1901
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Lo C, Zimmermann C, Rydall A, Walsh A, Jones JM, Moore MJ, Shepherd FA, Gagliese L, Rodin G. Longitudinal Study of Depressive Symptoms in Patients With Metastatic Gastrointestinal and Lung Cancer. J Clin Oncol 2010; 28:3084-9. [DOI: 10.1200/jco.2009.26.9712] [Citation(s) in RCA: 169] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Purpose Although early intervention is increasingly advocated to prevent and relieve distress in patients with metastatic cancer, the risk factors for such symptoms and their trajectory are not well established. We therefore conducted a longitudinal study to determine the course and predictors of depressive symptoms. Patients and Methods Patients (N = 365) with metastatic gastrointestinal or lung cancer completed measures of physical distress, self-esteem, attachment security, spiritual well-being, social support, hopelessness, and depression at baseline; physical distress, social support, hopelessness, and depression were subsequently assessed at 2-month intervals. Results Of the sample, 35% reported at least mild depressive symptoms, with 16% reporting moderate to severe depressive symptoms that persisted in at least one third of such individuals. Moderate to severe depressive symptoms were almost three times more common in the final 3 months of life than ≥ 1 year before death. Predictors of depressive symptoms included younger age, antidepressant use at baseline, lower self-esteem and spiritual well-being, and greater attachment anxiety, hopelessness, physical burden of illness, and proximity to death. The combination of greater physical suffering and psychosocial vulnerability put individuals at greatest risk for depression. Conclusion Depressive symptoms in advanced cancer patients are relatively common and may arise as a final common pathway of distress in response to psychosocial vulnerabilities, physical suffering, and proximity to death. These findings support the need for an integrated approach to address emotional and physical distress in this population and to determine whether early intervention may prevent depression at the end of life.
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Affiliation(s)
- Christopher Lo
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Camilla Zimmermann
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Anne Rydall
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Andrew Walsh
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Jennifer M. Jones
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Malcolm J. Moore
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Frances A. Shepherd
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Lucia Gagliese
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
| | - Gary Rodin
- From Princess Margaret Hospital, Campbell Family Cancer Research Institute and Ontario Cancer Institute, and Toronto General Research Institute, University Health Network; University of Toronto; and York University, Toronto, Ontario, Canada
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1902
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Acute reversible inactivation of the ventral medial prefrontal cortex induces antidepressant-like effects in rats. Behav Brain Res 2010; 214:437-42. [PMID: 20600346 DOI: 10.1016/j.bbr.2010.06.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2010] [Revised: 06/08/2010] [Accepted: 06/13/2010] [Indexed: 11/24/2022]
Abstract
The ventral medial prefrontal cortex (vMPFC) has direct connections to subcortical, diencephalic and brainstem structures that have been closely related to depression. However, studies aimed at investigating the role of the vMPFC in the neurobiology of depression have produced contradictory results. Moreover, the precise involvement of vMPFC anatomic subdivisions, the prelimbic (PL) and the infralimbic (IL) cortices, in regulating depressive-like behavior have been poorly investigated. The forced swimming test (FST) is a widely employed animal model aimed at detecting antidepressant-like effects. Therefore, to further investigate a possible involvement of the vMFPC in depressive-like behavior, rats bilaterally implanted with cannulae aimed at the PL or IL prefrontal cortices were submitted to 15 min of forced swimming (pre-test) followed, 24h later, by a 5-min swimming session (test), where immobility time was registered. Synaptic transmission in these regions was temporarily inhibited using local microinjection of cobalt chloride at different periods of the experimental procedure (before or after the pre-test or before the test). PL inactivation decreased immobility time independently of the time of the injection. In the IL, inactivation induced a significant antidepressant-like effect when performed immediately before the pre-test or before the test, but not after the pre-test. These results suggest that activation of the vMPFC is important for the behavioral changes observed in rats submitted to the FST. They further indicate that, although both the PL and IL cortices are involved in these effects, they may play different roles.
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1903
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Iñiguez SD, Vialou V, Warren BL, Cao JL, Alcantara LF, Davis LC, Manojlovic Z, Neve RL, Russo SJ, Han MH, Nestler EJ, Bolaños-Guzmán CA. Extracellular signal-regulated kinase-2 within the ventral tegmental area regulates responses to stress. J Neurosci 2010; 30:7652-63. [PMID: 20519540 PMCID: PMC2895424 DOI: 10.1523/jneurosci.0951-10.2010] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Revised: 04/09/2010] [Accepted: 04/15/2010] [Indexed: 12/12/2022] Open
Abstract
Neurotrophic factors and their signaling pathways have been implicated in the neurobiological adaptations in response to stress and the regulation of mood-related behaviors. A candidate signaling molecule implicated in mediating these cellular responses is the extracellular signal-regulated kinase (ERK1/2), although its functional role in mood regulation remains to be fully elucidated. Here we show that acute (1 d) or chronic (4 weeks) exposure to unpredictable stress increases phosphorylation of ERK1/2 and of two downstream targets (ribosomal S6 kinase and mitogen- and stress-activated protein kinase 1) within the ventral tegmental area (VTA), an important substrate for motivated behavior and mood regulation. Using herpes simplex virus-mediated gene transfer to assess the functional significance of this ERK induction, we show that overexpressing ERK2 within the VTA increases susceptibility to stress as measured in the forced swim test, responses to unconditioned nociceptive stimuli, and elevated plus maze in Sprague Dawley male rats, and in the tail suspension test and chronic social defeat stress procedure in C57BL/6 male mice. In contrast, blocking ERK2 activity in the VTA produces stress-resistant behavioral responses in these same assays and also blocks a chronic stress-induced reduction in sucrose preference. The effects induced by ERK2 blockade were accompanied by decreases in the firing frequency of VTA dopamine neurons, an important electrophysiological hallmark of resilient-like behavior. Together, these results strongly implicate a role for ERK2 signaling in the VTA as a key modulator of responsiveness to stress and mood-related behaviors.
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MESH Headings
- Action Potentials/physiology
- Analysis of Variance
- Animals
- Animals, Genetically Modified
- Behavior, Animal/physiology
- Dominance-Subordination
- Electroshock/adverse effects
- Escape Reaction/physiology
- Food Preferences/physiology
- Gene Expression Regulation, Enzymologic/physiology
- Green Fluorescent Proteins/genetics
- Hindlimb Suspension/methods
- In Vitro Techniques
- Male
- Maze Learning/physiology
- Mice
- Mice, Inbred C57BL
- Mitogen-Activated Protein Kinase 1/genetics
- Mitogen-Activated Protein Kinase 1/metabolism
- Motor Activity
- Neurons/physiology
- Oncogene Proteins, Fusion
- Pain/enzymology
- Pain/etiology
- Pain/pathology
- Phosphorylation/physiology
- Rats
- Rats, Sprague-Dawley
- Receptors, Fibroblast Growth Factor
- Signal Transduction/physiology
- Simplexvirus/physiology
- Stress, Psychological/enzymology
- Stress, Psychological/etiology
- Stress, Psychological/pathology
- Sucrose/administration & dosage
- Sweetening Agents/administration & dosage
- Swimming/psychology
- Time Factors
- Transduction, Genetic/methods
- Tyrosine 3-Monooxygenase/metabolism
- Ventral Tegmental Area/enzymology
- Ventral Tegmental Area/pathology
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Affiliation(s)
- Sergio D. Iñiguez
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
| | | | - Brandon L. Warren
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
| | - Jun-Li Cao
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029-6574, and
| | - Lyonna F. Alcantara
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
| | - Lindsey C. Davis
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
| | - Zarko Manojlovic
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
| | - Rachael L. Neve
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307
| | | | - Ming-Hu Han
- Fishberg Department of Neuroscience and
- Department of Pharmacology and Systems Therapeutics, Mount Sinai School of Medicine, New York, New York 10029-6574, and
| | | | - Carlos A. Bolaños-Guzmán
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida 32306-4301
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1904
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Iñiguez SD, Warren BL, Bolaños-Guzmán CA. Short- and long-term functional consequences of fluoxetine exposure during adolescence in male rats. Biol Psychiatry 2010; 67:1057-66. [PMID: 20172503 PMCID: PMC2868075 DOI: 10.1016/j.biopsych.2009.12.033] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2009] [Revised: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 12/15/2022]
Abstract
BACKGROUND Fluoxetine (FLX), a selective serotonin reuptake inhibitor, is prescribed for the treatment of major depressive disorder in young populations. Here, we explore the short- and long-term consequences of adolescent exposure to FLX on behavioral reactivity to emotion-eliciting stimuli. METHODS Adolescent male rats received FLX (10 mg/kg) twice daily for 15 consecutive days (postnatal days 35-49). The influence of FLX on behavioral reactivity to rewarding and aversive stimuli was assessed 24 hours (short-term) or 3 weeks after FLX treatment (long-term). A separate group of adult rats was also treated with FLX (postnatal days 65-79) and responsiveness to forced swimming was assessed at identical time intervals as with the adolescents. RESULTS Fluoxetine exposure during adolescence resulted in long-lasting decreases in behavioral reactivity to forced swimming stress and enhanced sensitivity to sucrose and to anxiety-eliciting situations in adulthood. The FLX-induced anxiety-like behavior was alleviated by re-exposure to FLX in adulthood. Fluoxetine treatment during adolescence also impaired sexual copulatory behaviors in adulthood. Fluoxetine-treated adult rats did not show changes in behavioral reactivity to forced swim stress as observed in those treated during adolescence and tested in adulthood. CONCLUSIONS Treating adolescent rats with FLX results in long-lived complex outputs regulated by the emotional valence of the stimulus, the environment in which it is experienced, and the brain circuitry likely being engaged by it. Our findings highlight the need for further research to improve our understanding of the alterations that psychotropic exposure may induce on the developing nervous system and the potential enduring effects resulting from such treatments.
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Affiliation(s)
- Sergio D Iñiguez
- Department of Psychology, Florida State University, Tallahassee, FL 32306-4301, USA
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1905
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Cattaneo A, Sesta A, Calabrese F, Nielsen G, Riva MA, Gennarelli M. The expression of VGF is reduced in leukocytes of depressed patients and it is restored by effective antidepressant treatment. Neuropsychopharmacology 2010; 35:1423-8. [PMID: 20164831 PMCID: PMC3055467 DOI: 10.1038/npp.2010.11] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Major depression is a disease characterized by an inability of neuronal systems to show appropriate adaptive plasticity especially under challenging conditions, such as stress. Conversely, pharmacological intervention may normalize such defects through the modulation of factors that might act in concert for the functional recovery of depressed patients, like the neuropeptide VGF, which has previously shown to possess antidepressant like activity. We analyzed VGF mRNA levels in the brain of rodents exposed to stress or treated with antidepressant drugs. In addition, we assessed VGF expression in leukocytes obtained from 25 drug-free depressed patients before and during antidepressant treatment. We found a persistent reduction of VGF expression after exposure to prenatal stress and an upregulation of its levels following chronic treatment with different antidepressant drugs. Moreover, VGF mRNA levels were significantly reduced in drug-free depressed patients, as compared with controls, and were modulated in response to effective antidepressant treatment. Our data provide further support to the role of VGF in mood disorders and suggest that VGF could be a more specific biomarker for treatment responsiveness.
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Affiliation(s)
- Annamaria Cattaneo
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Antonella Sesta
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Francesca Calabrese
- Department of Pharmacological Sciences, Center of Neuropharmacology, Università degli studi di Milano, Milan, Italy
| | - Gabriela Nielsen
- Psychiatric Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy
| | - Marco Andrea Riva
- Department of Pharmacological Sciences, Center of Neuropharmacology, Università degli studi di Milano, Milan, Italy,Center of Excellence on Neurodegenerative Diseases, Università degli studi di Milano, Milan, Italy
| | - Massimo Gennarelli
- Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy,Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Brescia, Italy,Division of Biology and Genetics, Department of Biomedical Sciences and Biotechnologies, University of Brescia, Genetics Unit, IRCCS San Giovanni di Dio, Fatebenefratelli, Viale Europa 11, Brescia 25123, Italy, Tel: +39 030 3501453, Fax: +39 030 3501592, E-mail:
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1906
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Matrisciano F, Modafferi AM, Togna GI, Barone Y, Pinna G, Nicoletti F, Scaccianoce S. Repeated anabolic androgenic steroid treatment causes antidepressant-reversible alterations of the hypothalamic–pituitary–adrenal axis, BDNF levels and behavior. Neuropharmacology 2010; 58:1078-84. [DOI: 10.1016/j.neuropharm.2010.01.015] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/25/2010] [Accepted: 01/26/2010] [Indexed: 01/26/2023]
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1907
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Kovács Z, Czurkó A, Kékesi KA, Juhász G. Clomipramine increases the incidence and duration of spike-wave discharges in freely moving WAG/Rij rats. Epilepsy Res 2010; 90:167-70. [DOI: 10.1016/j.eplepsyres.2010.02.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2009] [Revised: 01/19/2010] [Accepted: 02/22/2010] [Indexed: 01/22/2023]
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1908
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1909
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Kim JM, Kim SY, Bae KY, Kim SW, Shin IS, Yang SJ, Song YH, Yoon JS. Apolipoprotein e4 genotype and depressive symptoms as risk factors for dementia in an older korean population. Psychiatry Investig 2010; 7:135-40. [PMID: 20577623 PMCID: PMC2890868 DOI: 10.4306/pi.2010.7.2.135] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Revised: 02/25/2010] [Accepted: 02/25/2010] [Indexed: 12/05/2022] Open
Abstract
OBJECTIVE Growing evidence suggests the separate associations of apolipoprotein E e4 allele (apo E4) and depression with incident dementia. This study investigated the separate and combined effects of apo E4 and depression on the incidence of dementia in both men and women. METHODS Of 625 elderly without dementia at baseline, 518 (83%) were followed over a 2.4-year period and were assessed clinically for incident dementia. The apo E polymorphism was ascertained, and depression was identified using the Korean version of the Geriatric Depression Scale (KGDS). Covariates included age, gender, education, disability, alcohol history, physical activity, and vascular risk factors. RESULTS The incidence of dementia was significantly higher in elderly Koreans with both apo E4 and depression compared to those without both factors [adjusted odds ratio (95% CI)=5.85 (1.77-19.38)]. This interaction was significant in men (p=0.049), but not in women (p=0.354). CONCLUSION Depressed elderly people are at great risk for incident dementia in the presence of apo E4. Potential gender differences require further evaluation.
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Affiliation(s)
- Jae-Min Kim
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Seon-Young Kim
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Kyung-Yeol Bae
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Sung-Wan Kim
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Il-Seon Shin
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Su-Jin Yang
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Young-Heon Song
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
| | - Jin-Sang Yoon
- Department of Psychiatry, Chonnam National University Medical School, Gwangju, Korea
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1910
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Tian WM, Zhang KR, Zhang J, Shen Y, Xu Q. Association between the Epidermal Growth Factor Gene and Intelligence in Major Depression Patients. ACTA ACUST UNITED AC 2010; 25:105-8. [DOI: 10.1016/s1001-9294(10)60031-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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1911
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Wemm S, Koone T, Blough ER, Mewaldt S, Bardi M. The role of DHEA in relation to problem solving and academic performance. Biol Psychol 2010; 85:53-61. [PMID: 20562010 DOI: 10.1016/j.biopsycho.2010.05.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 05/06/2010] [Accepted: 05/19/2010] [Indexed: 12/16/2022]
Abstract
Dehydroepiandrosterone (DHEA) has been correlated with lower susceptibility to anxiety and mood disturbance. Since coping styles have been shown to be a critical component of academic achievement, we aimed to assess the relationship between DHEA and coping mechanisms in college students. Participants were recruited and tested twice, one week apart. Cardiovascular measurements and saliva samples were taken for each participant. The behavioral task consisted of a set of anagrams of increasing difficulty (possible to impossible). American College Testing (ACT) scores, number of college courses failed and dropped along with current grade point average (GPA) were recorded. Results indicated that successfully coping with challenging tasks is a function of behavioral flexibility and physiological neuroprotection. When presented with challenging tasks, individuals who vary their behavioral response to fit the task's demands have the lowest probability of failing the task. The same individuals also have higher levels of resiliency hormones, demonstrated by a lower ratio of cortisol versus DHEA levels.
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Affiliation(s)
- Stephanie Wemm
- Psychology Department, Marshall University, One John Marshall Drive, Huntington, WV 25575, USA
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1912
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DeltaFosB in brain reward circuits mediates resilience to stress and antidepressant responses. Nat Neurosci 2010; 13:745-52. [PMID: 20473292 DOI: 10.1038/nn.2551] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Accepted: 04/12/2010] [Indexed: 12/12/2022]
Abstract
In contrast with the many studies of stress effects on the brain, relatively little is known about the molecular mechanisms of resilience, the ability of some individuals to escape the deleterious effects of stress. We found that the transcription factor DeltaFosB mediates an essential mechanism of resilience in mice. Induction of DeltaFosB in the nucleus accumbens, an important brain reward-associated region, in response to chronic social defeat stress was both necessary and sufficient for resilience. DeltaFosB induction was also required for the standard antidepressant fluoxetine to reverse behavioral pathology induced by social defeat. DeltaFosB produced these effects through induction of the GluR2 AMPA glutamate receptor subunit, which decreased the responsiveness of nucleus accumbens neurons to glutamate, and through other synaptic proteins. Together, these findings establish a previously unknown molecular pathway underlying both resilience and antidepressant action.
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1913
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Fishback JA, Robson MJ, Xu YT, Matsumoto RR. Sigma receptors: potential targets for a new class of antidepressant drug. Pharmacol Ther 2010; 127:271-82. [PMID: 20438757 DOI: 10.1016/j.pharmthera.2010.04.003] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 03/29/2010] [Indexed: 11/29/2022]
Abstract
Despite the widespread and devastating impact of depression on society, our current understanding of its pathogenesis is limited. Likewise, existing treatments are inadequate, providing relief to only a subset of people suffering from depression. The search for more effective antidepressant drugs includes the investigation of new molecular targets. Among them, current data suggests that sigma receptors are involved in multiple processes effecting antidepressant-like actions in vivo and in vitro. This review summarizes accumulated evidence supporting a role for sigma receptors in antidepressant effects and provides a conceptual framework for delineating their potential roles over the course of antidepressant treatment.
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Affiliation(s)
- James A Fishback
- School of Pharmacy, West Virginia University, Morgantown, WV, USA
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1914
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Shishkina GT, Kalinina TS, Berezova IV, Bulygina VV, Dygalo NN. Resistance to the development of stress-induced behavioral despair in the forced swim test associated with elevated hippocampal Bcl-xl expression. Behav Brain Res 2010; 213:218-24. [PMID: 20457187 DOI: 10.1016/j.bbr.2010.05.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Revised: 04/30/2010] [Accepted: 05/01/2010] [Indexed: 01/27/2023]
Abstract
Stress may predispose individuals toward depression through down-regulation of neurogenesis and increase in apoptosis in the brain. However, many subjects show high resistance to stress in relation to psychopathology. In the present study, we assessed the possibility that individual-specific patterns of gene expression associated with cell survival and proliferation may be among the molecular factors underlying stress resilience. Brain-derived neurotrophic factor (BDNF), anti-apoptotic B cell lymphoma like X (Bcl-xl) and pro-apoptotic bcl2-associated X protein (Bax) expression were determined in the hippocampus and frontal cortex of rats naturally differed in despair-like behavior in the forced swim test. In the hippocampus, BDNF messenger RNA (mRNA) level was significantly down-regulated 2h after the forced swim test exposure, and at this time point, Bcl-xl mRNA and protein levels were significantly higher in stressed than in untested animals. The ratios of hippocampal Bcl-xl to Bax mRNA negatively correlated with the total time spent immobile in the test. When animals were divided in two groups according to immobility responses in two consecutive swim sessions and designated as stress resilient if their immobility time did not increase in the second session as it did in stress sensitive rats, it was found that resilient rats had significantly higher Bcl-xl/Bax ratios in the hippocampus than stress sensitive animals. The data suggest that naturally occurring variations in the Bcl-xl/Bax ratio in the hippocampus may contribute to individual differences in vulnerability to stress-induced depression-like behaviors.
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Affiliation(s)
- Galina T Shishkina
- Functional Neurogenomics Laboratory, Institute of Cytology and Genetics, Lavrentjev Av. 10, Novosibirsk, Russia
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1915
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1916
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Abstract
Antidepressant drugs represent one of the main forms of effective treatment for the amelioration of depressive symptoms. Most available antidepressants increase extracellular levels of monoamines. However, it is now recognized that monoamine levels and availability are only part of the story, and that antidepressants whose mechanism of action is mainly based on the modulation of monoaminergic systems may not be able to satisfy the unmet needs of depression. Therefore, a number of compounds, developed for their potential antidepressant activity, are endowed with putative mechanisms of action not affecting traditional monoamine targets. This article briefly reviews, within a mechanistic perspective, the pharmacological profiles of representative antidepressants from each class, including monoamine oxidase inhibitors, tricyclics, norepinephrine reuptake inhibitors, selective serotonin reuptake inhibitors, norepinephrine and serotonin reuptake inhibitors, antidepressants interacting with dopaminergic, melatonergic, glutamatergic, or neuropeptide systems. The undesirable side effects of currently used antidepressants, which can often be a reason for lack of compliance, are also considered.
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1917
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Ampuero E, Rubio FJ, Falcon R, Sandoval M, Diaz-Veliz G, Gonzalez RE, Earle N, Dagnino-Subiabre A, Aboitiz F, Orrego F, Wyneken U. Chronic fluoxetine treatment induces structural plasticity and selective changes in glutamate receptor subunits in the rat cerebral cortex. Neuroscience 2010; 169:98-108. [PMID: 20417256 DOI: 10.1016/j.neuroscience.2010.04.035] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2010] [Revised: 04/14/2010] [Accepted: 04/16/2010] [Indexed: 12/16/2022]
Abstract
It has been postulated that chronic administration of antidepressant drugs induces delayed structural and molecular adaptations at glutamatergic forebrain synapses that might underlie mood improvement. To gain further insight into these changes in the cerebral cortex, rats were treated with fluoxetine (flx) for 4 weeks. These animals showed decreased anxiety and learned helplessness. N-methyl-d-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor subunit levels (NR1, NR2A, NR2B, GluR1 and GluR2) were analysed in the forebrain by both western blot of homogenates and immunohistochemistry. Both methods demonstrated an upregulation of NR2A, GluR1 and GluR2 that was especially significant in the retrosplenial granular b cortex (RSGb). However, when analysing subunit content in postsynaptic densities and synaptic membranes, we found increases of NR2A and GluR2 but not GluR1. Instead, GluR1 was augmented in a microsomal fraction containing intracellular membranes. NR1 and GluR2 were co-immunoprecipitated from postsynaptic densities and synaptic membranes. In the immunoprecipitates, NR2A was increased while GluR1 was decreased supporting a change in receptor stoichiometry. The changes of subunit levels were associated with an upregulation of dendritic spine density and of large, mushroom-type spines. These molecular and structural adaptations might be involved in neuronal network stabilization following long-term flx treatment.
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Affiliation(s)
- E Ampuero
- Laboratorio de Neurociencias, Universidad de los Andes, Santiago, Chile
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1918
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Massa SM, Yang T, Xie Y, Shi J, Bilgen M, Joyce JN, Nehama D, Rajadas J, Longo FM. Small molecule BDNF mimetics activate TrkB signaling and prevent neuronal degeneration in rodents. J Clin Invest 2010; 120:1774-85. [PMID: 20407211 DOI: 10.1172/jci41356] [Citation(s) in RCA: 303] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 02/17/2010] [Indexed: 02/01/2023] Open
Abstract
Brain-derived neurotrophic factor (BDNF) activates the receptor tropomyosin-related kinase B (TrkB) with high potency and specificity, promoting neuronal survival, differentiation, and synaptic function. Correlations between altered BDNF expression and/or function and mechanism(s) underlying numerous neurodegenerative conditions, including Alzheimer disease and traumatic brain injury, suggest that TrkB agonists might have therapeutic potential. Using in silico screening with a BDNF loop-domain pharmacophore, followed by low-throughput in vitro screening in mouse fetal hippocampal neurons, we have efficiently identified small molecules with nanomolar neurotrophic activity specific to TrkB versus other Trk family members. Neurotrophic activity was dependent on TrkB and its downstream targets, although compound-induced signaling activation kinetics differed from those triggered by BDNF. A selected prototype compound demonstrated binding specificity to the extracellular domain of TrkB. In in vitro models of neurodegenerative disease, it prevented neuronal degeneration with efficacy equal to that of BDNF, and when administered in vivo, it caused hippocampal and striatal TrkB activation in mice and improved motor learning after traumatic brain injury in rats. These studies demonstrate the utility of loop modeling in drug discovery and reveal what we believe to be the first reported small molecules derived from a targeted BDNF domain that specifically activate TrkB.We propose that these compounds constitute a novel group of tools for the study of TrkB signaling and may provide leads for developing new therapeutic agents for neurodegenerative diseases.
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Affiliation(s)
- Stephen M Massa
- Department of Neurology and Laboratory for Computational Neurochemistry and Drug Discovery, UCSF, San Francisco, California, USA
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1919
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Spadin, a sortilin-derived peptide, targeting rodent TREK-1 channels: a new concept in the antidepressant drug design. PLoS Biol 2010; 8:e1000355. [PMID: 20405001 PMCID: PMC2854129 DOI: 10.1371/journal.pbio.1000355] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 03/08/2010] [Indexed: 11/19/2022] Open
Abstract
Current antidepressant treatments are inadequate for many individuals, and when they are effective, they require several weeks of administration before a therapeutic effect can be observed. Improving the treatment of depression is challenging. Recently, the two-pore domain potassium channel TREK-1 has been identified as a new target in depression, and its antagonists might become effective antidepressants. In mice, deletion of the TREK-1 gene results in a depression-resistant phenotype that mimics antidepressant treatments. Here, we validate in mice the antidepressant effects of spadin, a secreted peptide derived from the propeptide generated by the maturation of the neurotensin receptor 3 (NTSR3/Sortilin) and acting through TREK-1 inhibition. NTSR3/Sortilin interacted with the TREK-1 channel, as shown by immunoprecipitation of TREK-1 and NTSR3/Sortilin from COS-7 cells and cortical neurons co-expressing both proteins. TREK-1 and NTSR3/Sortilin were colocalized in mouse cortical neurons. Spadin bound specifically to TREK-1 with an affinity of 10 nM. Electrophysiological studies showed that spadin efficiently blocked the TREK-1 activity in COS-7 cells, cultured hippocampal pyramidal neurons, and CA3 hippocampal neurons in brain slices. Spadin also induced in vivo an increase of the 5-HT neuron firing rate in the Dorsal Raphe Nucleus. In five behavioral tests predicting an antidepressant response, spadin-treated mice showed a resistance to depression as found in TREK-1 deficient mice. More importantly, an intravenous 4-d treatment with spadin not only induced a strong antidepressant effect but also enhanced hippocampal phosphorylation of CREB protein and neurogenesis, considered to be key markers of antidepressant action after chronic treatment with selective serotonin reuptake inhibitors. This work also shows the development of a reliable method for dosing the propeptide in serum of mice by using AlphaScreen technology. These findings point out spadin as a putative antidepressant of new generation with a rapid onset of action. Spadin can be regarded as the first natural antidepressant peptide identified. It corresponds to a new concept to address the treatment of depression.
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1920
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Bartolomucci A, Carola V, Pascucci T, Puglisi-Allegra S, Cabib S, Lesch KP, Parmigiani S, Palanza P, Gross C. Increased vulnerability to psychosocial stress in heterozygous serotonin transporter knockout mice. Dis Model Mech 2010; 3:459-70. [PMID: 20371729 DOI: 10.1242/dmm.004614] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Epidemiological evidence links exposure to stressful life events with increased risk for mental illness. However, there is significant individual variability in vulnerability to environmental risk factors, and genetic variation is thought to play a major role in determining who will become ill. Several studies have shown, for example, that individuals carrying the S (short) allele of the serotonin transporter (5-HTT) gene-linked polymorphic region (5-HTTLPR) have an increased risk for major depression following exposure to stress in adulthood. Identifying the molecular mechanisms underlying this gene-by-environment risk factor could help our understanding of the individual differences in resilience to stress. Here, we present a mouse model of the 5-HTT-by-stress risk factor. Wild-type and heterozygous 5-HTT knockout male mice were subjected to three weeks of chronic psychosocial stress. The 5-HTT genotype did not affect the physiological consequences of stress as measured by changes in body temperature, body weight gain and plasma corticosterone. However, when compared with wild-type littermates, heterozygous 5-HTT knockout mice experiencing high levels of stressful life events showed significantly depressed locomotor activity and increased social avoidance toward an unfamiliar male in a novel environment. Heterozygous 5-HTT knockout mice exposed to high stress also showed significantly lower levels of serotonin turnover than wild-type littermates, selectively in the frontal cortex, which is a structure that is known to control fear and avoidance responses, and that is implicated in susceptibility to depression. These data may serve as a useful animal model for better understanding the increased vulnerability to stress reported in individuals carrying the 5-HTTLPR S allele, and suggest that social avoidance represents a behavioral endophenotype of the interaction between 5-HTT and stress.
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Affiliation(s)
- Alessandro Bartolomucci
- Department of Evolutionary and Functional Biology, University of Parma, viale G.P. Usberti 11A, Parma, Italy.
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1921
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Narasimhan M, Campbell N. A tale of two comorbidities: Understanding the neurobiology of depression and pain. Indian J Psychiatry 2010; 52:127-30. [PMID: 20838499 PMCID: PMC2927881 DOI: 10.4103/0019-5545.64586] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The comorbidity of chronic pain and depression has been consistently associated with a poor prognosis and greater disability in patients as compared to those suffering from each illness alone. This further has implications on significant financial costs to the patients and to our society. The biological underpinnings of major depression and chronic pain have considerable overlap in the areas of genetic, structural, functional, neuroendocrine and neurotransmitter functionality. Although the field has evolved in the past decade, more efforts should now focus on understanding the biological underpinnings of this shared comorbidity, while shedding light on treatment implications for these two devastating conditions.
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Affiliation(s)
- Meera Narasimhan
- Research and Scientific Initiatives, Department of Neuropsychiatry and Behavioral Science, University of South Carolina School of Medicine
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1922
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Abstract
Depression is the most common mental illness in the elderly, with an estimated 15% of the elderly population living in the community having clinically significant depressive symptoms. It is of medical and social importance as it is associated with increased morbidity and mortality, poor quality of life and increased social dependence. Recognition of depression in this age group has been found to be poor, with more patients presenting with somatic physical symptoms. Treatment can also be difficult compared with younger patients, with increased prevalence of side effects of medication, polypharmacy and poor compliance. Primary care practitioners are therefore crucial in the detection and early instigation of appropriate treatment. This article looks at the risk factors, presentation and treatment options for depression in the elderly age group.
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Affiliation(s)
- Emma Funnell
- Academic GP Registrar, Department of Primary Care, University of Liverpool
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1923
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Freitas AE, Budni J, Lobato KR, Binfaré RW, Machado DG, Jacinto J, Veronezi PO, Pizzolatti MG, Rodrigues ALS. Antidepressant-like action of the ethanolic extract from Tabebuia avellanedae in mice: evidence for the involvement of the monoaminergic system. Prog Neuropsychopharmacol Biol Psychiatry 2010; 34:335-43. [PMID: 20026371 DOI: 10.1016/j.pnpbp.2009.12.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 11/28/2009] [Accepted: 12/12/2009] [Indexed: 02/06/2023]
Abstract
The antidepressant-like effect of the ethanolic extract obtained from barks of Tabebuia avellanedae, a plant widely employed in folk medicine, was investigated in two predictive models of depression: forced swimming test (FST) and tail suspension test (TST) in mice. Additionally, the mechanisms involved in this antidepressant-like action and the effects of the association of the extract with the antidepressants fluoxetine, desipramine and bupropion in the TST were investigated. The extract from T. avellanedae produced an antidepressant-like effect, in the FST (100 mg/kg, p.o.) and in the TST (10-300 mg/kg, p.o.), without accompanying changes in ambulation when assessed in the open-field test. The anti-immobility effect of the extract (30 mg/kg, p.o.) in the TST was prevented by pre-treatment of mice with ketanserin (5 mg/kg, i.p., a preferential 5-HT(2A) receptor antagonist), prazosin (1 mg/kg, i.p., an alpha(1)-adrenoceptor antagonist), yohimbine (1 mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), propranolol (2 mg/kg, i.p., a beta-adrenoceptor antagonist), sulpiride (50 mg/kg, i.p., a dopamine D(2) receptor antagonist) and SCH23390 (0.05 mg/kg, s.c., a dopamine D(1) receptor antagonist). The combined administration of a subeffective dose of WAY100635 (0.1 mg/kg, s.c., a selective 5-HT(1A) receptor antagonist) and a subeffective dose of the extract (1 mg/kg, p.o.) produced a significant reduction in the immobility time in the TST. In addition, the combination of fluoxetine (1 mg/kg, p.o.), desipramine (0.1 mg/kg, p.o.), or bupropion (1 mg/kg, p.o.) with a subeffective dose of the extract (1 mg/kg, p.o.) produced a synergistic antidepressant-like effect in the TST, without causing hyperlocomotion in the open-field test. It may be concluded that the extract from T. avellanedae produces an antidepressant-like effect in the FST and in the TST that is dependent on the monoaminergic system. Taken together, our results suggest that T. avellanedae deserves further investigation as a putative alternative therapeutic tool that could help the conventional pharmacotherapy of depression.
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Affiliation(s)
- Andiara E Freitas
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Campus Universitário-Trindade-88040-900, Florianópolis-SC, Brazil
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1924
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Aboukhatwa M, Dosanjh L, Luo Y. Antidepressants are a rational complementary therapy for the treatment of Alzheimer's disease. Mol Neurodegener 2010; 5:10. [PMID: 20226030 PMCID: PMC2845130 DOI: 10.1186/1750-1326-5-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 03/12/2010] [Indexed: 12/17/2022] Open
Abstract
There is a high prevalence rate (30-50%) of Alzheimer's disease (AD) and depression comorbidity. Depression can be a risk factor for the development of AD or it can be developed secondary to the neurodegenerative process. There are numerous documented diagnosis and treatment challenges for the patients who suffer comorbidity between these two diseases. Meta analysis studies have provided evidence for the safety and efficacy of antidepressants in treatment of depression in AD patients. Preclinical and clinical studies show the positive role of chronic administration of selective serotonin reuptake inhibitor (SSRI) antidepressants in hindering the progression of the AD and improving patient performance. A number of clinical studies suggest a beneficial role of combinatorial therapies that pair antidepressants with FDA approved AD drugs. Preclinical studies also demonstrate a favorable effect of natural antidepressants for AD patients. Based on the preclinical studies there are a number of plausible antidepressants effects that may modulate the progression of AD. These effects include an increase in neurogenesis, improvement in learning and memory, elevation in the levels of neurotrophic factors and pCREB and a reduction of amyloid peptide burden. Based on this preclinical and clinical evidence, antidepressants represent a rational complimentary strategy for the treatment of AD patients with depression comorbidity.
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Affiliation(s)
- Marwa Aboukhatwa
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N Pine St, Baltimore, MD 21201, USA.
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1925
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Gerretsen P, Müller DJ, Tiwari A, Mamo D, Pollock BG. The intersection of pharmacology, imaging, and genetics in the development of personalized medicine. DIALOGUES IN CLINICAL NEUROSCIENCE 2010. [PMID: 20135894 PMCID: PMC3181934 DOI: 10.31887/dcns.2009.11.4/pgerretsen] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We currently rely on large randomized trials and meta-analyses to make clinical decisions; this places us at a risk of discarding subgroup or individually specific treatment options owing to their failure to prove efficacious across entire populations. There is a new era emerging in personalized medicine that will focus on individual differences that are not evident phenomenologically. Much research is directed towards identifying genes, endophenotypes, and biomarkers of disease that will facilitate diagnosis and predict treatment outcome. We are at the threshold of being able to predict treatment response, primarily through genetics and neuroimaging. In this review we discuss the most promising markers of treatment response and adverse effects emerging from the areas of pharmacogenetics and neuroimaging in depression and schizophrenia.
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Affiliation(s)
- Philip Gerretsen
- Centre for Addiction and Mental Health, University of Toronto, Canada
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1926
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Dagyte G, Trentani A, Postema F, Luiten PG, Den Boer JA, Gabriel C, Mocaër E, Meerlo P, Van der Zee EA. The novel antidepressant agomelatine normalizes hippocampal neuronal activity and promotes neurogenesis in chronically stressed rats. CNS Neurosci Ther 2010; 16:195-207. [PMID: 20236141 DOI: 10.1111/j.1755-5949.2009.00125.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Agomelatine is a novel antidepressant which acts as a melatonergic (MT1/MT2) receptor agonist and serotonergic (5-HT2C) receptor antagonist. The antidepressant properties of agomelatine have been demonstrated in animal models as well as in clinical studies. Several preclinical studies reported agomelatine-induced effects on brain plasticity, mainly under basal conditions in healthy animals. Yet, it is important to unravel agomelatine-mediated changes in the brain affected by psychopathology or exposed to conditions that might predispose to mood disorders. Since stress is implicated in the etiology of depression, it is valid to investigate antidepressant-induced effects in animals subjected to chronic stress. In this context, we sought to determine changes in the brain after agomelatine treatment in chronically stressed rats. Adult male rats were subjected to footshock stress and agomelatine treatment for 21 consecutive days. Rats exposed to footshock showed a robust increase in adrenocorticotropic hormone (ACTH) and corticosterone. Chronic agomelatine treatment did not markedly influence this HPA-axis response. Whereas chronic exposure to daily footshock stress reduced c-Fos expression in the hippocampal dentate gyrus, agomelatine treatment reversed this effect and normalized neuronal activity to basal levels. Moreover, chronic agomelatine administration was associated with enhanced hippocampal cell proliferation and survival in stressed but not in control rats. Furthermore, agomelatine reversed the stress-induced decrease in doublecortin expression in the dentate gyrus. Taken together, these data show a beneficial action of agomelatine in the stress-compromised brain, where it restores stress-affected hippocampal neuronal activity and promotes adult hippocampal neurogenesis.
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Affiliation(s)
- Girstaute Dagyte
- Department of Molecular Neurobiology, University of Groningen, The Netherlands.
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1927
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Colaianna M, Tucci P, Zotti M, Morgese MG, Schiavone S, Govoni S, Cuomo V, Trabace L. Soluble beta amyloid(1-42): a critical player in producing behavioural and biochemical changes evoking depressive-related state? Br J Pharmacol 2010; 159:1704-15. [PMID: 20218978 DOI: 10.1111/j.1476-5381.2010.00669.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND AND PURPOSE Depression is common in early phases of Alzheimer's disease (AD) and may represent prodromal symptoms of dementia. Recent reports suggest that early memory deficits and neuropsychiatric symptoms are caused by soluble rather than aggregated betaamyloid (Abeta). Thus, we investigated the effects of soluble Abeta(1-42) on working memory and depressive/anxiety-related behaviour in rats and on 5-hydroxytryptaminergic neurotransmission and neurotrophin content in various brain regions. EXPERIMENTAL APPROACH Behavioural reactivity to novel object recognition, open field, elevated plus maze and forced swimming test were assessed 7 days after i.c.v. injection of Abeta(1-42) or its vehicle. BDNF (brain-derived neurotrophic factor) and NGF (nerve growth factor) mRNA and protein levels and 5-hydroxytriptamine (5-HT) content were measured in the prefrontal cortex (PFC), striatum (STR) and nucleus accumbens (NAc). KEY RESULTS Abeta(1-42) did not affect the ability to distinguish between familiar and novel objects, but Abeta-treated rats exhibited an increase in forced swimming immobility. No differences were revealed between experimental groups in the elevated plus maze test or in self-grooming (evaluated in the open field). In the PFC, but not STR or NAc, Abeta-injected rats exhibited a selective reduction in 5-HT content, BDNF and NGF expression. CONCLUSIONS AND IMPLICATIONS Our data suggest that soluble Abeta-treated rats have a depressive, but not anxiogenic-like, profile, accompanied by brain region-dependent alterations in the expression of neurotrophins and 5-hydroxytryptaminergic neurotransmission. Hence, these alterations induced by soluble Abeta might be sensitive indicators of early phases of AD and possible risk factors for the expression of neuropsychiatric symptoms in AD.
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Affiliation(s)
- M Colaianna
- Department of Biomedical Sciences, University of Foggia, Italy
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1928
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Abstract
Negative cognitive bias-the tendency to interpret ambiguous situations pessimistically-is a central feature of stress-related disorders such as depression. The underlying neurobiology of this bias, however, remains unclear, not least because of a lack of translational tools. We established a new ambiguous-cue interpretation paradigm and, with respect to the etiology of depression, evaluated if environmental and genetic factors contribute to a negative bias. Rats were trained to press a lever to receive a food reward contingent to one tone and to press another lever in response to a different tone to avoid punishment by electric foot-shock. In the ambiguous-cue test, the lever-press responses to tones with frequencies intermediate to the trained tones were taken as indicators for the rats' expectation of a positive or negative event. A negative response bias because of decreased positive and increased negative responding was found in congenitally helpless rats, a genetic animal model of depression. Moreover, treatment with a combined noradrenergic-glucocorticoid challenge, mimicking stress-related changes in endogenous neuromodulation, biased rats away from positive responding. This response shift was accompanied by neuronal activation in dentate gyrus and amygdala. Thus, environmental and genetic risk factors for depression induce a response bias, which resembles the pessimistic bias of patients suffering from depression. The behavioral paradigm described constitutes a useful tool to study the neuronal basis of decision making under ambiguous conditions and may promote innovative pharmaco- and psychotherapy for depression.
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1929
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Abstract
Efforts to unlock the biology of major depressive disorder (MDD) are proceeding on multiple fronts. In this article, the authors review the current understanding of epidemiological evidence for a heritable component to MDD risk, as well as recent advances in linkage, candidate gene, and genome-wide association analyses of MDD and related disease subtypes and endophenotypes. While monoamine signaling has preoccupied the bulk of scientific investigation to date, nontraditional gene candidates such as PCLO and GRM7 are now emerging and beginning to change the landscape for future human and animal research on depression.
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Affiliation(s)
- Stanley I. Shyn
- Research fellow, Department of Psychiatry, Langley Porter Psychiatric Institute, University of California, San Francisco, San Francisco, CA
| | - Steven P. Hamilton
- Associate professor, Department of Psychiatry, Langley Porter Psychiatric Institute, University of California, San Francisco, San Francisco, CA,Corresponding author for proof & reprints: Steven P. Hamilton, MD-PhD, Carol Cochran Schaffner Endowed Chair, In Mental Health, Box 0984 - NGL, 401 Parnassus Ave, San Francisco, CA 94143-0984, Ph 415.476.7889, FAX 415.476.7800,
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1930
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Alpha2-adrenoceptor blockade accelerates the neurogenic, neurotrophic, and behavioral effects of chronic antidepressant treatment. J Neurosci 2010; 30:1096-109. [PMID: 20089918 DOI: 10.1523/jneurosci.2309-09.2010] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Slow-onset adaptive changes that arise from sustained antidepressant treatment, such as enhanced adult hippocampal neurogenesis and increased trophic factor expression, play a key role in the behavioral effects of antidepressants. alpha(2)-Adrenoceptors contribute to the modulation of mood and are potential targets for the development of faster acting antidepressants. We investigated the influence of alpha(2)-adrenoceptors on adult hippocampal neurogenesis. Our results indicate that alpha(2)-adrenoceptor agonists, clonidine and guanabenz, decrease adult hippocampal neurogenesis through a selective effect on the proliferation, but not the survival or differentiation, of progenitors. These effects persist in dopamine beta-hydroxylase knock-out (Dbh(-/-)) mice lacking norepinephrine, supporting a role for alpha(2)-heteroceptors on progenitor cells, rather than alpha(2)-autoreceptors on noradrenergic neurons that inhibit norepinephrine release. Adult hippocampal progenitors in vitro express all the alpha(2)-adrenoceptor subtypes, and decreased neurosphere frequency and BrdU incorporation indicate direct effects of alpha(2)-adrenoceptor stimulation on progenitors. Furthermore, coadministration of the alpha(2)-adrenoceptor antagonist yohimbine with the antidepressant imipramine significantly accelerates effects on hippocampal progenitor proliferation, the morphological maturation of newborn neurons, and the increase in expression of brain derived neurotrophic factor and vascular endothelial growth factor implicated in the neurogenic and behavioral effects of antidepressants. Finally, short-duration (7 d) yohimbine and imipramine treatment results in robust behavioral responses in the novelty suppressed feeding test, which normally requires 3 weeks of treatment with classical antidepressants. Our results demonstrate that alpha(2)-adrenoceptors, expressed by progenitor cells, decrease adult hippocampal neurogenesis, while their blockade speeds up antidepressant action, highlighting their importance as targets for faster acting antidepressants.
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1931
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Vizi ES, Fekete A, Karoly R, Mike A. Non-synaptic receptors and transporters involved in brain functions and targets of drug treatment. Br J Pharmacol 2010; 160:785-809. [PMID: 20136842 DOI: 10.1111/j.1476-5381.2009.00624.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Beyond direct synaptic communication, neurons are able to talk to each other without making synapses. They are able to send chemical messages by means of diffusion to target cells via the extracellular space, provided that the target neurons are equipped with high-affinity receptors. While synaptic transmission is responsible for the 'what' of brain function, the 'how' of brain function (mood, attention, level of arousal, general excitability, etc.) is mainly controlled non-synaptically using the extracellular space as communication channel. It is principally the 'how' that can be modulated by medicine. In this paper, we discuss different forms of non-synaptic transmission, localized spillover of synaptic transmitters, local presynaptic modulation and tonic influence of ambient transmitter levels on the activity of vast neuronal populations. We consider different aspects of non-synaptic transmission, such as synaptic-extrasynaptic receptor trafficking, neuron-glia communication and retrograde signalling. We review structural and functional aspects of non-synaptic transmission, including (i) anatomical arrangement of non-synaptic release sites, receptors and transporters, (ii) intravesicular, intra- and extracellular concentrations of neurotransmitters, as well as the spatiotemporal pattern of transmitter diffusion. We propose that an effective general strategy for efficient pharmacological intervention could include the identification of specific non-synaptic targets and the subsequent development of selective pharmacological tools to influence them.
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Affiliation(s)
- E S Vizi
- Department of Pharmacology, Institute of Experimental Medicine, Hungarian Academy of Sciences, Budapest, Hungary.
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1932
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Pan Y, Wang FM, Qiang LQ, Zhang DM, Kong LD. Icariin attenuates chronic mild stress-induced dysregulation of the LHPA stress circuit in rats. Psychoneuroendocrinology 2010; 35:272-83. [PMID: 19631474 DOI: 10.1016/j.psyneuen.2009.06.020] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 06/25/2009] [Accepted: 06/27/2009] [Indexed: 11/25/2022]
Abstract
Chronic mild stress (CMS) is suggested to develop dysregulation of the limbic-hypothalamic-pituitary-adrenal (LHPA) stress circuit. Icariin, a major constituent of flavonoids isolated from Epimedium brevicornum, has been previously confirmed to rescue the HPA axis abnormalities in animal models of depression. However, antidepressant treatment of icariin on corticotropin-releasing factor (CRF) system within the LHPA stress circuit and its interaction with serotonergic receptor are still seldom studied in CMS model of animals. The present study further investigated the effects of CMS procedure and subsequent icariin treatment on mRNA and protein levels of CRF, CRF receptor 1 (CRFR1) and CRF binding protein (CRFBP), as well as sucrose intake in rats. Moreover, the levels of cyclic adenosine 3',5'-monophosphate (cAMP) response element binding protein (CREB), glucocorticoid receptor (GR) and 5-hydroxytryptamine 1A receptor (5-HTR1A) in hypothalamus, hippocampus and frontal cortex were simultaneously evaluated for their participations in CRF system in this model. We found that CMS procedure significantly increased CRF expression levels in the brain regions, and decreased GR and 5-HTR1A in hippocampus and frontal cortex, with sucrose intake reduction representing the hedonic deficit in rats. Icariin restored these alterations in CMS rats. These results confirmed the hypothesis that icariin exerted antidepressant-like effect via its regulation of central CRF system. And hippocampus was suggested as an important neural area controlling the LHPA stress circuit in icariin-treated CMS rats. These findings for the first time proved that the potential molecular mechanism of antidepressant action of icariin was targeted on the interaction of the LHPA stress circuit and serotonergic function in CMS rats.
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Affiliation(s)
- Ying Pan
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, People's Republic of China
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1933
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Enkel T, Spanagel R, Vollmayr B, Schneider M. Stress triggers anhedonia in rats bred for learned helplessness. Behav Brain Res 2010; 209:183-6. [PMID: 20122969 DOI: 10.1016/j.bbr.2010.01.042] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Revised: 01/22/2010] [Accepted: 01/24/2010] [Indexed: 11/16/2022]
Abstract
Congenitally helpless (cLH) rats, a well-accepted model for depression, show reduced consumption of sweet solutions only under single-housing conditions, indicating anhedonia under stress. We investigated if anhedonic-like behaviour, measured by a reduction of sweetened-condensed milk (SCM) intake and the pleasure-attenuated startle response (PAS), could be induced by an electric foot-shock stress challenge in group-housed rats. After foot-shock stress, reduced SCM intake was observed in cLH rats compared to non-helpless (cNLH) rats. Furthermore, cLH rats also showed a decreased PAS, indicating deficient reward perception. In summary, we demonstrate that a predisposition for learned helplessness interacts with stress to trigger anhedonic-like behaviour in cLH rats. These findings further add to the validity of congenitally learned helplessness as an animal model of depression, since gene-environment interactions are considered to play a role in the etiology of this disorder.
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Affiliation(s)
- Thomas Enkel
- Dept. of Psychiatry and Psychotherapy, Central Institute of Mental Health, University of Heidelberg, 68159 Mannheim, Germany
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1934
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Peripheral brain-derived neurotrophic factor (BDNF) as a biomarker for affective disorders? Int J Neuropsychopharmacol 2010; 13:1-4. [PMID: 19995480 DOI: 10.1017/s1461145709991039] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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1935
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Liebenberg N, Wegener G, Harvey BH, Brink CB. Investigating the role of protein kinase-G in the antidepressant-like response of sildenafil in combination with muscarinic acetylcholine receptor antagonism. Behav Brain Res 2010; 209:137-41. [PMID: 20117144 DOI: 10.1016/j.bbr.2010.01.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 01/21/2010] [Accepted: 01/21/2010] [Indexed: 11/29/2022]
Abstract
The cGMP/PK-G pathway plays a crucial role in neuroprotection and neurotrophin support, and is possibly involved in antidepressant action. Recently we reported on a novel antidepressant-like response following simultaneous administration of sildenafil (phosphodiesterase 5 (PDE5) inhibitor, thereby increasing cGMP levels), and atropine (muscarinic acetylcholine receptor antagonist) in the rat forced swim test (FST). However, it is unclear whether the antidepressant-like activity of sildenafil+atropine is mediated via the activation of PK-G, an important down-stream effector for cGMP, and whether this may target known pathways in antidepressant action. We investigated whether the antidepressant-like response of sildenafil+/-atropine could be reversed by Rp-8-Br-PET-cGMP, a PK-G inhibitor, and also whether a combination of 8-Br-cGMP (PK-G activator)+/-atropine would likewise be active in the FST, and whether this combination could be attenuated by a PK-G inhibitor. 8-Br-cGMP alone, but not sildenafil alone, reduced immobility and selectively increased swimming in the FST. The antidepressant-like action of sildenafil was only evident following co-administration of atropine, and selectively increased climbing behaviour. Importantly, PK-G inhibition prevented the antidepressant-like effects of both 8-Br-cGMP and the sildenafil/atropine combination. These results confirm cholinergic-cGMP-PK-G interactions in the antidepressant-like effects of sildenafil, putatively acting via noradrenergic mechanisms, whereas direct PK-G activation induces antidepressant-like effects that are associated with enhancement of serotonergic neurotransmission.
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Affiliation(s)
- Nico Liebenberg
- School of Pharmacy, North-West University, Potchefstroom, South Africa
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1936
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Nuclear factor-kappaB is a critical mediator of stress-impaired neurogenesis and depressive behavior. Proc Natl Acad Sci U S A 2010; 107:2669-74. [PMID: 20133768 DOI: 10.1073/pnas.0910658107] [Citation(s) in RCA: 478] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Proinflammatory cytokines, such as IL-1beta, have been implicated in the cellular and behavioral effects of stress and in mood disorders, although the downstream signaling pathways underlying these effects have not been determined. In the present study, we demonstrate a critical role for NF-kappaB signaling in the actions of IL-1beta and stress. Stress inhibition of neurogenesis in the adult hippocampus, which has been implicated in the prodepressive effects of stress, is blocked by administration of an inhibitor of NF-kappaB. Further analysis reveals that stress activates NF-kappaB signaling and decreases proliferation of neural stem-like cells but not early neural progenitor cells in the adult hippocampus. We also find that depressive-like behaviors caused by exposure to chronic stress are mediated by NF-kappaB signaling. Together, these data identify NF-kappaB signaling as a critical mediator of the antineurogenic and behavioral actions of stress and suggest previously undescribed therapeutical targets for depression.
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1937
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Nucleus accumbens deep brain stimulation decreases ratings of depression and anxiety in treatment-resistant depression. Biol Psychiatry 2010; 67:110-6. [PMID: 19914605 DOI: 10.1016/j.biopsych.2009.09.013] [Citation(s) in RCA: 535] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Revised: 09/03/2009] [Accepted: 09/11/2009] [Indexed: 01/01/2023]
Abstract
BACKGROUND While most patients with depression respond to combinations of pharmacotherapy, psychotherapy, and electroconvulsive therapy (ECT), there are patients requiring other treatments. Deep brain stimulation (DBS) allows modulation of brain regions that are dysfunctional in depression. Since anhedonia is a feature of depression and there is evidence of dysfunction of the reward system, DBS to the nucleus accumbens (NAcc) might be promising. METHODS Ten patients suffering from very resistant forms of depression (treatment-resistant depression [TRD]), not responding to pharmacotherapy, psychotherapy, or ECT, were implanted with bilateral DBS electrodes in the NAcc. The mean (+/-SD) length of the current episode was 10.8 (+/-7.5) years; the number of past treatment courses was 20.8 (+/-8.4); and the mean Hamilton Depression Rating Scale (HDRS) was 32.5 (+/-5.3). RESULTS Twelve months following initiation of DBS treatment, five patients reached 50% reduction of the HDRS (responders, HDRS = 15.4 [+/-2.8]). The number of hedonic activities increased significantly. Interestingly, ratings of anxiety (Hamilton Anxiety Scale) were reduced in the whole group but more pronounced in the responders. The [18F]-2-fluoro-2-deoxy-D-glucose positron emission tomography data revealed that NAcc-DBS decreased metabolism in the subgenual cingulate and in prefrontal regions including orbital prefrontal cortex. A volume of interest analysis comparing responders and nonresponders identified metabolic decreases in the amygdala. CONCLUSIONS We demonstrate antidepressant and antianhedonic effects of DBS to NAcc in patients suffering from TRD. In contrast to other DBS depression studies, there was also an antianxiety effect. These effects are correlated with localized metabolic changes.
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1938
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Marchetti C, Tafi E, Middei S, Rubinacci MA, Restivo L, Ammassari-Teule M, Marie H. Synaptic adaptations of CA1 pyramidal neurons induced by a highly effective combinational antidepressant therapy. Biol Psychiatry 2010; 67:146-54. [PMID: 19892321 DOI: 10.1016/j.biopsych.2009.09.017] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 08/26/2009] [Accepted: 09/11/2009] [Indexed: 01/09/2023]
Abstract
BACKGROUND Antidepressants (AD) need to be chronically administered (weeks to months) to provide beneficial effects. Evidence suggests that combined administration of inhibitors of monoamine reuptake and phosphodiesterase type 4 allows a highly effective therapeutic action. Also, this coadministration more rapidly boosts the cyclic adenosine monophosphate (cAMP) pathway, which is normally activated during chronic treatment of single compounds. Little is known, however, about how this augmentation therapy affects the core mechanism of glutamatergic plasticity. We therefore investigated how in vivo combinational subchronic rolipram and imipramine (scRI) treatment affects depressive behavior, cAMP-dependent transcription, and glutamatergic transmission in the hippocampus, a region critically implicated in depression. METHODS Antidepressant properties of scRI were investigated through the forced swim test. Changes in cAMP-dependent transcription and synaptic transmission of CA1 pyramidal cells were explored with green fluorescent protein, enzyme-linked immunosorbent assay, electrophysiology recordings, and Golgi-Cox staining. RESULTS We demonstrate that scRI displays robust antidepressant properties compared with single-drug treatments and increases hippocampal c-Fos expression and brain-derived neurotrophic factor protein levels. These effects are accompanied by a specific increase in alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid and N-methyl-D-aspartate receptors in already existing synapses. Finally, both acute and subchronic treatments led to enhancement of long-term potentiation but differently affected spine density and morphology, with scRI administration specifically resulting in a large increase in stubby spines. CONCLUSIONS We conclude that scRI is highly effective in providing antidepressive effects, including the hippocampal transcriptional alterations normally observed with longer single-drug treatments. Furthermore, we identified scRI-induced modifications in glutamatergic transmission that probably underlie the beneficial action of this combinational therapy.
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1939
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Gersner R, Toth E, Isserles M, Zangen A. Site-specific antidepressant effects of repeated subconvulsive electrical stimulation: potential role of brain-derived neurotrophic factor. Biol Psychiatry 2010; 67:125-32. [PMID: 19880094 DOI: 10.1016/j.biopsych.2009.09.015] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 09/13/2009] [Accepted: 09/14/2009] [Indexed: 12/25/2022]
Abstract
BACKGROUND Electroconvulsive therapy (ECT) is a very effective treatment for major depression. This method involves robust nonfocal stimulation of the brain and can normalize both neurochemical alterations and depressive behavior in animal models. We hypothesized that short stimulation sessions of specific reward-related brain sites might induce similar effects. METHODS In the present study we compared behavioral and neurochemical effects produced by ECT and by repeated stimulation of reward-related brain sites, in a widely used rat model for depressive behavior induced by chronic mild stress (CMS). Different groups of rats received 10 sessions of either electroconvulsive shocks or subconvulsive electrical stimulation (SCES) of specific brain sites with an implanted electrode. The SCES temporal parameters were similar to those used in transcranial magnetic stimulation studies in humans. A battery of behavioral tests and measurements of brain-derived neurotrophic factor (BDNF) levels were used to assess the effectiveness of these treatments relative to sham treatments. RESULTS Repeated SCES of either the nucleus accumbens (NAC) or the ventral but not the dorsal prelimbic cortex (PLC) reversed the main behavioral deficit and the reduction of BDNF levels in the hippocampus that were induced by CMS. The ECT was more effective because it also normalized a behavioral deficit associated with anxiety but produced a learning and memory impairment. CONCLUSIONS This study implicates the ventral PLC and the NAC in the pathophysiology of depressive behavior and suggests that local intermittent SCES can induce an antidepressant effect similar to that of ECT, without the cognitive impairment caused by the convulsive treatment.
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Affiliation(s)
- Roman Gersner
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
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1940
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Abstract
Although there is an extensive amount known about specific sensory and motor functions of the vertebrate brain, less is understood about the regulation of global brain states. We have recently proposed that a function termed generalized arousal (Ag) serves as the most elemental driving force in the nervous system, responsible for the initial activation of all behavioral responses. An animal with increased generalized CNS arousal is characterized by greater motor activity, increased responsivity to sensory stimuli, and greater emotional lability. Implicit in this theory was the prediction that increases in generalized arousal would augment specific motivated behaviors that depend on arousal. Here, we address the idea directly by testing two lines of mice bred for high or low levels of generalized arousal and assessing their responses in tests of specific forms of behavioral arousal, sex and anxiety/exploration. We report that animals selected for differential generalized arousal exhibit marked increases in sensory, motor, and emotional reactivity in our arousal assay. Furthermore, male mice selected for high levels of generalized arousal were excitable and showed more incomplete mounts before the first intromission (IN), but having achieved that IN, they exhibited far fewer IN before ejaculating, as well as ejaculating much sooner after the first IN, thus indicating a high level of sexual arousal. Additionally, high-arousal animals of both sexes exhibited greater levels of anxiety-like behaviors and reduced exploratory behavior in the elevated plus maze and light-dark box tasks. Taken together, these data illustrate the impact of Ag on motivated behaviors.
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1941
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Brocco MA, Fernández ME, Frasch ACC. Filopodial protrusions induced by glycoprotein M6a exhibit high motility and aids synapse formation. Eur J Neurosci 2010; 31:195-202. [PMID: 20074218 DOI: 10.1111/j.1460-9568.2009.07064.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
M6a is a neuronal membrane glycoprotein whose expression diminishes during chronic stress. M6a overexpression in rat primary hippocampal neurons induces the formation of filopodial protrusions that could be spine precursors. As the filopodium and spine motility has been associated with synaptogenesis, we analysed the motility of M6a-induced protrusions by time-lapse imaging. Our data demonstrate that the motile protrusions formed by the neurons overexpressing M6a were more abundant and moved faster than those formed in control cells. When different putative M6a phosphorylation sites were mutated, the neurons transfected with a mutant lacking intracellular phosphorylation sites bore filopodia, but these protrusions did not move as fast as those formed by cells overexpressing wild-type M6a. This suggests a role for M6a phosphorylation state in filopodium motility. Furthermore, we show that M6a-induced protrusions could be stabilized upon contact with presynaptic region. The motility of filopodia contacting or not neurites overexpressing synaptophysin was analysed. We show that the protrusions that apparently contacted synaptophysin-labeled cells exhibited less motility. The behavior of filopodia from M6a-overexpressing cells and control cells was alike. Thus, M6a-induced protrusions may be spine precursors that move to reach presynaptic membrane. We suggest that M6a is a key molecule for spine formation during development.
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Affiliation(s)
- Marcela A Brocco
- Instituto de Investigaciones Biotecnológicas-Instituto Tecnológico de Chascomús-Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de General San Martín, Buenos Aires, Argentina.
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1942
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Childs E, Dlugos A, De Wit H. Cardiovascular, hormonal, and emotional responses to the TSST in relation to sex and menstrual cycle phase. Psychophysiology 2010; 47:550-9. [PMID: 20070572 DOI: 10.1111/j.1469-8986.2009.00961.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The prevalence of stress disorders differs between men and women. An understanding of how men and women vary in acute stress responses may help to understand these sex differences. We compared responses to the TSST and a control task in healthy men (N=28) and women tested in two phases (Follicular N=29, Luteal N=23) of the menstrual cycle. Men exhibited greater cortisol responses to stress than women in either phase. Luteal women exhibited the greatest subjective and allopregnanolone responses to stress, whereas follicular women exhibited blunted noradrenaline responses. Partial correlations controlling for group differences revealed that individuals who were most sensitive to the subjective effects of stress exhibited the largest salivary cortisol, noradrenaline, and allopregnanolone responses and the smallest progesterone responses to stress. We discuss our findings in the context of sex differences in the prevalence of stress-linked disorders.
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Affiliation(s)
- Emma Childs
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, Illinois 60637, USA.
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1943
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DeCarolis NA, Eisch AJ. Hippocampal neurogenesis as a target for the treatment of mental illness: a critical evaluation. Neuropharmacology 2010; 58:884-93. [PMID: 20060007 DOI: 10.1016/j.neuropharm.2009.12.013] [Citation(s) in RCA: 191] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2009] [Revised: 12/09/2009] [Accepted: 12/14/2009] [Indexed: 12/21/2022]
Abstract
Over one-quarter of adult Americans are diagnosed with a mental illness like Major Depressive Disorder (MDD), Post-Traumatic Stress Disorder (PTSD), schizophrenia, and Alzheimer's Disease. In addition to the exceptional personal burden these disorders exert on patients and their families, they also have enormous cost to society. Although existing pharmacological and psychosocial treatments alleviate symptoms in many patients, the comorbidity, severity, and intractable nature of mental disorders strongly underscore the need for novel strategies. As the hippocampus is a site of structural and functional pathology in most mental illnesses, a hippocampal-based treatment approach has been proposed to counteract the cognitive deficits and mood dysregulation that are hallmarks of psychiatric disorders. In particular, preclinical and clinical research suggests that hippocampal neurogenesis, the generation of new neurons in the adult dentate gyrus, may be harnessed to treat mental illness. There are obvious applications and allures of this approach; for example, perhaps stimulating hippocampal neurogenesis would reverse the overt and noncontroversial hippocampal atrophy and functional deficits observed in Alzheimer's Disease and schizophrenia, or the more controversial hippocampal deficits seen in MDD and PTSD. However, critical examination suggests that neurogenesis may only correlate with mental illness and treatment, suggesting targeting neurogenesis alone is not a sufficient treatment strategy. Here we review the classic and causative links between adult hippocampal neurogenesis and mental disorders, and provide a critical evaluation of how (and if) our basic knowledge of new neurons in the adult hippocampus might eventually help combat or even prevent mental illness.
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Affiliation(s)
- Nathan A DeCarolis
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX 75390-9070, USA
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1944
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Musazzi L, Milanese M, Farisello P, Zappettini S, Tardito D, Barbiero VS, Bonifacino T, Mallei A, Baldelli P, Racagni G, Raiteri M, Benfenati F, Bonanno G, Popoli M. Acute stress increases depolarization-evoked glutamate release in the rat prefrontal/frontal cortex: the dampening action of antidepressants. PLoS One 2010; 5:e8566. [PMID: 20052403 PMCID: PMC2797327 DOI: 10.1371/journal.pone.0008566] [Citation(s) in RCA: 190] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Accepted: 12/06/2009] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Behavioral stress is recognized as a main risk factor for neuropsychiatric diseases. Converging evidence suggested that acute stress is associated with increase of excitatory transmission in certain forebrain areas. Aim of this work was to investigate the mechanism whereby acute stress increases glutamate release, and if therapeutic drugs prevent the effect of stress on glutamate release. METHODOLOGY/FINDINGS Rats were chronically treated with vehicle or drugs employed for therapy of mood/anxiety disorders (fluoxetine, desipramine, venlafaxine, agomelatine) and then subjected to unpredictable footshock stress. Acute stress induced marked increase in depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex in superfusion, and the chronic drug treatments prevented the increase of glutamate release. Stress induced rapid increase in the circulating levels of corticosterone in all rats (both vehicle- and drug-treated), and glutamate release increase was blocked by previous administration of selective antagonist of glucocorticoid receptor (RU 486). On the molecular level, stress induced accumulation of presynaptic SNARE complexes in synaptic membranes (both in vehicle- and drug-treated rats). Patch-clamp recordings of pyramidal neurons in the prefrontal cortex revealed that stress increased glutamatergic transmission through both pre- and postsynaptic mechanisms, and that antidepressants may normalize it by reducing release probability. CONCLUSIONS/SIGNIFICANCE Acute footshock stress up-regulated depolarization-evoked release of glutamate from synaptosomes of prefrontal/frontal cortex. Stress-induced increase of glutamate release was dependent on stimulation of glucocorticoid receptor by corticosterone. Because all drugs employed did not block either elevation of corticosterone or accumulation of SNARE complexes, the dampening action of the drugs on glutamate release must be downstream of these processes. This novel effect of antidepressants on the response to stress, shown here for the first time, could be related to the therapeutic action of these drugs.
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Affiliation(s)
- Laura Musazzi
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
| | - Marco Milanese
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
| | - Pasqualina Farisello
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
- Department of Experimental Medicine, Section of Physiology, University of Genova and National Institute of Neuroscience, Genova, Italy
| | - Simona Zappettini
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
| | - Daniela Tardito
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
| | - Valentina S. Barbiero
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
| | - Tiziana Bonifacino
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
| | - Alessandra Mallei
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
| | - Pietro Baldelli
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
- Department of Experimental Medicine, Section of Physiology, University of Genova and National Institute of Neuroscience, Genova, Italy
| | - Giorgio Racagni
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
- Istituto di Ricovero e Cura a Carattere Scientifico San Giovanni di Dio - Fatebenefratelli, Brescia, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
- Department of Experimental Medicine, Section of Physiology, University of Genova and National Institute of Neuroscience, Genova, Italy
| | - Maurizio Raiteri
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
| | - Fabio Benfenati
- Department of Neuroscience and Brain Technologies, The Italian Institute of Technology, Genova, Italy
- Department of Experimental Medicine, Section of Physiology, University of Genova and National Institute of Neuroscience, Genova, Italy
| | - Giambattista Bonanno
- Department of Experimental Medicine, Section of Pharmacology and Toxicology, University of Genova, Genova, Italy
- Center of Excellence for Biomedical Research and National Institute of Neuroscience, Genova, Italy
| | - Maurizio Popoli
- Department of Pharmacological Sciences, Center of Neuropharmacology and Center of Excellence on Neurodegenerative Diseases, University of Milano, Milano, Italy
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1945
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Castrén E, Rantamäki T. Role of brain-derived neurotrophic factor in the aetiology of depression: implications for pharmacological treatment. CNS Drugs 2010; 24:1-7. [PMID: 20030415 DOI: 10.2165/11530010-000000000-00000] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) is a critical mediator of activity-dependent neuronal plasticity in the cerebral cortex. Deficits in neurotrophic factors have been proposed to underlie mood disorders. However, recent evidence suggests that mood disorders may be produced by abnormalities in the adaptation of neural networks to environmental conditions. Antidepressants may act by enhancing neuronal plasticity, which allows environmental inputs to modify the neuronal networks to better fine tune the individual to the outside world. Recent observations in the visual cortex directly support this idea. According to the network hypothesis of depression, changes in the levels of neurotrophins including BDNF may not directly produce depression or an antidepressant effect, but neurotrophins may act as critical tools in the process whereby environmental conditions guide neuronal networks to better adapt to the environment. This hypothesis suggests that antidepressant drugs should not be used alone but should always be combined with rehabilitation to guide the plastic networks within the brain.
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Affiliation(s)
- Eero Castrén
- Sigrid Jusélius Laboratory, Neuroscience Center, University of Helsinki, Helsinki, Finland.
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1946
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Segman RH, Goltser-Dubner T, Weiner I, Canetti L, Galili-Weisstub E, Milwidsky A, Pablov V, Friedman N, Hochner-Celnikier D. Blood mononuclear cell gene expression signature of postpartum depression. Mol Psychiatry 2010; 15:93-100, 2. [PMID: 19581911 DOI: 10.1038/mp.2009.65] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In sorrow thou shalt bring forth children (Genesis 3:16) seems as relevant today, with one of seven mothers afflicted by a depressive episode, constituting the most common medical complication after delivery. Why mothers are variably affected by mood symptoms postpartum remains unclear, and the pathogenesis and early molecular indicators of this divergent outcome have not been described. We applied a case-control design comparing differential global gene expression profiles in blood mononuclear cells sampled shortly after delivery at the time of inception of postpartum depression (PD). Nine antidepressant naive mothers showing high depressive scores and developing a persisting major depressive episode with postpartum onset were compared with 10 mothers showing low depressive scores and no depressive symptoms on prospective follow-up. A distinctive gene expression signature was observed after delivery among mothers with an emergent PD, with a significant overabundance of transcripts showing a high-fold differential expression between groups, and correlating with depressive symptom severity among all mothers. Early expression signatures correctly classified the majority of PD patients and controls. Those developing persisting PD exhibit a relative downregulation of transcription after delivery, with differential immune activation, and decreased transcriptional engagement in cell proliferation, and DNA replication and repair processes. Our data provide initial evidence indicating that blood cells sampled shortly after delivery may harbor valuable prognostic information for identifying the onset of persisting PD. Some of the informative transcripts and pathways may be implicated in the differential vulnerability that underlies depression pathogenesis.
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Affiliation(s)
- R H Segman
- Department of Psychiatry, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
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1947
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Covington HE, Vialou V, Nestler EJ. From synapse to nucleus: novel targets for treating depression. Neuropharmacology 2009; 58:683-93. [PMID: 20018197 DOI: 10.1016/j.neuropharm.2009.12.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Accepted: 12/07/2009] [Indexed: 12/28/2022]
Abstract
The need for newer compounds to treat depression is an ever-growing concern due to the enormous societal and financial ramifications of this disorder. Here, we review some of the candidate systems that could potentially be involved in depression, or an inherent resistance to depression termed resilience, and the numerous protein targets for these systems. A substantial body of literature provides strong evidence that neurotrophic factors, glutamate receptors, hypothalamic feeding peptides, nuclear hormone receptors, and epigenetic mechanisms, among others, will make for interesting targets when examining depressive behavior or resilience in preclinical models, and eventually clinical trials. Although some of these targets for depression already appear promising, new waves of more selective compounds for any molecular system should promote a better understanding of this complex disease and perhaps improved treatments.
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Affiliation(s)
- Herbert E Covington
- Fishberg Department of Neuroscience, Mount Sinai School of Medicine, NY 10029, USA
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1948
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Hauger RL, Risbrough V, Oakley RH, Olivares-Reyes JA, Dautzenberg FM. Role of CRF receptor signaling in stress vulnerability, anxiety, and depression. Ann N Y Acad Sci 2009; 1179:120-43. [PMID: 19906236 DOI: 10.1111/j.1749-6632.2009.05011.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Markers of hyperactive central corticotropin releasing factor (CRF) systems and CRF-related single nucleotide polymorphisms (SNPs) have been identified in patients with anxiety and depressive disorders. Designing more effective antagonists may now be guided by data showing that small molecules bind to transmembrane domains. Specifically, CRF(1) receptor antagonists have been developed as novel anxiolytic and antidepressant treatments. Because CRF(1) receptors become rapidly desensitized by G protein-coupled receptor kinase (GRK) and beta-arrestin mechanisms in the presence of high agonist concentrations, neuronal hypersecretion of synaptic CRF alone may be insufficient to account for excessive central CRF neurotransmission in stress-induced affective pathophysiology. In addition to desensitizing receptor function, GRK phosphorylation and beta-arrestin binding can shift a G protein-coupled receptor (GPCR) to signal selectively via the extracellular signal-regulated kinase/mitogen-activated protein kinase (ERK-MAPK) or Akt pathways independent of G proteins. Also, Epac-dependent CRF(1) receptor signaling via the ERK-MAPK pathway has been found to potentiate brain-derived neurotrophic factor (BDNF)-stimulated TrkB signaling. Thus, genetic or acquired abnormalities in GRK and beta-arrestin function may be involved in the pathophysiology of stress-induced anxiety and depression.
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Affiliation(s)
- Richard L Hauger
- Psychiatry Service, VA Healthcare System, University of California, San Diego, La Jolla, California, USA.
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1949
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Abstract
OBJECTIVE To serve as a conceptual map of the role of new interventions designed to reduce the burden of late-life depression. METHODS We identified three needs to be addressed by intervention research: (1) the need for novel interventions given that the existing treatments leave many older adults depressed and disabled; (2) the need for procedures enabling community-based agencies to offer interventions of known efficacy with fidelity; and (3) the need to increase access of depressed older adults to care. RESULTS Our model orders novel interventions according to their role in serving depressed older adults and according to their position in the efficacy, effectiveness, implementation, and dissemination testing continuum. We describe three interventions designed by our institute to exemplify intervention research at different level of the model. A common element is that each intervention personalizes care both at the level of the individuals served and the level of community agencies providing care. To this end, each intervention is designed to accommodate the strengths and limitations of both patients and agencies and introduces changes in the patients' environment and community agencies needed in order to assimilate the new intervention. CONCLUSIONS We suggest that this model provides conceptual guidance on how to shorten the testing cycle and bring urgently needed novel treatments and implementation approaches to the community. While replication studies are important, propose that most of the support should be directed to those projects that take rational risks, and after adequate preliminary evidence, make the next step along the testing continuum.
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Affiliation(s)
- George S Alexopoulos
- Weill Cornell Institute of Geriatric Psychiatry, Weill Cornell Medical College, 21 Bloomingdale Road, White Plains, NY, USA.
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1950
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Is subcortical-cortical midline activity in depression mediated by glutamate and GABA? A cross-species translational approach. Neurosci Biobehav Rev 2009; 34:592-605. [PMID: 19958790 DOI: 10.1016/j.neubiorev.2009.11.023] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 10/28/2009] [Accepted: 11/26/2009] [Indexed: 01/10/2023]
Abstract
Major depressive disorder has recently been characterized by abnormal resting state hyperactivity in anterior midline regions. The neurochemical mechanisms underlying resting state hyperactivity remain unclear. Since animal studies provide an opportunity to investigate subcortical regions and neurochemical mechanisms in more detail, we used a cross-species translational approach comparing a meta-analysis of human data to animal data on the functional anatomy and neurochemical modulation of resting state activity in depression. Animal and human data converged in showing resting state hyperactivity in various ventral midline regions. These were also characterized by abnormal concentrations of glutamate and gamma-aminobutyric acid (GABA) as well as by NMDA receptor up-regulation and AMPA and GABA receptor down-regulation. This cross-species translational investigation suggests that resting state hyperactivity in depression occurs in subcortical and cortical midline regions and is mediated by glutamate and GABA metabolism. This provides insight into the biochemical underpinnings of resting state activity in both depressed and healthy subjects.
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