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Alshebib Y, Hori T, Goel A, Fauzi AA, Kashiwagi T. Adult human neurogenesis: A view from two schools of thought. IBRO Neurosci Rep 2023; 15:342-347. [PMID: 38025659 PMCID: PMC10665662 DOI: 10.1016/j.ibneur.2023.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/21/2023] [Accepted: 07/27/2023] [Indexed: 12/01/2023] Open
Abstract
Are we truly losing neurons as we grow older? If yes, why, and how can the lost neurons be replaced or compensated for? Is so-called adult neurogenesis (ANG) still a controversial process, particularly in the human cerebral cortex? How do adult-born neurons -if proven to exist- contribute to brain functions? Is adult neurogenesis a disease-relevant process, meaning that neural progenitor cells are dormant in adulthood, but they may be reactivated, for example, following stroke? Is the earnest hope to cure neurological diseases justifying the readiness to accept ANG claim uncritically? These are all fundamental issues that have not yet been firmly explained. Although it is completely understandable that some researchers believe that we can add new neurons to our inevitably deteriorating brain, the brain regeneration process still possesses intellectually and experimentally diverting views, as until now, there has been significant confusion about the concept of ANG. This paper is not intended to be an extensively analytical review distilling all findings and conclusions presented in the ANG literature. Instead, it is an attempt to discuss the commonly entertained opinions and then present our reflective insight concerning the current status quo of the field, which might help redirect research questions, avoid marketing an exaggerated hope, and more importantly, save the ever-limited resources, namely, intellectuals' time, facilities, and grants.
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Affiliation(s)
- Yasir Alshebib
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134–0088, Japan
| | - Tomokatsu Hori
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134–0088, Japan
| | - Atul Goel
- Department of Neurosurgery. K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai 400 012, Maharashtra, India
| | - Asra Al Fauzi
- Department of Neurosurgery, Faculty of Medicine Universitas Airlangga, Dr. Soetomo General Academic Hospital, Jl. Prof. Dr. Moestopo 6–8, Surabaya, Indonesia
| | - Taichi Kashiwagi
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
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Mendez-David I, David DJ, Deloménie C, Tritschler L, Beaulieu JM, Colle R, Corruble E, Gardier AM, Hen R. A complex relation between levels of adult hippocampal neurogenesis and expression of the immature neuron marker doublecortin. Hippocampus 2023; 33:1075-1093. [PMID: 37421207 DOI: 10.1002/hipo.23568] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 05/08/2023] [Accepted: 06/20/2023] [Indexed: 07/10/2023]
Abstract
We investigated the mechanisms underlying the effects of the antidepressant fluoxetine on behavior and adult hippocampal neurogenesis (AHN). After confirming our earlier report that the signaling molecule β-arrestin-2 (β-Arr2) is required for the antidepressant-like effects of fluoxetine, we found that the effects of fluoxetine on proliferation of neural progenitors and survival of adult-born granule cells are absent in the β-Arr2 knockout (KO) mice. To our surprise, fluoxetine induced a dramatic upregulation of the number of doublecortin (DCX)-expressing cells in the β-Arr2 KO mice, indicating that this marker can be increased even though AHN is not. We discovered two other conditions where a complex relationship occurs between the number of DCX-expressing cells compared to levels of AHN: a chronic antidepressant model where DCX is upregulated and an inflammation model where DCX is downregulated. We concluded that assessing the number of DCX-expressing cells alone to quantify levels of AHN can be complex and that caution should be applied when label retention techniques are unavailable.
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Affiliation(s)
- Indira Mendez-David
- Université Paris-Saclay, UVSQ, Centre de recherche en Epidémiologie et Santé des Populations (CESP), UMR 1018, CESP-Inserm, Team Moods, Faculté de Pharmacie, Bâtiment Henri MOISSAN, Orsay, France
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York, USA
| | - Denis Joseph David
- Université Paris-Saclay, UVSQ, Centre de recherche en Epidémiologie et Santé des Populations (CESP), UMR 1018, CESP-Inserm, Team Moods, Faculté de Pharmacie, Bâtiment Henri MOISSAN, Orsay, France
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York, USA
| | - Claudine Deloménie
- UMS-IPSIT ACTAGen, Inserm, CNRS, Ingénierie et Plateformes au Service de l'Innovation Thérapeutique, Université Paris-Saclay, Bâtiment Henri MOISSAN, Orsay, France
| | - Laurent Tritschler
- Université Paris-Saclay, UVSQ, Centre de recherche en Epidémiologie et Santé des Populations (CESP), UMR 1018, CESP-Inserm, Team Moods, Faculté de Pharmacie, Bâtiment Henri MOISSAN, Orsay, France
| | - Jean-Martin Beaulieu
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Romain Colle
- CESP, MOODS Team, INSERM UMR 1018, Faculté de Médecine, Univ Paris-Saclay, Le Kremlin Bicêtre, France
- Service Hospitalo-Universitaire de Psychiatrie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Le Kremlin Bicêtre, France
| | - Emmanuelle Corruble
- CESP, MOODS Team, INSERM UMR 1018, Faculté de Médecine, Univ Paris-Saclay, Le Kremlin Bicêtre, France
- Service Hospitalo-Universitaire de Psychiatrie de Bicêtre, Hôpitaux Universitaires Paris-Saclay, Assistance Publique-Hôpitaux de Paris, Hôpital de Bicêtre, Le Kremlin Bicêtre, France
| | - Alain Michel Gardier
- Université Paris-Saclay, UVSQ, Centre de recherche en Epidémiologie et Santé des Populations (CESP), UMR 1018, CESP-Inserm, Team Moods, Faculté de Pharmacie, Bâtiment Henri MOISSAN, Orsay, France
| | - René Hen
- Department of Psychiatry, Columbia University, New York, New York, USA
- Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York, USA
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Siopi E, Galerne M, Rivagorda M, Saha S, Moigneu C, Moriceau S, Bigot M, Oury F, Lledo PM. Gut microbiota changes require vagus nerve integrity to promote depressive-like behaviors in mice. Mol Psychiatry 2023; 28:3002-3012. [PMID: 37131071 PMCID: PMC10615761 DOI: 10.1038/s41380-023-02071-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 04/03/2023] [Accepted: 04/11/2023] [Indexed: 05/04/2023]
Abstract
Chronic stress constitutes a major risk factor for depression that can disrupt various aspects of homeostasis, including the gut microbiome (GM). We have recently shown that GM imbalance affects adult hippocampal (HPC) neurogenesis and induces depression-like behaviors, with the exact mechanisms being under active investigation. Here we hypothesized that the vagus nerve (VN), a key bidirectional route of communication between the gut and the brain, could relay the effects of stress-induced GM changes on HPC plasticity and behavior. We used fecal samples derived from mice that sustained unpredictable chronic mild stress (UCMS) to inoculate healthy mice and assess standard behavioral readouts for anxiety- and depressive-like behavior, conduct histological and molecular analyses for adult HPC neurogenesis and evaluate neurotransmission pathways and neuroinflammation. To study the potential role of the VN in mediating the effects of GM changes on brain functions and behavior, we used mice that sustained subdiaphragmatic vagotomy (Vx) prior the GM transfer. We found that inoculation of healthy mice with GM from UCMS mice activates the VN and induces early and sustained changes in both serotonin and dopamine neurotransmission pathways in the brainstem and HPC. These changes are associated with prompt and persistent deficits in adult HPC neurogenesis and induce early and sustained neuroinflammatory responses in the HPC. Remarkably, Vx abrogates adult HPC neurogenesis deficits, neuroinflammation and depressive-like behavior, suggesting that vagal afferent pathways are necessary to drive GM-mediated effects on the brain.
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Affiliation(s)
- Eleni Siopi
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Memory Unit, 75015, Paris, France.
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades-INEM, 75015, Paris, France.
| | - Mathieu Galerne
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades-INEM, 75015, Paris, France
| | - Manon Rivagorda
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades-INEM, 75015, Paris, France
| | - Soham Saha
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Memory Unit, 75015, Paris, France
| | - Carine Moigneu
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Memory Unit, 75015, Paris, France
| | - Stéphanie Moriceau
- Platform for Neurobehavior and Metabolism, Structure Fédérative de Recherche Necker, 26 INSERM US24/CNRS UAR 3633, 75015, Paris, France
| | - Mathilde Bigot
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Memory Unit, 75015, Paris, France
| | - Franck Oury
- Université Paris Cité, CNRS, INSERM, Institut Necker Enfants Malades-INEM, 75015, Paris, France
| | - Pierre-Marie Lledo
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Memory Unit, 75015, Paris, France.
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Weir N, Stevens B, Wagner S, Miles A, Ball G, Howard C, Chemmarappally J, McGinnity M, Hargreaves AJ, Tinsley C. Aligned Poly-l-lactic Acid Nanofibers Induce Self-Assembly of Primary Cortical Neurons into 3D Cell Clusters. ACS Biomater Sci Eng 2022; 8:765-776. [PMID: 35084839 DOI: 10.1021/acsbiomaterials.1c01102] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Relative to two-dimensional (2D) culture, three-dimensional (3D) culture of primary neurons has yielded increasingly physiological responses from cells. Electrospun nanofiber scaffolds are frequently used as a 3D biomaterial support for primary neurons in neural tissue engineering, while hydrophobic surfaces typically induce aggregation of cells. Poly-l-lactic acid (PLLA) was electrospun as aligned PLLA nanofiber scaffolds to generate a structure with both qualities. Primary cortical neurons from E18 Sprague-Dawley rats cultured on aligned PLLA nanofibers generated 3D clusters of cells that extended highly aligned, fasciculated neurite bundles within 10 days. These clusters were viable for 28 days and responsive to AMPA and GABA. Relative to the 2D culture, the 3D cultures exhibited a more developed profile; mass spectrometry demonstrated an upregulation of proteins involved in cortical lamination, polarization, and axon fasciculation and a downregulation of immature neuronal markers. The use of artificial neural network inference suggests that the increased formation of synapses may drive the increase in development that is observed for the 3D cell clusters. This research suggests that aligned PLLA nanofibers may be highly useful for generating advanced 3D cell cultures for high-throughput systems.
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Affiliation(s)
- Nick Weir
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Bob Stevens
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Sarah Wagner
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Amanda Miles
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Graham Ball
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Charlotte Howard
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Joseph Chemmarappally
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Martin McGinnity
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Alan Jeffrey Hargreaves
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
| | - Chris Tinsley
- School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, U.K
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Alshebib YA, Hori T, Kashiwagi T. HOP protein expression in the hippocampal dentate gyrus is acutely downregulated in a status epilepticus mouse model. IBRO Neurosci Rep 2021; 11:183-193. [PMID: 34766103 PMCID: PMC8569711 DOI: 10.1016/j.ibneur.2021.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 10/19/2021] [Indexed: 12/01/2022] Open
Abstract
Status epilepticus (SE) is a neurological emergency, and delayed management can lead to higher morbidity and mortality. It is thought that prolonged seizures stimulate stem cells in the hippocampus and that epileptogenesis may arise from aberrant connections formed by newly born cells, while others have suggested that the acute neuroinflammation and gliosis often seen in epileptic hippocampi contribute to hyperexcitability and epilepsy development. Previous studies have identified the expression of homeodomain-only protein (HOP) in the hippocampal dentate gyrus (HDG) and the heart. HOP was found to be a regulator of cell proliferation and differentiation during heart development, while it maintains the 'heart conduction system' in adulthood. However, little is known about HOP function in the adult HDG, particularly in the SE setting. Here, a HOP immunohistochemical profile in an SE mouse model was established. A total of 24 adult mice were analyzed 3-10 days following the SE episode, the 'acute phase'. Our findings demonstrate a significant downregulation of HOP and BLBP protein expression in the SE group following SE episodes, while HOP/Ki67 coexpression did not remarkably differ. Furthermore, coexpression of HOP/S100β and HOP/Prox1 was not observed, although we noticed insignificant HOP/DCX coexpression level. The findings of this study show no compelling evidence of proliferation, and newly added neurons were not identified during the acute phase following SE, although HOP protein expression was significantly decreased in the HDG. Similar to its counterpart in the adult heart, this suggests that HOP seems to play a key role in regulating signal conduction in adult hippocampus. Moreover, acute changes in HOP expression following SE could be part of an inflammatory response that could subsequently influence epileptogenicity.
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Key Words
- BLBP, Brain lipid-binding protein
- BrdU, 5-Bromo-2′-deoxyuridine
- Ctrl, control tissue
- DCX, Doublecortin
- EGFP, enhanced green fluorescent protein
- Epileptogenicity
- GCL, granule cell layer
- GFAP, Glial fibrillary acidic protein
- GFP, green fluorescent protein
- HDG, Hippocampal Dentate Gyrus
- HF, Hippocampus Formation
- HOP
- HOP, Homeodomain Only Protein
- Hippocampal Formation
- Homeodomain-Only Protein
- IHC, Immunohistochemistry
- NSC, Neural stem cells
- Neurocardiology
- Prox1, Prospero Homeobox 1
- RGL cell, Radial glia-like cell
- S100β, S100 calcium-binding protein B
- SE, Status Epilepticus
- SGZ, subgranular zone
- SVZ, subventricular zone
- Seizure-induced neuroinflammation
- Status Epileptics
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Affiliation(s)
- YA Alshebib
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134-0088, Japan
| | - Tomokatsu Hori
- Department of Neurosurgery, Tokyo Neurological Center Hospital, Tokyo 134-0088, Japan
| | - Taichi Kashiwagi
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
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Buyang Huanwu Decoction promotes neurogenesis via sirtuin 1/autophagy pathway in a cerebral ischemia model. Mol Med Rep 2021; 24:791. [PMID: 34515326 PMCID: PMC8441980 DOI: 10.3892/mmr.2021.12431] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 08/12/2021] [Indexed: 12/21/2022] Open
Abstract
Stroke is one of the main causes of disease-related mortality worldwide. Buyang Huanwu Decoction (BHD) has been used to protect against stroke and stroke-induced disability for several years in China. Studies have shown that BHD can relieve neuronal damage in rats with cerebral ischemia/reperfusion (I/R) injury. However, the mechanism remains unclear. A middle cerebral artery occlusion and reperfusion (MCAO-R) model was used in the present study. The animals were treated with BHD (5, 10 and 20 g/kg) or rapamycin. Infarct size and modified neurological severity score were calculated on day 5 following MCAO-R surgery. Cellular changes around the ischemic penumbra were revealed by hematoxylin and eosin and Nissl staining. The protein expression levels of nestin, brain-derived neurotrophic factor (BDNF), doublecortin on the X chromosome (DCX) and autophagy-related proteins (beclin 1, LC3-II and p62) in the peri-ischemic area of the brain were detected. The results demonstrated that post-surgical treatment with BHD reduced the brain infarct size and improved neurological deficits in MCAO-R rats. BHD protected against MCAO-R-induced neuronal impairment and promoted neurogenesis, increased the protein expression of nestin, BDNF and DCX and markedly enhanced autophagy by increasing beclin 1 and LC3-II and decreasing p62. Meanwhile, BHD promoted the expression of sirtuin 1 (SIRT1), an important regulator of autophagy. In conclusion, the present study suggested that post-surgical treatment with BHD could protect rat brains from I/R injury, potentially through the SIRT1/autophagy pathway.
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Liu RX, Ma J, Wang B, Tian T, Guo N, Liu SJ. No DCX-positive neurogenesis in the cerebral cortex of the adult primate. Neural Regen Res 2020; 15:1290-1299. [PMID: 31960815 PMCID: PMC7047795 DOI: 10.4103/1673-5374.272610] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Whether endogenous neurogenesis occurs in the adult cortex remains controversial. An increasing number of reports suggest that doublecortin (DCX)-positive neurogenesis persists in the adult primate cortex, attracting enormous attention worldwide. In this study, different DCX antibodies were used together with NeuN antibodies in immunohistochemistry and western blot assays using adjacent cortical sections from adult monkeys. Antibody adsorption, antigen binding, primary antibody omission and antibody-free experiments were used to assess specificity of the signals. We found either strong fluorescent signals, medium-weak intensity signals in some cells, weak signals in a few perikarya or near complete lack of labeling in adjacent cortical sections incubated with the various DCX antibodies. The putative DCX-positive cells in the cortex were also positive for NeuN, a specific marker of mature neurons. However, further experiments showed that most of these signals were either the result of antibody cross reactivity, the non-specificity of secondary antibodies or tissue autofluorescence. No confirmed DCX-positive cells were detected in the adult macaque cortex by immunofluorescence. Our findings show that DCX-positive neurogenesis does not occur in the cerebral cortex of adult primates, and that false-positive signals (artefacts) are caused by antibody cross reactivity and autofluorescence. The experimental protocols were approved by the Institutional Animal Care and Use Committee of the Institute of Neuroscience, Beijing, China (approval No. IACUC-AMMS-2014-501).
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Affiliation(s)
- Ruo-Xu Liu
- Institute of Military Cognition and Brain Sciences, Beijing, China
| | - Jie Ma
- Institute of Military Cognition and Brain Sciences, Beijing, China
| | - Bin Wang
- Institute of Military Cognition and Brain Sciences, Beijing, China
| | - Tian Tian
- Department of Pharmacy, Medical College, Huanghe S&T University, Zhengzhou, Henan Province, China
| | - Ning Guo
- Institute of Military Cognition and Brain Sciences, Beijing, China
| | - Shao-Jun Liu
- Institute of Military Cognition and Brain Sciences, Beijing, China
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Dhaliwal J, Kannangara TS, Vaculik M, Xue Y, Kumar KL, Maione A, Béïque JC, Shen J, Lagace DC. Adult hippocampal neurogenesis occurs in the absence of Presenilin 1 and Presenilin 2. Sci Rep 2018; 8:17931. [PMID: 30560948 PMCID: PMC6299003 DOI: 10.1038/s41598-018-36363-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 11/10/2018] [Indexed: 12/19/2022] Open
Abstract
Mutations in the presenilin genes (PS1 and PS2) are a major cause of familial-Alzheimer's disease (FAD). Presenilins regulate neurogenesis in the developing brain, with loss of PS1 inducing aberrant premature differentiation of neural progenitor cells, and additional loss of PS2 exacerbating this effect. It is unclear, however, whether presenilins are involved in adult neurogenesis, a process that may be impaired in Alzheimer's disease within the hippocampus. To investigate the requirement of presenilins in adult-generated dentate granule neurons, we examined adult neurogenesis in the PS2-/- adult brain and then employ a retroviral approach to ablate PS1 selectively in dividing progenitor cells of the PS2-/- adult brain. Surprisingly, the in vivo ablation of both presenilins resulted in no defects in the survival and differentiation of adult-generated neurons. There was also no change in the morphology or functional properties of the retroviral-labeled presenilin-null cells, as assessed by dendritic morphology and whole-cell electrophysiology analyses. Furthermore, while FACS analysis showed that stem and progenitor cells express presenilins, inactivation of presenilins from these cells, using a NestinCreERT2 inducible genetic approach, demonstrated no changes in the proliferation, survival, or differentiation of adult-generated cells. Therefore, unlike their significant role in neurogenesis during embryonic development, presenilins are not required for cell-intrinsic regulation of adult hippocampal neurogenesis.
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Affiliation(s)
- Jagroop Dhaliwal
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Timal S Kannangara
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Michael Vaculik
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Yingben Xue
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Keren L Kumar
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Amanda Maione
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Jean-Claude Béïque
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada
| | - Jie Shen
- Department of Neurology, Brigham and Women's Hospital and Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, 02115, USA
| | - Diane C Lagace
- Department of Cellular and Molecular Medicine, Brain and Mind Research Institute, and Neuroscience Program, University of Ottawa, Ottawa, Ontario, K1H8M5, Canada.
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Hueston CM, Cryan JF, Nolan YM. Stress and adolescent hippocampal neurogenesis: diet and exercise as cognitive modulators. Transl Psychiatry 2017; 7:e1081. [PMID: 28375209 PMCID: PMC5416690 DOI: 10.1038/tp.2017.48] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Revised: 01/04/2017] [Accepted: 02/01/2017] [Indexed: 02/08/2023] Open
Abstract
Adolescence is a critical period for brain maturation. Deciphering how disturbances to the central nervous system at this time affect structure, function and behavioural outputs is important to better understand any long-lasting effects. Hippocampal neurogenesis occurs during development and continues throughout life. In adulthood, integration of these new cells into the hippocampus is important for emotional behaviour, cognitive function and neural plasticity. During the adolescent period, maturation of the hippocampus and heightened levels of hippocampal neurogenesis are observed, making alterations to neurogenesis at this time particularly consequential. As stress negatively affects hippocampal neurogenesis, and adolescence is a particularly stressful time of life, it is important to investigate the impact of stressor exposure at this time on hippocampal neurogenesis and cognitive function. Adolescence may represent not only a time for which stress can have long-lasting effects, but is also a critical period during which interventions, such as exercise and diet, could ameliorate stress-induced changes to hippocampal function. In addition, intervention at this time may also promote life-long behavioural changes that would aid in fostering increased hippocampal neurogenesis and cognitive function. This review addresses both the acute and long-term stress-induced alterations to hippocampal neurogenesis and cognition during the adolescent period, as well as changes to the stress response and pubertal hormones at this time which may result in differential effects than are observed in adulthood. We hypothesise that adolescence may represent an optimal time for healthy lifestyle changes to have a positive and long-lasting impact on hippocampal neurogenesis, and to protect against stress-induced deficits. We conclude that future research into the mechanisms underlying the susceptibility of the adolescent hippocampus to stress, exercise and diet and the consequent effect on cognition may provide insight into why adolescence may be a vital period for correct conditioning of future hippocampal function.
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Affiliation(s)
- C M Hueston
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - J F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Y M Nolan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
- APC Microbiome Institute, University College Cork, Cork, Ireland
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Dioscin relieves endotoxemia induced acute neuro-inflammation and protect neurogenesis via improving 5-HT metabolism. Sci Rep 2017; 7:40035. [PMID: 28059131 PMCID: PMC5216397 DOI: 10.1038/srep40035] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 11/30/2016] [Indexed: 12/16/2022] Open
Abstract
Sepsis, in addition to causing fatality, is an independent risk factor for cognitive impairment among sepsis survivors. The pathologic mechanism of endotoxemia induced acute neuro-inflammation still has not been fully understood. For the first time, we found the disruption of neurotransmitters 5-HT, impaired neurogenesis and activation of astrocytes coupled with concomitant neuro-inflammation were the potential pathogenesis of endotoxemia induced acute neuro-inflammation in sepsis survivors. In addition, dioscin a natural steroidal saponin isolated from Chinese medicinal herbs, enhanced the serotonergic system and produced anti-depressant effect by enhancing 5-HT levels in hippocampus. What is more, this finding was verified by metabolic analyses of hippocampus, indicating 5-HT related metabolic pathway was involved in the pathogenesis of endotoxemia induced acute neuro-inflammation. Moreover, neuro-inflammation and neurogenesis within hippocampus were indexed using quantitative immunofluorescence analysis of GFAP DCX and Ki67, as well as real-time RT-PCR analysis of some gene expression levels in hippocampus. Our in vivo and in vitro studies show dioscin protects hippocampus from endotoxemia induced cascade neuro-inflammation through neurotransmitter 5-HT and HMGB-1/TLR4 signaling pathway, which accounts for the dioscin therapeutic effect in behavioral tests. Therefore, the current findings suggest that dioscin could be a potential approach for the therapy of endotoxemia induced acute neuro-inflammation.
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