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Arellano JI, Rakic P. Modelling adult neurogenesis in the aging rodent hippocampus: a midlife crisis. Front Neurosci 2024; 18:1416460. [PMID: 38887368 PMCID: PMC11181911 DOI: 10.3389/fnins.2024.1416460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Contrary to humans, adult hippocampal neurogenesis in rodents is not controversial. And in the last three decades, multiple studies in rodents have deemed adult neurogenesis essential for most hippocampal functions. The functional relevance of new neurons relies on their distinct physiological properties during their maturation before they become indistinguishable from mature granule cells. Most functional studies have used very young animals with robust neurogenesis. However, this trait declines dramatically with age, questioning its functional relevance in aging animals, a caveat that has been mentioned repeatedly, but rarely analyzed quantitatively. In this meta-analysis, we use data from published studies to determine the critical functional window of new neurons and to model their numbers across age in both mice and rats. Our model shows that new neurons with distinct functional profile represent about 3% of the total granule cells in young adult 3-month-old rodents, and their number decline following a power function to reach less than 1% in middle aged animals and less than 0.5% in old mice and rats. These low ratios pose an important logical and computational caveat to the proposed essential role of new neurons in the dentate gyrus, particularly in middle aged and old animals, a factor that needs to be adequately addressed when defining the relevance of adult neurogenesis in hippocampal function.
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Affiliation(s)
- Jon I Arellano
- Department of Neuroscience, Yale University, New Haven, CT, United States
| | - Pasko Rakic
- Department of Neuroscience, Yale University, New Haven, CT, United States
- Kavli Institute for Neuroscience at Yale, Yale University, New Haven, CT, United States
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2
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康 赟, 唐 东, 张 健, 夏 青. [Validation of a C57/BL6J mouse model of focal cerebral ischemia established by electrocoagulation of the middle cerebral artery]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2024; 44:100-107. [PMID: 38293981 PMCID: PMC10878904 DOI: 10.12122/j.issn.1673-4254.2024.01.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Indexed: 02/01/2024]
Abstract
OBJECTIVE To modify the method for establishing mouse models of middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia using electrocoagulation. METHODS Forty-six C57/BL6J male mice were divided into MCAO model group (n=34) and sham-operated group (n=12). In the model group, MCAO was induced by permanent coagulation of the right middle cerebral artery (MCA) using a coagulator, and cerebral blood flow perfusion was monitored before and at 20 min and 1 day after modeling. Neurological deficits of the mice at 1, 7, and 14 days after modeling were evaluated using Longa score, mNSS score, beam walking test, cylinder test and corner test. TTC staining was used to measure the cerebral infarct size, and Western blotting was performed to detect the expressions of BDNF, GFAP and DCX proteins in the ischemic cortex. RESULTS The mice in the model group showed significantly reduced cerebral blood flow in the MCA on the ischemic side and obvious neurological deficits with increased forelimb use asymmetry on days 1, 7 and 14 after modeling (P < 0.05). In the cerebral cortex on the ischemic side of the model mice, the expressions of GFAP and DCX increased significantly at 1, 7, and 14 days (P < 0.05) and the expression of BDNF increased at 1 day after modeling ischemia (P < 0.05). CONCLUSION We successfully prepared mouse models of MCAO using a modified method by changing the electrocoagulation location from the distal location of the junction between the MCA and the inferior cerebral vein to a 2 mm segment medial to the junction between the MCA and the olfactory bundle.
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Affiliation(s)
- 赟赟 康
- 天津中医药大学实验针灸学研究中心,天津 301617Research Center of Experimental Acupuncture, Tianjin University of Chinese Medicine, Tianjin 301617, China
| | - 东宁 唐
- 天津中医药大学实验针灸学研究中心,天津 301617Research Center of Experimental Acupuncture, Tianjin University of Chinese Medicine, Tianjin 301617, China
| | - 健 张
- 天津中医药大学实验针灸学研究中心,天津 301617Research Center of Experimental Acupuncture, Tianjin University of Chinese Medicine, Tianjin 301617, China
- 天津中医药大学医学技术学院,天津 301617School of Medical Technology, Tianjin University of Chinese Medicine, Tianjin 301617, China
| | - 青 夏
- 天津中医药大学实验针灸学研究中心,天津 301617Research Center of Experimental Acupuncture, Tianjin University of Chinese Medicine, Tianjin 301617, China
- 天津中医药大学医学技术学院,天津 301617School of Medical Technology, Tianjin University of Chinese Medicine, Tianjin 301617, China
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Latchney SE, Ruiz Lopez BR, Womble PD, Blandin KJ, Lugo JN. Neuronal deletion of phosphatase and tensin homolog in mice results in spatial dysregulation of adult hippocampal neurogenesis. Front Mol Neurosci 2023; 16:1308066. [PMID: 38130682 PMCID: PMC10733516 DOI: 10.3389/fnmol.2023.1308066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
Adult neurogenesis is a persistent phenomenon in mammals that occurs in select brain structures in both healthy and diseased brains. The tumor suppressor gene, phosphatase and tensin homolog deleted on chromosome 10 (Pten) has previously been found to restrict the proliferation of neural stem/progenitor cells (NSPCs) in vivo. In this study, we aimed to provide a comprehensive picture of how conditional deletion of Pten may regulate the genesis of adult NSPCs in the dentate gyrus of the hippocampus and the subventricular zone bordering the lateral ventricles. Using conventional markers and stereology, we quantified multiple stages of neurogenesis, including proliferating cells, immature neurons (neuroblasts), and apoptotic cells in several regions of the dentate gyrus, including the subgranular zone (SGZ), outer granule cell layer (oGCL), molecular layer, and hilus at 4 and 10 weeks of age. Our data demonstrate that conditional deletion of Pten in mice produces successive increases in dentate gyrus proliferating cells and immature neuroblasts, which confirms the known negative roles Pten has on cell proliferation and maturation. Specifically, we observe a significant increase in Ki67+ proliferating cells in the neurogenic SGZ at 4 weeks of age, but not 10 weeks of age. We also observe a delayed increase in neuroblasts at 10 weeks of age. However, our study expands on previous work by providing temporal, subregional, and neurogenesis-stage resolution. Specifically, we found that Pten deletion initially increases cell proliferation in the neurogenic SGZ, but this increase spreads to non-neurogenic dentate gyrus areas, including the hilus, oGCL, and molecular layer, as mice age. We also observed region-specific increases in apoptotic cells in the dentate gyrus hilar region that paralleled the regional increases in Ki67+ cells. Our work is accordant with the literature showing that Pten serves as a negative regulator of dentate gyrus neurogenesis but adds temporal and spatial components to the existing knowledge.
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Affiliation(s)
- Sarah E. Latchney
- Department of Biology, St. Mary’s College of Maryland, St. Mary’s City, MD, United States
| | - Brayan R. Ruiz Lopez
- Department of Biology, St. Mary’s College of Maryland, St. Mary’s City, MD, United States
| | - Paige D. Womble
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Katherine J. Blandin
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
| | - Joaquin N. Lugo
- Department of Psychology and Neuroscience, Baylor University, Waco, TX, United States
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4
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Kim Y, Kim S, Ho WK, Lee SH. Burst firing is required for induction of Hebbian LTP at lateral perforant path to hippocampal granule cell synapses. Mol Brain 2023; 16:45. [PMID: 37217996 DOI: 10.1186/s13041-023-01034-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/04/2023] [Indexed: 05/24/2023] Open
Abstract
High frequency burst firing is critical in summation of back-propagating action potentials (APs) in dendrites, which may greatly depolarize dendritic membrane potential. The physiological significance of burst firings of hippocampal dentate GCs in synaptic plasticity remains unknown. We found that GCs with low input resistance could be categorized into regular-spiking (RS) and burst-spiking (BS) cells based on their initial firing frequency (Finit) upon somatic rheobase current injection, and investigated how two types of GCs differ in long-term potentiation (LTP) induced by high-frequency lateral perforant pathway (LPP) inputs. Induction of Hebbian LTP at LPP synapses required at least three postsynaptic APs at Finit higher than 100 Hz, which was met in BS but not in RS cells. The synaptically evoked burst firing was critically dependent on persistent Na+ current, which was larger in BS than RS cells. The Ca2+ source for Hebbian LTP at LPP synapses was primarily provided by L-type calcium channels. In contrast, Hebbian LTP at medial PP synapses was mediated by T-type calcium channels, and could be induced regardless of cell types or Finit of postsynaptic APs. These results suggest that intrinsic firing properties affect synaptically driven firing patterns, and that bursting behavior differentially affects Hebbian LTP mechanisms depending on the synaptic input pathway.
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Affiliation(s)
- Yoonsub Kim
- Cell Physiology Lab. Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Sooyun Kim
- Clinical Research Institute, Seoul National University Hospital, Seoul, Republic of Korea
| | - Won-Kyung Ho
- Cell Physiology Lab. Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Suk-Ho Lee
- Cell Physiology Lab. Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
- Department of Brain and Cognitive Science, Seoul National University College of Natural Science, 103 Daehak-Ro, Jongno-Gu, 03080, Seoul, Republic of Korea.
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5
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Timalsina B, Haque MN, Choi HJ, Dash R, Moon IS. Thymol in Trachyspermum ammi seed extract exhibits neuroprotection, learning, and memory enhancement in scopolamine-induced Alzheimer's disease mouse model. Phytother Res 2023. [PMID: 36808768 DOI: 10.1002/ptr.7777] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/18/2022] [Accepted: 01/29/2023] [Indexed: 02/22/2023]
Abstract
Several reports have stated the neuroprotective and learning/memory effects of Tachyspermum ammi seed extract (TASE) and its principal component thymol; however, little is known about its underlying molecular mechanisms and neurogenesis potential. This study aimed to provide insights into TASE and a thymol-mediated multifactorial therapeutic approach in a scopolamine-induced Alzheimer's disease (AD) mouse model. TASE and thymol supplementation significantly reduced oxidative stress markers such as brain glutathione, hydrogen peroxide, and malondialdehyde in mouse whole brain homogenates. Tumor necrosis factor-alpha was significantly downregulated, whereas the elevation of brain-derived neurotrophic factor and phospho-glycogen synthase kinase-3 beta (serine 9) enhanced learning and memory in the TASE- and thymol-treated groups. A significant reduction in the accumulation of Aβ 1-42 peptides was observed in the brains of TASE- and thymol-treated mice. Furthermore, TASE and thymol significantly promoted adult neurogenesis, with increased doublecortin positive neurons in the subgranular and polymorphic zones of the dentate gyrus in treated-mice. Collectively, TASE and thymol could potentially act as natural therapeutic agents for the treatment of neurodegenerative disorders, such as AD.
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Affiliation(s)
- Binod Timalsina
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Md Nazmul Haque
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea.,Department of Fisheries Biology and Genetics, Patuakhali Science and Technology University, Patuakhali, Bangladesh
| | - Ho Jin Choi
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Raju Dash
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
| | - Il Soo Moon
- Department of Anatomy, Dongguk University College of Medicine, Gyeongju, Korea
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Kim HI, Lim J, Choi HJ, Kim SH, Choi HJ. ERRγ Ligand Regulates Adult Neurogenesis and Depression-like Behavior in a LRRK2-G2019S-associated Young Female Mouse Model of Parkinson's Disease. Neurotherapeutics 2022; 19:1298-1312. [PMID: 35614294 PMCID: PMC9587185 DOI: 10.1007/s13311-022-01244-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2022] [Indexed: 11/28/2022] Open
Abstract
Adult neurogenesis, a process controlling the proliferation to maturation of newly generated neurons in the post-developmental brain, is associated with various brain functions and pathogenesis of neuropsychological diseases, such as Parkinson's disease (PD) and depression. Because orphan nuclear receptor estrogen-related receptor γ (ERRγ) plays a role in the differentiation of neuronal cells, we investigated whether an ERRγ ligand enhances adult neurogenesis and regulates depressive behavior in a LRRK2-G2019S-associated mouse model of PD. Young female LRRK2-G2019S mice (7-9 weeks old) showed depression-like behavior without dopaminergic neuronal loss in the nigrostriatal pathway nor motor dysfunction. A significant decrease in adult hippocampal neurogenesis was detected in young female LRRK2-G2019S mice, but not in comparable male mice. A synthetic ERRγ ligand, (E)-4-hydroxy-N'-(4-(phenylethynyl)benzylidene)benzohydrazide (HPB2), ameliorated depression-like behavior in young female LRRK2-G2019S mice and enhanced neurogenesis in the hippocampus, as evidenced by increases in the number of bromodeoxyuridine/neuronal nuclei-positive cells and in the intensity and number of doublecortin-positive cells in the hippocampal dentate gyrus (DG). Moreover, HPB2 significantly increased the number of spines and the number and length of dendrites in the DG of young female LRRK2-G2019S mice. Furthermore, HPB2 upregulated brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling, one of the important factors regulating neurogenesis, as well as phosphorylated cAMP-response element binding protein-positive cells in the DG of young female LRRK2-G2019S mice. Together, these results suggest ERRγ as a novel therapeutic target for PD-associated depression by modulating adult neurogenesis and BDNF/TrkB signaling.
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Affiliation(s)
- Hyo In Kim
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, 11160, Republic of Korea
| | - Juhee Lim
- College of Pharmacy, Woosuk University, Wanju-gun, Jeollabuk-do, 55338, Republic of Korea
| | - Hyo-Jung Choi
- Daegu-Gyeongbuk Medical Innovation Foundation, New Drug Development Center, Daegu, 41061, Republic of Korea
| | - Seok-Ho Kim
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, 11160, Republic of Korea.
| | - Hyun Jin Choi
- College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon, Gyeonggi-do, 11160, Republic of Korea.
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Hourigan B, Balay SD, Yee G, Sharma S, Tan Q. Capicua regulates the development of adult-born neurons in the hippocampus. Sci Rep 2021; 11:11725. [PMID: 34083623 PMCID: PMC8175746 DOI: 10.1038/s41598-021-91168-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 05/20/2021] [Indexed: 11/12/2022] Open
Abstract
New neurons continuously arise from neural progenitor cells in the dentate gyrus of the adult hippocampus to support ongoing learning and memory formation. To generate functional adult-born neurons, neural progenitor cells proliferate to expand the precursor cell pool and differentiate into neurons. Newly generated cells then undergo postmitotic maturation to migrate to their final destination and develop elaborate dendritic branching, which allows them to receive input signals. Little is known about factors that regulate neuronal differentiation, migration, and dendrite maturation during adult hippocampal neurogenesis. Here, we show that the transcriptional repressor protein capicua (CIC) exhibits dynamic expression in the adult dentate gyrus. Conditional deletion of Cic from the mouse dentate gyrus compromises the adult neural progenitor cell pool without altering their proliferative potential. We further demonstrate that the loss of Cic impedes neuronal lineage development and disrupts dendritic arborization and migration of adult-born neurons. Our study uncovers a previously unrecognized role of CIC in neurogenesis of the adult dentate gyrus.
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Affiliation(s)
- Brenna Hourigan
- Department of Cell Biology, University of Alberta, Edmonton, T6J 2H7, Canada
| | - Spencer D Balay
- Department of Cell Biology, University of Alberta, Edmonton, T6J 2H7, Canada.,Research Institute of Molecular Pathology, Vienna Biocenter, Campus-Vienna-Biocenter 1, 1030, Vienna, Austria
| | - Graydon Yee
- Department of Cell Biology, University of Alberta, Edmonton, T6J 2H7, Canada
| | - Saloni Sharma
- Department of Cell Biology, University of Alberta, Edmonton, T6J 2H7, Canada
| | - Qiumin Tan
- Department of Cell Biology, University of Alberta, Edmonton, T6J 2H7, Canada.
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8
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Coviello S, Benedetti B, Jakubecova D, Belles M, Klimczak P, Gramuntell Y, Couillard-Despres S, Nacher J. PSA Depletion Induces the Differentiation of Immature Neurons in the Piriform Cortex of Adult Mice. Int J Mol Sci 2021; 22:5733. [PMID: 34072166 PMCID: PMC8198564 DOI: 10.3390/ijms22115733] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Immature neurons are maintained in cortical regions of the adult mammalian brain. In rodents, many of these immature neurons can be identified in the piriform cortex based on their high expression of early neuronal markers, such as doublecortin (DCX) and the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). This molecule plays critical roles in different neurodevelopmental events. Taking advantage of a DCX-CreERT2/Flox-EGFP reporter mice, we investigated the impact of targeted PSA enzymatic depletion in the piriform cortex on the fate of immature neurons. We report here that the removal of PSA accelerated the final development of immature neurons. This was revealed by a higher frequency of NeuN expression, an increase in the number of cells carrying an axon initial segment (AIS), and an increase in the number of dendrites and dendritic spines on the immature neurons. Taken together, our results demonstrated the crucial role of the PSA moiety in the protracted development of immature neurons residing outside of the neurogenic niches. More studies will be required to understand the intrinsic and extrinsic factors affecting PSA-NCAM expression to understand how the brain regulates the incorporation of these immature neurons to the established neuronal circuits of the adult brain.
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Affiliation(s)
- Simona Coviello
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Bruno Benedetti
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Dominika Jakubecova
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
| | - Maria Belles
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Patrycja Klimczak
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Yaiza Gramuntell
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Sebastien Couillard-Despres
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Juan Nacher
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
- Spanish National Network for Research in Mental Health (CIBERSAM), 28029 Madrid, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVA, 46010 Valencia, Spain
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Chou SM, Li KX, Huang MY, Chen C, Lin King YH, Li GG, Zhou W, Teo CF, Jan YN, Jan LY, Yang SB. Kv1.1 channels regulate early postnatal neurogenesis in mouse hippocampus via the TrkB signaling pathway. eLife 2021; 10:e58779. [PMID: 34018923 PMCID: PMC8208815 DOI: 10.7554/elife.58779] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 05/20/2021] [Indexed: 12/20/2022] Open
Abstract
In the postnatal brain, neurogenesis occurs only within a few regions, such as the hippocampal sub-granular zone (SGZ). Postnatal neurogenesis is tightly regulated by factors that balance stem cell renewal with differentiation, and it gives rise to neurons that participate in learning and memory formation. The Kv1.1 channel, a voltage-gated potassium channel, was previously shown to suppress postnatal neurogenesis in the SGZ in a cell-autonomous manner. In this study, we have clarified the physiological and molecular mechanisms underlying Kv1.1-dependent postnatal neurogenesis. First, we discovered that the membrane potential of neural progenitor cells is highly dynamic during development. We further established a multinomial logistic regression model for cell-type classification based on the biophysical characteristics and corresponding cell markers. We found that the loss of Kv1.1 channel activity causes significant depolarization of type 2b neural progenitor cells. This depolarization is associated with increased tropomyosin receptor kinase B (TrkB) signaling and proliferation of neural progenitor cells; suppressing TrkB signaling reduces the extent of postnatal neurogenesis. Thus, our study defines the role of the Kv1.1 potassium channel in regulating the proliferation of postnatal neural progenitor cells in mouse hippocampus.
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Affiliation(s)
- Shu-Min Chou
- Institute of Biomedical Sciences, Academia SinicaTaipeiTaiwan
| | - Ke-Xin Li
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | | | - Chao Chen
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Yuan-Hung Lin King
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
- Neuroscience Graduate Program, University of California, San FranciscoSan FranciscoUnited States
| | | | - Wei Zhou
- Department of Anesthesia and Perioperative Care, University of California, San FranciscoSan FranciscoUnited States
| | - Chin Fen Teo
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Yuh Nung Jan
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Lily Yeh Jan
- Howard Hughes Medical Institute, Departments of Physiology, Biochemistry and Biophysics, University of California, San FranciscoSan FranciscoUnited States
| | - Shi-Bing Yang
- Institute of Biomedical Sciences, Academia SinicaTaipeiTaiwan
- Neuroscience Program of Academia Sinica, Academia SinicaTaipeiTaiwan
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10
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Jiang N, Cupolillo D, Grosjean N, Muller E, Deforges S, Mulle C, Amédée T. Impaired plasticity of intrinsic excitability in the dentate gyrus alters spike transfer in a mouse model of Alzheimer's disease. Neurobiol Dis 2021; 154:105345. [PMID: 33766653 DOI: 10.1016/j.nbd.2021.105345] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by cognitive decline related to deficits in synaptic transmission and plasticity. We report in APP/PS1 mice, a double transgenic mouse model of AD, that females displayed an early burden of Aβ plaques load in the stratum moleculare of the dentate gyrus (DG) together with prominent neuroinflammatory activation of astrocytes and microglia. Robust deficits in hippocampus-dependent memory tasks were observed in APP/PS1 female mice as early as 3 months of age. We then studied the functional properties of the lateral perforant path (LPP) to DG granule cells. Remarkably DG granule cells displayed higher intrinsic excitability in APP/PS1 female mice. We showed that the long term potentiation of population spike amplitude induced by high frequency stimulation (HFS) at LPP-DG granule cells synapse is impaired in APP/PS1 female mice. HFS induced plasticity of intrinsic excitability in DG granule cells without inducing noticeable modification of synaptic strength. Furthermore, the enhanced intrinsic excitability was potentiated to a greater extent in APP/PS1 as compared to control mice following HFS. Our study shows that changes in the intrinsic excitability of DG granule cells in AD contribute to the dysfunctional transfer of information from the entorhinal cortex to the hippocampus.
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Affiliation(s)
- Nan Jiang
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Dario Cupolillo
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Noelle Grosjean
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Emeline Muller
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Séverine Deforges
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Christophe Mulle
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France
| | - Thierry Amédée
- Univ. Bordeaux, CNRS, INSERM, Bordeaux Imaging Center, BIC, UMS 3420, US 4, F-33000 Bordeaux, France.
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11
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Radhakrishnan S, Martin CA, Dhayanithy G, Reddy MS, Rela M, Kalkura SN, Sellathamby S. Hypoxic Preconditioning Induces Neuronal Differentiation of Infrapatellar Fat Pad Stem Cells through Epigenetic Alteration. ACS Chem Neurosci 2021; 12:704-718. [PMID: 33508941 DOI: 10.1021/acschemneuro.0c00728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hypoxia is considered a key factor in cellular differentiation and proliferation, particularly during embryonic development; the process of early neurogenesis also occurs under hypoxic conditions. Apart from these developmental processes, hypoxia preconditioning or mild hypoxic sensitization develops resistance against ischemic stroke in deteriorating tissues. We therefore hypothesized that neurons resulting from hypoxia-regulated neuronal differentiation could be the best choice for treating brain ischemia, which contributes to neurodegeneration. In this study, infrapatellar fat pad (IFP), an adipose tissue present beneath the knee joint, was used as the stem cell source. IFP-derived stem cells (IFPSCs) are totally adherent and are mesenchymal stem cells. The transdifferentiation protocol involved hypoxia preconditioning, the use of hypoxic-conditioned medium, and maintenance in maturation medium with α-lipoic acid. The differentiated cells were characterized using microscopy, reverse transcription PCR, real time PCR, and immunocytochemistry. To evaluate the epigenetic reprogramming of IFPSCs to become neuron-like cells, methylation microarrays were performed. Hypoxia preconditioning stabilized and allowed for the translocation of hypoxia inducible factor 1α into the nucleus and induced achaete-scute homologue 1 and doublecortin expression. Following induction, the resultant cells expressed neuronal markers neuron-specific enolase, neurofilament-light chain, growth associated protein 43, synaptosome associated protein 25, and β-III tubulin. The differentiated neural-lineage cells had functional gene expression pertaining to neurotransmitters, their release, and their receptors. The molecular signaling mechanisms regulated developmental neurogenesis. Furthermore, the in vitro physiological condition regulated neurotransmitter respecification or switching during IFPSC differentiation to neurons. Thus, differentiated neurons were fabricated against the ischemic region to treat neurodegenerative diseases.
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Affiliation(s)
- Subathra Radhakrishnan
- National Foundation for Liver Research, Cell Laboratory, Dr. Rela Institute and Medical Centre, Chennai 600 044, India
- Department of Biomedical Science, Bharathidasan University, Tiruchirappalli 620024, India
| | - Catherine Ann Martin
- National Foundation for Liver Research, Cell Laboratory, Dr. Rela Institute and Medical Centre, Chennai 600 044, India
- Crystal Growth Centre, Anna University, Chennai 600025, India
| | | | - Mettu Srinivas Reddy
- National Foundation for Liver Research, Cell Laboratory, Dr. Rela Institute and Medical Centre, Chennai 600 044, India
| | - Mohamed Rela
- National Foundation for Liver Research, Cell Laboratory, Dr. Rela Institute and Medical Centre, Chennai 600 044, India
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Adult-Born Neurons in the Hippocampus Are Essential for Social Memory Maintenance. eNeuro 2020; 7:ENEURO.0182-20.2020. [PMID: 33060182 PMCID: PMC7768285 DOI: 10.1523/eneuro.0182-20.2020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 08/18/2020] [Accepted: 09/30/2020] [Indexed: 01/02/2023] Open
Abstract
Throughout adulthood, the dentate gyrus continues to produce new granule cells, which integrate into the hippocampal circuitry. New neurons have been linked to several known functions of the hippocampus, including learning and memory, anxiety and stress regulation, and social behavior. We explored whether transgenic reduction of adult-born neurons in mice would impair social memory and the formation of social dominance hierarchies. We used a conditional transgenic mouse strain [thymidine kinase (TK) mice] that selectively reduces adult neurogenesis by treatment with the antiviral drug valganciclovir (VGCV). TK mice treated with VGCV were unable to recognize conspecifics as familiar 24 h after initial exposure. We then explored whether reducing new neurons completely impaired their ability to acquire or retrieve a social memory and found that TK mice treated with VGCV were able to perform at control levels when the time between exposure (acquisition) and reexposure (retrieval) was brief. We next explored whether adult-born neurons are involved in dominance hierarchy formation by analyzing their home cage behavior as well as their performance in the tube test, a social hierarchy test, and did not find any consistent alterations in behavior between control and TK mice treated with VGCV. These data suggest that adult neurogenesis is essential for social memory maintenance, but not for acquisition nor retrieval over a short time frame, with no effect on social dominance hierarchy. Future work is needed to explore whether the influence of new neurons on social memory is mediated through connections with the CA2, an area involved in social recognition.
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Arzua T, Yan Y, Jiang C, Logan S, Allison RL, Wells C, Kumar SN, Schäfer R, Bai X. Modeling alcohol-induced neurotoxicity using human induced pluripotent stem cell-derived three-dimensional cerebral organoids. Transl Psychiatry 2020; 10:347. [PMID: 33051447 PMCID: PMC7553959 DOI: 10.1038/s41398-020-01029-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/11/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023] Open
Abstract
Maternal alcohol exposure during pregnancy can substantially impact the development of the fetus, causing a range of symptoms, known as fetal alcohol spectrum disorders (FASDs), such as cognitive dysfunction and psychiatric disorders, with the pathophysiology and mechanisms largely unknown. Recently developed human cerebral organoids from induced pluripotent stem cells are similar to fetal brains in the aspects of development and structure. These models allow more relevant in vitro systems to be developed for studying FASDs than animal models. Modeling binge drinking using human cerebral organoids, we sought to quantify the downstream toxic effects of alcohol (ethanol) on neural pathology phenotypes and signaling pathways within the organoids. The results revealed that alcohol exposure resulted in unhealthy organoids at cellular, subcellular, bioenergetic metabolism, and gene expression levels. Alcohol induced apoptosis on organoids. The apoptotic effects of alcohol on the organoids depended on the alcohol concentration and varied between cell types. Specifically, neurons were more vulnerable to alcohol-induced apoptosis than astrocytes. The alcohol-treated organoids exhibit ultrastructural changes such as disruption of mitochondria cristae, decreased intensity of mitochondrial matrix, and disorganized cytoskeleton. Alcohol exposure also resulted in mitochondrial dysfunction and metabolic stress in the organoids as evidenced by (1) decreased mitochondrial oxygen consumption rates being linked to basal respiration, ATP production, proton leak, maximal respiration and spare respiratory capacity, and (2) increase of non-mitochondrial respiration in alcohol-treated organoids compared with control groups. Furthermore, we found that alcohol treatment affected the expression of 199 genes out of 17,195 genes analyzed. Bioinformatic analyses showed the association of these dysregulated genes with 37 pathways related to clinically relevant pathologies such as psychiatric disorders, behavior, nervous system development and function, organismal injury and abnormalities, and cellular development. Notably, 187 of these genes are critically involved in neurodevelopment, and/or implicated in nervous system physiology and neurodegeneration. Furthermore, the identified genes are key regulators of multiple pathways linked in networks. This study extends for the first time animal models of binge drinking-related FASDs to a human model, allowing in-depth analyses of neurotoxicity at tissue, cellular, subcellular, metabolism, and gene levels. Hereby, we provide novel insights into alcohol-induced pathologic phenotypes, cell type-specific vulnerability, and affected signaling pathways and molecular networks, that can contribute to a better understanding of the developmental neurotoxic effects of binge drinking during pregnancy.
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Affiliation(s)
- Thiago Arzua
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Yasheng Yan
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Congshan Jiang
- Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Sarah Logan
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
- Department of Physiology, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Reilly L Allison
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Clive Wells
- Department of Microbiology, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Suresh N Kumar
- Department of Pathology, Children's Research Institute Imaging Core, Neuroscience Imaging Facility, Medical College of Wisconsin, Milwaukee, 53226, WI, USA
| | - Richard Schäfer
- Institute for Transfusion Medicine and Immunohaematology, German Red Cross Blood Donor Service Baden-Württemberg-Hessen gGmbH, Goethe University Hospital, 60438, Frankfurt am Main, Germany
| | - Xiaowen Bai
- Department of Cell Biology, Neurobiology & Anatomy, Medical College of Wisconsin, Milwaukee, 53226, WI, USA.
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14
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Horsey EA, Maletta T, Turner H, Cole C, Lehmann H, Fournier NM. Chronic Jet Lag Simulation Decreases Hippocampal Neurogenesis and Enhances Depressive Behaviors and Cognitive Deficits in Adult Male Rats. Front Behav Neurosci 2020; 13:272. [PMID: 31969809 PMCID: PMC6960209 DOI: 10.3389/fnbeh.2019.00272] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 11/29/2019] [Indexed: 11/13/2022] Open
Abstract
There is a long history that protracted periods of circadian disruption, such as through frequent transmeridian travel or rotating shift work, can have a significant impact on brain function and health. In addition, several studies have shown that chronic periods of circadian misalignment can be a significant risk factor for the development of depression and anxiety in some individuals with a history of psychiatric illness. In animal models, circadian disruption can be introduced through either phase advances or delays in the light-dark cycle. However, the impact of chronic phase shifts on affective behavior in rats has not been well-studied. In the present study, male rats were subjected to either weekly 6 h phase advances (e.g., traveling eastbound from New York to Paris) or 6 h phase delays (e.g., traveling westbound from New York to Hawaii) in their light/dark cycle for 8 weeks. The effect of chronic phase shifts was then examined on a range of emotional and cognitive behaviors. We found that rats exposed to frequent phase advances, which mirror conditions of chronic jet lag in humans, exhibited impairments in object recognition memory and showed signature symptoms of depression, including anhedonia, increased anxiety behavior, and higher levels of immobility in the forced swim test. In addition, rats housed on the phase advance schedule also had lower levels of hippocampal neurogenesis and immature neurons showed reduced dendritic complexity compared to controls. These behavioral and neurogenic changes were direction-specific and were not observed after frequent phase delays. Taken together, these findings support the view that circadian disruption through chronic jet lag exposure can suppress hippocampal neurogenesis, which can have a significant impact on memory and mood-related behaviors.
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Affiliation(s)
- Emily A Horsey
- Department of Psychology, Trent University, Peterborough, ON, Canada
| | - Teresa Maletta
- Department of Psychology, Trent University, Peterborough, ON, Canada
| | - Holly Turner
- Department of Psychology, Trent University, Peterborough, ON, Canada
| | - Chantel Cole
- Department of Psychology, Trent University, Peterborough, ON, Canada
| | - Hugo Lehmann
- Department of Psychology, Trent University, Peterborough, ON, Canada
| | - Neil M Fournier
- Department of Psychology, Trent University, Peterborough, ON, Canada
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15
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Qiu X, Ping S, Kyle M, Longo J, Chin L, Zhao LR. S100 Calcium-Binding Protein A9 Knockout Contributes to Neuroprotection and Functional Improvement after Traumatic Brain Injury. J Neurotrauma 2019; 37:950-965. [PMID: 31621496 DOI: 10.1089/neu.2018.6170] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
S100 calcium-binding protein A9 (S100a9), a proinflammatory protein, has been shown to be involved in the development of neuroinflammatory disorders and neurodegenerative diseases. Upregulation of S100a9 in the brain during acute brain injury has been proposed to be associated with acute neuroinflammation. However, it remains unclear whether eliminating S100a9 expression will show beneficial outcomes after traumatic brain injury (TBI). Using S100a9 knockout mice, this study has demonstrated that S100a9 deletion ameliorates post-TBI anxiety, improves TBI-impaired motor and cognitive function, reduces lesion size, prevents perilesional neuron loss and neurodegeneration, diminishes neuroinflammation and TBI-induced neurogenesis, and enhances perilesional expression of neuroplasticity protein. These findings suggest that S100a9 plays a detrimental role in TBI. Genetic deletion of S100a9 enhances neuroprotection and improves functional outcome after TBI. This study sheds light on the pathological involvement of S100a9 in TBI, which would provide a new therapeutic target to minimize TBI-induced brain damage.
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Affiliation(s)
- Xuecheng Qiu
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York
| | - Suning Ping
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York
| | - Michele Kyle
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York
| | - John Longo
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York
| | - Lawrence Chin
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York
| | - Li-Ru Zhao
- Department of Neurosurgery, State University of New York Upstate Medical University, Syracuse, New York.,VA Health Care Upstate New York, Syracuse VA Medical Center, Syracuse, New York
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16
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Gonzalez-Reyes LE, Chiang CC, Zhang M, Johnson J, Arrillaga-Tamez M, Couturier NH, Reddy N, Starikov L, Capadona JR, Kottmann AH, Durand DM. Sonic Hedgehog is expressed by hilar mossy cells and regulates cellular survival and neurogenesis in the adult hippocampus. Sci Rep 2019; 9:17402. [PMID: 31758070 PMCID: PMC6874678 DOI: 10.1038/s41598-019-53192-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/29/2019] [Indexed: 12/12/2022] Open
Abstract
Sonic hedgehog (Shh) is a multifunctional signaling protein governing pattern formation, proliferation and cell survival during embryogenesis. In the adult brain, Shh has neurotrophic function and is implicated in hippocampal neurogenesis but the cellular source of Shh in the hippocampus remains ill defined. Here, we utilize a gene expression tracer allele of Shh (Shh-nlacZ) which allowed the identification of a subpopulation of hilar neurons known as mossy cells (MCs) as a prominent and dynamic source of Shh within the dentate gyrus. AAV-Cre mediated ablation of Shh in the adult dentate gyrus led to a marked degeneration of MCs. Conversely, chemical stimulation of hippocampal neurons using the epileptogenic agent kainic acid (KA) increased the number of Shh+ MCs indicating that the expression of Shh by MCs confers a survival advantage during the response to excitotoxic insults. In addition, ablation of Shh in the adult dentate gyrus led to increased neural precursor cell proliferation and their migration into the subgranular cell layer demonstrating that MCs-generated Shh is a key modulator of hippocampal neurogenesis.
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Affiliation(s)
- Luis E Gonzalez-Reyes
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA.
- Advanced Platform Technology Center, L. Stokes Cleveland VA Medical Center, Rehab. R&D, 10701 East Blvd. Mail Stop 151 AW/APT, Cleveland, OH, 44106, USA.
| | - Chia-Chu Chiang
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Mingming Zhang
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Joshua Johnson
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Manuel Arrillaga-Tamez
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Nicholas H Couturier
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Neha Reddy
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
| | - Lev Starikov
- Department of Molecular, Cellular and Biomedical Sciences, CUNY School of Medicine at City College of New York and Graduate Center, City University of New York, New York, NY, 10031, USA
| | - Jeffrey R Capadona
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
- Advanced Platform Technology Center, L. Stokes Cleveland VA Medical Center, Rehab. R&D, 10701 East Blvd. Mail Stop 151 AW/APT, Cleveland, OH, 44106, USA
| | - Andreas H Kottmann
- Department of Molecular, Cellular and Biomedical Sciences, CUNY School of Medicine at City College of New York and Graduate Center, City University of New York, New York, NY, 10031, USA
| | - Dominique M Durand
- Neural Engineering Center, Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, 44106, USA
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17
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Herold C, Schlömer P, Mafoppa-Fomat I, Mehlhorn J, Amunts K, Axer M. The hippocampus of birds in a view of evolutionary connectomics. Cortex 2019; 118:165-187. [DOI: 10.1016/j.cortex.2018.09.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 09/26/2018] [Accepted: 09/26/2018] [Indexed: 12/12/2022]
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18
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Eyre MD, Bartos M. Somatostatin-Expressing Interneurons Form Axonal Projections to the Contralateral Hippocampus. Front Neural Circuits 2019; 13:56. [PMID: 31507383 PMCID: PMC6716454 DOI: 10.3389/fncir.2019.00056] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 08/08/2019] [Indexed: 12/31/2022] Open
Abstract
Conscious memories are critically dependent upon bilateral hippocampal formation, and interhemispheric commissural projections made by mossy cells and CA3 pyramidal cells. GABAergic interneurons also make long-range axonal projections, but little is known regarding their commissural, inter-hippocampal connections. We used retrograde and adeno-associated viral tracing, immunofluorescence and electron microscopy, and in vitro optogenetics to assess contralateral projections of neurochemically defined interneuron classes. We found that contralateral-projecting interneurons were 24-fold less common compared to hilar mossy cells, and mostly consisted of somatostatin- and parvalbumin-expressing types. Somatostatin-expressing cells made denser contralateral axonal projections than parvalbumin-expressing cells, although this was typically 10-fold less than the ipsilateral projection density. Somatostatin-expressing cells displayed a topographic-like innervation according to the location of their somata, whereas parvalbumin-expressing cells mostly innervated CA1. In the dentate gyrus molecular layer, commissural interneuron post-synaptic targets were predominantly putative granule cell apical dendrites. In the hilus, varicosities in close vicinity to various interneuron subtypes, as well as mossy cells, were observed, but most contralateral axon varicosities had no adjacent immunolabeled structure. Due to the relative sparsity of the connection and the likely distal dendritic location of their synapses, commissural projections made by interneurons were found to be weak. We postulate that these projections may become functionally active upon intense network activity during tasks requiring increased memory processing.
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Affiliation(s)
- Mark D Eyre
- Medical Faculty, Institute for Physiology I, Systemic and Cellular Neurophysiology, University of Freiburg, Freiburg, Germany
| | - Marlene Bartos
- Medical Faculty, Institute for Physiology I, Systemic and Cellular Neurophysiology, University of Freiburg, Freiburg, Germany
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19
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An Autaptic Culture System for Standardized Analyses of iPSC-Derived Human Neurons. Cell Rep 2019; 27:2212-2228.e7. [DOI: 10.1016/j.celrep.2019.04.059] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 02/05/2019] [Accepted: 04/10/2019] [Indexed: 11/17/2022] Open
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20
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Rodríguez-Iglesias N, Sierra A, Valero J. Rewiring of Memory Circuits: Connecting Adult Newborn Neurons With the Help of Microglia. Front Cell Dev Biol 2019; 7:24. [PMID: 30891446 PMCID: PMC6411767 DOI: 10.3389/fcell.2019.00024] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/08/2019] [Indexed: 12/16/2022] Open
Abstract
New neurons are continuously generated from stem cells and integrated into the adult hippocampal circuitry, contributing to memory function. Several environmental, cellular, and molecular factors regulate the formation of new neurons, but the mechanisms that govern their incorporation into memory circuits are less explored. Herein we will focus on microglia, the resident immune cells of the CNS, which modulate the production of new neurons in the adult hippocampus and are also well suited to participate in their circuit integration. Microglia may contribute to the refinement of brain circuits during development and exert a role in physiological and pathological conditions by regulating axonal and dendritic growth; promoting the formation, elimination, and relocation of synapses; modulating excitatory synaptic maturation; and participating in functional synaptic plasticity. Importantly, microglia are able to sense subtle changes in their environment and may use this information to differently modulate hippocampal wiring, ultimately impacting on memory function. Deciphering the role of microglia in hippocampal circuitry constant rewiring will help to better understand the influence of microglia on memory function.
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Affiliation(s)
- Noelia Rodríguez-Iglesias
- Laboratory of Glial Cell Biology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Department of Neuroscience, University of the Basque Country UPV/EHU, Leioa, Spain
| | - Amanda Sierra
- Laboratory of Glial Cell Biology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Department of Neuroscience, University of the Basque Country UPV/EHU, Leioa, Spain.,Ikerbasque Foundation, Bilbao, Spain
| | - Jorge Valero
- Laboratory of Glial Cell Biology, Achucarro Basque Center for Neuroscience, Leioa, Spain.,Department of Neuroscience, University of the Basque Country UPV/EHU, Leioa, Spain.,Ikerbasque Foundation, Bilbao, Spain
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21
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Yau SY, Bettio L, Chiu J, Chiu C, Christie BR. Fragile-X Syndrome Is Associated With NMDA Receptor Hypofunction and Reduced Dendritic Complexity in Mature Dentate Granule Cells. Front Mol Neurosci 2019; 11:495. [PMID: 30705620 PMCID: PMC6344420 DOI: 10.3389/fnmol.2018.00495] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 12/27/2018] [Indexed: 12/11/2022] Open
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability. It is caused by the overexpansion of cytosine-guanine-guanine (CGG) trinucleotide in Fmr1 gene, resulting in complete loss of the fragile X mental retardation protein (FMRP). Previous studies using Fmr1 knockout (Fmr1 KO) mice have suggested that a N-methyl-D-aspartate receptors (NMDAR) hypofunction in the hippocampal dentate gyrus may partly contribute to cognitive impairments in FXS. Since activation of NMDAR plays an important role in dendritic arborization during neuronal development, we examined whether deficits in NMDAR function are associated with alterations in dendritic complexity in the hippocampal dentate region. The dentate granule cell layer (GCL) presents active postnatal neurogenesis, and consists of a heterogenous neuronal population with gradient ages from the superficial to its deep layer. Here, we show that neurons with multiple primary dendrites that reside in the outer GCL of Fmr1 KO mice display significantly smaller NMDAR excitatory post-synaptic currents (EPSCs) and a higher α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) to NMDA ratio in comparison to their wild-type counterparts. These deficits were associated with a significant decrease in dendritic complexity, with both dendritic length and number of intersections being significantly reduced. In contrast, although neurons with a single primary dendrite resided in the inner GCL of Fmr1 KO mice had a trend toward a reduction in NMDAR EPSCs and a higher AMPA/NMDA ratio, no alterations were found in dendritic complexity at this developmental stage. Our data indicate that the loss of FMRP causes NMDAR deficits and reduced dendritic complexity in granule neurons with multiple primary dendrites which are thought to be more mature in the GCL.
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Affiliation(s)
- Suk-Yu Yau
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, BC, Canada
| | - Luis Bettio
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, BC, Canada
| | - Jason Chiu
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, BC, Canada
| | - Christine Chiu
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, BC, Canada
| | - Brian R Christie
- Division of Medical Sciences, Island Medical Program, University of Victoria, Victoria, BC, Canada
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Stroke Accelerates and Uncouples Intrinsic and Synaptic Excitability Maturation of Mouse Hippocampal DCX + Adult-Born Granule Cells. J Neurosci 2019; 39:1755-1766. [PMID: 30617211 DOI: 10.1523/jneurosci.3303-17.2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 11/05/2018] [Accepted: 11/08/2018] [Indexed: 11/21/2022] Open
Abstract
Stroke robustly stimulates adult neurogenesis in the hippocampal dentate gyrus. It is currently unknown whether this process induces beneficial or maladaptive effects, but morphological and behavioral studies have reported aberrant neurogenesis and impaired hippocampal-dependent memory following stroke. However, the intrinsic function and network incorporation of adult-born granule cells (ABGCs) after ischemia is unclear. Using patch-clamp electrophysiology, we evaluated doublecortin-positive (DCX+) ABGCs as well as DCX- dentate gyrus granule cells 2 weeks after a stroke or sham operation in DCX/DsRed transgenic mice of either sex. The developmental status, intrinsic excitability, and synaptic excitability of ABGCs were accelerated following stroke, while dendritic morphology was not aberrant. Regression analysis revealed uncoupled development of intrinsic and network excitability, resulting in young, intrinsically hyperexcitable ABGCs receiving disproportionately large glutamatergic inputs. This aberrant functional maturation in the subgroup of ABGCs in the hippocampus may contribute to defective hippocampal function and increased seizure susceptibility following stroke.SIGNIFICANCE STATEMENT Stroke increases hippocampal neurogenesis but the functional consequences of the postlesional response is mostly unclear. Our findings provide novel evidence of aberrant functional maturation of newly generated neurons following stroke. We demonstrate that stroke not only causes an accelerated maturation of the intrinsic and synaptic parameters of doublecortin-positive, new granule cells in the hippocampus, but that this accelerated development does not follow physiological dynamics due to uncoupled intrinsic and synaptic maturation. Hyperexcitable immature neurons may contribute to disrupted network integration following stroke.
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23
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O'Neill N, McLaughlin C, Komiyama N, Sylantyev S. Biphasic Modulation of NMDA Receptor Function by Metabotropic Glutamate Receptors. J Neurosci 2018; 38:9840-9855. [PMID: 30282730 PMCID: PMC6234301 DOI: 10.1523/jneurosci.1000-18.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 09/02/2018] [Accepted: 09/09/2018] [Indexed: 01/14/2023] Open
Abstract
A recently reported rapid potentiation of NMDA receptors by Group I metabotropic glutamate receptors (mGluRIs) via a Homer protein link is distinct from the classical, relatively slow inhibitory G-protein-associated signaling triggered by mGluRI activation. The relationship between these two mechanisms remains unknown. Here, we focused on the mGluRI-dependent modulation of NMDAR response in hippocampal dentate gyrus granule cells and cerebellar granule cells of C57BL6-J mice and found that these two contrasting mechanisms overlap competitively on the time scale from hundreds of milliseconds to seconds, with the net effect depending on the cell type. At a shorter time interval (units of millisecond), the Homer-mediated signal from mGluRIs prevails, causing upregulation of NMDAR function, in both dentate gyrus granule cells and cerebellar granule cells. Our results shed light on the possible mechanisms of anti-schizophrenia drugs that disrupt Homer-containing protein link.SIGNIFICANCE STATEMENT Here we study modulation of NMDA receptors triggered by activation of metabotropic glutamate receptors Group I via two distinct pathways: classical G-protein signaling system and newly discovered high-speed modulatory mechanism associated with Homer-protein-containing direct molecular link. We found that these two contrasting mechanisms overlap competitively on the time scale from hundreds of milliseconds to seconds, with the net effect depending on the cell type. We have also found that both crosstalk mechanisms cause significant changes in synaptic strength and plasticity. Our results resolve an apparent discrepancy between earlier studies that demonstrated contradictive effects of Homer-containing protein link disruption on NMDA receptor signaling. On top of that, our data provide a plausible explanation for unclear action mechanisms of anti-schizophrenia drugs.
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Affiliation(s)
- Nathanael O'Neill
- Centre for Clinical Brain Sciences, University of Edinburgh, EH16 4SB, Edinburgh, United Kingdom
| | - Catherine McLaughlin
- Centre for Clinical Brain Sciences, University of Edinburgh, EH16 4SB, Edinburgh, United Kingdom
| | - Noboru Komiyama
- Centre for Clinical Brain Sciences, University of Edinburgh, EH16 4SB, Edinburgh, United Kingdom
- Centre for Neuroregeneration, University of Edinburgh, EH16 4SB, Edinburgh, United Kingdom, and
| | - Sergiy Sylantyev
- Centre for Clinical Brain Sciences, University of Edinburgh, EH16 4SB, Edinburgh, United Kingdom,
- Department for Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
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24
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Benito N, Gaborieau E, Sanz Diez A, Kosar S, Foucault L, Raineteau O, De Saint Jan D. A Pool of Postnatally Generated Interneurons Persists in an Immature Stage in the Olfactory Bulb. J Neurosci 2018; 38:9870-9882. [PMID: 30282727 PMCID: PMC6596244 DOI: 10.1523/jneurosci.1216-18.2018] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 07/31/2018] [Accepted: 08/09/2018] [Indexed: 02/01/2023] Open
Abstract
Calretinin (CR)-expressing periglomerular (PG) cells are the most abundant interneurons in the glomerular layer of the olfactory bulb. They are predominately generated postnatally from the septal and dorsal subventricular zones that continue producing them well into adulthood. Yet, little is known about their properties and functions. Using transgenic approaches and patch-clamp recording in mice of both sexes we show that CR(+) PG cells of both septal and dorsal origin have homogeneous morphological and electrophysiological properties. However, unlike other PG cells, these axonless neurons express a surprisingly small repertoire of voltage-activated channels and do not fire or fire at most a single and often small action potential. Moreover, they are not innervated by olfactory sensory neurons and receive little synaptic inputs from mitral or tufted cells at excitatory synapses where NMDA receptors predominate. These membrane and synaptic properties, that resemble those of newborn immature neurons not yet integrated in the network, persist over time and limit the recruitment of CR(+) PG cells by afferent inputs that strongly drive local network activity. Together, our results show that postnatally generated CR(+) PG cells continuously supply a large pool of neurons with unconventional properties. These data also question the contribution of CR(+) PG cells in olfactory bulb computation.SIGNIFICANCE STATEMENT Calretinin-expressing PG cells are by far the most abundant interneurons in the glomerular layer of the olfactory bulb. They are continuously produced during postnatal life, including adulthood, from neural stem cells located in the subventricular zones. Surprisingly, unlike other postnatally generated newborn neurons that quickly integrate into preexisting olfactory bulb networks, calretinin-expressing PG cells retain immature properties that limit their recruitment in local network activity for weeks, if not months, as if they would never fully mature. The function of this so far unsuspected pool of latent neurons is still unknown.
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Affiliation(s)
- Nuria Benito
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67084 Strasbourg, France, and
| | - Elodie Gaborieau
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Alvaro Sanz Diez
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67084 Strasbourg, France, and
| | - Seher Kosar
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67084 Strasbourg, France, and
| | - Louis Foucault
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Olivier Raineteau
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500 Bron, France
| | - Didier De Saint Jan
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Université de Strasbourg, 67084 Strasbourg, France, and
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25
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Zuo Y, Wang J, Liao F, Yan X, Li J, Huang L, Liu F. Inhibition of Heat Shock Protein 90 by 17-AAG Reduces Inflammation via P2X7 Receptor/NLRP3 Inflammasome Pathway and Increases Neurogenesis After Subarachnoid Hemorrhage in Mice. Front Mol Neurosci 2018; 11:401. [PMID: 30459553 PMCID: PMC6232389 DOI: 10.3389/fnmol.2018.00401] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/12/2018] [Indexed: 12/23/2022] Open
Abstract
Subarachnoid hemorrhage (SAH) is a life-threatening cerebrovascular disease that usually has a poor prognosis. Heat shock proteins (HSPs) have been implicated in the mechanisms of SAH-associated damage, including increased inflammation and reduced neurogenesis. The aim of this study was to investigate the effects of HSP90 inhibition on inflammation and neurogenesis in a mouse model of experimental SAH induced by endovascular surgery. Western blotting showed HSP90 levels to be decreased, while neurogenesis, evaluated by 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry, was decreased in the hippocampuses of SAH mice. SAH also induced pro-inflammatory factors such as interleukin-1β (IL-1β), capase-1 and the NLRP3 inflammasome. However, intraperitoneal administration of the specific HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG) reduced the levels of HSP90, NLRP3, ASC, caspase-1 and IL-1β, while increasing the levels of brain-derived neurotrophic factor and doublecortin (DCX), as well as the number of BrdU-positive cells in SAH mice. In addition, 17-AGG improved short- and long-term neurobehavioral outcomes. The neuroprotective and anti-inflammatory effects of 17-AGG were reversed by recombinant HSP90 (rHSP90); this detrimental effect of HSP90 was inhibited by the specific P2X7 receptor (P2X7R) inhibitor A438079, indicating that SAH-induced inflammation and inhibition of neurogenesis were likely mediated by HSP90 and the P2X7R/NLRP3 inflammasome pathway. HSP90 inhibition by 17-AAG may be a promising therapeutic strategy for the treatment of SAH.
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Affiliation(s)
- Yuchun Zuo
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Jikai Wang
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Fan Liao
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
| | - Xiaoxin Yan
- Department of Anatomy, XiangYa Medical School, Central South University, Changsha, China
| | - Jianming Li
- Neuroscience Research Center, Changsha Medical University, Changsha, China
| | - Lei Huang
- Department of Physiology and Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA, United States.,Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Fei Liu
- Department of Neurosurgery, Third XiangYa Hospital, Central South University, Changsha, China
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26
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Annamneedi A, Caliskan G, Müller S, Montag D, Budinger E, Angenstein F, Fejtova A, Tischmeyer W, Gundelfinger ED, Stork O. Ablation of the presynaptic organizer Bassoon in excitatory neurons retards dentate gyrus maturation and enhances learning performance. Brain Struct Funct 2018; 223:3423-3445. [PMID: 29915867 PMCID: PMC6132633 DOI: 10.1007/s00429-018-1692-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 05/30/2018] [Indexed: 01/05/2023]
Abstract
Bassoon is a large scaffolding protein of the presynaptic active zone involved in the development of presynaptic terminals and in the regulation of neurotransmitter release at both excitatory and inhibitory brain synapses. Mice with constitutive ablation of the Bassoon (Bsn) gene display impaired presynaptic function, show sensory deficits and develop severe seizures. To specifically study the role of Bassoon at excitatory forebrain synapses and its relevance for control of behavior, we generated conditional knockout (Bsn cKO) mice by gene ablation through an Emx1 promoter-driven Cre recombinase. In these animals, we confirm selective loss of Bassoon from glutamatergic neurons of the forebrain. Behavioral assessment revealed that, in comparison to wild-type littermates, Bsn cKO mice display selectively enhanced contextual fear memory and increased novelty preference in a spatial discrimination/pattern separation task. These changes are accompanied by an augmentation of baseline synaptic transmission at medial perforant path to dentate gyrus (DG) synapses, as indicated by increased ratios of field excitatory postsynaptic potential slope to fiber volley amplitude. At the structural level, an increased complexity of apical dendrites of DG granule cells can be detected in Bsn cKO mice. In addition, alterations in the expression of cellular maturation markers and a lack of age-dependent decrease in excitability between juvenile and adult Bsn cKO mice are observed. Our data suggest that expression of Bassoon in excitatory forebrain neurons is required for the normal maturation of the DG and important for spatial and contextual memory.
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Affiliation(s)
- Anil Annamneedi
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Gürsel Caliskan
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Sabrina Müller
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Dirk Montag
- Neurogenetics Laboratory, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Eike Budinger
- Department of Systems Physiology of Learning, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Frank Angenstein
- Special Laboratory Noninvasive Brain Imaging, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Functional Neuroimaging Group, German Center for Neurodegenerative Diseases, Magdeburg, Germany
| | - Anna Fejtova
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- RG Presynaptic Plasticity, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Department of Psychiatry and Psychotherapy, University Hospital, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
| | - Wolfgang Tischmeyer
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Special Laboratory Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Eckart D. Gundelfinger
- Department of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
- Molecular Neuroscience, Medical School, Otto von Guericke University, Magdeburg, Germany
| | - Oliver Stork
- Department of Genetics and Molecular Neurobiology, Institute of Biology, Otto-von-Guericke-University, Magdeburg, Germany
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
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27
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Strehl A, Galanis C, Radic T, Schwarzacher SW, Deller T, Vlachos A. Dopamine Modulates Homeostatic Excitatory Synaptic Plasticity of Immature Dentate Granule Cells in Entorhino-Hippocampal Slice Cultures. Front Mol Neurosci 2018; 11:303. [PMID: 30214394 PMCID: PMC6125303 DOI: 10.3389/fnmol.2018.00303] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 08/09/2018] [Indexed: 01/27/2023] Open
Abstract
Homeostatic plasticity mechanisms maintain neurons in a stable state. To what extent these mechanisms are relevant during the structural and functional maturation of neural tissue is poorly understood. To reveal developmental changes of a major homeostatic plasticity mechanism, i.e., homeostatic excitatory synaptic plasticity, we analyzed 1-week- and 4-week-old entorhino-hippocampal slice cultures and investigated the ability of immature and mature dentate granule cells (GCs) to express this form of plasticity. Our experiments demonstrate that immature GCs are capable of adjusting their excitatory synaptic strength in a compensatory manner at early postnatal stages, i.e., in 1-week-old preparations, as is the case for mature GCs. This ability of immature dentate GCs is absent in 4-week-old slice cultures. Further investigations into the signaling pathways reveal an important role of dopamine (DA), which prevents homeostatic synaptic up-scaling of immature GCs in young cultures, whereas it does not affect immature and mature GCs in 4-week-old preparations. Together, these results disclose the ability of immature GCs to express homeostatic synaptic plasticity during early postnatal development. They hint toward a novel role of dopaminergic signaling, which may gate activity-dependent changes of newly born neurons by blocking homeostasis.
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Affiliation(s)
- Andreas Strehl
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tijana Radic
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | | | - Thomas Deller
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany
| | - Andreas Vlachos
- Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe-University Frankfurt, Frankfurt, Germany.,Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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28
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Abstract
The brain is a dynamic organ of the biological renaissance due to the existence of neuroplasticity. Adult neurogenesis abides by every aspect of neuroplasticity in the intact brain and contributes to neural regeneration in response to brain diseases and injury. The occurrence of adult neurogenesis has unequivocally been witnessed in human subjects, experimental and wildlife research including rodents, bats and cetaceans. Adult neurogenesis is a complex cellular process, in which generation of neuroblasts namely, neuroblastosis appears to be an integral process that occur in the limbic system and basal ganglia in addition to the canonical neurogenic niches. Neuroblastosis can be regulated by various factors and contributes to different functions of the brain. The characteristics and fate of neuroblasts have been found to be different among mammals regardless of their cognitive functions. Recently, regulation of neuroblastosis has been proposed for the sensorimotor interface and regenerative neuroplasticity of the adult brain. Hence, the understanding of adult neurogenesis at the functional level of neuroblasts requires a great scientific attention. Therefore, this mini-review provides a glimpse into the conceptual development of neuroplasticity, discusses the possible role of different types of neuroblasts and signifies neuroregenerative failure as a potential cause of dementia.
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Affiliation(s)
- Mahesh Kandasamy
- Laboratory of Stem Cells and Neuroregeneration, Department of Animal Science, School of Life Sciences, Bharathidasan University, Tiruchirappalli, Tamil Nadu; Faculty Recharge Programme, University Grants Commission (UGC-FRP), New Delhi, India
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Salzburg, Paracelsus Medical University; Spinal Cord Injury and Tissue Regeneration Center, Salzburg, Paracelsus Medical University, Salzburg, Austria
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29
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Jhaveri DJ, Tedoldi A, Hunt S, Sullivan R, Watts NR, Power JM, Bartlett PF, Sah P. Evidence for newly generated interneurons in the basolateral amygdala of adult mice. Mol Psychiatry 2018; 23:521-532. [PMID: 28809399 PMCID: PMC5822453 DOI: 10.1038/mp.2017.134] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 11/27/2022]
Abstract
New neurons are continually generated from the resident populations of precursor cells in selective niches of the adult mammalian brain such as the hippocampal dentate gyrus and the olfactory bulb. However, whether such cells are present in the adult amygdala, and their neurogenic capacity, is not known. Using the neurosphere assay, we demonstrate that a small number of precursor cells, the majority of which express Achaete-scute complex homolog 1 (Ascl1), are present in the basolateral amygdala (BLA) of the adult mouse. Using neuron-specific Thy1-YFP transgenic mice, we show that YFP+ cells in BLA-derived neurospheres have a neuronal morphology, co-express the neuronal marker βIII-tubulin, and generate action potentials, confirming their neuronal phenotype. In vivo, we demonstrate the presence of newly generated BrdU-labeled cells in the adult BLA, and show that a proportion of these cells co-express the immature neuronal marker doublecortin (DCX). Furthermore, we reveal that a significant proportion of GFP+ neurons (~23%) in the BLA are newly generated (BrdU+) in DCX-GFP mice, and using whole-cell recordings in acute slices we demonstrate that the GFP+ cells display electrophysiological properties that are characteristic of interneurons. Using retrovirus-GFP labeling as well as the Ascl1CreERT2 mouse line, we further confirm that the precursor cells within the BLA give rise to mature and functional interneurons that persist in the BLA for at least 8 weeks after their birth. Contextual fear conditioning has no effect on the number of neurospheres or BrdU-labeled cells in the BLA, but produces an increase in hippocampal cell proliferation. These results demonstrate that neurogenic precursor cells are present in the adult BLA, and generate functional interneurons, but also show that their activity is not regulated by an amygdala-dependent learning paradigm.
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Affiliation(s)
- D J Jhaveri
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
| | - A Tedoldi
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - S Hunt
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - R Sullivan
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - N R Watts
- Critical Care and Trauma Division, The George Institute for Global Health, Sydney, NSW, Australia
| | - J M Power
- School of Medical Science, University of New South Wales, Sydney, NSW, Australia
| | - P F Bartlett
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
| | - P Sah
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
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30
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Seth B, Yadav A, Agarwal S, Tiwari SK, Chaturvedi RK. Inhibition of the transforming growth factor-β/SMAD cascade mitigates the anti-neurogenic effects of the carbamate pesticide carbofuran. J Biol Chem 2017; 292:19423-19440. [PMID: 28982980 DOI: 10.1074/jbc.m117.798074] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 09/29/2017] [Indexed: 12/22/2022] Open
Abstract
The widely used carbamate pesticide carbofuran causes neurophysiological and neurobehavioral deficits in rodents and humans and therefore poses serious health hazards around the world. Previously, we reported that gestational carbofuran exposure has detrimental effects on hippocampal neurogenesis, the generation of new neurons from neural stem cells (NSC), in offspring. However, the underlying cellular and molecular mechanisms for carbofuran-impaired neurogenesis remain unknown. Herein, we observed that chronic carbofuran exposure from gestational day 7 to postnatal day 21 altered expression of genes and transcription factors and levels of proteins involved in neurogenesis and the TGF-β pathway (i.e. TGF-β; SMAD-2, -3, and -7; and SMURF-2) in the rat hippocampus. We found that carbofuran increases TGF-β signaling (i.e. increased phosphorylated SMAD-2/3 and reduced SMAD-7 expression) in the hippocampus, which reduced NSC proliferation because of increased p21 levels and reduced cyclin D1 levels. Moreover, the carbofuran-altered TGF-β signaling impaired neuronal differentiation (BrdU/DCX+ and BrdU/NeuN+ cells) and increased apoptosis and neurodegeneration in the hippocampus. Blockade of the TGF-β pathway with the specific inhibitor SB431542 and via SMAD-3 siRNA prevented carbofuran-mediated inhibition of neurogenesis in both hippocampal NSC cultures and the hippocampus, suggesting the specific involvement of this pathway. Of note, both in vitro and in vivo studies indicated that TGF-β pathway attenuation reverses carbofuran's inhibitory effects on neurogenesis and associated learning and memory deficits. These results suggest that carbofuran inhibits NSC proliferation and neuronal differentiation by altering TGF-β signaling. Therefore, we conclude that TGF-β may represent a potential therapeutic target against carbofuran-mediated neurotoxicity and neurogenesis disruption.
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Affiliation(s)
- Brashket Seth
- From the Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India.,the Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Lucknow Campus, Lucknow 226001, Uttar Pradesh, India
| | - Anuradha Yadav
- From the Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India.,the Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Lucknow Campus, Lucknow 226001, Uttar Pradesh, India
| | - Swati Agarwal
- From the Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India.,the Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, and
| | - Shashi Kant Tiwari
- From the Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India.,the Department of Pediatrics, University of California San Diego, La Jolla, California 92093
| | - Rajnish Kumar Chaturvedi
- From the Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhavan, 31, Mahatma Gandhi Marg, Lucknow 226001, Uttar Pradesh, India, .,the Academy of Scientific and Innovative Research (AcSIR), CSIR-IITR Lucknow Campus, Lucknow 226001, Uttar Pradesh, India
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31
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Sah N, Peterson BD, Lubejko ST, Vivar C, van Praag H. Running reorganizes the circuitry of one-week-old adult-born hippocampal neurons. Sci Rep 2017; 7:10903. [PMID: 28883658 PMCID: PMC5589841 DOI: 10.1038/s41598-017-11268-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 07/05/2017] [Indexed: 12/23/2022] Open
Abstract
Adult hippocampal neurogenesis is an important form of structural and functional plasticity in the mature mammalian brain. The existing consensus is that GABA regulates the initial integration of adult-born neurons, similar to neuronal development during embryogenesis. Surprisingly, virus-based anatomical tracing revealed that very young, one-week-old, new granule cells in male C57Bl/6 mice receive input not only from GABAergic interneurons, but also from multiple glutamatergic cell types, including mature dentate granule cells, area CA1-3 pyramidal cells and mossy cells. Consistently, patch-clamp recordings from retrovirally labeled new granule cells at 7-8 days post retroviral injection (dpi) show that these cells respond to NMDA application with tonic currents, and that both electrical and optogenetic stimulation can evoke NMDA-mediated synaptic responses. Furthermore, new dentate granule cell number, morphology and excitatory synaptic inputs at 7 dpi are modified by voluntary wheel running. Overall, glutamatergic and GABAergic innervation of newly born neurons in the adult hippocampus develops concurrently, and excitatory input is reorganized by exercise.
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Affiliation(s)
- Nirnath Sah
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Benjamin D Peterson
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Susan T Lubejko
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA
| | - Carmen Vivar
- Laboratory of Neurogenesis and Neuroplasticity, Department of Physiology, Biophysics, and Neuroscience, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, 07360, Mexico.
| | - Henriette van Praag
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, MD, 21224, USA.
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32
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Dey A, Farzanehfar P, Gazina EV, Aumann TD. Electrophysiological and gene expression characterization of the ontogeny of nestin-expressing cells in the adult mouse midbrain. Stem Cell Res 2017; 23:143-153. [PMID: 28743044 DOI: 10.1016/j.scr.2017.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 05/19/2017] [Accepted: 07/01/2017] [Indexed: 10/19/2022] Open
Abstract
The birth of new neurons, or neurogenesis, in the adult midbrain is important for progressing dopamine cell-replacement therapies for Parkinson's disease. Most studies suggest newborn cells remain undifferentiated or differentiate into glia within the adult midbrain. However, some studies suggest nestin+neural precursor cells (NPCs) have a propensity to generate new neurons here. We sought to confirm this by administering tamoxifen to adult NesCreERT2/R26eYFP transgenic mice, which permanently labelled adult nestin-expressing cells and their progeny with enhanced yellow fluorescent protein (eYFP). eYFP+ midbrain cells were then characterized 1-32weeks later in acutely prepared brain slices using whole-cell patch clamp electrophysiology combined with single-cell RT-qPCR. Most eYFP+ cells exhibited a mature neuronal phenotype with large amplitude fast action potentials (APs), spontaneous post-synaptic currents (sPSCs), and expression of 'mature' neuronal genes (NeuN, Gad1, Gad2 and/or VGLUT2). This was the case even at the earliest time-point following tamoxifen (i.e. 1week). In comparison to neighboring eYFP- (control) cells, eYFP+ cells discharged more APs per unit current injection, and had faster AP time-to-peak, hyperpolarized resting membrane potential, smaller membrane capacitance and shorter duration sPSCs. eYFP+ cells were also differentiated from eYFP- cells by increased expression of 'immature' pro-neuronal genes (Pax6, Ngn2 and/or Msx1). However, further analyses failed to reveal evidence of a place of birth, neuronal differentiation, maturation and integration indicative of classical neurogenesis. Thus our findings do not support the notion that nestin+NPCs in the adult SNc and midbrain generate new neurons via classical neurogenesis. Rather, they raise the possibility that mature neurons express nestin under unknown circumstances, and that this is associated with altered physiology and gene expression.
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Affiliation(s)
- Anupama Dey
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Parisa Farzanehfar
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Elena V Gazina
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
| | - Tim D Aumann
- Florey Institute of Neuroscience & Mental Health, The University of Melbourne, Parkville, Victoria 3010, Australia.
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33
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Feng S, Shi T, Qiu J, Yang H, Wu Y, Zhou W, Wang W, Wu H. Notch1 deficiency in postnatal neural progenitor cells in the dentate gyrus leads to emotional and cognitive impairment. FASEB J 2017; 31:4347-4358. [PMID: 28611114 DOI: 10.1096/fj.201700216rr] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/30/2017] [Indexed: 01/19/2023]
Abstract
It is well known that Notch1 signaling plays a crucial role in embryonic neural development and adult neurogenesis. The latest evidence shows that Notch1 also plays a critical role in synaptic plasticity in mature hippocampal neurons. So far, deeper insights into the function of Notch1 signaling during the different steps of adult neurogenesis are still lacking, and the mechanisms by which Notch1 dysfunction is associated with brain disorders are also poorly understood. In the current study, we found that Notch1 was highly expressed in the adult-born immature neurons in the hippocampal dentate gyrus. Using a genetic approach to selectively ablate Notch1 signaling in late immature precursors in the postnatal hippocampus by cross-breeding doublecortin (DCX)+ neuron-specific proopiomelanocortin (POMC)-α Cre mice with floxed Notch1 mice, we demonstrated a previously unreported pivotal role of Notch1 signaling in survival and function of adult newborn neurons in the dentate gyrus. Moreover, behavioral and functional studies demonstrated that POMC-Notch1-/- mutant mice showed anxiety and depressive-like behavior with impaired synaptic transmission properties in the dentate gyrus. Finally, our mechanistic study showed significantly compromised phosphorylation of cAMP response element-binding protein (CREB) in Notch1 mutants, suggesting that the dysfunction of Notch1 mutants is associated with the disrupted pCREB signaling in postnatally generated immature neurons in the dentate gyrus.-Feng, S., Shi, T., Qiu, J., Yang, H., Wu, Y., Zhou, W., Wang, W., Wu, H. Notch1 deficiency in postnatal neural progenitor cells in the dentate gyrus leads to emotional and cognitive impairment.
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Affiliation(s)
- Shufang Feng
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Tianyao Shi
- Department of Traditional Chinese Medicine (TCM) and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Jiangxia Qiu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Haihong Yang
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yan Wu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Wenxia Zhou
- Department of Traditional Chinese Medicine (TCM) and Neuroimmunopharmacology, Beijing Institute of Pharmacology and Toxicology, Beijing, China
| | - Wei Wang
- Department of Orthopedics Research Institute, First Affiliated Hospital of Jinzhou Medical University, Jinzhou, China
| | - Haitao Wu
- Department of Neurobiology, Beijing Institute of Basic Medical Sciences, Beijing, China; .,Key Laboratory of Neuroregeneration, Coinnovation Center of Neuroregeneration, Nantong University, Nantong, China
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Spampanato J, Sullivan RKP, Perumal MB, Sah P. Development and physiology of GABAergic feedback excitation in parvalbumin expressing interneurons of the mouse basolateral amygdala. Physiol Rep 2016; 4:4/1/e12664. [PMID: 26733246 PMCID: PMC4760394 DOI: 10.14814/phy2.12664] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
We have previously shown that in the basolateral amygdala (BLA), action potentials in one type of parvalbumin (PV)-expressing GABAergic interneuron can evoke a disynaptic feedback excitatory postsynaptic potential (fbEPSP) onto the same presynaptic interneuron. Here, using whole-cell recordings from PV-expressing interneurons in acute brain slices we expand on this finding to show that this response is first detectable at 2-week postnatal, and is most prevalent in animals beyond 3 weeks of age (>P21). This circuit has a very high fidelity, and single action potential evoked fbEPSPs display few failures. Reconstruction of filled neurons, and electron microscopy show that interneurons that receive feedback excitation make symmetrical synapses on both the axon initial segments (AIS), as well as the soma and proximal dendrites of local pyramidal neurons, suggesting fbEPSP interneurons are morphologically distinct from the highly specialized chandelier neurons that selectively target the axon initial segment of pyramidal neurons. Single PV interneurons could trigger very large (~ 1 nA) feedback excitatory postsynaptic currents (fbEPSCs) suggesting that these neurons are heavily reciprocally connected to local glutamatergic principal cells. We conclude that in the BLA, a subpopulation of PV interneurons forms a distinct neural circuit in which a single action potential can recruit multiple pyramidal neurons to discharge near simultaneously and feed back onto the presynaptic interneuron.
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Affiliation(s)
- Jay Spampanato
- The Queensland Brain Institute, The University of Queensland, St. Lucia, Australia
| | - Robert K P Sullivan
- The Queensland Brain Institute, The University of Queensland, St. Lucia, Australia
| | | | - Pankaj Sah
- The Queensland Brain Institute, The University of Queensland, St. Lucia, Australia
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35
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Bidirectional GABAergic control of action potential firing in newborn hippocampal granule cells. Nat Neurosci 2016; 19:263-70. [PMID: 26752162 DOI: 10.1038/nn.4218] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/01/2015] [Indexed: 01/11/2023]
Abstract
Newly generated young neurons in the adult hippocampus receive GABAergic synaptic inputs, which are crucial for activity-dependent survival and functional maturation between 1-3 weeks after mitosis. We found synaptically driven action potential (AP) firing in these newborn young cells in adult mice. Although glutamatergic synaptic inputs remained subthreshold, activation of GABAergic synaptic inputs depolarized young neurons and reliably evoked APs. Furthermore, pairing of subthreshold excitatory postsynaptic potentials or somatic current injection with brief bursts of GABAergic inputs revealed efficient GABAergic excitation at conductances of ∼ 1.5 nS, corresponding to the activity of only three or four interneurons. Stronger GABAergic inputs (>4 nS) effectively blocked AP firing via shunting inhibition, which might be important to dynamically control spiking output in both directions. Taken together, GABAergic interneurons differentially recruit newborn young granule cells by supporting either AP generation or shunting inhibition dependent on hippocampal network activity.
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Brisch R, Bielau H, Saniotis A, Wolf R, Bogerts B, Krell D, Steiner J, Braun K, Krzyżanowska M, Krzyżanowski M, Jankowski Z, Kaliszan M, Bernstein HG, Gos T. Calretinin and parvalbumin in schizophrenia and affective disorders: a mini-review, a perspective on the evolutionary role of calretinin in schizophrenia, and a preliminary post-mortem study of calretinin in the septal nuclei. Front Cell Neurosci 2015; 9:393. [PMID: 26578879 PMCID: PMC4624860 DOI: 10.3389/fncel.2015.00393] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 09/22/2015] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE The septal nuclei are important limbic regions that are involved in emotional behavior and connect to various brain regions such as the habenular complex. Both the septal nuclei and the habenular complex are involved in the pathology of schizophrenia and affective disorders. METHODS We characterized the number and density of calretinin-immunoreactive neurons in the lateral, medial, and dorsal subregions of the septal nuclei in three groups of subjects: healthy control subjects (N = 6), patients with schizophrenia (N = 10), and patients with affective disorders (N = 6). RESULTS Our mini-review of the combined role of calretinin and parvalbumin in schizophrenia and affective disorders summarizes 23 studies. We did not observe significant differences in the numbers of calretinin-immunoreactive neurons or neuronal densities in the lateral, medial, and dorsal septal nuclei of patients with schizophrenia or patients with affective disorders compared to healthy control subjects. CONCLUSIONS Most post-mortem investigations of patients with schizophrenia have indicated significant abnormalities of parvalbumin-immunoreactive neurons in various brain regions including the hippocampus, the anterior cingulate cortex, and the prefrontal cortex in schizophrenia. This study also provides an explanation from an evolutionary perspective for why calretinin is affected in schizophrenia.
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Affiliation(s)
- Ralf Brisch
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
| | - Hendrik Bielau
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany
| | - Arthur Saniotis
- School of Medicine, The University of Adelaide Adelaide, SA, Australia ; Institute of Evolutionary Medicine, University of Zurich Zurich, Switzerland
| | - Rainer Wolf
- Department of Psychiatry and Psychotherapy, Ruhr University Bochum Bochum, Germany
| | - Bernhard Bogerts
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany
| | - Dieter Krell
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany
| | - Johann Steiner
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany
| | - Katharina Braun
- Center for Behavioral Brain Sciences Magdeburg, Germany ; Department of Zoology/Developmental Neurobiology, Institute of Biology, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany
| | - Marta Krzyżanowska
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
| | - Maciej Krzyżanowski
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
| | - Zbigniew Jankowski
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
| | - Michał Kaliszan
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
| | - Hans-Gert Bernstein
- Department of Psychiatry and Psychotherapy, Otto-von-Guericke-University of Magdeburg Magdeburg, Germany
| | - Tomasz Gos
- Department of Forensic Medicine, Medical University of Gdańsk Gdańsk, Poland
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Enikolopov G, Overstreet-Wadiche L, Ge S. Viral and transgenic reporters and genetic analysis of adult neurogenesis. Cold Spring Harb Perspect Biol 2015; 7:a018804. [PMID: 26238354 DOI: 10.1101/cshperspect.a018804] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stem and progenitor cells of the developing and adult brain can be effectively identified and manipulated using reporter genes, introduced into transgenic reporter mouse lines or recombinant viruses. Such reporters rely on an ever-increasing variety of fluorescent proteins and a continuously expanding list of regulatory elements and of mouse lines engineered for cell- or time-specific recombination. An important extension of stem-cell-based genetic strategies is an opportunity to explore the properties of newly generated neurons and their contribution to synaptic plasticity. Here, we review available strategies for marking and quantifying various classes of stem and progenitor cells in the adult brain, genetically tracing their progeny, and studying the properties of stem cells and new neurons. We compare various experimental approaches to labeling and investigating stem cells and their progeny and discuss caveats and limitations inherent to each approach.
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Affiliation(s)
| | | | - Shaoyu Ge
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
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Nenov MN, Tempia F, Denner L, Dineley KT, Laezza F. Impaired firing properties of dentate granule neurons in an Alzheimer's disease animal model are rescued by PPARγ agonism. J Neurophysiol 2014; 113:1712-26. [PMID: 25540218 PMCID: PMC4359997 DOI: 10.1152/jn.00419.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Early cognitive impairment in Alzheimer's disease (AD) correlates with medial temporal lobe dysfunction, including two areas essential for memory formation: the entorhinal cortex and dentate gyrus (DG). In the Tg2576 animal model for AD amyloidosis, activation of the peroxisome proliferator-activated receptor-gamma (PPARγ) with rosiglitazone (RSG) ameliorates hippocampus-dependent cognitive impairment and restores aberrant synaptic activity at the entorhinal cortex to DG granule neuron inputs. It is unknown, however, whether intrinsic firing properties of DG granule neurons in these animals are affected by amyloid-β pathology and if they are sensitive to RSG treatment. Here, we report that granule neurons from 9-mo-old wild-type and Tg2576 animals can be segregated into two cell types with distinct firing properties and input resistance that correlate with less mature type I and more mature type II neurons. The DG type I cell population was greater than type II in wild-type littermates. In the Tg2576 animals, the type I and type II cell populations were nearly equal but could be restored to wild-type levels through cognitive enhancement with RSG. Furthermore, Tg2576 cell firing frequency and spike after depolarization were decreased in type I and increased in type II cells, both of which could also be restored to wild-type levels upon RSG treatment. That these parameters were restored by PPARγ activation emphasizes the therapeutic value of RSG against early AD cognitive impairment.
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Affiliation(s)
- Miroslav N Nenov
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas
| | - Filippo Tempia
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas
| | - Larry Denner
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, Texas; Center for Addiction Research, The University of Texas Medical Branch, Galveston, Texas; Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch, Galveston, Texas; and
| | - Kelly T Dineley
- Department of Neurology, The University of Texas Medical Branch, Galveston, Texas; Center for Addiction Research, The University of Texas Medical Branch, Galveston, Texas; Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch, Galveston, Texas; and
| | - Fernanda Laezza
- Department of Pharmacology and Toxicology, The University of Texas Medical Branch, Galveston, Texas; Center for Addiction Research, The University of Texas Medical Branch, Galveston, Texas; Mitchell Center for Neurodegenerative Diseases, The University of Texas Medical Branch, Galveston, Texas; and Center for Biomedical Engineering, The University of Texas Medical Branch, Galveston, Texas
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39
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Tiwari SK, Agarwal S, Seth B, Yadav A, Ray RS, Mishra VN, Chaturvedi RK. Inhibitory Effects of Bisphenol-A on Neural Stem Cells Proliferation and Differentiation in the Rat Brain Are Dependent on Wnt/β-Catenin Pathway. Mol Neurobiol 2014; 52:1735-1757. [PMID: 25381574 DOI: 10.1007/s12035-014-8940-1] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 10/13/2014] [Indexed: 02/07/2023]
Abstract
Neurogenesis, a process of generation of new neurons, occurs throughout the life in the hippocampus and sub-ventricular zone (SVZ). Bisphenol-A (BPA), an endocrine disrupter used as surface coating for packaged food cans, injures the developing and adult brain. However, the effects of BPA on neurogenesis and underlying cellular and molecular mechanism(s) are still unknown. Herein, we studied the effect(s) of prenatal and early postnatal exposure of low dose BPA on Wnt/β-catenin signaling pathway that controls different steps of neurogenesis such as neural stem cell (NSC) proliferation and neuronal differentiation. Pregnant rats were treated with 4, 40, and 400 μg BPA/kg body weight orally daily from gestational day 6 to postnatal day 21. Both in vivo and in vitro studies showed that BPA alters NSC proliferation and differentiation. BPA impaired NSC proliferation (5'-bromo-2'-deoxyuridine (BrdU(+)) and nestin(+) cells) and neuronal differentiation (BrdU/doublecortin(+) and BrdU/neuronal nuclei (NeuN(+)) cells) in the hippocampus and SVZ as compared to control. It significantly altered expression/protein levels of neurogenic genes and the Wnt pathway genes in the hippocampus. BPA reduced cellular β-catenin and p-GSK-3β levels and decreased β-catenin nuclear translocation, and cyclin-D1 and TCF/LEF promoter luciferase activity. Specific activation and blockage of the Wnt pathway suggested involvement of this pathway in BPA-mediated inhibition of neurogenesis. Further, blockage of GSK-3β activity by SB415286 and GSK-3β small interfering RNA (siRNA) attenuated BPA-induced downregulation of neurogenesis. Overall, these results suggest significant inhibitory effects of BPA on NSC proliferation and differentiation in the rat via the Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Shashi Kant Tiwari
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Swati Agarwal
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Brashket Seth
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Anuradha Yadav
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India.,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India
| | - Ratan Singh Ray
- Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.,Photobiology Division, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India
| | - Vijay Nath Mishra
- Department of Neurology, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Rajnish Kumar Chaturvedi
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80-MG Marg, Lucknow, Uttar Pradesh, India. .,Academy of Scientific and Innovative Research (AcSIR), New Delhi, India.
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40
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Pisar M, Forrest CM, Khalil OS, McNair K, Vincenten MC, Qasem S, Darlington LG, Stone TW. Modified neocortical and cerebellar protein expression and morphology in adult rats following prenatal inhibition of the kynurenine pathway. Brain Res 2014; 1576:1-17. [DOI: 10.1016/j.brainres.2014.06.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/12/2014] [Accepted: 06/13/2014] [Indexed: 10/25/2022]
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41
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Crescenzi R, DeBrosse C, Nanga RPR, Reddy S, Haris M, Hariharan H, Iba M, Lee VMY, Detre JA, Borthakur A, Reddy R. In vivo measurement of glutamate loss is associated with synapse loss in a mouse model of tauopathy. Neuroimage 2014; 101:185-92. [PMID: 25003815 DOI: 10.1016/j.neuroimage.2014.06.067] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Revised: 06/05/2014] [Accepted: 06/28/2014] [Indexed: 11/17/2022] Open
Abstract
Glutamate is the primary excitatory neurotransmitter in the brain, and is implicated in neurodegenerative diseases such as Alzheimer's disease (AD) and several other tauopathies. The current method for measuring glutamate in vivo is proton magnetic resonance spectroscopy ((1)H MRS), although it has poor spatial resolution and weak sensitivity to glutamate changes. In this study, we sought to measure the effect of tau pathology on glutamate levels throughout the brain of a mouse model of tauopathy using a novel magnetic resonance imaging (MRI) technique. We employed glutamate chemical exchange saturation transfer (GluCEST) imaging, which has been previously validated as a complimentary method for measuring glutamate levels with several important advantages over conventional (1)H MRS. We hypothesized that the regional changes in glutamate levels would correlate with histological measurements of pathology including pathological tau, synapse and neuron loss. Imaging and spectroscopy were carried out on tau transgenic mice with the P301S mutation (PS19, n=9) and their wild-type littermates (WT, n=8), followed by immunohistochemistry of their brain tissue. GluCEST imaging resolution allowed for sub-hippocampal analysis of glutamate. Glutamate was significantly decreased by 29% in the CA sub-region of the PS19 hippocampus, and by 15% in the thalamus, where synapse loss was also measured. Glutamate levels and synapse density remained high in the dentate gyrus sub-region of the hippocampus, where neurogenesis is known to occur. The further development of GluCEST imaging for preclinical applications will be valuable, as therapies are being tested in mouse models of tauopathy.
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Affiliation(s)
- Rachelle Crescenzi
- Department of Biochemistry and Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA; Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Catherine DeBrosse
- Department of Biochemistry and Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA; Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ravi Prakash Reddy Nanga
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Sanjana Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Mohammed Haris
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Michiyo Iba
- Center for Neurodegenerative Disease Research (CNDR), Department of Pathology & Lab Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Virginia M Y Lee
- Center for Neurodegenerative Disease Research (CNDR), Department of Pathology & Lab Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - John A Detre
- Center for Functional Neuroimaging (CFN), Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Arijitt Borthakur
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
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Valero J, Mastrella G, Neiva I, Sánchez S, Malva JO. Long-term effects of an acute and systemic administration of LPS on adult neurogenesis and spatial memory. Front Neurosci 2014; 8:83. [PMID: 24795557 PMCID: PMC4001049 DOI: 10.3389/fnins.2014.00083] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/01/2014] [Indexed: 12/11/2022] Open
Abstract
The cognitive reserve is the capacity of the brain to maintain normal performance while exposed to insults or ageing. Increasing evidences point to a role for the interaction between inflammatory conditions and cognitive reserve status during Alzheimer's disease (AD) progression. The production of new neurons along adult life can be considered as one of the components of the cognitive reserve. Interestingly, adult neurogenesis is decreased in mouse models of AD and following inflammatory processes. The aim of this work is to reveal the long-term impact of a systemic inflammatory event on memory and adult neurogenesis in wild type (WT) and triple transgenic mouse model of AD (3xTg-AD). Four month-old mice were intraperitoneally injected once with saline or lipopolysaccharide (LPS) and their performance on spatial memory analyzed with the Morris water maze (MWM) test 7 weeks later. Our data showed that a single intraperitoneal injection with LPS has a long-term impact in the production of hippocampal neurons. Consistently, LPS-treated WT mice showed less doublecortin-positive neurons, less synaptic contacts in newborn neurons, and decreased dendritic volume and complexity. These surprising observations were accompanied with memory deficits. 3xTg-AD mice showed a decrease in new neurons in the dentate gyrus compatible with, although exacerbated, the pattern observed in WT LPS-treated mice. In 3xTg-AD mice, LPS injection did not significantly affected the production of new neurons but reduced their number of synaptic puncta and impaired memory performance, when compared to the observations made in saline-treated 3xTg-AD mice. These data indicate that LPS treatment induces a long-term impairment on hippocampal neurogenesis and memory. Our results show that acute neuroinflammatory events influence the production of new hippocampal neurons, affecting the cognitive reserve and leading to the development of memory deficits associated to AD pathology.
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Affiliation(s)
- Jorge Valero
- Neuroprotection and Neurogenesis in Brain Repair Group, Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal ; Institute for Interdisciplinary Research, University of Coimbra Coimbra, Portugal
| | - Giorgia Mastrella
- Neuroprotection and Neurogenesis in Brain Repair Group, Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal ; International Master Degree in Neuroscience, Department of Life Sciences, "Università degli Studi di Trieste" Trieste, Italy
| | - Ismael Neiva
- Neuroprotection and Neurogenesis in Brain Repair Group, Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - Silvia Sánchez
- Neuroprotection and Neurogenesis in Brain Repair Group, Center for Neuroscience and Cell Biology, University of Coimbra Coimbra, Portugal
| | - João O Malva
- Faculty of Medicine, Institute for Biomedical Imaging and Life Sciences, University of Coimbra Coimbra, Portugal
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Takimoto N, Wang L, Itahashi M, Ogawa T, Segawa R, Hara S, Murakami T, Suzuki K, Shibutani M. Maternal single injection of N-methyl-N-nitrosourea to cause microcephaly in offspring induces transient aberration of hippocampal neurogenesis in mice. Toxicol Lett 2014; 226:20-7. [DOI: 10.1016/j.toxlet.2014.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 01/07/2014] [Accepted: 01/08/2014] [Indexed: 10/25/2022]
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Khalil OS, Pisar M, Forrest CM, Vincenten MCJ, Darlington LG, Stone TW. Prenatal inhibition of the kynurenine pathway leads to structural changes in the hippocampus of adult rat offspring. Eur J Neurosci 2014; 39:1558-71. [PMID: 24646396 PMCID: PMC4368408 DOI: 10.1111/ejn.12535] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/28/2014] [Accepted: 01/30/2014] [Indexed: 12/13/2022]
Abstract
Glutamate receptors for N-methyl-d-aspartate (NMDA) are involved in early brain development. The kynurenine pathway of tryptophan metabolism includes the NMDA receptor agonist quinolinic acid and the antagonist kynurenic acid. We now report that prenatal inhibition of the pathway in rats with 3,4-dimethoxy-N-[4-(3-nitrophenyl)thiazol-2-yl]benzenesulphonamide (Ro61-8048) produces marked changes in hippocampal neuron morphology, spine density and the immunocytochemical localisation of developmental proteins in the offspring at postnatal day 60. Golgi–Cox silver staining revealed decreased overall numbers and lengths of CA1 basal dendrites and secondary basal dendrites, together with fewer basal dendritic spines and less overall dendritic complexity in the basal arbour. Fewer dendrites and less complexity were also noted in the dentate gyrus granule cells. More neurons containing the nuclear marker NeuN and the developmental protein sonic hedgehog were detected in the CA1 region and dentate gyrus. Staining for doublecortin revealed fewer newly generated granule cells bearing extended dendritic processes. The number of neuron terminals staining for vesicular glutamate transporter (VGLUT)-1 and VGLUT-2 was increased by Ro61-8048, with no change in expression of vesicular GABA transporter or its co-localisation with vesicle-associated membrane protein-1. These data support the view that constitutive kynurenine metabolism normally plays a role in early embryonic brain development, and that interfering with it has profound consequences for neuronal structure and morphology, lasting into adulthood.
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Affiliation(s)
- Omari S Khalil
- Institute of Neuroscience and Psychology, West Medical Building, University of Glasgow, Glasgow, G12 8QQ, UK
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45
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Li H, Mao S, Wang H, Zen K, Zhang C, Li L. MicroRNA-29a modulates axon branching by targeting doublecortin in primary neurons. Protein Cell 2014; 5:160-9. [PMID: 24535747 PMCID: PMC3956970 DOI: 10.1007/s13238-014-0022-7] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 12/20/2013] [Indexed: 02/02/2023] Open
Abstract
MicroRNAs (miRNAs) are endogenously expressed small, non-coding transcripts that regulate protein expression. Substantial evidences suggest that miRNAs are enriched in central nervous system, where they are hypothesized to play pivotal roles during neural development. In the present study, we analyzed miRNAs expression in mice cerebral cortex and hippocampus at different developmental stages and found miR-29a increased dramatically at postnatal stages. In addition, we provided strong evidences that miR-29a is enriched in mature neurons both in vitro and in vivo. Further investigation demonstrated that the activation of glutamate receptors induced endogenous miR-29a level in primary neurons. Moreover, we showed that miR-29a directly regulated its target protein Doublecortin (DCX) expression, which further modulated axon branching in primary culture. Together, our results suggested that miR-29a play an important role in neuronal development of mice cerebrum.
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Affiliation(s)
- Hanqin Li
- Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University School of Life Sciences, Nanjing, 210093, China
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In contrast to many other mammals, cetaceans have relatively small hippocampi that appear to lack adult neurogenesis. Brain Struct Funct 2013; 220:361-83. [PMID: 24178679 DOI: 10.1007/s00429-013-0660-1] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/15/2013] [Indexed: 12/16/2022]
Abstract
The hippocampus is essential for the formation and retrieval of memories and is a crucial neural structure sub-serving complex cognition. Adult hippocampal neurogenesis, the birth, migration and integration of new neurons, is thought to contribute to hippocampal circuit plasticity to augment function. We evaluated hippocampal volume in relation to brain volume in 375 mammal species and examined 71 mammal species for the presence of adult hippocampal neurogenesis using immunohistochemistry for doublecortin, an endogenous marker of immature neurons that can be used as a proxy marker for the presence of adult neurogenesis. We identified that the hippocampus in cetaceans (whales, dolphins and porpoises) is both absolutely and relatively small for their overall brain size, and found that the mammalian hippocampus scaled as an exponential function in relation to brain volume. In contrast, the amygdala was found to scale as a linear function of brain volume, but again, the relative size of the amygdala in cetaceans was small. The cetacean hippocampus lacks staining for doublecortin in the dentate gyrus and thus shows no clear signs of adult hippocampal neurogenesis. This lack of evidence of adult hippocampal neurogenesis, along with the small hippocampus, questions current assumptions regarding cognitive abilities associated with hippocampal function in the cetaceans. These anatomical features of the cetacean hippocampus may be related to the lack of postnatal sleep, causing a postnatal cessation of hippocampal neurogenesis.
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Sarnat HB. Clinical neuropathology practice guide 5-2013: markers of neuronal maturation. Clin Neuropathol 2013; 32:340-69. [PMID: 23883617 PMCID: PMC3796735 DOI: 10.5414/np300638] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 08/23/2013] [Indexed: 11/18/2022] Open
Abstract
This review surveys immunocytochemical and histochemical markers of neuronal lineage for application to tissue sections of fetal and neonatal brain. They determine maturation of individual nerve cells as the tissue progresses to mature architecture. From a developmental perspective, neuronal markers are all about timing. These diverse cellular labels may be classified in two ways: 1) time of onset of expression (early; intermediate; late); 2) labeling of subcellular structures or metabolic functions (nucleoproteins; synaptic vesicle proteins; enolases; cytoskeletal elements; calcium-binding; nucleic acids; mitochondria). Apart from these positive markers of maturation, other negative markers are expressed in primitive neuroepithelial cells and early stages of neuroblast maturation, but no longer are demonstrated after initial stages of maturation. These examinations are relevant for studies of normal neuroembryology at the cellular level. In fetal and perinatal neuropathology they provide control criteria for application to malformations of the brain, inborn metabolic disorders and acquired fetal insults in which neuroblastic maturation may be altered. Disorders, in which cells differentiate abnormally, as in tuberous sclerosis and hemimegalencephaly, pose another yet aspect of mixed cellular lineage. The measurement in living patients, especially neonates, of serum and CSF levels of enolases, chromogranins and S-100 proteins as biomarkers of brain damage may potentially be correlated with their corresponding tissue markers at autopsy in infants who do not survive. The neuropathological markers here described can be performed in ordinary hospital laboratories, not just research facilities, and offer another dimension of diagnostic precision in interpreting abnormally developed fetal and postnatal brains.
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Functional implications of hippocampal adult neurogenesis in intellectual disabilities. Amino Acids 2013; 45:113-31. [DOI: 10.1007/s00726-013-1489-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 03/15/2013] [Indexed: 12/19/2022]
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