1
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Sánchez-Varo R, López-Salas A, Beltran-Casanueva R, Díaz-Sánchez E, Alvarez-Contino JE, Barbancho-Fernández MA, Serrano-Castro P, Fuxe K, Borroto-Escuela DO, García-Casares N, Narváez M. Enhancement of neurogenesis and cognition through intranasal co-delivery of galanin receptor 2 (GALR2) and neuropeptide Y receptor 1 (NPY1R) agonists: a potential pharmacological strategy for cognitive dysfunctions. BEHAVIORAL AND BRAIN FUNCTIONS : BBF 2024; 20:6. [PMID: 38549164 PMCID: PMC10976774 DOI: 10.1186/s12993-024-00230-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 02/19/2024] [Indexed: 04/02/2024]
Abstract
BACKGROUND Spatial memory deficits and reduced neuronal survival contribute to cognitive decline seen in the aging process. Current treatments are limited, emphasizing the need for innovative therapeutic strategies. This research explored the combined effects of intranasally co-administered galanin receptor 2 (GALR2) and neuropeptide Y1 receptor (NPY1R) agonists, recognized for their neural benefits, on spatial memory, neuronal survival, and differentiation in adult rats. After intranasal co-delivery of the GALR2 agonist M1145 and a NPY1R agonist to adult rats, spatial memory was tested with the object-in-place task 3 weeks later. We examined neuronal survival and differentiation by assessing BrdU-IR profiles and doublecortin (DCX) labeled cells, respectively. We also used the GALR2 antagonist M871 to confirm GALR2's crucial role in promoting cell growth. RESULTS Co-administration improved spatial memory and increased the survival rate of mature neurons. The positive effect of GALR2 in cell proliferation was confirmed by the nullifying effects of its antagonist. The treatment boosted DCX-labeled newborn neurons and altered dendritic morphology, increasing cells with mature dendrites. CONCLUSIONS Our results show that intranasal co-delivery of GALR2 and NPY1R agonists improves spatial memory, boosts neuronal survival, and influences neuronal differentiation in adult rats. The significant role of GALR2 is emphasized, suggesting new potential therapeutic strategies for cognitive decline.
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Affiliation(s)
- Raquel Sánchez-Varo
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain
- Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), 28031, Madrid, Spain
| | - Alexander López-Salas
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Receptomics and Brain Disorders Lab, Universidad de Málaga. Facultad de Medicina., Edificio Lopez-Peñalver, Jimenez Fraud 10, 29071, Málaga, Spain
| | - Rasiel Beltran-Casanueva
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Universidad de Málaga. Facultad de Medicina., Edificio Lopez-Peñalver, Jimenez Fraud 10, 29071, Málaga, Spain
| | - Estela Díaz-Sánchez
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Vithas Málaga., Vithas Málaga. Grupo Hospitalario Vithas, Málaga, Spain
| | - Jose Erik Alvarez-Contino
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Receptomics and Brain Disorders Lab, Universidad de Málaga. Facultad de Medicina., Edificio Lopez-Peñalver, Jimenez Fraud 10, 29071, Málaga, Spain
| | - Miguel Angel Barbancho-Fernández
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain
| | - Pedro Serrano-Castro
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain
- Vithas Málaga., Vithas Málaga. Grupo Hospitalario Vithas, Málaga, Spain
- Instituto de Investigación Biomédica de Málaga, Unit of Neurology, Hospital Regional Universitario de Málaga, Málaga, Spain
| | - Kjell Fuxe
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Dasiel O Borroto-Escuela
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Receptomics and Brain Disorders Lab, Universidad de Málaga. Facultad de Medicina., Edificio Lopez-Peñalver, Jimenez Fraud 10, 29071, Málaga, Spain
| | - Natalia García-Casares
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain
- Departamento de Medicina y Dermatología. , Facultad de Medicina. Universidad de Málaga. , Málaga, Spain
| | - Manuel Narváez
- NeuronLab. Departamento Fisiología Humana, Histología Humana, Anatomía Patológica y Educación Física y Deportiva, Facultad de Medicina, Universidad de Malaga, 29071, Malaga, Spain.
- Instituto de Investigación Biomédica de Málaga-IBIMA-Plataforma Bionand, Universidad de Malaga, 29071, Malaga, Spain.
- Vithas Málaga., Vithas Málaga. Grupo Hospitalario Vithas, Málaga, Spain.
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2
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Iannucci J, Nizamutdinov D, Shapiro LA. Neurogenesis and chronic neurobehavioral outcomes are partially improved by vagus nerve stimulation in a mouse model of Gulf War Illness. Neurotoxicology 2022; 90:205-215. [DOI: 10.1016/j.neuro.2022.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/22/2022]
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3
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Santos VR, Melo IS, Pacheco ALD, Castro OWD. Life and death in the hippocampus: What's bad? Epilepsy Behav 2021; 121:106595. [PMID: 31759972 DOI: 10.1016/j.yebeh.2019.106595] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/30/2019] [Accepted: 10/01/2019] [Indexed: 01/13/2023]
Abstract
The hippocampal formation is crucial for the generation and regulation of several brain functions, including memory and learning processes; however, it is vulnerable to neurological disorders, such as epilepsy. Temporal lobe epilepsy (TLE), the most common type of epilepsy, changes the hippocampal circuitry and excitability, under the contribution of both neuronal degeneration and abnormal neurogenesis. Classically, neurodegeneration affects sensitive areas of the hippocampus, such as dentate gyrus (DG) hilus, as well as specific fields of the Ammon's horn, CA3, and CA1. In addition, the proliferation, migration, and abnormal integration of newly generated hippocampal granular cells (GCs) into the brain characterize TLE neurogenesis. Robust studies over the years have intensely discussed the effects of death and life in the hippocampus, though there are still questions to be answered about their possible benefits and risks. Here, we review the impacts of death and life in the hippocampus, discussing its influence on TLE, providing new perspectives or insights for the implementation of new possible therapeutic targets. This article is part of the Special Issue "NEWroscience 2018".
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Affiliation(s)
- Victor Rodrigues Santos
- Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil.
| | - Igor Santana Melo
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceio, Brazil
| | | | - Olagide Wagner de Castro
- Institute of Biological Sciences and Health, Federal University of Alagoas (UFAL), Maceio, Brazil.
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4
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Heppt J, Wittmann MT, Schäffner I, Billmann C, Zhang J, Vogt-Weisenhorn D, Prakash N, Wurst W, Taketo MM, Lie DC. β-catenin signaling modulates the tempo of dendritic growth of adult-born hippocampal neurons. EMBO J 2020; 39:e104472. [PMID: 32929771 PMCID: PMC7604596 DOI: 10.15252/embj.2020104472] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 01/07/2023] Open
Abstract
In adult hippocampal neurogenesis, stem/progenitor cells generate dentate granule neurons that contribute to hippocampal plasticity. The establishment of a morphologically defined dendritic arbor is central to the functional integration of adult‐born neurons. We investigated the role of canonical Wnt/β‐catenin signaling in dendritogenesis of adult‐born neurons. We show that canonical Wnt signaling follows a biphasic pattern, with high activity in stem/progenitor cells, attenuation in immature neurons, and reactivation during maturation, and demonstrate that this activity pattern is required for proper dendrite development. Increasing β‐catenin signaling in maturing neurons of young adult mice transiently accelerated dendritic growth, but eventually produced dendritic defects and excessive spine numbers. In middle‐aged mice, in which protracted dendrite and spine development were paralleled by lower canonical Wnt signaling activity, enhancement of β‐catenin signaling restored dendritic growth and spine formation to levels observed in young adult animals. Our data indicate that precise timing and strength of β‐catenin signaling are essential for the correct functional integration of adult‐born neurons and suggest Wnt/β‐catenin signaling as a pathway to ameliorate deficits in adult neurogenesis during aging.
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Affiliation(s)
- Jana Heppt
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Marie-Theres Wittmann
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.,Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Iris Schäffner
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Charlotte Billmann
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jingzhong Zhang
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Suzhou Institute of Biomedical Engineering and Technology (SIBET), Chinese Academy of Sciences, Suzhou, China
| | - Daniela Vogt-Weisenhorn
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Nilima Prakash
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Hamm-Lippstadt University of Applied Sciences, Hamm, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Makoto Mark Taketo
- Division of Experimental Therapeutics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Dieter Chichung Lie
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
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5
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Kerloch T, Clavreul S, Goron A, Abrous DN, Pacary E. Dentate Granule Neurons Generated During Perinatal Life Display Distinct Morphological Features Compared With Later-Born Neurons in the Mouse Hippocampus. Cereb Cortex 2020; 29:3527-3539. [PMID: 30215686 DOI: 10.1093/cercor/bhy224] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 08/06/2018] [Indexed: 02/07/2023] Open
Abstract
In nonhuman mammals and in particular in rodents, most granule neurons of the dentate gyrus (DG) are generated during development and yet little is known about their properties compared with adult-born neurons. Although it is generally admitted that these populations are morphologically indistinguishable once mature, a detailed analysis of developmentally born neurons is lacking. Here, we used in vivo electroporation to label dentate granule cells (DGCs) generated in mouse embryos (E14.5) or in neonates (P0) and followed their morphological development up to 6 months after birth. By comparison with mature retrovirus-labeled DGCs born at weaning (P21) or young adult (P84) stages, we provide the evidence that perinatally born neurons, especially embryonically born cells, are morphologically distinct from later-born neurons and are thus easily distinguishable. In addition, our data indicate that semilunar and hilar GCs, 2 populations in ectopic location, are generated during the embryonic and the neonatal periods, respectively. Thus, our findings provide new insights into the development of the different populations of GCs in the DG and open new questions regarding their function in the brain.
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Affiliation(s)
- Thomas Kerloch
- INSERM U1215, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Solène Clavreul
- INSERM U1215, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Adeline Goron
- INSERM U1215, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Djoher Nora Abrous
- INSERM U1215, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
| | - Emilie Pacary
- INSERM U1215, Neurocentre Magendie, Bordeaux, France.,Université de Bordeaux, Bordeaux, France
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6
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Luo L, Li C, Du X, Shi Q, Huang Q, Xu X, Wang Q. Effect of aerobic exercise on BDNF/proBDNF expression in the ischemic hippocampus and depression recovery of rats after stroke. Behav Brain Res 2019; 362:323-331. [DOI: 10.1016/j.bbr.2018.11.037] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/09/2018] [Accepted: 11/26/2018] [Indexed: 01/12/2023]
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7
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Abstract
Hippocampal abnormalities have been heavily implicated in the pathophysiology of schizophrenia. The dentate gyrus of the hippocampus was shown to manifest an immature molecular profile in schizophrenia subjects, as well as in various animal models of the disorder. In this position paper, we advance a hypothesis that this immature molecular profile is accompanied by an identifiable immature morphology of the dentate gyrus granule cell layer. We adduce evidence for arrested maturation of the dentate gyrus in the human schizophrenia-affected brain, as well as multiple rodent models of the disease. Implications of this neurohistopathological signature for current theory regarding the development of schizophrenia are discussed.
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Affiliation(s)
- Ayda Tavitian
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Wei Song
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
| | - Hyman M. Schipper
- Department of Neurology & Neurosurgery, Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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8
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Repositioning of Somatic Golgi Apparatus Is Essential for the Dendritic Establishment of Adult-Born Hippocampal Neurons. J Neurosci 2017; 38:631-647. [PMID: 29217690 DOI: 10.1523/jneurosci.1217-17.2017] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 10/02/2017] [Accepted: 10/29/2017] [Indexed: 01/22/2023] Open
Abstract
New dentate granule cells (DGCs) are continuously generated, and integrate into the preexisting hippocampal network in the adult brain. How an adult-born neuron with initially simple spindle-like morphology develops into a DGC, consisting of a single apical dendrite with further branches, remains largely unknown. Here, using retroviruses to birth date and manipulate newborn neurons, we examined initial dendritic formation and possible underlying mechanisms. We found that GFP-expressing newborn cells began to establish a DGC-like morphology at ∼7 d after birth, with a primary dendrite pointing to the molecular layer, but at this stage, with several neurites in the neurogenic zone. Interestingly, the Golgi apparatus, an essential organelle for neurite growth and maintenance, was dynamically repositioning in the soma of newborn cells during this initial integration stage. Two weeks after birth, by which time most neurites in the neurogenic zone were eliminated, a compact Golgi apparatus was positioned exclusively at the base of the primary dendrite. We analyzed the presence of Golgi-associated genes using single-cell transcriptomes of newborn DGCs, and among Golgi-related genes, found the presence of STK25 and STRAD, regulators of embryonic neuronal development. When we knocked down either of these two proteins, we found Golgi mislocalization and extensive aberrant dendrite formation. Furthermore, overexpression of a mutated form of STRAD, underlying the disorder polyhydramnios, megalencephaly, and symptomatic epilepsy, characterized by abnormal brain development and intractable epilepsy, caused similar defects in Golgi localization and dendrite formation in adult-born neurons. Together, our findings reveal a role for Golgi repositioning in regulating the initial integration of adult-born DGCs.SIGNIFICANCE STATEMENT Since the discovery of the continuous generation of new neurons in the adult hippocampus, extensive effort was directed toward understanding the functional contribution of these newborn neurons to the existing hippocampal circuit and associated behaviors, while the molecular mechanisms controlling their early morphological integration are less well understood. Dentate granule cells (DGCs) have a single, complex, apical dendrite. The events leading adult-born DGCs' to transition from simple spindle-like morphology to mature dendrite morphology are largely unknown. We studied establishment of newborn DGCs dendritic pattern and found it was mediated by a signaling pathway regulating precise localization of the Golgi apparatus. Furthermore, this Golgi-associated mechanism for dendrite establishment might be impaired in a human genetic epilepsy syndrome, polyhydramnios, megalencephaly, and symptomatic epilepsy.
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9
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Zhang X, Qu H, Wang Y, Zhao S, Xiao T, Zhao C, Teng W. Aberrant plasticity in the hippocampus after neonatal seizures. Int J Neurosci 2017; 128:384-391. [PMID: 28937832 DOI: 10.1080/00207454.2017.1384380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Xiaoqian Zhang
- Department of Neurology, The First Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Huiling Qu
- Department of Neurology, The People's Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Ying Wang
- Department of Neurology, The First Hospital of Dalian Medical University, Dalian, Liaoning, PR China
| | - Shanshan Zhao
- Department of Neurology, The First Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Ting Xiao
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning, PR China
- Key Laboratory of Immunodermatology, Ministry of Health, Ministry of Education, Shenyang, Liaoning, PR China
| | - Chuansheng Zhao
- Department of Neurology, The First Hospital of China Medical University, Shenyang, Liaoning, PR China
| | - Weiyu Teng
- Department of Neurology, The First Hospital of China Medical University, Shenyang, Liaoning, PR China
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10
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Late effect of developmental exposure to glycidol on hippocampal neurogenesis in mice: Loss of parvalbumin-expressing interneurons. ACTA ACUST UNITED AC 2017; 69:517-526. [PMID: 28495474 DOI: 10.1016/j.etp.2017.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 04/16/2017] [Indexed: 12/11/2022]
Abstract
Developmental exposure to glycidol of rats causes axonal injury targeting axon terminals in dams and transient disruption of late-stage differentiation of hippocampal neurogenesis, accompanying sustained increase in the number of reelin-producing or calretinin-expressing interneurons in offspring. The molecular mechanism of disruptive neurogenesis probably targets the newly generating nerve terminals. We previously found differences between mice and rats in the effects on hippocampal neurogenesis after developmental exposure to the same neurotoxic substances. In the present study, we examined the effects and underlying mechanisms of developmental exposure to glycidol on hippocampal neurogenesis in mice. Glycidol (800 or 1600ppm) was administered in drinking water to mated female mice from gestational day 6 to postnatal day 21. Compared to mice drinking water without glycidol (control), the exposed dams showed axon terminal injury at both concentrations of glycidol. The offspring of the dams that had received 1600ppm glycidol had fewer parvalbumin (PVALB)+ γ-aminobutyric acid (GABA)-ergic interneurons and neuron-specific nuclear protein+ postmitotic neurons in the hilus of the hippocampal dentate gyrus. Thus, exposure of glycidol to adult mice induced axonal degeneration equivalent to that seen in the rat; however, the target mechanism for the disruption of hippocampal neurogenesis by developmental exposure was different from that in rats, with the hilar neuronal population not affected until adulthood. Considering the role of PVALB+ GABAergic interneurons in the brain, developmental glycidol exposure in mice may cause a decline in cognitive function in later life, and involve a different mechanism from that targeting axon terminals in rats.
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11
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Friedman LK, Sharma A, Corcia M, Webster T, Qazi L, Simsovits D, Khalil Y, Hu S, Kantrowitz M, Hong H. Selective inhibition of metabotropic glutamate type 1 alpha receptor (mGluR1α) reduces cell proliferation and migration following status epilepticus in early development. Int J Dev Neurosci 2016; 54:6-21. [PMID: 27530811 DOI: 10.1016/j.ijdevneu.2016.08.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 08/09/2016] [Accepted: 08/11/2016] [Indexed: 12/16/2022] Open
Abstract
The present study examined whether a single or multiple episode(s) of status epilepticus induced with kainic acid (KA) during the first 3 weeks of postnatal (P) development would aberrantly stimulate proliferation zones that alters migration to potentially injured areas and whether they would be blocked by selective Group I mGluR antagonists. mGluR1α (LY367385) and mGluR5 (MPEP) antagonists were administered 2h following KA-induced status epilepticus and animals were examined after 7days. Proliferating cells of the subventricular zone (SVZ), third ventricle, hippocampus, amygdala cortical complex were analyzed with the proliferative marker, Ki67; and two complementary retrograde dye tracers. Proliferation increased in extrahippocampal limbic structures when KA was administered on P13 or P20 which correlated with number of injured cells at the older age. LY367385 post-treatment caused striking decreases in proliferation in all limbic structures in the presence and absence of injury, whereas a reduction with MPEP was observed only within the amygdala cortical complex (Amg/ERcx) in the presence of multiple seizures (3×KA). After 3×KA and LY367385 post-treatments, diminished co-staining of dye tracers with Ki67 was observed within the Amg/ERcx despite high levels of progenitors marked by the retrograde tracers in this region. This indicates that not only was local proliferation within the SVZ and distant structures inhibited, but also that migration itself was reduced indirectly since there were less cells to migrate from the SVZ. Co-labeling with biomarkers provided evidence for neuronal differentiation suggesting potential aberrant integration may occur in distant locations, and that targeting of mGluR1α receptors may be a potential therapeutic strategy for future development.
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Affiliation(s)
- L K Friedman
- New York Medical College, Valhalla, NY, United States; New York College of Osteopathic Medicine, Old Westbury, NY, United States.
| | - A Sharma
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - M Corcia
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - T Webster
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - L Qazi
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - D Simsovits
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - Y Khalil
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - S Hu
- New York Medical College, Valhalla, NY, United States
| | - M Kantrowitz
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
| | - H Hong
- New York College of Osteopathic Medicine, Old Westbury, NY, United States
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12
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Gros A, Veyrac A, Laroche S. [Brain and memory: new neurons to remember]. Biol Aujourdhui 2016; 209:229-248. [PMID: 26820830 DOI: 10.1051/jbio/2015028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Indexed: 06/05/2023]
Abstract
A defining characteristic of the brain is its remarkable capacity to undergo activity-dependent functional and structural remodelling via mechanisms of plasticity that form the basis of our capacity to encode and retain memories. The prevailing model of how our brain stores new information about relationships between events or new abstract constructs suggests it resides in activity-driven modifications of synaptic strength and remodelling of neural networks brought about by cellular and molecular changes within the neurons activated during learning. To date, the idea that a form of activity-dependent synaptic plasticity known as long-term potentiation, or LTP, and the associated synaptic growth play a central role in the laying down of memories has received considerable support. Beyond this mechanism of plasticity at the synapse, adult neurogenesis, i.e. the birth and growth of new neurons, is another form of neural plasticity that occurs continuously in defined brain regions such as the dentate gyrus of the hippocampus. Here, based on work in the hippocampus, we review the processes and mechanisms of the generation and selection of new neurons in the adult brain and the accumulating evidence that supports the idea that this form of neural plasticity is essential to store and lead to retrievable hippocampal-dependent memories.
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Affiliation(s)
- Alexandra Gros
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Alexandra Veyrac
- Centre de Recherche en Neurosciences de Lyon, UMR 5292 CNRS, INSERM U1028, Université Lyon 1, 69366 Lyon, France
| | - Serge Laroche
- Institut des Neurosciences Paris-Saclay, UMR 9197, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
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13
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Llorens-Martín M, Rábano A, Ávila J. The Ever-Changing Morphology of Hippocampal Granule Neurons in Physiology and Pathology. Front Neurosci 2016; 9:526. [PMID: 26834550 PMCID: PMC4717329 DOI: 10.3389/fnins.2015.00526] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/29/2015] [Indexed: 11/29/2022] Open
Abstract
Newborn neurons are continuously added to the hippocampal dentate gyrus throughout adulthood. In this review, we analyze the maturational stages that newborn granule neurons go through, with a focus on their unique morphological features during each stage under both physiological and pathological circumstances. In addition, the influence of deleterious (such as schizophrenia, stress, Alzheimer's disease, seizures, stroke, inflammation, dietary deficiencies, or the consumption of drugs of abuse or toxic substances) and neuroprotective (physical exercise and environmental enrichment) stimuli on the maturation of these cells will be examined. Finally, the regulation of this process by proteins involved in neurodegenerative and neurological disorders such as Glycogen synthase kinase 3β, Disrupted in Schizophrenia 1 (DISC-1), Glucocorticoid receptor, pro-inflammatory mediators, Presenilin-1, Amyloid precursor protein, Cyclin-dependent kinase 5 (CDK5), among others, will be evaluated. Given the recently acquired relevance of the dendritic branch as a functional synaptic unit required for memory storage, a full understanding of the morphological alterations observed in newborn neurons may have important consequences for the prevention and treatment of the cognitive and affective alterations that evolve in conjunction with impaired adult hippocampal neurogenesis.
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Affiliation(s)
- María Llorens-Martín
- Molecular Neurobiology, Function of Microtubular Proteins, Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid)Madrid, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (Instituto de Salud Carlos III)Madrid, Spain
| | - Alberto Rábano
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (Instituto de Salud Carlos III)Madrid, Spain; Neuropathology Department, CIEN FoundationMadrid, Spain
| | - Jesús Ávila
- Molecular Neurobiology, Function of Microtubular Proteins, Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid)Madrid, Spain; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (Instituto de Salud Carlos III)Madrid, Spain
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Akane H, Saito F, Shiraki A, Takeyoshi M, Imatanaka N, Itahashi M, Murakami T, Shibutani M. Downregulation of immediate-early genes linking to suppression of neuronal plasticity in rats after 28-day exposure to glycidol. Toxicol Appl Pharmacol 2014; 279:150-62. [DOI: 10.1016/j.taap.2014.05.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 05/05/2014] [Accepted: 05/28/2014] [Indexed: 11/26/2022]
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Akane H, Saito F, Shiraki A, Imatanaka N, Akahori Y, Itahashi M, Wang L, Shibutani M. Gene expression profile of brain regions reflecting aberrations in nervous system development targeting the process of neurite extension of rat offspring exposed developmentally to glycidol. J Appl Toxicol 2014; 34:1389-99. [DOI: 10.1002/jat.2971] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 11/07/2013] [Accepted: 11/07/2013] [Indexed: 01/09/2023]
Affiliation(s)
- Hirotoshi Akane
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; 3-5-8 Saiwai-cho, Fuchu-shi Tokyo 183-8509 Japan
| | - Fumiyo Saito
- Chemicals Evaluation and Research Institute; Japan, 1-4-25 Koraku, Bunkyo-ku Tokyo 112-0004 Japan
| | - Ayako Shiraki
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; 3-5-8 Saiwai-cho, Fuchu-shi Tokyo 183-8509 Japan
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences; Gifu University; 1-1 Yanagido, Gifu-shi Gifu 501-1193 Japan
| | - Nobuya Imatanaka
- Chemicals Evaluation and Research Institute; Japan, 1-4-25 Koraku, Bunkyo-ku Tokyo 112-0004 Japan
| | - Yumi Akahori
- Chemicals Evaluation and Research Institute; Japan, 1-4-25 Koraku, Bunkyo-ku Tokyo 112-0004 Japan
| | - Megu Itahashi
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; 3-5-8 Saiwai-cho, Fuchu-shi Tokyo 183-8509 Japan
- Pathogenetic Veterinary Science, United Graduate School of Veterinary Sciences; Gifu University; 1-1 Yanagido, Gifu-shi Gifu 501-1193 Japan
| | - Liyun Wang
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; 3-5-8 Saiwai-cho, Fuchu-shi Tokyo 183-8509 Japan
| | - Makoto Shibutani
- Laboratory of Veterinary Pathology; Tokyo University of Agriculture and Technology; 3-5-8 Saiwai-cho, Fuchu-shi Tokyo 183-8509 Japan
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Akane H, Shiraki A, Imatanaka N, Akahori Y, Itahashi M, Abe H, Shibutani M. Glycidol induces axonopathy and aberrations of hippocampal neurogenesis affecting late-stage differentiation by exposure to rats in a framework of 28-day toxicity study. Toxicol Lett 2014; 224:424-32. [DOI: 10.1016/j.toxlet.2013.10.026] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 10/22/2013] [Accepted: 10/23/2013] [Indexed: 11/30/2022]
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Lima M, Malheiros J, Negrigo A, Tescarollo F, Medeiros M, Suchecki D, Tannús A, Guinsburg R, Covolan L. Sex-related long-term behavioral and hippocampal cellular alterations after nociceptive stimulation throughout postnatal development in rats. Neuropharmacology 2013; 77:268-76. [PMID: 24148811 DOI: 10.1016/j.neuropharm.2013.10.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 10/03/2013] [Accepted: 10/06/2013] [Indexed: 01/21/2023]
Abstract
Early noxious stimuli may alter the neurogenesis rate in the dentate gyrus and the behavioral repertoire of adult rats. This study evaluated the long-term effects of noxious stimulation, imposed in different phases of development, on nociceptive and anxiety-like behaviors, hippocampal activation, cell proliferation, hippocampal BDNF and plasma corticosterone levels in 40 day-old male and female adolescents. Noxious stimulation was induced by intra-plantar injection of Complete Freund's adjuvant (CFA), on postnatal days (P) 1 (group P1), 8 (P8) or 21 (P21). Control animals were not stimulated in any way. On P21 a subset of animals from each group received BrdU and was perfused on P40 for identification of proliferating cells in the granule cell layer of the dentate gyrus. Another subset of rats was subjected to behavioral testing on P40 and one week later, to magnetic resonance imaging (MRI) acquisition. Noxious stimulation evoked hypoalgesia in adolescents, mainly in females (P < 0.02), reflected by greater latency to withdraw the paw and less paw lickings in the hot plate test than controls (P < 0.001). It also resulted in more time spent in the open arms, e.g., less anxiety-like behavior than controls (P < 0.01), especially in females (P < 0.01, compared with males). Proliferative cell rate in the dentate gyrus was the highest in P8 males and females (P < 0.001), with males exhibiting more proliferation than females on P1 and P8, which was directly related to the hippocampal levels of BDNF and inversely related to plasma corticosterone. Sex differences were also detected in manganese-enhanced MRI signal, which was more prominent in P1 females than males (P < 0.01). This study represents the first step of investigation on the cellular basis of the sex-dependent long-term consequences of nociceptive stimuli in newborns.
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Affiliation(s)
- Márcia Lima
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - Jackeline Malheiros
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil; Centro de Imagens e Espectroscopia in vivo por Ressonância Magnética (CIERMag), Instituto de Física de São Carlos, Universidade de São Paulo (IFSC-USP), São Carlos 13566-590, Brazil
| | - Aline Negrigo
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - Fabio Tescarollo
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil
| | - Magda Medeiros
- Departamento de Ciências Fisiológicas, Universidade Federal Rural do Rio de Janeiro, Seropédica 23890-000, Brazil
| | - Deborah Suchecki
- Departamento de Psicobiologia, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil
| | - Alberto Tannús
- Centro de Imagens e Espectroscopia in vivo por Ressonância Magnética (CIERMag), Instituto de Física de São Carlos, Universidade de São Paulo (IFSC-USP), São Carlos 13566-590, Brazil
| | - Ruth Guinsburg
- Disciplina de Pediatria Neonatal, Departamento de Pediatria, Universidade Federal de São Paulo, São Paulo 04023-062, Brazil
| | - Luciene Covolan
- Departamento de Fisiologia, Universidade Federal de São Paulo, São Paulo, SP 04023-062, Brazil.
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Akane H, Shiraki A, Imatanaka N, Akahori Y, Itahashi M, Ohishi T, Mitsumori K, Shibutani M. Glycidol Induces Axonopathy by Adult-Stage Exposure and Aberration of Hippocampal Neurogenesis Affecting Late-Stage Differentiation by Developmental Exposure in Rats. Toxicol Sci 2013; 134:140-54. [DOI: 10.1093/toxsci/kft092] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shin MS, Ko IG, Kim SE, Kim BK, Kim TS, Lee SH, Hwang DS, Kim CJ, Park JK, Lim BV. Treadmill exercise ameliorates symptoms of methimazole-induced hypothyroidism through enhancing neurogenesis and suppressing apoptosis in the hippocampus of rat pups. Int J Dev Neurosci 2013; 31:214-23. [PMID: 23328696 DOI: 10.1016/j.ijdevneu.2013.01.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Revised: 01/02/2013] [Accepted: 01/07/2013] [Indexed: 12/14/2022] Open
Abstract
Thyroid hormones play a crucial role in new neuron production and maturation during brain development. Physical exercise is known to promote cell survival and functional recovery after brain injuries. In the present study, we investigated the effects of treadmill exercise on short-term memory, spatial learning ability, neurogenesis, and apoptosis in hypothyroidism rat pups. On the 14th perinatal day, the pregnant rats were divided into two groups: the maternal control group and the maternal methimazole (MMI)-treated group. For the induction of hypothyroidism in rat pups, MMI was added to the drinking water (0.02%, wt/vol), from the 14th prenatal day to the 49th postnatal day. After delivery, the male rat pups born from the maternal control group were assigned into the control group and the control and exercise group. The rat pups born from the maternal MMI-treated group were divided into the hypothyroidism-induction group and the hypothyroidism-induction and treadmill exercise group. The rat pups in the exercise groups were forced to run on a motorized treadmill for 30min once a day, starting on the 22nd postnatal day for 4 weeks. Induction of hypothyroidism during the fetal and early postnatal period showed suppression of neurogenesis and enhancement of apoptosis in the hippocampus. Short-term memory and spatial learning ability were deteriorated in the hypothyroidism rat pups. Treadmill exercise during the postnatal period increased neurogenesis and inhibited apoptosis, and resulted in the improvement of short-term memory and spatial learning ability in the hypothyroidism rat pups.
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Affiliation(s)
- Mal-Soon Shin
- Department of Physiology, College of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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Schoenfeld TJ, Gould E. Differential effects of stress and glucocorticoids on adult neurogenesis. Curr Top Behav Neurosci 2013; 15:139-164. [PMID: 23670817 DOI: 10.1007/7854_2012_233] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Stress is known to inhibit neuronal growth in the hippocampus. In addition to reducing the size and complexity of the dendritic tree, stress and elevated glucocorticoid levels are known to inhibit adult neurogenesis. Despite the negative effects of stress hormones on progenitor cell proliferation in the hippocampus, some experiences which produce robust increases in glucocorticoid levels actually promote neuronal growth. These experiences, including running, mating, enriched environment living, and intracranial self-stimulation, all share in common a strong hedonic component. Taken together, the findings suggest that rewarding experiences buffer progenitor cells in the dentate gyrus from the negative effects of elevated stress hormones. This chapter considers the evidence that stress and glucocorticoids inhibit neuronal growth along with the paradoxical findings of enhanced neuronal growth under rewarding conditions with a view toward understanding the underlying biological mechanisms.
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Affiliation(s)
- Timothy J Schoenfeld
- Department of Psychology, Neuroscience Institute, Princeton University, Princeton, NJ, 08545, USA
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Ohishi T, Wang L, Akane H, Shiraki A, Goto K, Ikarashi Y, Suzuki K, Mitsumori K, Shibutani M. Reversible aberration of neurogenesis affecting late-stage differentiation in the hippocampal dentate gyrus of rat offspring after maternal exposure to manganese chloride. Reprod Toxicol 2012; 34:408-19. [DOI: 10.1016/j.reprotox.2012.04.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Revised: 03/15/2012] [Accepted: 04/25/2012] [Indexed: 01/13/2023]
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Wang L, Ohishi T, Shiraki A, Morita R, Akane H, Ikarashi Y, Mitsumori K, Shibutani M. Developmental exposure to manganese chloride induces sustained aberration of neurogenesis in the hippocampal dentate gyrus of mice. Toxicol Sci 2012; 127:508-21. [PMID: 22407947 DOI: 10.1093/toxsci/kfs110] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
The effect of exogenously administered manganese (Mn) on developmental neurogenesis in the hippocampal dentate gyrus was examined in male mice after maternal exposure to MnCl(2) (0, 32, 160, or 800 ppm as Mn in diet) from gestational day 10 to day 21 after delivery on weaning. Immunohistochemistry was performed to monitor neurogenesis and interneuron subpopulations on postnatal days (PNDs) 21 and 77 (adult stage). Reelin-synthesizing γ-aminobutyric acid (GABA)ergic interneurons increased in the hilus with ≥ 160 ppm on weaning to sustain to PND 77 at 800 ppm. Apoptosis in the neuroblast-producing subgranular zone increased with 800 ppm and TUC4-expressing immature granule cells decreased with 800 ppm on weaning, whereas at the adult stage, immature granule cells increased. On PND 21, transcript levels increased with Reln and its receptor gene Lrp8 and decreased with Dpysl3 coding TUC4 in the dentate gyrus, confirming immunohistochemical results. Double immunohistochemistry revealed a sustained increase of reelin-expressing and NeuN-lacking or weakly positive immature interneurons and NeuN-expressing mature neurons in the hilus through to the adult stage as examined at 800 ppm. Brain Mn concentrations increased at both PNDs 21 and 77 in all MnCl(2)-exposed groups. These results suggest that Mn targets immature granule cells causing apoptosis and neuronal mismigration. Sustained increases in immature reelin-synthesizing GABAergic interneurons may represent continued aberration in neurogenesis and following migration to cause an excessive response for overproduction of immature granule cells through to the adult stage. Sustained high concentration of Mn in the brain may be responsible for these changes.
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Affiliation(s)
- Liyun Wang
- Laboratory of Veterinary Pathology, Tokyo University of Agriculture and Technology, Fuchu-shi, Tokyo 183-8509, Japan
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Bonfanti L, Nacher J. New scenarios for neuronal structural plasticity in non-neurogenic brain parenchyma: the case of cortical layer II immature neurons. Prog Neurobiol 2012; 98:1-15. [PMID: 22609484 DOI: 10.1016/j.pneurobio.2012.05.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 04/25/2012] [Accepted: 05/08/2012] [Indexed: 11/20/2022]
Abstract
The mammalian central nervous system, due to its interaction with the environment, must be endowed with plasticity. Conversely, the nervous tissue must be substantially static to ensure connectional invariability. Structural plasticity can be viewed as a compromise between these requirements. In adult mammals, brain structural plasticity is strongly reduced with respect to other animal groups in the phylogenetic tree. It persists under different forms, which mainly consist of remodeling of neuronal shape and connectivity, and, to a lesser extent, the production of new neurons. Adult neurogenesis is mainly restricted within two neurogenic niches, yet some gliogenic and neurogenic processes also occur in the so-called non-neurogenic tissue, starting from parenchymal progenitors. In this review we focus on a population of immature, non-newly generated neurons in layer II of the cerebral cortex, which were previously thought to be newly generated since they heavily express the polysialylated form of the neural cell adhesion molecule and doublecortin. These unusual neurons exhibit characteristics defining an additional type of structural plasticity, different from either synaptic plasticity or adult neurogenesis. Evidences concerning their morphology, antigenic features, ultrastructure, phenotype, origin, fate, and reaction to different kind of stimulations are gathered and analyzed. Their possible role is discussed in the context of an enriched complexity and heterogeneity of mammalian brain structural plasticity.
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Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano (TO), and Department of Veterinary Morphophysiology, University of Turin, Turin, Italy.
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Ogawa B, Wang L, Ohishi T, Taniai E, Akane H, Suzuki K, Mitsumori K, Shibutani M. Reversible aberration of neurogenesis targeting late-stage progenitor cells in the hippocampal dentate gyrus of rat offspring after maternal exposure to acrylamide. Arch Toxicol 2012; 86:779-90. [DOI: 10.1007/s00204-012-0801-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 01/04/2012] [Indexed: 11/30/2022]
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Impact of the NCAM derived mimetic peptide plannexin on the acute cellular consequences of a status epilepticus. Neurosci Lett 2011; 501:173-8. [PMID: 21787839 DOI: 10.1016/j.neulet.2011.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 06/27/2011] [Accepted: 07/06/2011] [Indexed: 11/22/2022]
Abstract
Plannexin represents a NCAM-derived peptide mimicking trans-homophilic NCAM interaction, which proved to exert neuroprotective effects in vitro. The effect of plannexin was evaluated in a rat status epilepticus model. As expected, prolonged seizure activity resulted in a pronounced cell loss in hippocampal subregions. The comparison between the vehicle- and plannexin-treated animals with status epilepticus did not reveal neuroprotective effects of plannexin on mature neurons. However, treatment with plannexin partially prevented the reduction in the number of doublecortin-labeled neuronal progenitor cells, which was evident 48h following status epilepticus. In conclusion, the data might give first evidence that plannexin can protect immature neurons in vivo. Future studies are necessary to evaluate whether disease-modifying or preventive effects are observed in models of epileptogenesis.
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Marlatt MW, Philippens I, Manders E, Czéh B, Joels M, Krugers H, Lucassen PJ. Distinct structural plasticity in the hippocampus and amygdala of the middle-aged common marmoset (Callithrix jacchus). Exp Neurol 2011; 230:291-301. [DOI: 10.1016/j.expneurol.2011.05.008] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2010] [Revised: 03/25/2011] [Accepted: 05/06/2011] [Indexed: 01/18/2023]
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Aasebø IEJ, Blankvoort S, Tashiro A. Critical maturational period of new neurons in adult dentate gyrus for their involvement in memory formation. Eur J Neurosci 2011; 33:1094-100. [PMID: 21395853 DOI: 10.1111/j.1460-9568.2011.07608.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Adult dentate gyrus produces new neurons continuously throughout life. Multiple lines of evidence have pointed to the possibility that young neurons during a certain maturational stage mediate an important role in memory processing. In this review, we highlight the existing evidence of a 'critical period' for new neurons in their involvement in memory formation, describe the unique properties of young neurons as potential mechanisms underlying the critical period, and discuss the implications of the critical period for the function of adult neurogenesis.
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Affiliation(s)
- Ida E J Aasebø
- Kavli Institute for Systems Neuroscience and Centre for the Biology of Memory, Faculty of Medicine, Norwegian University of Science and Technology and St. Olavs Hospital, 7030 Trondheim, Norway
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Schoenfeld TJ, Gould E. Stress, stress hormones, and adult neurogenesis. Exp Neurol 2011; 233:12-21. [PMID: 21281629 DOI: 10.1016/j.expneurol.2011.01.008] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 01/18/2011] [Accepted: 01/24/2011] [Indexed: 01/17/2023]
Abstract
The dentate gyrus of the hippocampus continues to produce new neurons throughout adulthood. Adult neurogenesis has been linked to hippocampal function, including learning and memory, anxiety regulation and feedback of the stress response. It is thus not surprising that stress, which affects hippocampal function, also alters the production and survival of new neurons. Glucocorticoids, along with other neurochemicals, have been implicated in stress-induced impairment of adult neurogenesis. Paradoxically, increases in corticosterone levels are sometimes associated with enhanced adult neurogenesis in the dentate gyrus. In these circumstances, the factors that buffer against the suppressive influence of elevated glucocorticoids remain unknown; their discovery may provide clues to reversing pathological processes arising from chronic exposure to aversive stress.
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Affiliation(s)
- Timothy J Schoenfeld
- Department of Psychology, Neuroscience Institute, Princeton University, Princeton, NJ 08544, USA
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D'Alessio L, Konopka H, López EM, Seoane E, Consalvo D, Oddo S, Kochen S, López-Costa JJ. Doublecortin (DCX) immunoreactivity in hippocampus of chronic refractory temporal lobe epilepsy patients with hippocampal sclerosis. Seizure 2011; 19:567-72. [PMID: 20888264 DOI: 10.1016/j.seizure.2010.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 08/06/2010] [Accepted: 09/02/2010] [Indexed: 11/17/2022] Open
Abstract
INTRODUCTION Status epilepticus increases the production of new neurons (hippocampal neurogenesis) and promotes aberrant migration. However chronic experimental models of epilepsy and studies performed in human epilepsy showed controversial results suggesting a reduction in hippocampal neurogenesis in late stages of the disease. Doublecortin (DCX) has been validated to determine alterations in the production of new neurons in the human hippocampus. OBJECTIVES Determine DCX expression in human hippocampal sclerosis (HS) from patients who underwent epilepsy surgery for refractory temporal lobe epilepsy (TLE). METHODS Hippocampal sections of 9 patients with HS and TLE who underwent surgery, were processed using immunoperoxidase for DCX. Archival material from 5 normal post-mortem hippocampus were simultaneously processed. RESULTS Significantly lower staining intensity was observed in DCX-positive neurons localized in dentate gyrus (DG) and in CA1 of epileptic hippocampus; lower DCX reactive area was observed in pyramidal layers of CA1; and a reduced in the mean number of DCX-positive neurons were determined in DG compared to normal hippocampus (p<0.05). CONCLUSIONS This study found a decrease in DCX expression in hippocampus of patients with HS and chronic and refractory TLE suggesting alterations in NG and hippocampal synaptogenesis with potential cognitive and emotional repercussion.
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Affiliation(s)
- Luciana D'Alessio
- Instituto de Biología Celular y Neurociencias, E de Robertis, UBA-CONICET, Buenos Aires, Argentina.
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Pekcec A, Lüpke M, Baumann R, Seifert H, Potschka H. Modulation of neurogenesis by targeted hippocampal irradiation fails to affect kindling progression. Hippocampus 2010; 21:866-76. [PMID: 20865736 DOI: 10.1002/hipo.20802] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2010] [Indexed: 12/31/2022]
Abstract
Changes in the rate of dentate granule cell neurogenesis and in the fate of newborn granule cells have been implicated in the development and progression of epilepsies. Strategies to normalize neurogenesis in chronic epilepsy models are thought to increase our understanding of the functional consequences of aberrant neurogenesis in the epileptic brain. Therefore, we modulated neurogenesis in an amygdala kindling paradigm in rats by targeted irradiation of the hippocampus using a medical linear accelerator device. Selective irradiation normalized the hippocampal cell proliferation rate in kindled animals. Both, in kindled and nonkindled rats the number of BrdU/NeuN-labeled newborn neurons was reduced in response to irradiation. Whereas kindling resulted in a pronounced increase in the number of neuroblasts identified based on doublecortin-labeling, irradiation prevented the expansion of the neuroblast population. Moreover, irradiation counteracted the kindling-associated increase in hilar basal dendrites, and kept the fraction of cells with basal dendrites at control levels. Despite the efficacious modulation of neurogenesis, irradiation did not affect the rate of kindling progression. Both, the number of stimulations as well as the cumulative afterdischarge duration to reach respective seizure stages were comparable in animals with and without irradiation. In addition, pre- and postkindling thresholds as well as seizure parameters recorded at threshold stimulation remained unaffected by irradiation. In conclusion, the fact that the efficacious modulation of neurogenesis by irradiation did not exert any effects on kindling acquisition and kindled seizures suggests that newborn neurons do not critically contribute to the hyperexcitable state in the chronic epilepsy model used.
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Affiliation(s)
- Anton Pekcec
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
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Popov VI, Kraev IV, Banks D, Davies HA, Morenkov ED, Stewart MG, Fesenko EE. Three-dimensional ultrastructural and immunohistochemical study of immature neurons in the subgranular zone of the rat dentate gyrus. Biophysics (Nagoya-shi) 2009. [DOI: 10.1134/s0006350909040174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Nakahara S, Tamura M, Matsuki N, Koyama R. Neuronal hyperactivity sustains the basal dendrites of immature dentate granule cells: time-lapse confocal analysis using hippocampal slice cultures. Hippocampus 2009; 19:379-91. [PMID: 19004014 DOI: 10.1002/hipo.20529] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Dendritic morphogenesis is an essential process for the establishment of proper neural circuitry. In the epileptic hippocampus, mature dentate granule cells (GCs) possess basal dendrites (BDs), which is abnormal and is assumed to contribute to seizure progression. However, there is a lack of direct time-lapse evidence showing that neuronal hyperactivity regulates the dendritic development of GCs. In the present study, we carried out time-lapse confocal analysis of the dendritic morphogenesis of GCs in hippocampal slice cultures that were prepared from postnatal 6-day-old (P6) rats. By electroporating membrane-targeted green fluorescent protein at 5 days in vitro (DIV), we found that most of the Prox1-positive and calbindin-negative immature GCs possessed several BDs and filopodia-rich apical dendrites at 7 DIV. BDs were gradually eliminated from 7 to 9 DIV, and they completely vanished at 14 DIV in all the GCs examined. However, most BDs failed to retract from 7 to 9 DIV, when the GABA(A) receptor antagonist picrotoxin was chronically applied to induce epileptic conditions in the cultures. These effects were blocked by coapplying tetrodotoxin, a sodium channel blocker, thus convincing us that neuronal hyperactivity contributes to the maintenance of BDs. Further, in the picrotoxin-treated cultures, most of the GCs persistently exhibited several BDs even after 14 DIV. In contrast, neither the progressive pruning of the filopodia nor the branch dynamics of the apical dendrites during the culture periods was affected by picrotoxin. These results, for the first time, provide us with direct evidence that neuronal hyperactivity contributes to the stability of pre-existing BDs.
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Affiliation(s)
- Soichiro Nakahara
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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Kraev IV, Godukhin OV, Patrushev IV, Davies HA, Popov VI, Stewart MG. Partial kindling induces neurogenesis, activates astrocytes and alters synaptic morphology in the dentate gyrus of freely moving adult rats. Neuroscience 2009; 162:254-67. [PMID: 19447163 DOI: 10.1016/j.neuroscience.2009.05.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 04/30/2009] [Accepted: 05/10/2009] [Indexed: 12/01/2022]
Abstract
A partial kindling procedure was used to investigate the correlation between focal seizure development and changes in dendritic spine morphology, ongoing neurogenesis and reactive astrogliosis in the adult rat dentate gyrus (DG). The processes of neurogenesis and astrogliosis were investigated using markers for doublecortin (DCX), 5-bromo-2-deoxyuridine (BrdU) and glial fibrillary acidic protein (GFAP). Our data demonstrate that mild focal seizures induce a complex series of cellular events in the DG one day after cessation of partial rapid kindling stimulation consisting (in comparison to control animals that were electrode implanted but unkindled), firstly, of an increase in the number of postmitotic BrdU labeled cells, and secondly, an increase in the number of DCX labeled cells, mainly in subgranular zone. Ultrastructural changes were examined using qualitative electron microscope analysis and 3-D reconstructions of both dendritic spines and postsynaptic densities. Typical features of kindling in comparison to control tissue included translocation of mitochondria to the base of the dendritic spine stalks; a migration of multivesicular bodies into mushroom dendritic spines, and most notably formation of "giant" spinules originating from the head of the spines of DG neurons. These morphological alterations arise at seizure stages 2-3 (focal seizures) in the absence of signs of the severe generalized seizures that are generally recognized as potentially harmful for neuronal cells. We suggest that an increase in ongoing neurogenesis, reactive astrogliosis and dendritic spine reorganization in the DG is the crucial step in the chain of events leading to the progressive development of seizure susceptibility in hippocampal circuits.
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Affiliation(s)
- I V Kraev
- Department of Life Sciences, Faculty of Science, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
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Balu DT, Lucki I. Adult hippocampal neurogenesis: regulation, functional implications, and contribution to disease pathology. Neurosci Biobehav Rev 2008; 33:232-52. [PMID: 18786562 DOI: 10.1016/j.neubiorev.2008.08.007] [Citation(s) in RCA: 272] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 08/13/2008] [Accepted: 08/14/2008] [Indexed: 12/28/2022]
Abstract
It is now well established that the mammalian brain has the capacity to produce new neurons into adulthood. One such region that provides the proper milieu to sustain progenitor cells and is permissive to neuronal fate determination is located in the dentate gyrus of the hippocampus. This review will discuss in detail the complex process of adult hippocampal neurogenesis, including proliferation, differentiation, survival, and incorporation into neuronal networks. The regulation of this phenomenon by a number of factors is described, including neurotransmitter systems, growth factors, paracrine signaling molecules, neuropeptides, transcription factors, endogenous psychotropic systems, sex hormones, stress, and others. This review also addresses the functional significance of adult born hippocampal granule cells with regard to hippocampal circuitry dynamics and behavior. Furthermore, the relevance of perturbations in adult hippocampal neurogenesis to the pathophysiology of various disease states, including depression, schizophrenia, epilepsy, and diabetes are examined. Finally, this review discusses the potential of using hippocampal neurogenesis as a therapeutic target for these disorders.
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Affiliation(s)
- Darrick T Balu
- Department of Pharmacology, University of Pennsylvania, Philadelphia, PA, USA
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36
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Shapiro LA, Ribak CE, Jessberger S. Structural changes for adult-born dentate granule cells after status epilepticus. Epilepsia 2008; 49 Suppl 5:13-8. [DOI: 10.1111/j.1528-1167.2008.01633.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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37
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Treves A, Tashiro A, Witter MP, Moser EI. What is the mammalian dentate gyrus good for? Neuroscience 2008; 154:1155-72. [PMID: 18554812 DOI: 10.1016/j.neuroscience.2008.04.073] [Citation(s) in RCA: 197] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2008] [Revised: 04/12/2008] [Accepted: 04/28/2008] [Indexed: 01/01/2023]
Abstract
In the mammalian hippocampus, the dentate gyrus (DG) is characterized by sparse and powerful unidirectional projections to CA3 pyramidal cells, the so-called mossy fibers (MF). The MF form a distinct type of synapses, rich in zinc, that appear to duplicate, in terms of the information they convey, what CA3 cells already receive from entorhinal cortex layer II cells, which project both to the DG and to CA3. Computational models have hypothesized that the function of the MF is to enforce a new, well-separated pattern of activity onto CA3 cells, to represent a new memory, prevailing over the interference produced by the traces of older memories already stored on CA3 recurrent collateral connections. Although behavioral observations support the notion that the MF are crucial for decorrelating new memory representations from previous ones, a number of findings require that this view be reassessed and articulated more precisely in the spatial and temporal domains. First, neurophysiological recordings indicate that the very sparse dentate activity is concentrated on cells that display multiple but disorderly place fields, unlike both the single fields typical of CA3 and the multiple regular grid-aligned fields of medial entorhinal cortex. Second, neurogenesis is found to occur in the adult DG, leading to new cells that are functionally added to the existing circuitry, and may account for much of its ongoing activity. Third, a comparative analysis suggests that only mammals have evolved a DG, despite some of its features being present also in reptiles, whereas the avian hippocampus seems to have taken a different evolutionary path. Thus, we need to understand both how the mammalian dentate operates, in space and time, and whether evolution, in other vertebrate lineages, has offered alternative solutions to the same computational problems.
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Affiliation(s)
- A Treves
- Kavli Institute for Systems Neuroscience and Centre for the Biology of Memory, Norwegian University for Science and Technology, Trondheim, Norway.
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Ngwenya LB, Rosene DL, Peters A. An ultrastructural characterization of the newly generated cells in the adult monkey dentate gyrus. Hippocampus 2008; 18:210-20. [DOI: 10.1002/hipo.20384] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Keith JR, Priester C, Ferguson M, Salling M, Hancock A. Persistent increases in the pool of doublecortin-expressing neurons in the hippocampus following spatial navigation training. Behav Brain Res 2007; 188:391-7. [PMID: 18199494 DOI: 10.1016/j.bbr.2007.11.026] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2007] [Revised: 11/21/2007] [Accepted: 11/27/2007] [Indexed: 12/23/2022]
Abstract
In addition to its role in neuronal migration during embryonic development, doublecortin (DCX) plays a role in hippocampal neurogenesis across the lifespan. Hippocampal neurons exhibit a high degree of synaptic plasticity while they are in the DCX phase. While previous studies have reported that behavioral training on hippocampus-dependent tasks can enhance neuron survival, little was known about the stage of development of those neurons and, particularly, whether a large pool of the surviving new neurons remains in the DCX phase for a prolonged period after training. Here we report that spatial navigation training increases the pool of neurons that are in the DCX phase 4 weeks after training ended. Thus, the stock of DCX-expressing neurons in the hippocampus is affected by whether a hippocampus-dependent task has been encountered during the preceding few weeks.
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Affiliation(s)
- Julian R Keith
- Department of Psychology, University of North Carolina at Wilmington, Wilmington, NC 28403-5612, USA.
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40
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Ribak CE, Shapiro LA. Dendritic development of newly generated neurons in the adult brain. BRAIN RESEARCH REVIEWS 2007; 55:390-4. [PMID: 17239443 PMCID: PMC2072906 DOI: 10.1016/j.brainresrev.2006.12.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 12/13/2006] [Accepted: 12/15/2006] [Indexed: 11/18/2022]
Abstract
Ramon y Cajal described the fundamental morphology of the dendritic and axonal growth cones of neurons during development. However, technical limitations at the time prevented him from describing such growth cones from newborn neurons in the adult brain. The phenomenon of adult neurogenesis is briefly reviewed, and the structural description of dendritic and axonal outgrowth for these newly generated neurons in the adult brain is discussed. Axonal outgrowth into the hilus and CA3 region of the hippocampus occurs later than the outgrowth of dendrites into the molecular layer, and the ultrastructural analysis of axonal outgrowth has yet to be completed. In contrast, growth cones on dendrites from newborn neurons in the adult dentate gyrus have been described and this observation suggests that dendrites in adult brains grow in a similar way to those found in immature brains. However, dendrites in adult brains have to navigate through a denser neuropil and a more complex cell layer. Therefore, some aspects of dendritic outgrowth of neurons born in the adult dentate gyrus are different as compared to that found in development. These differences include the radial process of radial glial cells acting as a lattice to guide apical dendritic growth through the granule cell layer and a much thinner dendrite to grow through the neuropil of the molecular layer. Therefore, similarities and differences exist for dendritic outgrowth from newborn neurons in the developing and adult brain.
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Affiliation(s)
- Charles E Ribak
- Department of Anatomy & Neurobiology, University of California at Irvine, Irvine, CA 92697-1275, USA.
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Rai KS, Hattiangady B, Shetty AK. Enhanced production and dendritic growth of new dentate granule cells in the middle-aged hippocampus following intracerebroventricular FGF-2 infusions. Eur J Neurosci 2007; 26:1765-79. [PMID: 17883411 DOI: 10.1111/j.1460-9568.2007.05820.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Declined production and diminished dendritic growth of new dentate granule cells in the middle-aged and aged hippocampus are correlated with diminished concentration of fibroblast growth factor-2 (FGF-2). This study examined whether increased FGF-2 concentration in the milieu boosts both production and dendritic growth of new dentate granule cells in the middle-aged hippocampus. The FGF-2 or vehicle was infused into the posterior lateral ventricle of middle-aged Fischer (F)344 rats for 2 weeks using osmotic minipumps. New cells born during the first 12 days of infusions were labeled via daily intraperitoneal injections of 5'-bromodeoxyuridine (BrdU) and analysed at 10 days after the last BrdU injection. Measurement of BrdU(+) cells revealed a considerably enhanced number of new cells in the subgranular zone (SGZ) and granule cell layer (GCL) of the dentate gyrus (DG) ipsilateral to FGF-2 infusions. Characterization of beta-III tubulin(+) neurons among newly born cells suggested an increased addition of new neurons to the SGZ/GCL ipsilateral to FGF-2 infusions. Quantification of DG neurogenesis at 8 days post-infusions via doublecortin (DCX) immunostaining also revealed the presence of an enhanced DG neurogenesis ipsilateral to FGF-2 infusions. Furthermore, DCX(+) neurons in FGF-2-infused rats exhibited enhanced dendritic growth compared with their counterparts in vehicle-infused rats. Thus, subchronic infusion of FGF-2 is efficacious for stimulating an enhanced DG neurogenesis from neural stem/progenitor cells in the middle-aged hippocampus. As dentate neurogenesis is important for hippocampal-dependent learning and memory and DG long-term potentiation, strategies that maintain increased FGF-2 concentration during ageing may be beneficial for thwarting some of the age-related cognitive impairments.
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Affiliation(s)
- Kiranmai S Rai
- Department of Surgery (Neurosurgery), Duke University Medical Center, Durham, NC 27710, USA
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Shapiro LA, Ng KL, Kinyamu R, Whitaker-Azmitia P, Geisert EE, Blurton-Jones M, Zhou QY, Ribak CE. Origin, migration and fate of newly generated neurons in the adult rodent piriform cortex. Brain Struct Funct 2007; 212:133-48. [PMID: 17764016 DOI: 10.1007/s00429-007-0151-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 06/14/2007] [Indexed: 12/16/2022]
Abstract
Newly generated neurons are continuously added to the olfactory epithelium and olfactory bulbs of adult mammals. Studies also report newly generated neurons in the piriform cortex, the primary cortical projection site of the olfactory bulbs. The current study used BrdU-injection paradigms, and in vivo and in vitro DiI tracing methods to address three fundamental issues of these cells: their origin, migratory route and fate. The results show that 1 day after a BrdU-injection, BrdU/DCX double-labeled cells appear deep to the ventricular subependyma, within the white matter. Such cells appear further ventral and caudal in the ensuing days, first appearing in the rostral piriform cortex of mice at 2 days after the BrdU-injection, and at 4 days in the rat. In the caudal piriform cortex, BrdU/DCX labeled cells first appear at 4 days after the injection in mice and 7 days in rats. The time it takes for these cells to appear in the piriform cortex and the temporal distribution pattern suggest that they migrate from outside this region. DiI tracing methods confirmed a migratory route to the piriform cortex from the ventricular subependyma. The presence of BrdU/NeuN labeled cells as early as 7 days after a BrdU injection in mice and 10 days in the rat and lasting as long as 41 days indicates that some of these cells have extended survival durations in the adult piriform cortex.
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Affiliation(s)
- Lee A Shapiro
- Department of Anatomy and Neurobiology, School of Medicine, University of California at Irvine, Irvine, CA 92697-1275, USA
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Arisi GM, Garcia-Cairasco N. Doublecortin-positive newly born granule cells of hippocampus have abnormal apical dendritic morphology in the pilocarpine model of temporal lobe epilepsy. Brain Res 2007; 1165:126-34. [PMID: 17662262 DOI: 10.1016/j.brainres.2007.06.037] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2007] [Revised: 06/06/2007] [Accepted: 06/07/2007] [Indexed: 12/22/2022]
Abstract
Here, we describe dentate gyrus newly born granule cells morphology in rats' temporal lobe epilepsy pilocarpine model. Digital reconstruction of doublecortin-positive neurons revealed that apical dendrites had the same total length and number of nodes in epileptic and control animals. Nonetheless, concentric spheres analyses revealed that apical dendrites spatial distribution was radically altered in epileptic animals. The apical dendrites had more bifurcations inside the granular cell layer and more terminations in the inner molecular layer of epileptic dentate gyrus. Branch order analyses showed that second- and third-order dendrites were shorter in epileptic animals. Apical dendrites were concentrated in regions like the inner molecular layer where granular neuron axons, named mossy fibers, sprout in epileptic animals. The combination of altered dendritic morphology and number enhancement of the new granular neurons suggests a deleterious role of hippocampal neurogenesis in epileptogenesis. Being more numerous and with dendrites concentrated in regions where aberrant axon terminals sprout, the new granular neurons could contribute to the slow epileptogenesis at hippocampal circuits commonly observed in temporal lobe epilepsy.
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Affiliation(s)
- Gabriel Maisonnave Arisi
- Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, 14049-900, Brazil
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Shapiro LA, Figueroa-Aragon S, Ribak CE. Newly generated granule cells show rapid neuroplastic changes in the adult rat dentate gyrus during the first five days following pilocarpine-induced seizures. Eur J Neurosci 2007; 26:583-92. [PMID: 17686039 DOI: 10.1111/j.1460-9568.2007.05662.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Long-term neuroplastic changes to dentate granule cells have been reported after seizures and were shown to contribute to recurrent excitatory circuitry. These changes include increased numbers of newborn granule cells, sprouted mossy fibers, granule cell layer dispersion, increased hilar ectopic granule cells and formation of hilar basal dendrites on granule cells. The goal of the current study was to determine the acute progression of neuroplastic changes involving newly generated granule cells after pilocarpine-induced seizures. Doublecortin (DCX) immunocytochemical preparations were used to examine the newly generated granule cells 1-5 days after seizures were induced. The results showed that there are rapid neuroplastic changes to the DCX-labeled cells. At 1 day after seizures were induced, there were significant increases in the percentage of DCX-labeled cells with hilar basal dendrites and in the progenitor cell population. At 2 days after seizures were induced, an increase in the thickness of the layer of DCX-labeled cells occurred. At 3 days after seizures were induced, the number of DCX-labeled cells was significantly increased. At 4 days after seizures were induced, developing synapses were observed on DCX-labeled hilar basal dendrites. Thus, newly generated granule cells in the adult dentate gyrus display neuroplastic changes by 1 day after pilocarpine-induced seizures and further changes occur to this population of cells in the subsequent 4 days. The presence of synapses, albeit developing ones, on hilar basal dendrites during this period indicates that newly generated granule cells become rapidly incorporated into dentate gyrus circuitry following seizures.
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Affiliation(s)
- Lee A Shapiro
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697-1275, USA
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Seki T, Namba T, Mochizuki H, Onodera M. Clustering, migration, and neurite formation of neural precursor cells in the adult rat hippocampus. J Comp Neurol 2007; 502:275-90. [PMID: 17348003 DOI: 10.1002/cne.21301] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Adult neurogenesis occurs in the subgranular zone and innermost part of the dentate granule cell layer. To examine how neural precursor cells proliferate, migrate, and extend their neurites, we performed BrdU- and improved retrovirus-green fluorescence protein (GFP)-labeling analyses. Soon after labeling the majority of BrdU+ cells and GFP+ cells expressed Ki67, a cell cycle marker, and formed clusters together with PSA+ neuroblasts. Most of the Ki67+ proliferating cells expressed Hu, an immature and mature neuronal marker, and the subpopulation expressed both Hu+ and GFAP+. In the clusters, Ki67+ and PSA+ cells strongly expressed beta-catenin and N-cadherin, but PSA+ cells outside the clusters did not. Therefore, it was mainly Hu+ neuronal precursor cells that proliferated within clusters in which the cluster cells are closely associated via cell adhesion molecules, such as N-cadherin/beta-cateninIn and PSA. The newly generated cells appeared to stay in the clusters for a few days and then disperse around the clusters. The findings of this in vivo analysis and in vitro time-lapse imaging of early postnatal hippocampal slices support the notion that most postmitotic neuroblasts migrate tangentially from clusters, extending tangentially oriented processes, one of which often retains close contact with the clusters, and finally extend radial processes, or prospective apical dendrites. These results suggest that the clustering cells and tangentially migrating cells have a systematic cellular arrangement and intercellular interaction.
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Affiliation(s)
- Tatsunori Seki
- Department of Anatomy, Juntendo University School of Medicine, Tokyo, Japan.
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Chawla MK, Barnes CA. Hippocampal granule cells in normal aging: insights from electrophysiological and functional imaging experiments. PROGRESS IN BRAIN RESEARCH 2007; 163:661-78. [PMID: 17765744 DOI: 10.1016/s0079-6123(07)63036-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Normal aging, in the absence of neurodegenerative disease, can provide important insights into the mechanisms by which the brain can maintain cognitive abilities across the lifespan. Hippocampal-dependent memory processes can become vulnerable as age advances. The focus of this chapter is the contribution of hippocampal granule cells to cognitive impairments that are observed during aging. A number of alterations in structure, function, and gene expression have been observed in aged granule cells, any of which may lead to adaptive, compensatory or detrimental consequences to hippocampal function. As the average life span of humans continues to increase, those who reach 100 years or beyond is more common. Individuals that have aged successfully, and exhibit high levels of cognitive ability can provide useful clues into the enormous potential possessed by the mammalian brain.
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Affiliation(s)
- Monica K Chawla
- Arizona Research Laboratories Division of Neural Systems, Memory and Aging, University of Arizona, Tucson, AZ 85724, USA
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47
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Ribak CE, Shapiro LA. Ultrastructure and synaptic connectivity of cell types in the adult rat dentate gyrus. PROGRESS IN BRAIN RESEARCH 2007; 163:155-66. [PMID: 17765717 DOI: 10.1016/s0079-6123(07)63009-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The rat hippocampal dentate gyrus is an extensively studied structural component of the limbic system. It is the first station in the classical tri-synaptic circuit of the hippocampus in that its major input arises from the entorhinal cortex via the perforant pathway. The second part of this circuit arises from the projection cells of the dentate gyrus, the granule cells, which send their axons to the pyramidal cells of CA3. Within the dentate gyrus, there also is an extensive inhibitory network of cells that are involved in synchronizing the rhythmic firing of the granule cells. This chapter provides a review of the ultrastructural features and synaptic connectivity of both projection cells and local circuit neurons in the dentate gyrus.
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Affiliation(s)
- Charles E Ribak
- Department of Anatomy & Neurobiology, University of California at Irvine, Irvine, CA 92697-1275, USA.
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48
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Ramirez-Amaya V, Marrone DF, Gage FH, Worley PF, Barnes CA. Integration of new neurons into functional neural networks. J Neurosci 2006; 26:12237-41. [PMID: 17122048 PMCID: PMC6675440 DOI: 10.1523/jneurosci.2195-06.2006] [Citation(s) in RCA: 246] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although it is established that new granule cells can be born and can survive in the adult mammalian hippocampus, there remains some question concerning the functional integration of these neurons into behaviorally relevant neural networks. By using high-resolution confocal microscopy, we have applied a new strategy to address the question of functional integration of newborn neurons into networks that mediate spatial information processing and memory formation. Exploration-induced expression of the immediate-early gene Arc in hippocampal cells has been linked to cellular activity observed in electrophysiological recordings under the same behavioral conditions. We investigated whether mature (5-month-old), newborn granule cells express Arc in response to a discrete spatial experience by detecting the expression of Arc in combination with NeuN (neuron-specific nuclear protein)-positive and bromodeoxyuridine-positive cells. We found that mature new granule cells do indeed express Arc in response to an exploration experience, supporting the idea that these cells are well integrated into hippocampal circuits. The proportion of mature newborn neurons that expressed Arc in response to exploration, however, was significantly higher (approximately 2.8%) than the proportion of cells that expressed Arc in the already existing population of granule cells (approximately 1.6%; p < 0.01). This finding extends previous data suggesting that the cellular physiology of newborn granule neurons differs from that of the existing population by indicating that these properties are retained in mature adult-generated neurons. Thus, these data have interesting implications for network models of spatial information processing and the role of hippocampal circuits in memory, indicating that mature new neurons are selectively recruited into hippocampal cell assemblies in higher proportions than older cells.
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Affiliation(s)
- Victor Ramirez-Amaya
- Arizona Research Laboratories Division of Neural Systems, Memory, and Aging and
- Departamento de Neurobiologia Conductual y Cognitiva, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro 76230, México
| | - Diano F. Marrone
- Arizona Research Laboratories Division of Neural Systems, Memory, and Aging and
| | - Fred H. Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, and
| | - Paul F. Worley
- Departments of Neuroscience and Neurology, Johns Hopkins University, Baltimore, Maryland 21218
| | - Carol A. Barnes
- Arizona Research Laboratories Division of Neural Systems, Memory, and Aging and
- Departments of Psychology and Neurology, University of Arizona, Tucson, Arizona 85724
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Variability of doublecortin-associated dendrite maturation in adult hippocampal neurogenesis is independent of the regulation of precursor cell proliferation. BMC Neurosci 2006; 7:77. [PMID: 17105671 PMCID: PMC1657022 DOI: 10.1186/1471-2202-7-77] [Citation(s) in RCA: 295] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 11/15/2006] [Indexed: 11/28/2022] Open
Abstract
Background In the course of adult hippocampal neurogenesis most regulation takes place during the phase of doublecortin (DCX) expression, either as pro-proliferative effect on precursor cells or as survival-promoting effect on postmitotic cells. We here obtained quantitative data about the proliferative population and the dynamics of postmitotic dendrite development during the period of DCX expression. The question was, whether any indication could be obtained that the initiation of dendrite development is timely bound to the exit from the cell cycle. Alternatively, the temporal course of morphological maturation might be subject to additional regulatory events. Results We found that (1) 20% of the DCX population were precursor cells in cell cycle, whereas more than 70% were postmitotic, (2) the time span until newborn cells had reached the most mature stage associated with DCX expression varied between 3 days and several weeks, (3) positive or negative regulation of precursor cell proliferation did not alter the pattern and dynamics of dendrite development. Dendrite maturation was largely independent of close contacts to astrocytes. Conclusion These data imply that dendrite maturation of immature neurons is initiated at varying times after cell cycle exit, is variable in duration, and is controlled independently of the regulation of precursor cell proliferation. We conclude that in addition to the major regulatory events in cell proliferation and selective survival, additional micro-regulatory events influence the course of adult hippocampal neurogenesis.
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50
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Hattiangady B, Shetty AK. Aging does not alter the number or phenotype of putative stem/progenitor cells in the neurogenic region of the hippocampus. Neurobiol Aging 2006; 29:129-47. [PMID: 17092610 PMCID: PMC3612500 DOI: 10.1016/j.neurobiolaging.2006.09.015] [Citation(s) in RCA: 186] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2006] [Revised: 08/09/2006] [Accepted: 09/13/2006] [Indexed: 12/20/2022]
Abstract
To investigate whether dramatically waned dentate neurogenesis during aging is linked to diminution in neural stem/progenitor cell (NSC) number, we counted cells immunopositive for Sox-2 (a putative marker of NSCs) in the subgranular zone (SGZ) of young, middle-aged and aged F344 rats. The young SGZ comprised approximately 50,000 Sox-2+ cells and this amount did not diminish with aging. Quantity of GFAP+ cells and vimentin+ radial glia also remained stable during aging in this region. Besides, in all age groups, analogous fractions of Sox-2+ cells expressed GFAP (astrocytes/NSCs), NG-2 (oligodendrocyte-progenitors/NSCs), vimentin (radial glia), S-100beta (astrocytes) and doublecortin (new neurons). Nevertheless, analyses of Sox-2+ cells with proliferative markers insinuated an increased quiescence of NSCs with aging. Moreover, the volume of rat-endothelial-cell-antigen-1+ capillaries (vascular-niches) within the SGZ exhibited an age-related decline, resulting in an increased expanse between NSCs and capillaries. Thus, decreased dentate neurogenesis during aging is not attributable to altered number or phenotype of NSCs. Instead, it appears to be an outcome of increased quiescence of NSCs due to changes in NSC milieu.
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Affiliation(s)
- Bharathi Hattiangady
- Department of Surgery (Neurosurgery), Duke University Medical Center, Durham, NC 27710, United States
- Medical Research and Surgery Services, Veterans Affairs Medical Center, Durham, NC 27705, United States
| | - Ashok K. Shetty
- Department of Surgery (Neurosurgery), Duke University Medical Center, Durham, NC 27710, United States
- Medical Research and Surgery Services, Veterans Affairs Medical Center, Durham, NC 27705, United States
- Corresponding author at: Division of Neurosurgery, DUMC Box 3807, Duke University Medical Center, Durham, NC 27710, United States. Tel.: +1 919 286 0411x7096; fax: +1 919 286 4662., (A.K. Shetty)
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