NU, London, United Kingdom
| | - Carmine M. Pariante
- Stress, Psychiatry and Immunology Laboratory (SPI-Lab), Department of Psychological Medicine, Institute of Psychiatry, King’s College London, 125 Coldharbour Lane, SE5 9NU, London, United Kingdom
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87
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Barat P, Tastet S, Vautier V. Impact neuropsychologique à long terme du diabète de type 1 chez l’enfant. Arch Pediatr 2011; 18:432-40. [DOI: 10.1016/j.arcped.2011.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 10/28/2010] [Accepted: 01/24/2011] [Indexed: 10/18/2022]
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Reagan LP. Diabetes as a chronic metabolic stressor: causes, consequences and clinical complications. Exp Neurol 2011; 233:68-78. [PMID: 21320489 DOI: 10.1016/j.expneurol.2011.02.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 01/04/2011] [Accepted: 02/06/2011] [Indexed: 12/30/2022]
Abstract
Diabetes mellitus is an endocrine disorder resulting from inadequate insulin release and/or reduced insulin sensitivity. The complications of diabetes are well characterized in peripheral tissues, but there is a growing appreciation that the complications of diabetes extend to the central nervous system (CNS). One of the potential neurological complications of diabetes is cognitive deficits. Interestingly, the structural, electrophysiological, neurochemical and anatomical underpinnings responsible for cognitive deficits in diabetes are strikingly similar to those observed in animals subjected to chronic stress, as well as in patients with stress-related psychiatric illnesses such as major depressive disorder. Since diabetes is a chronic metabolic stressor, this has led to the suggestion that common mechanistic mediators are responsible for neuroplasticity deficits in both diabetes and depression. Moreover, these common mechanistic mediators may be responsible for the increase in the risk of depressive illness in diabetes patients. In view of these observations, the aims of this review are (1) to describe the neuroplasticity deficits observed in diabetic rodents and patients; (2) to summarize the similarities in the clinical and preclinical studies of depression and diabetes; and (3) to highlight the diabetes-induced neuroplasticity deficits in those brain regions that have been implicated as important pathological centers in depressive illness, namely, the hippocampus, the amygdala and the prefrontal cortex.
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Affiliation(s)
- Lawrence P Reagan
- Department of Pharmacology, Physiology & Neuroscience, University of South Carolina School of Medicine, Columbia, SC 29208, USA.
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89
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Short-term environmental enrichment enhances adult neurogenesis, vascular network and dendritic complexity in the hippocampus of type 1 diabetic mice. PLoS One 2010; 5:e13993. [PMID: 21085588 PMCID: PMC2981567 DOI: 10.1371/journal.pone.0013993] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 10/11/2010] [Indexed: 01/14/2023] Open
Abstract
Background Several brain disturbances have been described in association to type 1 diabetes in humans. In animal models, hippocampal pathological changes were reported together with cognitive deficits. The exposure to a variety of environmental stimuli during a certain period of time is able to prevent brain alterations and to improve learning and memory in conditions like stress, aging and neurodegenerative processes. Methodology/Principal Findings We explored the modulation of hippocampal alterations in streptozotocin-induced type 1 diabetic mice by environmental enrichment. In diabetic mice housed in standard conditions we found a reduction of adult neurogenesis in the dentate gyrus, decreased dendritic complexity in CA1 neurons and a smaller vascular fractional area in the dentate gyrus, compared with control animals in the same housing condition. A short exposure -10 days- to an enriched environment was able to enhance proliferation, survival and dendritic arborization of newborn neurons, to recover dendritic tree length and spine density of pyramidal CA1 neurons and to increase the vascular network of the dentate gyrus in diabetic animals. Conclusions/Significance The environmental complexity seems to constitute a strong stimulator competent to rescue the diabetic brain from neurodegenerative progression.
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90
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Enriched environment prevents memory deficits in type 1 diabetic rats. Behav Brain Res 2010; 217:16-20. [PMID: 20888365 DOI: 10.1016/j.bbr.2010.09.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 09/16/2010] [Accepted: 09/20/2010] [Indexed: 01/09/2023]
Abstract
Studies have shown that an enriched environmental (EE) enhances hippocampal neurogenesis and dendritic branching in rodents, improving the performance in learning and memory task. Diabetes, however, is associated with memory deficits and decreasing in cell proliferation in the hippocampal dentate gyrus (DG), possibly related with higher glucocorticoid levels. Thus, our objective was to investigate the influence of EE on the memory deficits and cell proliferation of diabetic rats. For this, we reared rats for 2 months during early stages of life in standard environments (control rats) or EE. At adulthood, control and EE groups were divided and half of them induced to diabetes by a single injection of streptozotocin, 60 mg/kg, via i.p. Memory deficit was evaluated in these groups in the novel object-placement recognition task 11 days after diabetes induction. BrdU label cells were detected by immunohistochemistry after 3 days of administration to correlate cell proliferation in the DG area and performance in the memory task. Our results showed that EE decreased memory deficits in diabetic-induced rats (p < 0.05). Although cell proliferation in the DG was lower in the diabetic rats, enriched environment did not interfere in this parameter. These findings suggest that enriched environment is able to prevent or delay the development of memory deficits caused by diabetes in rats.
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91
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Guo J, Yu C, Li H, Liu F, Feng R, Wang H, Meng Y, Li Z, Ju G, Wang J. Impaired neural stem/progenitor cell proliferation in streptozotocin-induced and spontaneous diabetic mice. Neurosci Res 2010; 68:329-36. [PMID: 20832431 DOI: 10.1016/j.neures.2010.08.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 08/12/2010] [Accepted: 08/29/2010] [Indexed: 12/28/2022]
Abstract
Diabetes mellitus is associated with adverse complications in many organ systems including the brain. Accumulating evidence indicates that diabetes, regardless of its type, impairs adult neurogenesis in the dentate gyrus (DG) of the hippocampus (HPC). However, the effects of the disease on neurogenesis in the subventricular zone (SVZ) are not well established. We induced diabetes in male NOD/SCID (non-obese diabetic/severe combined immunodeficiency) mice and C57BL/6 mice with a single intraperitoneal injection of streptozotocin (STZ). On day 7 or day 21 after STZ injection mice received the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) for labeling of proliferative cells. Mice were sacrificed 24h later and brain coronal sections were stained with anti-BrdU antibodies. Neural stem/progenitor cell (NSC/NPC) proliferation, as revealed by BrdU-labeled cells, was markedly decreased in the subgranular zone of the DG in STZ-treated diabetic mice. A similar reduction of NSC/NPC proliferation was seen in the SVZ. Reduced DG and SVZ cell proliferation was also found in diabetic NOD mice, a model of spontaneous diabetes, and the reduction was attenuated by bilateral adrenalectomy (Adx). Adx did not alter blood glucose or insulin levels in either prediabetic or diabetic NOD mice, but Adx partly increased mRNA levels of hippocampal and SVZ brain-derived neurotrophic factor (BDNF), a crucial regulator of NSC/NPC proliferation. Moreover, NOD and NOD/SCID mice showed a more rapid reduction of NSC/NPC proliferation than C57BL/6 mice in response to diabetes. Thus, we conclude that diabetes inhibits cell proliferation in both the SVZ and HPC, and inhibition was associated with elevated glucocorticoid levels and reduced BDNF expression.
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Affiliation(s)
- Jun Guo
- Department of Neurology, Tangdu Hospital, Fourth Military Medical University, No. 1 Xin Si Road, Xi'an, Shaanxi Province, China
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Ke X, Schober ME, McKnight RA, O'Grady S, Caprau D, Yu X, Callaway CW, Lane RH. Intrauterine growth retardation affects expression and epigenetic characteristics of the rat hippocampal glucocorticoid receptor gene. Physiol Genomics 2010; 42:177-89. [DOI: 10.1152/physiolgenomics.00201.2009] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Studies in humans and rats suggest that intrauterine growth retardation (IUGR) permanently resets the hypothalamic-pituitary-adrenal (HPA) axis. HPA axis reprogramming may involve persistently altered expression of the hippocampal glucocorticoid receptor (hpGR), an important regulator of HPA axis reactivity. Persistent alteration of gene expression, long after the inciting event, is thought to be mediated by epigenetic mechanisms that affect mRNA and mRNA variant expression. GR mRNA variants in both humans and rats include eleven 5′-end variants and GRα, the predominant 3′-end variant. The 3′-end variants associated with glucocorticoid resistance in humans (GRβ, GRγ, GRA, and GRP) have not been reported in rats. We hypothesized that in the rat hippocampus IUGR would decrease total GR mRNA, increase GRβ, GRγ, GRA, and GRP, and affect epigenetics of the GR gene at birth (D0) and at 21 days of life (D21). IUGR increased hpGR and exon 1.7 hpGR mRNA in males at D0 and D21, associated with increased trimethyl H3/K4 at exon 1.7 at both time points. IUGR also increased hpGRγ in males at D0 and D21, associated with increased acetyl H3/K9 at exon 3 at both time points. hpGRA increased in female IUGR rats at D0 and D21. In addition, our data support the existence of hpGRβ and hpGRP in the rat. IUGR has sex-specific, persistent effects on GR expression and its histone code. We speculate that postnatal changes in hippocampal GR variant and total mRNA expression may underlie IUGR-associated HPA axis reprogramming.
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Affiliation(s)
| | - Michelle E. Schober
- Division of Critical Care, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah
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93
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Hippocampal neurovascular and hypothalamic–pituitary–adrenal axis alterations in spontaneously type 2 diabetic GK rats. Exp Neurol 2010; 222:125-34. [DOI: 10.1016/j.expneurol.2009.12.022] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Revised: 12/01/2009] [Accepted: 12/22/2009] [Indexed: 01/19/2023]
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de Kloet ER. From vasotocin to stress and cognition. Eur J Pharmacol 2009; 626:18-26. [PMID: 19837060 DOI: 10.1016/j.ejphar.2009.10.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2009] [Revised: 10/06/2009] [Accepted: 10/09/2009] [Indexed: 12/16/2022]
Abstract
Sex and stress hormones coordinate experience and behaviour with physiological regulations. In the brain the sex hormones act to promote the repertoire of affiliative and reproductive behaviours. Stress hormones target in particular brain circuits underlying emotional arousal and cognition. To exert these actions the hormones operate in concert with neuropeptide secreting systems. Here I will discuss three examples of hormone action on brain and behaviour. First in the song bird manipulation of brain vasotocin promotes acquisition of a stable stereotyped song pattern. Second in mammal's central glucocorticoid feedback action, initiated and enhanced by vasopressin, is mediated by two types of nuclear receptors that operate in complementary fashion to maintain homeostasis and health. One receptor system, the mineralocorticoid receptors, activates the switch from spatial to habit learning under stressful conditions, while the stress-induced behavioural response is stored in the memory via activation of the glucocorticoid receptors. Third, genetic predisposition and early life experience program neuropeptide and glucocorticoid systems for life with the goal to match with expected future demands. Hence, a mismatch between the early imprinted response modes with later life conditions enhances vulnerability to disease. These three topics have in common that they illustrate how hormones govern plasticity of neural stress circuitry underlying complex behavioural tasks, how upon dysregulation psychiatric disorders may develop for which the individual is predisposed and how such hormone action may promote resilience still present in the diseased brain.
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Affiliation(s)
- E Ronald de Kloet
- Department of Medical Pharmacology, Leiden/Amsterdam Center for Drug Research & Leiden University Medical Center, Leiden, The Netherlands.
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95
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Reisi P, Babri S, Alaei H, Sharifi MR, Mohaddes G, Noorbakhsh SM, Lashgari R. Treadmill running improves long-term potentiation (LTP) defects in streptozotocin-induced diabetes at dentate gyrus in rats. ACTA ACUST UNITED AC 2009; 17:33-8. [PMID: 19646849 DOI: 10.1016/j.pathophys.2009.06.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2009] [Accepted: 06/25/2009] [Indexed: 01/09/2023]
Abstract
OBJECTIVES It has been demonstrated that exercise has neuroprotective effects in the central nervous system (CNS), especially in hippocampus. Previous studies have indicated that diabetes mellitus affects synaptic plasticity in the hippocampus leading to impairments in learning and memory. The aim of this study was to evaluate the effects of treadmill running on synaptic plasticity at dentate gyrus (DG) of streptozotocin-induced diabetic rats. STUDY DESIGN Experimental groups were the control, the diabetes and the diabetes-exercise groups. Long-term potentiation (LTP) in perforant path-DG synapses was assessed (by 400Hz tetanization) in order to investigate the effect of exercise on synaptic plasticity. Field excitatory post-synaptic potential (fEPSP) slope and population spike (PS) amplitude were measured. RESULTS With respect to the control group, fEPSP were significantly decreased in the diabetes group. However, there were no differences between responses of the diabetes-exercise group and the control. CONCLUSION The present results suggest that LTP induction in the dentate gyrus is affected under diabetic conditions and that treadmill running prevents these effects. The data suggest that treadmill running protect against diabetes-induced decrease of learning ability and memory function of the hippocampus.
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Affiliation(s)
- Parham Reisi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
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Oitzl MS, Champagne DL, van der Veen R, de Kloet ER. Brain development under stress: hypotheses of glucocorticoid actions revisited. Neurosci Biobehav Rev 2009; 34:853-66. [PMID: 19631685 DOI: 10.1016/j.neubiorev.2009.07.006] [Citation(s) in RCA: 250] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Revised: 06/05/2009] [Accepted: 07/16/2009] [Indexed: 12/23/2022]
Abstract
One of the conundrums in today's stress research is why some individuals flourish and others perish under similar stressful conditions. It is recognized that this individual variability in adaptation to stress depends on the outcome of the interaction of genetic and cognitive/emotional inputs in which glucocorticoid hormones and receptors play a crucial role. Hence one approach towards understanding individual variation in stress coping is how glucocorticoid actions can change from protective to harmful. To address this question we focus on four hypotheses that are connected and not mutual exclusive. First, the classical Glucocorticoid Cascade Hypothesis, in which the inability to cope with chronic stress causes a vicious cycle of excess glucocorticoid and downregulation of glucocorticoid receptors (GR) in the hippocampus triggering a feed-forward cascade of degeneration and disease. Second, the Balance Hypothesis, which takes also the limbic mineralocorticoid receptors (MR) into account and proposes that an integral limbic MR:GR imbalance is causal to altered processing of information in circuits underlying fear, reward, social behaviour and resilience, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and impairment of behavioural adaptation. The MR:GR balance is altered by gene variants of these receptor complexes and experience-related factors, which can induce lasting epigenetic changes in the expression of these receptors. A particular potent epigenetic stimulus is the maternal environment which is fundamental for the Maternal Mediation Hypothesis. The outcome of perinatal gene x environment interaction, and thus of MR:GR-mediated functions depends however, on the degree of 'matching' with environmental demands in later life. The Predictive Adaptation Hypothesis therefore presents a conceptual framework to examine the role of glucocorticoids in understanding individual phenotypic differences in stress-related behaviours over the lifespan.
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Affiliation(s)
- Melly S Oitzl
- Division of Medical Pharmacology, Leiden/Amsterdam Centre for Drug Research (LACDR)/Leiden University Medical Centre (LUMC), University of Leiden, Einsteinweg 55, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
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