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Waichman TV, Vercesi ML, Berardino AA, Beckel MS, Giacomini D, Rasetto NB, Herrero M, Di Bella DJ, Arlotta P, Schinder AF, Chernomoretz A. scX: a user-friendly tool for scRNAseq exploration. Bioinform Adv 2024; 4:vbae062. [PMID: 38779177 PMCID: PMC11109472 DOI: 10.1093/bioadv/vbae062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 03/06/2024] [Accepted: 04/30/2024] [Indexed: 05/25/2024]
Abstract
Motivation Single-cell RNA sequencing (scRNAseq) has transformed our ability to explore biological systems. Nevertheless, proficient expertise is essential for handling and interpreting the data. Results In this article, we present scX, an R package built on the Shiny framework that streamlines the analysis, exploration, and visualization of single-cell experiments. With an interactive graphic interface, implemented as a web application, scX provides easy access to key scRNAseq analyses, including marker identification, gene expression profiling, and differential gene expression analysis. Additionally, scX seamlessly integrates with commonly used single-cell Seurat and SingleCellExperiment R objects, resulting in efficient processing and visualization of varied datasets. Overall, scX serves as a valuable and user-friendly tool for effortless exploration and sharing of single-cell data, simplifying some of the complexities inherent in scRNAseq analysis. Availability and implementation Source code can be downloaded from https://github.com/chernolabs/scX. A docker image is available from dockerhub as chernolabs/scx.
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Affiliation(s)
- Tomás V Waichman
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - M L Vercesi
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - Ariel A Berardino
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, CP1405, Argentina
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
| | - Maximiliano S Beckel
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, CP1405, Argentina
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
| | - Damiana Giacomini
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - Natalí B Rasetto
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - Magalí Herrero
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - Daniela J Di Bella
- Department of Stem Cells and Regenerative Biology, Harvard University, Cambridge, MA 02138, United States
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02138, United States
| | - Paola Arlotta
- Department of Stem Cells and Regenerative Biology, Harvard University, Cambridge, MA 02138, United States
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA 02138, United States
| | - Alejandro F Schinder
- Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Buenos Aires, CP1405, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, CP1405, Argentina
| | - Ariel Chernomoretz
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, CP1405, Argentina
- Departamento de Física, FCEN, Universidad de Buenos Aires, Buenos Aires, CP1428, Argentina
- INFINA, UBA-CONICET, Buenos Aires, CP 1428, Argentina
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Waichman TV, Vercesi ML, Berardino AA, Beckel MS, Giacomini D, Rasetto NB, Herrero M, Di Bella DJ, Arlotta P, Schinder AF, Chernomoretz A. scX: A user-friendly tool for scRNA-seq exploration. ArXiv 2024:arXiv:2311.00012v2. [PMID: 37961742 PMCID: PMC10635291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Single-cell RNA sequencing (scRNA-seq) has transformed our ability to explore biological systems. Nevertheless, proficient expertise is essential for handling and interpreting the data. In this paper, we present scX, an R package built on the Shiny framework that streamlines the analysis, exploration, and visualization of single-cell experiments. With an interactive graphic interface, implemented as a web application, scX provides easy access to key scRNAseq analyses, including marker identification, gene expression profiling, and differential gene expression analysis. Additionally, scX seamlessly integrates with commonly used single-cell Seurat and Single-CellExperiment R objects, resulting in efficient processing and visualization of varied datasets. Overall, scX serves as a valuable and user-friendly tool for effortless exploration and sharing of single-cell data, simplifying some of the complexities inherent in scRNAseq analysis.
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Affiliation(s)
- Tomás Vega Waichman
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - M Luz Vercesi
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - Ariel A Berardino
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
| | - Maximiliano S Beckel
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
| | - Damiana Giacomini
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - Natalí B Rasetto
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - Magalí Herrero
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - Daniela J Di Bella
- Dept. of Stem Cells and Regenerative Biology, Harvard University & Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Paola Arlotta
- Dept. of Stem Cells and Regenerative Biology, Harvard University & Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Alejandro F Schinder
- Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, C1425 FQB, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
| | - Ariel Chernomoretz
- Integrative Systems Biology Lab, Leloir Institute, Buenos Aires, C1405 BWE, Argentina
- Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Instituto de Física de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
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Rasetto NB, Giacomini D, Berardino AA, Waichman TV, Beckel MS, Di Bella DJ, Brown J, Davies-Sala MG, Gerhardinger C, Lie DC, Arlotta P, Chernomoretz A, Schinder AF. Transcriptional dynamics orchestrating the development and integration of neurons born in the adult hippocampus. bioRxiv 2024:2023.11.03.565477. [PMID: 38260428 PMCID: PMC10802403 DOI: 10.1101/2023.11.03.565477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The adult hippocampus generates new granule cells (aGCs) that exhibit distinct functional capabilities along development, conveying a unique form of plasticity to the preexisting circuits. While early differentiation of adult radial glia-like neural stem cells (RGL) has been studied extensively, the molecular mechanisms guiding the maturation of postmitotic neurons remain unknown. Here, we used a precise birthdating strategy to follow newborn aGCs along differentiation using single-nuclei RNA sequencing (snRNA-seq). Transcriptional profiling revealed a continuous trajectory from RGLs to mature aGCs, with multiple sequential immature stages bearing increasing levels of effector genes supporting growth, excitability and synaptogenesis. Remarkably, four discrete cellular states were defined by the expression of distinct sets of transcription factors (TFs): quiescent neural stem cells, proliferative progenitors, postmitotic immature aGCs, and mature aGCs. The transition from immature to mature aCGs involved a transcriptional switch that shutdown molecular cascades promoting cell growth, such as the SoxC family of TFs, to activate programs controlling neuronal homeostasis. Indeed, aGCs overexpressing Sox4 or Sox11 remained stalled at the immature state. Our results unveil precise molecular mechanisms driving adult neural stem cells through the pathway of neuronal differentiation.
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Mugnaini M, Trinchero MF, Schinder AF, Piatti VC, Kropff E. Unique potential of immature adult-born neurons for the remodeling of CA3 spatial maps. Cell Rep 2023; 42:113086. [PMID: 37676761 DOI: 10.1016/j.celrep.2023.113086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/30/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
Mammalian hippocampal circuits undergo extensive remodeling through adult neurogenesis. While this process has been widely studied, the specific contribution of adult-born granule cells (aGCs) to spatial operations in the hippocampus remains unknown. Here, we show that optogenetic activation of 4-week-old (young) aGCs in free-foraging mice produces a non-reversible reconfiguration of spatial maps in proximal CA3 while rarely evoking neural activity. Stimulation of the same neuronal cohort on subsequent days recruits CA3 neurons with increased efficacy but fails to induce further remapping. In contrast, stimulation of 8-week-old (mature) aGCs can reliably activate CA3 cells but produces no alterations in spatial maps. Our results reveal a unique role of young aGCs in remodeling CA3 representations, a potential that can be depleted and is lost with maturation. This ability could contribute to generate orthogonalized downstream codes supporting pattern separation.
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Affiliation(s)
- Matías Mugnaini
- Department of Physiology, Molecular and Cellular Biology Dr. Héctor Maldonado, Faculty of Exact and Natural Science, University of Buenos Aires, Buenos Aires C1428EGA, Argentina; Laboratory of Physiology and Algorithms of the Brain, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina
| | - Mariela F Trinchero
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
| | - Verónica C Piatti
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
| | - Emilio Kropff
- Laboratory of Physiology and Algorithms of the Brain, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
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Groisman AI, Aguilar-Arredondo A, Giacomini D, Schinder AF. Neuroligin-2 controls the establishment of fast GABAergic transmission in adult-born granule cells. Hippocampus 2023; 33:424-441. [PMID: 36709408 DOI: 10.1002/hipo.23505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/19/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
GABAergic inhibition is critical for the precision of neuronal spiking and the homeostatic regulation of network activity in the brain. Adult neurogenesis challenges network homeostasis because new granule cells (GCs) integrate continuously in the functional dentate gyrus. While developing, adult-born GCs undergo a transient state of enhanced excitability due to the delayed maturation of perisomatic GABAergic inhibition by parvalbumin interneurons (PV-INs). The mechanisms underlying this delayed synaptic maturation remain unknown. We examined the morphology and function of synapses formed by PV-INs onto new GCs over a 2-month interval in young adult mice, and investigated the influence of the synaptic adhesion molecule neuroligin-2 (NL2). Perisomatic appositions of PV-IN terminals onto new GCs were conspicuous at 2 weeks and continued to grow in size to reach a plateau over the fourth week. Postsynaptic knockdown of NL2 by expression of a short-hairpin RNA (shNL2) in new GCs resulted in smaller size of synaptic contacts, reduced area of perisomatic appositions of the vesicular GABA transporter VGAT, and the number of presynaptic active sites. GCs expressing shNL2 displayed spontaneous GABAergic responses with decreased frequency and amplitude, as well as slower kinetics compared to control GCs. In addition, postsynaptic responses evoked by optogenetic stimulation of PV-INs exhibited slow kinetics, increased paired-pulse ratio and coefficient of variation in GCs with NL2 knockdown, suggesting a reduction in the number of active synapses as well as in the probability of neurotransmitter release (Pr ). Our results demonstrate that synapses formed by PV-INs on adult-born GCs continue to develop beyond the point of anatomical growth, and require NL2 for the structural and functional maturation that accompanies the conversion into fast GABAergic transmission.
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Affiliation(s)
- Ayelén I Groisman
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | | | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
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Trinchero MF, Giacomini D, Schinder AF. Dynamic interplay between GABAergic networks and developing neurons in the adult hippocampus. Curr Opin Neurobiol 2021; 69:124-130. [PMID: 33873060 DOI: 10.1016/j.conb.2021.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/10/2021] [Accepted: 03/14/2021] [Indexed: 01/07/2023]
Abstract
Neurogenesis is a powerful mechanism for structural and functional remodeling that occurs in restricted areas of the adult brain. Although different neurotransmitters regulate various aspects of the progression from neural stem cell quiescence to neuronal maturation, GABA is the main player. The developmental switch from excitation to inhibition combined with a heterogeneous population of GABAergic interneurons that target different subcellular compartments provides multiple points for the regulation of development and function of new neurons. This complexity is enhanced by feedback and feedforward networks that act as sensors and controllers of circuit activity, impinging directly or indirectly onto developing granule cells and, subsequently, on mature neurons. Newly generated granule cells ultimately connect with input and output partners in a manner that is largely sculpted by the activity of local circuits.
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Affiliation(s)
- Mariela F Trinchero
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Damiana Giacomini
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina.
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7
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Groisman AI, Yang SM, Schinder AF. Differential Coupling of Adult-Born Granule Cells to Parvalbumin and Somatostatin Interneurons. Cell Rep 2021; 30:202-214.e4. [PMID: 31914387 PMCID: PMC7011182 DOI: 10.1016/j.celrep.2019.12.005] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/16/2019] [Accepted: 11/27/2019] [Indexed: 12/29/2022] Open
Abstract
A strong GABAergic tone imposes sparse levels of activity in the dentate gyrus of the hippocampus. This balance is challenged by the addition of new granule cells (GCs) with high excitability. How developing GCs integrate within local inhibitory networks remains unknown. We used optogenetics to study synaptogenesis between new GCs and GABAergic interneurons expressing parvalbumin (PV-INs) and somatostatin (SST-INs). PV-INs target the soma, and synapses become mature after 6 weeks. This transition is accelerated by exposure to an enriched environment. PV-INs exert efficient control of GC spiking and participate in both feedforward and feedback loops, a mechanism that would favor lateral inhibition and sparse coding. SST-INs target the dendrites, and synapses mature after 8 weeks. Outputs from GCs onto PV-INs develop faster than those onto SST-INs. Our results reveal a long-lasting transition wherein adult-born neurons remain poorly coupled to inhibition, which might enhance activity-dependent plasticity of input and output synapses. Groisman et al. examine the integration of adult-born granule cells (GCs) to inhibitory networks of the adult hippocampus. Synapse maturation is remarkably slow for parvalbumin and somatostatin interneurons, both for connections toward and from GCs. Inhibition controls the activity of new GCs late in development.
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Affiliation(s)
- Ayelén I Groisman
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - Sung M Yang
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Av. Patricias Argentinas 435, C1405BWE Buenos Aires, Argentina.
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Trinchero MF, Schinder AF. GABAergic Interneurons Control Adult Neurogenesis but Astrocytes Have the Last Word. Neuron 2020; 108:226-228. [PMID: 33120019 DOI: 10.1016/j.neuron.2020.09.041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Adult neurogenesis depends on the decision of neural stem cells to leave quiescence and become neurons. In this issue, Asrican et al. show that the neuropeptide cholecystokinin released by interneurons promotes the neuronal fate through astrocytic signaling.
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Affiliation(s)
- Mariela F Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
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Trinchero MF, Herrero M, Schinder AF. Rejuvenating the Brain With Chronic Exercise Through Adult Neurogenesis. Front Neurosci 2019; 13:1000. [PMID: 31619959 PMCID: PMC6759473 DOI: 10.3389/fnins.2019.01000] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/04/2019] [Indexed: 12/22/2022] Open
Abstract
The aging brain presents a general decline in plasticity that also affects hippocampal neurogenesis. Besides the well-known reduction in the rate of neuronal generation, development of new neurons is largely delayed in the aging brain. We have recently shown that this slow development is accelerated when middle-aged mice perform voluntary exercise in a running wheel. It is unclear whether the effects of exercise on neurogenic plasticity are persistent in time in a manner that might influence neuronal cohorts generated over an extended time span. To clarify these issues, we examined the effects of exercise length in 3-week-old neurons and found that their development is accelerated only when running occurs for long (3-4 weeks) but not short periods (1 week). Furthermore, chronic running acted with similar efficiency on neurons that were born at the onset, within, or at the end of the exercise period, lasting until 3 months. Interestingly, no effects were observed on neurons born 1 month after exercise had ended. Our results indicate that multiple neuronal cohorts born throughout the exercise span integrate very rapidly in the aging brain, such that the effects of running will accumulate and expand network assembly promoted by neurogenesis. These networks are likely to be more complex than those assembled in a sedentary mouse due to the faster and more efficient integration of new neurons.
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Affiliation(s)
- Mariela F Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Magalí Herrero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
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Trinchero MF, Herrero M, Monzón-Salinas MC, Schinder AF. Experience-Dependent Structural Plasticity of Adult-Born Neurons in the Aging Hippocampus. Front Neurosci 2019; 13:739. [PMID: 31379489 PMCID: PMC6651579 DOI: 10.3389/fnins.2019.00739] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/02/2019] [Indexed: 12/28/2022] Open
Abstract
Synaptic modification in cortical structures underlies the acquisition of novel information that results in learning and memory formation. In the adult dentate gyrus, circuit remodeling is boosted by the generation of new granule cells (GCs) that contribute to specific aspects of memory encoding. These forms of plasticity decrease in the aging brain, where both the rate of adult neurogenesis and the speed of morphological maturation of newly generated neurons decline. In the young-adult brain, a brief novel experience accelerates the integration of new neurons. The extent to which such degree of plasticity is preserved in the aging hippocampus remains unclear. In this work, we characterized the time course of functional integration of adult-born GCs in middle-aged mice. We performed whole-cell recordings in developing GCs from Ascl1CreERT2;CAGfloxStopTom mice and found a late onset of functional excitatory synaptogenesis, which occurred at 4 weeks (vs. 2 weeks in young-adult mice). Overall mature excitability and maximal glutamatergic connectivity were achieved at 10 weeks. In contrast, large mossy fiber boutons (MFBs) in CA3 displayed mature morphological features including filopodial extensions at 4 weeks, suggesting that efferent connectivity develops faster than afference. Notably, new GCs from middle-aged mice exposed to enriched environment for 7 days showed an advanced degree of maturity at 3 weeks, revealed by the high frequency of excitatory postsynaptic responses, complex dendritic trees, and large size of MFBs with filopodial extensions. These findings demonstrate that adult-born neurons act as sensors that transduce behavioral stimuli into major network remodeling in the aging brain.
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Affiliation(s)
| | | | | | - Alejandro F. Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
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11
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Trinchero MF, Buttner KA, Sulkes Cuevas JN, Temprana SG, Fontanet PA, Monzón-Salinas MC, Ledda F, Paratcha G, Schinder AF. High Plasticity of New Granule Cells in the Aging Hippocampus. Cell Rep 2018; 21:1129-1139. [PMID: 29091753 DOI: 10.1016/j.celrep.2017.09.064] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/23/2017] [Accepted: 09/19/2017] [Indexed: 12/16/2022] Open
Abstract
During aging, the brain undergoes changes that impair cognitive capacity and circuit plasticity, including a marked decrease in production of adult-born hippocampal neurons. It is unclear whether development and integration of those new neurons are also affected by age. Here, we show that adult-born granule cells (GCs) in aging mice are scarce and exhibit slow development, but they display a remarkable potential for structural plasticity. Retrovirally labeled 3-week-old GCs in middle-aged mice were small, underdeveloped, and disconnected. Neuronal development and integration were accelerated by voluntary exercise or environmental enrichment. Similar effects were observed via knockdown of Lrig1, an endogenous negative modulator of neurotrophin receptors. Consistently, blocking neurotrophin signaling by Lrig1 overexpression abolished the positive effects of exercise. These results demonstrate an unparalleled degree of plasticity in the aging brain mediated by neurotrophins, whereby new GCs remain immature until becoming rapidly recruited to the network by activity.
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Affiliation(s)
- Mariela F Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Karina A Buttner
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Jessica N Sulkes Cuevas
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Silvio G Temprana
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Paula A Fontanet
- División de Neurociencia Celular y Molecular, Instituto de Biología Celular y Neurociencias (IBCN-CONICET-UBA), Facultad de Medicina, Paraguay 2155, Buenos Aires C1121ABG, Argentina
| | - M Cristina Monzón-Salinas
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Fernanda Ledda
- División de Neurociencia Celular y Molecular, Instituto de Biología Celular y Neurociencias (IBCN-CONICET-UBA), Facultad de Medicina, Paraguay 2155, Buenos Aires C1121ABG, Argentina
| | - Gustavo Paratcha
- División de Neurociencia Celular y Molecular, Instituto de Biología Celular y Neurociencias (IBCN-CONICET-UBA), Facultad de Medicina, Paraguay 2155, Buenos Aires C1121ABG, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
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12
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Schinder AF, Lanuza GM. Whispering neurons fuel cortical highways. Science 2018; 360:265-266. [PMID: 29674579 DOI: 10.1126/science.aat4587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Consejo Nacional de Investigaciones Científicas y, Técnicas (CONICET), Avenida Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
| | - Guillermo M Lanuza
- Laboratorio de Genética del Desarrollo Neural, Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, CONICET, Avenida Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
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13
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Kempermann G, Gage FH, Aigner L, Song H, Curtis MA, Thuret S, Kuhn HG, Jessberger S, Frankland PW, Cameron HA, Gould E, Hen R, Abrous DN, Toni N, Schinder AF, Zhao X, Lucassen PJ, Frisén J. Human Adult Neurogenesis: Evidence and Remaining Questions. Cell Stem Cell 2018; 23:25-30. [PMID: 29681514 DOI: 10.1016/j.stem.2018.04.004] [Citation(s) in RCA: 490] [Impact Index Per Article: 81.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Renewed discussion about whether or not adult neurogenesis exists in the human hippocampus, and the nature and strength of the supporting evidence, has been reignited by two prominently published reports with opposite conclusions. Here, we summarize the state of the field and argue that there is currently no reason to abandon the idea that adult-generated neurons make important functional contributions to neural plasticity and cognition across the human lifespan.
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Affiliation(s)
- Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE) Dresden and CRTD (Center for Regenerative Therapies Dresden), Technische Universität Dresden, Dresden, Germany.
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, CA, USA.
| | - Ludwig Aigner
- Institute of Molecular Regenerative Medicine, Spinal Cord Injury and Tissue Regeneration Center Salzburg, Paracelsus Medical University, Salzburg, Austria
| | - Hongjun Song
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, USA
| | - Maurice A Curtis
- Department of Anatomy and Medical Imaging and Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Sandrine Thuret
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Department of Basic and Clinical Neuroscience, London, UK
| | - H Georg Kuhn
- University of Gothenburg, Institute for Neuroscience and Physiology, Section for Clinical Neuroscience, Gothenburg, Sweden; Charité - Universitätsmedizin Berlin, Neurocure Cluster of Excellence, Berlin, Germany
| | | | - Paul W Frankland
- Program in Neuroscience and Mental Health, Hospital for Sick Children, Toronto, ON M5GOA4, Canada
| | - Heather A Cameron
- Section on Neuroplasticity, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Elizabeth Gould
- Princeton Neuroscience Institute, Princeton University, Princeton, NJ, USA
| | - Rene Hen
- Departments of Neuroscience and Psychiatry, Columbia University, New York, NY, USA
| | - D Nora Abrous
- Neurocentre Magendie, INSERM U1215, Bordeaux, France
| | - Nicolas Toni
- Lausanne University Hospital, Department of Psychiatry, Center for Psychiatric Neurosciences, Lausanne, Switzerland
| | | | - Xinyu Zhao
- Waisman Center and Department of Neuroscience, University of Wisconsin-Madison School of Medicine and Public Health, Madison, WI, USA
| | - Paul J Lucassen
- Brain Plasticity group, Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, the Netherlands
| | - Jonas Frisén
- Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden.
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14
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Pozo Devoto VM, Dimopoulos N, Alloatti M, Pardi MB, Saez TM, Otero MG, Cromberg LE, Marín-Burgin A, Scassa ME, Stokin GB, Schinder AF, Sevlever G, Falzone TL. αSynuclein control of mitochondrial homeostasis in human-derived neurons is disrupted by mutations associated with Parkinson's disease. Sci Rep 2017; 7:5042. [PMID: 28698628 PMCID: PMC5506004 DOI: 10.1038/s41598-017-05334-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 06/07/2017] [Indexed: 01/10/2023] Open
Abstract
The etiology of Parkinson’s disease (PD) converges on a common pathogenic pathway of mitochondrial defects in which α-Synuclein (αSyn) is thought to play a role. However, the mechanisms by which αSyn and its disease-associated allelic variants cause mitochondrial dysfunction remain unknown. Here, we analyzed mitochondrial axonal transport and morphology in human-derived neurons overexpressing wild-type (WT) αSyn or the mutated variants A30P or A53T, which are known to have differential lipid affinities. A53T αSyn was enriched in mitochondrial fractions, inducing significant mitochondrial transport defects and fragmentation, while milder defects were elicited by WT and A30P. We found that αSyn-mediated mitochondrial fragmentation was linked to expression levels in WT and A53T variants. Targeted delivery of WT and A53T αSyn to the outer mitochondrial membrane further increased fragmentation, whereas A30P did not. Genomic editing to disrupt the N-terminal domain of αSyn, which is important for membrane association, resulted in mitochondrial elongation without changes in fusion-fission protein levels, suggesting that αSyn plays a direct physiological role in mitochondrial size maintenance. Thus, we demonstrate that the association of αSyn with the mitochondria, which is modulated by protein mutation and dosage, influences mitochondrial transport and morphology, highlighting its relevance in a common pathway impaired in PD.
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Affiliation(s)
- Victorio Martin Pozo Devoto
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina.,International Clinical Research Center (ICRC), St. Anne's University Hospital, CZ-65691, Brno, Czech Republic
| | - Nicolas Dimopoulos
- Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI), Montañeses 2325, Buenos Aires, C1428AQK, Argentina
| | - Matías Alloatti
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina
| | - María Belén Pardi
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) -CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Trinidad M Saez
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina.,Instituto de Biología y Medicina Experimental, IBYME (CONICET). Vuelta de obligado 2490, Buenos Aires, CP, 1428, Argentina
| | - María Gabriela Otero
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina
| | - Lucas Eneas Cromberg
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina
| | - Antonia Marín-Burgin
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) -CONICET - Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Maria Elida Scassa
- Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI), Montañeses 2325, Buenos Aires, C1428AQK, Argentina
| | - Gorazd B Stokin
- International Clinical Research Center (ICRC), St. Anne's University Hospital, CZ-65691, Brno, Czech Republic
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires, CP C1405BWE, Argentina
| | - Gustavo Sevlever
- Fundación para la Lucha contra las Enfermedades Neurológicas de la Infancia (FLENI), Montañeses 2325, Buenos Aires, C1428AQK, Argentina
| | - Tomás Luis Falzone
- Instituto de Biología Celular y Neurociencias, IBCN (UBA-CONICET), Facultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, Buenos Aires, CP1121, Argentina. .,Instituto de Biología y Medicina Experimental, IBYME (CONICET). Vuelta de obligado 2490, Buenos Aires, CP, 1428, Argentina.
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15
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Beckervordersandforth R, Ebert B, Schäffner I, Moss J, Fiebig C, Shin J, Moore DL, Ghosh L, Trinchero MF, Stockburger C, Friedland K, Steib K, von Wittgenstein J, Keiner S, Redecker C, Hölter SM, Xiang W, Wurst W, Jagasia R, Schinder AF, Ming GL, Toni N, Jessberger S, Song H, Lie DC. Role of Mitochondrial Metabolism in the Control of Early Lineage Progression and Aging Phenotypes in Adult Hippocampal Neurogenesis. Neuron 2017; 93:1518. [PMID: 28334613 DOI: 10.1016/j.neuron.2017.03.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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16
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Beckervordersandforth R, Ebert B, Schäffner I, Moss J, Fiebig C, Shin J, Moore DL, Ghosh L, Trinchero MF, Stockburger C, Friedland K, Steib K, von Wittgenstein J, Keiner S, Redecker C, Hölter SM, Xiang W, Wurst W, Jagasia R, Schinder AF, Ming GL, Toni N, Jessberger S, Song H, Lie DC. Role of Mitochondrial Metabolism in the Control of Early Lineage Progression and Aging Phenotypes in Adult Hippocampal Neurogenesis. Neuron 2017; 93:560-573.e6. [PMID: 28111078 DOI: 10.1016/j.neuron.2016.12.017] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 08/06/2016] [Accepted: 11/23/2016] [Indexed: 12/20/2022]
Abstract
Precise regulation of cellular metabolism is hypothesized to constitute a vital component of the developmental sequence underlying the life-long generation of hippocampal neurons from quiescent neural stem cells (NSCs). The identity of stage-specific metabolic programs and their impact on adult neurogenesis are largely unknown. We show that the adult hippocampal neurogenic lineage is critically dependent on the mitochondrial electron transport chain and oxidative phosphorylation machinery at the stage of the fast proliferating intermediate progenitor cell. Perturbation of mitochondrial complex function by ablation of the mitochondrial transcription factor A (Tfam) reproduces multiple hallmarks of aging in hippocampal neurogenesis, whereas pharmacological enhancement of mitochondrial function ameliorates age-associated neurogenesis defects. Together with the finding of age-associated alterations in mitochondrial function and morphology in NSCs, these data link mitochondrial complex function to efficient lineage progression of adult NSCs and identify mitochondrial function as a potential target to ameliorate neurogenesis-defects in the aging hippocampus.
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Affiliation(s)
- Ruth Beckervordersandforth
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
| | - Birgit Ebert
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany; Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich-Neuherberg, Germany
| | - Iris Schäffner
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Jonathan Moss
- Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland
| | - Christian Fiebig
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Jaehoon Shin
- Institute for Cell Engineering, Department of Neurology, The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Darcie L Moore
- Brain Research Institute, Faculty of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - Laboni Ghosh
- Brain Research Institute, Faculty of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - Mariela F Trinchero
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA, CONICET), C1405BWE Buenos Aires, Argentina
| | - Carola Stockburger
- Molecular and Clinical Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Kristina Friedland
- Molecular and Clinical Pharmacy, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Kathrin Steib
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich-Neuherberg, Germany
| | - Julia von Wittgenstein
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Silke Keiner
- Hans Berger Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Christoph Redecker
- Hans Berger Department of Neurology, Jena University Hospital, 07747 Jena, Germany
| | - Sabine M Hölter
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich-Neuherberg, Germany
| | - Wei Xiang
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich-Neuherberg, Germany
| | - Ravi Jagasia
- Institute of Developmental Genetics, Helmholtz Center Munich, German Research Center for Environmental Health, 85764 Munich-Neuherberg, Germany; F. Hoffmann-La Roche Ltd, CNS Discovery; Pharma Research and Early Development, 4070 Basel, Switzerland
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA, CONICET), C1405BWE Buenos Aires, Argentina
| | - Guo-Li Ming
- Institute for Cell Engineering, Department of Neurology, The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Nicolas Toni
- Department of Fundamental Neuroscience, University of Lausanne, 1005 Lausanne, Switzerland
| | - Sebastian Jessberger
- Brain Research Institute, Faculty of Medicine and Science, University of Zurich, 8057 Zurich, Switzerland
| | - Hongjun Song
- Institute for Cell Engineering, Department of Neurology, The Solomon Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - D Chichung Lie
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.
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17
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Sailor KA, Schinder AF, Lledo PM. Adult neurogenesis beyond the niche: its potential for driving brain plasticity. Curr Opin Neurobiol 2016; 42:111-117. [PMID: 28040643 DOI: 10.1016/j.conb.2016.12.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 11/30/2016] [Accepted: 12/05/2016] [Indexed: 12/14/2022]
Abstract
Adult neurogenesis emerges as a tremendous form of plasticity with the continuous addition and loss of neurons in the adult brain. It is unclear how preexisting adult circuits generated during development are capable of modifying existing connections to accommodate the thousands of new synapses formed and exchanged each day. Here we first make parallels with sensory deprivation studies and its ability to induce preexisting non-neurogenic adult circuits to undergo massive reorganization. We then review recent studies that show high structural and synaptic plasticity in circuits directly connected to adult-born neurons. Finally, we propose future directions in the field to decipher how host circuits can accommodate new neuron integration and to determine the impact of adult neurogenesis on global brain plasticity.
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Affiliation(s)
- Kurt A Sailor
- Laboratory for Perception and Memory, Pasteur Institute, F-75015 Paris, France; Centre National de la Recherche Scientifique (CNRS), Unité de Recherche Associée (UMR3571), F-75015 Paris, France
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Pierre-Marie Lledo
- Laboratory for Perception and Memory, Pasteur Institute, F-75015 Paris, France; Centre National de la Recherche Scientifique (CNRS), Unité de Recherche Associée (UMR3571), F-75015 Paris, France.
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18
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Alvarez DD, Giacomini D, Yang SM, Trinchero MF, Temprana SG, Büttner KA, Beltramone N, Schinder AF. A disynaptic feedback network activated by experience promotes the integration of new granule cells. Science 2016; 354:459-465. [PMID: 27789840 DOI: 10.1126/science.aaf2156] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 09/16/2016] [Indexed: 12/12/2022]
Abstract
Experience shapes the development and connectivity of adult-born granule cells (GCs) through mechanisms that are poorly understood. We examined the remodeling of dentate gyrus microcircuits in mice in an enriched environment (EE). Short exposure to EE during early development of new GCs accelerated their functional integration. This effect was mimicked by in vivo chemogenetic activation of a limited population of mature GCs. Slice recordings showed that mature GCs recruit parvalbumin γ-aminobutyric acid-releasing interneurons (PV-INs) that feed back onto developing GCs. Accordingly, chemogenetic stimulation of PV-INs or direct depolarization of developing GCs accelerated GC integration, whereas inactivation of PV-INs prevented the effects of EE. Our results reveal a mechanism for dynamic remodeling in which experience activates dentate networks that "prime" young GCs through a disynaptic feedback loop mediated by PV-INs.
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Affiliation(s)
- Diego D Alvarez
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Sung Min Yang
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Mariela F Trinchero
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Silvio G Temprana
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Karina A Büttner
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Natalia Beltramone
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
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19
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Lempel AA, Coll L, Schinder AF, Uchitel OD, Piriz J. Chronic pregabalin treatment decreases excitability of dentate gyrus and accelerates maturation of adult-born granule cells. J Neurochem 2016; 140:257-267. [PMID: 27419661 DOI: 10.1111/jnc.13740] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/12/2016] [Accepted: 07/05/2016] [Indexed: 11/29/2022]
Abstract
Pregabalin (PGB) is extensively prescribed to treat neurological and neuropsychiatrical conditions such as neuropathic pain, anxiety disorders, and epilepsy. Although PGB is known to bind selectively to the α2δ subunit of voltage-gated calcium channels, there is little understanding about how it exerts its therapeutic effects. In this article, we analyzed the effects of an in vivo chronic treatment with PGB over the physiology of dentate gyrus granule cells (DGGCs) using ex vivo electrophysiological and morphological analysis in adult mice. We found that PGB decreases neuronal excitability of DGGCs. In addition, PGB accelerates maturation of adult-born DGGCs, an effect that would modify dentate gyrus plasticity. Together, these findings suggest that PGB reduces activity in the dentate gyrus and modulates overall network plasticity, which might contribute to its therapeutic effects. Cover Image for this issue: doi: 10.1111/jnc.13783.
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Affiliation(s)
- Augusto Abel Lempel
- Instituto de Fisiología Biología Molecular y Neurociencias (IFIBYNE, UBA-CONICET), Buenos Aires, Argentina
| | - Lucia Coll
- Instituto de Fisiología Biología Molecular y Neurociencias (IFIBYNE, UBA-CONICET), Buenos Aires, Argentina
| | - Alejandro F Schinder
- Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires (IIBBA - CONICET), Buenos Aires, Argentina
| | - Osvaldo Daniel Uchitel
- Instituto de Fisiología Biología Molecular y Neurociencias (IFIBYNE, UBA-CONICET), Buenos Aires, Argentina
| | - Joaquin Piriz
- Instituto de Fisiología Biología Molecular y Neurociencias (IFIBYNE, UBA-CONICET), Buenos Aires, Argentina.,Instituto de Fisiología y Biofísica "Houssay" (IFIBIO "Houssay", UBA-CONICET), Buenos Aires, Argentina
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20
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Petracca YL, Sartoretti MM, Di Bella DJ, Marin-Burgin A, Carcagno AL, Schinder AF, Lanuza GM. The late and dual origin of cerebrospinal fluid-contacting neurons in the mouse spinal cord. Development 2016; 143:880-91. [PMID: 26839365 DOI: 10.1242/dev.129254] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/25/2016] [Indexed: 12/16/2022]
Abstract
Considerable progress has been made in understanding the mechanisms that control the production of specialized neuronal types. However, how the timing of differentiation contributes to neuronal diversity in the developing spinal cord is still a pending question. In this study, we show that cerebrospinal fluid-contacting neurons (CSF-cNs), an anatomically discrete cell type of the ependymal area, originate from surprisingly late neurogenic events in the ventral spinal cord. CSF-cNs are identified by the expression of the transcription factors Gata2 and Gata3, and the ionic channels Pkd2l1 and Pkd1l2. Contrasting with Gata2/3(+) V2b interneurons, differentiation of CSF-cNs is independent of Foxn4 and takes place during advanced developmental stages previously assumed to be exclusively gliogenic. CSF-cNs are produced from two distinct dorsoventral regions of the mouse spinal cord. Most CSF-cNs derive from progenitors circumscribed to the late-p2 and the oligodendrogenic (pOL) domains, whereas a second subset of CSF-cNs arises from cells bordering the floor plate. The development of these two subgroups of CSF-cNs is differentially controlled by Pax6, they adopt separate locations around the postnatal central canal and they display electrophysiological differences. Our results highlight that spatiotemporal mechanisms are instrumental in creating neural cell diversity in the ventral spinal cord to produce distinct classes of interneurons, motoneurons, CSF-cNs, glial cells and ependymal cells.
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Affiliation(s)
- Yanina L Petracca
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Maria Micaela Sartoretti
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Daniela J Di Bella
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Antonia Marin-Burgin
- Neuronal Plasticity Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Abel L Carcagno
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Alejandro F Schinder
- Neuronal Plasticity Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
| | - Guillermo M Lanuza
- Developmental Neurobiology Lab, Instituto Leloir and Consejo Nacional de Investigaciones Científicas y Técnicas (IIBBA-CONICET), Avenida Patricias Argentinas 435, Buenos Aires 1405, Argentina
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21
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Abstract
The adult hippocampus generates functional dentate granule cells (GCs) that release glutamate onto target cells in the hilus and cornus ammonis (CA)3 region, and receive glutamatergic and γ-aminobutyric acid (GABA)ergic inputs that tightly control their spiking activity. The slow and sequential development of their excitatory and inhibitory inputs makes them particularly relevant for information processing. Although they are still immature, new neurons are recruited by afferent activity and display increased excitability, enhanced activity-dependent plasticity of their input and output connections, and a high rate of synaptogenesis. Once fully mature, new GCs show all the hallmarks of neurons generated during development. In this review, we focus on how developing neurons remodel the adult dentate gyrus and discuss key aspects that illustrate the potential of neurogenesis as a mechanism for circuit plasticity and function.
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Affiliation(s)
- Nicolas Toni
- Department of Fundamental Neurosciences, University of Lausanne, CH-1005 Lausanne, Switzerland
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Pardi MB, Ogando MB, Schinder AF, Marin-Burgin A. Differential inhibition onto developing and mature granule cells generates high-frequency filters with variable gain. eLife 2015; 4:e08764. [PMID: 26163657 PMCID: PMC4521582 DOI: 10.7554/elife.08764] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 07/10/2015] [Indexed: 11/13/2022] Open
Abstract
Adult hippocampal neurogenesis provides the dentate gyrus with heterogeneous populations of granule cells (GC) originated at different times. The contribution of these cells to information encoding is under current investigation. Here, we show that incoming spike trains activate different populations of GC determined by the stimulation frequency and GC age. Immature GC respond to a wider range of stimulus frequencies, whereas mature GC are less responsive at high frequencies. This difference is dictated by feedforward inhibition, which restricts mature GC activation. Yet, the stronger inhibition of mature GC results in a higher temporal fidelity compared to that of immature GC. Thus, hippocampal inputs activate two populations of neurons with variable frequency filters: immature cells, with wide-range responses, that are reliable transmitters of the incoming frequency, and mature neurons, with narrow frequency response, that are precise at informing the beginning of the stimulus, but with a sparse activity.
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Affiliation(s)
- María Belén Pardi
- Instituto de Investigación en Biomedicina de Buenos Aires-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Mora Belén Ogando
- Instituto de Investigación en Biomedicina de Buenos Aires-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Buenos Aires, Argentina
| | - Antonia Marin-Burgin
- Instituto de Investigación en Biomedicina de Buenos Aires-CONICET-Partner Institute of the Max Planck Society, Buenos Aires, Argentina
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23
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Kropff E, Yang SM, Schinder AF. Dynamic role of adult-born dentate granule cells in memory processing. Curr Opin Neurobiol 2015; 35:21-6. [PMID: 26100379 DOI: 10.1016/j.conb.2015.06.002] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 06/02/2015] [Accepted: 06/03/2015] [Indexed: 12/20/2022]
Abstract
Throughout the adult life of all mammals including humans, new neurons are incorporated to the dentate gyrus of the hippocampus. During a critical window that lasts about two weeks, adult-born immature neurons are more excitable and plastic than mature ones, and they respond to a wider range of inputs. In apparent contradiction, new neurons have been shown to be crucial to solve behavioral tasks that involve the discrimination of very similar situations, which would instead require high input specificity. We propose that immature neurons are initially unspecific because their task is to identify novel elements inside a high dimensional input space. With maturation, they would specialize to represent details of these novel inputs, favoring discrimination.
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Affiliation(s)
- Emilio Kropff
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Sung M Yang
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA - CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina.
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24
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Trinchero MF, Koehl M, Bechakra M, Delage P, Charrier V, Grosjean N, Ladeveze E, Schinder AF, Abrous DN. Effects of spaced learning in the water maze on development of dentate granule cells generated in adult mice. Hippocampus 2015; 25:1314-26. [DOI: 10.1002/hipo.22438] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 02/24/2015] [Accepted: 02/24/2015] [Indexed: 12/29/2022]
Affiliation(s)
- Mariela F. Trinchero
- Laboratory of Neuronal Plasticity; Leloir Institute, Consejo Nacional De Investigaciones Científicas Y Técnicas; Buenos Aires Argentina
| | - Muriel Koehl
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Malik Bechakra
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Pauline Delage
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Vanessa Charrier
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Noelle Grosjean
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Elodie Ladeveze
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
| | - Alejandro F. Schinder
- Laboratory of Neuronal Plasticity; Leloir Institute, Consejo Nacional De Investigaciones Científicas Y Técnicas; Buenos Aires Argentina
| | - D. Nora Abrous
- Inserm U862; Bordeaux France
- Université De Bordeaux; Bordeaux France
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25
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Temprana SG, Mongiat LA, Yang SM, Trinchero MF, Alvarez DD, Kropff E, Giacomini D, Beltramone N, Lanuza GM, Schinder AF. Delayed coupling to feedback inhibition during a critical period for the integration of adult-born granule cells. Neuron 2014; 85:116-130. [PMID: 25533485 DOI: 10.1016/j.neuron.2014.11.023] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2014] [Indexed: 10/24/2022]
Abstract
Developing granule cells (GCs) of the adult dentate gyrus undergo a critical period of enhanced activity and synaptic plasticity before becoming mature. The impact of developing GCs on the activity of preexisting dentate circuits remains unknown. Here we combine optogenetics, acute slice electrophysiology, and in vivo chemogenetics to activate GCs at different stages of maturation to study the recruitment of local target networks. We show that immature (4-week-old) GCs can efficiently drive distal CA3 targets but poorly activate proximal interneurons responsible for feedback inhibition (FBI). As new GCs transition toward maturity, they reliably recruit GABAergic feedback loops that restrict spiking of neighbor GCs, a mechanism that would promote sparse coding. Such inhibitory loop impinges only weakly in new cohorts of young GCs. A computational model reveals that the delayed coupling of new GCs to FBI could be crucial to achieve a fine-grain representation of novel inputs in the dentate gyrus.
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Affiliation(s)
- Silvio G Temprana
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Lucas A Mongiat
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Sung M Yang
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Mariela F Trinchero
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Diego D Alvarez
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Emilio Kropff
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Damiana Giacomini
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Natalia Beltramone
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Guillermo M Lanuza
- Laboratory of Developmental Neurobiology, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute-CONICET, Av. Patricias Argentinas 435, Buenos Aires, C1405BWE, Argentina.
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26
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Krzisch M, Temprana SG, Mongiat LA, Armida J, Schmutz V, Virtanen MA, Kocher-Braissant J, Kraftsik R, Vutskits L, Conzelmann KK, Bergami M, Gage FH, Schinder AF, Toni N. Pre-existing astrocytes form functional perisynaptic processes on neurons generated in the adult hippocampus. Brain Struct Funct 2014; 220:2027-42. [PMID: 24748560 PMCID: PMC4481333 DOI: 10.1007/s00429-014-0768-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 03/31/2014] [Indexed: 11/26/2022]
Abstract
The adult dentate gyrus produces new neurons that morphologically and functionally integrate into the hippocampal network. In the adult brain, most excitatory synapses are ensheathed by astrocytic perisynaptic processes that regulate synaptic structure and function. However, these processes are formed during embryonic or early postnatal development and it is unknown whether astrocytes can also ensheathe synapses of neurons born during adulthood and, if so, whether they play a role in their synaptic transmission. Here, we used a combination of serial-section immuno-electron microscopy, confocal microscopy, and electrophysiology to examine the formation of perisynaptic processes on adult-born neurons. We found that the afferent and efferent synapses of newborn neurons are ensheathed by astrocytic processes, irrespective of the age of the neurons or the size of their synapses. The quantification of gliogenesis and the distribution of astrocytic processes on synapses formed by adult-born neurons suggest that the majority of these processes are recruited from pre-existing astrocytes. Furthermore, the inhibition of astrocytic glutamate re-uptake significantly reduced postsynaptic currents and increased paired-pulse facilitation in adult-born neurons, suggesting that perisynaptic processes modulate synaptic transmission on these cells. Finally, some processes were found intercalated between newly formed dendritic spines and potential presynaptic partners, suggesting that they may also play a structural role in the connectivity of new spines. Together, these results indicate that pre-existing astrocytes remodel their processes to ensheathe synapses of adult-born neurons and participate to the functional and structural integration of these cells into the hippocampal network.
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Affiliation(s)
- Marine Krzisch
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
| | - Silvio G. Temprana
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires, Argentina
| | - Lucas A. Mongiat
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires, Argentina
| | - Jan Armida
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
| | - Valentin Schmutz
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
| | - Mari A. Virtanen
- Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland
| | - Jacqueline Kocher-Braissant
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
| | - Rudolf Kraftsik
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
| | - Laszlo Vutskits
- Department of Fundamental Neurosciences, University of Geneva, Geneva, Switzerland
- Department of Anesthesiology, Pharmacology and Intensive Care, University Hospital of Geneva, Geneva, Switzerland
| | - Karl-Klaus Conzelmann
- Max von Pettenkofer Institute and Gene Center, Ludwig-Maximilians University Munich, Munich, Germany
| | - Matteo Bergami
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD) and University Hospital of Cologne, Cologne, Germany
| | - Fred H. Gage
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA USA
| | - Alejandro F. Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires, Argentina
| | - Nicolas Toni
- Department of Fundamental Neurosciences, University of Lausanne, 9 rue du Bugnon, 1005 Lausanne, Switzerland
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Morgenstern NA, Giacomini D, Lombardi G, Castaño EM, Schinder AF. Delayed dendritic development in newly generated dentate granule cells by cell-autonomous expression of the amyloid precursor protein. Mol Cell Neurosci 2013; 56:298-306. [PMID: 23851186 DOI: 10.1016/j.mcn.2013.07.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 05/15/2013] [Accepted: 07/03/2013] [Indexed: 11/30/2022] Open
Abstract
Neuronal connectivity and synaptic remodeling are fundamental substrates for higher brain functions. Understanding their dynamics in the mammalian allocortex emerges as a critical step to tackle the cellular basis of cognitive decline that occurs during normal aging and in neurodegenerative disorders. In this work we have designed a novel approach to assess alterations in the dynamics of functional and structural connectivity elicited by chronic cell-autonomous overexpression of the human amyloid precursor protein (hAPP). We have taken advantage of the fact that the hippocampus continuously generates new dentate granule cells (GCs) to probe morphofunctional development of GCs expressing different variants of hAPP in a healthy background. hAPP was expressed together with a fluorescent reporter in neural progenitor cells of the dentate gyrus of juvenile mice by retroviral delivery. Neuronal progeny was analyzed several days post infection (dpi). Amyloidogenic cleavage products of hAPP such as the β-C terminal fragment (β-CTF) induced a substantial reduction in glutamatergic connectivity at 21 dpi, at which time new GCs undergo active growth and synaptogenesis. Interestingly, this effect was transient, since the strength of glutamatergic inputs was normal by 35 dpi. This delay in glutamatergic synaptogenesis was paralleled by a decrease in dendritic length with no changes in spine density, consistent with a protracted dendritic development without alterations in synapse formation. Finally, similar defects in newborn GC development were observed by overexpression of α-CTF, a non-amyloidogenic cleavage product of hAPP. These results indicate that hAPP can elicit protracted dendritic development independently of the amyloidogenic processing pathway.
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Affiliation(s)
- Nicolás A Morgenstern
- Laboratory of Neuronal Plasticity Leloir Institute (IIBBA-CONICET) Buenos Aires (1405), Argentina
| | - Damiana Giacomini
- Laboratory of Neuronal Plasticity Leloir Institute (IIBBA-CONICET) Buenos Aires (1405), Argentina
| | - Gabriela Lombardi
- Laboratory of Neuronal Plasticity Leloir Institute (IIBBA-CONICET) Buenos Aires (1405), Argentina
| | - Eduardo M Castaño
- Laboratory of Amyloidosis and Neurodegeneration Leloir Institute (IIBBA-CONICET) Buenos Aires (1405), Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity Leloir Institute (IIBBA-CONICET) Buenos Aires (1405), Argentina
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28
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Marín-Burgin A, Schinder AF. Requirement of adult-born neurons for hippocampus-dependent learning. Behav Brain Res 2012; 227:391-9. [DOI: 10.1016/j.bbr.2011.07.001] [Citation(s) in RCA: 139] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Revised: 06/29/2011] [Accepted: 07/01/2011] [Indexed: 02/07/2023]
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Marín-Burgin A, Mongiat LA, Pardi MB, Schinder AF. Unique processing during a period of high excitation/inhibition balance in adult-born neurons. Science 2012; 335:1238-42. [PMID: 22282476 DOI: 10.1126/science.1214956] [Citation(s) in RCA: 279] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The adult dentate gyrus generates new granule cells (GCs) that develop over several weeks and integrate into the preexisting network. Although adult hippocampal neurogenesis has been implicated in learning and memory, the specific role of new GCs remains unclear. We examined whether immature adult-born neurons contribute to information encoding. By combining calcium imaging and electrophysiology in acute slices, we found that weak afferent activity recruits few mature GCs while activating a substantial proportion of the immature neurons. These different activation thresholds are dictated by an enhanced excitation/inhibition balance transiently expressed in immature GCs. Immature GCs exhibit low input specificity that switches with time toward a highly specific responsiveness. Therefore, activity patterns entering the dentate gyrus can undergo differential decoding by a heterogeneous population of GCs originated at different times.
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Affiliation(s)
- Antonia Marín-Burgin
- Laboratorio de Plasticidad Neuronal, Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Avenida Patricias Argentinas 435, 1405 Buenos Aires, Argentina
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30
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Abstract
The granule cell layer (GCL) of the dentate gyrus contains neurons generated during embryonic, early postnatal and adult life. During adulthood there is a continuous production of neuronal cohorts that develop and functionally integrate in the preexisting circuits. This morphogenic process generates a stratified GCL, with the outermost layers containing dentate granule cells (DGCs) generated during perinatal life, and the innermost layers containing adult-born DGCs. In this review we analyse the functional profile of the different neuronal populations of the GCL, with an emphasis on adult-born neurons as they develop, mature and integrate in the dentate gyrus network. We focus on the contribution of adult-born neurons to activity-dependent synaptic modification in the dentate gyrus and, in turn, discuss how network activity modulates integration and survival of new neurons.
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Affiliation(s)
- Lucas A Mongiat
- Laboratory of Neuronal Plasticity, Leloir Institute - CONICET, Buenos Aires, Argentina
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31
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Mathews EA, Morgenstern NA, Piatti VC, Zhao C, Jessberger S, Schinder AF, Gage FH. A distinctive layering pattern of mouse dentate granule cells is generated by developmental and adult neurogenesis. J Comp Neurol 2011; 518:4479-90. [PMID: 20886617 DOI: 10.1002/cne.22489] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
New neurons are continuously added throughout life to the dentate gyrus of the mammalian hippocampus. During embryonic and early postnatal development, the dentate gyrus is formed in an outside-in layering pattern that may extend through adulthood. In this work, we sought to quantify systematically the relative position of dentate granule cells generated at different ages. We used 5'-bromo-2'-deoxyuridine (BrdU) and retroviral methodologies to birth date cells born in the embryonic, early postnatal, and adult hippocampus and assessed their final position in the adult mouse granule cell layer. We also quantified both developmental and adult-born cohorts of neural progenitor cells that contribute to the pool of adult progenitor cells. Our data confirm that the outside-in layering of the dentate gyrus continues through adulthood and that early-born cells constitute most of the adult dentate gyrus. We also found that substantial numbers of the dividing cells in the adult dentate gyrus were derived from early-dividing cells and retained BrdU, suggesting that a subpopulation of hippocampal progenitors divides infrequently from early development onward.
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Affiliation(s)
- Emily A Mathews
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA
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32
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Mathews EA, Morgenstern NA, Piatti VC, Zhao C, Jessberger S, Schinder AF, Gage FH. A Distinctive layering pattern of mouse dentate granule cells is generated by developmental and adult neurogenesis. J Comp Neurol 2010. [DOI: 10.1002/cne.22514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Early stages of Alzheimer's disease (AD) affect hippocampal function. In this issue of Cell Stem Cell, Li et al. (2009) and Sun et al. (2009) propose abnormal GABA signaling as a trigger for impaired network plasticity in the AD hippocampus.
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Franco DL, Rezával C, Cáceres A, Schinder AF, Ceriani MF. ENA/VASP downregulation triggers cell death by impairing axonal maintenance in hippocampal neurons. Mol Cell Neurosci 2010; 44:154-64. [PMID: 20230896 DOI: 10.1016/j.mcn.2010.03.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 01/28/2010] [Accepted: 03/05/2010] [Indexed: 11/28/2022] Open
Abstract
Neurodegenerative diseases encompass a broad variety of motor and cognitive disorders that are accompanied by death of specific neuronal populations or brain regions. Cellular and molecular mechanisms underlying these complex disorders remain largely unknown. In a previous work we searched for novel Drosophila genes relevant for neurodegeneration and singled out enabled (ena), which encodes a protein involved in cytoskeleton remodeling. To extend our understanding on the mechanisms of ENA-triggered degeneration we now investigated the effect of silencing ena ortholog genes in mouse hippocampal neurons. We found that ENA/VASP downregulation led to neurite retraction and concomitant neuronal cell death through an apoptotic pathway. Remarkably, this retraction initially affected the axonal structure, showing no effect on dendrites. Reduction in ENA/VASP levels blocked the neuritogenic effect of a specific RhoA kinase (ROCK) inhibitor, thus suggesting that these proteins could participate in the Rho-signaling pathway. Altogether these observations demonstrate that ENA/VASP proteins are implicated in the establishment and maintenance of the axonal structure and that a change on their expression levels triggers neuronal degeneration.
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Affiliation(s)
- D Lorena Franco
- Laboratorio de Genética del Comportamiento, Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas-Buenos Aires (IIB-BA, CONICET), Argentina
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35
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Abstract
The dentate gyrus of the hippocampus generates neurons throughout life, but adult neurogenesis exhibits a marked age-dependent decline. Although the decrease in the rate of neurogenesis has been extensively documented in the ageing hippocampus, the specific characteristics of dentate granule cells born in such a continuously changing environment have received little attention. We have used retroviral labelling of neural progenitor cells of the adult mouse dentate gyrus to study morphological properties of neurons born at different ages. Dendritic spine density was measured to estimate glutamatergic afferent connectivity. Fully mature neurons born at the age of 2 months display approximately 2.3 spines microm(-1) and maintain their overall morphology and spine density in 1-year-old mice. Surprisingly, granule cells born in 10-month-old mice, at which time the rate of neurogenesis has decreased by approximately 40-fold, reach a density of dendritic spines similar to that of neurons born in young adulthood. Therefore, in spite of the sharp decline in cell proliferation, differentiation and overall neuronal number, the ageing hippocampus presents a suitable environment for new surviving neurons to reach a high level of complexity, comparable to that of all other dentate granule cells.
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Affiliation(s)
- Nicolás A Morgenstern
- Laboratory of Neuronal Plasticity, Leloir Institute - CONICET, Avenida Patricias Argentinas 435, (1405) Buenos Aires, Argentina
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Laplagne DA, Kamienkowski JE, Espósito MS, Piatti VC, Zhao C, Gage FH, Schinder AF. Similar GABAergic inputs in dentate granule cells born during embryonic and adult neurogenesis. Eur J Neurosci 2007; 25:2973-81. [PMID: 17509085 DOI: 10.1111/j.1460-9568.2007.05549.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Neurogenesis in the dentate gyrus of the hippocampus follows a unique temporal pattern that begins during embryonic development, peaks during the early postnatal stages and persists through adult life. We have recently shown that dentate granule cells born in early postnatal and adult mice acquire a remarkably similar afferent connectivity and firing behavior, suggesting that they constitute a homogeneous functional population [Laplagne et al. (2006)PLoS Biol., 4, e409]. Here we extend our previous study by comparing mature neurons born in the embryonic and adult hippocampus, with a focus on intrinsic membrane properties and gamma-aminobutyric acid (GABA)ergic synaptic inputs. For this purpose, dividing neuroblasts of the ventricular wall were retrovirally labeled with green fluorescent protein at embryonic day 15 (E15), and progenitor cells of the subgranular zone were labeled with red fluorescent protein in the same mice at postnatal day 42 (P42, adulthood). Electrophysiological properties of mature neurons born at either stage were then compared in the same brain slices. Evoked and spontaneous GABAergic postsynaptic responses of perisomatic and dendritic origin displayed similar characteristics in both neuronal populations. Miniature GABAergic inputs also showed similar functional properties and pharmacological profile. A comparative analysis of the present data with our previous observations rendered no significant differences among GABAergic inputs recorded from neurons born in the embryonic, early postnatal and adult mice. Yet, embryo-born neurons showed a reduced membrane excitability, suggesting a lower engagement in network activity. Our results demonstrate that granule cells of different age, location and degree of excitability receive GABAergic inputs of equivalent functional characteristics.
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Affiliation(s)
- Diego A Laplagne
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir (1405) Buenos Aires, Argentina
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37
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Laplagne DA, Espósito MS, Piatti VC, Morgenstern NA, Zhao C, van Praag H, Gage FH, Schinder AF. Functional convergence of neurons generated in the developing and adult hippocampus. PLoS Biol 2007; 4:e409. [PMID: 17121455 PMCID: PMC1637132 DOI: 10.1371/journal.pbio.0040409] [Citation(s) in RCA: 269] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2006] [Accepted: 09/22/2006] [Indexed: 11/18/2022] Open
Abstract
The dentate gyrus of the hippocampus contains neural progenitor cells (NPCs) that generate neurons throughout life. Developing neurons of the adult hippocampus have been described in depth. However, little is known about their functional properties as they become fully mature dentate granule cells (DGCs). To compare mature DGCs generated during development and adulthood, NPCs were labeled at both time points using retroviruses expressing different fluorescent proteins. Sequential electrophysiological recordings from neighboring neurons of different ages were carried out to quantitatively study their major synaptic inputs: excitatory projections from the entorhinal cortex and inhibitory afferents from local interneurons. Our results show that DGCs generated in the developing and adult hippocampus display a remarkably similar afferent connectivity with regard to both glutamate and GABA, the major neurotransmitters. We also demonstrate that adult-born neurons can fire action potentials in response to an excitatory drive, exhibiting a firing behavior comparable to that of neurons generated during development. We propose that neurons born in the developing and adult hippocampus constitute a functionally homogeneous neuronal population. These observations are critical to understanding the role of adult neurogenesis in hippocampal function. Adult neurogenesis in the hippocampus generates neurons with striking functional similarity to neurons born during development, indicating that adult-born neurons incorporate normally into hippocampal circuits.
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Affiliation(s)
| | | | | | | | - Chunmei Zhao
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Henriette van Praag
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, United States of America
| | - Alejandro F Schinder
- Fundación Instituto Leloir, Buenos Aires, Argentina
- * To whom correspondence should be addressed. E-mail:
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38
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Abstract
The granule cell layer (GCL) of the adult dentate gyrus (DG) is a heterogeneous structure formed by neurons of different ages because a significant proportion of neurons continues to be generated throughout life. The subgranular zone of the DG contains neural progenitor cells (NPCs) that divide, differentiate, and migrate to produce functional dentate granule cells (DGCs) that become incorporated into the existing hippocampal circuitry. New available tools to identify adult-born neurons in live and fixed brain sections have allowed the transition from NPC to functional neuron to be characterized in great detail. Maturation of the neuronal phenotype includes changes in membrane excitability and morphology as well as the establishment of appropriate connectivity within the existing circuits, a process that lasts several weeks. The events leading to neuronal maturation share many of the features of the developing brain, and electrical activity is emerging as a key modulator of neuronal development in the adult DG. The underlying mechanisms are now beginning to be understood.
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Espósito MS, Piatti VC, Laplagne DA, Morgenstern NA, Ferrari CC, Pitossi FJ, Schinder AF. Neuronal differentiation in the adult hippocampus recapitulates embryonic development. J Neurosci 2006; 25:10074-86. [PMID: 16267214 PMCID: PMC6725804 DOI: 10.1523/jneurosci.3114-05.2005] [Citation(s) in RCA: 503] [Impact Index Per Article: 27.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
In the adult hippocampus and olfactory bulb, neural progenitor cells generate neurons that functionally integrate into the existing circuits. To understand how neuronal differentiation occurs in the adult hippocampus, we labeled dividing progenitor cells with a retrovirus expressing green fluorescent protein and studied the morphological and functional properties of their neuronal progeny over the following weeks. During the first week neurons had an irregular shape and immature spikes and were synaptically silent. Slow GABAergic synaptic inputs first appeared during the second week, when neurons exhibited spineless dendrites and migrated into the granule cell layer. In contrast, glutamatergic afferents were detected by the fourth week in neurons displaying mature excitability and morphology. Interestingly, fast GABAergic responses were the latest to appear. It is striking that neuronal maturation in the adult hippocampus follows a precise sequence of connectivity (silent --> slow GABA --> glutamate --> fast GABA) that resembles hippocampal development. We conclude that, unlike what is observed in the olfactory bulb, the hippocampus maintains the same developmental rules for neuronal integration through adulthood.
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Song H, Kempermann G, Overstreet Wadiche L, Zhao C, Schinder AF, Bischofberger J. New neurons in the adult mammalian brain: synaptogenesis and functional integration. J Neurosci 2006; 25:10366-8. [PMID: 16280573 PMCID: PMC6725835 DOI: 10.1523/jneurosci.3452-05.2005] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Hongjun Song
- Institute for Cell Engineering, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
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Abstract
The functional relevance of adult hippocampal neurogenesis has long been a matter of intense experimentation and debate, but the precise role of new neurons has not been sufficiently elaborated. Here we propose a hypothesis in which specific features of newly generated neurons contribute to hippocampal plasticity and function and discuss the most recent and relevant findings in the context of the proposed hypothesis.
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Affiliation(s)
- Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute Foundation, 1405 Buenos Aires, Argentina.
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Abstract
There is extensive evidence indicating that new neurons are generated in the dentate gyrus of the adult mammalian hippocampus, a region of the brain that is important for learning and memory. However, it is not known whether these new neurons become functional, as the methods used to study adult neurogenesis are limited to fixed tissue. We use here a retroviral vector expressing green fluorescent protein that only labels dividing cells, and that can be visualized in live hippocampal slices. We report that newly generated cells in the adult mouse hippocampus have neuronal morphology and can display passive membrane properties, action potentials and functional synaptic inputs similar to those found in mature dentate granule cells. Our findings demonstrate that newly generated cells mature into functional neurons in the adult mammalian brain.
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Affiliation(s)
- Henriette van Praag
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California 92037, USA.
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Ganguly K, Schinder AF, Wong ST, Poo M. GABA itself promotes the developmental switch of neuronal GABAergic responses from excitation to inhibition. Cell 2001. [PMID: 11371348 DOI: 10.1016/s0092] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
GABA is the main inhibitory neurotransmitter in the adult brain. Early in development, however, GABAergic synaptic transmission is excitatory and can exert widespread trophic effects. During the postnatal period, GABAergic responses undergo a switch from being excitatory to inhibitory. Here, we show that the switch is delayed by chronic blockade of GABA(A) receptors, and accelerated by increased GABA(A) receptor activation. In contrast, blockade of glutamatergic transmission or action potentials has no effect. Furthermore, GABAergic activity modulated the mRNA levels of KCC2, a K(+)-Cl(-) cotransporter whose expression correlates with the switch. Finally, we report that GABA can alter the properties of depolarization-induced Ca(2+) influx. Thus, GABA acts as a self-limiting trophic factor during neural development.
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Affiliation(s)
- K Ganguly
- Program in Neuroscience, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
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Abstract
GABA is the main inhibitory neurotransmitter in the adult brain. Early in development, however, GABAergic synaptic transmission is excitatory and can exert widespread trophic effects. During the postnatal period, GABAergic responses undergo a switch from being excitatory to inhibitory. Here, we show that the switch is delayed by chronic blockade of GABA(A) receptors, and accelerated by increased GABA(A) receptor activation. In contrast, blockade of glutamatergic transmission or action potentials has no effect. Furthermore, GABAergic activity modulated the mRNA levels of KCC2, a K(+)-Cl(-) cotransporter whose expression correlates with the switch. Finally, we report that GABA can alter the properties of depolarization-induced Ca(2+) influx. Thus, GABA acts as a self-limiting trophic factor during neural development.
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Affiliation(s)
- K Ganguly
- Program in Neuroscience, Division of Biology, University of California, San Diego, La Jolla, CA 92093, USA
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45
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Abstract
The neurotrophin hypothesis proposes that neurotrophins participate in activity-induced modification of synaptic transmission. Increasingly, evidence indicates that the synthesis, secretion and actions of neurotrophins on synaptic transmission are regulated by electrical activity and that neurotrophins themselves can acutely modify synaptic efficacy. Neurotrophins appear to exert either a permissive or instructive role on activity-dependent synaptic potentiation and depression, which depends on the particular synaptic connections and developmental stages. The characteristics of synaptic changes that are induced by neurotrophins suggest that this family of proteins is crucial for providing a molecular background in which activity-dependent plasticity can occur at selective synaptic sites within the neural network.
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Affiliation(s)
- A F Schinder
- Dept of Biology, University of California at San Diego, La Jolla, CA 92093-0357, USA
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46
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Abstract
The role of the target cell in neurotrophin-induced modifications of glutamatergic synaptic transmission was examined in cultured hippocampal neurons. Brain-derived neurotrophic factor (BDNF) induced rapid and persistent potentiation of evoked glutamate release when the postsynaptic neuron was glutamatergic, or excitatory (E-->E), but not when it was GABAergic, or inhibitory (E-->1). This target-specific action of BDNF was also found at divergent outputs of a single presynaptic neuron innervating both glutamatergic and GABAergic neurons, suggesting that individual terminals can be independently modified. Surprisingly, BDNF increased the frequency of miniature postsynaptic currents at both E-->E and E-->I, although it had no effect on evoked currents at E-->I. Finally, potentiation by neurotrophin-3 (NT-3) was also target specific. The selective effect at E-->E suggests that retrograde signaling by the postsynaptic target cell endows a localized presynaptic action of neurotrophins.
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Affiliation(s)
- A F Schinder
- Department of Biology, University of California, San Diego, La Jolla 92093, USA
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Berninger B, Schinder AF, Poo MM. Synaptic Reliability Correlates with Reduced Susceptibility to Synaptic Potentiation by Brain-Derived Neurotrophic Factor. Learn Mem 1999. [DOI: 10.1101/lm.6.3.232] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Recent studies have implicated brain-derived neurotrophic factor (BDNF) in use-dependent modification of hippocampal synapses. BDNF can rapidly potentiate synaptic transmission at glutamatergic synapses by enhancing transmitter release. Using simultaneous perforated patch recording from pairs and triplets of glutamatergic hippocampal neurons, we have examined how the initial state of the glutamatergic synapse determines its susceptibility to synaptic modification by BDNF. We found that the degree of synaptic potentiation by BDNF depends on the initial reliability and strength of the synapse: Relatively weak connections were strongly potentiated, whereas the effect was markedly reduced at stronger synapses. The degree of BDNF-induced potentiation strongly correlated with the initial coefficient of variation (CV) of the amplitude of excitatory postsynaptic currents (EPSCs) and inversely correlated with the initial paired–pulse facilitation, suggesting that synapses with lower release probability (Pr) are more susceptible to the action of BDNF. To determine whether saturation of Pr could have masked the potentiation effect of BDNF in the stronger synapses, we lowered the initial Pr either by reducing the extracellular Ca2+ concentration ([Ca2+]o) or by bath application of adenosine. Synapses that were initially strong remained unaffected by BDNF under these conditions of reduced Pr. Thus, the lack of BDNF effect on synaptic efficacy cannot simply be accounted for by saturation of Pr, but rather may be due to intrinsic changes associated with synaptic maturation that might covary with Pr. Finally, the dependence on initial synaptic strength was also found for divergent outputs of the same presynaptic neuron, suggesting that synaptic terminals with different degrees of responsiveness to BDNF can coexist within in the same neuron.
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Berninger B, Schinder AF, Poo MM. Synaptic reliability correlates with reduced susceptibility to synaptic potentiation by brain-derived neurotrophic factor. Learn Mem 1999; 6:232-42. [PMID: 10492005 PMCID: PMC311306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
Recent studies have implicated brain-derived neurotrophic factor (BDNF) in use-dependent modification of hippocampal synapses. BDNF can rapidly potentiate synaptic transmission at glutamatergic synapses by enhancing transmitter release. Using simultaneous perforated patch recording from pairs and triplets of glutamatergic hippocampal neurons, we have examined how the initial state of the glutamatergic synapse determines its susceptibility to synaptic modification by BDNF. We found that the degree of synaptic potentiation by BDNF depends on the initial reliability and strength of the synapse: Relatively weak connections were strongly potentiated, whereas the effect was markedly reduced at stronger synapses. The degree of BDNF-induced potentiation strongly correlated with the initial coefficient of variation (CV) of the amplitude of excitatory postsynaptic currents (EPSCs) and inversely correlated with the initial paired-pulse facilitation, suggesting that synapses with lower release probability (Pr) are more susceptible to the action of BDNF. To determine whether saturation of Pr could have masked the potentiation effect of BDNF in the stronger synapses, we lowered the initial Pr either by reducing the extracellular Ca2+ concentration ([Ca2+]o) or by bath application of adenosine. Synapses that were initially strong remained unaffected by BDNF under these conditions of reduced Pr. Thus, the lack of BDNF effect on synaptic efficacy cannot simply be accounted for by saturation of Pr, but rather may be due to intrinsic changes associated with synaptic maturation that might covary with Pr. Finally, the dependence on initial synaptic strength was also found for divergent outputs of the same presynaptic neuron, suggesting that synaptic terminals with different degrees of responsiveness to BDNF can coexist within in the same neuron.
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Affiliation(s)
- B Berninger
- Department of Biology, University of California San Diego, La Jolla 92093-0357, USA
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Olson EC, Schinder AF, Dantzker JL, Marcus EA, Spitzer NC, Harris WA. Properties of ectopic neurons induced by Xenopus neurogenin1 misexpression. Mol Cell Neurosci 1998; 12:281-99. [PMID: 9828092 DOI: 10.1006/mcne.1998.0712] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have examined cells cultured from ectoderm-misexpressing Neurogenin1 (Ngn1) to describe better the extent to which this gene can control aspects of neuronal phenotype including motility, morphology, excitability, and synaptic properties. Like primary spinal neurons which normally express Ngn1, cells in Ngn1-misexpressing cultures exhibit a motility-correlated behavior called circus movements prior to neuritogenesis. Misexpression of NeuroD also causes circus movements and later neuronal differentiation. GSK3beta, which inhibits NeuroD function in vivo, blocks both Ngn1-induced and NeuroD-induced neuronal differentiation, while Notch signaling inhibits only Ngn1-induced neuronal differentiation, confirming that NeuroD is downstream of Ngn1 and insensitive to Notch inhibition. While interfering with NeuroD function in ventral ectoderm inhibits both circus movements and neuronal differentiation, such inhibition in the neural plate inhibits only neuronal differentiation, suggesting that additional factors regulate circus movements in the neural ectoderm. Ngn1-misexpressing cells extend N-tubulin-positive neurites and exhibit tetrodotoxin-sensitive action potentials. Unlike the majority of cultured spinal neurons, however, Ngn1-misexpressing cells do not respond to glutamate and do not form functional synapses with myocytes, suggesting that these cells are either like Rohon-Beard sensory neurons or are not fully differentiated.
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Affiliation(s)
- E C Olson
- Department of Biology, University of California, San Diego, California, 92093, USA.
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50
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Schinder AF, Olson EC, Spitzer NC, Montal M. Mitochondrial dysfunction is a primary event in glutamate neurotoxicity. J Neurosci 1996; 16:6125-33. [PMID: 8815895 PMCID: PMC6579180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Excitotoxic neuronal death, associated with neurodegenerative disorders and hypoxic insults, results from excessive exposure to excitatory neurotransmitters. Glutamate neurotoxicity is triggered primarily by massive Ca2+ influx arising from overstimulation of the NMDA subtype of glutamate receptors. The underlying mechanisms, however, remain elusive. We have tested the hypothesis that mitochondria are primary targets in excitotoxicity by confocal imaging of intracellular Ca2+ ([Ca2+]i) and mitochondrial membrane potential (delta psi) on cultured rat hippocampal neurons. Sustained activation of NMDA receptors (20 min) elicits reversible elevation of [Ca2+]i. Longer activation (50 min) renders elevation of [Ca2+]i irreversible (Ca2+ overload). Susceptibility to NMDA-induced Ca2+ overload is increased when the 20 min stimuli are applied to neurons pretreated with electron transport chain inhibitors, thereby implicating mitochondria in [Ca2+]i homeostasis during excitotoxic challenges. Remarkably, delta psi exhibits prominent and persistent depolarization in response to NMDA, which closely parallels the incidence of neuronal death. Blockade of the mitochondrial permeability transition pore by cyclosporin A allows complete recovery of delta psi and prevents cell death. These results suggest that early mitochondrial damage plays a key role in induction of glutamate neurotoxicity.
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Affiliation(s)
- A F Schinder
- Department of Biology, University of California at San Diego, La Jolla 92093-0366, USA
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