1
|
Zhou Z, Jiang WJ, Li L, Si JQ. The effects of noise exposure on hippocampal cognition in C57BL/6 mice via transcriptomics. Biochem Biophys Res Commun 2024; 690:149257. [PMID: 38016245 DOI: 10.1016/j.bbrc.2023.149257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 10/27/2023] [Accepted: 11/14/2023] [Indexed: 11/30/2023]
Abstract
BACKGROUND Noise is an important environmental stressor in the industrialized world and has received increasing attention in recent years. Although epidemiological research has extensively demonstrated the relationship between noise and cognitive impairment, the specific molecular mechanisms and targets remain to be fully explored and understood. METHODS To address this issue, 5-month-old C57BL/6 mice were divided into two groups, with one group exposed to white noise at 98 dB. The effects of noise on cognition in mice were investigated through molecular biology and behavioral experiments. Subsequently, transcriptomic sequencing of the hippocampus in both groups of mice was performed and enrichment analysis of differentially expressed genes (DEGs) was conducted using KEGG and GO databases. Furthermore, LASSO analysis was used to further narrow down the relevant DEGs, followed by enrichment analysis of these genes using KEGG and GO databases. The DEGs were further validated by rt-qPCR. RESULTS Following noise exposure, the hippocampus levels of inflammation-related factors increased, the phosphorylation of Tau protein increased, the postsynaptic density protein decreased, the number of Nissl bodies decreased, and cell shrinkage in the hippocampus increased. Moreover, the behavioral experiments manifest characteristics indicative of a decline in cognitive.A total of 472 DEGs were identified through transcriptomic analysis, and seven relevant genes were screened by the LASSO algorithm, which were further validated by PCR to confirm their consistency with the omics results. CONCLUSION In conclusion, noise exposure affects cognitive function in mice through multiple pathways, and the omics results provide new evidence for the cognitive impairment induced by noise exposure.
Collapse
Affiliation(s)
- Zan Zhou
- Department of Physiology, Medical College of Shihezi University, Shihezi, Xinjiang, 832000, China; Department of Physiology, Medical College of Jiaxing University, Jiaxing, Zhejiang, 314000, China; The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University, Shihezi, 832000, Xinjiang, China
| | - Wen-Jun Jiang
- Department of Physiology, Medical College of Jiaxing University, Jiaxing, Zhejiang, 314000, China; Department of Physiology, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, 310051, China
| | - Li Li
- Department of Physiology, Medical College of Jiaxing University, Jiaxing, Zhejiang, 314000, China.
| | - Jun-Qiang Si
- Department of Physiology, Medical College of Shihezi University, Shihezi, Xinjiang, 832000, China; The Key Laboratory of Xinjiang Endemic and Ethnic Diseases, Medical College of Shihezi University, Shihezi, 832000, Xinjiang, China.
| |
Collapse
|
2
|
Salmina AB, Alexandrova OP, Averchuk AS, Korsakova SA, Saridis MR, Illarioshkin SN, Yurchenko SO. Current progress and challenges in the development of brain tissue models: How to grow up the changeable brain in vitro? J Tissue Eng 2024; 15:20417314241235527. [PMID: 38516227 PMCID: PMC10956167 DOI: 10.1177/20417314241235527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Abstract
In vitro modeling of brain tissue is a promising but not yet resolved problem in modern neurobiology and neuropharmacology. Complexity of the brain structure and diversity of cell-to-cell communication in (patho)physiological conditions make this task almost unachievable. However, establishment of novel in vitro brain models would ultimately lead to better understanding of development-associated or experience-driven brain plasticity, designing efficient approaches to restore aberrant brain functioning. The main goal of this review is to summarize the available data on methodological approaches that are currently in use, and to identify the most prospective trends in development of neurovascular unit, blood-brain barrier, blood-cerebrospinal fluid barrier, and neurogenic niche in vitro models. The manuscript focuses on the regulation of adult neurogenesis, cerebral microcirculation and fluids dynamics that should be reproduced in the in vitro 4D models to mimic brain development and its alterations in brain pathology. We discuss approaches that are critical for studying brain plasticity, deciphering the individual person-specific trajectory of brain development and aging, and testing new drug candidates in the in vitro models.
Collapse
Affiliation(s)
- Alla B Salmina
- Brain Science Institute, Research Center of Neurology, Moscow, Russia
- Bauman Moscow State Technical University, Moscow, Russia
| | - Olga P Alexandrova
- Brain Science Institute, Research Center of Neurology, Moscow, Russia
- Bauman Moscow State Technical University, Moscow, Russia
| | - Anton S Averchuk
- Brain Science Institute, Research Center of Neurology, Moscow, Russia
- Bauman Moscow State Technical University, Moscow, Russia
| | | | | | | | | |
Collapse
|
3
|
Lam J, Lee J, Liu CY, Lozano AM, Lee DJ. Deep Brain Stimulation for Alzheimer's Disease: Tackling Circuit Dysfunction. Neuromodulation 2020; 24:171-186. [PMID: 33377280 DOI: 10.1111/ner.13305] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/07/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Treatments for Alzheimer's disease are urgently needed given its enormous human and economic costs and disappointing results of clinical trials targeting the primary amyloid and tau pathology. On the other hand, deep brain stimulation (DBS) has demonstrated success in other neurological and psychiatric disorders leading to great interest in DBS as a treatment for Alzheimer's disease. MATERIALS AND METHODS We review the literature on 1) circuit dysfunction in Alzheimer's disease and 2) DBS for Alzheimer's disease. Human and animal studies are reviewed individually. RESULTS There is accumulating evidence of neural circuit dysfunction at the structural, functional, electrophysiological, and neurotransmitter level. Recent evidence from humans and animals indicate that DBS has the potential to restore circuit dysfunction in Alzheimer's disease, similarly to other movement and psychiatric disorders, and may even slow or reverse the underlying disease pathophysiology. CONCLUSIONS DBS is an intriguing potential treatment for Alzheimer's disease, targeting circuit dysfunction as a novel therapeutic target. However, further exploration of the basic disease pathology and underlying mechanisms of DBS is necessary to better understand how circuit dysfunction can be restored. Additionally, robust clinical data in the form of ongoing phase III clinical trials are needed to validate the efficacy of DBS as a viable treatment.
Collapse
Affiliation(s)
- Jordan Lam
- USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA.,Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA
| | - Justin Lee
- USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA.,Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA
| | - Charles Y Liu
- USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA.,Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA
| | - Andres M Lozano
- Division of Neurological Surgery, Department of Surgery, Toronto Western Hospital, University of Toronto, Toronto, ON, M5T 2S8, Canada
| | - Darrin J Lee
- USC Neurorestoration Center, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA.,Department of Neurological Surgery, Keck School of Medicine of USC, Los Angeles, CA, 90033, USA
| |
Collapse
|
4
|
Manohar S, Adler HJ, Chen GD, Salvi R. Blast-induced hearing loss suppresses hippocampal neurogenesis and disrupts long term spatial memory. Hear Res 2020; 395:108022. [PMID: 32663733 PMCID: PMC9063718 DOI: 10.1016/j.heares.2020.108022] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/07/2020] [Accepted: 06/11/2020] [Indexed: 12/16/2022]
Abstract
Acoustic information transduced by cochlear hair cells is continuously relayed from the auditory pathway to other sensory, motor, emotional and cognitive centers in the central nervous system. Human epidemiological studies have suggested that hearing loss is a risk factor for dementia and cognitive decline, but the mechanisms contributing to these memory and cognitive impairments are poorly understood. To explore these issues in a controlled experimental setting, we exposed adult rats to a series of intense blast wave exposures that significantly reduced the neural output of the cochlea. Several weeks later, we used the Morris Water Maze test, a hippocampal-dependent memory task, to assess the ability of Blast Wave and Control rats to learn a spatial navigation task (memory acquisition) and to remember what they had learned (spatial memory retention) several weeks earlier. The elevated plus maze and open field arena were used to test for anxiety-like behaviors. Afterwards, hippocampal cell proliferation and neurogenesis were evaluated using bromodeoxyuridine (BrdU), doublecortin (DCX), and Neuronal Nuclei (NeuN) immunolabeling. The Blast Wave and Control rats learned the spatial navigation task equally well and showed no differences on tests of anxiety. However, the Blast Wave rats performed significantly worse on the spatial memory retention task, i.e., remembering where they had been two weeks earlier. Deficits on the spatial memory retention task were associated with significant decreases in hippocampal cell proliferation and neurogenesis. Our blast wave results are consistent with other experimental manipulations that link spatial memory retention deficits (long term memory) with decreased cell proliferation and neurogenesis in the hippocampus. These results add to the growing body of knowledge linking blast-induced cochlear hearing loss with the cognitive deficits often seen in combat personnel and provide mechanistic insights into these extra auditory disorders that could lead to therapeutic interventions.
Collapse
Affiliation(s)
- Senthilvelan Manohar
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Henry J Adler
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Guang-Di Chen
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA
| | - Richard Salvi
- Center for Hearing and Deafness, State University of New York at Buffalo, 137 Cary Hall, 3435 Main Street, Buffalo, NY, 14214, USA.
| |
Collapse
|
5
|
Ramos Costa AP, Levone BR, Gururajan A, Moloney G, Hoeller AA, Lino-de-Oliveira C, Dinan TG, O'Leary OF, Monteiro de Lima TC, Cryan JF. Enduring effects of muscarinic receptor activation on adult hippocampal neurogenesis, microRNA expression and behaviour. Behav Brain Res 2019; 362:188-198. [PMID: 30650342 DOI: 10.1016/j.bbr.2018.12.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/17/2018] [Accepted: 12/22/2018] [Indexed: 12/27/2022]
Abstract
The cholinergic system is one of the most important neurotransmitter systems in the brain with key roles in autonomic control and the regulation of cognitive and emotional responses. However, the precise mechanism by which the cholinergic system influences behaviour is unclear. Adult hippocampal neurogenesis (AHN) is a potential mediator in this context based on evidence, which has identified this process as putative mechanism of antidepressant action. More recently, post-transcriptional regulation by microRNAs is another candidate mechanism based on its involvement in the regulation of AHN and neurotransmission. Taking into account this background, we evaluated the behavioural effects of a non-convulsant dose of pilocarpine - a non-selective muscarinic receptor (mAChR) agonist - in adult Wistar rats. Furthermore, we quantified the expression of different microRNAs implicated in the regulation of AHN. Our results suggests that pilocarpine treatment increases AHN in the granular cell layer but also induced ectopic neurogenesis. Pilocarpine treatment reduced immobility time in forced swimming test but did not affect fear conditioning response, sucrose preference or novelty supressed feeding behaviour. In addition, treatment with pilocarpine down-regulated the expression of 6 microRNAs implicated in the regulation of neurotrophin signalling and axon guidance pathways. Therefore, we suggest that the low-dose stimulation of the cholinergic system is sufficient to alter AHN of rats through post-transcriptional mechanisms, which might contribute to long-lasting behavioural effects.
Collapse
Affiliation(s)
- Ana Paula Ramos Costa
- APC Microbiome Ireland, University College Cork, Ireland; Graduate Program in Medical Sciences, Federal University of Santa Catarina, Brazil
| | | | - Anand Gururajan
- APC Microbiome Ireland, University College Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Gerard Moloney
- Department of Anatomy and Neuroscience, University College Cork, Ireland
| | - Alexandre A Hoeller
- Graduate Program in Medical Sciences, Federal University of Santa Catarina, Brazil
| | | | | | - Olivia F O'Leary
- APC Microbiome Ireland, University College Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Ireland
| | | | - John F Cryan
- APC Microbiome Ireland, University College Cork, Ireland; Department of Anatomy and Neuroscience, University College Cork, Ireland.
| |
Collapse
|
6
|
Káradóttir RT, Kuo CT. Neuronal Activity-Dependent Control of Postnatal Neurogenesis and Gliogenesis. Annu Rev Neurosci 2018; 41:139-161. [PMID: 29618286 DOI: 10.1146/annurev-neuro-072116-031054] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The addition of new neurons and oligodendroglia in the postnatal and adult mammalian brain presents distinct forms of gray and white matter plasticity. Substantial effort has been devoted to understanding the cellular and molecular mechanisms controlling postnatal neurogenesis and gliogenesis, revealing important parallels to principles governing the embryonic stages. While during central nervous system development, scripted temporal and spatial patterns of neural and glial progenitor proliferation and differentiation are necessary to create the nervous system architecture, it remains unclear what driving forces maintain and sustain postnatal neural stem cell (NSC) and oligodendrocyte progenitor cell (OPC) production of new neurons and glia. In recent years, neuronal activity has been identified as an important modulator of these processes. Using the distinct properties of neurotransmitter ionotropic and metabotropic channels to signal downstream cellular events, NSCs and OPCs share common features in their readout of neuronal activity patterns. Here we review the current evidence for neuronal activity-dependent control of NSC/OPC proliferation and differentiation in the postnatal brain, highlight some potential mechanisms used by the two progenitor populations, and discuss future studies that might advance these research areas further.
Collapse
Affiliation(s)
- Ragnhildur T Káradóttir
- Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, United Kingdom; .,Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, United Kingdom
| | - Chay T Kuo
- Departments of Cell Biology and Neurobiology, Duke University School of Medicine, Durham, North Carolina 27710, USA; .,Preston Robert Tisch Brain Tumor Center, Duke University Medical Center, Durham, North Carolina 27710, USA.,Institute for Brain Sciences, Duke University, Durham, North Carolina 27708, USA
| |
Collapse
|
7
|
Blusztajn JK, Rinnofner J. Intrinsic Cholinergic Neurons in the Hippocampus: Fact or Artifact? Front Synaptic Neurosci 2016; 8:6. [PMID: 27014052 PMCID: PMC4785141 DOI: 10.3389/fnsyn.2016.00006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 02/26/2016] [Indexed: 11/13/2022] Open
Abstract
It is generally agreed that hippocampal acetylcholine (ACh) is synthesized and released exclusively from the terminals of the long-axon afferents whose cell bodies reside in the medial septum and diagonal band. The search for intrinsic cholinergic neurons in the hippocampus has a long history; however evidence for the existence of these neurons has been inconsistent, with most investigators failing to detect them using in situ hybridization or immunohistochemical staining of the cholinergic markers, choline acetyltransferase (ChAT) or vesicular acetylcholine transporter (VAChT). Advances in the use of bacterial artificial chromosome (BAC) transgenic mice expressing a reporter protein under the control of the genomic elements of the Chat gene (Chat-BAC mice) have facilitated studies of cholinergic neurons. Such mice show robust and faithful expression of the reporter proteins in all known cholinergic cell populations. The availability of the Chat-BAC mice re-ignited interest in hippocampal cholinergic interneurons, because a small number of such reporter-expressing cells is frequently observed in the hippocampus of these mice. However, to date, attempts to confirm that these neurons co-express the endogenous cholinergic marker ChAT, or release ACh, have been unsuccessful. Without such confirmatory evidence it is best to conclude that there are no cholinergic neurons in the hippocampus. Similar considerations apply to other BAC transgenic lines, whose utility as a discovery tool for cell populations heretofore not known to express the genes of interest encoded by the BACs, must be validated by methods that detect expression of the endogenous genes.
Collapse
Affiliation(s)
- Jan Krzysztof Blusztajn
- Department of Pathology and Laboratory Medicine, Boston University School of Medicine Boston, MA, USA
| | - Jasmine Rinnofner
- Department of Applied Life Sciences, University of Applied Sciences Vienna, Austria
| |
Collapse
|
8
|
Abstract
New neuron addition via continued neurogenesis in the postnatal/adult mammalian brain presents a distinct form of nervous system plasticity. During embryonic development, precise temporal and spatial patterns of neurogenesis are necessary to create the nervous system architecture. Similar between embryonic and postnatal stages, neurogenic proliferation is regulated by neural stem cell (NSC)-intrinsic mechanisms layered upon cues from their local microenvironmental niche. Following developmental assembly, it remains relatively unclear what may be the key driving forces that sustain continued production of neurons in the postnatal/adult brain. Recent experimental evidence suggests that patterned activity from specific neural circuits can also directly govern postnatal/adult neurogenesis. Here, we review experimental findings that revealed cholinergic modulation, and how patterns of neuronal activity and acetylcholine release may differentially or synergistically activate downstream signaling in NSCs. Higher-order excitatory and inhibitory inputs regulating cholinergic neuron firing, and their implications in neurogenesis control are also considered.
Collapse
Affiliation(s)
- Brent Asrican
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | | | - Joshua Erb
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA; Neurobiology Graduate Training Program, Duke University School of Medicine, Durham, NC 27710, USA
| | - Chay T Kuo
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA; Neurobiology Graduate Training Program, Duke University School of Medicine, Durham, NC 27710, USA; Brumley Neonatal Perinatal Research Institute, Duke University School of Medicine, Durham, NC 27710, USA; Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA; Preston Robert Tisch Brain Tumor Center, Duke University School of Medicine, Durham, NC 27710, USA; Duke Institute for Brain Sciences, Duke University School of Medicine, Durham, NC 27710, USA
| |
Collapse
|
9
|
Martínez-Mármol R, Comes N, Styrczewska K, Pérez-Verdaguer M, Vicente R, Pujadas L, Soriano E, Sorkin A, Felipe A. Unconventional EGF-induced ERK1/2-mediated Kv1.3 endocytosis. Cell Mol Life Sci 2015; 73:1515-28. [PMID: 26542799 DOI: 10.1007/s00018-015-2082-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 10/14/2015] [Accepted: 10/26/2015] [Indexed: 12/13/2022]
Abstract
The potassium channel Kv1.3 plays roles in immunity, neuronal development and sensory discrimination. Regulation of Kv1.3 by kinase signaling has been studied. In this context, EGF binds to specific receptors (EGFR) and triggers tyrosine kinase-dependent signaling, which down-regulates Kv1.3 currents. We show that Kv1.3 undergoes EGF-dependent endocytosis. This EGF-mediated mechanism is relevant because is involved in adult neural stem cell fate determination. We demonstrated that changes in Kv1.3 subcellular distribution upon EGFR activation were due to Kv1.3 clathrin-dependent endocytosis, which targets the Kv1.3 channels to the lysosomal degradative pathway. Interestingly, our results further revealed that relevant tyrosines and other interacting motifs, such as PDZ and SH3 domains, were not involved in the EGF-dependent Kv1.3 internalization. However, a new, and yet undescribed mechanism, of ERK1/2-mediated threonine phosphorylation is crucial for the EGF-mediated Kv1.3 endocytosis. Our results demonstrate that EGF triggers the down-regulation of Kv1.3 activity and its expression at the cell surface, which is important for the development and migration of adult neural progenitors.
Collapse
Affiliation(s)
- Ramón Martínez-Mármol
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina (IBUB), Barcelona, Spain.,Departament de Biologia Celular, Universitat de Barcelona, Barcelona, Spain
| | - Núria Comes
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina (IBUB), Barcelona, Spain
| | - Katarzyna Styrczewska
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina (IBUB), Barcelona, Spain
| | - Mireia Pérez-Verdaguer
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina (IBUB), Barcelona, Spain
| | - Rubén Vicente
- Laboratory of Molecular Physiology and Channelopathies, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, Barcelona, Spain
| | - Lluís Pujadas
- Departament de Biologia Celular, Universitat de Barcelona, Barcelona, Spain
| | - Eduardo Soriano
- Departament de Biologia Celular, Universitat de Barcelona, Barcelona, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain.,Vall d´Hebron Institute of Research (VHIR) and Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Alexander Sorkin
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Antonio Felipe
- Molecular Physiology Laboratory, Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina (IBUB), Barcelona, Spain. .,Departament de Bioquímica i Biologia Molecular, Universitat de Barcelona, Avda. Diagonal 643, 08028, Barcelona, Spain.
| |
Collapse
|
10
|
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.
Collapse
Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano (TO), and Department of Veterinary Morphophysiology, University of Turin, Turin, Italy.
| | | |
Collapse
|
11
|
Bribián A, Fontana X, Llorens F, Gavín R, Reina M, García-Verdugo JM, Torres JM, de Castro F, del Río JA. Role of the cellular prion protein in oligodendrocyte precursor cell proliferation and differentiation in the developing and adult mouse CNS. PLoS One 2012; 7:e33872. [PMID: 22529900 PMCID: PMC3329524 DOI: 10.1371/journal.pone.0033872] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Accepted: 02/18/2012] [Indexed: 11/18/2022] Open
Abstract
There are numerous studies describing the signaling mechanisms that mediate oligodendrocyte precursor cell (OPC) proliferation and differentiation, although the contribution of the cellular prion protein (PrPc) to this process remains unclear. PrPc is a glycosyl-phosphatidylinositol (GPI)-anchored glycoprotein involved in diverse cellular processes during the development and maturation of the mammalian central nervous system (CNS). Here we describe how PrPc influences oligodendrocyte proliferation in the developing and adult CNS. OPCs that lack PrPc proliferate more vigorously at the expense of a delay in differentiation, which correlates with changes in the expression of oligodendrocyte lineage markers. In addition, numerous NG2-positive cells were observed in cortical regions of adult PrPc knockout mice, although no significant changes in myelination can be seen, probably due to the death of surplus cells.
Collapse
Affiliation(s)
- Ana Bribián
- Molecular and Cellular Neurobiotechnology, Catalonian Institute for Bioengineering (IBEC), Parc Científic de Barcelona, Barcelona, Spain
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Xavier Fontana
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
| | - Franc Llorens
- Molecular and Cellular Neurobiotechnology, Catalonian Institute for Bioengineering (IBEC), Parc Científic de Barcelona, Barcelona, Spain
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Rosalina Gavín
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - Manuel Reina
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
| | - José Manuel García-Verdugo
- Laboratorio de Neurobiología Comparada, Instituto Cabanillas de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Valencia, Spain
| | - Juan María Torres
- Centro de Investigación en Sanidad Animal (CISA-INIA), Madrid, Spain
| | - Fernando de Castro
- GNDe-Grupo de Neurobiología del Desarrollo, Unidad de Neurología Experimental, Hospital Nacional de Parapléjicos, Toledo, Spain
- Instituto Cajal-CSIC, Madrid, Spain
| | - José Antonio del Río
- Molecular and Cellular Neurobiotechnology, Catalonian Institute for Bioengineering (IBEC), Parc Científic de Barcelona, Barcelona, Spain
- Department of Cell Biology, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
- * E-mail:
| |
Collapse
|
12
|
Olfactory bulbectomy, but not odor conditioned aversion, induces the differentiation of immature neurons in the adult rat piriform cortex. Neuroscience 2011; 181:18-27. [DOI: 10.1016/j.neuroscience.2011.03.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/28/2011] [Accepted: 03/01/2011] [Indexed: 01/11/2023]
|
13
|
Keiner S, Walter J, Oberland J, Redecker C. Contribution of constitutively proliferating precursor cell subtypes to dentate neurogenesis after cortical infarcts. BMC Neurosci 2010; 11:146. [PMID: 21083887 PMCID: PMC2993721 DOI: 10.1186/1471-2202-11-146] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 11/17/2010] [Indexed: 11/29/2022] Open
Abstract
Background It is well known that focal ischemia increases neurogenesis in the adult dentate gyrus of the hippocampal formation but the cellular mechanisms underlying this proliferative response are only poorly understood. We here investigated whether precursor cells which constitutively proliferate before the ischemic infarct contribute to post-ischemic neurogenesis. To this purpose, transgenic mice expressing green fluorescent protein (GFP) under the control of the nestin promoter received repetitive injections of the proliferation marker bromodeoxyuridine (BrdU) prior to induction of cortical infarcts. We then immunocytochemically analyzed the fate of these BrdU-positive precursor cell subtypes from day 4 to day 28 after the lesion. Results Quantification of BrdU-expressing precursor cell populations revealed no alteration in number of radial glia-like type 1 cells but a sequential increase of later precursor cell subtypes in lesioned animals (type 2a cells at day 7, type 3 cells/immature neurons at day 14). These alterations result in an enhanced survival of mature neurons 4 weeks postinfarct. Conclusions Focal cortical infarcts recruit dentate precursor cells generated already before the infarct and significantly contribute to an enhanced neurogenesis. Our findings thereby increase our understanding of the complex cellular mechanisms of postlesional neurogenesis.
Collapse
Affiliation(s)
- Silke Keiner
- Hans-Berger-Clinic for Neurology, University Hospital Jena, Erlanger Allee 101, Jena, Germany
| | | | | | | |
Collapse
|
14
|
Madroñal N, López-Aracil C, Rangel A, del Río JA, Delgado-García JM, Gruart A. Effects of enriched physical and social environments on motor performance, associative learning, and hippocampal neurogenesis in mice. PLoS One 2010; 5:e11130. [PMID: 20559565 PMCID: PMC2886110 DOI: 10.1371/journal.pone.0011130] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2010] [Accepted: 05/20/2010] [Indexed: 12/18/2022] Open
Abstract
We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice.
Collapse
Affiliation(s)
- Noelia Madroñal
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain
| | | | - Alejandra Rangel
- Molecular and Cellular Neurobiotechnology, Catalonian Institute of Bioengineering and Department of Cell Biology, University of Barcelona and Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | - José A. del Río
- Molecular and Cellular Neurobiotechnology, Catalonian Institute of Bioengineering and Department of Cell Biology, University of Barcelona and Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Barcelona, Spain
| | | | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain
- * E-mail:
| |
Collapse
|
15
|
Shetty AK, Hattiangady B, Rao MS, Shuai B. Deafferentation enhances neurogenesis in the young and middle aged hippocampus but not in the aged hippocampus. Hippocampus 2010; 21:631-46. [PMID: 20333732 DOI: 10.1002/hipo.20776] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2010] [Indexed: 12/13/2022]
Abstract
Increased neurogenesis in the dentate gyrus (DG) after brain insults such as excitotoxic lesions, seizures, or stroke is a well known phenomenon in the young hippocampus. This plasticity reflects an innate compensatory response of neural stem cells (NSCs) in the young hippocampus to preserve function or minimize damage after injury. However, injuries to the middle-aged and aged hippocampi elicit either no or dampened neurogenesis response, which could be due to an altered plasticity of NSCs and/or the hippocampus with age. We examined whether the plasticity of NSCs to increase neurogenesis in response to a milder injury such as partial deafferentation is preserved during aging. We quantified DG neurogenesis in the hippocampus of young, middle-aged, and aged F344 rats after partial deafferentation. A partial deafferentation of the left hippocampus without any apparent cell loss was induced via administration of Kainic acid (0.5 μg in 1.0 μl) into the right lateral ventricle of the brain. In this model, degeneration of CA3 pyramidal neurons and dentate hilar neurons in the right hippocampus results in loss of commissural axons which leads to partial deafferentation of the dendrites of dentate granule cells and CA1-CA3 pyramidal neurons in the left hippocampus. Quantification of newly born cells that are added to the dentate granule cell layer at postdeafferentation days 4-15 using 5'-bromodeoxyuridine (BrdU) labeling revealed greatly increased addition of newly born cells (∼three fold increase) in the deafferented young and middle-aged hippocampi but not in the deafferented aged hippocampus. Measurement of newly born neurons using doublecortin (DCX) immunostaining also revealed similar findings. Analyses using BrdU-DCX dual immunofluorescence demonstrated no changes in neuronal fate-choice decision of newly born cells after deafferentation, in comparison to the age-matched naive hippocampus in all age groups. Thus, the plasticity of hippocampal NSCs to increase DG neurogenesis in response to a milder injury such as partial hippocampal deafferentation is preserved until middle age but lost at old age.
Collapse
Affiliation(s)
- Ashok K Shetty
- Medical Research and Surgery Services, Veterans Affairs Medical Center, Durham, North Carolina, USA.
| | | | | | | |
Collapse
|
16
|
Ho NF, Han SP, Dawe GS. Effect of voluntary running on adult hippocampal neurogenesis in cholinergic lesioned mice. BMC Neurosci 2009; 10:57. [PMID: 19500352 PMCID: PMC2711090 DOI: 10.1186/1471-2202-10-57] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 06/05/2009] [Indexed: 11/10/2022] Open
Abstract
Background Cholinergic neuronal dysfunction of the basal forebrain is observed in patients with Alzheimer's disease and dementia, and has been linked to decreased neurogenesis in the hippocampus, a region involved in learning and memory. Running is a robust inducer of adult hippocampal neurogenesis. This study aims to address the effect of running on hippocampal neurogenesis in lesioned mice, where septohippocampal cholinergic neurones have been selectively eliminated in the medial septum and diagonal band of Broca of the basal forebrain by infusion of mu-p75-saporin immunotoxin. Results Running increased the number of newborn cells in the dentate gyrus of the hippocampus in cholinergic denervated mice compared to non-lesioned mice 24 hours after injection of bromodeoxyuridine (BrdU). Although similar levels of surviving cells were present in cholinergic depleted animals and their respective controls four weeks after injection of BrdU, the majority of progenitors that proliferate in response to the initial period of running were not able to survive beyond one month without cholinergic input. Despite this, the running-induced increase in the number of surviving neurones was not affected by cholinergic depletion. Conclusion The lesion paradigm used here models aspects of the cholinergic deficits associated with Alzheimer's Disease and aging. We showed that running still increased the number of newborn cells in the adult hippocampal dentate gyrus in this model of neurodegenerative disease.
Collapse
Affiliation(s)
- New Fei Ho
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Centre for Life Sciences (CeLS), Level 4, 28 Medical Drive, 117456, Singapore.
| | | | | |
Collapse
|
17
|
Mitochondrial fragmentation is involved in methamphetamine-induced cell death in rat hippocampal neural progenitor cells. PLoS One 2009; 4:e5546. [PMID: 19436752 PMCID: PMC2677674 DOI: 10.1371/journal.pone.0005546] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 04/19/2009] [Indexed: 12/28/2022] Open
Abstract
Methamphetamine (METH) induces neurodegeneration through damage and apoptosis of dopaminergic nerve terminals and striatal cells, presumably via cross-talk between the endoplasmic reticulum and mitochondria-dependent death cascades. However, the effects of METH on neural progenitor cells (NPC), an important reservoir for replacing neurons and glia during development and injury, remain elusive. Using a rat hippocampal NPC (rhNPC) culture, we characterized the METH-induced mitochondrial fragmentation, apoptosis, and its related signaling mechanism through immunocytochemistry, flow cytometry, and Western blotting. We observed that METH induced rhNPC mitochondrial fragmentation, apoptosis, and inhibited cell proliferation. The mitochondrial fission protein dynamin-related protein 1 (Drp1) and reactive oxygen species (ROS), but not calcium (Ca2+) influx, were involved in the regulation of METH-induced mitochondrial fragmentation. Furthermore, our results indicated that dysregulation of ROS contributed to the oligomerization and translocation of Drp1, resulting in mitochondrial fragmentation in rhNPC. Taken together, our data demonstrate that METH-mediated ROS generation results in the dysregulation of Drp1, which leads to mitochondrial fragmentation and subsequent apoptosis in rhNPC. This provides a potential mechanism for METH-related neurodegenerative disorders, and also provides insight into therapeutic strategies for the neurodegenerative effects of METH.
Collapse
|
18
|
Abstract
Whereas adult neurogenesis appears to be a universal phenomenon in the vertebrate brain, enormous differences exist in neurogenic potential between "lower" and "higher" vertebrates. Studies in the gymnotiform fish Apteronotus leptorhynchus and in zebrafish have indicated that the relative number of new cells, as well as the number of neurogenic sites, are at least one, if not two, orders of magnitude larger in teleosts than in mammals. In teleosts, these neurogenic sites include brain regions homologous to the mammalian hippocampus and olfactory bulb, both of which have consistently exhibited neurogenesis in all species examined thus far. The source of the new cells in the teleostean brain are intrinsic stem cells that give rise to both glial cells and neurons. In several brain regions, the young cells migrate, guided by radial glial fibers, to specific target areas where they integrate into existing neural networks. Approximately half of the new cells survive for the rest of the fish's life, whereas the other half are eliminated through apoptotic cell death. A potential mechanism regulating development of the new cells is provided by somatic genomic alterations. The generation of new cells, together with elimination of damaged cells through apoptosis, also enables teleost fish rapid and efficient neuronal regeneration after brain injuries. Proteome analysis has identified a number of proteins potentially involved in the individual regenerative processes. Comparative analysis has suggested that differences between teleosts and mammals in the growth of muscles and sensory organs are key to explain the differences in adult neurogenesis that evolved during phylogenetic development of the two taxa.
Collapse
Affiliation(s)
- Günther K H Zupanc
- School of Engineering and Science, Jacobs University Bremen, Bremen, Germany.
| |
Collapse
|
19
|
Riquelme PA, Drapeau E, Doetsch F. Brain micro-ecologies: neural stem cell niches in the adult mammalian brain. Philos Trans R Soc Lond B Biol Sci 2008; 363:123-37. [PMID: 17322003 PMCID: PMC2605490 DOI: 10.1098/rstb.2006.2016] [Citation(s) in RCA: 195] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Neurogenesis persists in two germinal regions in the adult mammalian brain, the subventricular zone of the lateral ventricles and the subgranular zone in the hippocampal formation. Within these two neurogenic niches, specialized astrocytes are neural stem cells, capable of self-renewing and generating neurons and glia. Cues within the niche, from cell-cell interactions to diffusible factors, are spatially and temporally coordinated to regulate proliferation and neurogenesis, ultimately affecting stem cell fate choices. Here, we review the components of adult neural stem cell niches and how they act to regulate neurogenesis in these regions.
Collapse
Affiliation(s)
- Patricio A Riquelme
- Center for Neurobiology and Behavior, Columbia University630 West 168th Street, New York City, NY 10032, USA
| | - Elodie Drapeau
- Department of Pathology, Columbia University630 West 168th Street, New York City, NY 10032, USA
| | - Fiona Doetsch
- Center for Neurobiology and Behavior, Columbia University630 West 168th Street, New York City, NY 10032, USA
- Department of Pathology, Columbia University630 West 168th Street, New York City, NY 10032, USA
- Department of Neurology, Columbia University630 West 168th Street, New York City, NY 10032, USA
- Author for correspondence ()
| |
Collapse
|
20
|
Gómez-Climent MA, Castillo-Gómez E, Varea E, Guirado R, Blasco-Ibáñez JM, Crespo C, Martínez-Guijarro FJ, Nácher J. A population of prenatally generated cells in the rat paleocortex maintains an immature neuronal phenotype into adulthood. ACTA ACUST UNITED AC 2008; 18:2229-40. [PMID: 18245040 DOI: 10.1093/cercor/bhm255] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
New neurons in the adult brain transiently express molecules related to neuronal development, such as the polysialylated form of neural cell adhesion molecule, or doublecortin (DCX). These molecules are also expressed by a cell population in the rat paleocortex layer II, whose origin, phenotype, and function are not clearly understood. We have classified most of these cells as a new cell type termed tangled cell. Some cells with the morphology of semilunar-pyramidal transitional neurons were also found among this population, as well as some scarce cells resembling semilunar, pyramidal. and fusiform neurons. We have found that none of these cells in layer II express markers of glial cells, mature, inhibitory, or principal neurons. They appear to be in a prolonged immature state, confirmed by the coexpression of DCX, TOAD/Ulip/CRMP-4, A3 subunit of the cyclic nucleotide-gated channel, or phosphorylated cyclic adenosine monophosphate response element-binding protein. Moreover, most of them lack synaptic contacts, are covered by astroglial lamellae, and fail to express cellular activity markers, such as c-Fos or Arc, and N-methyl-d-aspartate or glucocorticoid receptors. We have found that none of these cells appear to be generated during adulthood or early youth and that most of them have been generated during embryonic development, mainly in E15.5.
Collapse
Affiliation(s)
- María Angeles Gómez-Climent
- Neurobiology Unit and Program in Basic and Applied Neurosciences, Cell Biology Dpt., Universitat de València, Spain
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Naujokat C, Sarić T. Concise Review: Role and Function of the Ubiquitin-Proteasome System in Mammalian Stem and Progenitor Cells. Stem Cells 2007; 25:2408-18. [PMID: 17641241 DOI: 10.1634/stemcells.2007-0255] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Highly ordered degradation of cell proteins by the ubiquitin-proteasome system, a sophisticated cellular proteolytic machinery, has been identified as a key regulatory mechanism in many eukaryotic cells. Accumulating evidence reveals that the ubiquitin-proteasome system is involved in the regulation of fundamental processes in mammalian stem and progenitor cells of embryonic, neural, hematopoietic, and mesenchymal origin. Such processes, including development, survival, differentiation, lineage commitment, migration, and homing, are directly controlled by the ubiquitin-proteasome system, either via proteolytic degradation of key regulatory proteins of signaling and gene expression pathways or via nonproteolytic mechanisms involving the proteasome itself or posttranslational modifications of target proteins by ubiquitin or other ubiquitin-like modifiers. Future characterization of the precise roles and functions of the ubiquitin-proteasome system in mammalian stem and early progenitor cells will improve our understanding of stem cell biology and may provide an experimental basis for the development of novel therapeutic strategies in regenerative medicine. Disclosure of potential conflicts of interest is found at the end of this article.
Collapse
Affiliation(s)
- Cord Naujokat
- Institute of Immunology, University of Heidelberg, Im Neuenheimer Feld 305, D-69120 Heidelberg, Germany.
| | | |
Collapse
|
22
|
Liu Z, Fan Y, Won SJ, Neumann M, Hu D, Zhou L, Weinstein PR, Liu J. Chronic treatment with minocycline preserves adult new neurons and reduces functional impairment after focal cerebral ischemia. Stroke 2006; 38:146-52. [PMID: 17122429 DOI: 10.1161/01.str.0000251791.64910.cd] [Citation(s) in RCA: 225] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND AND PURPOSE Evidence suggests that activated microglia are detrimental to the survival of new hippocampal neurons, whereas blocking inflammation has been shown to restore hippocampal neurogenesis after cranial irradiation and seizure. The aim of this current study is to determine the effect of minocycline on neurogenesis and functional recovery after cerebral focal ischemia. METHODS Four days after temporary middle cerebral artery occlusion, minocycline was administered intraperitoneally for 4 weeks. BrdU was given on days 4 to 7 after middle cerebral artery occlusion to track cell proliferation. The number of remaining new neurons and activated microglia were quantified in the dentate gyrus. Infarct volume was measured to assess the treatment effect of minocycline. Motor and cognitive functions were evaluated 6 weeks after middle cerebral artery occlusion. RESULTS Minocycline delivered 4 days after middle cerebral artery occlusion for 4 weeks did not result in reduction in infarct size but significantly decreased the number of activated microglia in the dentate gyrus. Minocycline also significantly increased the number of newborn neurons that coexpressing BrdU and NeuN without significantly affecting progenitor cell proliferation in the dentate gyrus. Lastly, minocycline significantly improved motor coordination on the rotor rod, reduced the preferential use of the unaffected limb during exploration, reduced the frequency of footfalls in the affected limb when traversing on a horizontal ladder, and improved spatial learning and memory in the water maze test. CONCLUSIONS Minocycline reduces functional impairment caused by cerebral focal ischemia. The improved function is associated with enhanced neurogenesis and reduced microglia activation in the dentate gyrus and possibly improved neural environment after chronic treatment with minocycline.
Collapse
Affiliation(s)
- Zhengyan Liu
- Department of Neurological Surgery, University of California-San Francisco, San Francisco, CA 94121, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Ge S, Pradhan DA, Ming GL, Song H. GABA sets the tempo for activity-dependent adult neurogenesis. Trends Neurosci 2006; 30:1-8. [PMID: 17116335 DOI: 10.1016/j.tins.2006.11.001] [Citation(s) in RCA: 242] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 08/22/2006] [Accepted: 11/10/2006] [Indexed: 02/05/2023]
Abstract
GABA, a major inhibitory neurotransmitter in the adult brain, activates synaptic and extrasynaptic GABA(A) receptors, causing hyperpolarization of mature neurons. As in the embryonic nervous system, GABA depolarizes neural progenitors and immature neurons in the adult brain. Several recent studies have suggested that GABA has crucial roles in regulating different steps of adult neurogenesis, including proliferation of neural progenitors, migration and differentiation of neuroblasts, and synaptic integration of newborn neurons. Here, we review recent findings on how GABA regulates adult neurogenesis in the subventricular zone of the lateral ventricles and in the dentate gyrus of the hippocampus. We also discuss an emerging view that GABA serves as a key mediator of neuronal activity in setting the tempo of adult neurogenesis.
Collapse
Affiliation(s)
- Shaoyu Ge
- Institute for Cell Engineering, Department of Neurology, Johns Hopkins University School of Medicine, 733 North Broadway, BRB 735, Baltimore, MD 21205, USA
| | | | | | | |
Collapse
|