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Surget A, Tanti A, Leonardo ED, Laugeray A, Rainer Q, Touma C, Palme R, Griebel G, Ibarguen-Vargas Y, Hen R, Belzung C. Antidepressants recruit new neurons to improve stress response regulation. Mol Psychiatry 2011; 16:1177-88. [PMID: 21537331 PMCID: PMC3223314 DOI: 10.1038/mp.2011.48] [Citation(s) in RCA: 359] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Recent research suggests an involvement of hippocampal neurogenesis in behavioral effects of antidepressants. However, the precise mechanisms through which newborn granule neurons might influence the antidepressant response remain elusive. Here, we demonstrate that unpredictable chronic mild stress in mice not only reduces hippocampal neurogenesis, but also dampens the relationship between hippocampus and the main stress hormone system, the hypothalamo-pituitary-adrenal (HPA) axis. Moreover, this relationship is restored by treatment with the antidepressant fluoxetine, in a neurogenesis-dependent manner. Specifically, chronic stress severely impairs HPA axis activity, the ability of hippocampus to modulate downstream brain areas involved in the stress response, the sensitivity of the hippocampal granule cell network to novelty/glucocorticoid effects and the hippocampus-dependent negative feedback of the HPA axis. Remarkably, we revealed that, although ablation of hippocampal neurogenesis alone does not impair HPA axis activity, the ability of fluoxetine to restore hippocampal regulation of the HPA axis under chronic stress conditions, occurs only in the presence of an intact neurogenic niche. These findings provide a mechanistic framework for understanding how adult-generated new neurons influence the response to antidepressants. We suggest that newly generated neurons may facilitate stress integration and that, during chronic stress or depression, enhancing neurogenesis enables a dysfunctional hippocampus to restore the central control on stress response systems, then allowing recovery.
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Affiliation(s)
- A Surget
- U930 Imaging and Brain, Inserm, Tours, France.
| | - A Tanti
- U930 Imaging and Brain, Inserm, Tours, France,Université François Rabelais, Tours, France
| | - E D Leonardo
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY, USA
| | - A Laugeray
- U930 Imaging and Brain, Inserm, Tours, France,Université François Rabelais, Tours, France
| | - Q Rainer
- U930 Imaging and Brain, Inserm, Tours, France,Université François Rabelais, Tours, France
| | - C Touma
- Research Group of Psychoneuroendocrinology, Max Planck Institute of Psychiatry, Munich, Germany
| | - R Palme
- Department of Biomedical Sciences/Biochemistry, University of Veterinary Medicine, Vienna, Austria
| | - G Griebel
- Exploratory Unit, Sanofi-Aventis, Chilly-Mazarin, France
| | - Y Ibarguen-Vargas
- U930 Imaging and Brain, Inserm, Tours, France,Université François Rabelais, Tours, France,Kavli Institute for Systems Neuroscience & Centre for the Biology of Memory, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - R Hen
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY, USA
| | - C Belzung
- U930 Imaging and Brain, Inserm, Tours, France,Université François Rabelais, Tours, France
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Sibille E, Su J, Leman S, Le Guisquet AM, Ibarguen-Vargas Y, Joeyen-Waldorf J, Glorioso C, Tseng GC, Pezzone M, Hen R, Belzung C. Lack of serotonin1B receptor expression leads to age-related motor dysfunction, early onset of brain molecular aging and reduced longevity. Mol Psychiatry 2007; 12:1042-56, 975. [PMID: 17420766 PMCID: PMC2515886 DOI: 10.1038/sj.mp.4001990] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Normal aging of the brain differs from pathological conditions and is associated with increased risk for psychiatric and neurological disorders. In addition to its role in the etiology and treatment of mood disorders, altered serotonin (5-HT) signaling is considered a contributing factor to aging; however, no causative role has been identified in aging. We hypothesized that a deregulation of the 5-HT system would reveal its contribution to age-related processes and investigated behavioral and molecular changes throughout adult life in mice lacking the regulatory presynaptic 5-HT(1B) receptor (5-HT(1B)R), a candidate gene for 5-HT-mediated age-related functions. We show that the lack of 5-HT(1B)R (Htr1b(KO) mice) induced an early age-related motor decline and resulted in decreased longevity. Analysis of life-long transcriptome changes revealed an early and global shift of the gene expression signature of aging in the brain of Htr1b(KO) mice. Moreover, molecular changes reached an apparent maximum effect at 18-months in Htr1b(KO) mice, corresponding to the onset of early death in that group. A comparative analysis with our previous characterization of aging in the human brain revealed a phylogenetic conservation of age-effect from mice to humans, and confirmed the early onset of molecular aging in Htr1b(KO) mice. Potential mechanisms appear independent of known central mechanisms (Bdnf, inflammation), but may include interactions with previously identified age-related systems (IGF-1, sirtuins). In summary, our findings suggest that the onset of age-related events can be influenced by altered 5-HT function, thus identifying 5-HT as a modulator of brain aging, and suggesting age-related consequences to chronic manipulation of 5-HT.
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Affiliation(s)
- E Sibille
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - J Su
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - S Leman
- EA3248 Psychobiologie des émotions, Faculté des Sciences et Techniques, Université François Rabelais, Tours, France
| | - AM Le Guisquet
- EA3248 Psychobiologie des émotions, Faculté des Sciences et Techniques, Université François Rabelais, Tours, France
| | - Y Ibarguen-Vargas
- EA3248 Psychobiologie des émotions, Faculté des Sciences et Techniques, Université François Rabelais, Tours, France
| | - J Joeyen-Waldorf
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA
| | - C Glorioso
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA
| | - GC Tseng
- Department of Biostatistics, University of Pittsburgh, Pittsburgh, PA, USA
| | - M Pezzone
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - R Hen
- Center for Neurobiology and Behavior, Columbia University, New York, NY, USA
| | - C Belzung
- EA3248 Psychobiologie des émotions, Faculté des Sciences et Techniques, Université François Rabelais, Tours, France
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