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Saxon D, Alderman PJ, Sorrells SF, Vicini S, Corbin JG. Neuronal Subtypes and Connectivity of the Adult Mouse Paralaminar Amygdala. eNeuro 2024; 11:ENEURO.0119-24.2024. [PMID: 38811163 PMCID: PMC11208988 DOI: 10.1523/eneuro.0119-24.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/03/2024] [Accepted: 05/10/2024] [Indexed: 05/31/2024] Open
Abstract
The paralaminar nucleus of the amygdala (PL) comprises neurons that exhibit delayed maturation. PL neurons are born during gestation but mature during adolescent ages, differentiating into excitatory neurons. These late-maturing PL neurons contribute to the increase in size and cell number of the amygdala between birth and adulthood. However, the function of the PL upon maturation is unknown, as the region has only recently begun to be characterized in detail. In this study, we investigated key defining features of the adult mouse PL; the intrinsic morpho-electric properties of its neurons, and its input and output circuit connectivity. We identify two subtypes of excitatory neurons in the PL based on unsupervised clustering of electrophysiological properties. These subtypes are defined by differential action potential firing properties and dendritic architecture, suggesting divergent functional roles. We further uncover major axonal inputs to the adult PL from the main olfactory network and basolateral amygdala. We also find that axonal outputs from the PL project reciprocally to these inputs and to diverse targets including the amygdala, frontal cortex, hippocampus, hypothalamus, and brainstem. Thus, the adult mouse PL is centrally placed to play a major role in the integration of olfactory sensory information, to coordinate affective and autonomic behavioral responses to salient odor stimuli.
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Affiliation(s)
- David Saxon
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007
| | - Pia J Alderman
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Shawn F Sorrells
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
- Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Stefano Vicini
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington, DC 20007
| | - Joshua G Corbin
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011
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2
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Mortessagne P, Cartier E, Balia M, Fèvre M, Corailler F, Herry C, Abrous DN, Battefeld A, Pacary E. Genetic labeling of embryonically-born dentate granule neurons in young mice using the Penk Cre mouse line. Sci Rep 2024; 14:5022. [PMID: 38424161 PMCID: PMC10904803 DOI: 10.1038/s41598-024-55299-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 02/22/2024] [Indexed: 03/02/2024] Open
Abstract
The dentate gyrus (DG) of the hippocampus is a mosaic of dentate granule neurons (DGNs) accumulated throughout life. While many studies focused on the morpho-functional properties of adult-born DGNs, much less is known about DGNs generated during development, and in particular those born during embryogenesis. One of the main reasons for this gap is the lack of methods available to specifically label and manipulate embryonically-born DGNs. Here, we have assessed the relevance of the PenkCre mouse line as a genetic model to target this embryonically-born population. In young animals, PenkCre expression allows to tag neurons in the DG with positional, morphological and electrophysiological properties characteristic of DGNs born during the embryonic period. In addition, PenkCre+ cells in the DG are distributed in both blades along the entire septo-temporal axis. This model thus offers new possibilities to explore the functions of this underexplored population of embryonically-born DGNs.
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Affiliation(s)
- Pierre Mortessagne
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France
| | - Estelle Cartier
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France
| | - Maddalena Balia
- Univ. Bordeaux, CNRS, IMN, UMR 5293, 33000, Bordeaux, France
| | - Murielle Fèvre
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France
| | - Fiona Corailler
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France
| | - Cyril Herry
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France
| | - Djoher Nora Abrous
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France.
| | - Arne Battefeld
- Univ. Bordeaux, CNRS, IMN, UMR 5293, 33000, Bordeaux, France
| | - Emilie Pacary
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, 33000, Bordeaux, France.
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3
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Saxon D, Alderman PJ, Sorrells SF, Vicini S, Corbin JG. Neuronal subtypes and connectivity of the adult mouse paralaminar amygdala. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.11.575250. [PMID: 38260244 PMCID: PMC10802617 DOI: 10.1101/2024.01.11.575250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The paralaminar nucleus of the amygdala (PL) is comprised of neurons which exhibit delayed maturation. PL neurons are born during gestation but mature during adolescent ages, differentiating into excitatory neurons. The PL is prominent in the adult amygdala, contributing to its increased neuron number and relative size compared to childhood. However, the function of the PL is unknown, as the region has only recently begun to be characterized in detail. In this study, we investigated key defining features of the adult PL; the intrinsic morpho-electric properties of its neurons, and its input and output connectivity. We identify two subtypes of excitatory neurons in the PL based on unsupervised clustering of electrophysiological properties. These subtypes are defined by differential action potential firing properties and dendritic architecture, suggesting divergent functional roles. We further uncover major axonal inputs to the adult PL from the main olfactory network and basolateral amygdala. We also find that axonal outputs from the PL project reciprocally to major inputs, and to diverse targets including the amygdala, frontal cortex, hippocampus, hypothalamus, and brainstem. Thus, the adult PL is centrally placed to play a major role in the integration of olfactory sensory information, likely coordinating affective and autonomic behavioral responses to salient odor stimuli. Significance Statement Mammalian amygdala development includes a growth period from childhood to adulthood, believed to support emotional and social learning. This amygdala growth is partly due to the maturation of neurons during adolescence in the paralaminar amygdala. However, the functional properties of these neurons are unknown. In our recent studies, we characterized the paralaminar amygdala in the mouse. Here, we investigate the properties of the adult PL in the mouse, revealing the existence of two neuronal subtypes that may play distinct functional roles in the adult brain. We further reveal the brain-wide input and output connectivity of the PL, indicating that the PL combines olfactory cues for emotional processing and delivers information to regions associated with reward and autonomic states.
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4
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Tagliatti E, Desiato G, Mancinelli S, Bizzotto M, Gagliani MC, Faggiani E, Hernández-Soto R, Cugurra A, Poliseno P, Miotto M, Argüello RJ, Filipello F, Cortese K, Morini R, Lodato S, Matteoli M. Trem2 expression in microglia is required to maintain normal neuronal bioenergetics during development. Immunity 2024; 57:86-105.e9. [PMID: 38159572 PMCID: PMC10783804 DOI: 10.1016/j.immuni.2023.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 07/17/2023] [Accepted: 12/05/2023] [Indexed: 01/03/2024]
Abstract
Triggering receptor expressed on myeloid cells 2 (Trem2) is a myeloid cell-specific gene expressed in brain microglia, with variants that are associated with neurodegenerative diseases, including Alzheimer's disease. Trem2 is essential for microglia-mediated synaptic refinement, but whether Trem2 contributes to shaping neuronal development remains unclear. Here, we demonstrate that Trem2 plays a key role in controlling the bioenergetic profile of pyramidal neurons during development. In the absence of Trem2, developing neurons in the hippocampal cornus ammonis (CA)1 but not in CA3 subfield displayed compromised energetic metabolism, accompanied by reduced mitochondrial mass and abnormal organelle ultrastructure. This was paralleled by the transcriptional rearrangement of hippocampal pyramidal neurons at birth, with a pervasive alteration of metabolic, oxidative phosphorylation, and mitochondrial gene signatures, accompanied by a delay in the maturation of CA1 neurons. Our results unveil a role of Trem2 in controlling neuronal development by regulating the metabolic fitness of neurons in a region-specific manner.
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Affiliation(s)
- Erica Tagliatti
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy; Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Genni Desiato
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Sara Mancinelli
- Humanitas University, Department of Biomedical Sciences, Via Levi Montalicini 4, Pieve Emanuele 20072 Milan, Italy
| | - Matteo Bizzotto
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy; Humanitas University, Department of Biomedical Sciences, Via Levi Montalicini 4, Pieve Emanuele 20072 Milan, Italy
| | - Maria C Gagliani
- Cellular Electron Microscopy Laboratory, Department of Experimental Medicine (DIMES), Human Anatomy, Università di Genova, Via Antonio de Toni 14, 16132 Genova, Italy
| | - Elisa Faggiani
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | | | - Andrea Cugurra
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Paola Poliseno
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Matteo Miotto
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Rafael J Argüello
- Aix Marseille Univ, CNRS, INSERM, CIML, Centre d'Immunologie de Marseille-Luminy, Marseille, France
| | - Fabia Filipello
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy; Department of Psychiatry, Washington University School of Medicine, St. Louis, MO, USA
| | - Katia Cortese
- Cellular Electron Microscopy Laboratory, Department of Experimental Medicine (DIMES), Human Anatomy, Università di Genova, Via Antonio de Toni 14, 16132 Genova, Italy
| | - Raffaella Morini
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy
| | - Simona Lodato
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy; Humanitas University, Department of Biomedical Sciences, Via Levi Montalicini 4, Pieve Emanuele 20072 Milan, Italy
| | - Michela Matteoli
- IRCCS Humanitas Research Hospital, via Manzoni 56, Rozzano, 20089 Milan, Italy; Institute of Neuroscience - National Research Council, 20139 Milan, Italy.
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5
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Corrubia L, Huang A, Nguyen S, Shiflett MW, Jones MV, Ewell LA, Santhakumar V. Early deficits in dentate circuit and behavioral pattern separation after concussive brain injury. Exp Neurol 2023; 370:114578. [PMID: 37858696 PMCID: PMC10712990 DOI: 10.1016/j.expneurol.2023.114578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/28/2023] [Accepted: 10/16/2023] [Indexed: 10/21/2023]
Abstract
Traumatic brain injury leads to cellular and circuit changes in the dentate gyrus, a gateway to hippocampal information processing. Intrinsic granule cell firing properties and strong feedback inhibition in the dentate are proposed as critical to its ability to generate unique representation of similar inputs by a process known as pattern separation. Here we evaluate the impact of brain injury on cellular decorrelation of temporally patterned inputs in slices and behavioral discrimination of spatial locations in vivo one week after concussive lateral fluid percussion injury (FPI) in mice. Despite posttraumatic increases in perforant path evoked excitatory drive to granule cells and enhanced ΔFosB labeling, indicating sustained increase in excitability, the reliability of granule cell spiking was not compromised after FPI. Although granule cells continued to effectively decorrelate output spike trains recorded in response to similar temporally patterned input sets after FPI, their ability to decorrelate highly similar input patterns was reduced. In parallel, encoding of similar spatial locations in a novel object location task that involves the dentate inhibitory circuits was impaired one week after FPI. Injury induced changes in pattern separation were accompanied by loss of somatostatin expressing inhibitory neurons in the hilus. Together, these data suggest that the early posttraumatic changes in the dentate circuit undermine dentate circuit decorrelation of temporal input patterns as well as behavioral discrimination of similar spatial locations, both of which could contribute to deficits in episodic memory.
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Affiliation(s)
- Lucas Corrubia
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Andrew Huang
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | - Susan Nguyen
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA
| | | | - Mathew V Jones
- Department of Neuroscience, University of Wisconsin, Madison, WI 53705, USA
| | - Laura A Ewell
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA 92697, USA
| | - Vijayalakshmi Santhakumar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, CA 92521, USA.
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6
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Corrubia L, Huang A, Nguyen S, Shiflett MW, Jones MV, Ewell LA, Santhakumar V. Early Deficits in Dentate Circuit and Behavioral Pattern Separation after Concussive Brain Injury. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.22.546120. [PMID: 37745454 PMCID: PMC10515770 DOI: 10.1101/2023.06.22.546120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Traumatic brain injury leads to cellular and circuit changes in the dentate gyrus, a gateway to hippocampal information processing. Intrinsic granule cell firing properties and strong feedback inhibition in the dentate are proposed as critical to its ability to generate unique representation of similar inputs by a process known as pattern separation. Here we evaluate the impact of brain injury on cellular decorrelation of temporally patterned inputs in slices and behavioral discrimination of spatial locations in vivo one week after concussive lateral fluid percussion injury (FPI) in mice. Despite posttraumatic increases in perforant path evoked excitatory drive to granule cells and enhanced ΔFosB labeling, indicating sustained increase in excitability, the reliability of granule cell spiking was not compromised after FPI. Although granule cells continued to effectively decorrelate output spike trains recorded in response to similar temporally patterned input sets after FPI, their ability to decorrelate highly similar input patterns was reduced. In parallel, encoding of similar spatial locations in a novel object location task that involves the dentate inhibitory circuits was impaired one week after FPI. Injury induced changes in pattern separation were accompanied by loss of somatostatin expressing inhibitory neurons in the hilus. Together, these data suggest that the early posttraumatic changes in the dentate circuit undermine dentate circuit decorrelation of temporal input patterns as well as behavioral discrimination of similar spatial locations, both of which could contribute to deficits in episodic memory.
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Affiliation(s)
- Lucas Corrubia
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey 07103
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Andrew Huang
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | - Susan Nguyen
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
| | | | - Mathew V. Jones
- Department of Neuroscience, University of Wisconsin, Madison, WI, 53705
| | - Laura A. Ewell
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, California 92697
| | - Vijayalakshmi Santhakumar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, New Jersey 07103
- Department of Molecular, Cell and Systems Biology, University of California Riverside, Riverside, California 92521
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7
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Ash AM, Regele-Blasco E, Seib DR, Chahley E, Skelton PD, Luikart BW, Snyder JS. Adult-born neurons inhibit developmentally-born neurons during spatial learning. Neurobiol Learn Mem 2023; 198:107710. [PMID: 36572174 DOI: 10.1016/j.nlm.2022.107710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022]
Abstract
Ongoing neurogenesis in the dentate gyrus (DG) subregion of the hippocampus results in a heterogenous population of neurons. Immature adult-born neurons (ABNs) have physiological and anatomical properties that may give them a unique role in learning. For example, compared to older granule neurons, they have greater somatic excitability, which could facilitate their recruitment into memory traces. However, recruitment is also likely to depend on interactions with other DG neurons through processes such as lateral inhibition. Immature ABNs target inhibitory interneurons and, compared to older neurons, they receive less GABAergic inhibition. Thus, they may induce lateral inhibition of mature DG neurons while being less susceptible to inhibition themselves. To test this we used a chemogenetic approach to silence immature ABNs as rats learned a spatial water maze task, and measured activity (Fos expression) in ABNs and developmentally-born neurons (DBNs). A retrovirus expressing the inhibitory DREADD receptor, hM4Di, was injected into the dorsal DG of male rats at 6w to infect neurons born in adulthood. Animals were also injected with BrdU to label DBNs or ABNs. DBNs were significantly more active than immature 4-week-old ABNs. Silencing 4-week-old ABNs did not alter learning but it increased activity in DBNs. However, silencing ABNs did not affect activation in other ABNs within the DG. Silencing ABNs also did not alter Fos expression in parvalbumin- and somatostatin-expressing interneurons. Collectively, these results suggest that ABNs may directly inhibit DBN activity during hippocampal-dependent learning, which may be relevant for maintaining sparse hippocampal representations of experienced events.
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Affiliation(s)
- Alyssa M Ash
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Elena Regele-Blasco
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Désirée R Seib
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Erin Chahley
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Patrick D Skelton
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Bryan W Luikart
- Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, United States
| | - Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada.
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8
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Sun D, Mei L, Xiong WC. Dorsal Dentate Gyrus, a Key Regulator for Mood and Psychiatric Disorders. Biol Psychiatry 2023:S0006-3223(23)00009-4. [PMID: 36894487 DOI: 10.1016/j.biopsych.2023.01.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 12/06/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023]
Abstract
The dentate gyrus, a "gate" that controls the flow of information into the hippocampus, is critical for learning, memory, spatial navigation, and mood regulation. Several lines of evidence have demonstrated that deficits in dentate granule cells (DGCs) (e.g., loss of DGCs or genetic mutations in DGCs) contribute to the development of various psychiatric disorders, such as depression and anxiety disorders. Whereas ventral DGCs are believed to be critical for mood regulation, the functions of dorsal DGCs in this regard remain elusive. Here, we review the role of DGCs, in particular the dorsal DGCs, in the regulation of mood, their functional relationships with DGC development, and the contributions of dysfunctional DGCs to mental disorders.
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Affiliation(s)
- Dong Sun
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio; National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, Jilin, China
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio.
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9
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Adult-born dentate granule cells promote hippocampal population sparsity. Nat Neurosci 2022; 25:1481-1491. [PMID: 36216999 PMCID: PMC9630129 DOI: 10.1038/s41593-022-01176-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 09/01/2022] [Indexed: 01/13/2023]
Abstract
The dentate gyrus (DG) gates neocortical information flow to the hippocampus. Intriguingly, the DG also produces adult-born dentate granule cells (abDGCs) throughout the lifespan, but their contribution to downstream firing dynamics remains unclear. Here, we show that abDGCs promote sparser hippocampal population spiking during mnemonic processing of novel stimuli. By combining triple-(DG-CA3-CA1) ensemble recordings and optogenetic interventions in behaving mice, we show that abDGCs constitute a subset of high-firing-rate neurons with enhanced activity responses to novelty and strong modulation by theta oscillations. Selectively activating abDGCs in their 4-7-week post-birth period increases sparsity of hippocampal population patterns, whereas suppressing abDGCs reduces this sparsity, increases principal cell firing rates and impairs novel object recognition with reduced dimensionality of the network firing structure, without affecting single-neuron spatial representations. We propose that adult-born granule cells transiently support sparser hippocampal population activity structure for higher-dimensional responses relevant to effective mnemonic information processing.
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10
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Huszár R, Zhang Y, Blockus H, Buzsáki G. Preconfigured dynamics in the hippocampus are guided by embryonic birthdate and rate of neurogenesis. Nat Neurosci 2022; 25:1201-1212. [PMID: 35995878 PMCID: PMC10807234 DOI: 10.1038/s41593-022-01138-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 07/12/2022] [Indexed: 02/08/2023]
Abstract
The incorporation of new information into the hippocampal network is likely to be constrained by its innate architecture and internally generated activity patterns. However, the origin, organization and consequences of such patterns remain poorly understood. In the present study we show that hippocampal network dynamics are affected by sequential neurogenesis. We birthdated CA1 pyramidal neurons with in utero electroporation over 4 embryonic days, encompassing the peak of hippocampal neurogenesis, and compared their functional features in freely moving adult mice. Neurons of the same birthdate displayed distinct connectivity, coactivity across brain states and assembly dynamics. Same-birthdate neurons exhibited overlapping spatial representations, which were maintained across different environments. Overall, the wiring and functional features of CA1 pyramidal neurons reflected a combination of birthdate and the rate of neurogenesis. These observations demonstrate that sequential neurogenesis during embryonic development shapes the preconfigured forms of adult network dynamics.
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Affiliation(s)
- Roman Huszár
- Neuroscience Institute, New York University, New York, NY, USA.
- Center for Neural Science, New York University, New York, NY, USA.
| | - Yunchang Zhang
- Neuroscience Institute, New York University, New York, NY, USA
- Center for Neural Science, New York University, New York, NY, USA
| | - Heike Blockus
- Department of Neuroscience, Columbia University, New York, NY, USA
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY, USA
| | - György Buzsáki
- Neuroscience Institute, New York University, New York, NY, USA.
- Center for Neural Science, New York University, New York, NY, USA.
- Department of Neurology, Langone Medical Center, New York, NY, USA.
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11
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Abrous DN, Koehl M, Lemoine M. A Baldwin interpretation of adult hippocampal neurogenesis: from functional relevance to physiopathology. Mol Psychiatry 2022; 27:383-402. [PMID: 34103674 PMCID: PMC8960398 DOI: 10.1038/s41380-021-01172-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 05/03/2021] [Accepted: 05/12/2021] [Indexed: 02/05/2023]
Abstract
Hippocampal adult neurogenesis has been associated to many cognitive, emotional, and behavioral functions and dysfunctions, and its status as a selected effect or an "appendix of the brain" has been debated. In this review, we propose to understand hippocampal neurogenesis as the process underlying the "Baldwin effect", a particular situation in evolution where fitness does not rely on the natural selection of genetic traits, but on "ontogenetic adaptation" to a changing environment. This supports the view that a strong distinction between developmental and adult hippocampal neurogenesis is made. We propose that their functions are the constitution and the lifelong adaptation, respectively, of a basic repertoire of cognitive and emotional behaviors. This lifelong adaptation occurs through new forms of binding, i.e., association or dissociation of more basic elements. This distinction further suggests that a difference is made between developmental vulnerability (or resilience), stemming from dysfunctional (or highly functional) developmental hippocampal neurogenesis, and adult vulnerability (or resilience), stemming from dysfunctional (or highly functional) adult hippocampal neurogenesis. According to this hypothesis, developmental and adult vulnerability are distinct risk factors for various mental disorders in adults. This framework suggests new avenues for research on hippocampal neurogenesis and its implication in mental disorders.
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Affiliation(s)
- Djoher Nora Abrous
- Univ. Bordeaux, INSERM, Neurocentre Magendie, U1215, Neurogenesis and Pathophysiology group, F-33000, Bordeaux, France.
| | - Muriel Koehl
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocentre Magendie, U1215, Neurogenesis and Pathophysiology group, F-33000 Bordeaux, France
| | - Maël Lemoine
- grid.412041.20000 0001 2106 639XUniversity Bordeaux, CNRS, ImmunoConcEpT, UMR 5164, Bordeaux, France
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12
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Cavalieri D, Angelova A, Islah A, Lopez C, Bocchio M, Bollmann Y, Baude A, Cossart R. CA1 pyramidal cell diversity is rootedin the time of neurogenesis. eLife 2021; 10:69270. [PMID: 34723790 PMCID: PMC8660020 DOI: 10.7554/elife.69270] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 10/31/2021] [Indexed: 11/18/2022] Open
Abstract
Cellular diversity supports the computational capacity and flexibility of cortical circuits. Accordingly, principal neurons at the CA1 output node of the murine hippocampus are increasingly recognized as a heterogeneous population. Their genes, molecular content, intrinsic morpho-physiology, connectivity, and function seem to segregate along the main anatomical axes of the hippocampus. Since these axes reflect the temporal order of principal cell neurogenesis, we directly examined the relationship between birthdate and CA1 pyramidal neuron diversity, focusing on the ventral hippocampus. We used a genetic fate-mapping approach that allowed tagging three groups of age-matched principal neurons: pioneer, early-, and late-born. Using a combination of neuroanatomy, slice physiology, connectivity tracing, and cFos staining in mice, we show that birthdate is a strong predictor of CA1 principal cell diversity. We unravel a subpopulation of pioneer neurons recruited in familiar environments with remarkable positioning, morpho-physiological features, and connectivity. Therefore, despite the expected plasticity of hippocampal circuits, given their role in learning and memory, the diversity of their main components is also partly determined at the earliest steps of development.
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Affiliation(s)
| | | | - Anas Islah
- INMED, INSERM Aix-Marseille University, marseille, France
| | | | | | | | - Agnès Baude
- INMED, French Institute of Health and Medical Research, Marseille, France
| | - Rosa Cossart
- INMED, French Institute of Health and Medical Research, Marseille, France
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13
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Abstract
In mammals, the selective transformation of transient experience into stored memory occurs in the hippocampus, which develops representations of specific events in the context in which they occur. In this review, we focus on the development of hippocampal circuits and the self-organized dynamics embedded within them since the latter critically support the role of the hippocampus in learning and memory. We first discuss evidence that adult hippocampal cells and circuits are sculpted by development as early as during embryonic neurogenesis. We argue that these primary developmental programs provide a scaffold onto which later experience of the external world can be grafted. Next, we review the different sequences in the development of hippocampal cells and circuits at anatomical and functional levels. We cover a period extending from neurogenesis and migration to the appearance of phenotypic diversity within hippocampal cells, and their wiring into functional networks. We describe the progressive emergence of network dynamics in the hippocampus, from sensorimotor-driven early sharp waves to sequences of place cells tracking relational information. We outline the critical turn points and discontinuities in that developmental journey, and close by formulating open questions. We propose that rewinding the process of hippocampal development helps understand the main organization principles of memory circuits.
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Affiliation(s)
- Rosa Cossart
- Inserm, INMED, Turing Center for Living Systems, Aix Marseille University, Marseille, France
| | - Rustem Khazipov
- Inserm, INMED, Turing Center for Living Systems, Aix Marseille University, Marseille, France.,Laboratory of Neurobiology, Kazan Federal University, Kazan Russia
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14
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Shabangu T, Chen HL, Zhuang ZH, Pierani A, Chen CFF, Chou SJ. Specific contribution of neurons from the Dbx1 lineage to the piriform cortex. Sci Rep 2021; 11:8349. [PMID: 33863910 PMCID: PMC8052341 DOI: 10.1038/s41598-021-86512-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/15/2021] [Indexed: 11/20/2022] Open
Abstract
The piriform cortex (PC) is a major cortical processing center for the sense of smell that receives direct inputs from the olfactory bulb. In mice, the PC consists of three neuronal layers, which are populated by cells with distinct developmental origins. One origin of PC neurons is the pool of Dbx1-expressing neural progenitors located in the ventral pallium at the pallial-subpallial boundary. Since the precise mechanisms of PC neuron development are largely unknown, we sought to define the distribution, timing of neurogenesis, morphology and projection patterns of PC neurons from the Dbx1 lineage. We found that Dbx1-lineage neurons are preferentially distributed in layer 2 and enriched in the ventral portion of the PC. Further, Dbx1 neurons are early-born neurons and contribute to most neuronal subtypes in the PC. Our data also revealed an enrichment of Dbx1-lineage neurons in the ventral anterior PC that project to the orbitofrontal cortex. These findings suggest a specific association between the developmental origin of PC neurons and their neuronal properties.
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Affiliation(s)
- Thando Shabangu
- Molecular Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Hung-Lun Chen
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Zi-Hui Zhuang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan
| | - Alessandra Pierani
- Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Université de Paris, F-75015, Paris, France
- Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Université de Paris, F-75014, Paris, France
| | - Chien-Fu F Chen
- Molecular Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
| | - Shen-Ju Chou
- Molecular Cell Biology, Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan.
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei, Taiwan.
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15
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Sun D, Milibari L, Pan JX, Ren X, Yao LL, Zhao Y, Shen C, Chen WB, Tang FL, Lee D, Zhang JS, Mei L, Xiong WC. Critical Roles of Embryonic Born Dorsal Dentate Granule Neurons for Activity-Dependent Increases in BDNF, Adult Hippocampal Neurogenesis, and Antianxiety-like Behaviors. Biol Psychiatry 2021; 89:600-614. [PMID: 33183762 PMCID: PMC7889658 DOI: 10.1016/j.biopsych.2020.08.026] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 08/11/2020] [Accepted: 08/31/2020] [Indexed: 11/18/2022]
Abstract
BACKGROUND Dentate gyrus (DG), a "gate" that controls information flow into the hippocampus, plays important roles in regulating both cognitive (e.g., spatial learning and memory) and mood behaviors. Deficits in DG neurons contribute to the pathogenesis of not only neurological, but also psychiatric, disorders, such as anxiety disorder. Whereas DG's function in spatial learning and memory has been extensively investigated, its role in regulating anxiety remains elusive. METHODS Using c-Fos to mark DG neuron activation, we identified a group of embryonic born dorsal DG (dDG) neurons, which were activated by anxiogenic stimuli and specifically express osteocalcin (Ocn)-Cre. We further investigated their functions in regulating anxiety and the underlying mechanisms by using a combination of chemogenetic, electrophysiological, and RNA-sequencing methods. RESULTS The Ocn-Cre+ dDG neurons were highly active in response to anxiogenic environment but had lower excitability and fewer presynaptic inputs than those of Ocn-Cre- or adult born dDG neurons. Activating Ocn-Cre+ dDG neurons suppressed anxiety-like behaviors and increased adult DG neurogenesis, whereas ablating or chronically inhibiting Ocn-Cre+ dDG neurons exacerbated anxiety-like behaviors, impaired adult DG neurogenesis, and abolished activity (e.g., voluntary wheel running)-induced anxiolytic effect and adult DG neurogenesis. RNA-sequencing screening for factors induced by activation of Ocn-Cre+ dDG neurons identified BDNF, which was required for Ocn-Cre+ dDG neurons mediated antianxiety-like behaviors and adult DG neurogenesis. CONCLUSIONS These results demonstrate critical functions of Ocn-Cre+ dDG neurons in suppressing anxiety-like behaviors but promoting adult DG neurogenesis, and both functions are likely through activation of BDNF.
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Affiliation(s)
- Dong Sun
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Leena Milibari
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Jin-Xiu Pan
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Xiao Ren
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Ling-Ling Yao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Yang Zhao
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Chen Shen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Wen-Bing Chen
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Fu-Lei Tang
- Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Daehoon Lee
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Jun-Shi Zhang
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Lin Mei
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Wen-Cheng Xiong
- Department of Neurosciences, School of Medicine, Case Western Reserve University, Cleveland, Ohio; Louis Stokes Cleveland Veterans Affairs Medical Center, Cleveland, Ohio; Department of Neuroscience and Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia.
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16
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Huckleberry KA, Shansky RM. The unique plasticity of hippocampal adult-born neurons: Contributing to a heterogeneous dentate. Hippocampus 2021; 31:543-556. [PMID: 33638581 DOI: 10.1002/hipo.23318] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 01/15/2021] [Accepted: 02/09/2021] [Indexed: 12/14/2022]
Abstract
The dentate gyrus (DG) of the hippocampus is evolutionarily conserved as one of the few sites of adult neurogenesis in mammals. Although there is clear evidence that neurogenesis is necessary for healthy hippocampal function, whether adult-born neurons are simply integrated into existing hippocampal networks to serve a similar purpose to that of developmentally born neurons or whether they represent a discrete cell population with unique functions remains less clear. In this review, we consider evidence for discrete cellular, synaptic, and structural features of adult-born DG neurons, suggesting that neurogenesis contributes to the formation of a heterogeneous DG. We therefore propose that hippocampal neurogenesis creates a specialized neuronal subpopulation that may play a key role in hippocampal functions like episodic memory. We note critical gaps in this extensive body of work, including a general failure to include female animals in relevant research and a need for more precise consideration of intrahippocampal neuroanatomy.
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Affiliation(s)
- Kylie A Huckleberry
- Behavioral Neuroscience Program, Department of Psychology, Northeastern University, Boston, Massachusetts, USA
| | - Rebecca M Shansky
- Behavioral Neuroscience Program, Department of Psychology, Northeastern University, Boston, Massachusetts, USA
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17
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Pléau C, Peret A, Pearlstein E, Scalfati T, Vigier A, Marti G, Michel FJ, Marissal T, Crépel V. Dentate Granule Cells Recruited in the Home Environment Display Distinctive Properties. Front Cell Neurosci 2021; 14:609123. [PMID: 33519383 PMCID: PMC7843370 DOI: 10.3389/fncel.2020.609123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/23/2020] [Indexed: 11/13/2022] Open
Abstract
The dentate granule cells (DGCs) play a crucial role in learning and memory. Many studies have described the role and physiological properties of these sparsely active neurons using different behavioral contexts. However, the morpho-functional features of DGCs recruited in mice maintained in their home cage (without training), considered as a baseline condition, have not yet been established. Using fosGFP transgenic mice, we observed ex vivo that DGCs recruited in animals maintained in the home cage condition are mature neurons that display a longer dendritic tree and lower excitability compared with non-activated cells. The higher GABAA receptor-mediated shunting inhibition contributes to the lower excitability of DGCs activated in the home environment by shifting the input resistance towards lower values. Remarkably, that shunting inhibition is neither observed in non-activated DGCs nor in DGCs activated during training in virtual reality. In short, our results suggest that strong shunting inhibition and reduced excitability could constitute a distinctive neural signature of mature DGCs recruited in the context of the home environment.
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Affiliation(s)
- Claire Pléau
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
| | - Angélique Peret
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
| | | | - Thomas Scalfati
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
| | - Alexandre Vigier
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
| | | | | | - Thomas Marissal
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
| | - Valérie Crépel
- INMED, INSERM UMR1249, Aix-Marseille University, Marseille, France
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18
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Masachs N, Charrier V, Farrugia F, Lemaire V, Blin N, Mazier W, Tronel S, Montaron MF, Ge S, Marsicano G, Cota D, Deroche-Gamonet V, Herry C, Abrous DN. The temporal origin of dentate granule neurons dictates their role in spatial memory. Mol Psychiatry 2021; 26:7130-7140. [PMID: 34526669 PMCID: PMC8873024 DOI: 10.1038/s41380-021-01276-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 07/20/2021] [Indexed: 11/27/2022]
Abstract
The dentate gyrus is one of the only brain regions that continues its development after birth in rodents. Adolescence is a very sensitive period during which cognitive competences are programmed. We investigated the role of dentate granule neurons (DGNs) born during adolescence in spatial memory and compared them with those generated earlier in life (in embryos or neonates) or during adulthood by combining functional imaging, retroviral and optogenetic tools to tag and silence DGNs. By imaging DGNs expressing Zif268, a proxy for neuronal activity, we found that neurons generated in adolescent rats (and not embryos or neonates) are transiently involved in spatial memory processing. In contrast, adult-generated DGNs are recruited at a later time point when animals are older. A causal relationship between the temporal origin of DGNs and spatial memory was confirmed by silencing DGNs in behaving animals. Our results demonstrate that the emergence of spatial memory depends on neurons born during adolescence, a function later assumed by neurons generated during adulthood.
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Affiliation(s)
- Nuria Masachs
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Vanessa Charrier
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Fanny Farrugia
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Valerie Lemaire
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Nicolas Blin
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Wilfrid Mazier
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Energy Balance and Obesity Group, U1215, F-33000 Bordeaux, France
| | - Sophie Tronel
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Marie-Françoise Montaron
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000 Bordeaux, France
| | - Shaoyu Ge
- grid.36425.360000 0001 2216 9681Program in Neuroscience, SUNY at Stony Brook, Stony Brook, New York, NY USA
| | - Giovanni Marsicano
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Endocannabinoids and Neuroadaptation Group, U1215, F-33000 Bordeaux, France
| | - Daniela Cota
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Energy Balance and Obesity Group, U1215, F-33000 Bordeaux, France
| | - Véronique Deroche-Gamonet
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Psychobiology of Drug Addiction Group, U1215, F-33000 Bordeaux, France
| | - Cyril Herry
- grid.412041.20000 0001 2106 639XUniv. Bordeaux, INSERM, Neurocenter Magendie, Neuronal Circuits of Associative Learning Group, U1215, F-33000 Bordeaux, France
| | - Djoher Nora Abrous
- Univ. Bordeaux, INSERM, Neurocenter Magendie, Neurogenesis and Pathophysiology Group, U1215, F-33000, Bordeaux, France.
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19
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Abstract
Neural stem cells (NSCs) persist into adulthood in the subgranular zone (SGZ) of the dentate gyrus in the hippocampus and in the ventricular-subventricular zone (V-SVZ) of the lateral ventricles, where they generate new neurons and glia cells that contribute to neural plasticity. A better understanding of the developmental process that enables NSCs to persist beyond development will provide insight into factors that determine the size and properties of the adult NSC pool and thus the capacity for life-long neurogenesis in the adult mammalian brain. We review current knowledge regarding the developmental origins of adult NSCs and the developmental process by which embryonic NSCs transition into their adult form. We also discuss potential mechanisms that might regulate proper establishment of the adult NSC pool, and propose future directions of research that will be key to unraveling how NSCs transform to establish the adult NSC pool in the mammalian brain.
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Affiliation(s)
- Allison M Bond
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, United States; Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, United States; The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
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20
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Gupta A, Proddutur A, Chang YJ, Raturi V, Guevarra J, Shah Y, Elgammal FS, Santhakumar V. Dendritic morphology and inhibitory regulation distinguish dentate semilunar granule cells from granule cells through distinct stages of postnatal development. Brain Struct Funct 2020; 225:2841-2855. [PMID: 33124674 DOI: 10.1007/s00429-020-02162-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 10/15/2020] [Indexed: 12/18/2022]
Abstract
Semilunar granule cells (SGCs) have been proposed as a morpho-functionally distinct class of hippocampal dentate projection neurons contributing to feedback inhibition and memory processing in juvenile rats. However, the structural and physiological features that can reliably classify granule cells (GCs) from SGCs through postnatal development remain unresolved. Focusing on postnatal days 11-13, 28-42, and > 120, corresponding with human infancy, adolescence, and adulthood, we examined the somato-dendritic morphology and inhibitory regulation in SGCs and GCs to determine the cell-type specific features. Unsupervised cluster analysis confirmed that morphological features reliably distinguish SGCs from GCs irrespective of animal age. SGCs maintain higher spontaneous inhibitory postsynaptic current (sIPSC) frequency than GCs from infancy through adulthood. Although sIPSC frequency in SGCs was particularly enhanced during adolescence, sIPSC amplitude and cumulative charge transfer declined from infancy to adulthood and were not different between GCs and SGCs. Extrasynaptic GABA current amplitude peaked in adolescence in both cell types and was significantly greater in SGCs than in GCs only during adolescence. Although GC input resistance was higher than in SGCs during infancy and adolescence, input resistance decreased with developmental age in GCs, while it progressively increased in SGCs. Consequently, GCs' input resistance was significantly lower than SGCs in adults. The data delineate the structural features that can reliably distinguish GCs from SGCs through development. The results reveal developmental differences in passive membrane properties and steady-state inhibition between GCs and SGCs which could confound their use in classifying the cell types.
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Affiliation(s)
- Akshay Gupta
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA.,Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Archana Proddutur
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA.,Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA
| | - Yun-Juan Chang
- Office of Advance Research Computing, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Vidhatri Raturi
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Jenieve Guevarra
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Yash Shah
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Fatima S Elgammal
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA
| | - Vijayalakshmi Santhakumar
- Department of Pharmacology, Physiology and Neuroscience, Rutgers New Jersey Medical School, Newark, NJ, 07103, USA. .,Department of Molecular, Cell and Systems Biology, University of California, Riverside, CA, 92521, USA.
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21
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Zhang X, Schlögl A, Jonas P. Selective Routing of Spatial Information Flow from Input to Output in Hippocampal Granule Cells. Neuron 2020; 107:1212-1225.e7. [PMID: 32763145 PMCID: PMC7523402 DOI: 10.1016/j.neuron.2020.07.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/22/2020] [Accepted: 07/10/2020] [Indexed: 11/18/2022]
Abstract
Dentate gyrus granule cells (GCs) connect the entorhinal cortex to the hippocampal CA3 region, but how they process spatial information remains enigmatic. To examine the role of GCs in spatial coding, we measured excitatory postsynaptic potentials (EPSPs) and action potentials (APs) in head-fixed mice running on a linear belt. Intracellular recording from morphologically identified GCs revealed that most cells were active, but activity level varied over a wide range. Whereas only ∼5% of GCs showed spatially tuned spiking, ∼50% received spatially tuned input. Thus, the GC population broadly encodes spatial information, but only a subset relays this information to the CA3 network. Fourier analysis indicated that GCs received conjunctive place-grid-like synaptic input, suggesting code conversion in single neurons. GC firing was correlated with dendritic complexity and intrinsic excitability, but not extrinsic excitatory input or dendritic cable properties. Thus, functional maturation may control input-output transformation and spatial code conversion.
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Affiliation(s)
- Xiaomin Zhang
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Alois Schlögl
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria
| | - Peter Jonas
- Cellular Neuroscience, IST Austria (Institute of Science and Technology Austria), Am Campus 1, 3400 Klosterneuburg, Austria.
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22
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Bocchio M, Gouny C, Angulo-Garcia D, Toulat T, Tressard T, Quiroli E, Baude A, Cossart R. Hippocampal hub neurons maintain distinct connectivity throughout their lifetime. Nat Commun 2020; 11:4559. [PMID: 32917906 PMCID: PMC7486410 DOI: 10.1038/s41467-020-18432-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 08/20/2020] [Indexed: 12/13/2022] Open
Abstract
The temporal embryonic origins of cortical GABA neurons are critical for their specialization. In the neonatal hippocampus, GABA cells born the earliest (ebGABAs) operate as ‘hubs’ by orchestrating population synchrony. However, their adult fate remains largely unknown. To fill this gap, we have examined CA1 ebGABAs using a combination of electrophysiology, neurochemical analysis, optogenetic connectivity mapping as well as ex vivo and in vivo calcium imaging. We show that CA1 ebGABAs not only operate as hubs during development, but also maintain distinct morpho-physiological and connectivity profiles, including a bias for long-range targets and local excitatory inputs. In vivo, ebGABAs are activated during locomotion, correlate with CA1 cell assemblies and display high functional connectivity. Hence, ebGABAs are specified from birth to ensure unique functions throughout their lifetime. In the adult brain, this may take the form of a long-range hub role through the coordination of cell assemblies across distant regions. In the neonatal hippocampus, GABA cells born the earliest operate as ‘hubs’ by orchestrating population synchrony. Here, the authors show that the earliest born GABAergic cells in the hippocampal CA1 region maintain distinct anatomical and functional properties throughout their lifetime.
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Affiliation(s)
- Marco Bocchio
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France.
| | - Claire Gouny
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France
| | - David Angulo-Garcia
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France.,Grupo de Modelado Computacional-Dinámica y Complejidad de Sistemas, Instituto de Matemáticas Aplicadas, Universidad de Cartagena, 130001, Cartagena, Colombia
| | - Tom Toulat
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France
| | - Thomas Tressard
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France
| | - Eleonora Quiroli
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France
| | - Agnès Baude
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France
| | - Rosa Cossart
- INMED (INSERM U1249), Aix-Marseille University, Turing Center for Living Systems (CENTURI), Parc Scientifique de Luminy, 13273, Marseille, France.
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23
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Semilunar Granule Cells Are the Primary Source of the Perisomatic Excitatory Innervation onto Parvalbumin-Expressing Interneurons in the Dentate Gyrus. eNeuro 2020; 7:ENEURO.0323-19.2020. [PMID: 32571963 PMCID: PMC7340841 DOI: 10.1523/eneuro.0323-19.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 11/21/2022] Open
Abstract
We analyzed the origin and relevance of the perisomatic excitatory inputs on the parvalbumin interneurons of the granule cell layer in mouse. Confocal analysis of the glutamatergic innervation showed that it represents ∼50% of the perisomatic synapses that parvalbumin cells receive. This excitatory input may originate from granule cell collaterals, the mossy cells, or even supramammillary nucleus. First, we assessed the input from the mossy cells on parvalbumin interneurons. Axon terminals of mossy cells were visualized by their calretinin content. Using multicolor confocal microscopy, we observed that less than 10% of perisomatic excitatory innervation of parvalbumin cells could originate from mossy cells. Correlative light and electron microscopy revealed that innervation from mossy cells, although present, was indeed infrequent, except for those parvalbumin cells whose somata were located in the inner molecular layer. Second, we investigated the potential input from supramammillary nucleus on parvalbumin cell somata using anterograde tracing or immunocytochemistry against vesicular glutamate transporter 2 (VGLUT2) and found only occasional contacts. Third, we intracellularly filled dentate granule cells in acute slice preparations using whole-cell recording and examined whether their axon collaterals target parvalbumin interneurons. We found that typical granule cells do not innervate the perisomatic region of these GABAergic cells. In sharp contrast, semilunar granule cells (SGCs), a scarce granule cell subtype often contacted the parvalbumin cell soma and proximal dendrites. Our data, therefore, show that perisomatic excitatory drive of parvalbumin interneurons in the granular layer of the dentate gyrus is abundant and originates primarily from SGCs.
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Adult-Born Hippocampal Neurons Undergo Extended Development and Are Morphologically Distinct from Neonatally-Born Neurons. J Neurosci 2020; 40:5740-5756. [PMID: 32571837 DOI: 10.1523/jneurosci.1665-19.2020] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/28/2020] [Accepted: 05/04/2020] [Indexed: 11/21/2022] Open
Abstract
During immature stages, adult-born neurons pass through critical periods for survival and plasticity. It is generally assumed that by 2 months of age adult-born neurons are mature and equivalent to the broader neuronal population, raising questions of how they might contribute to hippocampal function in old age when neurogenesis has declined. However, few have examined adult-born neurons beyond the critical period or directly compared them to neurons born in infancy. Here, we used a retrovirus to visualize functionally relevant morphological features of 2- to 24-week-old adult-born neurons in male rats. From 2 to 7 weeks, neurons grew and attained a relatively mature phenotype. However, several features of 7-week-old neurons suggested a later wave of growth: these neurons had larger nuclei, thicker dendrites, and more dendritic filopodia than all other groups. Indeed, between 7 and 24 weeks, adult-born neurons gained additional dendritic branches, formed a second primary dendrite, acquired more mushroom spines, and had enlarged mossy fiber presynaptic terminals. Compared with neonatal-born neurons, old adult-born neurons had greater spine density, larger presynaptic terminals, and more putative efferent filopodial contacts onto inhibitory neurons. By integrating rates of cell birth and growth across the life span, we estimate that adult neurogenesis ultimately produces half of the cells and the majority of spines in the dentate gyrus. Critically, protracted development contributes to the plasticity of the hippocampus through to the end of life, even after cell production declines. Persistent differences from neonatal-born neurons may additionally endow adult-born neurons with unique functions even after they have matured.SIGNIFICANCE STATEMENT Neurogenesis occurs in the hippocampus throughout adult life and contributes to memory and emotion. It is generally assumed that new neurons have the greatest impact on behavior when they are immature and plastic. However, since neurogenesis declines dramatically with age, it is unclear how they might contribute to behavior later in life when cell proliferation has slowed. Here we find that newborn neurons mature over many months in rats and may end up with distinct morphological features compared with neurons born in infancy. Using a mathematical model, we estimate that a large fraction of neurons is added in adulthood. Moreover, their extended growth produces a reserve of plasticity that persists even after neurogenesis has declined to low rates.
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Erwin SR, Sun W, Copeland M, Lindo S, Spruston N, Cembrowski MS. A Sparse, Spatially Biased Subtype of Mature Granule Cell Dominates Recruitment in Hippocampal-Associated Behaviors. Cell Rep 2020; 31:107551. [DOI: 10.1016/j.celrep.2020.107551] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Revised: 02/14/2020] [Accepted: 03/24/2020] [Indexed: 12/27/2022] Open
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Ciric T, Cahill SP, Snyder JS. Dentate gyrus neurons that are born at the peak of development, but not before or after, die in adulthood. Brain Behav 2019; 9:e01435. [PMID: 31576673 PMCID: PMC6790299 DOI: 10.1002/brb3.1435] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/14/2019] [Indexed: 12/14/2022] Open
Abstract
INTRODUCTION In the dentate gyrus of the rodent hippocampus, neurogenesis begins prenatally and continues to the end of life. Adult-born neurons often die in the first few weeks after mitosis, but those that survive to 1 month persist indefinitely. In contrast, neurons born at the peak of development are initially stable but can die later in adulthood. Physiological and pathological changes in the hippocampus may therefore result from both the addition of new neurons and the loss of older neurons. The extent of neuronal loss remains unclear since no studies have examined whether neurons born at other stages of development also undergo delayed cell death. METHODS We used BrdU to label dentate granule cells that were born in male rats on embryonic day 19 (E19; before the developmental peak), postnatal day 6 (P6; peak), and P21 (after the peak). We quantified BrdU+ neurons in separate groups of rats at 2 and 6 months post-BrdU injection to estimate cell death in young adulthood. RESULTS Consistent with previous work, there was a 15% loss of P6-born neurons between 2 and 6 months of age. In contrast, E19- or P21-born neurons were stable throughout young adulthood. DISCUSSION Delayed death of P6-born neurons suggests these cells may play a unique role in hippocampal plasticity adulthood, for example, by contributing to the turnover of hippocampal memory. Their loss may also play a role in disorders that are characterized by hippocampal atrophy.
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Affiliation(s)
- Tina Ciric
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Shaina P Cahill
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
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