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Perez GA, Park KW, Lanza D, Cicardo J, Danish Uddin M, Jankowsky JL. Generation of a Dcx-CreER T2 knock-in mouse for genetic manipulation of newborn neurons. Genesis 2024; 62:e23584. [PMID: 38102875 PMCID: PMC11021165 DOI: 10.1002/dvg.23584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 11/19/2023] [Accepted: 11/29/2023] [Indexed: 12/17/2023]
Abstract
A wide variety of CreERT2 driver lines are available for genetic manipulation of adult-born neurons in the mouse brain. These tools have been instrumental in studying fate potential, migration, circuit integration, and morphology of the stem cells supporting lifelong neurogenesis. Despite a wealth of tools, genetic manipulation of adult-born neurons for circuit and behavioral studies has been limited by poor specificity of many driver lines targeting early progenitor cells and by the inaccessibility of lines selective for later stages of neuronal maturation. We sought to address these limitations by creating a new CreERT2 driver line targeted to the endogenous mouse doublecortin locus as a marker of fate-specified neuroblasts and immature neurons. Our new model places a T2A-CreERT2 cassette immediately downstream of the Dcx coding sequence on the X chromosome, allowing expression of both Dcx and CreERT2 proteins in the endogenous spatiotemporal pattern for this gene. We demonstrate that the new mouse line drives expression of a Cre-dependent reporter throughout the brain in neonatal mice and in known neurogenic niches of adult animals. The line has been deposited with the Jackson Laboratory and should provide an accessible tool for studies targeting fate-restricted neuronal precursors.
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Affiliation(s)
- Gabriella A. Perez
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - Kyung-Won Park
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - Denise Lanza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030
| | - Jenna Cicardo
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - M. Danish Uddin
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
| | - Joanna L. Jankowsky
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Departments of Neurology, Neurosurgery, and Molecular and Cellular Biology, Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030
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Benedetti B, Reisinger M, Hochwartner M, Gabriele G, Jakubecova D, Benedetti A, Bonfanti L, Couillard‐Despres S. The awakening of dormant neuronal precursors in the adult and aged brain. Aging Cell 2023; 22:e13974. [PMID: 37649323 PMCID: PMC10726842 DOI: 10.1111/acel.13974] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023] Open
Abstract
Beyond the canonical neurogenic niches, there are dormant neuronal precursors in several regions of the adult mammalian brain. Dormant precursors maintain persisting post-mitotic immaturity from birth to adulthood, followed by staggered awakening, in a process that is still largely unresolved. Strikingly, due to the slow rate of awakening, some precursors remain immature until old age, which led us to question whether their awakening and maturation are affected by aging. To this end, we studied the maturation of dormant precursors in transgenic mice (DCX-CreERT2 /flox-EGFP) in which immature precursors were labelled permanently in vivo at different ages. We found that dormant precursors are capable of awakening at young age, becoming adult-matured neurons (AM), as well as of awakening at old age, becoming late AM. Thus, protracted immaturity does not prevent late awakening and maturation. However, late AM diverged morphologically and functionally from AM. Moreover, AM were functionally most similar to neonatal-matured neurons (NM). Conversely, late AM were endowed with high intrinsic excitability and high input resistance, and received a smaller amount of spontaneous synaptic input, implying their relative immaturity. Thus, late AM awakening still occurs at advanced age, but the maturation process is slow.
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Affiliation(s)
- Bruno Benedetti
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Maximilian Reisinger
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Marie Hochwartner
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Gabriele Gabriele
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Dominika Jakubecova
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Ariane Benedetti
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO)OrbassanoItaly
- Department of Veterinary SciencesUniversity of TurinTorinoItaly
| | - Sebastien Couillard‐Despres
- Institute of Experimental Neuroregeneration, Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI‐TReCS)Paracelsus Medical UniversitySalzburgAustria
- Austrian Cluster for Tissue RegenerationViennaAustria
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3
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Ghibaudi M, Marchetti N, Vergnano E, La Rosa C, Benedetti B, Couillard-Despres S, Farioli-Vecchioli S, Bonfanti L. Age-related changes in layer II immature neurons of the murine piriform cortex. Front Cell Neurosci 2023; 17:1205173. [PMID: 37576566 PMCID: PMC10416627 DOI: 10.3389/fncel.2023.1205173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 07/14/2023] [Indexed: 08/15/2023] Open
Abstract
The recent identification of a population of non-newly born, prenatally generated "immature" neurons in the layer II of the piriform cortex (cortical immature neurons, cINs), raises questions concerning their maintenance or depletion through the lifespan. Most forms of brain structural plasticity progressively decline with age, a feature that is particularly prominent in adult neurogenesis, due to stem cell depletion. By contrast, the entire population of the cINs is produced during embryogenesis. Then these cells simply retain immaturity in postnatal and adult stages, until they "awake" to complete their maturation and ultimately integrate into neural circuits. Hence, the question remains open whether the cINs, which are not dependent on stem cell division, might follow a similar pattern of age-related reduction, or in alternative, might leave a reservoir of young, undifferentiated cells in the adult and aging brain. Here, the number and features of cINs were analyzed in the mouse piriform cortex from postnatal to advanced ages, by using immunocytochemistry for the cytoskeletal marker doublecortin. The abundance and stage of maturation of cINs, along with the expression of other markers of maturity/immaturity were investigated. Despite a marked decrease in this neuronal population during juvenile stages, reminiscent of that observed in hippocampal neurogenesis, a small amount of highly immature cINs persisted up to advanced ages. Overall, albeit reducing in number with increasing age, we report that the cINs are present through the entire animal lifespan.
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Affiliation(s)
- Marco Ghibaudi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, Turin, Italy
| | - Nicole Marchetti
- Institute of Biochemistry and Cell Biology, National Research Council, Rome, Italy
| | - Elena Vergnano
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
| | - Chiara La Rosa
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
| | - Bruno Benedetti
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | | | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, Turin, Italy
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Benedetti B, Couillard-Despres S. Why Would the Brain Need Dormant Neuronal Precursors? Front Neurosci 2022; 16:877167. [PMID: 35464307 PMCID: PMC9026174 DOI: 10.3389/fnins.2022.877167] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/11/2022] [Indexed: 12/13/2022] Open
Abstract
Dormant non-proliferative neuronal precursors (dormant precursors) are a unique type of undifferentiated neuron, found in the adult brain of several mammalian species, including humans. Dormant precursors are fundamentally different from canonical neurogenic-niche progenitors as they are generated exquisitely during the embryonic development and maintain a state of protracted postmitotic immaturity lasting up to several decades after birth. Thus, dormant precursors are not pluripotent progenitors, but to all effects extremely immature neurons. Recently, transgenic models allowed to reveal that with age virtually all dormant precursors progressively awaken, abandon the immature state, and become fully functional neurons. Despite the limited common awareness about these cells, the deep implications of recent discoveries will likely lead to revisit our understanding of the adult brain. Thus, it is timely to revisit and critically assess the essential evidences that help pondering on the possible role(s) of these cells in relation to cognition, aging, and pathology. By highlighting pivoting findings as well as controversies and open questions, we offer an exciting perspective over the field of research that studies these mysterious cells and suggest the next steps toward the answer of a crucial question: why does the brain need dormant neuronal precursors?
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Affiliation(s)
- Bruno Benedetti
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
- Austrian Cluster for Tissue Regeneration, Vienna, Austria
- *Correspondence: Sebastien Couillard-Despres,
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Deciphering heterogeneous populations of migrating cells based on the computational assessment of their dynamic properties. Stem Cell Reports 2022; 17:911-923. [PMID: 35303437 PMCID: PMC9023771 DOI: 10.1016/j.stemcr.2022.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 11/23/2022] Open
Abstract
Neuronal migration is a highly dynamic process, and multiple cell movement metrics can be extracted from time-lapse imaging datasets. However, these parameters alone are often insufficient to evaluate the heterogeneity of neuroblast populations. We developed an analytical pipeline based on reducing the dimensions of the dataset by principal component analysis (PCA) and determining sub-populations using k-means, supported by the elbow criterion method and validated by a decision tree algorithm. We showed that neuroblasts derived from the same adult neural stem cell (NSC) lineage as well as across different lineages are heterogeneous and can be sub-divided into different clusters based on their dynamic properties. Interestingly, we also observed overlapping clusters for neuroblasts derived from different NSC lineages. We further showed that genetic perturbations or environmental stimuli affect the migratory properties of neuroblasts in a sub-cluster-specific manner. Our data thus provide a framework for assessing the heterogeneity of migrating neuroblasts. Pipeline to study the heterogeneity of migrating cells based on their dynamic properties Neuroblasts derived from the same neural stem cell (NSC) lineage are heterogeneous Neuroblasts derived from different NSC lineages have overlapping and distinct clusters These clusters are differently affected by genetic factors or environmental stimuli
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6
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Chen J, Guan Z. Function of Oncogene Mycn in Adult Neurogenesis and Oligodendrogenesis. Mol Neurobiol 2021; 59:77-92. [PMID: 34625907 PMCID: PMC8786763 DOI: 10.1007/s12035-021-02584-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022]
Abstract
Human MYCN is an oncogene amplified in neuroblastoma and many other tumors. Both human MYCN and mouse Mycn genes are important in embryonic brain development, but their functions in adult healthy nerve system are completely unknown. Here, with Mycn-eGFP mice and quantitative RT-PCR, we found that Mycn was expressed in specific brain regions of young adult mice, including subventricular zone (SVZ), subgranular zone (SGZ), olfactory bulb (OB), subcallosal zone (SCZ), and corpus callosum (CC). With immunohistochemistry (IHC), we found that many Mycn-expressing cells expressed neuroblast marker doublecortin (DCX) and proliferation marker Ki67. With Dcx-creER and Mki67-creER mouse lines, we fate mapped Dcx-expressing neuroblasts and Mki67-expressing proliferation cells, along with deleting Mycn from these cells in adult mice. We found that knocking out Mycn from adult neuroblasts or proliferating cells significantly reduced cells in proliferation in SVZ, SGZ, OB, SCZ, and CC. We also demonstrated that the Mycn-deficient neuroblasts in SGZ matured quicker than wild-type neuroblasts, and that Mycn-deficient proliferating cells were more likely to survive in SVZ, SGZ, OB, SCZ, and CC compared to wild type. Thus, our results demonstrate that, in addition to causing tumors in the nervous system, oncogene Mycn has a crucial function in neurogenesis and oligodendrogenesis in adult healthy brain.
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Affiliation(s)
- Jiao Chen
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Zhonghui Guan
- Department of Anesthesia and Perioperative Care, University of California San Francisco, San Francisco, CA, 94143, USA.
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7
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Moura DMS, de Sales IRP, Brandão JA, Costa MR, Queiroz CM. Disentangling chemical and electrical effects of status epilepticus-induced dentate gyrus abnormalities. Epilepsy Behav 2021; 121:106575. [PMID: 31704249 DOI: 10.1016/j.yebeh.2019.106575] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/10/2019] [Accepted: 09/14/2019] [Indexed: 01/06/2023]
Abstract
In rodents, status epilepticus (SE) triggered by chemoconvulsants can differently affect the proliferation and fate of adult-born dentate granule cells (DGCs). It is unknown whether abnormal neurogenesis results from intracellular signaling associated with drug-receptor interaction, paroxysmal activity, or both. To test the contribution of these factors, we systematically compared the effects of kainic acid (KA)- and pilocarpine (PL)-induced SE on the morphology and localization of DGCs generated before or after SE in the ipsi- and contralateral hippocampi of mice. Hippocampal insult was induced by unilateral intrahippocampal (ihpc) administration of KA or PL. We employed conditional doublecortin-dependent expression of the green fluorescent protein (GFP) to label adult-born cells committed to neuronal lineage either one month before (mature DGCs) or seven days after (immature DGCs) SE. Unilateral ihpc administration of KA and PL led to bilateral epileptiform discharges and focal and generalized behavioral seizures. However, drastic granule cell layer (GCL) dispersion occurred only in the ipsilateral side of KA injection, but not in PL-treated animals. Granule cell layer dispersion was accompanied by a significant reduction in neurogenesis after SE in the ipsilateral side of KA-treated animals, while neurogenesis increased in the contralateral side of KA-treated animals and both hippocampi of PL-treated animals. The ratio of ectopic neurons in the ipsilateral hippocampus was higher among immature as compared to mature neurons in the KA model (32.8% vs. 10.0%, respectively), while the occurrence of ectopic neurons in PL-treated animals was lower than 3% among both mature and immature DGCs. Collectively, our results suggest that KA- and PL-induced SE leads to distinct cellular alterations in mature and immature DGCs. We also show different local and secondary effects of KA or PL in the histological organization of the adult DG, suggesting that these unique epilepsy models may be complementary to our understanding of the disease. NEWroscience 2018.
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8
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Benedetti B, Dannehl D, König R, Coviello S, Kreutzer C, Zaunmair P, Jakubecova D, Weiger TM, Aigner L, Nacher J, Engelhardt M, Couillard-Després S. Functional Integration of Neuronal Precursors in the Adult Murine Piriform Cortex. Cereb Cortex 2021; 30:1499-1515. [PMID: 31647533 PMCID: PMC7132906 DOI: 10.1093/cercor/bhz181] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 06/05/2019] [Accepted: 07/09/2019] [Indexed: 11/20/2022] Open
Abstract
The extent of functional maturation and integration of nonproliferative neuronal precursors, becoming neurons in the adult murine piriform cortex, is largely unexplored. We thus questioned whether precursors eventually become equivalent to neighboring principal neurons or whether they represent a novel functional network element. Adult brain neuronal precursors and immature neurons (complex cells) were labeled in transgenic mice (DCX-DsRed and DCX-CreERT2 /flox-EGFP), and their cell fate was characterized with patch clamp experiments and morphometric analysis of axon initial segments. Young (DCX+) complex cells in the piriform cortex of 2- to 4-month-old mice received sparse synaptic input and fired action potentials at low maximal frequency, resembling neonatal principal neurons. Following maturation, the synaptic input detected on older (DCX−) complex cells was larger, but predominantly GABAergic, despite evidence of glutamatergic synaptic contacts. Furthermore, the rheobase current of old complex cells was larger and the maximal firing frequency was lower than those measured in neighboring age-matched principal neurons. The striking differences between principal neurons and complex cells suggest that the latter are a novel type of neuron and new coding element in the adult brain rather than simple addition or replacement for preexisting network components.
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Affiliation(s)
- Bruno Benedetti
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Dominik Dannehl
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Institute of Neuroanatomy, CBTM, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Richard König
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Simona Coviello
- BIOTECMED, Universitat de València and Center for Collaborative Research on Mental Health CIBERSAM, 46100 València, Spain
| | - Christina Kreutzer
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Pia Zaunmair
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Dominika Jakubecova
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Thomas M Weiger
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, 5020 Salzburg, Austria
| | - Juan Nacher
- BIOTECMED, Universitat de València and Center for Collaborative Research on Mental Health CIBERSAM, 46100 València, Spain
| | - Maren Engelhardt
- Institute of Neuroanatomy, CBTM, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Sébastien Couillard-Després
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, 5020 Salzburg, Austria.,Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
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Coviello S, Benedetti B, Jakubecova D, Belles M, Klimczak P, Gramuntell Y, Couillard-Despres S, Nacher J. PSA Depletion Induces the Differentiation of Immature Neurons in the Piriform Cortex of Adult Mice. Int J Mol Sci 2021; 22:5733. [PMID: 34072166 PMCID: PMC8198564 DOI: 10.3390/ijms22115733] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/12/2022] Open
Abstract
Immature neurons are maintained in cortical regions of the adult mammalian brain. In rodents, many of these immature neurons can be identified in the piriform cortex based on their high expression of early neuronal markers, such as doublecortin (DCX) and the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). This molecule plays critical roles in different neurodevelopmental events. Taking advantage of a DCX-CreERT2/Flox-EGFP reporter mice, we investigated the impact of targeted PSA enzymatic depletion in the piriform cortex on the fate of immature neurons. We report here that the removal of PSA accelerated the final development of immature neurons. This was revealed by a higher frequency of NeuN expression, an increase in the number of cells carrying an axon initial segment (AIS), and an increase in the number of dendrites and dendritic spines on the immature neurons. Taken together, our results demonstrated the crucial role of the PSA moiety in the protracted development of immature neurons residing outside of the neurogenic niches. More studies will be required to understand the intrinsic and extrinsic factors affecting PSA-NCAM expression to understand how the brain regulates the incorporation of these immature neurons to the established neuronal circuits of the adult brain.
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Affiliation(s)
- Simona Coviello
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Bruno Benedetti
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Dominika Jakubecova
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
| | - Maria Belles
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Patrycja Klimczak
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Yaiza Gramuntell
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
| | - Sebastien Couillard-Despres
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Institute of Experimental Neuroregeneration, Paracelsus Medical University, 5020 Salzburg, Austria; (B.B.); (D.J.)
- Austrian Cluster for Tissue Regeneration, 1200 Vienna, Austria
| | - Juan Nacher
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, 46100 Burjassot, Spain; (S.C.); (M.B.); (P.K.); (Y.G.)
- Spanish National Network for Research in Mental Health (CIBERSAM), 28029 Madrid, Spain
- Fundación Investigación Hospital Clínico de Valencia, INCLIVA, 46010 Valencia, Spain
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Cell Proliferation in the Piriform Cortex of Rats with Motor Cortex Ablation Treated with Growth Hormone and Rehabilitation. Int J Mol Sci 2021; 22:ijms22115440. [PMID: 34064044 PMCID: PMC8196768 DOI: 10.3390/ijms22115440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 05/18/2021] [Accepted: 05/19/2021] [Indexed: 12/17/2022] Open
Abstract
Traumatic brain injury represents one of the main health problems in developed countries. Growth hormone (GH) and rehabilitation have been claimed to significantly contribute to the recovery of lost motor function after acquired brain injury, but the mechanisms by which this occurs are not well understood. In this work, we have investigated cell proliferation in the piriform cortex (PC) of adult rats with ablation of the frontal motor cortex treated with GH and rehabilitation, in order to evaluate if this region of the brain, related to the sense of smell, could be involved in benefits of GH treatment. Male rats were either ablated the frontal motor cortex in the dominant hemisphere or sham-operated and treated with GH or vehicle at 35 days post-injury (dpi) for five days. At 36 dpi, all rats received daily injections of bromodeoxyuridine (BrdU) for four days. We assessed motor function through the paw-reaching-for-food task. GH treatment and rehabilitation at 35 dpi significantly improved the motor deficit caused by the injury and promoted an increase of cell proliferation in the PC ipsilateral to the injury, which could be involved in the improvement observed. Cortical ablation promoted a greater number of BrdU+ cells in the piriform cortex that was maintained long-term, which could be involved in the compensatory mechanisms of the brain after injury.
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11
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DCX + neuronal progenitors contribute to new oligodendrocytes during remyelination in the hippocampus. Sci Rep 2020; 10:20095. [PMID: 33208869 PMCID: PMC7674453 DOI: 10.1038/s41598-020-77115-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 11/02/2020] [Indexed: 02/07/2023] Open
Abstract
A pool of different types of neural progenitor cells resides in the adult hippocampus. Apart from doublecortin-expressing (DCX+) neuronal progenitor cells (NPCs), the hippocampal parenchyma also contains oligodendrocyte precursor cells (OPCs), which can differentiate into myelinating oligodendrocytes. It is not clear yet to what extent the functions of these different progenitor cell types overlap and how plastic these cells are in response to pathological processes. The aim of this study was to investigate whether hippocampal DCX+ NPCs can generate new oligodendrocytes under conditions in which myelin repair is required. For this, the cell fate of DCX-expressing NPCs was analyzed during cuprizone-induced demyelination and subsequent remyelination in two regions of the hippocampal dentate gyrus of DCX-CreERT2/Flox-EGFP transgenic mice. In this DCX reporter model, the number of GFP+ NPCs co-expressing Olig2 and CC1, a combination of markers typically found in mature oligodendrocytes, was significantly increased in the hippocampal DG during remyelination. In contrast, the numbers of GFP+PDGFRα+ cells, as well as their proliferation, were unaffected by de- or remyelination. During remyelination, a higher portion of newly generated BrdU-labeled cells were GFP+ NPCs and there was an increase in new oligodendrocytes derived from these proliferating cells (GFP+Olig2+BrdU+). These results suggest that DCX-expressing NPCs were able to contribute to the generation of mature oligodendrocytes during remyelination in the adult hippocampus.
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12
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Moura DMS, Brandão JA, Lentini C, Heinrich C, Queiroz CM, Costa MR. Evidence of Progenitor Cell Lineage Rerouting in the Adult Mouse Hippocampus After Status Epilepticus. Front Neurosci 2020; 14:571315. [PMID: 33071745 PMCID: PMC7530340 DOI: 10.3389/fnins.2020.571315] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 08/20/2020] [Indexed: 12/20/2022] Open
Abstract
Cell lineage in the adult hippocampus comprises multipotent and neuron-committed progenitors. In the present work, we fate-mapped neuronal progenitors using Dcx-CreERT2 and CAG-CAT-EGFP double-transgenic mice (cDCX/EGFP). We show that 3 days after tamoxifen-mediated recombination in cDCX/EGFP adult mice, GFP+ cells in the dentate gyrus (DG) co-expresses DCX and about 6% of these cells are proliferative neuronal progenitors. After 30 days, 20% of GFP+ generated from these progenitors differentiate into GFAP+ astrocytes. Unilateral intrahippocampal administration of the chemoconvulsants kainic acid (KA) or pilocarpine (PL) triggered epileptiform discharges and led to a significant increase in the number of GFP+ cells in both ipsi and contralateral DG. However, while PL favored the differentiation of neurons in both ipsi- and contralateral sides, KA stimulated neurogenesis only in the contralateral side. In the ipsilateral side, KA injection led to an unexpected increase of astrogliogenesis in the Dcx-lineage. We also observed a small number of GFP+/GFAP+ cells displaying radial-glia morphology ipsilaterally 3 days after KA administration, suggesting that some Dcx-progenitors could regress to a multipotent stage. The boosted neurogenesis and astrogliogenesis observed in the Dcx-lineage following chemoconvulsants administration correlated, respectively, with preservation or degeneration of the parvalbuminergic plexus in the DG. Increased inflammatory response, by contrast, was observed both in the DG showing increased neurogenesis or astrogliogenesis. Altogether, our data support the view that cell lineage progression in the adult hippocampus is not unidirectional and could be modulated by local network activity and GABA-mediated signaling.
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Affiliation(s)
- Daniela M S Moura
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | | | - Celia Lentini
- INSERM, Stem Cell and Brain Research Institute U1208, Univ Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Christophe Heinrich
- INSERM, Stem Cell and Brain Research Institute U1208, Univ Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Claudio M Queiroz
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Marcos R Costa
- Brain Institute, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil.,Unité INSERM 1167, RID-AGE-Risk Factors and Molecular Determinants of Aging-Related Diseases, Institut Pasteur de Lille, University of Lille, U1167-Excellence Laboratory LabEx DISTALZ, Lille, France
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13
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Heppt J, Wittmann MT, Schäffner I, Billmann C, Zhang J, Vogt-Weisenhorn D, Prakash N, Wurst W, Taketo MM, Lie DC. β-catenin signaling modulates the tempo of dendritic growth of adult-born hippocampal neurons. EMBO J 2020; 39:e104472. [PMID: 32929771 PMCID: PMC7604596 DOI: 10.15252/embj.2020104472] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 08/06/2020] [Accepted: 08/11/2020] [Indexed: 01/07/2023] Open
Abstract
In adult hippocampal neurogenesis, stem/progenitor cells generate dentate granule neurons that contribute to hippocampal plasticity. The establishment of a morphologically defined dendritic arbor is central to the functional integration of adult‐born neurons. We investigated the role of canonical Wnt/β‐catenin signaling in dendritogenesis of adult‐born neurons. We show that canonical Wnt signaling follows a biphasic pattern, with high activity in stem/progenitor cells, attenuation in immature neurons, and reactivation during maturation, and demonstrate that this activity pattern is required for proper dendrite development. Increasing β‐catenin signaling in maturing neurons of young adult mice transiently accelerated dendritic growth, but eventually produced dendritic defects and excessive spine numbers. In middle‐aged mice, in which protracted dendrite and spine development were paralleled by lower canonical Wnt signaling activity, enhancement of β‐catenin signaling restored dendritic growth and spine formation to levels observed in young adult animals. Our data indicate that precise timing and strength of β‐catenin signaling are essential for the correct functional integration of adult‐born neurons and suggest Wnt/β‐catenin signaling as a pathway to ameliorate deficits in adult neurogenesis during aging.
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Affiliation(s)
- Jana Heppt
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Marie-Theres Wittmann
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany.,Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Iris Schäffner
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Charlotte Billmann
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jingzhong Zhang
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Suzhou Institute of Biomedical Engineering and Technology (SIBET), Chinese Academy of Sciences, Suzhou, China
| | - Daniela Vogt-Weisenhorn
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Nilima Prakash
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany.,Hamm-Lippstadt University of Applied Sciences, Hamm, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, Neuherberg, Germany
| | - Makoto Mark Taketo
- Division of Experimental Therapeutics, Graduate School of Medicine, Kyoto University, Kyoto, Japan
| | - Dieter Chichung Lie
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
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14
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Rotheneichner P, Belles M, Benedetti B, König R, Dannehl D, Kreutzer C, Zaunmair P, Engelhardt M, Aigner L, Nacher J, Couillard-Despres S. Cellular Plasticity in the Adult Murine Piriform Cortex: Continuous Maturation of Dormant Precursors Into Excitatory Neurons. Cereb Cortex 2019; 28:2610-2621. [PMID: 29688272 PMCID: PMC5998952 DOI: 10.1093/cercor/bhy087] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Indexed: 11/14/2022] Open
Abstract
Neurogenesis in the healthy adult murine brain is based on proliferation and integration of stem/progenitor cells and is thought to be restricted to 2 neurogenic niches: the subventricular zone and the dentate gyrus. Intriguingly, cells expressing the immature neuronal marker doublecortin (DCX) and the polysialylated-neural cell adhesion molecule reside in layer II of the piriform cortex. Apparently, these cells progressively disappear along the course of ageing, while their fate and function remain unclear. Using DCX-CreERT2/Flox-EGFP transgenic mice, we demonstrate that these immature neurons located in the murine piriform cortex do not vanish in the course of aging, but progressively resume their maturation into glutamatergic (TBR1+, CaMKII+) neurons. We provide evidence for a putative functional integration of these newly differentiated neurons as indicated by the increase in perisomatic puncta expressing synaptic markers, the development of complex apical dendrites decorated with numerous spines and the appearance of an axonal initial segment. Since immature neurons found in layer II of the piriform cortex are generated prenatally and devoid of proliferative capacity in the postnatal cortex, the gradual maturation and integration of these cells outside of the canonical neurogenic niches implies that they represent a valuable, but nonrenewable reservoir for cortical plasticity.
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Affiliation(s)
- Peter Rotheneichner
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Maria Belles
- Neurobiology Unit, BIOTECMED, Universitat de València, Spanish Network for Mental Health Research CIBERSAM, INCLIVA, Valencia, Spain
| | - Bruno Benedetti
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Richard König
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Dominik Dannehl
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria.,Institute of Neuroanatomy, Center for Biomedicine and Medical Technology (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Christina Kreutzer
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Pia Zaunmair
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
| | - Maren Engelhardt
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology (CBTM), Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
| | - Juan Nacher
- Neurobiology Unit, BIOTECMED, Universitat de València, Spanish Network for Mental Health Research CIBERSAM, INCLIVA, Valencia, Spain
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Paracelsus Medical University, Salzburg, Austria
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15
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Lima da Cruz RV, Moulin TC, Petiz LL, Leão RN. A Single Dose of 5-MeO-DMT Stimulates Cell Proliferation, Neuronal Survivability, Morphological and Functional Changes in Adult Mice Ventral Dentate Gyrus. Front Mol Neurosci 2018; 11:312. [PMID: 30233313 PMCID: PMC6131656 DOI: 10.3389/fnmol.2018.00312] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 08/15/2018] [Indexed: 11/13/2022] Open
Abstract
The subgranular zone (SGZ) of dentate gyrus (DG) is one of the few regions in which neurogenesis is maintained throughout adulthood. It is believed that newborn neurons in this region encode temporal information about partially overlapping contextual memories. The 5-Methoxy-N,N-dimethyltryptamine (5-MeO-DMT) is a naturally occurring compound capable of inducing a powerful psychedelic state. Recently, it has been suggested that DMT analogs may be used in the treatment of mood disorders. Due to the strong link between altered neurogenesis and mood disorders, we tested whether 5-MeO-DMT is capable of increasing DG cell proliferation. We show that a single intracerebroventricular (ICV) injection of 5-MeO-DMT increases the number of Bromodeoxyuridine (BrdU+) cells in adult mice DG. Moreover, using a transgenic animal expressing tamoxifen-dependent Cre recombinase under doublecortin promoter, we found that 5 Meo-DMT treated mice had a higher number of newborn DG Granule cells (GC). We also showed that these DG GC have more complex dendritic morphology after 5-MeO-DMT. Lastly, newborn GC treated with 5-MeO-DMT, display shorter afterhyperpolarization (AHP) potentials and higher action potential (AP) threshold compared. Our findings show that 5-MeO-DMT affects neurogenesis and this effect may contribute to the known antidepressant properties of DMT-derived compounds.
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Affiliation(s)
| | - Thiago C Moulin
- Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lyvia Lintzmaier Petiz
- Neurodynamics Lab, Brain Institute, Federal University of the Rio Grande do Norte, Natal, Brazil
| | - Richardson N Leão
- Neurodynamics Lab, Brain Institute, Federal University of the Rio Grande do Norte, Natal, Brazil.,Developmental Genetics, Department of Neuroscience, Uppsala University, Uppsala, Sweden
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16
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Zhao ML, Chen SJ, Li XH, Wang LN, Chen F, Zhong SJ, Yang C, Sun SK, Li JJ, Dong HJ, Dong YQ, Wang Y, Chen C. Optical Depolarization of DCX-Expressing Cells Promoted Cognitive Recovery and Maturation of Newborn Neurons via the Wnt/β-Catenin Pathway. J Alzheimers Dis 2018; 63:303-318. [PMID: 29614674 DOI: 10.3233/jad-180002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Ming-Liang Zhao
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Shi-Jin Chen
- Department of Cardiology, Yichang Second People’s Hospital, Hubei, China
| | - Xiao-Hong Li
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Li-Na Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Feng Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Shi-Jiang Zhong
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Cheng Yang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Sheng-Kai Sun
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Jian-Jun Li
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Hua-Jiang Dong
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Yue-Qing Dong
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Yi Wang
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
| | - Chong Chen
- Tianjin Key Laboratory of Neurotrauma Repair, Pingjin Hospital Brain Center, Logistics University of Chinese People’s Armed Police Forces, Tianjin, China
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17
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Lobanova A, She R, Pieraut S, Clapp C, Maximov A, Denchi EL. Different requirements of functional telomeres in neural stem cells and terminally differentiated neurons. Genes Dev 2017; 31:639-647. [PMID: 28428263 PMCID: PMC5411705 DOI: 10.1101/gad.295402.116] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/16/2017] [Indexed: 11/30/2022]
Abstract
Here, Lobanova et al. examine the roles of telomeres at distinct stages of murine brain development by using lineage-specific genetic ablation of TRF2, an essential component of the shelterin complex that protects chromosome ends from the DNA damage response machinery. These results suggest that telomeres are dispensable in terminally differentiated neurons and provide mechanistic insight into cognitive abnormalities associated with aberrant telomere length in humans. Telomeres have been studied extensively in peripheral tissues, but their relevance in the nervous system remains poorly understood. Here, we examine the roles of telomeres at distinct stages of murine brain development by using lineage-specific genetic ablation of TRF2, an essential component of the shelterin complex that protects chromosome ends from the DNA damage response machinery. We found that functional telomeres are required for embryonic and adult neurogenesis, but their uncapping has surprisingly no detectable consequences on terminally differentiated neurons. Conditional knockout of TRF2 in post-mitotic immature neurons had virtually no detectable effect on circuit assembly, neuronal gene expression, and the behavior of adult animals despite triggering massive end-to-end chromosome fusions across the brain. These results suggest that telomeres are dispensable in terminally differentiated neurons and provide mechanistic insight into cognitive abnormalities associated with aberrant telomere length in humans.
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Affiliation(s)
- Anastasia Lobanova
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Robert She
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Simon Pieraut
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Charlie Clapp
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Anton Maximov
- Department of Neuroscience, The Scripps Research Institute, La Jolla, California 92037, USA
| | - Eros Lazzerini Denchi
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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18
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Distribution and fate of DCX/PSA-NCAM expressing cells in the adult mammalian cortex: A local reservoir for adult cortical neuroplasticity? ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s11515-016-1403-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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19
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Garrett L, Zhang J, Zimprich A, Niedermeier KM, Fuchs H, Gailus-Durner V, Hrabě de Angelis M, Vogt Weisenhorn D, Wurst W, Hölter SM. Conditional Reduction of Adult Born Doublecortin-Positive Neurons Reversibly Impairs Selective Behaviors. Front Behav Neurosci 2015; 9:302. [PMID: 26617501 PMCID: PMC4642364 DOI: 10.3389/fnbeh.2015.00302] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 10/29/2015] [Indexed: 11/27/2022] Open
Abstract
Adult neurogenesis occurs in the adult mammalian subventricular zone (SVZ) along the walls of the lateral ventricles and the subgranular zone (SGZ) of the hippocampal dentate gyrus. While a burgeoning body of research implicates adult neurogenesis in olfactory bulb (OB)- and hippocampal-related behaviors, the precise function continues to elude. To further assess the behavioral importance of adult neurogenesis, we herein generated a novel inducible transgenic mouse model of adult neurogenesis reduction where mice with CreERT2 under doublecortin (DCX) promoter control were crossed with mice where diphtheria toxin A (DTA) was driven by the Rosa26 promoter. Activation of DTA, through the administration of tamoxifen (TAM), results in a specific reduction of DCX+ immature neurons in both the hippocampal dentate gyrus and OB. We show that the decrease of DCX+ cells causes impaired social discrimination ability in both young adult (from 3 months) and middle aged (from 10 months) mice. Furthermore, these animals showed an age-independent altered coping behavior in the Forced Swim Test without clear changes in anxiety-related behavior. Notably, these behavior changes were reversible on repopulating the neurogenic zones with DCX+ cells on cessation of the TAM treatment, demonstrating the specificity of this effect. Overall, these results support the notion that adult neurogenesis plays a role in social memory and in stress coping but not necessarily in anxiety-related behavior.
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Affiliation(s)
- Lillian Garrett
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
| | - Jingzhong Zhang
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; Max Delbrück Zentrum für Molekulare Medizin Berlin, Germany
| | - Annemarie Zimprich
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
| | - Kristina M Niedermeier
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; Technische Universität München Freising-Weihenstephan, Germany
| | - Helmut Fuchs
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
| | - Valerie Gailus-Durner
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
| | - Martin Hrabě de Angelis
- German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; Technische Universität München Freising-Weihenstephan, Germany
| | - Daniela Vogt Weisenhorn
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; Technische Universität München Freising-Weihenstephan, Germany ; Deutsches Zentrum für Neurodegenerative Erkrankungen e. V. (DZNE) Munich, Germany ; Munich Cluster for Systems Neurology (SyNergy), Ludwig-Maximilians-Universität München Munich, Germany
| | - Sabine M Hölter
- Institute of Developmental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany ; German Mouse Clinic, Helmholtz Zentrum München, German Research Center for Environmental Health Neuherberg, Germany
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20
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A WNT1-regulated developmental gene cascade prevents dopaminergic neurodegeneration in adult En1 mice. Neurobiol Dis 2015; 82:32-45. [DOI: 10.1016/j.nbd.2015.05.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/18/2015] [Accepted: 05/27/2015] [Indexed: 11/17/2022] Open
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21
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Yang Y, Xie MX, Li JM, Hu X, Patrylo PR, Luo XG, Cai Y, Li Z, Yan XX. Prenatal genesis of layer II doublecortin expressing neurons in neonatal and young adult guinea pig cerebral cortex. Front Neuroanat 2015; 9:109. [PMID: 26321922 PMCID: PMC4530311 DOI: 10.3389/fnana.2015.00109] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/27/2015] [Indexed: 12/15/2022] Open
Abstract
Cells expressing doublecortin (DCX+) occur at cortical layer II, predominantly over the paleocortex in mice/rats, but also across the neocortex among larger mammals. Here, we explored the time of origin of these cells in neonatal and 2-month-old guinea pigs following prenatal BrdU pulse-chasing. In the neocortex, BrdU+ cells birth-dated at embryonic day 21 (E21), E28, and E35 laminated over the cortical plate with an inside-out order. In the piriform cortex, cells generated at E21 and E28 occurred with a greater density in layer II than III. Many cells were generated at later time points until birth, occurring in the cortex without a laminar preference. DCX+ cells in the neocortex and piriform cortex partially co-colocalized with BrdU (up to 7.5%) in the newborns after pulse-chasing from E21 to E49 and in the 2 month-old animals after pulse-chasing from E28 to E60/61, with higher rates seen among the E21-E35 groups. Together, layer II DCX+ cells in neonatal and young adult guinea pigs may be produced over a wide prenatal time window, but mainly during the early phases of corticogenesis. Our data also show an earlier establishment of the basic lamination in the piriform relative to neocortical areas in guinea pigs.
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Affiliation(s)
- Yan Yang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China ; Department of Nursing in Internal Medicine, Xiangtan Vocational and Technical College Xiangtan, China
| | - Mi-Xin Xie
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Jian-Ming Li
- Neuroscience Research Center, Changsha Medical University Changsha, China
| | - Xia Hu
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Peter R Patrylo
- Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University School of Medicine Carbondale, IL, USA
| | - Xue-Gang Luo
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Yan Cai
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Zhiyuan Li
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
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22
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Wu MV, Sahay A, Duman RS, Hen R. Functional differentiation of adult-born neurons along the septotemporal axis of the dentate gyrus. Cold Spring Harb Perspect Biol 2015; 7:a018978. [PMID: 26238355 DOI: 10.1101/cshperspect.a018978] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Over the past several decades, the proliferation and integration of adult-born neurons into existing hippocampal circuitry has been implicated in a wide range of behaviors, including novelty recognition, pattern separation, spatial learning, anxiety behaviors, and antidepressant response. In this review, we suggest that the diversity in behavioral requirements for new neurons may be partly caused by separate functional roles of individual neurogenic niches. Growing evidence shows that the hippocampal formation can be compartmentalized not only along the classic trisynaptic circuit, but also along a longitudinal septotemporal axis. We suggest that subpopulations of hippocampal adult-born neurons may be specialized for distinct mnemonic- or mood-related behavioral tasks. We will examine the literature supporting a functional and anatomical dissociation of the hippocampus along the longitudinal axis and discuss techniques to functionally dissect the roles of adult-born hippocampal neurons in these distinct subregions.
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Affiliation(s)
- Melody V Wu
- Department of Psychiatry, Columbia University, New York, New York 10027 Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York 10032
| | - Amar Sahay
- Center for Regenerative Medicine and Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts 02114 Harvard Stem Cell Institute and Harvard Medical School, Boston, Massachusetts 02115
| | - Ronald S Duman
- Department of Psychiatry, Yale University, New Haven, Connecticut 06520 Department of Neurobiology, Yale University, New Haven, Connecticut 06520
| | - René Hen
- Department of Psychiatry, Columbia University, New York, New York 10027 Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, New York 10032 Department of Neuroscience, Columbia University, New York, New York 10027 Department of Pharmacology, Columbia University, New York, New York 10027
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23
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Enikolopov G, Overstreet-Wadiche L, Ge S. Viral and transgenic reporters and genetic analysis of adult neurogenesis. Cold Spring Harb Perspect Biol 2015; 7:a018804. [PMID: 26238354 DOI: 10.1101/cshperspect.a018804] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Stem and progenitor cells of the developing and adult brain can be effectively identified and manipulated using reporter genes, introduced into transgenic reporter mouse lines or recombinant viruses. Such reporters rely on an ever-increasing variety of fluorescent proteins and a continuously expanding list of regulatory elements and of mouse lines engineered for cell- or time-specific recombination. An important extension of stem-cell-based genetic strategies is an opportunity to explore the properties of newly generated neurons and their contribution to synaptic plasticity. Here, we review available strategies for marking and quantifying various classes of stem and progenitor cells in the adult brain, genetically tracing their progeny, and studying the properties of stem cells and new neurons. We compare various experimental approaches to labeling and investigating stem cells and their progeny and discuss caveats and limitations inherent to each approach.
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Affiliation(s)
| | | | - Shaoyu Ge
- Department of Neurobiology and Behavior, Stony Brook University, Stony Brook, New York 11794
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Kandasamy M, Rosskopf M, Wagner K, Klein B, Couillard-Despres S, Reitsamer HA, Stephan M, Nguyen HP, Riess O, Bogdahn U, Winkler J, von Hörsten S, Aigner L. Reduction in subventricular zone-derived olfactory bulb neurogenesis in a rat model of Huntington's disease is accompanied by striatal invasion of neuroblasts. PLoS One 2015; 10:e0116069. [PMID: 25719447 PMCID: PMC4342015 DOI: 10.1371/journal.pone.0116069] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 12/05/2014] [Indexed: 01/18/2023] Open
Abstract
Huntington’s disease (HD) is an inherited progressive neurodegenerative disorder caused by an expanded CAG repeat in exon 1 of the huntingtin gene (HTT). The primary neuropathology of HD has been attributed to the preferential degeneration of medium spiny neurons (MSN) in the striatum. Reports on striatal neurogenesis have been a subject of debate; nevertheless, it should be considered as an endogenous attempt to repair the brain. The subventricular zone (SVZ) might offer a close-by region to supply the degenerated striatum with new cells. Previously, we have demonstrated that R6/2 mice, a widely used preclinical model representing an early onset HD, showed reduced olfactory bulb (OB) neurogenesis but induced striatal migration of neuroblasts without affecting the proliferation of neural progenitor cell (NPCs) in the SVZ. The present study revisits these findings, using a clinically more relevant transgenic rat model of late onset HD (tgHD rats) carrying the human HTT gene with 51 CAG repeats and mimicking many of the neuropathological features of HD seen in patients. We demonstrate that cell proliferation is reduced in the SVZ and OB of tgHD rats compared to WT rats. In the OB of tgHD rats, although cell survival was reduced, the frequency of neuronal differentiation was not altered in the granule cell layer (GCL) compared to the WT rats. However, an increased frequency of dopamenergic neuronal differentiation was noticed in the glomerular layer (GLOM) of tgHD rats. Besides this, we observed a selective proliferation of neuroblasts in the adjacent striatum of tgHD rats. There was no evidence for neuronal maturation and survival of these striatal neuroblasts. Therefore, the functional role of these invading neuroblasts still needs to be determined, but they might offer an endogenous alternative for stem or neuronal cell transplantation strategies.
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Affiliation(s)
- Mahesh Kandasamy
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Michael Rosskopf
- Department of Neurology, University Hospital Regensburg, Regensburg, Germany
| | - Katrin Wagner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Klein
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Sebastien Couillard-Despres
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria
| | - Herbert A. Reitsamer
- Department of Ophthalmology, SALK, Paracelsus Medical University, Salzburg, Austria
| | - Michael Stephan
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Huu Phuc Nguyen
- Department of Medical Genetics, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Department of Medical Genetics, University of Tübingen, Tübingen, Germany
| | - Ulrich Bogdahn
- Department of Neurology, University Hospital Regensburg, Regensburg, Germany
| | - Jürgen Winkler
- Division of Molecular Neurology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Stephan von Hörsten
- Experimental Therapy, Friedrich-Alexander-University Erlangen-Nurnberg, Erlangen, Germany
- * E-mail: (LA); (SvH)
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria
- Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
- * E-mail: (LA); (SvH)
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New Transgenic Technologies. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00003-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Sun MY, Yetman MJ, Lee TC, Chen Y, Jankowsky JL. Specificity and efficiency of reporter expression in adult neural progenitors vary substantially among nestin-CreER(T2) lines. J Comp Neurol 2014; 522:1191-208. [PMID: 24519019 DOI: 10.1002/cne.23497] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/16/2013] [Accepted: 10/25/2013] [Indexed: 12/16/2022]
Abstract
Transgenic lines expressing a controllable form of Cre recombinase have become valuable tools for manipulating gene expression in adult neural progenitors and their progeny. Neural progenitors express several proteins that distinguish them from mature neurons, and the promoters for these genes have been co-opted to produce selective transgene expression within this population. To date, nine CreER(T2) transgenic lines have been designed using the nestin promoter; however, only a subset are capable of eliciting expression within both neurogenic zones of the adult brain. Here we compare three such nestin-CreER(T2) lines to evaluate specificity of expression and efficiency of recombination. Each line was examined by using three different Cre reporter strains that varied in sensitivity. We found that all three nestin-CreER(T2) strains induced reporter expression within the main neurogenic areas, albeit to varying degrees depending on the reporter. Unexpectedly, we found that two of the three lines induced substantial reporter expression outside of neurogenic areas. These lines produced strong labeling in cerebellar granule neurons, with additional expression in the cortex, hippocampus, striatum, and thalamus. Reporter expression in the third nestin-CreER(T2) line was considerably more specific, but was also less efficient, labeling a smaller percentage of the target population than the other two drivers. Our findings suggest that each nestin-CreER(T2) line may best serve different experimental needs, depending on whether specificity or efficiency is of greatest concern. Our study further demonstrates that each new pair of driver and responder lines should be evaluated independently, as both components can significantly influence the resulting expression pattern.
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Affiliation(s)
- Min-Yu Sun
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, 77030
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Miura H, Scott JK, Harada S, Barlow LA. Sonic hedgehog-expressing basal cells are general post-mitotic precursors of functional taste receptor cells. Dev Dyn 2014; 243:1286-97. [PMID: 24590958 DOI: 10.1002/dvdy.24121] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 02/13/2014] [Accepted: 02/13/2014] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Taste buds contain ∼60 elongate cells and several basal cells. Elongate cells comprise three functional taste cell types: I, glial cells; II, bitter/sweet/umami receptor cells; and III, sour detectors. Although taste cells are continuously renewed, lineage relationships among cell types are ill-defined. Basal cells have been proposed as taste bud stem cells, a subset of which express Sonic hedgehog (Shh). However, Shh+ basal cells turn over rapidly suggesting that Shh+ cells are post-mitotic precursors of some or all taste cell types. RESULTS To fate map Shh-expressing cells, mice carrying ShhCreER(T2) and a high (CAG-CAT-EGFP) or low (R26RLacZ) efficiency reporter allele were given tamoxifen to activate Cre in Shh+ cells. Using R26RLacZ, lineage-labeled cells occur singly within buds, supporting a post-mitotic state for Shh+ cells. Using either reporter, we show that Shh+ cells differentiate into all three taste cell types, in proportions reflecting cell type ratios in taste buds (I > II > III). CONCLUSIONS Shh+ cells are not stem cells, but are post-mitotic, immediate precursors of taste cells. Shh+ cells differentiate into each of the three taste cell types, and the choice of a specific taste cell fate is regulated to maintain the proper ratio within buds.
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Affiliation(s)
- Hirohito Miura
- Department of Oral Physiology, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Kagoshima, Japan
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Khalaf-Nazzal R, Bruel-Jungerman E, Rio JP, Bureau J, Irinopoulou T, Sumia I, Roumegous A, Martin E, Olaso R, Parras C, Cifuentes-Diaz C, Francis F. Organelle and cellular abnormalities associated with hippocampal heterotopia in neonatal doublecortin knockout mice. PLoS One 2013; 8:e72622. [PMID: 24023755 PMCID: PMC3759370 DOI: 10.1371/journal.pone.0072622] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 07/11/2013] [Indexed: 11/18/2022] Open
Abstract
Heterotopic or aberrantly positioned cortical neurons are associated with epilepsy and intellectual disability. Various mouse models exist with forms of heterotopia, but the composition and state of cells developing in heterotopic bands has been little studied. Dcx knockout (KO) mice show hippocampal CA3 pyramidal cell lamination abnormalities, appearing from the age of E17.5, and mice suffer from spontaneous epilepsy. The Dcx KO CA3 region is organized in two distinct pyramidal cell layers, resembling a heterotopic situation, and exhibits hyperexcitability. Here, we characterized the abnormally organized cells in postnatal mouse brains. Electron microscopy confirmed that the Dcx KO CA3 layers at postnatal day (P) 0 are distinct and separated by an intermediate layer devoid of neuronal somata. We found that organization and cytoplasm content of pyramidal neurons in each layer were altered compared to wild type (WT) cells. Less regular nuclei and differences in mitochondria and Golgi apparatuses were identified. Each Dcx KO CA3 layer at P0 contained pyramidal neurons but also other closely apposed cells, displaying different morphologies. Quantitative PCR and immunodetections revealed increased numbers of oligodendrocyte precursor cells (OPCs) and interneurons in close proximity to Dcx KO pyramidal cells. Immunohistochemistry experiments also showed that caspase-3 dependent cell death was increased in the CA1 and CA3 regions of Dcx KO hippocampi at P2. Thus, unsuspected ultrastructural abnormalities and cellular heterogeneity may lead to abnormal neuronal function and survival in this model, which together may contribute to the development of hyperexcitability.
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Affiliation(s)
- Reham Khalaf-Nazzal
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Elodie Bruel-Jungerman
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Jean-Paul Rio
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Jocelyne Bureau
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Theano Irinopoulou
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Iffat Sumia
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Audrey Roumegous
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
| | - Elodie Martin
- Université Pierre et Marie Curie, Paris, France
- Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris, France
- INSERM UMRS 975, Paris, France
- CNRS UMR 7225, Paris, France
| | - Robert Olaso
- Plateforme de Transcriptomique, Laboratoire de Recherche Translationnelle, CEA/DSV/IG-Centre National de Génotypage, Evry, France
| | - Carlos Parras
- Université Pierre et Marie Curie, Paris, France
- Centre de Recherche de l'Institut du Cerveau et de la Moelle épinière, Paris, France
- INSERM UMRS 975, Paris, France
- CNRS UMR 7225, Paris, France
| | - Carmen Cifuentes-Diaz
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
- * E-mail: (FF); (CCD)
| | - Fiona Francis
- INSERM UMRS 839, Paris, France
- Université Pierre et Marie Curie, Paris, France
- Institut du Fer à Moulin, Paris, France
- * E-mail: (FF); (CCD)
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Immature doublecortin-positive hippocampal neurons are important for learning but not for remembering. J Neurosci 2013; 33:6603-13. [PMID: 23575857 DOI: 10.1523/jneurosci.3064-12.2013] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
It is now widely accepted that hippocampal neurogenesis underpins critical cognitive functions, such as learning and memory. To assess the behavioral importance of adult-born neurons, we developed a novel knock-in mouse model that allowed us to specifically and reversibly ablate hippocampal neurons at an immature stage. In these mice, the diphtheria toxin receptor (DTR) is expressed under control of the doublecortin (DCX) promoter, which allows for specific ablation of immature DCX-expressing neurons after administration of diphtheria toxin while leaving the neural precursor pool intact. Using a spatially challenging behavioral test (a modified version of the active place avoidance test), we present direct evidence that immature DCX-expressing neurons are required for successful acquisition of spatial learning, as well as reversal learning, but are not necessary for the retrieval of stored long-term memories. Importantly, the observed learning deficits were rescued as newly generated immature neurons repopulated the granule cell layer upon termination of the toxin treatment. Repeat (or cyclic) depletion of immature neurons reinstated behavioral deficits if the mice were challenged with a novel task. Together, these findings highlight the potential of stimulating neurogenesis as a means to enhance learning.
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Kohman RA, Rhodes JS. Neurogenesis, inflammation and behavior. Brain Behav Immun 2013; 27:22-32. [PMID: 22985767 PMCID: PMC3518576 DOI: 10.1016/j.bbi.2012.09.003] [Citation(s) in RCA: 266] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/23/2012] [Accepted: 09/04/2012] [Indexed: 12/12/2022] Open
Abstract
Before the 1990s it was widely believed that the adult brain was incapable of regenerating neurons. However, it is now established that new neurons are continuously produced in the dentate gyrus of the hippocampus and olfactory bulb throughout life. The functional significance of adult neurogenesis is still unclear, but it is widely believed that the new neurons contribute to learning and memory and/or maintenance of brain regions by replacing dead or dying cells. Many different factors are known to regulate adult neurogenesis including immune responses and signaling molecules released by immune cells in the brain. While immune activation (i.e., enlargement of microglia, release of cytokines) within the brain is commonly viewed as a harmful event, the impact of immune activation on neural function is highly dependent on the form of the immune response as microglia and other immune-reactive cells in the brain can support or disrupt neural processes depending on the phenotype and behavior of the cells. For instance, microglia that express an inflammatory phenotype generally reduce cell proliferation, survival and function of new neurons whereas microglia displaying an alternative protective phenotype support adult neurogenesis. The present review summarizes current understanding of the role of new neurons in cognition and behavior, with an emphasis on the immune system's ability to influence adult hippocampal neurogenesis during both an inflammatory episode and in the healthy uninjured brain. It has been proposed that some of the cognitive deficits associated with inflammation may in part be related to inflammation-induced reductions in adult hippocampal neurogenesis. Elucidating how the immune system contributes to the regulation of adult neurogenesis will help in predicting the impact of immune activation on neural plasticity and potentially facilitate the discovery of treatments to preserve neurogenesis in conditions characterized by chronic inflammation.
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Garcia I, Kim C, Arenkiel BR. Genetic strategies to investigate neuronal circuit properties using stem cell-derived neurons. Front Cell Neurosci 2012; 6:59. [PMID: 23264761 PMCID: PMC3524522 DOI: 10.3389/fncel.2012.00059] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Accepted: 11/30/2012] [Indexed: 01/28/2023] Open
Abstract
The mammalian brain is anatomically and functionally complex, and prone to diverse forms of injury and neuropathology. Scientists have long strived to develop cell replacement therapies to repair damaged and diseased nervous tissue. However, this goal has remained unrealized for various reasons, including nascent knowledge of neuronal development, the inability to track and manipulate transplanted cells within complex neuronal networks, and host graft rejection. Recent advances in embryonic stem cell (ESC) and induced pluripotent stem cell (iPSC) technology, alongside novel genetic strategies to mark and manipulate stem cell-derived neurons, now provide unprecedented opportunities to investigate complex neuronal circuits in both healthy and diseased brains. Here, we review current technologies aimed at generating and manipulating neurons derived from ESCs and iPSCs toward investigation and manipulation of complex neuronal circuits, ultimately leading to the design and development of novel cell-based therapeutic approaches.
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Affiliation(s)
- Isabella Garcia
- Program in Developmental Biology, Baylor College of Medicine Houston, TX, USA ; Medical Scientist Training Program, Baylor College of Medicine Houston, TX, USA
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Pan A, Li M, Gao JY, Xue ZQ, Li Z, Yuan XY, Luo DW, Luo XG, Yan XX. Experimental epidural hematoma causes cerebral infarction and activates neocortical glial and neuronal genesis in adult guinea pigs. J Neurosci Res 2012; 91:249-61. [DOI: 10.1002/jnr.23148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2012] [Revised: 08/26/2012] [Accepted: 09/02/2012] [Indexed: 12/16/2022]
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Spampanato J, Sullivan RK, Turpin FR, Bartlett PF, Sah P. Properties of doublecortin expressing neurons in the adult mouse dentate gyrus. PLoS One 2012; 7:e41029. [PMID: 22957010 PMCID: PMC3434174 DOI: 10.1371/journal.pone.0041029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Accepted: 06/16/2012] [Indexed: 12/04/2022] Open
Abstract
The dentate gyrus is a neurogenic zone where neurons continue to be born throughout life, mature and integrate into the local circuitry. In adults, this generation of new neurons is thought to contribute to learning and memory formation. As newborn neurons mature, they undergo a developmental sequence in which different stages of development are marked by expression of different proteins. Doublecortin (DCX) is an early marker that is expressed in immature granule cells that are beginning migration and dendritic growth but is turned off before neurons reach maturity. In the present study, we use a mouse strain in which enhanced green fluorescent protein (EGFP) is expressed under the control of the DCX promoter. We show that these neurons have high input resistances and some cells can discharge trains of action potentials. In mature granule cells, action potentials are followed by a slow afterhyperpolarization that is absent in EGFP-positive neurons. EGFP-positive neurons had a lower spine density than mature neurons and stimulation of either the medial or lateral perforant pathway activated dual component glutamatergic synapses that had both AMPA and NMDA receptors. NMDA receptors present at these synapses had slow kinetics and were blocked by ifenprodil, indicative of high GluN2B subunit content. These results show that EGFP-positive neurons in the DCX-EGFP mice are functionally immature both in their firing properties and excitatory synapses.
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Affiliation(s)
- Jay Spampanato
- The Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Robert K. Sullivan
- The Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Fabrice R. Turpin
- The Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Perry F. Bartlett
- The Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Pankaj Sah
- The Queensland Brain Institute, The University of Queensland, Brisbane, Australia
- * E-mail:
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Vande Velde G, Couillard-Després S, Aigner L, Himmelreich U, van der Linden A. In situ labeling and imaging of endogenous neural stem cell proliferation and migration. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2012; 4:663-79. [PMID: 22933366 DOI: 10.1002/wnan.1192] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Endogenous neural stem cells (eNSCs) reside in defined regions of the adult brain and have the potential to generate new brain cells, including neurons. Stimulation of adult neurogenesis presents an enormous potential for regenerative therapies in the central nervous system. However, the methods used to monitor the proliferation, migration, differentiation, and functional integration of eNSCs and their progeny are often invasive and limited in studying dynamic processes. To overcome this limitation, novel techniques and contrast mechanisms for in vivo imaging of neurogenesis have recently been developed and successfully applied. In vivo labeling of endogenous neuronal progenitor cells in situ with contrast agents or tracers enables longitudinal visualization of their proliferation and/or migration. Labeling of these cells with magnetic nanoparticles has proven to be very useful for tracking neuroblast migration with MRI. Alternatively, genetic labeling using reporter gene technology has been demonstrated for optical and MR imaging, leading to the development of powerful tools for in vivo optical imaging of neurogenesis. More recently, the iron storage protein ferritin has been used as an endogenously produced MRI contrast agent to monitor neuroblast migration. The use of specific promoters for neuronal progenitor cell imaging increases the specificity for visualizing neurogenesis. Further improvements of detection sensitivity and neurogenesis-specific contrast are nevertheless required for each of these imaging techniques to further improve the already high utility of this toolbox for preclinical neurogenesis research.
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Affiliation(s)
- Greetje Vande Velde
- Biomedical MRI Unit/Molecular Small Animal Imaging Center, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Flanders, Belgium
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Chronic lead exposure reduces doublecortin-expressing immature neurons in young adult guinea pig cerebral cortex. BMC Neurosci 2012; 13:82. [PMID: 22812564 PMCID: PMC3444321 DOI: 10.1186/1471-2202-13-82] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 07/06/2012] [Indexed: 01/08/2023] Open
Abstract
Background Chronic lead (Pb) poisoning remains an environmental risk especially for the pediatric population, and it may affect brain development. Immature neurons expressing doublecortin (DCX+) exist around cortical layer II in various mammals, including adult guinea pigs and humans. Using young adult guinea pigs as an experimental model, the present study explored if chronic Pb exposure affects cortical DCX + immature neurons and those around the subventricular and subgranular zones (SVZ, SGZ). Results Two month-old guinea pigs were treated with 0.2% lead acetate in drinking water for 2, 4 and 6 months. Blood Pb levels in these animals reached 10.27 ± 0.62, 16.25 ± 0.78 and 19.03 ± 0.86 μg/dL at the above time points, respectively, relative to ~3 μg/dL in vehicle controls. The density of DCX + neurons was significantly reduced around cortical layer II, SVZ and SGZ in Pb-treated animals surviving 4 and 6 months relative to controls. Bromodeoxyuridine (BrdU) pulse-chasing studies failed to find cellular colocalization of this DNA synthesis indicator in DCX + cells around layer II in Pb-treated and control animals. These cortical immature neurons were not found to coexist with active caspase-3 or Fluoro-Jade C labeling. Conclusion Chronic Pb exposure can lead to significant reduction in the number of the immature neurons around cortical layer II and in the conventional neurogenic sites in young adult guinea pigs. No direct evidence could be identified to link the reduced cortical DCX expression with alteration in local neurogenesis or neuronal death.
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Werner L, Müller-Fielitz H, Ritzal M, Werner T, Rossner M, Schwaninger M. Involvement of doublecortin-expressing cells in the arcuate nucleus in body weight regulation. Endocrinology 2012; 153:2655-64. [PMID: 22492306 DOI: 10.1210/en.2011-1760] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Hypothalamic functions, including feeding behavior, show a high degree of plasticity throughout life. Doublecortin (DCX) is a marker of plasticity and neuronal migration expressed in the hypothalamus. Therefore, we wanted to map the fate of DCX(+) cells in the arcuate nucleus (ARC) of the hypothalamus. For this purpose, we generated a BAC transgenic mouse line that expresses the inducible recombinase CreER(T2) under control of the DCX locus. Crossing this line with the Rosa26 or Ai14 reporter mouse lines, we found reporter(+) cells in the ARC upon tamoxifen treatment. They were born prenatally and expressed both DCX and the plasticity marker TUC-4. Immediately after labeling, reporter(+) cells had an enlarged soma that normalized over time, suggesting morphological remodeling. Reporter(+) cells expressed β-endorphin and BSX, neuronal markers of the feeding circuit. Furthermore, leptin treatment led to phosphorylation of STAT3 in reporter(+) cells in accordance with the concept that they are part of the feeding circuits. Indeed, we found a negative correlation between the number of reporter(+) cells and body weight and epididymal fat pads. Our data suggest that DCX(+) cells in the ARC represent a cellular correlate of plasticity that is involved in controlling energy balance in adult mice.
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Affiliation(s)
- Lars Werner
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, 23538 Lübeck, Germany
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Bonfanti L, Nacher J. New scenarios for neuronal structural plasticity in non-neurogenic brain parenchyma: the case of cortical layer II immature neurons. Prog Neurobiol 2012; 98:1-15. [PMID: 22609484 DOI: 10.1016/j.pneurobio.2012.05.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2011] [Revised: 04/25/2012] [Accepted: 05/08/2012] [Indexed: 11/20/2022]
Abstract
The mammalian central nervous system, due to its interaction with the environment, must be endowed with plasticity. Conversely, the nervous tissue must be substantially static to ensure connectional invariability. Structural plasticity can be viewed as a compromise between these requirements. In adult mammals, brain structural plasticity is strongly reduced with respect to other animal groups in the phylogenetic tree. It persists under different forms, which mainly consist of remodeling of neuronal shape and connectivity, and, to a lesser extent, the production of new neurons. Adult neurogenesis is mainly restricted within two neurogenic niches, yet some gliogenic and neurogenic processes also occur in the so-called non-neurogenic tissue, starting from parenchymal progenitors. In this review we focus on a population of immature, non-newly generated neurons in layer II of the cerebral cortex, which were previously thought to be newly generated since they heavily express the polysialylated form of the neural cell adhesion molecule and doublecortin. These unusual neurons exhibit characteristics defining an additional type of structural plasticity, different from either synaptic plasticity or adult neurogenesis. Evidences concerning their morphology, antigenic features, ultrastructure, phenotype, origin, fate, and reaction to different kind of stimulations are gathered and analyzed. Their possible role is discussed in the context of an enriched complexity and heterogeneity of mammalian brain structural plasticity.
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Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano (TO), and Department of Veterinary Morphophysiology, University of Turin, Turin, Italy.
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SoxC transcription factors are required for neuronal differentiation in adult hippocampal neurogenesis. J Neurosci 2012; 32:3067-80. [PMID: 22378879 DOI: 10.1523/jneurosci.4679-11.2012] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Neural stem cells (NSCs) generate new hippocampal dentate granule neurons throughout adulthood. The genetic programs controlling neuronal differentiation of adult NSCs are only poorly understood. Here we show that, in the adult mouse hippocampus, expression of the SoxC transcription factors Sox4 and Sox11 is initiated around the time of neuronal commitment of adult NSCs and is maintained in immature neurons. Overexpression of Sox4 and Sox11 strongly promotes in vitro neurogenesis from adult NSCs, whereas ablation of Sox4/Sox11 prevents in vitro and in vivo neurogenesis from adult NSCs. Moreover, we demonstrate that SoxC transcription factors target the promoters of genes that are induced on neuronal differentiation of adult NSCs. Finally, we show that reprogramming of astroglia into neurons is dependent on the presence of SoxC factors. These data identify SoxC proteins as essential contributors to the genetic network controlling neuronal differentiation in adult neurogenesis and neuronal reprogramming of somatic cells.
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Imayoshi I, Sakamoto M, Kageyama R. Genetic methods to identify and manipulate newly born neurons in the adult brain. Front Neurosci 2011; 5:64. [PMID: 21562606 PMCID: PMC3087966 DOI: 10.3389/fnins.2011.00064] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Accepted: 04/19/2011] [Indexed: 12/12/2022] Open
Abstract
Although mammalian neurogenesis is mostly completed by the perinatal period, new neurons are continuously generated in the subventricular zone of the lateral ventricle and the subgranular zone of the hippocampal dentate gyrus. Since the discovery of adult neurogenesis, many extensive studies have been performed on various aspects of adult neurogenesis, including proliferation and fate-specification of adult neural stem cells, and the migration, maturation and synaptic integration of newly born neurons. Furthermore, recent research has shed light on the intensive contribution of adult neurogenesis to olfactory-related and hippocampus-mediated brain functions. The field of adult neurogenesis progressed tremendously thanks to technical advances that facilitate the identification and selective manipulation of newly born neurons among billions of pre-existing neurons in the adult central nervous system. In this review, we introduce recent advances in the methodologies for visualizing newly generated neurons and manipulating neurogenesis in the adult brain. Particularly, the application of site-specific recombinases and Tet inducible system in combination with transgenic or gene targeting strategy is discussed in further detail.
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Affiliation(s)
- Itaru Imayoshi
- Institute for Virus Research, Kyoto University Kyoto, Japan
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