1
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Sorrells SF. Which neurodevelopmental processes continue in humans after birth? Front Neurosci 2024; 18:1434508. [PMID: 39308952 PMCID: PMC11412957 DOI: 10.3389/fnins.2024.1434508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Accepted: 08/09/2024] [Indexed: 09/25/2024] Open
Abstract
Once we are born, the number and location of nerve cells in most parts of the brain remain unchanged. These types of structural changes are therefore a significant form of flexibility for the neural circuits where they occur. In humans, the postnatal birth of neurons is limited; however, neurons do continue to migrate into some brain regions throughout infancy and even into adolescence. In human infants, multiple migratory pathways deliver interneurons to destinations across the frontal and temporal lobe cortex. Shorter-range migration of excitatory neurons also appears to continue during adolescence, particularly near the amygdala paralaminar nucleus, a region that follows a delayed trajectory of growth from infancy to adulthood. The significance of the timing for when different brain regions recruit new neurons through these methods is unknown; however, both processes of protracted migration and maturation are prominent in humans. Mechanisms like these that reconfigure neuronal circuits are a substrate for critical periods of plasticity and could contribute to distinctive circuit functionality in human brains.
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2
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Alonso M, Petit AC, Lledo PM. The impact of adult neurogenesis on affective functions: of mice and men. Mol Psychiatry 2024; 29:2527-2542. [PMID: 38499657 DOI: 10.1038/s41380-024-02504-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/20/2024]
Abstract
In most mammals, new neurons are not only produced during embryogenesis but also after birth. Soon after adult neurogenesis was discovered, the influence of recruiting new neurons on cognitive functions, especially on memory, was documented. Likewise, the late process of neuronal production also contributes to affective functions, but this outcome was recognized with more difficulty. This review covers hypes and hopes of discovering the influence of newly-generated neurons on brain circuits devoted to affective functions. If the possibility of integrating new neurons into the adult brain is a commonly accepted faculty in the realm of mammals, the reluctance is strong when it comes to translating this concept to humans. Compiling data suggest now that new neurons are derived not only from stem cells, but also from a population of neuroblasts displaying a protracted maturation and ready to be engaged in adult brain circuits, under specific signals. Here, we discuss the significance of recruiting new neurons in the adult brain circuits, specifically in the context of affective outcomes. We also discuss the fact that adult neurogenesis could be the ultimate cellular process that integrates elements from both the internal and external environment to adjust brain functions. While we must be critical and beware of the unreal promises that Science could generate sometimes, it is important to continue exploring the potential of neural recruitment in adult primates. Reporting adult neurogenesis in humankind contributes to a new vision of humans as mammals whose brain continues to develop throughout life. This peculiar faculty could one day become the target of treatment for mental health, cognitive disorders, and elderly-associated diseases. The vision of an adult brain which never stops integrating new neurons is a real game changer for designing new therapeutic interventions to treat mental disorders associated with substantial morbidity, mortality, and social costs.
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Affiliation(s)
- Mariana Alonso
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Action Unit, F-75015, Paris, France
| | - Anne-Cécile Petit
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Action Unit, F-75015, Paris, France
- Pôle Hospitalo-Universitaire Psychiatrie Paris 15, GHU Paris Psychiatry and Neurosciences, Hôpital Sainte-Anne, Paris, France
| | - Pierre-Marie Lledo
- Institut Pasteur, Université Paris Cité, CNRS UMR 3571, Perception and Action Unit, F-75015, Paris, 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. 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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4
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Alderman PJ, Saxon D, Torrijos-Saiz LI, Sharief M, Page CE, Baroudi JK, Biagiotti SW, Butyrkin VA, Melamed A, Kuo CT, Vicini S, García-Verdugo JM, Herranz-Pérez V, Corbin JG, Sorrells SF. Delayed maturation and migration of excitatory neurons in the juvenile mouse paralaminar amygdala. Neuron 2024; 112:574-592.e10. [PMID: 38086370 PMCID: PMC10922384 DOI: 10.1016/j.neuron.2023.11.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 05/05/2023] [Accepted: 11/09/2023] [Indexed: 02/12/2024]
Abstract
The human amygdala paralaminar nucleus (PL) contains many immature excitatory neurons that undergo prolonged maturation from birth to adulthood. We describe a previously unidentified homologous PL region in mice that contains immature excitatory neurons and has previously been considered part of the amygdala intercalated cell clusters or ventral endopiriform cortex. Mouse PL neurons are born embryonically, not from postnatal neurogenesis, despite a subset retaining immature molecular and morphological features in adults. During juvenile-adolescent ages (P21-P35), the majority of PL neurons undergo molecular, structural, and physiological maturation, and a subset of excitatory PL neurons migrate into the adjacent endopiriform cortex. Alongside these changes, PL neurons develop responses to aversive and appetitive olfactory stimuli. The presence of this homologous region in both humans and mice points to the significance of this conserved mechanism of neuronal maturation and migration during adolescence, a key time period for amygdala circuit maturation and related behavioral changes.
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Affiliation(s)
- Pia J Alderman
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - David Saxon
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011, USA; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Lucía I Torrijos-Saiz
- Laboratory of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Comparative Neurobiology, University of Valencia, CIBERNED-ISCIII, Valencia 46980, Spain
| | - Malaz Sharief
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Chloe E Page
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Jude K Baroudi
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Sean W Biagiotti
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Vladimir A Butyrkin
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011, USA; Neuroscience and Cognitive Science Program, University of Maryland, College Park, MD 20742, USA
| | - Anna Melamed
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Chay T Kuo
- Department of Cell Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Stefano Vicini
- Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20007, USA; Department of Pharmacology & Physiology, Georgetown University Medical Center, Washington, DC 20007, USA
| | - Jose M García-Verdugo
- Laboratory of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Comparative Neurobiology, University of Valencia, CIBERNED-ISCIII, Valencia 46980, Spain; Department of Cell Biology, Functional Biology and Physical Anthropology, University of Valencia, Burjassot 46100, Spain
| | - Vicente Herranz-Pérez
- Laboratory of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Comparative Neurobiology, University of Valencia, CIBERNED-ISCIII, Valencia 46980, Spain; Department of Cell Biology, Functional Biology and Physical Anthropology, University of Valencia, Burjassot 46100, Spain
| | - Joshua G Corbin
- Center for Neuroscience Research, Children's Research Institute, Children's National Hospital, Washington, DC 20011, USA
| | - Shawn F Sorrells
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15260, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, Pittsburgh, PA 15260, USA.
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5
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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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6
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Loef D, Tendolkar I, van Eijndhoven PFP, Hoozemans JJM, Oudega ML, Rozemuller AJM, Lucassen PJ, Dols A, Dijkstra AA. Electroconvulsive therapy is associated with increased immunoreactivity of neuroplasticity markers in the hippocampus of depressed patients. Transl Psychiatry 2023; 13:355. [PMID: 37981649 PMCID: PMC10658169 DOI: 10.1038/s41398-023-02658-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 10/23/2023] [Accepted: 11/07/2023] [Indexed: 11/21/2023] Open
Abstract
Electroconvulsive therapy (ECT) is an effective therapy for depression, but its cellular effects on the human brain remain elusive. In rodents, electroconvulsive shocks increase proliferation and the expression of plasticity markers in the hippocampal dentate gyrus (DG), suggesting increased neurogenesis. Furthermore, MRI studies in depressed patients have demonstrated increases in DG volume after ECT, that were notably paralleled by a decrease in depressive mood scores. Whether ECT also triggers cellular plasticity, inflammation or possibly injury in the human hippocampus, was unknown. We here performed a first explorative, anatomical study on the human post-mortem hippocampus of a unique, well-documented cohort of bipolar or unipolar depressed patients, who had received ECT in the 5 years prior to their death. They were compared to age-matched patients with a depressive disorder who had not received ECT and to matched healthy controls. Upon histopathological examination, no indications were observed for major hippocampal cell loss, overt cytoarchitectural changes or classic neuropathology in these 3 groups, nor were obvious differences present in inflammatory markers for astrocytes or microglia. Whereas the numbers of proliferating cells expressing Ki-67 was not different, we found a significantly higher percentage of cells positive for Doublecortin, a marker commonly used for young neurons and cellular plasticity, in the subgranular zone and CA4 / hilus of the hippocampus of ECT patients. Also, the percentage of positive Stathmin 1 cells was significantly higher in the subgranular zone of ECT patients, indicating neuroplasticity. These first post-mortem observations suggest that ECT has no damaging effects but may rather have induced neuroplasticity in the DG of depressed patients.
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Affiliation(s)
- Dore Loef
- Amsterdam UMC, location VUmc, Amsterdam, Department of Psychiatry, Amsterdam Neuroscience, Amsterdam, the Netherlands.
- GGZ inGeest Specialized Mental Health Care, Amsterdam, the Netherlands.
| | - Indira Tendolkar
- Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behavior, Centre for Cognitive Neuroimaging, Nijmegen, the Netherlands
- Department of Psychiatry and Psychotherapy, University Hospital Essen, Essen, Germany
| | - Philip F P van Eijndhoven
- Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands
- Donders Institute for Brain, Cognition and Behavior, Centre for Cognitive Neuroimaging, Nijmegen, the Netherlands
| | - Jeroen J M Hoozemans
- Department of Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Mardien L Oudega
- Amsterdam UMC, location VUmc, Amsterdam, Department of Psychiatry, Amsterdam Neuroscience, Amsterdam, the Netherlands
- GGZ inGeest Specialized Mental Health Care, Amsterdam, the Netherlands
| | - Annemieke J M Rozemuller
- Department of Pathology, Amsterdam Neuroscience, Amsterdam University Medical Centre, Amsterdam, the Netherlands
| | - Paul J Lucassen
- Brain Plasticity Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, the Netherlands
| | - Annemiek Dols
- Amsterdam UMC, location VUmc, Amsterdam, Department of Psychiatry, Amsterdam Neuroscience, Amsterdam, the Netherlands
- Department of Psychiatry, UMC Utrecht Brain Center, University Utrecht, Utrecht, the Netherlands
| | - Anke A Dijkstra
- Molecular Neuroscience Group, Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, the Netherlands
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7
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Bonfanti L, La Rosa C, Ghibaudi M, Sherwood CC. Adult neurogenesis and "immature" neurons in mammals: an evolutionary trade-off in plasticity? Brain Struct Funct 2023:10.1007/s00429-023-02717-9. [PMID: 37833544 DOI: 10.1007/s00429-023-02717-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 09/26/2023] [Indexed: 10/15/2023]
Abstract
Neuronal plasticity can vary remarkably in its form and degree across animal species. Adult neurogenesis, namely the capacity to produce new neurons from neural stem cells through adulthood, appears widespread in non-mammalian vertebrates, whereas it is reduced in mammals. A growing body of comparative studies also report variation in the occurrence and activity of neural stem cell niches between mammals, with a general trend of reduction from small-brained to large-brained species. Conversely, recent studies have shown that large-brained mammals host large amounts of neurons expressing typical markers of neurogenesis in the absence of cell division. In layer II of the cerebral cortex, populations of prenatally generated, non-dividing neurons continue to express molecules indicative of immaturity throughout life (cortical immature neurons; cINs). After remaining in a dormant state for a very long time, these cINs retain the potential of differentiating into mature neurons that integrate within the preexisting neural circuits. They are restricted to the paleocortex in small-brained rodents, while extending into the widely expanded neocortex of highly gyrencephalic, large-brained species. The current hypothesis is that these populations of non-newly generated "immature" neurons might represent a reservoir of developmentally plastic cells for mammalian species that are characterized by reduced stem cell-driven adult neurogenesis. This indicates that there may be a trade-off between various forms of plasticity that coexist during brain evolution. This balance may be necessary to maintain a "reservoir of plasticity" in brain regions that have distinct roles in species-specific socioecological adaptations, such as the neocortex and olfactory structures.
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Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy.
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095, Turin, Grugliasco, Italy.
| | - Chiara La Rosa
- Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy
| | - Marco Ghibaudi
- Neuroscience Institute Cavalieri Ottolenghi, Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, Largo Braccini 2, 10095, Turin, Grugliasco, Italy
| | - Chet C Sherwood
- Department of Anthropology and Center for the Advanced Study of Human Paleobiology, The George Washington University, Washington, DC, USA.
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8
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Li YN, Hu DD, Cai XL, Wang Y, Yang C, Jiang J, Zhang QL, Tu T, Wang XS, Wang H, Tu E, Wang XP, Pan A, Yan XX, Wan L. Doublecortin-Expressing Neurons in Human Cerebral Cortex Layer II and Amygdala from Infancy to 100 Years Old. Mol Neurobiol 2023; 60:3464-3485. [PMID: 36879137 DOI: 10.1007/s12035-023-03261-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 02/04/2023] [Indexed: 03/08/2023]
Abstract
A cohort of morphologically heterogenous doublecortin immunoreactive (DCX +) "immature neurons" has been identified in the cerebral cortex largely around layer II and the amygdala largely in the paralaminar nucleus (PLN) among various mammals. To gain a wide spatiotemporal view on these neurons in humans, we examined layer II and amygdalar DCX + neurons in the brains of infants to 100-year-old individuals. Layer II DCX + neurons occurred throughout the cerebrum in the infants/toddlers, mainly in the temporal lobe in the adolescents and adults, and only in the temporal cortex surrounding the amygdala in the elderly. Amygdalar DCX + neurons occurred in all age groups, localized primarily to the PLN, and reduced in number with age. The small-sized DCX + neurons were unipolar or bipolar, and formed migratory chains extending tangentially, obliquely, and inwardly in layers I-III in the cortex, and from the PLN to other nuclei in the amygdala. Morphologically mature-looking neurons had a relatively larger soma and weaker DCX reactivity. In contrast to the above, DCX + neurons in the hippocampal dentate gyrus were only detected in the infant cases in parallelly processed cerebral sections. The present study reveals a broader regional distribution of the cortical layer II DCX + neurons than previously documented in human cerebrum, especially during childhood and adolescence, while both layer II and amygdalar DCX + neurons persist in the temporal lobe lifelong. Layer II and amygdalar DCX + neurons may serve as an essential immature neuronal system to support functional network plasticity in human cerebrum in an age/region-dependent manner.
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Affiliation(s)
- Ya-Nan Li
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Dan-Dan Hu
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Xiao-Lu Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Yan Wang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Chen Yang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Juan Jiang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Qi-Lei Zhang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Tian Tu
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China.,Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Xiao-Sheng Wang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Hui Wang
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Ewen Tu
- Department of Neurology, Brain Hospital of Hunan Province, Changsha, 410007, Hunan, China
| | - Xiao-Ping Wang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, 410031, Hunan, China
| | - Aihua Pan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China.
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China
| | - Lily Wan
- Department of Anatomy and Neurobiology, Central South University Xiangya Medical School, Changsha, 410013, Hunan, China.
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9
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Ghibaudi M, Amenta A, Agosti M, Riva M, Graïc JM, Bifari F, Bonfanti L. Consistency and Variation in Doublecortin and Ki67 Antigen Detection in the Brain Tissue of Different Mammals, including Humans. Int J Mol Sci 2023; 24:2514. [PMID: 36768845 PMCID: PMC9916846 DOI: 10.3390/ijms24032514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/31/2023] Open
Abstract
Recently, a population of "immature" neurons generated prenatally, retaining immaturity for long periods and finally integrating in adult circuits has been described in the cerebral cortex. Moreover, comparative studies revealed differences in occurrence/rate of different forms of neurogenic plasticity across mammals, the "immature" neurons prevailing in gyrencephalic species. To extend experimentation from laboratory mice to large-brained mammals, including humans, it is important to detect cell markers of neurogenic plasticity in brain tissues obtained from different procedures (e.g., post-mortem/intraoperative specimens vs. intracardiac perfusion). This variability overlaps with species-specific differences in antigen distribution or antibody species specificity, making it difficult for proper comparison. In this work, we detect the presence of doublecortin and Ki67 antigen, markers for neuronal immaturity and cell division, in six mammals characterized by widely different brain size. We tested seven commercial antibodies in four selected brain regions known to host immature neurons (paleocortex, neocortex) and newly born neurons (hippocampus, subventricular zone). In selected human brains, we confirmed the specificity of DCX antibody by performing co-staining with fluorescent probe for DCX mRNA. Our results indicate that, in spite of various types of fixations, most differences were due to the use of different antibodies and the existence of real interspecies variation.
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Affiliation(s)
- Marco Ghibaudi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, 10095 Torino, Italy
| | - Alessia Amenta
- Laboratory of Cell Metabolism and Regenerative Medicine, Department of Medical Biotechnology and Translational Medicine, University of Milan, 20133 Milan, Italy
| | - Miriam Agosti
- Laboratory of Cell Metabolism and Regenerative Medicine, Department of Medical Biotechnology and Translational Medicine, University of Milan, 20133 Milan, Italy
| | - Marco Riva
- Department of Biomedical Sciences, Humanitas University, 20090 Pieve Emanuele, Italy
- IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy
| | - Jean-Marie Graïc
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020 Legnaro, Italy
| | - Francesco Bifari
- Laboratory of Cell Metabolism and Regenerative Medicine, Department of Medical Biotechnology and Translational Medicine, University of Milan, 20133 Milan, Italy
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, 10095 Torino, Italy
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10
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Immature excitatory neurons in the amygdala come of age during puberty. Dev Cogn Neurosci 2022; 56:101133. [PMID: 35841648 PMCID: PMC9289873 DOI: 10.1016/j.dcn.2022.101133] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/23/2022] [Accepted: 07/08/2022] [Indexed: 11/21/2022] Open
Abstract
The human amygdala is critical for emotional learning, valence coding, and complex social interactions, all of which mature throughout childhood, puberty, and adolescence. Across these ages, the amygdala paralaminar nucleus (PL) undergoes significant structural changes including increased numbers of mature neurons. The PL contains a large population of immature excitatory neurons at birth, some of which may continue to be born from local progenitors. These progenitors disappear rapidly in infancy, but the immature neurons persist throughout childhood and adolescent ages, indicating that they develop on a protracted timeline. Many of these late-maturing neurons settle locally within the PL, though a small subset appear to migrate into neighboring amygdala subnuclei. Despite its prominent growth during postnatal life and possible contributions to multiple amygdala circuits, the function of the PL remains unknown. PL maturation occurs predominately during late childhood and into puberty when sex hormone levels change. Sex hormones can promote developmental processes such as neuron migration, dendritic outgrowth, and synaptic plasticity, which appear to be ongoing in late-maturing PL neurons. Collectively, we describe how the growth of late-maturing neurons occurs in the right time and place to be relevant for amygdala functions and neuropsychiatric conditions.
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11
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Ghibaudi M, Bonfanti L. How Widespread Are the “Young” Neurons of the Mammalian Brain? Front Neurosci 2022; 16:918616. [PMID: 35733930 PMCID: PMC9207312 DOI: 10.3389/fnins.2022.918616] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/17/2022] [Indexed: 12/14/2022] Open
Abstract
After the discovery of adult neurogenesis (stem cell-driven production of new neuronal elements), it is conceivable to find young, undifferentiated neurons mixed with mature neurons in the neural networks of the adult mammalian brain. This “canonical” neurogenesis is restricted to small stem cell niches persisting from embryonic germinal layers, yet, the genesis of new neurons has also been reported in various parenchymal brain regions. Whichever the process involved, several populations of “young” neurons can be found at different locations of the brain. Across the years, further complexity emerged: (i) molecules of immaturity can also be expressed by non-dividing cells born during embryogenesis, then maintaining immature features later on; (ii) remarkable interspecies differences exist concerning the types, location, amount of undifferentiated neurons; (iii) re-expression of immaturity can occur in aging (dematuration). These twists are introducing a somewhat different definition of neurogenesis than normally assumed, in which our knowledge of the “young” neurons is less sharp. In this emerging complexity, there is a need for complete mapping of the different “types” of young neurons, considering their role in postnatal development, plasticity, functioning, and interspecies differences. Several important aspects are at stake: the possible role(s) that the young neurons may play in maintaining brain efficiency and in prevention/repair of neurological disorders; nonetheless, the correct translation of results obtained from laboratory rodents. Hence, the open question is: how many types of undifferentiated neurons do exist in the brain, and how widespread are they?
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Affiliation(s)
- Marco Ghibaudi
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
- *Correspondence: Luca Bonfanti,
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12
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Roeder SS, Burkardt P, Rost F, Rode J, Brusch L, Coras R, Englund E, Håkansson K, Possnert G, Salehpour M, Primetzhofer D, Csiba L, Molnár S, Méhes G, Tonchev AB, Schwab S, Bergmann O, Huttner HB. Evidence for postnatal neurogenesis in the human amygdala. Commun Biol 2022; 5:366. [PMID: 35440676 PMCID: PMC9018740 DOI: 10.1038/s42003-022-03299-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 03/22/2022] [Indexed: 12/12/2022] Open
Abstract
The human amygdala is involved in processing of memory, decision-making, and emotional responses. Previous studies suggested that the amygdala may represent a neurogenic niche in mammals. By combining two distinct methodological approaches, lipofuscin quantification and 14C-based retrospective birth dating of neurons, along with mathematical modelling, we here explored whether postnatal neurogenesis exists in the human amygdala. We investigated post-mortem samples of twelve neurologically healthy subjects. The average rate of lipofuscin-negative neurons was 3.4%, representing a substantial proportion of cells substantially younger than the individual. Mass spectrometry analysis of genomic 14C-concentrations in amygdala neurons compared with atmospheric 14C-levels provided evidence for postnatal neuronal exchange. Mathematical modelling identified a best-fitting scenario comprising of a quiescent and a renewing neuronal population with an overall renewal rate of >2.7% per year. In conclusion, we provide evidence for postnatal neurogenesis in the human amygdala with cell turnover rates comparable to the hippocampus. Lipofuscin labeling and 14 C retrospective birth-dating of neurons, along with mathematical modelling, here suggest continued postnatal neurogenesis in the human amygdala, rather than protracted maturation of developmentally generated neurons.
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Affiliation(s)
- Sebastian S Roeder
- Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Petra Burkardt
- Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Fabian Rost
- Center for Regenerative Therapies (CRTD), TU Dresden, Dresden, Germany.,Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.,Center for Information Services and High Performance Computing (ZIH), TU Dresden, Dresden, Germany.,Center for Molecular and Cellular Bioengineering, DRESDEN-concept Genome Center, TU Dresden, Dresden, Germany
| | - Julian Rode
- Center for Information Services and High Performance Computing (ZIH), TU Dresden, Dresden, Germany
| | - Lutz Brusch
- Center for Information Services and High Performance Computing (ZIH), TU Dresden, Dresden, Germany
| | - Roland Coras
- Department of Neuropathology, University of Erlangen-Nuremberg, Erlangen, Germany
| | | | - Karl Håkansson
- Tandem Laboratory, Uppsala University, Uppsala, Sweden.,Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | | | - Mehran Salehpour
- Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | - Daniel Primetzhofer
- Tandem Laboratory, Uppsala University, Uppsala, Sweden.,Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
| | - László Csiba
- Department of Neurology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,MTA-DE Cerebrovascular and Neurodegenerative Research Group, Debrecen, Hungary
| | - Sarolta Molnár
- Department of Pathology, University of Debrecen, Debrecen, Hungary
| | - Gábor Méhes
- Department of Pathology, University of Debrecen, Debrecen, Hungary
| | - Anton B Tonchev
- Departments of Anatomy, Cell Biology and Stem Cell Biology, Medical University Varna, Varna, Bulgaria
| | - Stefan Schwab
- Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Olaf Bergmann
- Center for Regenerative Therapies (CRTD), TU Dresden, Dresden, Germany.,Department of Cell and Molecular Biology, Karolinska Institute, Stockholm, Sweden
| | - Hagen B Huttner
- Department of Neurology, University of Erlangen-Nuremberg, Erlangen, Germany. .,Department of Neurology, Justus Liebig University Giessen, Giessen, Germany.
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13
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Coviello S, Gramuntell Y, Klimczak P, Varea E, Blasco-Ibañez JM, Crespo C, Gutierrez A, Nacher J. Phenotype and Distribution of Immature Neurons in the Human Cerebral Cortex Layer II. Front Neuroanat 2022; 16:851432. [PMID: 35464133 PMCID: PMC9027810 DOI: 10.3389/fnana.2022.851432] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
This work provides evidence of the presence of immature neurons in the human brain, specifically in the layer II of the cerebral cortex. Using surgical samples from epileptic patients and post-mortem tissue, we have found cells with different levels of dendritic complexity (type I and type II cells) expressing DCX and PSA-NCAM and lacking expression of the mature neuronal marker NeuN. These immature cells belonged to the excitatory lineage, as demonstrated both by the expression of CUX1, CTIP2, and TBR1 transcription factors and by the lack of the inhibitory marker GAD67. The type II cells had some puncta expressing inhibitory and excitatory synaptic markers apposed to their perisomatic and peridendritic regions and ultrastructural analysis suggest the presence of synaptic contacts. These cells did not present glial cell markers, although astroglial and microglial processes were found in close apposition to their somata and dendrites, particularly on type I cells. Our findings confirm the presence of immature neurons in several regions of the cerebral cortex of humans of different ages and define their lineage. The presence of some mature features in some of these cells suggests the possibility of a progressively integration as excitatory neurons, as described in the olfactory cortex of rodents.
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Affiliation(s)
- Simona Coviello
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Yaiza Gramuntell
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Patrycja Klimczak
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
- Spanish National Network for Research in Mental Health, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
| | - Emilio Varea
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - José Miguel Blasco-Ibañez
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Carlos Crespo
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Antonio Gutierrez
- Unidad de Cirugía de la Epilepsia, Hospital Universitario La Fe, Valencia, Spain
| | - Juan Nacher
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
- Spanish National Network for Research in Mental Health, Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid, Spain
- Fundación Investigación Hospital Clínico de Valencia (INCLIVA), Valencia, Spain
- *Correspondence: Juan Nacher,
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14
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Ai JQ, Luo R, Tu T, Yang C, Jiang J, Zhang B, Bi R, Tu E, Yao YG, Yan XX. Doublecortin-Expressing Neurons in Chinese Tree Shrew Forebrain Exhibit Mixed Rodent and Primate-Like Topographic Characteristics. Front Neuroanat 2021; 15:727883. [PMID: 34602987 PMCID: PMC8481370 DOI: 10.3389/fnana.2021.727883] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Accepted: 08/23/2021] [Indexed: 11/18/2022] Open
Abstract
Doublecortin (DCX) is transiently expressed in new-born neurons in the subventricular zone (SVZ) and subgranular zone (SGZ) related to adult neurogenesis in the olfactory bulb (OB) and hippocampal formation. DCX immunoreactive (DCX+) immature neurons also occur in the cerebral cortex primarily over layer II and the amygdala around the paralaminar nucleus (PLN) in various mammals, with interspecies differences pointing to phylogenic variation. The tree shrews (Tupaia belangeri) are phylogenetically closer to primates than to rodents. Little is known about DCX+ neurons in the brain of this species. In the present study, we characterized DCX immunoreactivity (IR) in the forebrain of Chinese tree shrews aged from 2 months- to 6 years-old (n = 18). DCX+ cells were present in the OB, SVZ, SGZ, the piriform cortex over layer II, and the amygdala around the PLN. The numerical densities of DCX+ neurons were reduced in all above neuroanatomical regions with age, particularly dramatic in the DG in the 5–6 years-old animals. Thus, DCX+ neurons are present in the two established neurogenic sites (SVZ and SGZ) in the Chinese tree shrew as seen in other mammals. DCX+ cortical neurons in this animal exhibit a topographic pattern comparable to that in mice and rats, while these immature neurons are also present in the amygdala, concentrating around the PLN as seen in primates and some nonprimate mammals.
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Affiliation(s)
- Jia-Qi Ai
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Rongcan Luo
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Tian Tu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Chen Yang
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Juan Jiang
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
| | - Bo Zhang
- Department of Neurology, Brain Hospital of Hunan Province, Changsha, China
| | - Rui Bi
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Ewen Tu
- Department of Neurology, Brain Hospital of Hunan Province, Changsha, China
| | - Yong-Gang Yao
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunan Province, and KIZ/CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China.,Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, China.,CSA Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, China
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15
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Bonfanti L, Seki T. The PSA-NCAM-Positive "Immature" Neurons: An Old Discovery Providing New Vistas on Brain Structural Plasticity. Cells 2021; 10:2542. [PMID: 34685522 PMCID: PMC8534119 DOI: 10.3390/cells10102542] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/14/2021] [Accepted: 09/24/2021] [Indexed: 01/18/2023] Open
Abstract
Studies on brain plasticity have undertaken different roads, tackling a wide range of biological processes: from small synaptic changes affecting the contacts among neurons at the very tip of their processes, to birth, differentiation, and integration of new neurons (adult neurogenesis). Stem cell-driven adult neurogenesis is an exception in the substantially static mammalian brain, yet, it has dominated the research in neurodevelopmental biology during the last thirty years. Studies of comparative neuroplasticity have revealed that neurogenic processes are reduced in large-brained mammals, including humans. On the other hand, large-brained mammals, with respect to rodents, host large populations of special "immature" neurons that are generated prenatally but express immature markers in adulthood. The history of these "immature" neurons started from studies on adhesion molecules carried out at the beginning of the nineties. The identity of these neurons as "stand by" cells "frozen" in a state of immaturity remained un-detected for long time, because of their ill-defined features and because clouded by research ef-forts focused on adult neurogenesis. In this review article, the history of these cells will be reconstructed, and a series of nuances and confounding factors that have hindered the distinction between newly generated and "immature" neurons will be addressed.
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Affiliation(s)
- Luca Bonfanti
- Neuroscience Institute Cavalieri Ottolenghi (NICO), 10043 Orbassano, Italy
- Department of Veterinary Sciences, University of Turin, 10095 Torino, Italy
| | - Tatsunori Seki
- Department of Histology and Neuroanatomy, Tokyo Medical University, Tokyo 160-8402, Japan
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 160-8402, Japan
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16
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Implications of Extended Inhibitory Neuron Development. Int J Mol Sci 2021; 22:ijms22105113. [PMID: 34066025 PMCID: PMC8150951 DOI: 10.3390/ijms22105113] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 12/23/2022] Open
Abstract
A prolonged developmental timeline for GABA (γ-aminobutyric acid)-expressing inhibitory neurons (GABAergic interneurons) is an amplified trait in larger, gyrencephalic animals. In several species, the generation, migration, and maturation of interneurons take place over several months, in some cases persisting after birth. The late integration of GABAergic interneurons occurs in a region-specific pattern, especially during the early postnatal period. These changes can contribute to the formation of functional connectivity and plasticity, especially in the cortical regions responsible for higher cognitive tasks. In this review, we discuss GABAergic interneuron development in the late gestational and postnatal forebrain. We propose the protracted development of interneurons at each stage (neurogenesis, neuronal migration, and network integration), as a mechanism for increased complexity and cognitive flexibility in larger, gyrencephalic brains. This developmental feature of interneurons also provides an avenue for environmental influences to shape neural circuit formation.
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17
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Sorrells SF, Paredes MF, Zhang Z, Kang G, Pastor-Alonso O, Biagiotti S, Page CE, Sandoval K, Knox A, Connolly A, Huang EJ, Garcia-Verdugo JM, Oldham MC, Yang Z, Alvarez-Buylla A. Positive Controls in Adults and Children Support That Very Few, If Any, New Neurons Are Born in the Adult Human Hippocampus. J Neurosci 2021; 41:2554-2565. [PMID: 33762407 PMCID: PMC8018729 DOI: 10.1523/jneurosci.0676-20.2020] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 01/19/2023] Open
Abstract
Adult hippocampal neurogenesis was originally discovered in rodents. Subsequent studies identified the adult neural stem cells and found important links between adult neurogenesis and plasticity, behavior, and disease. However, whether new neurons are produced in the human dentate gyrus (DG) during healthy aging is still debated. We and others readily observe proliferating neural progenitors in the infant hippocampus near immature cells expressing doublecortin (DCX), but the number of such cells decreases in children and few, if any, are present in adults. Recent investigations using dual antigen retrieval find many cells stained by DCX antibodies in adult human DG. This has been interpreted as evidence for high rates of adult neurogenesis, even at older ages. However, most of these DCX-labeled cells have mature morphology. Furthermore, studies in the adult human DG have not found a germinal region containing dividing progenitor cells. In this Dual Perspectives article, we show that dual antigen retrieval is not required for the detection of DCX in multiple human brain regions of infants or adults. We review prior studies and present new data showing that DCX is not uniquely expressed by newly born neurons: DCX is present in adult amygdala, entorhinal and parahippocampal cortex neurons despite being absent in the neighboring DG. Analysis of available RNA-sequencing datasets supports the view that DG neurogenesis is rare or absent in the adult human brain. To resolve the conflicting interpretations in humans, it is necessary to identify and visualize dividing neuronal precursors or develop new methods to evaluate the age of a neuron at the single-cell level.
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Affiliation(s)
- Shawn F Sorrells
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Mercedes F Paredes
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
| | - Zhuangzhi Zhang
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai, P.R. 200032 China
| | - Gugene Kang
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California 94143
| | - Oier Pastor-Alonso
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
| | - Sean Biagiotti
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Chloe E Page
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Kadellyn Sandoval
- Department of Neurology, University of California San Francisco, San Francisco, California 94143
| | - Anthony Knox
- Department of Pathology, University of California San Francisco, San Francisco, California 94143
| | - Andrew Connolly
- Department of Pathology, University of California San Francisco, San Francisco, California 94143
| | - Eric J Huang
- Department of Pathology, University of California San Francisco, San Francisco, California 94143
| | - Jose Manuel Garcia-Verdugo
- Laboratorio de Neurobiología Comparada, Instituto Cavanilles, Universidad de Valencia, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas, Valencia 46980, Spain
| | - Michael C Oldham
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California 94143
| | - Zhengang Yang
- State Key Laboratory of Medical Neurobiology and Institutes of Brain Science, Fudan University, Shanghai, P.R. 200032 China
| | - Arturo Alvarez-Buylla
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California San Francisco, San Francisco, California 94143
- Department of Neurological Surgery, University of California San Francisco, San Francisco, California 94143
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18
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Sharif A, Fitzsimons CP, Lucassen PJ. Neurogenesis in the adult hypothalamus: A distinct form of structural plasticity involved in metabolic and circadian regulation, with potential relevance for human pathophysiology. HANDBOOK OF CLINICAL NEUROLOGY 2021; 179:125-140. [PMID: 34225958 DOI: 10.1016/b978-0-12-819975-6.00006-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The adult brain harbors specific niches where stem cells undergo substantial plasticity and, in some regions, generate new neurons throughout life. This phenomenon is well known in the subventricular zone of the lateral ventricles and the subgranular zone of the hippocampus and has recently also been described in the hypothalamus of several rodent and primate species. After a brief overview of preclinical studies illustrating the pathophysiologic significance of hypothalamic neurogenesis in the control of energy metabolism, reproduction, thermoregulation, sleep, and aging, we review current literature on the neurogenic niche of the human hypothalamus. A comparison of the organization of the niche between humans and rodents highlights some common features, but also substantial differences, e.g., in the distribution and extent of the hypothalamic neural stem cells. Exploring the full dynamics of hypothalamic neurogenesis in humans raises a formidable challenge however, given among others, inherent technical limitations. We close with discussing possible functional role(s) of the human hypothalamic niche, and how gaining more insights into this form of plasticity could be relevant for a better understanding of pathologies associated with disturbed hypothalamic function.
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Affiliation(s)
- Ariane Sharif
- Lille Neuroscience & Cognition, University of Lille, Lille, France.
| | - Carlos P Fitzsimons
- Brain Plasticity Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Paul J Lucassen
- Brain Plasticity Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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19
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Coviello S, Gramuntell Y, Castillo-Gomez E, Nacher J. Effects of Dopamine on the Immature Neurons of the Adult Rat Piriform Cortex. Front Neurosci 2020; 14:574234. [PMID: 33122993 PMCID: PMC7573248 DOI: 10.3389/fnins.2020.574234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 09/14/2020] [Indexed: 11/26/2022] Open
Abstract
The layer II of the adult piriform cortex (PCX) contains a numerous population of immature neurons. Interestingly, in both mice and rats, most, if not all, these cells have an embryonic origin. Moreover, recent studies from our laboratory have shown that they progressively mature into typical excitatory neurons of the PCX layer II. Therefore, the adult PCX is considered a “non-canonical” neurogenic niche. These immature neurons express the polysialylated form of the neural cell adhesion molecule (PSA-NCAM), a molecule critical for different neurodevelopmental processes. Dopamine (DA) is a relevant neurotransmitter in the adult CNS, which also plays important roles in neural development and adult plasticity, including the regulation of PSA-NCAM expression. In order to evaluate the hypothetical effects of pharmacological modulation of dopaminergic neurotransmission on the differentiation of immature neurons of the adult PCX, we studied dopamine D2 receptor (D2r) expression in this region and the relationship between dopaminergic fibers and immature neurons (defined by PSA-NCAM expression). In addition, we analyzed the density of immature neurons after chronic treatments with an antagonist and an agonist of D2r: haloperidol and PPHT, respectively. Many dopaminergic fibers were observed in close apposition to PSA-NCAM-expressing neurons, which also coexpressed D2r. Chronic treatment with haloperidol significantly increased the number of PSA-NCAM immunoreactive cells, while PPHT treatment decreased it. These results indicate a prominent role of dopamine, through D2r and PSA-NCAM, on the regulation of the final steps of development of immature neurons in the adult PCX.
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Affiliation(s)
- Simona Coviello
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Yaiza Gramuntell
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain
| | - Esther Castillo-Gomez
- Department of Medicine, School of Medical Sciences, Universitat Jaume I, Castellón de la Plana, Spain.,Spanish National Network for Research in Mental Health (CIBERSAM), Madrid, Spain
| | - Juan Nacher
- Neurobiology Unit, Program in Neurosciences and Institute of Biotechnology and Biomedicine (BIOTECMED), Universitat de València, Burjassot, Spain.,Spanish National Network for Research in Mental Health (CIBERSAM), Madrid, Spain.,Fundación Investigación Hospital Clínico de Valencia, INCLIVA, Valencia, Spain
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20
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Amygdala GluN2B-NMDAR dysfunction is critical in abnormal aggression of neurodevelopmental origin induced by St8sia2 deficiency. Mol Psychiatry 2020; 25:2144-2161. [PMID: 30089788 PMCID: PMC7473847 DOI: 10.1038/s41380-018-0132-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/02/2018] [Accepted: 06/28/2018] [Indexed: 11/23/2022]
Abstract
Aggression is frequently observed in neurodevelopmental psychiatric disorders such as schizophrenia, autism, and bipolar disorder. Due to a lack of understanding of its underlying mechanisms, effective treatments for abnormal aggression are still missing. Recently, genetic variations in Sialyltransferase 2 (St8sia2) have been linked to these disorders and aggression. Here we identify abnormal aggressive behaviors and concomitant blunted fear learning in St8sia2 knockout (-/-) mice. It is worth noting that the amygdala of St8sia2-/- mice shows diminished threat-induced activation, as well as alterations in synaptic structure and function, including impaired GluN2B-containing NMDA receptor-mediated synaptic transmission and plasticity. Pharmacological rescue of NMDA receptor activity in the amygdala of St8sia2-/- mice with the partial agonist D-cycloserine restores synaptic plasticity and normalizes behavioral aberrations. Pathological aggression and associated traits were recapitulated by specific amygdala neonatal St8sia2 silencing. Our results establish a developmental link between St8sia2 deficiency and a pathological aggression syndrome, specify synaptic targets for therapeutic developments, and highlight D-cycloserine as a plausible treatment.
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21
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Sorrells SF, Paredes MF, Velmeshev D, Herranz-Pérez V, Sandoval K, Mayer S, Chang EF, Insausti R, Kriegstein AR, Rubenstein JL, Manuel Garcia-Verdugo J, Huang EJ, Alvarez-Buylla A. Immature excitatory neurons develop during adolescence in the human amygdala. Nat Commun 2019; 10:2748. [PMID: 31227709 PMCID: PMC6588589 DOI: 10.1038/s41467-019-10765-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 04/18/2019] [Indexed: 02/07/2023] Open
Abstract
The human amygdala grows during childhood, and its abnormal development is linked to mood disorders. The primate amygdala contains a large population of immature neurons in the paralaminar nuclei (PL), suggesting protracted development and possibly neurogenesis. Here we studied human PL development from embryonic stages to adulthood. The PL develops next to the caudal ganglionic eminence, which generates inhibitory interneurons, yet most PL neurons express excitatory markers. In children, most PL cells are immature (DCX+PSA-NCAM+), and during adolescence many transition into mature (TBR1+VGLUT2+) neurons. Immature PL neurons persist into old age, yet local progenitor proliferation sharply decreases in infants. Using single nuclei RNA sequencing, we identify the transcriptional profile of immature excitatory neurons in the human amygdala between 4-15 years. We conclude that the human PL contains excitatory neurons that remain immature for decades, a possible substrate for persistent plasticity at the interface of the hippocampus and amygdala.
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Affiliation(s)
- Shawn F Sorrells
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Mercedes F Paredes
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Dmitry Velmeshev
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Vicente Herranz-Pérez
- Laboratory of Comparative Neurobiology, Institute Cavanilles, University of Valencia, CIBERNED, 46980, Valencia, Spain
- Predepartamental Unit of Medicine, Faculty of Health Sciences, Universitat Jaume I, 12071, Castelló de la Plana, Spain
| | - Kadellyn Sandoval
- Department of Neurology, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Simone Mayer
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Edward F Chang
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Ricardo Insausti
- Human Neuroanatomy Laboratory, School of Medicine and CRIB, University of Castilla-La Mancha, 02006, Albacete, Spain
| | - Arnold R Kriegstein
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - John L Rubenstein
- Department of Psychiatry, Rock Hall, University of California, San Francisco, San Francisco, CA, 94158-2324, USA
| | - Jose Manuel Garcia-Verdugo
- Laboratory of Comparative Neurobiology, Institute Cavanilles, University of Valencia, CIBERNED, 46980, Valencia, Spain
| | - Eric J Huang
- Department of Pathology, University of California, San Francisco, San Francisco, CA, 94143, USA
| | - Arturo Alvarez-Buylla
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA.
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, 94143, USA.
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Pregnancy Promotes Maternal Hippocampal Neurogenesis in Guinea Pigs. Neural Plast 2019; 2019:5765284. [PMID: 31097956 PMCID: PMC6487096 DOI: 10.1155/2019/5765284] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/08/2019] [Accepted: 02/21/2019] [Indexed: 11/26/2022] Open
Abstract
Adult neurogenesis in the hippocampal dentate gyrus (DG) modulates cognition and behavior in mammals, while motherhood is associated with cognitive and behavioral changes essential for the care of the young. In mice and rats, hippocampal neurogenesis is reported to be reduced or unchanged during pregnancy, with few data available from other species. In guinea pigs, pregnancy lasts ~9 weeks; we set to explore if hippocampal neurogenesis is altered in these animals, relative to gestational stages. Time-pregnant primigravidas (3-5 months old) and age-matched nonpregnant females were examined, with neurogenic potential evaluated via immunolabeling of Ki67, Sp8, doublecortin (DCX), and neuron-specific nuclear antigen (NeuN) combined with bromodeoxyuridine (BrdU) birth-dating. Relative to control, subgranular Ki67, Sp8, and DCX-immunoreactive (+) cells tended to increase from early gestation to postpartum and peaked at the late gestational stage. In BrdU pulse-chasing experiments in nonpregnant females surviving for different time points (2-120 days), BrdU+ cells in the DG colocalized with DCX partially from 2 to 42 days (most frequently at 14-30 days) and with NeuN increasingly from 14 to 120 days. In pregnant females that received BrdU at early, middle, and late gestational stages and survived for 42 days, the density of BrdU+ cells in the DG was mostly high in the late gestational group. The rates of BrdU/DCX and BrdU/NeuN colocalization were similar among these groups and comparable to those among the corresponding control group. Together, the findings suggest that pregnancy promotes maternal hippocampal neurogenesis in guinea pigs, at least among primigravidas.
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Gatt A, Lee H, Williams G, Thuret S, Ballard C. Expression of neurogenic markers in Alzheimer's disease: a systematic review and metatranscriptional analysis. Neurobiol Aging 2019; 76:166-180. [PMID: 30716542 DOI: 10.1016/j.neurobiolaging.2018.12.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 12/20/2018] [Accepted: 12/27/2018] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia characterized by substantial neuronal loss and progressive brain atrophy. Animal studies have suggested that the process of adult neurogenesis might be altered at the earliest phases of disease onset. The relationship between AD progression and adult neurogenesis in the human brain is, however, not well understood. Here, we present a systematic review of the postmortem studies that investigated changes in human adult neurogenesis in the AD brain. We present findings from 11 postmortem studies that were identified by a systematic search within the literature, focusing on what markers of neurogenesis were used, which stages of AD were investigated, and whether the studies had any confounding information that could potentially hinder clear interpretation of the presented data. In addition, we also review studies that examined transcriptomic changes in human AD postmortem brains and reveal upregulated expression of neural progenitor and proliferation markers and downregulated expression of later neurogenic markers in AD. Taken together, the existing literature seems to suggest that the overall level of human adult neurogenesis is reduced during the later stages of AD, potentially due to failed maturation and integration of new-born neurons. Further investigations using complementary methods such as in vitro disease modeling will be helpful to understand the exact molecular mechanisms underlying such pattern of change and to determine whether neurogenesis can be an effective therapeutic target for early intervention.
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Affiliation(s)
- Ariana Gatt
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK.
| | - Hyunah Lee
- Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Gareth Williams
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Sandrine Thuret
- Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Clive Ballard
- Wolfson Centre for Age-Related Diseases, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK; Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
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24
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Liu JYW, Matarin M, Reeves C, McEvoy AW, Miserocchi A, Thompson P, Sisodiya SM, Thom M. Doublecortin-expressing cell types in temporal lobe epilepsy. Acta Neuropathol Commun 2018; 6:60. [PMID: 30005693 PMCID: PMC6045867 DOI: 10.1186/s40478-018-0566-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/03/2018] [Indexed: 12/14/2022] Open
Abstract
Doublecortin (DCX) is widely regarded as a marker of immature and migrating neurons during development. While DCX expression persists in adults, particularly in the temporal lobe and neurogenic regions, it is unknown how seizures influence its expression. The aim of the present study was to explore the distribution and characteristics of DCX-expressing cells in surgical and postmortem samples from 40 adult and paediatric patients, with epilepsy and with or without hippocampal sclerosis (HS), compared to post mortem controls. The hippocampus (pes and body), parahippocampal gyrus, amygdala, temporal pole and temporal cortex were examined with DCX immunohistochemistry using four commercially-available DCX antibodies, labelled cells were quantified in different regions of interest as well as their co-expression with cell type specific markers (CD68, Iba1, GFAP, GFAP∂, nestin, SOX2, CD34, OLIG2, PDGFRβ, NeuN) and cell cycle marker (MCM2). Histological findings were compared with clinical data, as well as gene expression data obtained from the temporal cortex of 83 temporal lobe epilepsy cases with HS. DCX immunohistochemistry identified immature (Nestin−/NeuN−) neurons in layer II of the temporal neocortex in patients with and without epilepsy. Their number declined significantly with age but was not associated with the presence of hippocampal sclerosis, seizure semiology or memory dysfunction. DCX+ cells were prominent in the paralaminar nuclei and periamygdalar cortex and these declined with age but were not significantly associated with epilepsy history. DCX expressing cells with ramified processes were prominent in all regions, particularly in the hippocampal subgranular zone, where significantly increased numbers were observed in epilepsy samples compared to controls. DCX ramified cells co-expressed Iba1, CD68 and PDGFRβ, and less frequently MCM2, OLIG2 and SOX2, but no co-localization was observed with CD34, nestin or GFAP/GFAP ∂. Gene expression data from neocortical samples in patients with TLE and HS supported ongoing DCX expression in adults. We conclude that DCX identifies a range of morphological cell types in temporal lobe epilepsy, including immature populations, glial and microglial cell types. Their clinical relevance and biological function requires further study but we show some evidence for alteration with age and in epilepsy.
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25
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Neuron numbers increase in the human amygdala from birth to adulthood, but not in autism. Proc Natl Acad Sci U S A 2018; 115:3710-3715. [PMID: 29559529 PMCID: PMC5889677 DOI: 10.1073/pnas.1801912115] [Citation(s) in RCA: 103] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Remarkably little is known about the postnatal cellular development of the human amygdala. It plays a central role in mediating emotional behavior and has an unusually protracted development well into adulthood, increasing in size by 40% from youth to adulthood. Variation from this typical neurodevelopmental trajectory could have profound implications on normal emotional development. We report the results of a stereological analysis of the number of neurons in amygdala nuclei of 52 human brains ranging from 2 to 48 years of age [24 neurotypical and 28 autism spectrum disorder (ASD)]. In neurotypical development, the number of mature neurons in the basal and accessory basal nuclei increases from childhood to adulthood, coinciding with a decrease of immature neurons within the paralaminar nucleus. Individuals with ASD, in contrast, show an initial excess of amygdala neurons during childhood, followed by a reduction in adulthood across nuclei. We propose that there is a long-term contribution of mature neurons from the paralaminar nucleus to other nuclei of the neurotypical human amygdala and that this growth trajectory may be altered in ASD, potentially underlying the volumetric changes detected in ASD and other neurodevelopmental or neuropsychiatric disorders.
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26
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Jhaveri DJ, Tedoldi A, Hunt S, Sullivan R, Watts NR, Power JM, Bartlett PF, Sah P. Evidence for newly generated interneurons in the basolateral amygdala of adult mice. Mol Psychiatry 2018; 23:521-532. [PMID: 28809399 PMCID: PMC5822453 DOI: 10.1038/mp.2017.134] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2015] [Revised: 05/02/2017] [Accepted: 05/08/2017] [Indexed: 11/27/2022]
Abstract
New neurons are continually generated from the resident populations of precursor cells in selective niches of the adult mammalian brain such as the hippocampal dentate gyrus and the olfactory bulb. However, whether such cells are present in the adult amygdala, and their neurogenic capacity, is not known. Using the neurosphere assay, we demonstrate that a small number of precursor cells, the majority of which express Achaete-scute complex homolog 1 (Ascl1), are present in the basolateral amygdala (BLA) of the adult mouse. Using neuron-specific Thy1-YFP transgenic mice, we show that YFP+ cells in BLA-derived neurospheres have a neuronal morphology, co-express the neuronal marker βIII-tubulin, and generate action potentials, confirming their neuronal phenotype. In vivo, we demonstrate the presence of newly generated BrdU-labeled cells in the adult BLA, and show that a proportion of these cells co-express the immature neuronal marker doublecortin (DCX). Furthermore, we reveal that a significant proportion of GFP+ neurons (~23%) in the BLA are newly generated (BrdU+) in DCX-GFP mice, and using whole-cell recordings in acute slices we demonstrate that the GFP+ cells display electrophysiological properties that are characteristic of interneurons. Using retrovirus-GFP labeling as well as the Ascl1CreERT2 mouse line, we further confirm that the precursor cells within the BLA give rise to mature and functional interneurons that persist in the BLA for at least 8 weeks after their birth. Contextual fear conditioning has no effect on the number of neurospheres or BrdU-labeled cells in the BLA, but produces an increase in hippocampal cell proliferation. These results demonstrate that neurogenic precursor cells are present in the adult BLA, and generate functional interneurons, but also show that their activity is not regulated by an amygdala-dependent learning paradigm.
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Affiliation(s)
- D J Jhaveri
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,Mater Research Institute, The University of Queensland, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
| | - A Tedoldi
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - S Hunt
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - R Sullivan
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia
| | - N R Watts
- Critical Care and Trauma Division, The George Institute for Global Health, Sydney, NSW, Australia
| | - J M Power
- School of Medical Science, University of New South Wales, Sydney, NSW, Australia
| | - P F Bartlett
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
| | - P Sah
- The University of Queensland, Queensland Brain Institute, Brisbane, QLD, Australia,The Queensland Brain Institute, University of Queensland, Hawken Drive, St Lucia, 4072 QLD, Australia. E-mail: or or
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27
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Distribution and fate of DCX/PSA-NCAM expressing cells in the adult mammalian cortex: A local reservoir for adult cortical neuroplasticity? ACTA ACUST UNITED AC 2016. [DOI: 10.1007/s11515-016-1403-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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28
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Peragine DE, Yousuf Y, Fu Y, Swift-Gallant A, Ginzberg K, Holmes MM. Contrasting effects of opposite- versus same-sex housing on hormones, behavior and neurogenesis in a eusocial mammal. Horm Behav 2016; 81:28-37. [PMID: 27018426 DOI: 10.1016/j.yhbeh.2016.03.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 02/29/2016] [Accepted: 03/18/2016] [Indexed: 12/22/2022]
Abstract
Competitive interactions can have striking and enduring effects on behavior, but the mechanisms underlying this experience-induced plasticity are unclear, particularly in females. Naked mole-rat (NMR) colonies are characterized by the strictest social and reproductive hierarchy among mammals, and represent an ideal system for studies of social competition. In large matriarchal colonies, breeding is monopolized by one female and 1-3 males, with other colony members being socially subordinate and reproductively suppressed. To date, competition for breeding status has been examined in-colony, with female, but not male, aggression observed following the death/removal of established queens. To determine whether this sex difference extends to colony-founding contexts, and clarify neural and endocrine mechanisms underlying behavioral change in females competing for status, we examined neurogenesis and steroid hormone concentrations in colony-housed subordinates, and NMRs given the opportunity to transition status via pair-housing. To this end, Ki-67 and doublecortin immunoreactivity were compared in the hippocampal dentate gyrus (DG) and basolateral amygdala (BLA) of colony-housed subordinates, and subordinates housed with a same-sex (SS) or opposite-sex (OS) conspecific. Results suggest that OS pairing in eusocial mammals promotes cooperation and enhances hippocampal plasticity, while SS pairing is stressful, resulting in enhanced HPA activation and muted hippocampal neurogenesis relative to OS pairs. Data further indicate that competition for status is confined to females, with female-female housing exerting contrasting effects on hippocampal and amygdalar neurogenesis. These findings advance understanding of social stress effects on neuroplasticity and behavior, and highlight the importance of including female-dominated species in research on aggression and intrasexual competition.
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Affiliation(s)
- Deane E Peragine
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Yusef Yousuf
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Yi Fu
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Ashlyn Swift-Gallant
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Keren Ginzberg
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada; Department of Cell & Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada; Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, ON, M5S 3G5, Canada.
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29
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Rubio A, Belles M, Belenguer G, Vidueira S, Fariñas I, Nacher J. Characterization and isolation of immature neurons of the adult mouse piriform cortex. Dev Neurobiol 2015; 76:748-63. [PMID: 26487449 DOI: 10.1002/dneu.22357] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 10/01/2015] [Accepted: 10/18/2015] [Indexed: 11/09/2022]
Abstract
Physiological studies indicate that the piriform or primary olfactory cortex of adult mammals exhibits a high degree of synaptic plasticity. Interestingly, a subpopulation of cells in the layer II of the adult piriform cortex expresses neurodevelopmental markers, such as the polysialylated form of neural cell adhesion molecule (PSA-NCAM) or doublecortin (DCX). This study analyzes the nature, origin, and potential function of these poorly understood cells in mice. As previously described in rats, most of the PSA-NCAM expressing cells in layer II could be morphologically classified as tangled cells and only a small proportion of larger cells could be considered semilunar-pyramidal transitional neurons. Most were also immunoreactive for DCX, confirming their immature nature. In agreement with this, detection of PSA-NCAM combined with that of different cell lineage-specific antigens revealed that most PSA-NCAM positive cells did not co-express markers of glial cells or mature neurons. Their time of origin was evaluated by birthdating experiments with halogenated nucleosides performed at different developmental stages and in adulthood. We found that virtually all cells in this paleocortical region, including PSA-NCAM-positive cells, are born during fetal development. In addition, proliferation analyses in adult mice revealed that very few cells were cycling in layer II of the piriform cortex and that none of them was PSA-NCAM-positive. Moreover, we have established conditions to isolate and culture these immature neurons in the adult piriform cortex layer II. We find that although they can survive under certain conditions, they do not proliferate in vitro either. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 748-763, 2016.
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Affiliation(s)
- A Rubio
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain.,Centro De Investigaciones Biomédicas En Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - M Belles
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain
| | - G Belenguer
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain.,Centro De Investigaciones Biomédicas En Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - S Vidueira
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain
| | - I Fariñas
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain.,Centro De Investigaciones Biomédicas En Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - J Nacher
- Departamento De Biología Celular, Universidad De Valencia, Burjassot, 46100, Spain.,CIBERSAM: Spanish National Network for Research in Mental Health, Spain.,Fundación Investigación Hospital Clínico De Valencia, INCLIVA, Valencia, 46010, Spain
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30
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Proliferating cells in the adolescent rat amygdala: Characterization and response to stress. Neuroscience 2015; 311:105-17. [PMID: 26476262 DOI: 10.1016/j.neuroscience.2015.10.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Revised: 09/24/2015] [Accepted: 10/02/2015] [Indexed: 12/27/2022]
Abstract
The amygdala is a heterogeneous group of nuclei that plays a role in emotional and social learning. As such, there has been increased interest in its development in adolescent animals, a period in which emotional/social learning increases dramatically. While many mechanisms of amygdala development have been studied, the role of cell proliferation during adolescence has received less attention. Using bromodeoxyuridine (BrdU) injections in adolescent and adult rats, we previously found an almost fivefold increase in BrdU-positive cells in the amygdala of adolescents compared to adults. Approximately one third of BrdU-labeled cells in the amygdala contained the putative neural marker doublecortin (DCX), suggesting a potential for neurogenesis. To further investigate this possibility in adolescents, we examined the proliferative dynamics of DCX/BrdU-labeled cells. Surprisingly, DCX/BrdU-positive cells were found to comprise a stable subpopulation of BrdU-containing cells across survivals up to 56 days, and there was no evidence of neural maturation by 28 days after BrdU injection. Additionally, we found that approximately 50% of BrdU+ cells within the adolescent amygdala contain neural-glial antigen (NG2) and are therefore presumptive oligodendrocyte precursors (OPCs). We next characterized the response to a short-lived stressor (3-day repeated variable stress, RVS). The total BrdU-labeled cell number decreased by ∼30% by 13 days following RVS (10 days post-BrdU injection) as assessed by stereologic counting methods, but the DCX/BrdU-labeled subpopulation was relatively resistant to RVS effects. In contrast, NG2/BrdU-labeled cells were strongly influenced by RVS. We conclude that typical neurogenesis is not a feature of the adolescent amygdala. These findings point to several possibilities, including the possibility that DCX/BrdU cells are late-developing neural precursors, or a unique subtype of NG2 cell that is relatively resistant to stress. In contrast, many proliferating OPCs are significantly impacted by a short-lived stressor, suggesting consequences for myelination in the developing amygdala.
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31
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Yang Y, Xie MX, Li JM, Hu X, Patrylo PR, Luo XG, Cai Y, Li Z, Yan XX. Prenatal genesis of layer II doublecortin expressing neurons in neonatal and young adult guinea pig cerebral cortex. Front Neuroanat 2015; 9:109. [PMID: 26321922 PMCID: PMC4530311 DOI: 10.3389/fnana.2015.00109] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Accepted: 07/27/2015] [Indexed: 12/15/2022] Open
Abstract
Cells expressing doublecortin (DCX+) occur at cortical layer II, predominantly over the paleocortex in mice/rats, but also across the neocortex among larger mammals. Here, we explored the time of origin of these cells in neonatal and 2-month-old guinea pigs following prenatal BrdU pulse-chasing. In the neocortex, BrdU+ cells birth-dated at embryonic day 21 (E21), E28, and E35 laminated over the cortical plate with an inside-out order. In the piriform cortex, cells generated at E21 and E28 occurred with a greater density in layer II than III. Many cells were generated at later time points until birth, occurring in the cortex without a laminar preference. DCX+ cells in the neocortex and piriform cortex partially co-colocalized with BrdU (up to 7.5%) in the newborns after pulse-chasing from E21 to E49 and in the 2 month-old animals after pulse-chasing from E28 to E60/61, with higher rates seen among the E21-E35 groups. Together, layer II DCX+ cells in neonatal and young adult guinea pigs may be produced over a wide prenatal time window, but mainly during the early phases of corticogenesis. Our data also show an earlier establishment of the basic lamination in the piriform relative to neocortical areas in guinea pigs.
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Affiliation(s)
- Yan Yang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China ; Department of Nursing in Internal Medicine, Xiangtan Vocational and Technical College Xiangtan, China
| | - Mi-Xin Xie
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Jian-Ming Li
- Neuroscience Research Center, Changsha Medical University Changsha, China
| | - Xia Hu
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Peter R Patrylo
- Center for Integrated Research in Cognitive and Neural Sciences, Southern Illinois University School of Medicine Carbondale, IL, USA
| | - Xue-Gang Luo
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Yan Cai
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Zhiyuan Li
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
| | - Xiao-Xin Yan
- Department of Anatomy and Neurobiology, Central South University School of Basic Medicine Changsha, China
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32
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Ekonomou A, Savva GM, Brayne C, Forster G, Francis PT, Johnson M, Perry EK, Attems J, Somani A, Minger SL, Ballard CG. Stage-specific changes in neurogenic and glial markers in Alzheimer's disease. Biol Psychiatry 2015; 77:711-9. [PMID: 25022604 DOI: 10.1016/j.biopsych.2014.05.021] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 05/20/2014] [Accepted: 05/23/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND Reports of altered endogenous neurogenesis in people with Alzheimer's disease (AD) and transgenic AD models have suggested that endogenous neurogenesis may be an important treatment target, but there is considerable discrepancy among studies. We examined endogenous neurogenesis and glia changes across the range of pathologic severity of AD in people with and without dementia to address this key question. METHODS Endogenous neurogenesis and glia in the subventricular zone and dentate gyrus neurogenic niches were evaluated using single and double immunohistochemistry and a validated antibody selection for stage-specific and type-specific markers in autopsy tissue from a representative cohort of 28 participants in the Medical Research Council Cognitive Function and Ageing Study. Immunopositive cells were measured blinded to diagnosis using bright-field and fluorescent microscopy. RESULTS The number of newly generated neurons significantly declined only in the dentate gyrus of patients with severe tau pathology. No other changes in other neurogenic markers were observed in either of the neurogenic niches. Alterations in astrocytes and microglia were also observed in the dentate gyrus across the different stages of tau pathology. No change in any of the markers was observed in individuals who died with dementia compared with individuals who did not die with dementia. CONCLUSIONS Alterations in endogenous neurogenesis appeared to be confined to a reduction in the generation of new neurons in the dentate gyrus of patients with AD and severe neurofibrillary tangle pathology and were accompanied by changes in the glia load. These data suggest that intervention enhancing endogenous neurogenesis may be a potential therapeutic target in AD.
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Affiliation(s)
- Antigoni Ekonomou
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom.
| | - George M Savva
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Carol Brayne
- Department of Public Health and Primary Care, University of Cambridge, Cambridge, United Kingdom
| | - Gillian Forster
- Sheffield Institute for Translational Neuroscience, Department of Neuroscience, University of Sheffield, Sheffield, United Kingdom
| | - Paul T Francis
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Mary Johnson
- Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Elaine K Perry
- Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Johannes Attems
- Institute for Ageing and Health, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Alyma Somani
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Stephen L Minger
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
| | - Clive G Ballard
- Wolfson Centre for Age-Related Diseases, King's College London, London, United Kingdom
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Kuipers SD, Schroeder JE, Trentani A. Changes in hippocampal neurogenesis throughout early development. Neurobiol Aging 2014; 36:365-79. [PMID: 25172123 DOI: 10.1016/j.neurobiolaging.2014.07.033] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 07/25/2014] [Accepted: 07/26/2014] [Indexed: 12/18/2022]
Abstract
Adult hippocampal neurogenesis drastically diminishes with age but the underlying mechanisms remain unclear. Here, age-related influences on the hippocampal early neuroprogenitor cell (NPC) pool was examined by quantifying changes in Sox1-expressing cells in the dentate gyrus subgranular zone from early adulthood (3 months) to middle age (12 months). Proliferation of distinct NPC subpopulations (Sox1+, Nestin+, and Doublecortin+) and newborn cell survival were also investigated. Examination of total 5-bromodeoxyuridine (BrdU)+ and Doublecortin (DCX)± cells revealed an early and dramatic age-dependent decline of hippocampal neurogenesis. Increasing age from 3 to 12 months was primarily associated with reduced total proliferation, in vivo (-79% of BrdU+ cells) but not in vitro, and DCX+ cell numbers (-89%). When proliferative rates of individual NPC subpopulations were examined, a different picture emerged as proliferating Nestin+ neuroprogenitors (-95% at 9 months) and BrdU+/DCX+ neuroblasts and/or immature neurons (-83% at 12 months) declined the most, whereas proliferating Sox1+ NPCs only dropped by 53%. Remarkably, despite greatly reduced proliferative rates and recent reports of Nestin+ neuroprogenitor loss, total numbers of early Sox1+ NPCs were unaffected by age (at least up to middle age), and newborn cell survival within the dentate gyrus was increased. Neuronal differentiation was concomitantly reduced; however, thus suggesting age-associated changes in fate-choice determination.
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Affiliation(s)
| | | | - Andrea Trentani
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway; Department of Molecular Neurobiology, Centre for Behaviour and Neurosciences, University of Groningen, Groningen, the Netherlands.
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He X, Zhang XM, Wu J, Fu J, Mou L, Lu DH, Cai Y, Luo XG, Pan A, Yan XX. Olfactory experience modulates immature neuron development in postnatal and adult guinea pig piriform cortex. Neuroscience 2013; 259:101-12. [PMID: 24316472 DOI: 10.1016/j.neuroscience.2013.11.056] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 11/23/2013] [Accepted: 11/25/2013] [Indexed: 10/25/2022]
Abstract
Immature neurons expressing doublecortin (DCX+) are present around cortical layer II in various mammals including guinea pigs and humans, especially enriched in the paleocortex. However, little is known whether and how functional experience affects the development of this population of neurons. We attempted to explore a modulation by experience to layer II DCX+ cells in the primary olfactory cortex in postnatal and adult guinea pigs. Neonatal and 1-year-old guinea pigs were subjected to unilateral naris-occlusion, followed 1 and 2months later by morphometry of DCX+ cells in the piriform cortex. DCX+ somata and processes were reduced in the deprived relative to the non-deprived piriform cortex in both age groups at the two surviving time points. The number of DCX+ cells was decreased in the deprived side relative to internal control at 1 and 2months in the youths and at 2months in the adults post-occlusion. The mean somal area of DCX+ cells showed a trend of decrease in the deprived side relative to the internal control in the youths. In addition, DCX+ cells in the deprived side exhibited a lower frequency of colocalization with the neuron-specific nuclear antigen (NeuN) relative to counterparts. These results suggest that normal olfactory experience is required for the maintenance and development of DCX+ immature neurons in postnatal and adult guinea pig piriform cortex.
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Affiliation(s)
- X He
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China
| | - X-M Zhang
- Department of Neurology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China
| | - J Wu
- Department of Neurology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China
| | - J Fu
- Department of Neurology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China
| | - L Mou
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China; Department of Neurology, The Second Affiliated Hospital, Harbin Medical University, Harbin 150086, China
| | - D-H Lu
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China
| | - Y Cai
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China
| | - X-G Luo
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China
| | - A Pan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China
| | - X-X Yan
- Department of Anatomy and Neurobiology, Central South University Xiangya School of Medicine, Changsha, Hunan 410013, China.
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Saul ML, Helmreich DL, Callahan LM, Fudge JL. Differences in amygdala cell proliferation between adolescent and young adult rats. Dev Psychobiol 2013; 56:517-28. [PMID: 23775606 DOI: 10.1002/dev.21115] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 03/12/2013] [Indexed: 01/10/2023]
Abstract
Adolescence is characterized by changes in both behavior and neural organization. During this period, the amygdala, a structure that mediates social and emotional behaviors, is changing in terms of neural and glia density. We examined cell proliferation within the amygdala of adolescent (post natal day (PND) 31) and adult (PND 70) male Sprague-Dawley rats using BrdU (bromodeoxyuridine) to label dividing cells. BrdU-labeled cells were distributed throughout the amygdala, often found in fibers surrounding major nuclei. Using two independent cell counting strategies under light and confocal microcopy, respectively, we found significantly more labeled cells in the amygdala in adolescent compared to adult animals (239.3 ± 87.18 vs. 44.75 ± 13.68; n=4/group; p<.05). BrdU/doublecortin (DCX) positive cells constitute approximately 30% of all dividing cells in the amygdala in both adolescents and adults. These data suggest that compared to young adulthood, adolescence is a relatively active period of cell proliferation in the amygdala. Moreover, the normal decline in dividing cells with age does not preferentially affect cells co-containing DCX-immunoreactivity.
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Affiliation(s)
- Michele L Saul
- Department of Neurobiology and Anatomy, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY, 14642
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Structural plasticity of interneurons in the adult brain: role of PSA-NCAM and implications for psychiatric disorders. Neurochem Res 2013; 38:1122-33. [PMID: 23354722 DOI: 10.1007/s11064-013-0977-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/12/2013] [Accepted: 01/17/2013] [Indexed: 01/26/2023]
Abstract
Neuronal structural plasticity is known to have a major role in cognitive processes and in the response of the CNS to aversive experiences. This type of plasticity involves processes ranging from neurite outgrowth/retraction or dendritic spine remodeling, to the incorporation of new neurons to the established circuitry. However, the study of how these structural changes take place has been focused mainly on excitatory neurons, while little attention has been paid to interneurons. The exploration of these plastic phenomena in interneurons is very important, not only for our knowledge of CNS physiology, but also for understanding better the etiology of different psychiatric and neurological disorders in which alterations in the structure and connectivity of inhibitory networks have been described. Here we review recent work on the structural remodeling of interneurons in the adult brain, both in basal conditions and after chronic stress or sensory deprivation. We also describe studies from our laboratory and others on the putative mediators of this interneuronal structural plasticity, focusing on the polysialylated form of the neural cell adhesion molecule (PSA-NCAM). This molecule is expressed by some interneurons in the adult CNS and, through its anti-adhesive and insulating properties, may participate in the remodeling of their structure. Finally, we review recent findings on the possible implication of PSA-NCAM on the remodeling of inhibitory neurons in certain psychiatric disorders and their treatments.
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