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Chaker Z, Segalada C, Kretz JA, Acar IE, Delgado AC, Crotet V, Moor AE, Doetsch F. Pregnancy-responsive pools of adult neural stem cells for transient neurogenesis in mothers. Science 2023; 382:958-963. [PMID: 37995223 DOI: 10.1126/science.abo5199] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 10/05/2023] [Indexed: 11/25/2023]
Abstract
Adult neural stem cells (NSCs) contribute to lifelong brain plasticity. In the adult mouse ventricular-subventricular zone, NSCs are heterogeneous and, depending on their location in the niche, give rise to different subtypes of olfactory bulb (OB) interneurons. Here, we show that multiple regionally distinct NSCs, including domains that are usually quiescent, are recruited on different gestation days during pregnancy. Synchronized activation of these adult NSC pools generates transient waves of short-lived OB interneurons, especially in layers with less neurogenesis under homeostasis. Using spatial transcriptomics, we identified molecular markers of pregnancy-associated interneurons and showed that some subsets are temporarily needed for own pup recognition. Thus, pregnancy triggers transient yet behaviorally relevant neurogenesis, highlighting the physiological relevance of adult stem cell heterogeneity.
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Affiliation(s)
- Zayna Chaker
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | | | - Jonas A Kretz
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Ilhan E Acar
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Ana C Delgado
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Valerie Crotet
- Biozentrum, University of Basel, 4056 Basel, Switzerland
| | - Andreas E Moor
- Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland
| | - Fiona Doetsch
- Biozentrum, University of Basel, 4056 Basel, Switzerland
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2
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Su Z, Wang Z, Lindtner S, Yang L, Shang Z, Tian Y, Guo R, You Y, Zhou W, Rubenstein JL, Yang Z, Zhang Z. Dlx1/2-dependent expression of Meis2 promotes neuronal fate determination in the mammalian striatum. Development 2022; 149:dev200035. [PMID: 35156680 PMCID: PMC8918808 DOI: 10.1242/dev.200035] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/04/2022] [Indexed: 12/16/2022]
Abstract
The striatum is a central regulator of behavior and motor function through the actions of D1 and D2 medium-sized spiny neurons (MSNs), which arise from a common lateral ganglionic eminence (LGE) progenitor. The molecular mechanisms of cell fate specification of these two neuronal subtypes are incompletely understood. Here, we found that deletion of murine Meis2, which is highly expressed in the LGE and derivatives, led to a large reduction in striatal MSNs due to a block in their differentiation. Meis2 directly binds to the Zfp503 and Six3 promoters and is required for their expression and specification of D1 and D2 MSNs, respectively. Finally, Meis2 expression is regulated by Dlx1/2 at least partially through the enhancer hs599 in the LGE subventricular zone. Overall, our findings define a pathway in the LGE whereby Dlx1/2 drives expression of Meis2, which subsequently promotes the fate determination of striatal D1 and D2 MSNs via Zfp503 and Six3.
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Affiliation(s)
- Zihao Su
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Ziwu Wang
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Susan Lindtner
- Department of Psychiatry, Nina Ireland Laboratory of Developmental Neurobiology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Lin Yang
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Zicong Shang
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Yu Tian
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Rongliang Guo
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Yan You
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Wenhao Zhou
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - John L. Rubenstein
- Department of Psychiatry, Nina Ireland Laboratory of Developmental Neurobiology, UCSF Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Zhengang Yang
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
| | - Zhuangzhi Zhang
- Key Laboratory of Birth Defects, Children's Hospital of Fudan University, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, 138 Yi Xue Yuan Road, Shanghai 200032, China
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3
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Jafari S, Henriksson J, Yan H, Alenius M. Stress and odorant receptor feedback during a critical period after hatching regulates olfactory sensory neuron differentiation in Drosophila. PLoS Biol 2021; 19:e3001101. [PMID: 33793547 PMCID: PMC8043390 DOI: 10.1371/journal.pbio.3001101] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 04/13/2021] [Accepted: 03/02/2021] [Indexed: 11/19/2022] Open
Abstract
Here, we reveal that the regulation of Drosophila odorant receptor (OR) expression during the pupal stage is permissive and imprecise. We found that directly after hatching an OR feedback mechanism both directs and refines OR expression. We demonstrate that, as in mice, dLsd1 and Su(var)3-9 balance heterochromatin formation to direct OR expression. We show that the expressed OR induces dLsd1 and Su(var)3-9 expression, linking OR level and possibly function to OR expression. OR expression refinement shows a restricted duration, suggesting that a gene regulatory critical period brings olfactory sensory neuron differentiation to an end. Consistent with a change in differentiation, stress during the critical period represses dLsd1 and Su(var)3-9 expression and makes the early permissive OR expression permanent. This induced permissive gene regulatory state makes OR expression resilient to stress later in life. Hence, during a critical period OR feedback, similar to in mouse OR selection, defines adult OR expression in Drosophila.
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Affiliation(s)
- Shadi Jafari
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Johan Henriksson
- Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Hua Yan
- Department of Biology, University of Florida, Gainesville, Florida, United States of America
| | - Mattias Alenius
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
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Sokolov AM, Holmberg JC, Feliciano DM. The amino acid transporter Slc7a5 regulates the mTOR pathway and is required for granule cell development. Hum Mol Genet 2020; 29:3003-3013. [PMID: 32821949 PMCID: PMC7645712 DOI: 10.1093/hmg/ddaa186] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/03/2020] [Accepted: 08/15/2020] [Indexed: 12/11/2022] Open
Abstract
Pathogenic mutations in the solute carrier family 7 member 5 (SLC7A5) gene, which encodes an amino acid transporter cause microcephaly and seizures, yet the mechanisms responsible for these phenotypes are unclear. Models have demonstrated that Slc7a5 deletion is embryonic lethal and that these embryos lack a fully formed telencephalon. This phenotype is similar to that of mammalian target of rapamycin (mTOR) protein kinase deletion or mTOR inhibition. Notably, in many cells, Slc7a5 import of amino acids is required to maintain mTOR activity. Slc7a5 is present within neurogenic regions during embryogenesis, is found in cultured neurons and can modulate neuronal electrophysiological properties. However, Slc7a5 is also highly expressed within endothelial cells of the blood-brain barrier where removal in conditional mice leads to severe behavioral defects and non-cell autonomous changes in neurons. Therefore, the extent that neural Slc7a5 is required for development is unclear. Here, subventricular zone neural stem cells that generate olfactory bulb granule cell neurons were electroporated with SLC7A5 or Slc7a5 short hairpin RNA encoding plasmids. Although early phases of neural development were unaltered, Slc7a5 knockdown effected late phases of GC dendrite maturation and survival. Slc7a5 knockdown also decreased mTOR pathway activity. Ras homolog enriched in brain, an mTOR activator, rescued the effect of Slc7a5 knockdown on mTOR pathway activity and dendrite arbors. The data presented here demonstrate that Slc7a5 is required for GC mTOR pathway activity, maturation and survival, which may help explain why Slc7a5 mutations prevent normal brain development and function.
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Affiliation(s)
- Aidan M Sokolov
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - Jennie C Holmberg
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
| | - David M Feliciano
- Department of Biological Sciences, Clemson University, Clemson, SC 29634-0314, USA
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5
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Hogan AVC, Watanabe A, Balanoff AM, Bever GS. Comparative growth in the olfactory system of the developing chick with considerations for evolutionary studies. J Anat 2020; 237:225-240. [PMID: 32314400 PMCID: PMC7369194 DOI: 10.1111/joa.13197] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 02/17/2020] [Accepted: 03/10/2020] [Indexed: 12/26/2022] Open
Abstract
Despite the long-held assumption that olfaction plays a relatively minor role in the behavioral ecology of birds, crown-group avians exhibit marked phylogenetic variation in the size and form of the olfactory apparatus. As part of a larger effort to better understand the role of olfaction and olfactory tissues in the evolution and development of the avian skull, we present the first quantitative analysis of ontogenetic scaling between olfactory features [olfactory bulbs (OBs) and olfactory turbinates] and neighboring structures (cerebrum, total brain, respiratory turbinates) based on the model organism Gallus gallus. The OB develops under the predictions of a concerted evolutionary model with rapid early growth that is quickly overcome by the longer, sustained growth of the larger cerebrum. A similar pattern is found in the nasal cavity where the morphologically simple (non-scrolled) olfactory turbinates appear and mature early, with extended growth characterizing the larger and scrolled respiratory turbinates. Pairwise regressions largely recover allometric relationships among the examined structures, with a notable exception being the isometric trajectory of the OB and olfactory turbinate. Their parallel growth suggests a unique regulatory pathway that is likely driven by the morphogenesis of the olfactory nerve, which serves as a structural bridge between the two features. Still, isometry was not necessarily expected given that the olfactory epithelium covers more than just the turbinate. These data illuminate a number of evolutionary hypotheses that, moving forward, should inform tradeoffs and constraints between the olfactory and neighboring systems in the avian head.
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Affiliation(s)
- Aneila V. C. Hogan
- Center for Functional Anatomy and EvolutionJohns Hopkins University School of MedicineBaltimoreMDUSA
| | - Akinobu Watanabe
- Department of AnatomyNew York Institute of Technology College of Osteopathic MedicineNew YorkNYUSA
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
- Life Sciences DepartmentVertebrates DivisionNatural History MuseumLondonUK
| | - Amy M. Balanoff
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of Psychological and Brain SciencesJohns Hopkins UniversityBaltimoreMDUSA
| | - Gabriel S. Bever
- Center for Functional Anatomy and EvolutionJohns Hopkins University School of MedicineBaltimoreMDUSA
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
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6
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Deryckere A, Stappers E, Dries R, Peyre E, van den Berghe V, Conidi A, Zampeta FI, Francis A, Bresseleers M, Stryjewska A, Vanlaer R, Maas E, Smal IV, van IJcken WFJ, Grosveld FG, Nguyen L, Huylebroeck D, Seuntjens E. Multifaceted actions of Zeb2 in postnatal neurogenesis from the ventricular-subventricular zone to the olfactory bulb. Development 2020; 147:dev184861. [PMID: 32253238 DOI: 10.1242/dev.184861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 03/23/2020] [Indexed: 03/01/2024]
Abstract
The transcription factor Zeb2 controls fate specification and subsequent differentiation and maturation of multiple cell types in various embryonic tissues. It binds many protein partners, including activated Smad proteins and the NuRD co-repressor complex. How Zeb2 subdomains support cell differentiation in various contexts has remained elusive. Here, we studied the role of Zeb2 and its domains in neurogenesis and neural differentiation in the young postnatal ventricular-subventricular zone (V-SVZ), in which neural stem cells generate olfactory bulb-destined interneurons. Conditional Zeb2 knockouts and separate acute loss- and gain-of-function approaches indicated that Zeb2 is essential for controlling apoptosis and neuronal differentiation of V-SVZ progenitors before and after birth, and we identified Sox6 as a potential downstream target gene of Zeb2. Zeb2 genetic inactivation impaired the differentiation potential of the V-SVZ niche in a cell-autonomous fashion. We also provide evidence that its normal function in the V-SVZ also involves non-autonomous mechanisms. Additionally, we demonstrate distinct roles for Zeb2 protein-binding domains, suggesting that Zeb2 partners co-determine neuronal output from the mouse V-SVZ in both quantitative and qualitative ways in early postnatal life.
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Affiliation(s)
- Astrid Deryckere
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Elke Stappers
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Ruben Dries
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Elise Peyre
- GIGA-Stem Cells and GIGA-Neurosciences, Liège University, Liège 4000, Belgium
| | - Veronique van den Berghe
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, and MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, UK
| | - Andrea Conidi
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - F Isabella Zampeta
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Annick Francis
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Marjolein Bresseleers
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Agata Stryjewska
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
| | - Ria Vanlaer
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
| | - Elke Maas
- Department of Cardiovascular Sciences, Center for Molecular and Vascular Biology, KU Leuven, Leuven 3000, Belgium
| | - Ihor V Smal
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
- Department of Molecular Genetics, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Wilfred F J van IJcken
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
- Center for Biomics-Genomics, Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Frank G Grosveld
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Laurent Nguyen
- GIGA-Stem Cells and GIGA-Neurosciences, Liège University, Liège 4000, Belgium
| | - Danny Huylebroeck
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
- Department of Cell Biology, Erasmus University Medical Center, Rotterdam 3015 CN, The Netherlands
| | - Eve Seuntjens
- Laboratory of Developmental Neurobiology, Department of Biology, KU Leuven, Leuven 3000, Belgium
- Laboratory of Molecular Biology (Celgen), Department of Development and Regeneration, KU Leuven, Leuven 3000, Belgium
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Sánchez-González R, Figueres-Oñate M, Ojalvo-Sanz AC, López-Mascaraque L. Cell Progeny in the Olfactory Bulb After Targeting Specific Progenitors with Different UbC-StarTrack Approaches. Genes (Basel) 2020; 11:genes11030305. [PMID: 32183100 PMCID: PMC7140809 DOI: 10.3390/genes11030305] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 03/11/2020] [Accepted: 03/11/2020] [Indexed: 02/07/2023] Open
Abstract
The large phenotypic variation in the olfactory bulb may be related to heterogeneity in the progenitor cells. Accordingly, the progeny of subventricular zone (SVZ) progenitor cells that are destined for the olfactory bulb is of particular interest, specifically as there are many facets of these progenitors and their molecular profiles remain unknown. Using modified StarTrack genetic tracing strategies, specific SVZ progenitor cells were targeted in E12 mice embryos, and the cell fate of these neural progenitors was determined in the adult olfactory bulb. This study defined the distribution and the phenotypic diversity of olfactory bulb interneurons from specific SVZ-progenitor cells, focusing on their spatial pallial origin, heterogeneity, and genetic profile.
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Taroc EZM, Naik AS, Lin JM, Peterson NB, Keefe DL, Genis E, Fuchs G, Balasubramanian R, Forni PE. Gli3 Regulates Vomeronasal Neurogenesis, Olfactory Ensheathing Cell Formation, and GnRH-1 Neuronal Migration. J Neurosci 2020; 40:311-326. [PMID: 31767679 PMCID: PMC6948949 DOI: 10.1523/jneurosci.1977-19.2019] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/18/2019] [Accepted: 11/17/2019] [Indexed: 12/20/2022] Open
Abstract
During mammalian development, gonadotropin-releasing-hormone-1 neurons (GnRH-1ns) migrate from the developing vomeronasal organ (VNO) into the brain asserting control of pubertal onset and fertility. Recent data suggest that correct development of the olfactory ensheathing cells (OEC) is imperative for normal GnRH-1 neuronal migration. However, the full ensemble of molecular pathways that regulate OEC development remains to be fully deciphered. Loss-of-function of the transcription factor Gli3 is known to disrupt olfactory development, however, if Gli3 plays a role in GnRH-1 neuronal development is unclear. By analyzing Gli3 extra-toe mutants (Gli3Xt/Xt), we found that Gli3 loss-of-function compromises the onset of achaete-scute family bHLH transcription factor 1 (Ascl-1)+ vomeronasal progenitors and the formation of OEC in the nasal mucosa. Surprisingly, GnRH-1 neurogenesis was intact in Gli3Xt/Xt mice but they displayed significant defects in GnRH-1 neuronal migration. In contrast, Ascl-1null mutants showed reduced neurogenesis for both vomeronasal and GnRH-1ns but less severe defects in OEC development. These observations suggest that Gli3 is critical for OEC development in the nasal mucosa and subsequent GnRH-1 neuronal migration. However, the nonoverlapping phenotypes between Ascl-1 and Gli3 mutants indicate that Ascl-1, while crucial for GnRH-1 neurogenesis, is not required for normal OEC development. Because Kallmann syndrome (KS) is characterized by abnormal GnRH-1ns migration, we examined whole-exome sequencing data from KS subjects. We identified and validated a GLI3 loss-of-function variant in a KS individual. These findings provide new insights into GnRH-1 and OECs development and demonstrate that human GLI3 mutations contribute to KS etiology.SIGNIFICANCE STATEMENT The transcription factor Gli3 is necessary for correct development of the olfactory system. However, if Gli3 plays a role in controlling GnRH-1 neuronal development has not been addressed. We found that Gli3 loss-of-function compromises the onset of Ascl-1+ vomeronasal progenitors, formation of olfactory ensheathing cells in the nasal mucosa, and impairs GnRH-1 neuronal migration to the brain. By analyzing Ascl-1null mutants we dissociated the neurogenic defects observed in Gli3 mutants from lack of olfactory ensheathing cells in the nasal mucosa, moreover, we discovered that Ascl-1 is necessary for GnRH-1 ontogeny. Analyzing human whole-exome sequencing data, we identified a GLI3 loss-of-function variant in a KS individual. Our data suggest that GLI3 is a candidate gene contributing to KS etiology.
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Affiliation(s)
- Ed Zandro M Taroc
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - Ankana S Naik
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - Jennifer M Lin
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - Nicolas B Peterson
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - David L Keefe
- Harvard Reproductive Sciences Center and The Reproductive Endocrine Unit of the Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Elizabet Genis
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - Gabriele Fuchs
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
| | - Ravikumar Balasubramanian
- Harvard Reproductive Sciences Center and The Reproductive Endocrine Unit of the Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts 02114
| | - Paolo E Forni
- Department of Biological Sciences; The RNA Institute, and the Center for Neuroscience Research; University at Albany, State University of New York, Albany, New York 12222, and
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9
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Abrahão VP, Pastana M, Marinho M. On a remarkable sexual dimorphic trait in the Characiformes related to the olfactory organ and description of a new miniature species of Tyttobrycon Géry (Characiformes: Characidae). PLoS One 2019; 14:e0226130. [PMID: 31851726 PMCID: PMC6919584 DOI: 10.1371/journal.pone.0226130] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/19/2019] [Indexed: 11/19/2022] Open
Abstract
Among the order Characiformes, secondary sexual dimorphism is commonly associated to the occurrence of bony hooks on fins, shape and length of the dorsal and anal fins, and sexual dichromatism. The analysis of a new miniature Characidae species of the genus Tyttobrycon, described herein, yielded to the discovery of a sexually dimorphic trait related to nostril aperture and number of olfactory lamellae. In this type of dimorphism, mature males present larger nostril aperture and higher number of olfactory lamella than females. A dimorphic olfactory organ is for the first time recorded and described for a member of the Characiformes. Gross morphology and development of brain and peripheral olfactory organ of Tyttobrycon sp. n. are described and compared to other species of Characidae. It is hypothesized that such dimorphic trait is related to male-male detection during cohort competition in small characids. The new species of Tyttobrycon is diagnosed from its congeners by the number of branched anal-fin rays (19-21) and the absence of a caudal-peduncle blotch. It occurs in a small tributary of Rio Madeira basin, near to the limit between Brazil and Bolivia, Acre State, Brazil.
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Affiliation(s)
- Vitor Pimenta Abrahão
- Museu de Zoologia da Universidade de São Paulo, São Paulo, SP, Brazil
- Programa de Pós-Graduação em Biodiversidade e Evolução, Instituto de Biologia, Universidade Federal da Bahia, Rua Barão de Geremoabo, Ondina, Salvador, BA, Brazil
| | - Murilo Pastana
- Museu de Zoologia da Universidade de São Paulo, São Paulo, SP, Brazil
| | - Manoela Marinho
- Museu de Zoologia da Universidade de São Paulo, São Paulo, SP, Brazil
- Laboratório de Sistemática e Morfologia de Peixes, Departamento de Sistemática e Ecologia/CCEN, Universidade Federal da Paraíba, Campus I, João Pessoa, PB, Brazil
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10
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Abstract
This chapter focuses on the development of the human olfactory system. In this system, function does not require full neuroanatomical maturity. Thus, discrimination of odorous molecules, including a number within the mother's diet, occurs in amniotic fluid after 28-30 weeks of gestation, at which time the olfactory bulbs are identifiable by MRI. Hypoplasia/aplasia of the bulbs is documented in the third trimester and postnatally. Interestingly, olfactory axons project from the nasal epithelium to the telencephalon before formation of the olfactory bulbs and lack a peripheral ganglion, but the synaptic glomeruli of the future olfactory bulb serves this function. Histologic lamination of the olfactory bulb is present by 14 weeks, but maturation remains incomplete at term for neuronal differentiation, synaptogenesis, myelination, and persistence of the normal transitory fetal ventricular recess. Myelination occurs postnatally. Although olfaction is the only sensory system without direct thalamic projections, the olfactory bulb and anterior olfactory nucleus are, in effect, thalamic surrogates. For example, many dendro-dendritic synapses occur within the bulb between GABAergic granular neurons and periglomerular neurons. Moreover, bulbar synaptic glomeruli are analogous to peripheral ganglia of other sensory cranial nerves. The olfactory tract contains much gray as well as white matter. The olfactory epithelium and bulb both incorporate progenitor cells at all ages. Diverse malformations of the olfactory bulb can be detected by clinical examination, imaging, and neuropathology; indeed, olfactory reflexes of the neonate can be reliably tested. We recommend that such testing be routine in the neonatal neurologic examination, especially in children with brain malformations, endocrinopathies, chromosomopathies, genetic/metabolic disorders, and perinatal hypoxic/ischemic encephalopathy.
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Affiliation(s)
- Harvey B Sarnat
- Department of Paediatrics, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Pathology and Laboratory Medicine (Neuropathology), University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada.
| | - Laura Flores-Sarnat
- Department of Paediatrics, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada; Department of Clinical Neurosciences, University of Calgary Cumming School of Medicine and Alberta Children's Hospital Research Institute, Calgary, AB, Canada
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11
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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12
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Pandolfi EC, Hoffmann HM, Schoeller EL, Gorman MR, Mellon PL. Haploinsufficiency of SIX3 Abolishes Male Reproductive Behavior Through Disrupted Olfactory Development, and Impairs Female Fertility Through Disrupted GnRH Neuron Migration. Mol Neurobiol 2018; 55:8709-8727. [PMID: 29589282 PMCID: PMC6156938 DOI: 10.1007/s12035-018-1013-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/16/2018] [Indexed: 12/17/2022]
Abstract
Mating behavior in males and females is dependent on olfactory cues processed through both the main olfactory epithelium (MOE) and the vomeronasal organ (VNO). Signaling through the MOE is critical for the initiation of male mating behavior, and the loss of MOE signaling severely compromises this comportment. Here, we demonstrate that dosage of the homeodomain gene Six3 affects the degree of development of MOE but not the VNO. Anomalous MOE development in Six3 heterozygote mice leads to hyposmia, specifically disrupting male mounting behavior by impairing detection of volatile female estrus pheromones. Six3 is highly expressed in the MOE, main olfactory bulb (MOB), and hypothalamus; all regions essential in the proper migration of the gonadotropin-releasing hormone (GnRH) neurons, a key reproductive neuronal population that migrates along olfactory axons from the developing nose into the brain. Interestingly, we find that the reduction in Six3 expression in Six3 heterozygote mice compromises development of the MOE and MOB, resulting in mis-migration of GnRH neurons due to improper olfactory axon targeting. This reduction in the hypothalamic GnRH neuron population, by 45% in adulthood, leads to female subfertility, but does not impact male hormone levels, suggesting that male infertility is not related to GnRH neuron numbers, but exclusively linked to abnormal olfaction. We here determine that Six3 is haploinsufficient for MOE development, GnRH neuron migration, and fertility, and represents a novel candidate gene for Kallmann syndrome, a form of inherited infertility.
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Affiliation(s)
- Erica C Pandolfi
- Department of Reproductive Medicine, Center for Reproductive Science and Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0674, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Hanne M Hoffmann
- Department of Reproductive Medicine, Center for Reproductive Science and Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0674, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Erica L Schoeller
- Department of Reproductive Medicine, Center for Reproductive Science and Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0674, USA
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Michael R Gorman
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, 92093, USA
- Department of Psychology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Pamela L Mellon
- Department of Reproductive Medicine, Center for Reproductive Science and Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0674, USA.
- Center for Circadian Biology, University of California, San Diego, La Jolla, CA, 92093, USA.
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13
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Heerema JL, Jackman KW, Miliano RC, Li L, Zaborniak TSM, Veldhoen N, van Aggelen G, Parker WJ, Pyle GG, Helbing CC. Behavioral and molecular analyses of olfaction-mediated avoidance responses of Rana (Lithobates) catesbeiana tadpoles: Sensitivity to thyroid hormones, estrogen, and treated municipal wastewater effluent. Horm Behav 2018; 101:85-93. [PMID: 28964734 DOI: 10.1016/j.yhbeh.2017.09.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 09/25/2017] [Accepted: 09/25/2017] [Indexed: 10/18/2022]
Abstract
Olfaction is critical for survival, facilitating predator avoidance and food location. The nature of the olfactory system changes during amphibian metamorphosis as the aquatic herbivorous tadpole transitions to a terrestrial, carnivorous frog. Metamorphosis is principally dependent on the action of thyroid hormones (THs), l-thyroxine (T4) and 3,5,3'-triiodothyronine (T3), yet little is known about their influence on olfaction during this phase of postembryonic development. We exposed Taylor Kollros stage I-XIII Rana (Lithobates) catesbeiana tadpoles to physiological concentrations of T4, T3, or 17-beta-estradiol (E2) for 48h and evaluated a predator cue avoidance response. The avoidance response in T3-exposed tadpoles was abolished while T4- or E2-exposed tadpoles were unaffected compared to control tadpoles. qPCR analyses on classic TH-response gene transcripts (thra, thrb, and thibz) in the olfactory epithelium demonstrated that, while both THs produced molecular responses, T3 elicited greater responses than T4. Municipal wastewater feed stock was spiked with a defined pharmaceutical and personal care product (PPCP) cocktail and treated with an anaerobic membrane bioreactor (AnMBR). Despite substantially reduced PPCP levels, exposure to this effluent abolished avoidance behavior relative to AnMBR effluent whose feed stock was spiked with vehicle. Thibz transcript levels increased upon exposure to either effluent indicating TH mimic activity. The present work is the first to demonstrate differential TH responsiveness of the frog tadpole olfactory system with both behavioral and molecular alterations. A systems-based analysis is warranted to further elucidate the mechanism of action on the olfactory epithelium and identify further molecular bioindicators linked to behavioral response disruption.
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Affiliation(s)
- Jody L Heerema
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Kevin W Jackman
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Rachel C Miliano
- Environment Canada, Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2, Canada
| | - Linda Li
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Tristan S M Zaborniak
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Nik Veldhoen
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Graham van Aggelen
- Environment Canada, Pacific Environmental Science Centre, 2645 Dollarton Highway, North Vancouver, British Columbia V7H 1V2, Canada
| | - Wayne J Parker
- Department of Civil and Environmental Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada
| | - Caren C Helbing
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada.
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14
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Wallace JL, Wienisch M, Murthy VN. Development and Refinement of Functional Properties of Adult-Born Neurons. Neuron 2017; 96:883-896.e7. [PMID: 29056299 PMCID: PMC5789450 DOI: 10.1016/j.neuron.2017.09.039] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 07/26/2017] [Accepted: 09/22/2017] [Indexed: 01/21/2023]
Abstract
New neurons appear only in a few regions of the adult mammalian brain and become integrated into existing circuits. Little is known about the functional development of individual neurons in vivo. We examined the functional life history of adult-born granule cells (abGCs) in the olfactory bulb using multiphoton imaging in awake and anesthetized mice. We found that abGCs can become responsive to odorants soon after they arrive in the olfactory bulb. Tracking identified abGCs over weeks revealed that the robust and broadly tuned responses of most newly arrived abGCs gradually become more selective over a period of ∼3 weeks, but a small fraction achieves broader tuning with maturation. Enriching the olfactory environment of mice prolonged the period over which abGCs were strongly and broadly responsive to odorants. Our data offer direct support for rapid integration of adult-born neurons into existing circuits, followed by experience-dependent refinement of their functional connectivity.
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Affiliation(s)
- Jenelle L Wallace
- Molecules, Cells, and Organisms training program, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Martin Wienisch
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
| | - Venkatesh N Murthy
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA; Department of Molecular & Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
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15
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Chavez GG, Taylor G, Garaliene J, Richardson GP, Korneev SA. The temporal expression profile of a Nos3-related natural antisense RNA in the brain suggests a possible role in neurogenesis. Nitric Oxide 2017; 71:27-31. [PMID: 29031735 PMCID: PMC5714617 DOI: 10.1016/j.niox.2017.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 09/22/2017] [Accepted: 10/11/2017] [Indexed: 12/15/2022]
Abstract
Experimental work over the past several years has revealed an unexpected abundance of long natural antisense transcripts (NATs) in eukaryotic species. In light of the proposed role of such RNA molecules in the regulation of gene expression in the brain, attention is now focused on specific examples of neuronal NATs. Of particular interest are NATs that are complementary to mRNAs encoding nitric oxide synthase (NOS), the enzyme responsible for production of the important gaseous neurotransmitter nitric oxide (NO). Here we study the temporal expression profile of murine Nos3as NAT in the brain. Notably, Nos3as NAT is known to act as a negative regulator of Nos3 gene expression. The results of our quantitative analysis reveal differential expression of Nos3as NAT during embryonic and post-embryonic stages of development of the brain. Also, they show that the low levels of Nos3as NAT coincides with active neurogenesis. In addition we report on an inverse correlation between the relative expression level of Nos3as NAT and the level of Nos3 protein. Thus our data raise the hypothesis that the Nos3as NAT regulates neurogenesis through suppression of Nos3 gene activity. This idea is further supported by experiments conducted on the olfactory bulbs and cultured neuroblastoma cells. Nos3as NAT and Nos3 mRNA are differentially expressed during mouse brain development and aging. Low levels of Nos3as NAT coincides with active neurogenesis. There is an inverse correlation between the expression level of Nos3as NAT and the level of Nos3 protein in the brain. Neuronal differentiation of cultured neuroblastoma cells is associated with up-regulation of Nos3as NAT. Nos3as NAT may be involved in controlling both embryonic and adult neurogenesis.
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Affiliation(s)
- Gabriela G Chavez
- Sussex Neuroscience, School of Life Science, University of Sussex, Brighton, BN1 9QG, UK
| | - Gabriella Taylor
- Sussex Neuroscience, School of Life Science, University of Sussex, Brighton, BN1 9QG, UK
| | - Jekaterina Garaliene
- Sussex Neuroscience, School of Life Science, University of Sussex, Brighton, BN1 9QG, UK
| | - Guy P Richardson
- Sussex Neuroscience, School of Life Science, University of Sussex, Brighton, BN1 9QG, UK
| | - Sergei A Korneev
- Sussex Neuroscience, School of Life Science, University of Sussex, Brighton, BN1 9QG, UK.
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16
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Guerrero-Cazares H, Lavell E, Chen L, Schiapparelli P, Lara-Velazquez M, Capilla-Gonzalez V, Drummond G, Clements AC, Noiman L, Thaler K, Burke A, Quiñones-Hinojosa A. Brief Report: Robo1 Regulates the Migration of Human Subventricular Zone Neural Progenitor Cells During Development. Stem Cells 2017; 35:1860-1865. [PMID: 28406573 PMCID: PMC5484745 DOI: 10.1002/stem.2628] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/08/2017] [Accepted: 03/28/2017] [Indexed: 01/19/2023]
Abstract
Human neural progenitor cell (NPC) migration within the subventricular zone (SVZ) of the lateral ganglionic eminence is an active process throughout early brain development. The migration of human NPCs from the SVZ to the olfactory bulb during fetal stages resembles what occurs in adult rodents. As the human brain develops during infancy, this migratory stream is drastically reduced in cell number and becomes barely evident in adults. The mechanisms regulating human NPC migration are unknown. The Slit-Robo signaling pathway has been defined as a chemorepulsive cue involved in axon guidance and neuroblast migration in rodents. Slit and Robo proteins expressed in the rodent brain help guide neuroblast migration from the SVZ through the rostral migratory stream to the olfactory bulb. Here, we present the first study on the role that Slit and Robo proteins play in human-derived fetal neural progenitor cell migration (hfNPC). We describe that Robo1 and Robo2 isoforms are expressed in the human fetal SVZ. Furthermore, we demonstrate that Slit2 is able to induce a chemorepellent effect on the migration of hfNPCs derived from the human fetal SVZ. In addition, when Robo1 expression is inhibited, hfNPCs are unable to migrate to the olfactory bulb of mice when injected in the anterior SVZ. Our findings indicate that the migration of human NPCs from the SVZ is partially regulated by the Slit-Robo axis. This pathway could be regulated to direct the migration of NPCs in human endogenous neural cell therapy. Stem Cells 2017;35:1860-1865.
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Affiliation(s)
- Hugo Guerrero-Cazares
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Fl, USA (current)
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD. USA (former)
| | - Emily Lavell
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Fl, USA (current)
| | - Linda Chen
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Paula Schiapparelli
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Fl, USA (current)
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD. USA (former)
| | | | - Vivian Capilla-Gonzalez
- Department of Stem Cells, Andalusian Molecular Biology and Regenerative Medicine Centre, Seville, Spain
| | | | | | - Liron Noiman
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Katrina Thaler
- Department of Gynecology and Obstetrics, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Anne Burke
- Department of Gynecology and Obstetrics, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Alfredo Quiñones-Hinojosa
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Fl, USA (current)
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD. USA (former)
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17
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Abstract
The early olfactory system is organized in parallel, with numerous, specialized subsystems established by the modular and topographic projections of sensory inputs. While these anatomical sub-systems are in many cases demarcated by well-known marker genes, we stand to learn considerably more about their possible functional specializations from comprehensive, genome-scale descriptions of their molecular anatomy. Here, we leverage the resources of the Allen Brain Atlas (ABA)—a spatially registered compendium of gene expression for the mouse brain—to investigate the early olfactory system’s genomic anatomy. We cluster thousands of genes across thousands of voxels in the ABA to derive several novel parcellations of the olfactory system, and concomitantly discover novel sets of enriched, subregion-specific genes that can serve as a starting point for future inquiry.
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Affiliation(s)
- Torben Noto
- Department of Cognitive Science, University of California San Diego, La Jolla, California, United States of America
| | - Derrick Barnagian
- Department of Brain and Cognitive Sciences, MIT, Cambridge, Massachusetts, United States of America
| | - Jason B. Castro
- Neuroscience Program, Bates College, Lewiston, Maine, United States of America
- * E-mail:
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18
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Ramírez-López MT, Vázquez M, Lomazzo E, Hofmann C, Blanco RN, Alén F, Antón M, Decara J, Arco R, Orio L, Suárez J, Lutz B, Gómez de Heras R, Bindila L, Rodríguez de Fonseca F. A moderate diet restriction during pregnancy alters the levels of endocannabinoids and endocannabinoid-related lipids in the hypothalamus, hippocampus and olfactory bulb of rat offspring in a sex-specific manner. PLoS One 2017; 12:e0174307. [PMID: 28346523 PMCID: PMC5367805 DOI: 10.1371/journal.pone.0174307] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 03/07/2017] [Indexed: 01/09/2023] Open
Abstract
Undernutrition during pregnancy has been associated to increased vulnerability to develop metabolic and behavior alterations later in life. The endocannabinoid system might play an important role in these processes. Therefore, we investigated the effects of a moderate maternal calorie-restricted diet on the levels of the endocannabinoid 2-arachidonoyl glycerol (2-AG), arachidonic acid (AA) and the N-acylethanolamines (NAEs) anandamide (AEA), oleoylethanolamide (OEA) and palmitoylethanolamide (PEA) in the brain of newborn rat offspring. We focused on brain structures involved in metabolism, feeding behavior, as well as emotional and cognitive responses. Female Wistar rats were assigned during the entire pregnancy to either control diet (C) or restriction diet (R), consisting of a 20% calorie-restricted diet. Weight gain and caloric intake of rat dams were monitored and birth outcomes were assessed. 2-AG, AA and NAE levels were measured in hypothalamus, hippocampus and olfactory bulb of the offspring. R dams displayed lower gain weight from the middle pregnancy and consumed less calories during the entire pregnancy. Offspring from R dams were underweight at birth, but litter size was unaffected. In hypothalamus, R male offspring displayed decreased levels of AA and OEA, with no change in the levels of the endocannabinoids 2-AG and AEA. R female exhibited decreased 2-AG and PEA levels. The opposite was found in the hippocampus, where R male displayed increased 2-AG and AA levels, and R female exhibited elevated levels of AEA, AA and PEA. In the olfactory bulb, only R female presented decreased levels of AEA, AA and PEA. Therefore, a moderate diet restriction during the entire pregnancy alters differentially the endocannabinoids and/or endocannabinoid-related lipids in hypothalamus and hippocampus of the underweight offspring, similarly in both sexes, whereas sex-specific alterations occur in the olfactory bulb. Consequently, endocannabinoid and endocannabinoid-related lipid signaling alterations might be involved in the long-term and sexual dimorphism effects commonly observed after undernutrition and low birth weight.
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Affiliation(s)
- María Teresa Ramírez-López
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
| | - Mariam Vázquez
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
- IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
| | - Ermelinda Lomazzo
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Clementine Hofmann
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Rosario Noemi Blanco
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
| | - Francisco Alén
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
| | - María Antón
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
| | - Juan Decara
- IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
| | - Rocío Arco
- IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
| | - Laura Orio
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
| | - Juan Suárez
- IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
- Departamento de Biología Celular, Genética y Fisiología. IBIMA. Facultad de Ciencias, Universidad de Malaga. Campus de Teatinos s/n, Malaga, Spain
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Raquel Gómez de Heras
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
- * E-mail: (FRF); (RGH)
| | - Laura Bindila
- Institute of Physiological Chemistry, University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany
| | - Fernando Rodríguez de Fonseca
- Departamento de Psicobiología. Facultad de Psicología, Universidad Complutense de Madrid. Campus de Somosaguas s/n, Pozuelo de Alarcón, Madrid, Spain
- IBIMA, Unidad de Gestión Clínica de Salud Mental, Hospital Regional Universitario de Málaga, Universidad de Málaga, Málaga, Spain
- * E-mail: (FRF); (RGH)
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19
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Muroyama Y, Baba A, Kitagawa M, Saito T. Olfactory Sensory Neurons Control Dendritic Complexity of Mitral Cells via Notch Signaling. PLoS Genet 2016; 12:e1006514. [PMID: 28027303 PMCID: PMC5189955 DOI: 10.1371/journal.pgen.1006514] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 11/29/2016] [Indexed: 11/29/2022] Open
Abstract
Mitral cells (MCs) of the mammalian olfactory bulb have a single primary dendrite extending into a single glomerulus, where they receive odor information from olfactory sensory neurons (OSNs). Molecular mechanisms for controlling dendritic arbors of MCs, which dynamically change during development, are largely unknown. Here we found that MCs displayed more complex dendritic morphologies in mouse mutants of Maml1, a crucial gene in Notch signaling. Similar phenotypes were observed by conditionally misexpressing a dominant negative form of MAML1 (dnMAML1) in MCs after their migration. Conversely, conditional misexpression of a constitutively active form of Notch reduced their dendritic complexity. Furthermore, the intracellular domain of Notch1 (NICD1) was localized to nuclei of MCs. These findings suggest that Notch signaling at embryonic stages is involved in the dendritic complexity of MCs. After the embryonic misexpression of dnMAML1, many MCs aberrantly extended dendrites to more than one glomerulus at postnatal stages, suggesting that Notch signaling is essential for proper formation of olfactory circuits. Moreover, dendrites in cultured MCs were shortened by Jag1-expressing cells. Finally, blocking the activity of Notch ligands in OSNs led to an increase in dendritic complexity as well as a decrease in NICD1 signals in MCs. These results demonstrate that the dendritic complexity of MCs is controlled by their presynaptic partners, OSNs. Olfactory circuits are critical for the survival of many animals. Odor information is transmitted from olfactory sensory neurons (OSNs) to relay neurons, the morphology of which is crucial for processing of the information and similar among species. The major relay neurons, mitral cells (MCs) in mammals and projection neurons in flies, have a single primary dendrite at the mature stage. Molecular mechanisms to control the formation of the dendrite are largely unknown. MCs dynamically change their dendrites during development. In this study, we show that the dendritic morphologies of MCs are controlled by Notch signaling, many factors of which are well conserved among species. Moreover, we have found that Notch signaling in MCs is activated by OSNs, and that Notch operates in the relay neurons in the mouse olfactory system, in contrast to the fly system, where Notch functions in OSNs. Therefore, our study has revealed a novel step for shaping the dendritic morphologies of MCs.
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Affiliation(s)
- Yuko Muroyama
- Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Atsushi Baba
- Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Motoo Kitagawa
- Department of Molecular and Tumor Pathology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Tetsuichiro Saito
- Department of Developmental Biology, Graduate School of Medicine, Chiba University, Chiba, Japan
- * E-mail:
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Hu R, Ferguson KA, Whiteus CB, Meijer DH, Araneda RC. Hyperpolarization-Activated Currents and Subthreshold Resonance in Granule Cells of the Olfactory Bulb. eNeuro 2016; 3:ENEURO.0197-16.2016. [PMID: 27844056 PMCID: PMC5095762 DOI: 10.1523/eneuro.0197-16.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Revised: 10/19/2016] [Accepted: 10/24/2016] [Indexed: 12/22/2022] Open
Abstract
An important contribution to neural circuit oscillatory dynamics is the ongoing activation and inactivation of hyperpolarization-activated currents (Ih). Network synchrony dynamics play an important role in the initial processing of odor signals by the main olfactory bulb (MOB) and accessory olfactory bulb (AOB). In the mouse olfactory bulb, we show that Ih is present in granule cells (GCs), the most prominent inhibitory neuron in the olfactory bulb, and that Ih underlies subthreshold resonance in GCs. In accord with the properties of Ih, the currents exhibited sensitivity to changes in extracellular K+ concentration and ZD7288 (4-ethylphenylamino-1,2-dimethyl-6-methylaminopyrimidin chloride), a blocker of Ih. ZD7288 also caused GCs to hyperpolarize and increase their input resistance, suggesting that Ih is active at rest in GCs. The inclusion of cAMP in the intracellular solution shifted the activation of Ih to less negative potentials in the MOB, but not in the AOB, suggesting that channels with different subunit composition mediate Ih in these regions. Furthermore, we show that mature GCs exhibit Ih-dependent subthreshold resonance in the theta frequency range (4-12 Hz). Another inhibitory subtype in the MOB, the periglomerular cells, exhibited Ih-dependent subthreshold resonance in the delta range (1-4 Hz), while principal neurons, the mitral cells, do not exhibit Ih-dependent subthreshold resonance. Importantly, Ih size, as well as the strength and frequency of resonance in GCs, exhibited a postnatal developmental progression, suggesting that this development of Ih in GCs may differentially contribute to their integration of sensory input and contribution to oscillatory circuit dynamics.
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Affiliation(s)
- Ruilong Hu
- Department of Biology, University of Maryland, College Park, Maryland 20742
| | - Katie A. Ferguson
- Neurobiology Course, Marine Biology Laboratory, Woods Hole, Massachusetts 02543
| | | | - Dimphna H. Meijer
- Neurobiology Course, Marine Biology Laboratory, Woods Hole, Massachusetts 02543
| | - Ricardo C. Araneda
- Department of Biology, University of Maryland, College Park, Maryland 20742
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21
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Abstract
Identifying and defining the characteristic features of the inhibitory neurons in the nervous system has become essential for achieving a cellular understanding of complex brain activities. For this, the olfactory bulb is ideally suited because it is readily accessible, it is a laminated structure where local interneurons can be easily distinguished from projecting neurons, and, more important, GABAergic interneurons are continuously replaced. How the newly generated neurons integrate into a preexisting neural network and how basic network functions are maintained when a large percentage of neurons are subjected to continuous renewal are important questions that have recently received new insights. Here, it is seen that the production of bulbar interneurons is specifically adapted to experience-dependent regulation of adult neural networks. In particular, the authors report the degree of sensitivity of the bulbar neurogenesis to the activity level of sensory inputs and, in turn, how the adult neurogenesis adjusts the neural network functioning to optimize information processing. By maintaining a constitutive neurogenesis sensitive to environmental cues, this neuronal recruitment leads to improving sensory abilities. This review brings together recently described properties and emerging principles of interneuron functions that may convey, into bulbar neuronal networks, a degree of circuit adaptation unmatched by synaptic plasticity alone.
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Affiliation(s)
- Pierre-Marie Lledo
- Laboratory of Perception and Memory, Centre National de la Recherche Scientifique, Pasteur Institute, Paris, France.
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22
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Oleszkiewicz A, Walliczek-Dworschak U, Klötze P, Gerber F, Croy I, Hummel T. Developmental Changes in Adolescents' Olfactory Performance and Significance of Olfaction. PLoS One 2016; 11:e0157560. [PMID: 27332887 PMCID: PMC4917097 DOI: 10.1371/journal.pone.0157560] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 06/01/2016] [Indexed: 11/25/2022] Open
Abstract
Aim of the current work was to examine developmental changes in adolescents' olfactory performance and personal significance of olfaction. In the first study olfactory identification abilities of 76 participants (31 males and 45 females aged between 10 and 18 years; M = 13.8, SD = 2.3) was evaluated with the Sniffin Stick identification test, presented in a cued and in an uncued manner. Verbal fluency was additionally examined for control purpose. In the second study 131 participants (46 males and 85 females aged between 10 and 18 years; (M = 14.4, SD = 2.2) filled in the importance of olfaction questionnaire. Odor identification abilities increased significantly with age and were significantly higher in girls as compared to boys. These effects were especially pronounced in the uncued task and partly related to verbal fluency. In line, the personal significance of olfaction increased with age and was generally higher among female compared to male participants.
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Affiliation(s)
- Anna Oleszkiewicz
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- Institute of Psychology, University of Wroclaw, Wroclaw, Poland
| | - Ute Walliczek-Dworschak
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- Department of Otorhinolaryngology, Philipps-University, Marburg, Germany
| | - Paula Klötze
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Friederike Gerber
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Ilona Croy
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
- Department of Psychotherapy and Psychosomatic Medicine, TU Dresden, Dresden, Germany
| | - Thomas Hummel
- Interdisciplinary Center “Smell & Taste”, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
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Brunjes PC, Osterberg SK. Developmental Markers Expressed in Neocortical Layers Are Differentially Exhibited in Olfactory Cortex. PLoS One 2015; 10:e0138541. [PMID: 26407299 PMCID: PMC4583488 DOI: 10.1371/journal.pone.0138541] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/31/2015] [Indexed: 11/28/2022] Open
Abstract
Neurons in the cerebral cortex stratify on the basis of their time of origin, axonal terminations and the molecular identities assigned during early development. Olfactory cortices share many feature with the neocortex, including clear lamination and similar cell types. The present study demonstrates that the markers differentially expressed in the projection neurons of the cerebral cortex are also found in olfactory areas. Three of the four regions examined (pars principalis of the anterior olfactory nucleus: AONpP, anterior and posterior piriform cortices: APC, PPC, and the olfactory tubercle) expressed transcription factors found in deep or superficial neurons in the developing neocortex, though large differences were found between areas. For example, while the AONpP, APC and PPC all broadly expressed the deep cortical marker CTIP2, NOR1 (NR4a3) levels were higher in AONpP and DAARP-32 was more prevalent in the APC and PPC. Similar findings were encountered for superficial cortical markers: all three regions broadly expressed CUX1, but CART was only observed in the APC and PPC. Furthermore, regional variations were observed even within single structures (e.g., NOR1 was found primarily in in the dorsal region of AONpP and CART expression was observed in a discrete band in the middle of layer 2 of both the APC and PPC). Experiments using the mitotic marker EDU verified that the olfactory cortices and neocortex share similar patterns of neuronal production: olfactory cells that express markers found in the deep neocortex are produced earlier than those that express superficial makers. Projection neurons were filled by retrograde tracers injected into the olfactory bulb to see if olfactory neurons with deep and superficial markers had different axonal targets. Unlike the cerebral cortex, no specificity was observed: neurons with each of the transcription factors examined were found to be labelled. Together the results indicate that olfactory cortices are complex: they differ from each other and each is formed from a variable mosaic of neurons. The results suggest that the olfactory cortices are not merely a remnant architype of the primordial forebrain but varied and independent regions.
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Affiliation(s)
- Peter C. Brunjes
- Department Psychology, University of Virginia, Charlottesville, Virginia, 22904, United States of America
- * E-mail:
| | - Stephen K. Osterberg
- Department Psychology, University of Virginia, Charlottesville, Virginia, 22904, United States of America
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Schreglmann SR, Regensburger M, Rockenstein E, Masliah E, Xiang W, Winkler J, Winner B. The temporal expression pattern of alpha-synuclein modulates olfactory neurogenesis in transgenic mice. PLoS One 2015; 10:e0126261. [PMID: 25961568 PMCID: PMC4427489 DOI: 10.1371/journal.pone.0126261] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/31/2015] [Indexed: 12/11/2022] Open
Abstract
Background Adult neurogenesis mirrors the brain´s endogenous capacity to generate new neurons throughout life. In the subventricular zone/ olfactory bulb system adult neurogenesis is linked to physiological olfactory function and has been shown to be impaired in murine models of neuronal alpha-Synuclein overexpression. We analyzed the degree and temporo-spatial dynamics of adult olfactory bulb neurogenesis in transgenic mice expressing human wild-type alpha-Synuclein (WTS) under the murine Thy1 (mThy1) promoter, a model known to have a particularly high tg expression associated with impaired olfaction. Results Survival of newly generated neurons (NeuN-positive) in the olfactory bulb was unchanged in mThy1 transgenic animals. Due to decreased dopaminergic differentiation a reduction in new dopaminergic neurons within the olfactory bulb glomerular layer was present. This is in contrast to our previously published data on transgenic animals that express WTS under the control of the human platelet-derived growth factor β (PDGF) promoter, that display a widespread decrease in survival of newly generated neurons in regions of adult neurogenesis, resulting in a much more pronounced neurogenesis deficit. Temporal and quantitative expression analysis using immunofluorescence co-localization analysis and Western blots revealed that in comparison to PDGF transgenic animals, in mThy1 transgenic animals WTS is expressed from later stages of neuronal maturation only but at significantly higher levels both in the olfactory bulb and cortex. Conclusions The dissociation between higher absolute expression levels of alpha-Synuclein but less severe impact on adult olfactory neurogenesis in mThy1 transgenic mice highlights the importance of temporal expression characteristics of alpha-Synuclein on the maturation of newborn neurons.
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Affiliation(s)
| | - Martin Regensburger
- IZKF Junior Research Group III and BMBF Research Group Neuroscience, Interdisciplinary Center for Clinical Research, FAU Erlangen-Nürnberg, Nikolaus-Fiebiger Center for Molecular Medicine, Erlangen, Germany
- Department of Neurology, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Edward Rockenstein
- Department of Neurosciences, University of California San Diego, La Jolla, California, CA, United States of America
- Department of Pathology, University of California San Diego, La Jolla, California, CA, United States of America
| | - Eliezer Masliah
- Department of Neurosciences, University of California San Diego, La Jolla, California, CA, United States of America
- Department of Pathology, University of California San Diego, La Jolla, California, CA, United States of America
| | - Wei Xiang
- Institute of Biochemistry, Emil-Fischer-Zentrum, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Jürgen Winkler
- Department of Molecular Neurology, FAU Erlangen-Nürnberg, Erlangen, Germany
| | - Beate Winner
- IZKF Junior Research Group III and BMBF Research Group Neuroscience, Interdisciplinary Center for Clinical Research, FAU Erlangen-Nürnberg, Nikolaus-Fiebiger Center for Molecular Medicine, Erlangen, Germany
- * E-mail:
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25
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Nazareth L, Lineburg KE, Chuah MI, Tello Velasquez J, Chehrehasa F, St John JA, Ekberg JAK. Olfactory ensheathing cells are the main phagocytic cells that remove axon debris during early development of the olfactory system. J Comp Neurol 2015; 523:479-94. [PMID: 25312022 DOI: 10.1002/cne.23694] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 10/09/2014] [Accepted: 10/10/2014] [Indexed: 11/07/2022]
Abstract
During development of the primary olfactory system, axon targeting is inaccurate and axons inappropriately project within the target layer or overproject into the deeper layers of the olfactory bulb. As a consequence there is considerable apoptosis of primary olfactory neurons during embryonic and postnatal development and axons of the degraded neurons need to be removed. Olfactory ensheathing cells (OECs) are the glia of the primary olfactory nerve and are known to phagocytose axon debris in the adult and postnatal animal. However, it is unclear when phagocytosis by OECs first commences. We investigated the onset of phagocytosis by OECs in the developing mouse olfactory system by utilizing two transgenic reporter lines: OMP-ZsGreen mice which express bright green fluorescent protein in primary olfactory neurons, and S100β-DsRed mice which express red fluorescent protein in OECs. In crosses of these mice, the fate of the degraded axon debris is easily visualized. We found evidence of axon degradation at embryonic day (E)13.5. Phagocytosis of the primary olfactory axon debris by OECs was first detected at E14.5. Phagocytosis of axon debris continued into the postnatal animal during the period when there was extensive mistargeting of olfactory axons. Macrophages were often present in close proximity to OECs but they contributed only a minor role to clearing the axon debris, even after widespread degeneration of olfactory neurons by unilateral bulbectomy and methimazole treatment. These results demonstrate that from early in embryonic development OECs are the primary phagocytic cells of the primary olfactory nerve.
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Affiliation(s)
- Lynnmaria Nazareth
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, 4000, Queensland, Australia; Eskitis Institute for Drug Discovery, Griffith University, Nathan, 4111, Queensland, Australia
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26
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Garcia I, Quast KB, Huang L, Herman AM, Selever J, Deussing JM, Justice NJ, Arenkiel BR. Local CRH signaling promotes synaptogenesis and circuit integration of adult-born neurons. Dev Cell 2014; 30:645-59. [PMID: 25199688 DOI: 10.1016/j.devcel.2014.07.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 05/02/2014] [Accepted: 06/30/2014] [Indexed: 01/09/2023]
Abstract
Neural activity either enhances or impairs de novo synaptogenesis and circuit integration of neurons, but how this activity is mechanistically relayed in the adult brain is largely unknown. Neuropeptide-expressing interneurons are widespread throughout the brain and are key candidates for conveying neural activity downstream via neuromodulatory pathways that are distinct from classical neurotransmission. With the goal of identifying signaling mechanisms that underlie neuronal circuit integration in the adult brain, we have virally traced local corticotropin-releasing hormone (CRH)-expressing inhibitory interneurons with extensive presynaptic inputs onto new neurons that are continuously integrated into the adult rodent olfactory bulb. Local CRH signaling onto adult-born neurons promotes and/or stabilizes chemical synapses in the olfactory bulb, revealing a neuromodulatory mechanism for continued circuit plasticity, synapse formation, and integration of new neurons in the adult brain.
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Affiliation(s)
- Isabella Garcia
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Medical Scientist Training Program, Baylor College of Medicine, Houston, TX 77030, USA
| | - Kathleen B Quast
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Longwen Huang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alexander M Herman
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jennifer Selever
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jan M Deussing
- Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Nicholas J Justice
- Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Benjamin R Arenkiel
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX 77030, USA.
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27
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Ragancokova D, Rocca E, Oonk AMM, Schulz H, Rohde E, Bednarsch J, Feenstra I, Pennings RJE, Wende H, Garratt AN. TSHZ1-dependent gene regulation is essential for olfactory bulb development and olfaction. J Clin Invest 2014; 124:1214-27. [PMID: 24487590 DOI: 10.1172/jci72466] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 11/14/2013] [Indexed: 02/04/2023] Open
Abstract
The olfactory bulb (OB) receives odor information from the olfactory epithelium and relays this to the olfactory cortex. Using a mouse model, we found that development and maturation of OB interneurons depends on the zinc finger homeodomain factor teashirt zinc finger family member 1 (TSHZ1). In mice lacking TSHZ1, neuroblasts exhibited a normal tangential migration to the OB; however, upon arrival to the OB, the neuroblasts were distributed aberrantly within the radial dimension, and many immature neuroblasts failed to exit the rostral migratory stream. Conditional deletion of Tshz1 in mice resulted in OB hypoplasia and severe olfactory deficits. We therefore investigated olfaction in human subjects from families with congenital aural atresia that were heterozygous for TSHZ1 loss-of-function mutations. These individuals displayed hyposmia, which is characterized by impaired odor discrimination and reduced olfactory sensitivity. Microarray analysis, in situ hybridization, and ChIP revealed that TSHZ1 bound to and regulated expression of the gene encoding prokineticin receptor 2 (PROKR2), a G protein–coupled receptor essential for OB development. Mutations in PROKR2 lead to Kallmann syndrome, characterized by anosmia and hypogonadotrophic hypogonadism. Our data indicate that TSHZ1 is a key regulator of mammalian OB development and function and controls the expression of molecules involved in human Kallmann syndrome.
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28
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Abstract
Most animals sleep more early in life than in adulthood, but the function of early sleep is not known. Using Drosophila, we found that increased sleep in young flies was associated with an elevated arousal threshold and resistance to sleep deprivation. Excess sleep results from decreased inhibition of a sleep-promoting region by a specific dopaminergic circuit. Experimental hyperactivation of this circuit in young flies results in sleep loss and lasting deficits in adult courtship behaviors. These deficits are accompanied by impaired development of a single olfactory glomerulus, VA1v, which normally displays extensive sleep-dependent growth after eclosion. Our results demonstrate that sleep promotes normal brain development that gives rise to an adult behavior critical for species propagation and suggest that rapidly growing regions of the brain are most susceptible to sleep perturbations early in life.
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Affiliation(s)
- Matthew S. Kayser
- Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Sleep and Circadian Neurobiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zhifeng Yue
- Howard Hughes Medical Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Amita Sehgal
- Howard Hughes Medical Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
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29
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Valley MT, Henderson LG, Inverso SA, Lledo PM. Adult neurogenesis produces neurons with unique GABAergic synapses in the olfactory bulb. J Neurosci 2013; 33:14660-5. [PMID: 24027267 PMCID: PMC6705166 DOI: 10.1523/jneurosci.2845-13.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/01/2013] [Accepted: 08/05/2013] [Indexed: 01/22/2023] Open
Abstract
Neuronal regeneration occurs naturally in a few restricted mammalian brain regions, but its functional significance remains debated. Here we search for unique features in the synaptic outputs made by adult-born granule cell interneurons in the mouse olfactory bulb using optogenetic targeting of specific neuronal ages. We find that adult-born interneurons are resistant to presynaptic GABA(B)-mediated depression of GABA release compared with interneurons born just after birth that exhibit strong GABA(B) neuromodulation. Correlated with this functional change, we found altered localization of the GGABA(B)R1 protein within adult-born granule cells. These results suggest that adult neurogenesis produces a population of functionally unique GABAergic synapses in the olfactory bulb.
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Affiliation(s)
- Matthew T. Valley
- Laboratory for Perception and Memory and
- National Center of Scientific Research, Coeducational Research Unit, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, F-75015 Paris, France
| | - Lansdale G. Henderson
- Laboratory for Perception and Memory and
- National Center of Scientific Research, Coeducational Research Unit, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, F-75015 Paris, France
| | - Samuel A. Inverso
- Integrative Neurobiology of Cholinergic Systems, Pasteur Institute, F-75015 Paris, France, and
- National Center of Scientific Research, Coeducational Research Unit, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, F-75015 Paris, France
| | - Pierre-Marie Lledo
- Laboratory for Perception and Memory and
- National Center of Scientific Research, Coeducational Research Unit, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 3571, F-75015 Paris, France
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30
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Sonego M, Gajendra S, Parsons M, Ma Y, Hobbs C, Zentar MP, Williams G, Machesky LM, Doherty P, Lalli G. Fascin regulates the migration of subventricular zone-derived neuroblasts in the postnatal brain. J Neurosci 2013; 33:12171-85. [PMID: 23884926 PMCID: PMC3721833 DOI: 10.1523/jneurosci.0653-13.2013] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/17/2013] [Accepted: 06/08/2013] [Indexed: 01/01/2023] Open
Abstract
After birth, stem cells in the subventricular zone (SVZ) generate neuroblasts that migrate along the rostral migratory stream (RMS) to become interneurons in the olfactory bulb (OB). This migration is a fundamental event controlling the proper integration of new neurons in a pre-existing synaptic network. Many regulators of neuroblast migration have been identified; however, still very little is known about the intracellular molecular mechanisms controlling this process. Here, we show that the actin-bundling protein fascin is highly upregulated in mouse SVZ-derived migratory neuroblasts. Fascin-1ko mice display an abnormal RMS and a smaller OB. Bromodeoxyuridine labeling experiments show that lack of fascin significantly impairs neuroblast migration, but does not appear to affect cell proliferation. Moreover, fascin depletion substantially alters the polarized morphology of rat neuroblasts. Protein kinase C (PKC)-dependent phosphorylation of fascin on Ser39 regulates its actin-bundling activity. In vivo postnatal electroporation of phosphomimetic (S39D) or nonphosphorylatable (S39A) fascin variants followed by time-lapse imaging of brain slices demonstrates that the phospho-dependent modulation of fascin activity ensures efficient neuroblast migration. Finally, fluorescence lifetime imaging microscopy studies in rat neuroblasts reveal that the interaction between fascin and PKC can be modulated by cannabinoid signaling, which controls neuroblast migration in vivo. We conclude that fascin, whose upregulation appears to mark the transition to the migratory neuroblast stage, is a crucial regulator of neuroblast motility. We propose that a tightly regulated phospho/dephospho-fascin cycle modulated by extracellular signals is required for the polarized morphology and migration in neuroblasts, thus contributing to efficient neurogenesis.
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Affiliation(s)
| | | | - Maddy Parsons
- Randall Division, King's College London, Guy's Campus, London SE1 1UL, United Kingdom, and
| | - Yafeng Ma
- Beatson Institute for Cancer Research, Glasgow University College of Medical, Veterinary and Life Sciences, Garscube Estate, Bearsden, Glasgow G61 1BD, United Kingdom
| | - Carl Hobbs
- Wolfson Centre for Age-Related Diseases, and
| | | | | | - Laura M. Machesky
- Beatson Institute for Cancer Research, Glasgow University College of Medical, Veterinary and Life Sciences, Garscube Estate, Bearsden, Glasgow G61 1BD, United Kingdom
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31
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Mansoor AK, Thomas S, Sinha JK, Alladi PA, Ravi V, Raju TR. Olfactory tract transection reveals robust tissue-level plasticity by cellular numbers and neurotrophic factor expression in olfactory bulb. Indian J Exp Biol 2012; 50:765-770. [PMID: 23305026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Nervous system lesions are characterized by the loss of neuronal numbers and types. The neurotrophic factor levels in an injured tissue reflect their potential for regeneration. This hypothesis was investigated in olfactory bulb (OB), where olfactory tract was surgically transected disrupting neuronal migration and turnover. The effects were followed with quantification of mitral cells and three neurotrophic factors mRNA levels for 6 weeks. The neuronal numbers decreased by 3rd- and 4th-week in transected OBs followed by their restoration, comparable with that of controls at 5th- and 6th-week. The endogenous levels of three neurotrophic factors - (brain derived neurotrophic factor, insulin growth factor-1 and fibroblast growth factor-2) using qPCR showed increase at 2nd-week by 136-, 8- and 2-fold respectively. Also, there was a significant increase in specific neurotrophic factors at 5th-week and 6th-weeks. The results propose a temporal link between deployment of neurotrophic factors and the plausible restorative events for mitral cell numbers in OB.
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Affiliation(s)
- Ali Khan Mansoor
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences, Hosur Road, Bangalore 560029, India
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Anil SP, Laxmi TR, Kutty BM, Raju TR. Olfactory tract transection in neonatal rats: evidence for mitral cell regeneration and restoration of functional connectivity with its targets. Indian J Exp Biol 2012; 50:755-764. [PMID: 23305025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Central Nervous System (CNS) regeneration and repair mechanism are two important aspects of functional recovery in the adult central nervous system following brain and spinal cord injury. Following olfactory tract transection in neonatal rats, functional connectivity between the olfactory bulb and the piriform cortex gets re-established by 120 days. The recovery of the dendritic morphology was associated with the synchronized oscillatory activity between olfactory bulb and piriform cortex. Mitral cells which were regenerated after the transection showed profuse branching, indicative of their undifferentiated state. However, normal dendritic morphology could be seen by 120 days after olfactory tract transection. These results thus provide a supportive evidence for the restoration of the functional connections between the olfactory bulb and the piriform cortex at 120 days.
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Affiliation(s)
- S P Anil
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences (NIMHANS), Hosur Road, PB No. 2900, Bangalore 560 029, India
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Pathania M, Torres-Reveron J, Yan L, Kimura T, Lin TV, Gordon V, Teng ZQ, Zhao X, Fulga TA, Van Vactor D, Bordey A. miR-132 enhances dendritic morphogenesis, spine density, synaptic integration, and survival of newborn olfactory bulb neurons. PLoS One 2012; 7:e38174. [PMID: 22693596 PMCID: PMC3364964 DOI: 10.1371/journal.pone.0038174] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 05/01/2012] [Indexed: 11/24/2022] Open
Abstract
An array of signals regulating the early stages of postnatal subventricular zone (SVZ) neurogenesis has been identified, but much less is known regarding the molecules controlling late stages. Here, we investigated the function of the activity-dependent and morphogenic microRNA miR-132 on the synaptic integration and survival of olfactory bulb (OB) neurons born in the neonatal SVZ. In situ hybridization revealed that miR-132 expression occurs at the onset of synaptic integration in the OB. Using in vivo electroporation we found that sequestration of miR-132 using a sponge-based strategy led to a reduced dendritic complexity and spine density while overexpression had the opposite effects. These effects were mirrored with respective changes in the frequency of GABAergic and glutamatergic synaptic inputs reflecting altered synaptic integration. In addition, timely directed overexpression of miR-132 at the onset of synaptic integration using an inducible approach led to a significant increase in the survival of newborn neurons. These data suggest that miR-132 forms the basis of a structural plasticity program seen in SVZ-OB postnatal neurogenesis. miR-132 overexpression in transplanted neurons may thus hold promise for enhancing neuronal survival and improving the outcome of transplant therapies.
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Affiliation(s)
- Manavendra Pathania
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Juan Torres-Reveron
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Lily Yan
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Tomoki Kimura
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Tiffany V. Lin
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Valerie Gordon
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Zhao-Qian Teng
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Xinyu Zhao
- Department of Neuroscience, University of New Mexico School of Medicine, Albuquerque, New Mexico, United States of America
| | - Tudor A. Fulga
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David Van Vactor
- Department of Cell Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Angélique Bordey
- Departments of Neurosurgery, and Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, United States of America
- * E-mail:
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Todrank J, Heth G, Restrepo D. Effects of in utero odorant exposure on neuroanatomical development of the olfactory bulb and odour preferences. Proc Biol Sci 2011; 278:1949-55. [PMID: 21123261 PMCID: PMC3107656 DOI: 10.1098/rspb.2010.2314] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Accepted: 11/08/2010] [Indexed: 11/12/2022] Open
Abstract
Human babies and other young mammals prefer food odours and flavours of their mother's diet during pregnancy as well as their mother's individually distinctive odour. Newborn mice also prefer the individual odours of more closely related--even unfamiliar--lactating females. If exposure to in utero odorants-which include metabolites from the mother's diet and the foetus's genetically determined individual odour-helps shape the neuroanatomical development of the olfactory bulb, this could influence the perception of such biologically important odours that are preferred after birth. We exposed gene-targeted mice during gestation and nursing to odorants that activate GFP-tagged olfactory receptors (ORs) and then measured the effects on the size of tagged glomeruli in the olfactory bulb where axons from olfactory sensory neurons (OSNs) coalesce by OR type. We found significantly larger tagged glomeruli in mice exposed to these activating odorants in amniotic fluid, and later in mother's milk, as well as significant preferences for the activating odour. Larger glomeruli comprising OSNs that respond to consistently encountered odorants should enhance detection and discrimination of these subsequently preferred odours, which in nature would facilitate selection of palatable foods and kin recognition, through similarities in individual odours of relatives.
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Affiliation(s)
- Josephine Todrank
- Department of Cell and Developmental Biology, University of Colorado Denver, 12801 East 17th Avenue, Aurora, CO 80045, USA
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Park JS, Baek WY, Kim YH, Kim JE. In vivo expression of Osterix in mature granule cells of adult mouse olfactory bulb. Biochem Biophys Res Commun 2011; 407:842-7. [PMID: 21463606 DOI: 10.1016/j.bbrc.2011.03.129] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 03/30/2011] [Indexed: 11/15/2022]
Abstract
Osterix (Osx) has been identified as an osteoblast-specific transcription factor that is required for skeletogenesis. Here, we examined the expression of Osx in non-skeletal tissues. Together with a high expression in bones, Osx was expressed in the mouse brain, and its expression gradually increased during postnatal developmental periods. Specific-expression of Osx was observed primarily in the olfactory bulb (OB), with little in the cerebral cortex and the cerebellum. Osx expression was examined in the OB of Osx heterozygous mice with a LacZ knock-in in the Osx locus, which resulted in strong X-gal staining in the OB. X-gal-positive cells were located in the mitral and granule cell layers of the adult mouse OB, which was confirmed by immunohistochemical analysis with anti-Osx antibody. Osx expression overlapped extensively with NeuN, a marker of mature neuron, indicating that the Osx-positive cells were mature interneurons of the granule cell layer in the adult mouse OB. This is the first study to examine the in vivo expression of Osx in the mouse OB, and this finding may indicate a new function of Osx as a marker for mature neuroblasts in the OB.
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Affiliation(s)
- Ji-Soo Park
- Department of Molecular Medicine, Cell and Matrix Research Institute, BK21 Medical Education Program for Human Resources, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
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Mejia-Gervacio S, Murray K, Lledo PM. NKCC1 controls GABAergic signaling and neuroblast migration in the postnatal forebrain. Neural Dev 2011; 6:4. [PMID: 21284844 PMCID: PMC3038882 DOI: 10.1186/1749-8104-6-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2010] [Accepted: 02/01/2011] [Indexed: 11/12/2022] Open
Abstract
From an early postnatal period and throughout life there is a continuous production of olfactory bulb (OB) interneurons originating from neuronal precursors in the subventricular zone. To reach the OB circuits, immature neuroblasts migrate along the rostral migratory stream (RMS). In the present study, we employed cultured postnatal mouse forebrain slices and used lentiviral vectors to label neuronal precursors with GFP and to manipulate the expression levels of the Na-K-2Cl cotransporter NKCC1. We investigated the role of this Cl- transporter in different stages of postnatal neurogenesis, including neuroblast migration and integration in the OB networks once they have reached the granule cell layer (GCL). We report that NKCC1 activity is necessary for maintaining normal migratory speed. Both pharmacological and genetic manipulations revealed that NKCC1 maintains high [Cl-]i and regulates the resting membrane potential of migratory neuroblasts whilst its functional expression is strongly reduced at the time cells reach the GCL. As in other developing systems, NKCC1 shapes GABAA-dependent signaling in the RMS neuroblasts. Also, we show that NKCC1 controls the migration of neuroblasts in the RMS. The present study indeed indicates that the latter effect results from a novel action of NKCC1 on the resting membrane potential, which is independent of GABAA-dependent signaling. All in all, our findings show that early stages of the postnatal recruitment of OB interneurons rely on precise, orchestrated mechanisms that depend on multiple actions of NKCC1.
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Affiliation(s)
- Sheyla Mejia-Gervacio
- Institut Pasteur, Laboratory for Perception and Memory, 25 rue du Dr. Roux, F-75724 Paris Cedex 15, France
- Centre National de la Recherche Scientifique (CNRS) Unité de Recherche Associée (URA) 2182, 75724 Paris, France
| | - Kerren Murray
- Institut Pasteur, Laboratory for Perception and Memory, 25 rue du Dr. Roux, F-75724 Paris Cedex 15, France
- Centre National de la Recherche Scientifique (CNRS) Unité de Recherche Associée (URA) 2182, 75724 Paris, France
| | - Pierre-Marie Lledo
- Institut Pasteur, Laboratory for Perception and Memory, 25 rue du Dr. Roux, F-75724 Paris Cedex 15, France
- Centre National de la Recherche Scientifique (CNRS) Unité de Recherche Associée (URA) 2182, 75724 Paris, France
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Abstract
Odor signals received by odorant receptors (ORs) in the olfactory epithelium are represented as an odor map of activated glomeruli in the olfactory bulb. In the mouse olfactory system, it appears that much of axon pathfinding and sorting occurs autonomously by olfactory neuron axons. Here, we review the recent progress on the study of olfactory map formation in rodents. We will discuss how neuronal identity is represented at axon termini and how the OR-instructed axonal projection is regulated.
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Affiliation(s)
- Hitoshi Sakano
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0032, Japan.
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Zhou YY, Shao R, Liang CC, Wang Y, Wang LW. Histological studies on the telencephalon of Hynobius leechii at the metamorphosis phase and the adult phase. Neurosci Bull 2010; 25:196-202. [PMID: 19633701 DOI: 10.1007/s12264-009-0213-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To investigate the telencephalon developmental characteristics of Hynobius leehii, and enrich the research data of comparable neurobiology and nervous system development of amphibian. METHODS HE staining and Nissl staining methods were used to study the telencephalon histological structure of Hynobius leechii at both the metamorphosis and the adult phases, and to explore the developmental phases of telencephalon. RESULTS The olfactory bulb could be roughly divided into 6 layers from lateral to medial. The lateral cerebral ventricles at the metamorphosis phase were smaller than those at the adult phase, and there were no clear borderlines between the primordial pallium and the primordial hippocampus, or between the primordial pallium and the primordial piriform area. Moreover, the cells in the primordial piriform area were more closely distributed than those in the primordial hippocampus or the primordial pallium. Compared with those at the adult phase, cells in nucleuses at the metamorphosis phase were larger in number and more closely distributed. CONCLUSION The telencephalon of Hynobius leehii at the metamorphosis phase has generally formed the adult structure. However, it is still at a transition state of differentiation to maturity during the development of Hynobius leehii.
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Affiliation(s)
- Ying-Ying Zhou
- College of Chemistry and Life Science, Shenyang Normal University, Shenyang 110034, China
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Abraham E, Palevitch O, Gothilf Y, Zohar Y. Targeted gonadotropin-releasing hormone-3 neuron ablation in zebrafish: effects on neurogenesis, neuronal migration, and reproduction. Endocrinology 2010; 151:332-40. [PMID: 19861502 DOI: 10.1210/en.2009-0548] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hypophysiotropic GnRH neurons are located in the preoptic area and ventral hypothalamus of sexually mature vertebrates. In several species, the embryonic origin of hypophysiotropic GnRH neurons remains unclear. Using the Tg(GnRH3:EGFP) zebrafish line, in which GnRH3 neurons express EGFP, GnRH3 neurons in the olfactory region were specifically and individually ablated during early development using laser pulses. After ablation, the olfactory region maintained the capacity to regenerate GnRH3 neurons. However, this capacity was time-limited. When ablation of GnRH3 cells was conducted at 2 d after fertilization, high regeneration rates were observed, but regeneration capacity significantly decreased when ablation was performed at 4 or 6 d after fertilization. Unilateral GnRH3 neuron ablation results in unilateral soma presence. These unilateral somata are capable of projecting fiber extensions bilaterally. Successful bilateral GnRH3 soma ablation during development resulted in complete lack of olfactory, terminal nerve, preoptic area, and hypothalamic GnRH3 neurons and fibers in 12-wk-old animals. Mature animals lacking GnRH3 neurons exhibited arrested oocyte development and reduced average oocyte diameter. Animals in which GnRH3 neurons were partially ablated exhibited normal oocyte development; however, their fecundity was significantly reduced. These findings demonstrate that the hypophysiotropic GnRH3 populations in zebrafish consist of neurons that originate in the olfactory region during early development. The presence of GnRH3 neurons of olfactory region origin in reproductively mature zebrafish is a prerequisite for normal oocyte development and reproduction.
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Affiliation(s)
- Eytan Abraham
- Center of Marine Biotechnology, University of Maryland Biotechnology Institute, Baltimore, Maryland 21202, USA
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Li J, Yuan TF. Increased olfactory bulb volume due to treatment of chronic rhinosinusitis: neuroinflammation and adult neurogenesis. Brain 2009; 133:e138; author reply e139. [PMID: 20007217 DOI: 10.1093/brain/awp310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Prince JEA, Cho JH, Dumontier E, Andrews W, Cutforth T, Tessier-Lavigne M, Parnavelas J, Cloutier JF. Robo-2 controls the segregation of a portion of basal vomeronasal sensory neuron axons to the posterior region of the accessory olfactory bulb. J Neurosci 2009; 29:14211-22. [PMID: 19906969 PMCID: PMC2821732 DOI: 10.1523/jneurosci.3948-09.2009] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2009] [Revised: 09/23/2009] [Accepted: 09/25/2009] [Indexed: 11/21/2022] Open
Abstract
The ability of sensory systems to detect and process information from the environment relies on the elaboration of precise connections between sensory neurons in the periphery and second order neurons in the CNS. In mice, the accessory olfactory system is thought to regulate a wide variety of social and sexual behaviors. The expression of the Slit receptors Robo-1 and Robo-2 in vomeronasal sensory neurons (VSNs) suggests they may direct the stereotypic targeting of their axons to the accessory olfactory bulb (AOB). Here, we have examined the roles of Robo-1 and Robo-2 in the formation of connections by VSN axons within the AOB. While Robo-1 is not necessary for the segregation of VSN axons within the anterior and posterior regions of the AOB, Robo-2 is required for the targeting of some basal VSN axons to the posterior region of the AOB but is dispensable for the fasciculation of VSN axons. Furthermore, the specific ablation of Robo-2 expression in VSNs leads to mistargeting of a portion of basal VSN axons to the anterior region of the AOB, indicating that Robo-2 expression is required on projecting VSN axons. Together, these results identify Robo-2 as a receptor that controls the targeting of basal VSN axons to the posterior AOB.
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Affiliation(s)
- Janet E. A. Prince
- Montreal Neurological Institute, Centre for Neuronal Survival, Montréal, Québec H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3A 2B4, Canada
| | - Jin Hyung Cho
- Montreal Neurological Institute, Centre for Neuronal Survival, Montréal, Québec H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3A 2B4, Canada
| | - Emilie Dumontier
- Montreal Neurological Institute, Centre for Neuronal Survival, Montréal, Québec H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3A 2B4, Canada
| | - William Andrews
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Tyler Cutforth
- Department of Molecular, Cell & Developmental Biology, University of California, Santa Cruz, Santa Cruz, California 95064, and
| | | | - John Parnavelas
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Jean-François Cloutier
- Montreal Neurological Institute, Centre for Neuronal Survival, Montréal, Québec H3A 2B4, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, Québec H3A 2B4, Canada
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Abstract
Spontaneous and patterned activity, largely attributed to chemical transmission, shape the development of virtually all neural circuits. However, electrical transmission also has an important role in coordinated activity in the brain. In the olfactory bulb, gap junctions between apical dendrites of mitral cells increase excitability and synchronize firing within each glomerulus. We report here that the development of the glomerular microcircuit requires both sensory experience and connexin (Cx)36-mediated gap junctions. Coupling coefficients, which measure electrical coupling between mitral cell dendrites, were high in young mice, but decreased after postnatal day (P)10 because of a maturational increase in membrane conductance. Sensory deprivation, induced by unilateral naris occlusion at birth, slowed the morphological development of mitral cells and arrested the maturational changes in membrane conductance and coupling coefficients. As the coupling coefficients decreased in normal mice, a glutamate-mediated excitatory postsynaptic current (EPSC) between mitral cells emerged by P30. Although mitral-mitral EPSCs were generally unidirectional, they were not present in young adult Cx36(-/-) mice, suggesting that gap junctions are required for the development and/or function of the mature circuit. The experience-dependent transition from electrical transmission to combined chemical and electrical transmission provides a previously unappreciated mechanism that may tune the response properties of the glomerular microcircuit.
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Affiliation(s)
- Brady J. Maher
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
| | | | - Gary L. Westbrook
- Vollum Institute, Oregon Health and Science University, Portland, OR 97239
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Affiliation(s)
- Richard M Costanzo
- Department of Physiology, Virginia Commonwealth University, Richmond, VA 23298-0551, USA.
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Bailey MM, Boohaker JG, Jernigan PL, Townsend MB, Sturdivant J, Rasco JF, Vincent JB, Hood RD. Effects of pre- and postnatal exposure to chromium picolinate or picolinic acid on neurological development in CD-1 mice. Biol Trace Elem Res 2008; 124:70-82. [PMID: 18408898 DOI: 10.1007/s12011-008-8124-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 03/17/2008] [Indexed: 10/22/2022]
Abstract
Chromium picolinate, Cr(pic)3, a popular dietary supplement marketed as an aid in fat loss and lean muscle gain, has also been suggested as a therapy for women with gestational diabetes. The current study investigated the effects of maternal exposure to Cr(pic)3 and picolinic acid during gestation and lactation on neurological development of the offspring. Mated female CD-1 mice were fed diets from implantation through weaning that were either untreated or that contained Cr(pic)3 (200 mg kg(-1) day(-1)) or picolinic acid (174 mg kg(-1) day(-1)). A comprehensive battery of postnatal tests was administered, including a modified Fox battery, straight-channel swim, open-field activity, and odor-discrimination tests. Pups exposed to picolinic acid tended to weigh less than either control or Cr(pic)3-exposed pups, although the differences were not significant. Offspring of picolinic acid-treated dams also appeared to display impaired learning ability, diminished olfactory orientation ability, and decreased forelimb grip strength, although the differences among the treatment groups were not significant. The results indicate that there were no significant effects on the offspring with regard to neurological development from supplementation of the dams with either Cr(pic)3 or picolinic acid.
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Affiliation(s)
- Melissa M Bailey
- Department of Biological Sciences, The University of Alabama, Box 870344, Tuscaloosa, AL 35487-0344, USA
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Kelsch W, Mosley CP, Lin CW, Lois C. Distinct mammalian precursors are committed to generate neurons with defined dendritic projection patterns. PLoS Biol 2007; 5:e300. [PMID: 18001150 PMCID: PMC2071944 DOI: 10.1371/journal.pbio.0050300] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Accepted: 09/19/2007] [Indexed: 11/19/2022] Open
Abstract
The mechanisms that regulate how dendrites target different neurons to establish connections with specific cell types remain largely unknown. In particular, the formation of cell-type-specific connectivity during postnatal neurogenesis could be either determined by the local environment of the mature neuronal circuit or by cell-autonomous properties of the immature neurons, already determined by their precursors. Using retroviral fate mapping, we studied the lamina-specific dendritic targeting of one neuronal type as defined by its morphology and intrinsic somatic electrical properties in neonatal and adult neurogenesis. Fate mapping revealed the existence of two separate populations of neuronal precursors that gave rise to the same neuronal type with two distinct patterns of dendritic targeting-innervating either a deep or superficial lamina, where they connect to different types of principal neurons. Furthermore, heterochronic and heterotopic transplantation demonstrated that these precursors were largely restricted to generate neurons with a predetermined pattern of dendritic targeting that was independent of the host environment. Our results demonstrate that, at least in the neonatal and adult mammalian brain, the pattern of dendritic targeting of a given neuron is a cell-autonomous property of their precursors.
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Affiliation(s)
- Wolfgang Kelsch
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Colleen P Mosley
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Chia-Wei Lin
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Carlos Lois
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
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Abstract
During embryonic development, olfactory sensory neurons extend axons that form synapses with the dendrites of projection neurons in glomeruli of the olfactory bulb (OB). The glycosyltransferase beta3GnT1 regulates the expression of 1B2-reactive lactosamine glycans that are mosaically distributed among glomeruli. In newborn beta3GnT1-/- mice, lactosamine expression is lost, and many glomeruli fail to form. To determine the role of lactosamine in OB targeting, we analyzed the trajectories of specific OR axon populations and their reactivity with 1B2 in beta3GnT1-/- mice. mI7 axons and P2 axons, both of which are weakly 1B2+ in wild-type mice, fail to grow to their normal positions in the glomerular layer during early postnatal development and never recover in adult mutant mice. In contrast, many M72 axons, which are always lactosamine negative in wild-type mice, survive but are misguided to the extreme anterior OB in neonatal mutant mice and persist as heterotypic glomeruli, even in adult null mice. These results show that the loss of lactosamine differentially affects each OR population. Those that lose their normal expression of lactosamine fail to form stable connections with mitral and tufted cells in the OB, disappear during early postnatal development, and do not recover in adults. Neurons that are normally lactosamine negative, survive early postnatal degeneration in beta3GnT1-/- mice but extend axons that converge on inappropriate targets in the mutant OB.
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Abstract
In mammals, olfactory bulb (OB) interneurons, granule cells and periglomerular (PG) cells, are generated throughout adulthood. PG cells comprise a heterogeneous population in both morphology and molecular phenotypes. It is unknown whether adult genesis of PG cells occurs among all subtypes or is limited to a subpopulation. We show that within 2 weeks after retroviral labeling in the subventricular zone, two morphological populations of PG cells are found in the OB, one with large multi-glomerular dendritic arbors, and one with dendritic arbors limited to one or two glomeruli. On both types, immature dendritic spines are first evident at 4 weeks and mature, pedunculated spines by 6 weeks. To differentiate PG subpopulations we used expression of calcium binding proteins, GAD67 and tyrosine hydroxylase as markers. Among adult-born BrdU labeled cells, all molecular subtypes were represented, although GAD67 and tyrosine hydroxylase expressing cells were overrepresented proportional to their expression in the total PG cell population. During the time when spines are maturing, approximately half the PG cells are lost, in roughly equal proportions to their generation. Our data show the diverse developmental potential of SVZ neuroblasts and suggest that integration into synaptic circuits is necessary for survival.
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Affiliation(s)
- Mary C Whitman
- Department of Neurobiology, Yale University School of Medicine, New Haven, Connecticut 06520-8082, USA
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So K, Moriya T, Nishitani S, Takahashi H, Shinohara K. The olfactory conditioning in the early postnatal period stimulated neural stem/progenitor cells in the subventricular zone and increased neurogenesis in the olfactory bulb of rats. Neuroscience 2007; 151:120-8. [PMID: 18093744 DOI: 10.1016/j.neuroscience.2007.07.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Revised: 07/03/2007] [Accepted: 07/26/2007] [Indexed: 11/18/2022]
Abstract
The olfactory memory acquired during the early postnatal period is known to be maintained for a long period, however, its neural mechanism remains to be clarified. In the present study, we examined the effect of olfactory conditioning during the early postnatal period on neurogenesis in the olfactory bulb of rats. Using the bromodeoxyuridine-pulse chase method, we found that the olfactory conditioning, which was a paired presentation of citral odor (conditioned stimulus) and foot shock (unconditioned stimulus) in rat pups on postnatal day 11, stimulated the proliferation of neural stem/progenitor cells in the anterior subventricular zone (aSVZ), but not in the olfactory bulb, at 24 h after the conditioning. However, the number of newborn cells in the olfactory bulb was increased at 2 weeks, but not 8 weeks, after such conditioning. Neither the exposure of a citral odor alone nor foot shock alone affected the proliferation of neural stem/progenitor cells in the aSVZ at 24 h after and the number of newborn cells in the olfactory bulb at 2 weeks after. The majority of newborn cells in the olfactory bulb of either the conditioned rats or the unconditioned rats expressed the neural marker NeuN, thus indicating that the olfactory conditioning stimulated neurogenesis in the olfactory bulb. These results suggest that olfactory conditioning during the early postnatal period temporally stimulates neurogenesis in the olfactory bulb of rats.
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Affiliation(s)
- K So
- Department of Neurobiology and Behavior, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8523, Japan
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Chehrehasa F, Key B, St John JA. The shape of the olfactory bulb influences axon targeting. Brain Res 2007; 1169:17-23. [PMID: 17698047 DOI: 10.1016/j.brainres.2007.06.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2006] [Revised: 06/26/2007] [Accepted: 06/26/2007] [Indexed: 11/17/2022]
Abstract
Each primary olfactory neuron in the mouse expresses a single type of odorant receptor. All neurons expressing the same odorant receptor gene typically project to two topographically fixed glomeruli, one each on the medial and lateral surfaces of the olfactory bulb. While topographic gradients of guidance receptors and their ligands help to establish the retinotectal projection, similar orthogonal distributions of cues have not yet been detected within the olfactory system. While odorant receptors are crucial for the final targeting of axons to glomeruli, it is unclear whether the olfactory bulb itself provides instructive cues for the establishment of the topographic map. To begin to understand the role of the olfactory bulb in the formation of the olfactory nerve pathway, we developed a model whereby the gross shape of the bulb in the P2-IRES-tau-LacZ line of mice was radically altered during postnatal development. We have shown here that the topography of axons expressing the P2 odorant receptor is dependent on the shape of the olfactory bulb. When the dorsoventral axis of the olfactory bulb was compressed during the early postnatal period, newly developing P2 axons projected to multiple inappropriate glomeruli surrounding their normal target site. These results suggest that the distribution of local guidance cues within the olfactory bulb is influenced by the shape of the olfactory bulb and that these cues contribute to the topographic positioning of glomeruli.
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Affiliation(s)
- Fatemeh Chehrehasa
- Brain Growth and Regeneration Lab, Discipline of Anatomy and Developmental Biology, School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia
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Young KM, Merson TD, Sotthibundhu A, Coulson EJ, Bartlett PF. p75 neurotrophin receptor expression defines a population of BDNF-responsive neurogenic precursor cells. J Neurosci 2007; 27:5146-55. [PMID: 17494700 PMCID: PMC6672366 DOI: 10.1523/jneurosci.0654-07.2007] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Although our understanding of adult neurogenesis has increased dramatically over the last decade, confusion still exists regarding both the identity of the stem cell responsible for neuron production and the mechanisms that regulate its activity. Here we show, using flow cytometry, that a small population of cells (0.3%) within the stem cell niche of the rat subventricular zone (SVZ) expresses the p75 neurotrophin receptor (p75(NTR)) and that these cells are responsible for neuron production in both newborn and adult animals. In the adult, the p75(NTR)-positive population contains all of the neurosphere-producing precursor cells, whereas in the newborn many of the precursor cells are p75(NTR) negative. However, at both ages, only the neurospheres derived from p75(NTR)-positive cells are neurogenic. We also show that neuron production from p75(NTR)-positive but not p75(NTR)-negative precursors is greatly enhanced after treatment with brain-derived neurotrophic factor (BDNF) or nerve growth factor. This effect appears to be mediated specifically by p75(NTR), because precursor cells from p75(NTR)-deficient mice show a 70% reduction in their neurogenic potential in vitro and fail to respond to BDNF treatment. Furthermore, adult p75(NTR)-deficient mice have significantly reduced numbers of PSA-NCAM (polysialylated neural cell adhesion molecule)-positive SVZ neuroblasts in vivo and a lower olfactory bulb weight. Thus, p75(NTR) defines a discrete population of highly proliferative SVZ precursor cells that are able to respond to neurotrophin activation by increasing neuroblast generation, making this pathway the most likely mechanism for the increased neurogenesis that accompanies raised BDNF levels in a variety of disease and behavioral situations.
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Affiliation(s)
- Kaylene M. Young
- Queensland Brain Institute, The University of Queensland, Brisbane QLD 4072, Australia
- The Walter and Eliza Hall Institute for Medical Research, Melbourne VIC 3050, Australia, and
| | - Tobias D. Merson
- Howard Florey Institute, The University of Melbourne, Melbourne VIC 3010, Australia
| | - Areechun Sotthibundhu
- Queensland Brain Institute, The University of Queensland, Brisbane QLD 4072, Australia
| | - Elizabeth J. Coulson
- Queensland Brain Institute, The University of Queensland, Brisbane QLD 4072, Australia
| | - Perry F. Bartlett
- Queensland Brain Institute, The University of Queensland, Brisbane QLD 4072, Australia
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