1
|
Sun Y, Zhang H, Liu R, Wang Y, Zhang X, Huang R, Zhu B, Wu H. Zexieyin formula alleviates Alzheimer's disease via post-synaptic CaMKII modulating AMPA receptor: Involved in promoting neurogenesis to strengthen synaptic plasticity in mice hippocampus. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2024; 131:155802. [PMID: 38852473 DOI: 10.1016/j.phymed.2024.155802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 05/18/2024] [Accepted: 06/02/2024] [Indexed: 06/11/2024]
Abstract
BACKGROUND Alzheimer's disease (AD) is a serious neurodegenerative disease and brings a serious burden to society and families. Due to lack of effective drugs for the treatment of AD, it's urgent to develop new and effective drug for the treatment of AD. PURPOSE The study aimed to investigate the potential of Zexieyin formula (ZXYF), a Chinese medicine formula, for the treatment of AD and its potential mechanism of action. METHODS We used chronic scopolamine (SCOP) induction mice model and APP/PS1 mice to reveal and confirm ZXYF for the treatment of AD with donepezil (DON) as a positive reference. The learning and memory function were detected by morris water maze test (MWM) and y-maze test. Moreover, western blot and immunofluorescence were used to detect the molecular mechanism of ZXYF for the alleviation of AD in hippocampus. Lastly, pharmacological technology was applied to evaluate AMPA receptor involved in the role of ZXYF in the treatment of AD. RESULTS The results showed that ZXYF could improve memory and learning deficits both in two AD models including scopolamine (SCOP)-induced mice model and APP/PS1mice. Moreover, ZXYF or not DON increased expressions of BrdU/DCX and Ki67 positive cells in dentate gyrus (DG), up-regulated the levels of AMPA subunit type (GluA1) and PKA in hippocampus in SCOP-induced mice model, although ZXYF and DON activated CaMKII, CaMKII-phosphorylation, CREB, CREB-phosphorylation and PSD95 in hippocampus in SCOP-induced mice model. ZXYF also activated CaMKII, CaMKII-phosphorylation and GluA1 in HT22 cells. Furthermore, transient inhibiting AMPA receptor was capable of blocking the effects of ZXYF to treat AD in MWM and suppressing the number of BrdU/DCX positive cells increased by ZXYF in DG in SCOP-induced mice model, but had no effect on the alteration of Ki67 positive cells. CONCLUSION ZXYF had the therapeutic effects on AD-treatment, which activated CaMKII to promote AMPA receptor (GluA1) and subsequently up-regulated PKA/CREB signaling to facilitate neurogenesis to achieve enhanced postsynaptic protein.
Collapse
Affiliation(s)
- Yan Sun
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China
| | - Hailou Zhang
- Interdisciplinary Institute for Personalized Medicine in Brain Disorders, Jinan University, Guangzhou 510632, PR China.
| | - Ruiyi Liu
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China; Interdisciplinary Institute for Personalized Medicine in Brain Disorders, Jinan University, Guangzhou 510632, PR China
| | - Yanqing Wang
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China
| | - Xiangrui Zhang
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China
| | - Rumin Huang
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China
| | - Boran Zhu
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China.
| | - Haoxin Wu
- Key Laboratory of Integrative Biomedicine for Brain Diseases, School of Chinese Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, PR China; National Famous Chinese Medicine Expert Inheritance Studio (Meng Jingchun), Nanjing University of Chinese Medicine, School of Chinese Medicine, Nanjing 210023, PR China.
| |
Collapse
|
2
|
Rasetto NB, Giacomini D, Berardino AA, Waichman TV, Beckel MS, Di Bella DJ, Brown J, Davies-Sala MG, Gerhardinger C, Lie DC, Arlotta P, Chernomoretz A, Schinder AF. Transcriptional dynamics orchestrating the development and integration of neurons born in the adult hippocampus. SCIENCE ADVANCES 2024; 10:eadp6039. [PMID: 39028813 PMCID: PMC11259177 DOI: 10.1126/sciadv.adp6039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/13/2024] [Indexed: 07/21/2024]
Abstract
The adult hippocampus generates new granule cells (aGCs) with functional capabilities that convey unique forms of plasticity to the preexisting circuits. While early differentiation of adult radial glia-like cells (RGLs) has been studied extensively, the molecular mechanisms guiding the maturation of postmitotic neurons remain unknown. Here, we used a precise birthdating strategy to study aGC differentiation using single-nuclei RNA sequencing. Transcriptional profiling revealed a continuous trajectory from RGLs to mature aGCs, with multiple immature stages bearing increasing levels of effector genes supporting growth, excitability, and synaptogenesis. Analysis of differential gene expression, pseudo-time trajectory, and transcription factors (TFs) revealed critical transitions defining four cellular states: quiescent RGLs, proliferative progenitors, immature aGCs, and mature aGCs. Becoming mature aGCs involved a transcriptional switch that shuts down pathways promoting cell growth, such SoxC TFs, to activate programs that likely control neuronal homeostasis. aGCs overexpressing Sox4 or Sox11 remained immature. Our results unveil precise molecular mechanisms driving adult RGLs through the pathway of neuronal differentiation.
Collapse
Affiliation(s)
- Natalí B. Rasetto
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, Argentina
| | - Damiana Giacomini
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, Argentina
| | - Ariel A. Berardino
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Integrative Systems Biology, Leloir Institute, Buenos Aires, Argentina
| | - Tomás Vega Waichman
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Integrative Systems Biology, Leloir Institute, Buenos Aires, Argentina
| | - Maximiliano S. Beckel
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Integrative Systems Biology, Leloir Institute, Buenos Aires, Argentina
| | - Daniela J. Di Bella
- Department of Stem Cells and Regenerative Biology, Harvard University and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Juliana Brown
- Department of Stem Cells and Regenerative Biology, Harvard University and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - M. Georgina Davies-Sala
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, Argentina
| | - Chiara Gerhardinger
- Department of Stem Cells and Regenerative Biology, Harvard University and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Dieter Chichung Lie
- Institute of Biochemistry, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Paola Arlotta
- Department of Stem Cells and Regenerative Biology, Harvard University and Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Ariel Chernomoretz
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Integrative Systems Biology, Leloir Institute, Buenos Aires, Argentina
- University of Buenos Aires, School of Science, Phys Dept and INFINA (CONICET-UBA), Buenos Aires, Argentina
| | - Alejandro F. Schinder
- Instituto de Investigaciones Biomédicas de Buenos Aires (IIBBA) – CONICET, Buenos Aires, Argentina
- Laboratory of Neuronal Plasticity, Leloir Institute, Buenos Aires, Argentina
| |
Collapse
|
3
|
Bonzano S, Dallorto E, Bovetti S, Studer M, De Marchis S. Mitochondrial regulation of adult hippocampal neurogenesis: Insights into neurological function and neurodevelopmental disorders. Neurobiol Dis 2024; 199:106604. [PMID: 39002810 DOI: 10.1016/j.nbd.2024.106604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/08/2024] [Accepted: 07/09/2024] [Indexed: 07/15/2024] Open
Abstract
Mitochondria are essential regulators of cellular energy metabolism and play a crucial role in the maintenance and function of neuronal cells. Studies in the last decade have highlighted the importance of mitochondrial dynamics and bioenergetics in adult neurogenesis, a process that significantly influences cognitive function and brain plasticity. In this review, we examine the mechanisms by which mitochondria regulate adult neurogenesis, focusing on the impact of mitochondrial function on the behavior of neural stem/progenitor cells and the maturation and plasticity of newborn neurons in the adult mouse hippocampus. In addition, we explore the link between mitochondrial dysfunction, adult hippocampal neurogenesis and genes associated with cognitive deficits in neurodevelopmental disorders. In particular, we provide insights into how alterations in the transcriptional regulator NR2F1 affect mitochondrial dynamics and may contribute to the pathophysiology of the emerging neurodevelopmental disorder Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS). Understanding how genes involved in embryonic and adult neurogenesis affect mitochondrial function in neurological diseases might open new directions for therapeutic interventions aimed at boosting mitochondrial function during postnatal life.
Collapse
Affiliation(s)
- Sara Bonzano
- Department of Life Sciences and Systems Biology (DBIOS), University of Turin, Via Accademia Albertina 13, Turin 10123, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano 10043, Italy
| | - Eleonora Dallorto
- Department of Life Sciences and Systems Biology (DBIOS), University of Turin, Via Accademia Albertina 13, Turin 10123, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano 10043, Italy; Institute de Biologie Valrose (iBV), Université Cote d'Azur (UCA), CNRS 7277, Inserm 1091, Avenue Valrose 28, Nice 06108, France
| | - Serena Bovetti
- Department of Life Sciences and Systems Biology (DBIOS), University of Turin, Via Accademia Albertina 13, Turin 10123, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano 10043, Italy
| | - Michèle Studer
- Institute de Biologie Valrose (iBV), Université Cote d'Azur (UCA), CNRS 7277, Inserm 1091, Avenue Valrose 28, Nice 06108, France
| | - Silvia De Marchis
- Department of Life Sciences and Systems Biology (DBIOS), University of Turin, Via Accademia Albertina 13, Turin 10123, Italy; Neuroscience Institute Cavalieri Ottolenghi (NICO), Regione Gonzole 10, Orbassano 10043, Italy.
| |
Collapse
|
4
|
Blum Moyse L, Berry H. A coupled neural field model for the standard consolidation theory. J Theor Biol 2024; 588:111818. [PMID: 38621583 DOI: 10.1016/j.jtbi.2024.111818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 03/29/2024] [Accepted: 04/03/2024] [Indexed: 04/17/2024]
Abstract
The standard consolidation theory states that short-term memories located in the hippocampus enable the consolidation of long-term memories in the neocortex. In other words, the neocortex slowly learns long-term memories with a transient support of the hippocampus that quickly learns unstable memories. However, it is not clear yet what could be the neurobiological mechanisms underlying these differences in learning rates and memory time-scales. Here, we propose a novel modeling approach of the standard consolidation theory, that focuses on its potential neurobiological mechanisms. In addition to synaptic plasticity and spike frequency adaptation, our model incorporates adult neurogenesis in the dentate gyrus as well as the difference in size between the neocortex and the hippocampus, that we associate with distance-dependent synaptic plasticity. We also take into account the interconnected spatial structure of the involved brain areas, by incorporating the above neurobiological mechanisms in a coupled neural field framework, where each area is represented by a separate neural field with intra- and inter-area connections. To our knowledge, this is the first attempt to apply neural fields to this process. Using numerical simulations and mathematical analysis, we explore the short-term and long-term dynamics of the model upon alternance of phases of hippocampal replay and retrieval cue of an external input. This external input is encodable as a memory pattern in the form of a multiple bump attractor pattern in the individual neural fields. In the model, hippocampal memory patterns become encoded first, before neocortical ones, because of the smaller distances between the bumps of the hippocampal memory patterns. As a result, retrieval of the input pattern in the neocortex at short time-scales necessitates the additional input delivered by the memory pattern of the hippocampus. Neocortical memory patterns progressively consolidate at longer times, up to a point where their retrieval does not need the support of the hippocampus anymore. At longer times, perturbation of the hippocampal neural fields by neurogenesis erases the hippocampus pattern, leading to a final state where the memory pattern is exclusively evoked in the neocortex. Therefore, the dynamics of our model successfully reproduces the main features of the standard consolidation theory. This suggests that neurogenesis in the hippocampus and distance-dependent synaptic plasticity coupled to synaptic depression and spike frequency adaptation, are indeed critical neurobiological processes in memory consolidation.
Collapse
Affiliation(s)
- Lisa Blum Moyse
- LIRIS, CNRS UMR 5205, Villeurbanne, F-69621, France; AIstroSight, Inria, Hospices Civils de Lyon, Universite Claude Bernard Lyon 1, Villeurbanne, F-69603, France.
| | - Hugues Berry
- AIstroSight, Inria, Hospices Civils de Lyon, Universite Claude Bernard Lyon 1, Villeurbanne, F-69603, France.
| |
Collapse
|
5
|
De Paolis ML, Paoletti I, Zaccone C, Capone F, D'Amelio M, Krashia P. Transcranial alternating current stimulation (tACS) at gamma frequency: an up-and-coming tool to modify the progression of Alzheimer's Disease. Transl Neurodegener 2024; 13:33. [PMID: 38926897 PMCID: PMC11210106 DOI: 10.1186/s40035-024-00423-y] [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: 01/08/2024] [Accepted: 05/24/2024] [Indexed: 06/28/2024] Open
Abstract
The last decades have witnessed huge efforts devoted to deciphering the pathological mechanisms underlying Alzheimer's Disease (AD) and to testing new drugs, with the recent FDA approval of two anti-amyloid monoclonal antibodies for AD treatment. Beyond these drug-based experimentations, a number of pre-clinical and clinical trials are exploring the benefits of alternative treatments, such as non-invasive stimulation techniques on AD neuropathology and symptoms. Among the different non-invasive brain stimulation approaches, transcranial alternating current stimulation (tACS) is gaining particular attention due to its ability to externally control gamma oscillations. Here, we outline the current knowledge concerning the clinical efficacy, safety, ease-of-use and cost-effectiveness of tACS on early and advanced AD, applied specifically at 40 Hz frequency, and also summarise pre-clinical results on validated models of AD and ongoing patient-centred trials.
Collapse
Affiliation(s)
- Maria Luisa De Paolis
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Ilaria Paoletti
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Claudio Zaccone
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| | - Fioravante Capone
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Via Alvaro del Portillo, 200 - 00128, Rome, Italy
| | - Marcello D'Amelio
- Department of Medicine and Surgery, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy.
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Via del Fosso Di Fiorano, 64 - 00143, Rome, Italy.
| | - Paraskevi Krashia
- Department of Experimental Neurosciences, IRCCS Santa Lucia Foundation, Via del Fosso Di Fiorano, 64 - 00143, Rome, Italy
- Department of Sciences and Technologies for Sustainable Development and One Health, Università Campus Bio-Medico Di Roma, Via Alvaro del Portillo, 21 - 00128, Rome, Italy
| |
Collapse
|
6
|
Kochan SMV, Malo MC, Jevtic M, Jahn-Kelleter HM, Wani GA, Ndoci K, Pérez-Revuelta L, Gaedke F, Schäffner I, Lie DC, Schauss A, Bergami M. Enhanced mitochondrial fusion during a critical period of synaptic plasticity in adult-born neurons. Neuron 2024; 112:1997-2014.e6. [PMID: 38582081 DOI: 10.1016/j.neuron.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 01/25/2024] [Accepted: 03/11/2024] [Indexed: 04/08/2024]
Abstract
Integration of new neurons into adult hippocampal circuits is a process coordinated by local and long-range synaptic inputs. To achieve stable integration and uniquely contribute to hippocampal function, immature neurons are endowed with a critical period of heightened synaptic plasticity, yet it remains unclear which mechanisms sustain this form of plasticity during neuronal maturation. We found that as new neurons enter their critical period, a transient surge in fusion dynamics stabilizes elongated mitochondrial morphologies in dendrites to fuel synaptic plasticity. Conditional ablation of fusion dynamics to prevent mitochondrial elongation selectively impaired spine plasticity and synaptic potentiation, disrupting neuronal competition for stable circuit integration, ultimately leading to decreased survival. Despite profuse mitochondrial fragmentation, manipulation of competition dynamics was sufficient to restore neuronal survival but left neurons poorly responsive to experience at the circuit level. Thus, by enabling synaptic plasticity during the critical period, mitochondrial fusion facilitates circuit remodeling by adult-born neurons.
Collapse
Affiliation(s)
- Sandra M V Kochan
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Meret Cepero Malo
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Milica Jevtic
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Hannah M Jahn-Kelleter
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Gulzar A Wani
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Kristiano Ndoci
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Laura Pérez-Revuelta
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Felix Gaedke
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Iris Schäffner
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Dieter Chichung Lie
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Astrid Schauss
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Matteo Bergami
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany; Center for Molecular Medicine, 50931 Cologne, Germany; Institute of Genetics, University of Cologne, Cologne 50674, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, 50937 Cologne, Germany.
| |
Collapse
|
7
|
Wang L, Gu Y. Fuse mitochondria to win peer competition. Neuron 2024; 112:1897-1899. [PMID: 38901399 DOI: 10.1016/j.neuron.2024.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 05/04/2024] [Accepted: 05/06/2024] [Indexed: 06/22/2024]
Abstract
In this issue of Neuron, Kochan et al.1 report that enhanced mitochondrial fusion is essential for the heightened synaptic plasticity in adult-born neurons during the critical period, thus supporting their competition with neurons of similar age for survival.
Collapse
Affiliation(s)
- Lang Wang
- Department of Neurology of the First Affiliated Hospital, Interdisciplinary Institute of Neuroscience and Technology, Zhejiang University School of Medicine, Hangzhou 310027, China; School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou 310058, China
| | - Yan Gu
- Center of Stem Cell and Regenerative Medicine, and Department of Neurology of the Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China; MOE Frontier Science Center for Brain Science & Brain-Machine Integration, Zhejiang University, Hangzhou 310058, China.
| |
Collapse
|
8
|
Liu Y, Zhang J, Gu X, Jia S. Mapping the current trends and hotspots of adult hippocampal neurogenesis from 2004-2023: a bibliometric analysis. Front Neurosci 2024; 18:1416738. [PMID: 38957185 PMCID: PMC11217541 DOI: 10.3389/fnins.2024.1416738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2024] [Accepted: 06/06/2024] [Indexed: 07/04/2024] Open
Abstract
Objective We utilized bibliometric and data visualization techniques to discern the primary research domains and emerging frontiers in the field of adult hippocampal neurogenesis (AHN). Methods We systematically searched the Web of Science database for AHN-related articles published between 2004 and 2023. The retrieved articles were filtered based on publication types (articles and reviews) and language (English). We employed CiteSpace, VOSviewer, and the online bibliometric platform (bibliometric.com) to visualize and analyze the collected data. Results In total, 1,590 AHN-related publications were discovered, exhibiting a steady increase in yearly publications over time. The United States emerged as the leading contributor in AHN research in terms of both publication quantity and national influence. Among all research institutions in the field of AHN, the University of California System exhibited the highest impact. Kempermann, Gerd was the most active author. The publications of the top three active authors primarily focused on the functions of AHN, and reversing hippocampal damage and cognitive impairment by improving AHN. An analysis of reference co-citation clustering revealed 8 distinct research clusters, and the notable ones included "adult hippocampal neurogenesis," "neurogenesis," "hippocampus," "dentate gyrus," "neural stem cell," and "depression." Additionally, a burst keyword detection indicated that 'anxiety' is a current research hotspot in the field of AHN. Conclusion This in-depth bibliographic assessment of AHN offers a deeper insight into the present research hotspots in the field. The association between AHN and cognitive diseases, such as Alzheimer's disease (AD) and anxiety, has emerged as a prominent research hotspot.
Collapse
Affiliation(s)
- Ye Liu
- The Second School of Clinical Medicine of Binzhou Medical University, Yantai, Shandong Province, China
- Department of Anesthesiology, Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai, China
| | - Jian Zhang
- Department of Anesthesiology, The International Peace Maternity and Child Health Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xiyao Gu
- The Second School of Clinical Medicine of Binzhou Medical University, Yantai, Shandong Province, China
- Department of Anesthesiology, Department of Radiology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Key Laboratory of Anesthesiology (Shanghai Jiao Tong University), Ministry of Education, Shanghai, China
| | - Shushan Jia
- The Second School of Clinical Medicine of Binzhou Medical University, Yantai, Shandong Province, China
| |
Collapse
|
9
|
Arellano JI, Rakic P. Modelling adult neurogenesis in the aging rodent hippocampus: a midlife crisis. Front Neurosci 2024; 18:1416460. [PMID: 38887368 PMCID: PMC11181911 DOI: 10.3389/fnins.2024.1416460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
Contrary to humans, adult hippocampal neurogenesis in rodents is not controversial. And in the last three decades, multiple studies in rodents have deemed adult neurogenesis essential for most hippocampal functions. The functional relevance of new neurons relies on their distinct physiological properties during their maturation before they become indistinguishable from mature granule cells. Most functional studies have used very young animals with robust neurogenesis. However, this trait declines dramatically with age, questioning its functional relevance in aging animals, a caveat that has been mentioned repeatedly, but rarely analyzed quantitatively. In this meta-analysis, we use data from published studies to determine the critical functional window of new neurons and to model their numbers across age in both mice and rats. Our model shows that new neurons with distinct functional profile represent about 3% of the total granule cells in young adult 3-month-old rodents, and their number decline following a power function to reach less than 1% in middle aged animals and less than 0.5% in old mice and rats. These low ratios pose an important logical and computational caveat to the proposed essential role of new neurons in the dentate gyrus, particularly in middle aged and old animals, a factor that needs to be adequately addressed when defining the relevance of adult neurogenesis in hippocampal function.
Collapse
Affiliation(s)
- Jon I. Arellano
- Department of Neuroscience, Yale University, New Haven, CT, United States
| | - Pasko Rakic
- Department of Neuroscience, Yale University, New Haven, CT, United States
- Kavli Institute for Neuroscience at Yale, Yale University, New Haven, CT, United States
| |
Collapse
|
10
|
Kennedy WM, Gonzalez JC, Lee H, Wadiche JI, Overstreet-Wadiche L. T-Type Ca 2+ Channels Mediate a Critical Period of Plasticity in Adult-Born Granule Cells. J Neurosci 2024; 44:e1503232024. [PMID: 38413230 PMCID: PMC11007310 DOI: 10.1523/jneurosci.1503-23.2024] [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: 08/08/2023] [Revised: 01/26/2024] [Accepted: 02/20/2024] [Indexed: 02/29/2024] Open
Abstract
Adult-born granule cells (abGCs) exhibit a transient period of elevated synaptic plasticity that plays an important role in hippocampal function. Various mechanisms have been implicated in this critical period for enhanced plasticity, including minimal GABAergic inhibition and high intrinsic excitability conferred by T-type Ca2+ channels. Here we assess the contribution of synaptic inhibition and intrinsic excitability to long-term potentiation (LTP) in abGCs of adult male and female mice using perforated patch recordings. We show that the timing of critical period plasticity is unaffected by intact GABAergic inhibition such that 4-6-week-old abGCs exhibit LTP that is absent by 8 weeks. Blocking GABAA receptors, or partial blockade of GABA release from PV and nNos-expressing interneurons by a µ-opioid receptor agonist, strongly enhances LTP in 4-week-old GCs, suggesting that minimal inhibition does not underlie critical period plasticity. Instead, the closure of the critical period coincides with a reduction in the contribution of T-type Ca2+ channels to intrinsic excitability, and a selective T-type Ca2+ channel antagonist prevents LTP in 4-week-old but not mature GCs. Interestingly, whole-cell recordings that facilitate T-type Ca2+ channel activity in mature GCs unmasks LTP (with inhibition intact) that is also sensitive to a T-type Ca2+ channel antagonist, suggesting T-type channel activity in mature GCs is suppressed by native intracellular signaling. Together these results show that abGCs use T-type Ca2+ channels to overcome inhibition, providing new insight into how high intrinsic excitability provides young abGCs a competitive advantage for experience-dependent synaptic plasticity.
Collapse
Affiliation(s)
- William M Kennedy
- Department of Neurobiology and McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jose Carlos Gonzalez
- Department of Neurobiology and McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Haeun Lee
- Department of Neurobiology and McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Jacques I Wadiche
- Department of Neurobiology and McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| | - Linda Overstreet-Wadiche
- Department of Neurobiology and McKnight Brain Institute, University of Alabama at Birmingham, Birmingham, Alabama 35294
| |
Collapse
|
11
|
Guo X, Qiu W, Li B, Qi Y, Wang S, Zhao R, Cheng B, Han X, Du H, Pan Z, Zhao S, Qiu J, Li G, Xue H. Hypoxia-Induced Neuronal Activity in Glioma Patients Polarizes Microglia by Potentiating RNA m6A Demethylation. Clin Cancer Res 2024; 30:1160-1174. [PMID: 37855702 DOI: 10.1158/1078-0432.ccr-23-0430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 08/22/2023] [Accepted: 10/17/2023] [Indexed: 10/20/2023]
Abstract
PURPOSE Neuronal activity in the brain has been reported to promote the malignant progression of glioma cells via nonsynaptic paracrine and electrical synaptic integration mechanisms. However, the interaction between neuronal activity and the immune microenvironment in glioblastoma (GBM) remains largely unclear. EXPERIMENTAL DESIGN By applying chemogenetic techniques, we enhanced and inhibited neuronal activity in vitro and in a mouse model to study how neuronal activity regulates microglial polarization and affects GBM progression. RESULTS We demonstrate that hypoxia drove glioma stem cells (GSC) to produce higher levels of glutamate, which activated local neurons. Neuronal activity promoted GBM progression by facilitating microglial M2 polarization through enriching miR-200c-3p in neuron-derived exosomes, which decreased the expression of the m6A writer zinc finger CCCH-type containing 13 (ZC3H13) in microglia, impairing methylation of dual specificity phosphatase 9 (DUSP9) mRNA. Downregulation of DUSP9 promoted ERK pathway activation, which subsequently induced microglial M2 polarization. In the mouse model, cortical neuronal activation promoted microglial M2 polarization whereas cortical neuronal inhibition decreased microglial M2 polarization in GBM xenografts. miR-200c-3p knockdown in cortical neurons impaired microglial M2 polarization and GBM xenograft growth, even when cortical neurons were activated. Treatment with the anti-seizure medication levetiracetam impaired neuronal activation and subsequently reduced neuron-mediated microglial M2 polarization. CONCLUSIONS These findings indicated that hypoxic GSC-induced neuron activation promotes GBM progression by polarizing microglia via the exosomal miR-200c-3p/ZC3H13/DUSP9/p-ERK pathway. Levetiracetam, an antiepileptic drug, blocks the abnormal activation of neurons in GBM and impairs activity-dependent GBM progression. See related commentary by Cui et al., p. 1073.
Collapse
Affiliation(s)
- Xiaofan Guo
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
- Department of Neurology, Loma Linda University Health, Loma Linda, California
| | - Wei Qiu
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Boyan Li
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Yanhua Qi
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Shaobo Wang
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Rongrong Zhao
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Bo Cheng
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
- Department of Radiation Oncology, Qilu Hospital of Shandong University, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, China
| | - Xiao Han
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
- Department of Neurosurgery, Jinan Children's Hospital, Jinan, Shandong, China
| | - Hao Du
- Department of Cell Biology, University of Connecticut School of Medicine, Farmington, Connecticut
| | - Ziwen Pan
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Shulin Zhao
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Jiawei Qiu
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Gang Li
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| | - Hao Xue
- Department of Neurosurgery, Qilu Hospital, Cheeloo College of Medicine and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Brain Function Remodeling, Jinan, Shandong, China
| |
Collapse
|
12
|
Rawat R, Tunc-Ozcan E, Dunlop S, Tsai YH, Li F, Bertossi R, Peng CY, Kessler JA. Ketamine's rapid and sustained antidepressant effects are driven by distinct mechanisms. Cell Mol Life Sci 2024; 81:105. [PMID: 38413417 PMCID: PMC10899278 DOI: 10.1007/s00018-024-05121-6] [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: 08/30/2023] [Revised: 01/03/2024] [Accepted: 01/08/2024] [Indexed: 02/29/2024]
Abstract
Administration of multiple subanesthetic doses of ketamine increases the duration of antidepressant effects relative to a single ketamine dose, but the mechanisms mediating this sustained effect are unclear. Here, we demonstrate that ketamine's rapid and sustained effects on affective behavior are mediated by separate and temporally distinct mechanisms. The rapid effects of a single dose of ketamine result from increased activity of immature neurons in the hippocampal dentate gyrus without an increase in neurogenesis. Treatment with six doses of ketamine over two weeks doubled the duration of behavioral effects after the final ketamine injection. However, unlike ketamine's rapid effects, this more sustained behavioral effect did not correlate with increased immature neuron activity but instead correlated with increased numbers of calretinin-positive and doublecortin-positive immature neurons. This increase in neurogenesis was associated with a decrease in bone morphogenetic protein (BMP) signaling, a known inhibitor of neurogenesis. Injection of a BMP4-expressing lentivirus into the dentate gyrus maintained BMP signaling in the niche and blocked the sustained - but not the rapid - behavioral effects of ketamine, indicating that decreased BMP signaling is necessary for ketamine's sustained effects. Thus, although the rapid effects of ketamine result from increased activity of immature neurons in the dentate gyrus without requiring an increase in neurogenesis, ketamine's sustained effects require a decrease in BMP signaling and increased neurogenesis along with increased neuron activity. Understanding ketamine's dual mechanisms of action should help with the development of new rapid-acting therapies that also have safe, reliable, and sustained effects.
Collapse
Affiliation(s)
- Radhika Rawat
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA.
| | - Elif Tunc-Ozcan
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - Sara Dunlop
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - Yung-Hsu Tsai
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - Fangze Li
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - Ryan Bertossi
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - Chian-Yu Peng
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| | - John A Kessler
- Department of Neurology, Feinberg School of Medicine, Northwestern University, 303 E. Chicago Ave, Ward 10-233, Chicago, IL, 60611, USA
| |
Collapse
|
13
|
Li H, Tamura R, Hayashi D, Asai H, Koga J, Ando S, Yokota S, Kaneko J, Sakurai K, Sumiyoshi A, Yamamoto T, Hikishima K, Tanaka KZ, McHugh TJ, Hisatsune T. Silencing dentate newborn neurons alters excitatory/inhibitory balance and impairs behavioral inhibition and flexibility. SCIENCE ADVANCES 2024; 10:eadk4741. [PMID: 38198539 PMCID: PMC10780870 DOI: 10.1126/sciadv.adk4741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024]
Abstract
Adult neurogenesis confers the hippocampus with unparalleled neural plasticity, essential for intricate cognitive functions. The specific influence of sparse newborn neurons (NBNs) in modulating neural activities and subsequently steering behavior, however, remains obscure. Using an engineered NBN-tetanus toxin mouse model (NBN-TeTX), we noninvasively silenced NBNs, elucidating their crucial role in impulse inhibition and cognitive flexibility as evidenced through Morris water maze reversal learning and Go/Nogo task in operant learning. Task-based functional MRI (tb-fMRI) paired with operant learning revealed dorsal hippocampal hyperactivation during the Nogo task in male NBN-TeTX mice, suggesting that hippocampal hyperexcitability might underlie the observed behavioral deficits. Additionally, resting-state fMRI (rs-fMRI) exhibited enhanced functional connectivity between the dorsal and ventral dentate gyrus following NBN silencing. Further investigations into the activities of PV+ interneurons and mossy cells highlighted the indispensability of NBNs in maintaining the hippocampal excitation/inhibition balance. Our findings emphasize that the neural plasticity driven by NBNs extensively modulates the hippocampus, sculpting inhibitory control and cognitive flexibility.
Collapse
Affiliation(s)
- Haowei Li
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Risako Tamura
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Daiki Hayashi
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Hirotaka Asai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Junya Koga
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Shota Ando
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Sayumi Yokota
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Jun Kaneko
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Keisuke Sakurai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| | - Akira Sumiyoshi
- Department of Molecular Imaging and Theranostics, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tadashi Yamamoto
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Keigo Hikishima
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Kazumasa Z. Tanaka
- Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Thomas J. McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Saitama, Japan
| | - Tatsuhiro Hisatsune
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Japan
| |
Collapse
|
14
|
Rasetto NB, Giacomini D, Berardino AA, Waichman TV, Beckel MS, Di Bella DJ, Brown J, Davies-Sala MG, Gerhardinger C, Lie DC, Arlotta P, Chernomoretz A, Schinder AF. Transcriptional dynamics orchestrating the development and integration of neurons born in the adult hippocampus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.03.565477. [PMID: 38260428 PMCID: PMC10802403 DOI: 10.1101/2023.11.03.565477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The adult hippocampus generates new granule cells (aGCs) that exhibit distinct functional capabilities along development, conveying a unique form of plasticity to the preexisting circuits. While early differentiation of adult radial glia-like neural stem cells (RGL) has been studied extensively, the molecular mechanisms guiding the maturation of postmitotic neurons remain unknown. Here, we used a precise birthdating strategy to follow newborn aGCs along differentiation using single-nuclei RNA sequencing (snRNA-seq). Transcriptional profiling revealed a continuous trajectory from RGLs to mature aGCs, with multiple sequential immature stages bearing increasing levels of effector genes supporting growth, excitability and synaptogenesis. Remarkably, four discrete cellular states were defined by the expression of distinct sets of transcription factors (TFs): quiescent neural stem cells, proliferative progenitors, postmitotic immature aGCs, and mature aGCs. The transition from immature to mature aCGs involved a transcriptional switch that shutdown molecular cascades promoting cell growth, such as the SoxC family of TFs, to activate programs controlling neuronal homeostasis. Indeed, aGCs overexpressing Sox4 or Sox11 remained stalled at the immature state. Our results unveil precise molecular mechanisms driving adult neural stem cells through the pathway of neuronal differentiation.
Collapse
|
15
|
Singh S, Becker S, Trappenberg T, Nunes A. Granule cells perform frequency-dependent pattern separation in a computational model of the dentate gyrus. Hippocampus 2024; 34:14-28. [PMID: 37950569 DOI: 10.1002/hipo.23585] [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: 05/14/2023] [Revised: 09/28/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023]
Abstract
Mnemonic discrimination (MD) may be dependent on oscillatory perforant path input frequencies to the hippocampus in a "U"-shaped fashion, where some studies show that slow and fast input frequencies support MD, while other studies show that intermediate frequencies disrupt MD. We hypothesize that pattern separation (PS) underlies frequency-dependent MD performance. We aim to study, in a computational model of the hippocampal dentate gyrus (DG), the network and cellular mechanisms governing this putative "U"-shaped PS relationship. We implemented a biophysical model of the DG that produces the hypothesized "U"-shaped input frequency-PS relationship, and its associated oscillatory electrophysiological signatures. We subsequently evaluated the network's PS ability using an adapted spatiotemporal task. We undertook systematic lesion studies to identify the network-level mechanisms driving the "U"-shaped input frequency-PS relationship. A minimal circuit of a single granule cell (GC) stimulated with oscillatory inputs was also used to study potential cellular-level mechanisms. Lesioning synapses onto GCs did not impact the "U"-shaped input frequency-PS relationship. Furthermore, GC inhibition limits PS performance for fast frequency inputs, while enhancing PS for slow frequency inputs. GC interspike interval was found to be input frequency dependent in a "U"-shaped fashion, paralleling frequency-dependent PS observed at the network level. Additionally, GCs showed an attenuated firing response for fast frequency inputs. We conclude that independent of network-level inhibition, GCs may intrinsically be capable of producing a "U"-shaped input frequency-PS relationship. GCs may preferentially decorrelate slow and fast inputs via spike timing reorganization and high frequency filtering.
Collapse
Affiliation(s)
- Selena Singh
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Suzanna Becker
- Department of Psychology, Neuroscience and Behaviour, McMaster University, Hamilton, Ontario, Canada
| | - Thomas Trappenberg
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Abraham Nunes
- Faculty of Computer Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
16
|
Chang WL, Hen R. Adult Neurogenesis, Context Encoding, and Pattern Separation: A Pathway for Treating Overgeneralization. ADVANCES IN NEUROBIOLOGY 2024; 38:163-193. [PMID: 39008016 DOI: 10.1007/978-3-031-62983-9_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
In mammals, the subgranular zone of the dentate gyrus is one of two brain regions (with the subventricular zone of the olfactory bulb) that continues to generate new neurons throughout adulthood, a phenomenon known as adult hippocampal neurogenesis (AHN) (Eriksson et al., Nat Med 4:1313-1317, 1998; García-Verdugo et al., J Neurobiol 36:234-248, 1998). The integration of these new neurons into the dentate gyrus (DG) has implications for memory encoding, with unique firing and wiring properties of immature neurons that affect how the hippocampal network encodes and stores attributes of memory. In this chapter, we will describe the process of AHN and properties of adult-born cells as they integrate into the hippocampal circuit and mature. Then, we will discuss some methodological considerations before we review evidence for the role of AHN in two major processes supporting memory that are performed by the DG. First, we will discuss encoding of contextual information for episodic memories and how this is facilitated by AHN. Second, will discuss pattern separation, a major role of the DG that reduces interference for the formation of new memories. Finally, we will review clinical and translational considerations, suggesting that stimulation of AHN may help decrease overgeneralization-a common endophenotype of mood, anxiety, trauma-related, and age-related disorders.
Collapse
Affiliation(s)
- Wei-Li Chang
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY, USA
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY, USA
| | - Rene Hen
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY, USA.
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY, USA.
| |
Collapse
|
17
|
Tuncdemir SN, Grosmark AD, Chung H, Luna VM, Lacefield CO, Losonczy A, Hen R. Adult-born granule cells facilitate remapping of spatial and non-spatial representations in the dentate gyrus. Neuron 2023; 111:4024-4039.e7. [PMID: 37820723 PMCID: PMC10841867 DOI: 10.1016/j.neuron.2023.09.016] [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: 12/07/2022] [Revised: 06/10/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
Adult-born granule cells (abGCs) have been implicated in memory discrimination through a neural computation known as pattern separation. Here, using in vivo Ca2+ imaging, we examined how chronic ablation or acute chemogenetic silencing of abGCs affects the activity of mature granule cells (mGCs). In both cases, we observed altered remapping of mGCs. Rather than broadly modulating the activity of all mGCs, abGCs promote the remapping of place cells' firing fields while increasing rate remapping of mGCs that represent sensory cues. In turn, these remapping deficits are associated with behavioral impairments in animals' ability to correctly identify new goal locations. Thus, abGCs facilitate pattern separation through the formation of non-overlapping representations for identical sensory cues encountered in different locations. In the absence of abGCs, the dentate gyrus shifts to a state that is dominated by cue information, a situation that is consistent with the overgeneralization often observed in anxiety or age-related disorders.
Collapse
Affiliation(s)
- Sebnem N Tuncdemir
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Andres D Grosmark
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Hannah Chung
- Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Victor M Luna
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Clay O Lacefield
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA
| | - Attila Losonczy
- Department of Neuroscience, Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Rene Hen
- Departments of Psychiatry and Neuroscience, Columbia University, New York, NY 10032, USA; Division of Systems Neuroscience, New York State Psychiatric Institute, New York, NY 10032, USA.
| |
Collapse
|
18
|
Luo X, Xu M, Guo W. Adult neurogenesis research in China. Dev Growth Differ 2023; 65:534-545. [PMID: 37899611 DOI: 10.1111/dgd.12900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/22/2023] [Accepted: 10/25/2023] [Indexed: 10/31/2023]
Abstract
Neural stem cells are multipotent stem cells that generate functional newborn neurons through a process called neurogenesis. Neurogenesis in the adult brain is tightly regulated and plays a pivotal role in the maintenance of brain function. Disruption of adult neurogenesis impairs cognitive function and is correlated with numerous neurologic disorders. Deciphering the mechanisms underlying adult neurogenesis not only advances our understanding of how the brain functions, but also offers new insight into neurologic diseases and potentially contributes to the development of effective treatments. The field of adult neurogenesis is experiencing significant growth in China. Chinese researchers have demonstrated a multitude of factors governing adult neurogenesis and revealed the underlying mechanisms of and correlations between adult neurogenesis and neurologic disorders. Here, we provide an overview of recent advancements in the field of adult neurogenesis due to Chinese scientists.
Collapse
Affiliation(s)
- Xing Luo
- State Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Mingyue Xu
- State Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School, University of Chinese Academy of Sciences, Beijing, China
| | - Weixiang Guo
- State Key Laboratory for Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
- Graduate School, University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
19
|
Malik SC, Lin JD, Ziegler-Waldkirch S, Tholen S, Deshpande SS, Schwabenland M, Schilling O, Vlachos A, Meyer-Luehmann M, Schachtrup C. Tpr Misregulation in Hippocampal Neural Stem Cells in Mouse Models of Alzheimer's Disease. Cells 2023; 12:2757. [PMID: 38067185 PMCID: PMC10706632 DOI: 10.3390/cells12232757] [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: 09/11/2023] [Revised: 11/19/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Nuclear pore complexes (NPCs) are highly dynamic macromolecular protein structures that facilitate molecular exchange across the nuclear envelope. Aberrant NPC functioning has been implicated in neurodegeneration. The translocated promoter region (Tpr) is a critical scaffolding nucleoporin (Nup) of the nuclear basket, facing the interior of the NPC. However, the role of Tpr in adult neural stem/precursor cells (NSPCs) in Alzheimer's disease (AD) is unknown. Using super-resolution (SR) and electron microscopy, we defined the different subcellular localizations of Tpr and phospho-Tpr (P-Tpr) in NSPCs in vitro and in vivo. Elevated Tpr expression and reduced P-Tpr nuclear localization accompany NSPC differentiation along the neurogenic lineage. In 5xFAD mice, an animal model of AD, increased Tpr expression in DCX+ hippocampal neuroblasts precedes increased neurogenesis at an early stage, before the onset of amyloid-β plaque formation. Whereas nuclear basket Tpr interacts with chromatin modifiers and NSPC-related transcription factors, P-Tpr interacts and co-localizes with cyclin-dependent kinase 1 (Cdk1) at the nuclear chromatin of NSPCs. In hippocampal NSPCs in a mouse model of AD, aberrant Tpr expression was correlated with altered NPC morphology and counts, and Tpr was aberrantly expressed in postmortem human brain samples from patients with AD. Thus, we propose that altered levels and subcellular localization of Tpr in CNS disease affect Tpr functionality, which in turn regulates the architecture and number of NSPC NPCs, possibly leading to aberrant neurogenesis.
Collapse
Affiliation(s)
- Subash C. Malik
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Jia-Di Lin
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Stephanie Ziegler-Waldkirch
- Department of Neurology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (S.Z.-W.); (M.M.-L.)
| | - Stefan Tholen
- Institute of Surgical Pathology, Medical Center, University of Freiburg, 79106 Freiburg, Germany; (S.T.); (O.S.)
| | - Sachin S. Deshpande
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Marius Schwabenland
- Institute of Neuropathology, University of Freiburg, 79106 Freiburg, Germany
| | - Oliver Schilling
- Institute of Surgical Pathology, Medical Center, University of Freiburg, 79106 Freiburg, Germany; (S.T.); (O.S.)
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
- Center BrainLinks-BrainTools, University of Freiburg, 79110 Freiburg, Germany
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Melanie Meyer-Luehmann
- Department of Neurology, Medical Center, Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany; (S.Z.-W.); (M.M.-L.)
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| | - Christian Schachtrup
- Institute of Anatomy and Cell Biology, University of Freiburg, 79104 Freiburg, Germany; (S.C.M.); (J.-D.L.); (S.S.D.)
- Center for Basics in Neuromodulation (NeuroModul Basics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
| |
Collapse
|
20
|
Ji Q, Yang Y, Xiong Y, Zhang YJ, Jiang J, Zhou LP, Du XH, Wang CX, Zhu ZR. Blockade of adenosine A 2A receptors reverses early spatial memory defects in the APP/PS1 mouse model of Alzheimer's disease by promoting synaptic plasticity of adult-born granule cells. Alzheimers Res Ther 2023; 15:187. [PMID: 37899431 PMCID: PMC10614339 DOI: 10.1186/s13195-023-01337-z] [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: 04/17/2023] [Accepted: 10/17/2023] [Indexed: 10/31/2023]
Abstract
BACKGROUND The over-activation of adenosine A2A receptors (A2AR) is closely implicated in cognitive impairments of Alzheimer's disease (AD). Growing evidence shows that A2AR blockade possesses neuroprotective effects on AD. Spatial navigation impairment is an early manifestation of cognitive deficits in AD. However, whether A2AR blockade can prevent early impairments in spatial cognitive function and the underlying mechanism is still unclear. METHODS A transgenic APP/PS1 mouse model of AD amyloidosis was used in this study. Behavioral tests were conducted to observe the protective effects of A2AR blockade on early spatial memory deficits in 4-month old APP/PS1 mice. To investigate the underlying synaptic mechanism of the protective effects of A2AR blockade, we further examined long-term potentiation (LTP) and network excitation/inhibition balance of dentate gyrus (DG) region, which is relevant to unique synaptic functions of immature adult-born granule cells (abGCs). Subsequently, the protective effects of A2AR blockade on dendritic morphology and synaptic plasticity of 6-week-old abGCs was investigated using retrovirus infection and electrophysiological recordings. The molecular mechanisms underlying neuroprotective properties of A2AR blockade on the synaptic plasticity of abGCs were further explored using molecular biology methods. RESULTS APP/PS1 mice displayed DG-dependent spatial memory deficits at an early stage. Additionally, impaired LTP and an imbalance in network excitation/inhibition were observed in the DG region of APP/PS1 mice, indicating synaptic structural and functional abnormalities of abGCs. A2AR was found to be upregulated in the hippocampus of the APP/PS1 mouse model of AD. Treatment with the selective A2AR antagonist SCH58261 for three weeks significantly ameliorated spatial memory deficits in APP/PS1 mice and markedly restored LTP and network excitation/inhibition balance in the DG region. Moreover, SCH58261 treatment restored dendritic morphology complexity and enhanced synaptic plasticity of abGCs in APP/PS1 mice. Furthermore, SCH58261 treatment alleviated the impairment of synaptic plasticity in abGCs. It achieved this by remodeling the subunit composition of NMDA receptors and increasing the proportion of NR2B receptors in abGCs of APP/PS1 mice. CONCLUSIONS Blockade of A2AR improves early spatial memory deficits in APP/PS1 mice, possibly by reversing synaptic defects of abGCs. This finding suggests that A2AR blockade could be a potential therapy for AD.
Collapse
Affiliation(s)
- Qi Ji
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
- College of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Yang Yang
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
- Department of Neurosurgery, The 904Th Hospital of PLA, Medical School of Anhui Medical University, Wuxi, 214044, Jiangsu, China
| | - Yun Xiong
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
- College of Basic Medicine, Army Medical University, Chongqing, 400038, China
| | - Ying-Jie Zhang
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
| | - Jun Jiang
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
| | - Li-Ping Zhou
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
| | - Xiao-Hui Du
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
| | - Chun-Xiang Wang
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China
| | - Zhi-Ru Zhu
- Department of Medical Psychology, Army Medical University, Gaotanyan Street 30, Chongqing, 400038, PR China.
| |
Collapse
|
21
|
Mugnaini M, Trinchero MF, Schinder AF, Piatti VC, Kropff E. Unique potential of immature adult-born neurons for the remodeling of CA3 spatial maps. Cell Rep 2023; 42:113086. [PMID: 37676761 DOI: 10.1016/j.celrep.2023.113086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/30/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
Mammalian hippocampal circuits undergo extensive remodeling through adult neurogenesis. While this process has been widely studied, the specific contribution of adult-born granule cells (aGCs) to spatial operations in the hippocampus remains unknown. Here, we show that optogenetic activation of 4-week-old (young) aGCs in free-foraging mice produces a non-reversible reconfiguration of spatial maps in proximal CA3 while rarely evoking neural activity. Stimulation of the same neuronal cohort on subsequent days recruits CA3 neurons with increased efficacy but fails to induce further remapping. In contrast, stimulation of 8-week-old (mature) aGCs can reliably activate CA3 cells but produces no alterations in spatial maps. Our results reveal a unique role of young aGCs in remodeling CA3 representations, a potential that can be depleted and is lost with maturation. This ability could contribute to generate orthogonalized downstream codes supporting pattern separation.
Collapse
Affiliation(s)
- Matías Mugnaini
- Department of Physiology, Molecular and Cellular Biology Dr. Héctor Maldonado, Faculty of Exact and Natural Science, University of Buenos Aires, Buenos Aires C1428EGA, Argentina; Laboratory of Physiology and Algorithms of the Brain, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina
| | - Mariela F Trinchero
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina
| | - Alejandro F Schinder
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
| | - Verónica C Piatti
- Laboratory of Neuronal Plasticity, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
| | - Emilio Kropff
- Laboratory of Physiology and Algorithms of the Brain, Leloir Institute (IIBBA-CONICET), Buenos Aires C1405BWE, Argentina.
| |
Collapse
|
22
|
Oddi S, Fiorenza MT, Maccarrone M. Endocannabinoid signaling in adult hippocampal neurogenesis: A mechanistic and integrated perspective. Prog Lipid Res 2023; 91:101239. [PMID: 37385352 DOI: 10.1016/j.plipres.2023.101239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 06/01/2023] [Accepted: 06/25/2023] [Indexed: 07/01/2023]
Abstract
Dentate gyrus of the hippocampus continuously gives rise to new neurons, namely, adult-born granule cells, which contribute to conferring plasticity to the mature brain throughout life. Within this neurogenic region, the fate and behavior of neural stem cells (NSCs) and their progeny result from a complex balance and integration of a variety of cell-autonomous and cell-to-cell-interaction signals and underlying pathways. Among these structurally and functionally diverse signals, there are endocannabinoids (eCBs), the main brain retrograde messengers. These pleiotropic bioactive lipids can directly and/or indirectly influence adult hippocampal neurogenesis (AHN) by modulating, both positively and negatively, multiple molecular and cellular processes in the hippocampal niche, depending on the cell type or stage of differentiation. Firstly, eCBs act directly as cell-intrinsic factors, cell-autonomously produced by NSCs following their stimulation. Secondly, in many, if not all, niche-associated cells, including some local neuronal and nonneuronal elements, the eCB system indirectly modulates the neurogenesis, linking neuronal and glial activity to regulating distinct stages of AHN. Herein, we discuss the crosstalk of the eCB system with other neurogenesis-relevant signal pathways and speculate how the hippocampus-dependent neurobehavioral effects elicited by (endo)cannabinergic medications are interpretable in light of the key regulatory role that eCBs play on AHN.
Collapse
Affiliation(s)
- Sergio Oddi
- Department of Veterinary Medicine, University of Teramo, Via R. Balzarini 1, 64100 Teramo, Italy; European Center for Brain Research/IRCCS Santa Lucia Foundation, Via del Fosso di Fiorano 64, 00143 Rome, Italy.
| | - Maria Teresa Fiorenza
- European Center for Brain Research/IRCCS Santa Lucia Foundation, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Department of Psychology, Division of Neuroscience and "Daniel Bovet" Neurobiology Research Center, Sapienza University of Rome, Via dei Sardi 70, 00185 Rome, Italy
| | - Mauro Maccarrone
- European Center for Brain Research/IRCCS Santa Lucia Foundation, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, Via Vetoio Snc, 67100 L'Aquila, Italy
| |
Collapse
|
23
|
Xiang G, Liu X, Wang J, Lu S, Yu M, Zhang Y, Sun B, Huang B, Lu XY, Li X, Zhang D. Peroxisome proliferator-activated receptor-α activation facilitates contextual fear extinction and modulates intrinsic excitability of dentate gyrus neurons. Transl Psychiatry 2023; 13:206. [PMID: 37322045 DOI: 10.1038/s41398-023-02496-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 05/06/2023] [Accepted: 05/30/2023] [Indexed: 06/17/2023] Open
Abstract
The dentate gyrus (DG) of the hippocampus encodes contextual information associated with fear, and cell activity in the DG is required for acquisition and extinction of contextual fear. However, the underlying molecular mechanisms are not fully understood. Here we show that mice deficient for peroxisome proliferator-activated receptor-α (PPARα) exhibited a slower rate of contextual fear extinction. Furthermore, selective deletion of PPARα in the DG attenuated, while activation of PPARα in the DG by local infusion of aspirin facilitated extinction of contextual fear. The intrinsic excitability of DG granule neurons was reduced by PPARα deficiency but increased by activation of PPARα with aspirin. Using RNA-Seq transcriptome we found that the transcription level of neuropeptide S receptor 1 (Npsr1) was tightly correlated with PPARα activation. Our results provide evidence that PPARα plays an important role in regulating DG neuronal excitability and contextual fear extinction.
Collapse
Affiliation(s)
- Guo Xiang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Xia Liu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Jiangong Wang
- Institute of Metabolic and Neuropsychiatric Disorders, Binzhou Medical University Hospital, Binzhou, 256600, China
| | - Shunshun Lu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Meng Yu
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
| | - Yuhan Zhang
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Bin Sun
- National Glycoengineering Research Center, Shandong University, Jinan, 250012, China
| | - Bin Huang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Xin-Yun Lu
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia at Augusta University, Augusta, GA, USA
| | - Xingang Li
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China
| | - Di Zhang
- Department of Neurosurgery, Qilu Hospital and Institute of Brain and Brain-Inspired Science, Shandong University, Jinan, 250012, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250012, China.
| |
Collapse
|
24
|
Li YD, Luo YJ, Xie L, Tart DS, Sheehy RN, Zhang L, Coleman LG, Chen X, Song J. Activation of hypothalamic-enhanced adult-born neurons restores cognitive and affective function in Alzheimer's disease. Cell Stem Cell 2023; 30:415-432.e6. [PMID: 37028406 PMCID: PMC10150940 DOI: 10.1016/j.stem.2023.02.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 12/29/2022] [Accepted: 02/14/2023] [Indexed: 04/09/2023]
Abstract
Patients with Alzheimer's disease (AD) exhibit progressive memory loss, depression, and anxiety, accompanied by impaired adult hippocampal neurogenesis (AHN). Whether AHN can be enhanced in impaired AD brain to restore cognitive and affective function remains elusive. Here, we report that patterned optogenetic stimulation of the hypothalamic supramammillary nucleus (SuM) enhances AHN in two distinct AD mouse models, 5×FAD and 3×Tg-AD. Strikingly, the chemogenetic activation of SuM-enhanced adult-born neurons (ABNs) rescues memory and emotion deficits in these AD mice. By contrast, SuM stimulation alone or activation of ABNs without SuM modification fails to restore behavioral deficits. Furthermore, quantitative phosphoproteomics analyses reveal activation of the canonical pathways related to synaptic plasticity and microglia phagocytosis of plaques following acute chemogenetic activation of SuM-enhanced (vs. control) ABNs. Our study establishes the activity-dependent contribution of SuM-enhanced ABNs in modulating AD-related deficits and informs signaling mechanisms mediated by the activation of SuM-enhanced ABNs.
Collapse
Affiliation(s)
- Ya-Dong Li
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Yan-Jia Luo
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ling Xie
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Dalton S Tart
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ryan N Sheehy
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Pharmacology Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Libo Zhang
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Leon G Coleman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Xian Chen
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Juan Song
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
25
|
Ávila-Gámiz F, Pérez-Cano A, Pérez-Berlanga J, Mullor-Vigo R, Zambrana-Infantes E, Santín L, Ladrón de Guevara-Miranda D. Sequential treadmill exercise and cognitive training synergistically increase adult hippocampal neurogenesis in mice. Physiol Behav 2023; 266:114184. [PMID: 37030425 DOI: 10.1016/j.physbeh.2023.114184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/26/2023] [Accepted: 04/04/2023] [Indexed: 04/09/2023]
Abstract
Combining physical and cognitive training has been suggested to promote further benefits on brain and cognition, which could include synergistic improvement of hippocampal neuroplasticity. In this paper, we investigated whether treadmill exercise followed by a working memory training in the water maze increase adult hippocampal neurogenesis to a greater extent than either treatment alone. Our results revealed that ten days of scheduled running enhance cell proliferation/survival in the short-term as well as performance in the water maze. Moreover, exercised mice that received working memory training displayed more surviving dentate granule cells compared to those untreated or subjected to only one of the treatments. According to these findings, we suggest that combining physical and cognitive stimulation yield synergic effects on adult hippocampal neurogenesis by extending the pool of newly-born cells and subsequently favouring their survival. Future research could take advantage from this non-invasive, multimodal approach to achieve substantial and longer-lasting enhancement in adult hippocampal neurogenesis, which might be relevant for improving cognition in healthy or neurologically impaired conditions.
Collapse
|
26
|
Groisman AI, Aguilar-Arredondo A, Giacomini D, Schinder AF. Neuroligin-2 controls the establishment of fast GABAergic transmission in adult-born granule cells. Hippocampus 2023; 33:424-441. [PMID: 36709408 DOI: 10.1002/hipo.23505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 12/19/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023]
Abstract
GABAergic inhibition is critical for the precision of neuronal spiking and the homeostatic regulation of network activity in the brain. Adult neurogenesis challenges network homeostasis because new granule cells (GCs) integrate continuously in the functional dentate gyrus. While developing, adult-born GCs undergo a transient state of enhanced excitability due to the delayed maturation of perisomatic GABAergic inhibition by parvalbumin interneurons (PV-INs). The mechanisms underlying this delayed synaptic maturation remain unknown. We examined the morphology and function of synapses formed by PV-INs onto new GCs over a 2-month interval in young adult mice, and investigated the influence of the synaptic adhesion molecule neuroligin-2 (NL2). Perisomatic appositions of PV-IN terminals onto new GCs were conspicuous at 2 weeks and continued to grow in size to reach a plateau over the fourth week. Postsynaptic knockdown of NL2 by expression of a short-hairpin RNA (shNL2) in new GCs resulted in smaller size of synaptic contacts, reduced area of perisomatic appositions of the vesicular GABA transporter VGAT, and the number of presynaptic active sites. GCs expressing shNL2 displayed spontaneous GABAergic responses with decreased frequency and amplitude, as well as slower kinetics compared to control GCs. In addition, postsynaptic responses evoked by optogenetic stimulation of PV-INs exhibited slow kinetics, increased paired-pulse ratio and coefficient of variation in GCs with NL2 knockdown, suggesting a reduction in the number of active synapses as well as in the probability of neurotransmitter release (Pr ). Our results demonstrate that synapses formed by PV-INs on adult-born GCs continue to develop beyond the point of anatomical growth, and require NL2 for the structural and functional maturation that accompanies the conversion into fast GABAergic transmission.
Collapse
Affiliation(s)
- Ayelén I Groisman
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | | | - Damiana Giacomini
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| | - Alejandro F Schinder
- Laboratorio de Plasticidad Neuronal, Fundación Instituto Leloir, Buenos Aires, Argentina
| |
Collapse
|
27
|
Parylak SL, Qiu F, Linker SB, Gallina IS, Lim CK, Preciado D, McDonald AH, Zhou X, Gage FH. Neuronal activity-related transcription is blunted in immature compared to mature dentate granule cells. Hippocampus 2023; 33:412-423. [PMID: 36811254 PMCID: PMC10985790 DOI: 10.1002/hipo.23515] [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: 09/26/2022] [Revised: 02/01/2023] [Accepted: 02/07/2023] [Indexed: 02/24/2023]
Abstract
Immature dentate granule cells (DGCs) generated in the hippocampus during adulthood are believed to play a unique role in dentate gyrus (DG) function. Although immature DGCs have hyperexcitable membrane properties in vitro, the consequences of this hyperexcitability in vivo remain unclear. In particular, the relationship between experiences that activate the DG, such as exploration of a novel environment (NE), and downstream molecular processes that modify DG circuitry in response to cellular activation is unknown in this cell population. We first performed quantification of immediate early gene (IEG) proteins in immature (5-week-old) and mature (13-week-old) DGCs from mice exposed to a NE. Paradoxically, we observed lower IEG protein expression in hyperexcitable immature DGCs. We then isolated nuclei from active and inactive immature DGCs and performed single-nuclei RNA-Sequencing. Compared to mature nuclei collected from the same animal, immature DGC nuclei showed less activity-induced transcriptional change, even though they were classified as active based on expression of ARC protein. These results demonstrate that the coupling of spatial exploration, cellular activation, and transcriptional change differs between immature and mature DGCs, with blunted activity-induced changes in immature cells.
Collapse
Affiliation(s)
- Sarah L Parylak
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Fan Qiu
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Sara B Linker
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Iryna S Gallina
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Christina K Lim
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - David Preciado
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Aidan H McDonald
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Xavier Zhou
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| | - Fred H Gage
- Laboratory of Genetics, The Salk Institute for Biological Studies, La Jolla, California, USA
| |
Collapse
|
28
|
Li YD, Luo YJ, Song J. Optimizing memory performance and emotional states: multi-level enhancement of adult hippocampal neurogenesis. Curr Opin Neurobiol 2023; 79:102693. [PMID: 36822141 PMCID: PMC10023407 DOI: 10.1016/j.conb.2023.102693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 01/03/2023] [Accepted: 01/12/2023] [Indexed: 02/25/2023]
Abstract
Adult hippocampal neurogenesis (AHN) plays a key role in modulating memory and emotion processing. A fundamental question remains on how to effectively modulate AHN to improve hippocampal function. Here, we review recent work on how distinct aspects of hippocampal neurogenesis, including the number, maturation state, and activity of adult-born neurons (ABNs), contribute to overall hippocampal function. We propose multi-level enhancement of hippocampal neurogenesis with the combination of increased number, elevated activity, and enhanced maturation of ABNs as a potential strategy to optimize overall hippocampal performance. In addition, integration of ABNs induces significant remodeling of the local hippocampal circuits, which may in turn modulates brain-wide network dynamics. We discuss recent progress on how integration of ABNs contributes to local hippocampal circuit and brain-wide network dynamics during behavior.
Collapse
Affiliation(s)
- Ya-Dong Li
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. https://twitter.com/yadlee2
| | - Yan-Jia Luo
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Juan Song
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| |
Collapse
|
29
|
Kitchigina V, Shubina L. Oscillations in the dentate gyrus as a tool for the performance of the hippocampal functions: Healthy and epileptic brain. Prog Neuropsychopharmacol Biol Psychiatry 2023; 125:110759. [PMID: 37003419 DOI: 10.1016/j.pnpbp.2023.110759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/17/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
The dentate gyrus (DG) is part of the hippocampal formation and is essential for important cognitive processes such as navigation and memory. The oscillatory activity of the DG network is believed to play a critical role in cognition. DG circuits generate theta, beta, and gamma rhythms, which participate in the specific information processing performed by DG neurons. In the temporal lobe epilepsy (TLE), cognitive abilities are impaired, which may be due to drastic alterations in the DG structure and network activity during epileptogenesis. The theta rhythm and theta coherence are especially vulnerable in dentate circuits; disturbances in DG theta oscillations and their coherence may be responsible for general cognitive impairments observed during epileptogenesis. Some researchers suggested that the vulnerability of DG mossy cells is a key factor in the genesis of TLE, but others did not support this hypothesis. The aim of the review is not only to present the current state of the art in this field of research but to help pave the way for future investigations by highlighting the gaps in our knowledge to completely appreciate the role of DG rhythms in brain functions. Disturbances in oscillatory activity of the DG during TLE development may be a diagnostic marker in the treatment of this disease.
Collapse
Affiliation(s)
- Valentina Kitchigina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia.
| | - Liubov Shubina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow region 142290, Russia
| |
Collapse
|
30
|
Vyleta NP, Snyder JS. Enhanced excitability but mature action potential waveforms at mossy fiber terminals of young, adult-born hippocampal neurons in mice. Commun Biol 2023; 6:290. [PMID: 36934174 PMCID: PMC10024705 DOI: 10.1038/s42003-023-04678-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 03/07/2023] [Indexed: 03/20/2023] Open
Abstract
Adult-born granule neurons pass through immature critical periods where they display enhanced somatic excitability and afferent plasticity, which is believed to endow them with unique roles in hippocampal learning and memory. Using patch clamp recordings in mouse hippocampal slices, here we show that young neuron hyper-excitability is also observed at presynaptic mossy fiber terminals onto CA3 pyramidal neurons. However, action potential waveforms mature faster in the bouton than in the soma, suggesting rapid efferent functionality during immature stages.
Collapse
Affiliation(s)
- Nicholas P Vyleta
- Department of Psychology, Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, BC, Canada
| | - Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Center for Brain Health, University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
31
|
Saffar Shahroudi A, Hashemikamangar SS, Ahmed Aljawad ZA, Behniafar B. Dental students' knowledge about protective guidelines for clinical practice during the COVID-19 pandemic. J Oral Biol Craniofac Res 2023; 13:327-331. [PMID: 36915295 PMCID: PMC9990523 DOI: 10.1016/j.jobcr.2023.02.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 01/21/2023] [Accepted: 02/20/2023] [Indexed: 03/09/2023] Open
Abstract
Objective The coronavirus disease 2019 (COVID-19) originated in China, in December 2019, spread worldwide promptly and turned into an outbreak which caused an international public health concern. The novel coronavirus which is also called SARS-CoV-2 transmits predominantly by respiratory droplets and the spread pattern of this infection throughout the community became a big challenge encountering the dental profession. Recently several guidelines have been developed for dental clinicians to protect both patients and practitioners, agents this infection. The aim of this study was to estimate the knowledge of dental students about the content of protective guidelines for clinical practice during the COVID-19 pandemic. Methods An online questionnaire was developed by a team of specialists which were the faculty member of Tehran University of Medical sciences according to the content of the protective guidelines of ADA for dental practice during the COVID-19 pandemic. The questionnaire was validated and its reliability was confirmed by retesting 10 samples after 2 weeks with a cronbach alpha of 0.9. The online questionnaire was sent to 4 dental schools in the city of Tehran and was fill out by 170 dental students. Results The mean knowledge score for all 170 participants was 16.23 out of 32 (50.72%) with the maximum score of 24 (75.0%) and the minimum score of 1 (3.1%). There was a significant relationship between the gender of participants and their knowledge score (p = 0.032) in the way that male students had significantly higher score than females. Students with more advanced educational level achieved higher knowledge scores. (p = 0.038) However, there were no significant correlation between other variables and the students' knowledge score. (p > 0.05). Conclusion Dental students had acceptable knowledge about the general protocols against corona virus in terms of hand hygiene, wearing face masks, surface sanitization and diagnostic symptoms of a patient susceptible to be infected by corona virus. However, mostly they were not aware of the details of the guideline's items which makes it crucial to add related content in the dental students' educational curriculum.
Collapse
Affiliation(s)
- Atefe Saffar Shahroudi
- Dental Research Center, Dentistry Research Institute, Department of Orthodontics, Dental School, Tehran University of Medical Sciences, Tehran, Iran
| | - Sedighe-Sadat Hashemikamangar
- Department of Operative Dentistry, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran
| | | | - Behnaz Behniafar
- Department of Operative Dentistry, Dental School, Tehran University of Medical Sciences, International Campus, Tehran, Iran
| |
Collapse
|
32
|
The times they are a-changin': a proposal on how brain flexibility goes beyond the obvious to include the concepts of "upward" and "downward" to neuroplasticity. Mol Psychiatry 2023; 28:977-992. [PMID: 36575306 PMCID: PMC10005965 DOI: 10.1038/s41380-022-01931-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 12/07/2022] [Accepted: 12/14/2022] [Indexed: 12/28/2022]
Abstract
Since the brain was found to be somehow flexible, plastic, researchers worldwide have been trying to comprehend its fundamentals to better understand the brain itself, make predictions, disentangle the neurobiology of brain diseases, and finally propose up-to-date treatments. Neuroplasticity is simple as a concept, but extremely complex when it comes to its mechanisms. This review aims to bring to light an aspect about neuroplasticity that is often not given enough attention as it should, the fact that the brain's ability to change would include its ability to disconnect synapses. So, neuronal shrinkage, decrease in spine density or dendritic complexity should be included within the concept of neuroplasticity as part of its mechanisms, not as an impairment of it. To that end, we extensively describe a variety of studies involving topics such as neurodevelopment, aging, stress, memory and homeostatic plasticity to highlight how the weakening and disconnection of synapses organically permeate the brain in so many ways as a good practice of its intrinsic physiology. Therefore, we propose to break down neuroplasticity into two sub-concepts, "upward neuroplasticity" for changes related to synaptic construction and "downward neuroplasticity" for changes related to synaptic deconstruction. With these sub-concepts, neuroplasticity could be better understood from a bigger landscape as a vector in which both directions could be taken for the brain to flexibly adapt to certain demands. Such a paradigm shift would allow a better understanding of the concept of neuroplasticity to avoid any data interpretation bias, once it makes clear that there is no morality with regard to the organic and physiological changes that involve dynamic biological systems as seen in the brain.
Collapse
|
33
|
Inoue R, Ni X, Mori H. Blockade of D-serine signaling and adult hippocampal neurogenesis attenuates remote contextual fear memory following multiple memory retrievals in male mice. Front Neurosci 2023; 16:1030702. [PMID: 36685240 PMCID: PMC9845639 DOI: 10.3389/fnins.2022.1030702] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 12/06/2022] [Indexed: 01/06/2023] Open
Abstract
The retrieval of fear memories induces two opposing processes, reconsolidation, and extinction. The memory reconsolidation is an active process that involves gene expression and updates an existing memory. It is hypothesized that blockade of reconsolidation by manipulating the neurobiological factors, which are mechanistically involved in the process, could weaken or disrupt the original fear memory. The N-methyl-D-aspartate (NMDA) receptor and hippocampal neurogenesis play crucial roles in hippocampus-dependent memory processes, including reconsolidation. Using contextual fear conditioning paradigm with multiple retrievals, we attempted to weaken the original contextual fear memory by repeatedly disrupting retrieval-induced reconsolidation via downregulation of NMDA receptor signaling and inhibition of neurogenesis. In the first experiment, prior to fear conditioning, NMDA receptor signaling was downregulated by the genetic reduction of its co-agonist, D-serine, and the neurogenesis was dampened by focal X-ray irradiation on the hippocampus. We found that simultaneous D-serine reduction and neurogenesis dampening resulted in a progressive decrease in freezing following each retrieval, leading to an attenuation of remote contextual fear memory on day 28. In the second experiment using the same behavioral protocols, after conditioning, pharmacological approaches were conducted to simultaneously block D-serine signaling and neurogenesis, resulting in a similar suppressive effect on the remote fear memory. The present findings provide insights for understanding the role of D-serine-mediated NMDA receptor signaling and neurogenesis in memory retrieval and the maintenance of remote fear memory, and improving the efficacy of exposure-based therapy for the treatment of post-traumatic stress disorder (PTSD).
Collapse
Affiliation(s)
- Ran Inoue
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
| | - Xiance Ni
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Graduate School of Innovative Life Science, University of Toyama, Toyama, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Faculty of Medicine, University of Toyama, Toyama, Japan,Research Center for Idling Brain Science, University of Toyama, Toyama, Japan,*Correspondence: Hisashi Mori,
| |
Collapse
|
34
|
Zhang TR, Askari B, Kesici A, Guilherme E, Vila-Rodriguez F, Snyder JS. Intermittent theta burst transcranial magnetic stimulation induces hippocampal mossy fibre plasticity in male but not female mice. Eur J Neurosci 2023; 57:310-323. [PMID: 36484786 DOI: 10.1111/ejn.15891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/12/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022]
Abstract
Transcranial magnetic stimulation (TMS) induces electric fields that depolarise or hyperpolarise neurons. Intermittent theta burst stimulation (iTBS), a patterned form of TMS that is delivered at the theta frequency (~5 Hz), induces neuroplasticity in the hippocampus, a brain region that is implicated in memory and learning. One form of plasticity that is unique to the hippocampus is adult neurogenesis; however, little is known about whether TMS or iTBS in particular affects newborn neurons. Here, we therefore applied repeated sessions of iTBS to male and female mice and measured the extent of adult neurogenesis and the morphological features of immature neurons. We found that repeated sessions of iTBS did not significantly increase the amount of neurogenesis or affect the gross dendritic morphology of new neurons, and there were no sex differences in neurogenesis rates or aspects of afferent morphology. In contrast, efferent properties of newborn neurons varied as a function of sex and stimulation. Chronic iTBS increased the size of mossy fibre terminals, which synapse onto Cornu Ammonis 3 (CA3) pyramidal neurons, but only in males. iTBS also increased the number of terminal-associated filopodia, putative synapses onto inhibitory interneurons but only in male mice. This efferent plasticity could result from a general trophic effect, or it could reflect accelerated maturation of immature neurons. Given the important role of mossy fibre synapses in hippocampal learning, our results identify a neurobiological effect of iTBS that might be associated with sex-specific changes in cognition.
Collapse
Affiliation(s)
- Tian Rui Zhang
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
- Non-Invasive Neurostimulation Therapies Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Baran Askari
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aydan Kesici
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Evelyn Guilherme
- Department of Physiotherapy, Federal University of Sao Carlos, Sao Carlo, Brazil
| | - Fidel Vila-Rodriguez
- Non-Invasive Neurostimulation Therapies Laboratory, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jason S Snyder
- Department of Psychology, Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
35
|
Fölsz O, Trouche S, Croset V. Adult-born neurons add flexibility to hippocampal memories. Front Neurosci 2023; 17:1128623. [PMID: 36875670 PMCID: PMC9975346 DOI: 10.3389/fnins.2023.1128623] [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: 12/20/2022] [Accepted: 01/30/2023] [Indexed: 02/17/2023] Open
Abstract
Although most neurons are generated embryonically, neurogenesis is maintained at low rates in specific brain areas throughout adulthood, including the dentate gyrus of the mammalian hippocampus. Episodic-like memories encoded in the hippocampus require the dentate gyrus to decorrelate similar experiences by generating distinct neuronal representations from overlapping inputs (pattern separation). Adult-born neurons integrating into the dentate gyrus circuit compete with resident mature cells for neuronal inputs and outputs, and recruit inhibitory circuits to limit hippocampal activity. They display transient hyperexcitability and hyperplasticity during maturation, making them more likely to be recruited by any given experience. Behavioral evidence suggests that adult-born neurons support pattern separation in the rodent dentate gyrus during encoding, and they have been proposed to provide a temporal stamp to memories encoded in close succession. The constant addition of neurons gradually degrades old connections, promoting generalization and ultimately forgetting of remote memories in the hippocampus. This makes space for new memories, preventing saturation and interference. Overall, a small population of adult-born neurons appears to make a unique contribution to hippocampal information encoding and removal. Although several inconsistencies regarding the functional relevance of neurogenesis remain, in this review we argue that immature neurons confer a unique form of transience on the dentate gyrus that complements synaptic plasticity to help animals flexibly adapt to changing environments.
Collapse
Affiliation(s)
- Orsolya Fölsz
- Department of Biosciences, Durham University, Durham, United Kingdom.,MSc in Neuroscience Programme, University of Oxford, Oxford, United Kingdom
| | - Stéphanie Trouche
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Vincent Croset
- Department of Biosciences, Durham University, Durham, United Kingdom
| |
Collapse
|
36
|
Adult-born dentate granule cells promote hippocampal population sparsity. Nat Neurosci 2022; 25:1481-1491. [PMID: 36216999 PMCID: PMC9630129 DOI: 10.1038/s41593-022-01176-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 09/01/2022] [Indexed: 01/13/2023]
Abstract
The dentate gyrus (DG) gates neocortical information flow to the hippocampus. Intriguingly, the DG also produces adult-born dentate granule cells (abDGCs) throughout the lifespan, but their contribution to downstream firing dynamics remains unclear. Here, we show that abDGCs promote sparser hippocampal population spiking during mnemonic processing of novel stimuli. By combining triple-(DG-CA3-CA1) ensemble recordings and optogenetic interventions in behaving mice, we show that abDGCs constitute a subset of high-firing-rate neurons with enhanced activity responses to novelty and strong modulation by theta oscillations. Selectively activating abDGCs in their 4-7-week post-birth period increases sparsity of hippocampal population patterns, whereas suppressing abDGCs reduces this sparsity, increases principal cell firing rates and impairs novel object recognition with reduced dimensionality of the network firing structure, without affecting single-neuron spatial representations. We propose that adult-born granule cells transiently support sparser hippocampal population activity structure for higher-dimensional responses relevant to effective mnemonic information processing.
Collapse
|
37
|
Castro AE, Domínguez-Ordoñez R, Young LJ, Camacho FJ, Ávila-González D, Paredes RG, Díaz NF, Portillo W. Pair-bonding and social experience modulate new neurons survival in adult male and female prairie voles (Microtus ochrogaster). Front Neuroanat 2022; 16:987229. [PMID: 36189119 PMCID: PMC9520527 DOI: 10.3389/fnana.2022.987229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/16/2022] [Indexed: 12/04/2022] Open
Abstract
Prairie voles are a socially monogamous species that, after cohabitation with mating, form enduring pair bonds. The plastic mechanisms involved in this social behavior are not well-understood. Neurogenesis in adult rodents is a plastic neural process induced in specific brain areas like the olfactory bulbs (OB) and dentate gyrus (DG) of the hippocampus. However, it is unknown how cell survival is modulated by social or sexual experience in prairie voles. This study aimed to evaluate if cohabitation with mating and/or social exposure to a vole of the opposite sex increased the survival of the new cells in the main and accessory OB and DG. To identify the new cells and evaluate their survival, voles were injected with the DNA synthesis marker 5-bromo-2’-deoxyuridine (BrdU) and were randomly distributed into one of the following groups: (A) Control (C), voles that did not receive any sexual stimulation and were placed alone during the behavioral test. (B) Social exposure (SE), voles were individually placed in a cage equally divided into two compartments by an acrylic screen with small holes. One male and one female were placed in opposite compartments. (C) Social cohabitation with mating (SCM), animals mated freely. Our findings demonstrated that SCM females had increases in the number of new cells (BrdU-positive cells) in the main olfactory bulb and new mature neurons (BrdU/NeuN-positive cells) in the glomerular layer (GlL). In contrast, these new cells decrease in males in the SE and SCM conditions. In the granular cell layer (GrL), SCM females had more new cells and neurons than the SE group. In the accessory olfactory bulb, in the anterior GlL, SCM decreased the number of new cells and neurons in females. On the other hand, in the DG, SCM and SE increase the number of new cells in the suprapyramidal blade in female voles. Males from SCM express more new cells and neurons in the infrapyramidal blade compared with SE group. Comparison between male and females showed that new cells/neurons survival was sex dependent. These results suggest that social interaction and sexual behavior modulate cell survival and influence the neuronal fate in a sex-dependent manner, in the OB and DG. This study will contribute to understand neural mechanisms of complex social and pair bond behaviors in the prairie voles; supporting adult neurogenesis as a plastic mechanism potentially involved in social monogamous strategy.
Collapse
Affiliation(s)
- Analía E. Castro
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Raymundo Domínguez-Ordoñez
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
- Benemérita Universidad Autónoma de Puebla, Complejo Regional Centro, Puebla, Mexico
| | - Larry J. Young
- Silvio O. Conte Center for Oxytocin and Social Cognition, Center for Translational Social Neuroscience, Department of Psychiatry and Behavioral Sciences, Emory National Primate Research Center, Emory University, Atlanta, GA, United States
| | - Francisco J. Camacho
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Daniela Ávila-González
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Raúl G. Paredes
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
- Escuela Nacional de Estudios Superiores, Unidad Juriquilla, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Nestor F. Díaz
- Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Mexico City, Mexico
- *Correspondence: Nestor F. Díaz,
| | - Wendy Portillo
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
- Wendy Portillo,
| |
Collapse
|
38
|
Jedlicka P, Tomko M, Robins A, Abraham WC. Contributions by metaplasticity to solving the Catastrophic Forgetting Problem. Trends Neurosci 2022; 45:656-666. [PMID: 35798611 DOI: 10.1016/j.tins.2022.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 06/06/2022] [Accepted: 06/09/2022] [Indexed: 10/17/2022]
Abstract
Catastrophic forgetting (CF) refers to the sudden and severe loss of prior information in learning systems when acquiring new information. CF has been an Achilles heel of standard artificial neural networks (ANNs) when learning multiple tasks sequentially. The brain, by contrast, has solved this problem during evolution. Modellers now use a variety of strategies to overcome CF, many of which have parallels to cellular and circuit functions in the brain. One common strategy, based on metaplasticity phenomena, controls the future rate of change at key connections to help retain previously learned information. However, the metaplasticity properties so far used are only a subset of those existing in neurobiology. We propose that as models become more sophisticated, there could be value in drawing on a richer set of metaplasticity rules, especially when promoting continual learning in agents moving about the environment.
Collapse
Affiliation(s)
- Peter Jedlicka
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, Giessen, Germany; Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, Frankfurt/Main, Germany; Frankfurt Institute for Advanced Studies, Frankfurt 60438, Germany.
| | - Matus Tomko
- ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Faculty of Medicine, Justus Liebig University, Giessen, Germany; Institute of Molecular Physiology and Genetics, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, Slovakia
| | - Anthony Robins
- Department of Computer Science, University of Otago, Dunedin 9016, New Zealand
| | - Wickliffe C Abraham
- Department of Psychology, Brain Health Research Centre, University of Otago, Dunedin 9054, New Zealand.
| |
Collapse
|
39
|
Segi-Nishida E, Suzuki K. Regulation of adult-born and mature neurons in stress response and antidepressant action in the dentate gyrus of the hippocampus. Neurosci Res 2022:S0168-0102(22)00233-4. [PMID: 36030966 DOI: 10.1016/j.neures.2022.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022]
Abstract
The dentate gyrus (DG) of the hippocampus has been implicated in the regulation of stress responses, and in the pathophysiology and treatment of depression. This review discusses the cellular changes caused by chronic stress and the cellular role of the DG in stress-induced behavioral changes and its antidepressant-like effects. Regarding adult-born neurogenic processes in the DG, chronic stress, such as repeated social defeat, suppresses cell proliferation during and immediately after stress; however, this effect is transient. The subsequent differentiation and survival processes are differentially regulated depending on the timing and sensitivity of stress. The activation of young adult-born neurons during stress contributes to stress resilience, while the transient increase in the survival of adult-born neurons after the cessation of stress seems to promote stress susceptibility. In mature granule neurons, the predominant cells in the DG, synaptic plasticity is suppressed by chronic stress. However, a group of mature granule neurons is activated by chronic stress. Chronic antidepressant treatment can transform mature granule neurons to a phenotype resembling that of immature neurons, characterized as "dematuration". Adult-born neurons suppress the activation of mature granule neurons during stress, indicating that local neural interactions within the DG are important for the stress response. Elucidating the stress-associated context- and timing-dependent cellular changes and functions in the DG will provide insights into stress-related psychiatric diseases.
Collapse
Affiliation(s)
- Eri Segi-Nishida
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo, Japan.
| | - Kanzo Suzuki
- Department of Biological Science and Technology, Faculty of Advanced Engineering, Tokyo University of Science, 6-3-1 Niijuku, Katsushika-ku, Tokyo, Japan
| |
Collapse
|
40
|
Melatonin Attenuates Methotrexate-Induced Reduction of Antioxidant Activity Related to Decreases of Neurogenesis in Adult Rat Hippocampus and Prefrontal Cortex. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:1596362. [PMID: 35873801 PMCID: PMC9307408 DOI: 10.1155/2022/1596362] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 07/01/2022] [Indexed: 01/19/2023]
Abstract
Previous studies have revealed that the side effects of anticancer drugs induce a decrease of neurogenesis. Methotrexate (MTX), one of anticancer drugs, can induce lipid peroxidation as an indicator of oxidative stress in the brain. Melatonin has been presented as an antioxidant that can prevent oxidative stress-induced neuronal damage via the activation of antioxidant enzymes associated with the increase of neurogenesis. The aims of the present study are to examine the neuroprotective effect of melatonin on the neurotoxicity of MTX on neurogenesis and the changes of protein expression and antioxidant enzyme levels in adult rat hippocampus and prefrontal cortex (PFC). Male Sprague-Dawley rats were assigned into four groups: vehicle, MTX, melatonin, and melatonin+MTX groups. The vehicle group received saline solution and 10% ethanol solution, whereas the experimental groups received MTX (75 mg/kg, i.v.) and melatonin (8 mg/kg, i.p.) treatments. After the animal examination, the brains were removed for p21 immunofluorescence staining. The hippocampus and PFC were harvested for Western blot analysis and biochemical assessments of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD). The immunofluorescence result showed that coadministration with melatonin diminished p21-positive cells in the hippocampal dentate gyrus, indicating a decrease of cell cycle arrest. Melatonin reduced the levels of MDA and prevented the decline of antioxidant enzyme activities in rats receiving MTX. In the melatonin+MTX group, the protein expression results showed that melatonin treatment significantly upregulated synaptic plasticity and an immature neuron marker through enhancing brain derived neurotrophic factor (BDNF) and doublecortin (DCX), respectively. Moreover, melatonin ameliorated the antioxidant defense system by improving the nuclear factor erythroid 2-related factor 2 (Nrf2) in rats receiving MTX. These findings suggested that the effects of melatonin can ameliorate MTX toxicity by several mechanisms, including an increase of endogenous antioxidants and neurogenesis in adult rat hippocampus and PFC.
Collapse
|
41
|
Molecular landscapes of human hippocampal immature neurons across lifespan. Nature 2022; 607:527-533. [PMID: 35794479 PMCID: PMC9316413 DOI: 10.1038/s41586-022-04912-w] [Citation(s) in RCA: 100] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 05/26/2022] [Indexed: 01/18/2023]
Abstract
Immature dentate granule cells (imGCs) arising from adult hippocampal neurogenesis contribute to plasticity and unique brain functions in rodents1,2 and are dysregulated in multiple human neurological disorders3-5. Little is known about the molecular characteristics of adult human hippocampal imGCs, and even their existence is under debate1,6-8. Here we performed single-nucleus RNA sequencing aided by a validated machine learning-based analytic approach to identify imGCs and quantify their abundance in the human hippocampus at different stages across the lifespan. We identified common molecular hallmarks of human imGCs across the lifespan and observed age-dependent transcriptional dynamics in human imGCs that suggest changes in cellular functionality, niche interactions and disease relevance, that differ from those in mice9. We also found a decreased number of imGCs with altered gene expression in Alzheimer's disease. Finally, we demonstrated the capacity for neurogenesis in the adult human hippocampus with the presence of rare dentate granule cell fate-specific proliferating neural progenitors and with cultured surgical specimens. Together, our findings suggest the presence of a substantial number of imGCs in the adult human hippocampus via low-frequency de novo generation and protracted maturation, and our study reveals their molecular properties across the lifespan and in Alzheimer's disease.
Collapse
|
42
|
Lattanzi D, Savelli D, Pagliarini M, Cuppini R, Ambrogini P. Short-Term, Voluntary Exercise Affects Morpho-Functional Maturation of Adult-Generated Neurons in Rat Hippocampus. Int J Mol Sci 2022; 23:ijms23126866. [PMID: 35743307 PMCID: PMC9224999 DOI: 10.3390/ijms23126866] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/17/2022] [Accepted: 06/18/2022] [Indexed: 02/01/2023] Open
Abstract
Physical exercise is a well-proven neurogenic stimulus, promoting neuronal progenitor proliferation and affecting newborn cell survival. Besides, it has beneficial effects on brain health and cognition. Previously, we found that three days of physical activity in a very precocious period of adult-generated granule cell life is able to antedate the appearance of the first GABAergic synaptic contacts and increase T-type Ca2+ channel expression. Considering the role of GABA and Ca2+ in fostering neuronal maturation, in this study, we used short-term, voluntary exercise on a running wheel to investigate if it is able to induce long-term morphological and synaptic changes in newborn neurons. Using adult male rats, we found that: (i) three days of voluntary physical exercise can definitively influence the morpho-functional maturation process of newborn granule neurons when applied very early during their development; (ii) a significant percentage of new neurons show more mature morphological characteristics far from the end of exercise protocol; (iii) the long-term morphological effects result in enhanced synaptic plasticity. Present findings demonstrate that the morpho-functional changes induced by exercise on very immature adult-generated neurons are permanent, affecting the neuron maturation and integration in hippocampal circuitry. Our data contribute to underpinning the beneficial potential of physical activity on brain health, also performed for short times.
Collapse
|
43
|
Mazzitelli-Fuentes LS, Román FR, Castillo Elías JR, Deleglise EB, Mongiat LA. Spatial Learning Promotes Adult Neurogenesis in Specific Regions of the Zebrafish Pallium. Front Cell Dev Biol 2022; 10:840964. [PMID: 35646912 PMCID: PMC9130729 DOI: 10.3389/fcell.2022.840964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 03/29/2022] [Indexed: 11/13/2022] Open
Abstract
Adult neurogenesis could be considered as a homeostatic mechanism that accompanies the continuous growth of teleost fish. As an alternative but not excluding hypothesis, adult neurogenesis would provide a form of plasticity necessary to adapt the brain to environmental challenges. The zebrafish pallium is a brain structure involved in the processing of various cognitive functions and exhibits extended neurogenic niches throughout the periventricular zone. The involvement of neuronal addition as a learning-related plastic mechanism has not been explored in this model, yet. In this work, we trained adult zebrafish in a spatial behavioral paradigm and evaluated the neurogenic dynamics in different pallial niches. We found that adult zebrafish improved their performance in a cue-guided rhomboid maze throughout five daily sessions, being the fish able to relearn the task after a rule change. This cognitive activity increased cell proliferation exclusively in two pallial regions: the caudal lateral pallium (cLP) and the rostral medial pallium (rMP). To assessed whether learning impinges on pallial adult neurogenesis, mitotic cells were labeled by BrdU administration, and then fish were trained at different periods of adult-born neuron maturation. Our results indicate that adult-born neurons are being produced on demand in rMP and cLP during the learning process, but with distinct critical periods among these regions. Next, we evaluated the time course of adult neurogenesis by pulse and chase experiments. We found that labeled cells decreased between 4 and 32 dpl in both learning-sensitive regions, whereas a fraction of them continues proliferating over time. By modeling the population dynamics of neural stem cells (NSC), we propose that learning increases adult neurogenesis by two mechanisms: driving a chained proliferation of labeled NSC and rescuing newborn neurons from death. Our findings highlight adult neurogenesis as a conserved source of brain plasticity and shed light on a rostro-caudal specialization of pallial neurogenic niches in adult zebrafish.
Collapse
Affiliation(s)
- Laura S Mazzitelli-Fuentes
- Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.,Consejo Nacional de Investigaciones Científicas y, Técnicas, Argentina.,Instituto Balseiro, Centro Atómico Bariloche, San Carlos de Bariloche, Argentina
| | - Fernanda R Román
- Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.,Consejo Nacional de Investigaciones Científicas y, Técnicas, Argentina.,Centro Regional Universitario Bariloche, Universidad Nacional del Comahue, San Carlos de Bariloche, Argentina
| | - Julio R Castillo Elías
- Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.,Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Emilia B Deleglise
- Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.,Consejo Nacional de Investigaciones Científicas y, Técnicas, Argentina.,Instituto Balseiro, Centro Atómico Bariloche, San Carlos de Bariloche, Argentina
| | - Lucas A Mongiat
- Departamento de Física Médica, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, San Carlos de Bariloche, Argentina.,Consejo Nacional de Investigaciones Científicas y, Técnicas, Argentina
| |
Collapse
|
44
|
Galanin and Neuropeptide Y Interaction Enhances Proliferation of Granule Precursor Cells and Expression of Neuroprotective Factors in the Rat Hippocampus with Consequent Augmented Spatial Memory. Biomedicines 2022; 10:biomedicines10061297. [PMID: 35740319 PMCID: PMC9219743 DOI: 10.3390/biomedicines10061297] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 02/04/2023] Open
Abstract
Dysregulation of hippocampal neurogenesis is linked to several neurodegenereative diseases, where boosting hippocampal neurogenesis in these patients emerges as a potential therapeutic approach. Accumulating evidence for a neuropeptide Y (NPY) and galanin (GAL) interaction was shown in various limbic system regions at molecular-, cellular-, and behavioral-specific levels. The purpose of the current work was to evaluate the role of the NPY and GAL interaction in the neurogenic actions on the dorsal hippocampus. We studied the Y1R agonist and GAL effects on: hippocampal cell proliferation through the proliferating cell nuclear antigen (PCNA), the expression of neuroprotective and anti-apoptotic factors, and the survival of neurons and neurite outgrowth on hippocampal neuronal cells. The functional outcome was evaluated in the object-in-place task. We demonstrated that the Y1R agonist and GAL promote cell proliferation and the induction of neuroprotective factors. These effects were mediated by the interaction of NPYY1 (Y1R) and GAL2 (GALR2) receptors, which mediate the increased survival and neurites’ outgrowth observed on neuronal hippocampal cells. These cellular effects are linked to the improved spatial-memory effects after the Y1R agonist and GAL co-injection at 24 h in the object-in-place task. Our results suggest the development of heterobivalent agonist pharmacophores, targeting Y1R–GALR2 heterocomplexes, therefore acting on the neuronal precursor cells of the DG in the dorsal hippocampus for the novel therapy of neurodegenerative cognitive-affecting diseases.
Collapse
|
45
|
Simonova NA, Volgushev MA, Malyshev AY. Enhanced Non-Associative Long-Term Potentiation in Immature Granule Cells in the Dentate Gyrus of Adult Rats. Front Synaptic Neurosci 2022; 14:889947. [PMID: 35711669 PMCID: PMC9192440 DOI: 10.3389/fnsyn.2022.889947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 04/15/2022] [Indexed: 11/20/2022] Open
Abstract
The dentate gyrus is one of the few sites of neurogenesis in the adult brain. Integration of new-generated granule cells into the hippocampal circuitry provides a substrate for structural plasticity, fundamental for normal function of adult hippocampus. However, mechanisms of synaptic plasticity that mediate integration of new-generated granule cells into the existing circuitry remain poorly understood. Especially mechanisms of plasticity at GABA-ergic synapses remain elusive. Here, we show that postsynaptic spiking without presynaptic activation can induce heterosynaptic, non-associative plasticity at GABA-ergic inputs to both immature and mature granule cells. In both immature and mature neurons, plastic changes were bidirectional and individual inputs could express long-term potentiation (LTP) or long-term depression (LTD), or do not change. However, properties of non-associative plasticity dramatically change with maturation of newly generated granule cells: while in immature cells there was a clear predominance of non-associative LTP and net potentiation across the inputs, in mature neurons, potentiation and depression were balanced with no net change on average. We conclude that GABA-ergic inputs to granule cells are plastic, and that the rules for induction of non-associative plasticity change with maturation. We propose that potentiation-biased non-associative plasticity of GABA-ergic transmission might help to counter-balance an increase of excitatory drive that is facilitated by enhanced LTP at glutamatergic synapses in maturating granule cells. Such mechanism might help to build a strong GABA-ergic input to surviving active new cells, necessary for normal function of mature granule cells, which operate under a tight inhibitory control and generate sparse spiking activity.
Collapse
Affiliation(s)
- Natalia A. Simonova
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
| | - Maxim A. Volgushev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
- Department of Psychological Sciences, University of Connecticut, Storrs, CT, United States
- *Correspondence: Maxim A. Volgushev
| | - Alexey Y. Malyshev
- Institute of Higher Nervous Activity and Neurophysiology of Russian Academy of Sciences, Moscow, Russia
| |
Collapse
|
46
|
Bond AM, Ming GL, Song H. What Is the Relationship Between Hippocampal Neurogenesis Across Different Stages of the Lifespan? Front Neurosci 2022; 16:891713. [PMID: 35685774 PMCID: PMC9173723 DOI: 10.3389/fnins.2022.891713] [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: 03/08/2022] [Accepted: 04/25/2022] [Indexed: 12/02/2022] Open
Abstract
Hippocampal neurogenesis has typically been studied during embryonic development or in adulthood, promoting the perception of two distinct phenomena. We propose a perspective that hippocampal neurogenesis in the mammalian brain is one continuous, lifelong developmental process. We summarize the common features of hippocampal neurogenesis that are maintained across the lifespan, as well as dynamic age-dependent properties. We highlight that while the progression of hippocampal neurogenesis across the lifespan is conserved between mammalian species, the timing of this progression is species-dependent. Finally, we discuss some current challenges in the hippocampus neurogenesis field, and future research directions to address them, such as time course analysis across the lifespan, mechanisms regulating neurogenesis progression, and interspecies comparisons. We hope that this new perspective of hippocampal neurogenesis will prompt fresh insight into previous research and inspire new directions to advance the field to identify biologically significant ways to harness the endogenous capacity for neurogenesis in the hippocampus.
Collapse
Affiliation(s)
- Allison M. Bond
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Guo-li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Hongjun Song
- Department of Neuroscience and Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,The Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: Hongjun Song,
| |
Collapse
|
47
|
Shridhar S, Mishra P, Narayanan R. Dominant role of adult neurogenesis-induced structural heterogeneities in driving plasticity heterogeneity in dentate gyrus granule cells. Hippocampus 2022; 32:488-516. [PMID: 35561083 PMCID: PMC9322436 DOI: 10.1002/hipo.23422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 04/21/2022] [Accepted: 04/28/2022] [Indexed: 02/02/2023]
Abstract
Neurons and synapses manifest pronounced variability in the amount of plasticity induced by identical activity patterns. The mechanisms underlying such plasticity heterogeneity, which have been implicated in context‐specific resource allocation during encoding, have remained unexplored. Here, we employed a systematic physiologically constrained parametric search to identify the cellular mechanisms behind plasticity heterogeneity in dentate gyrus granule cells. We used heterogeneous model populations to ensure that our conclusions were not biased by parametric choices in a single hand‐tuned model. We found that each of intrinsic, synaptic, and structural heterogeneities independently yielded heterogeneities in synaptic plasticity profiles obtained with two different induction protocols. However, among the disparate forms of neural‐circuit heterogeneities, our analyses demonstrated the dominance of neurogenesis‐induced structural heterogeneities in driving plasticity heterogeneity in granule cells. We found that strong relationships between neuronal intrinsic excitability and plasticity emerged only when adult neurogenesis‐induced heterogeneities in neural structure were accounted for. Importantly, our analyses showed that it was not imperative that the manifestation of neural‐circuit heterogeneities must translate to heterogeneities in plasticity profiles. Specifically, despite the expression of heterogeneities in structural, synaptic, and intrinsic neuronal properties, similar plasticity profiles were attainable across all models through synergistic interactions among these heterogeneities. We assessed the parametric combinations required for the manifestation of such degeneracy in the expression of plasticity profiles. We found that immature cells showed physiological plasticity profiles despite receiving afferent inputs with weak synaptic strengths. Thus, the high intrinsic excitability of immature granule cells was sufficient to counterbalance their low excitatory drive in the expression of plasticity profile degeneracy. Together, our analyses demonstrate that disparate forms of neural‐circuit heterogeneities could mechanistically drive plasticity heterogeneity, but also caution against treating neural‐circuit heterogeneities as proxies for plasticity heterogeneity. Our study emphasizes the need for quantitatively characterizing the relationship between neural‐circuit and plasticity heterogeneities across brain regions.
Collapse
Affiliation(s)
- Sameera Shridhar
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Poonam Mishra
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| |
Collapse
|
48
|
Li YD, Luo YJ, Chen ZK, Quintanilla L, Cherasse Y, Zhang L, Lazarus M, Huang ZL, Song J. Hypothalamic modulation of adult hippocampal neurogenesis in mice confers activity-dependent regulation of memory and anxiety-like behavior. Nat Neurosci 2022; 25:630-645. [PMID: 35524139 PMCID: PMC9287980 DOI: 10.1038/s41593-022-01065-x] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 03/29/2022] [Indexed: 12/30/2022]
Abstract
Adult hippocampal neurogenesis plays a critical role in memory and emotion processing, and this process is dynamically regulated by neural circuit activity. However, it remains unknown whether manipulation of neural circuit activity can achieve sufficient neurogenic effects to modulate behavior. Here we report that chronic patterned optogenetic stimulation of supramammillary nucleus (SuM) neurons in the mouse hypothalamus robustly promotes neurogenesis at multiple stages, leading to increased production of neural stem cells and behaviorally relevant adult-born neurons (ABNs) with enhanced maturity. Functionally, selective manipulation of the activity of these SuM-promoted ABNs modulates memory retrieval and anxiety-like behaviors. Furthermore, we show that SuM neurons are highly responsive to environmental novelty (EN) and are required for EN-induced enhancement of neurogenesis. Moreover, SuM is required for ABN activity-dependent behavioral modulation under a novel environment. Our study identifies a key hypothalamic circuit that couples novelty signals to the production and maturation of ABNs, and highlights the activity-dependent contribution of circuit-modified ABNs in behavioral regulation.
Collapse
Affiliation(s)
- Ya-Dong Li
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yan-Jia Luo
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Ze-Ka Chen
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Luis Quintanilla
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Neuroscience Curriculum, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Yoan Cherasse
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Libo Zhang
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Michael Lazarus
- International Institute for Integrative Sleep Medicine (WPI-IIIS) and Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Zhi-Li Huang
- Department of Pharmacology, School of Basic Medical Sciences; State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Juan Song
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
- Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| |
Collapse
|
49
|
Arredondo SB, Valenzuela-Bezanilla D, Santibanez SH, Varela-Nallar L. Wnt signaling in the adult hippocampal neurogenic niche. Stem Cells 2022; 40:630-640. [PMID: 35446432 DOI: 10.1093/stmcls/sxac027] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 03/29/2022] [Indexed: 11/14/2022]
Abstract
The subgranular zone (SGZ) of the hippocampal dentate gyrus (DG) is a neurogenic niche of the adult brain that contains neural stem cells (NSCs) able to generate excitatory glutamatergic granule neurons, which integrate into the DG circuit and contribute to hippocampal plasticity, learning, and memory. Thus, endogenous NSCs could be harnessed for therapeutic purposes. In this context, it is critical to characterize the molecular mechanisms controlling the generation and functional integration of adult-born neurons. Adult hippocampal neurogenesis is tightly controlled by both cell-autonomous mechanisms and the interaction with the complex niche microenvironment, which harbors the NSCs and provides the signals to support their maintenance, activation, and differentiation. Among niche-derived factors, Wnt ligands play diverse roles. Wnts are secreted glycoproteins that bind to Frizzled receptors and co-receptors to trigger the Wnt signaling pathway. Here, we summarize the current knowledge about the roles of Wnts in the regulation of adult hippocampal neurogenesis. We discuss the possible contribution of the different niche cells to the regulation of local Wnt signaling activity, and how Wnts derived from different cell types could induce differential effects. Finally, we discuss how the effects of Wnt signaling on hippocampal network activity might contribute to neurogenesis regulation. Although the evidence supports relevant roles for Wnt signaling in adult hippocampal neurogenesis, defining the cellular source and the mechanisms controlling secretion and diffusion of Wnts will be crucial to further understand Wnt signaling regulation of adult NSCs, and eventually, to propose this pathway as a therapeutic target to promote neurogenesis.
Collapse
Affiliation(s)
- Sebastian B Arredondo
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370071, Santiago, Chile
| | - Daniela Valenzuela-Bezanilla
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370071, Santiago, Chile
| | - Sebastian H Santibanez
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370071, Santiago, Chile
| | - Lorena Varela-Nallar
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andres Bello, Echaurren 183, 8370071, Santiago, Chile
| |
Collapse
|
50
|
Kempermann G. What Is Adult Hippocampal Neurogenesis Good for? Front Neurosci 2022; 16:852680. [PMID: 35495058 PMCID: PMC9051245 DOI: 10.3389/fnins.2022.852680] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 03/17/2022] [Indexed: 12/29/2022] Open
Abstract
Adult hippocampal neurogenesis is a unique and exceptional process in the mammalian brain that in a lifelong and activity-dependent way generates new excitatory principal neurons. A comprehensive view on their function in greater contexts has now emerged, revealing to which extent the hippocampus (and hence brain and mind) depend on these neurons. Due to a postmitotic period of heightened synaptic plasticity they bias incoming excitation to the dentate gyrus to non-overlapping subnetworks, resulting in pattern separation and the avoidance of catastrophic interference. Temporally, this promotes the flexible integration of novel information into familiar contexts and contributes to episodic memory, which in humans would be critical for autobiographic memory. Together these local effects represent a unique strategy to solve the plasticity-stability dilemma that all learning neuronal networks are facing. Neurogenesis-dependent plasticity also improves memory consolidation. This relates to the surprising involvement of adult neurogenesis in forgetting, which is also hypothesized to be critically relevant for negative plasticity, for example in post-traumatic stress disorder. In addition, adult-born neurons also directly mediate stress-resilience and take part in affective behaviors. Finally, the activity- and experience-dependent plasticity that is contributed by adult neurogenesis is associated with an individualization of the hippocampal circuitry. While a solid and largely consensual understanding of how new neurons contribute to hippocampal function has been reached, an overarching unifying theory that embeds neurogenesis-dependent functionality and effects on connectomics is still missing. More sophisticated multi-electrode electrophysiology, advanced ethologically relevant behavioral tests, and next-generation computational modeling will let us take the next steps.
Collapse
Affiliation(s)
- Gerd Kempermann
- German Center for Neurodegenerative Diseases (DZNE), Dresden, Germany
- Center for Regenerative Therapies Dresden (CRTD), Technische Universität Dresden, Dresden, Germany
- *Correspondence: Gerd Kempermann, ;
| |
Collapse
|