1
|
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
|
2
|
Firoozi A, Alizadeh A, Zarifkar A, Esmaeilpour T, Namavar MR, Alavi O, Dehghani F. Comparison of the efficacy of human umbilical cord mesenchymal stem cells conditioned medium and platelet-rich plasma on the hippocampus of STZ-induced rat model of Alzheimer's disease: A behavioral and stereological study. IBRO Neurosci Rep 2023; 15:209-217. [PMID: 37780033 PMCID: PMC10539893 DOI: 10.1016/j.ibneur.2023.09.006] [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: 06/25/2023] [Revised: 08/13/2023] [Accepted: 09/12/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Alzheimer's disease (AD) is accompanied by progressive cognitive disorders and memory loss. This study aims to determine the combined effects of conditioned medium of human umbilical cord mesenchymal stem cells (CM) and platelet-rich plasma (PRP) on AD model rats. Methods Forty-eight male Sprague Dawley rats were classified into 6 groups: Control, Sham, AD, and three treatment groups. AD was induced by streptozotocin(STZ; 3 mg/kg, intracerebroventricular (ICV)) and the treatment groups received injections of CM [(200 µl, intraperitoneally (i.p.), and/or PRP (100 µl, intravenously(i.v)] for 8 days. Behavioral tests (Morris water maze and novel objective recognition) were used to assess learning ability and memory. At the end of the behavioral tests, the rats were sacrificed and their brain was entirely removed, sectioned, and stained with cresyl violet. The hippocampus volume and number of neurons were evaluated by stereological techniques. Results In the AD group, the discrimination ratio, time spent in the target zone, volume of Cornu Ammonis1 (CA1) and Dentate Gyrus (DG), and the number of pyramidal and granular cells decreased significantly compared to the Sham group. The mentioned parameters increased in the CM and CM+PRP groups compared to the AD group (p < 0.01). PRP did not have any noticeable effect on the examined parameters. Conclusions CM may be beneficial in the treatment of AD as it led to better improvement in STZ-induced learning and memory impairments as well as the structure of the hippocampus.
Collapse
Affiliation(s)
- Amin Firoozi
- Department of Anatomy, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Histomorphometry & Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Aliakbar Alizadeh
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Asadollah Zarifkar
- Neuroscience Research Center and Department of Physiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Tahereh Esmaeilpour
- Department of Anatomy, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Reza Namavar
- Department of Anatomy, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Histomorphometry & Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
- Clinical Neurology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Omid Alavi
- Department of Tissue Engineering and Applied Cell Sciences, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Farzaneh Dehghani
- Department of Anatomy, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
- Histomorphometry & Stereology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| |
Collapse
|
3
|
Berdugo‐Vega G, Dhingra S, Calegari F. Sharpening the blades of the dentate gyrus: how adult-born neurons differentially modulate diverse aspects of hippocampal learning and memory. EMBO J 2023; 42:e113524. [PMID: 37743770 PMCID: PMC11059975 DOI: 10.15252/embj.2023113524] [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: 01/16/2023] [Revised: 06/19/2023] [Accepted: 08/18/2023] [Indexed: 09/26/2023] Open
Abstract
For decades, the mammalian hippocampus has been the focus of cellular, anatomical, behavioral, and computational studies aimed at understanding the fundamental mechanisms underlying cognition. Long recognized as the brain's seat for learning and memory, a wealth of knowledge has been accumulated on how the hippocampus processes sensory input, builds complex associations between objects, events, and space, and stores this information in the form of memories to be retrieved later in life. However, despite major efforts, our understanding of hippocampal cognitive function remains fragmentary, and models trying to explain it are continually revisited. Here, we review the literature across all above-mentioned domains and offer a new perspective by bringing attention to the most distinctive, and generally neglected, feature of the mammalian hippocampal formation, namely, the structural separability of the two blades of the dentate gyrus into "supra-pyramidal" and "infra-pyramidal". Next, we discuss recent reports supporting differential effects of adult neurogenesis in the regulation of mature granule cell activity in these two blades. We propose a model for how differences in connectivity and adult neurogenesis in the two blades can potentially provide a substrate for subtly different cognitive functions.
Collapse
Affiliation(s)
- Gabriel Berdugo‐Vega
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
- Present address:
Laboratory of Neuroepigenetics, Brain Mind Institute, School of Life Sciences, École Polytechnique Fédérale Lausanne (EPFL)LausanneSwitzerland
| | - Shonali Dhingra
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| | - Federico Calegari
- CRTD‐Center for Regenerative Therapies DresdenTechnische Universität DresdenDresdenGermany
| |
Collapse
|
4
|
Nazari-Serenjeh F, Azizbeigi R, Rashvand M, Mesgar S, Amirteymori H, Haghparast A. Distinct roles for orexin-1 and orexin-2 receptors in the dentate gyrus of the hippocampus in the methamphetamine-seeking behavior in the rats. Life Sci 2023; 312:121262. [PMID: 36470538 DOI: 10.1016/j.lfs.2022.121262] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 12/11/2022]
Abstract
Because of the relapsing properties of psychostimulants such as methamphetamine (Meth), there is no established pharmacotherapy for Meth addiction. The orexinergic system is a promising target for treating psychostimulant use disorders and relapse. However, to the best of our knowledge, no investigation regarding the role of orexin receptors in the dentate gyrus (DG) region of the hippocampus has been conducted in the extinction and reinstatement of Meth-seeking behavior. Two stainless-steel guide cannulae were bilaterally implanted into the DG of the rats' brains. The unbiased conditioned place preference (CPP) procedure was conducted to induce Meth conditioning. Following the five days Meth injections (1 mg/kg; sc), animals received intra-DG microinjection of SB334867 or TCS OX2 29, as orexin 1 (OX1) or orexin 2 (OX2) receptor antagonists, respectively (without Meth administration) during extinction phase to elucidate the role of orexin receptors in the latency of the extinction period in the Meth-conditioned rats. To evaluate the role of orexin receptors in the DG region in the reinstatement of Meth-seeking behavior, the extinguished rats received SB334867 or TCS OX2 29 before injecting a priming dose of Meth (0.25 mg/kg; sc). The results indicated two distinct roles for the OX1 and OX2 receptors in the DG region. TCS OX2 29 attenuated the extinction latency, and SB334867 considerably reduced the reinstatement of Meth-seeking behavior in this region. Therefore, the DG region's orexinergic system might be a potential therapeutic target for psychostimulant use disorders.
Collapse
Affiliation(s)
| | - Ronak Azizbeigi
- Department of Basic Sciences, Sanandaj Branch, Islamic Azad University, Sanandaj, Iran
| | - Mina Rashvand
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Somaye Mesgar
- Neurobiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Haleh Amirteymori
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abbas Haghparast
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; School of Cognitive Sciences, Institute for Research in Fundamental Sciences, Tehran, Iran.
| |
Collapse
|
5
|
Pathological Nuclear Hallmarks in Dentate Granule Cells of Alzheimer’s Patients: A Biphasic Regulation of Neurogenesis. Int J Mol Sci 2022; 23:ijms232112873. [PMID: 36361662 PMCID: PMC9654738 DOI: 10.3390/ijms232112873] [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: 09/24/2022] [Revised: 10/14/2022] [Accepted: 10/18/2022] [Indexed: 11/29/2022] Open
Abstract
The dentate gyrus (DG) of the human hippocampus is a complex and dynamic structure harboring mature and immature granular neurons in diverse proliferative states. While most mammals show persistent neurogenesis through adulthood, human neurogenesis is still under debate. We found nuclear alterations in granular cells in autopsied human brains, detected by immunohistochemistry. These alterations differ from those reported in pyramidal neurons of the hippocampal circuit. Aging and early AD chromatin were clearly differentiated by the increased epigenetic markers H3K9me3 (heterochromatin suppressive mark) and H3K4me3 (transcriptional euchromatin mark). At early AD stages, lamin B2 was redistributed to the nucleoplasm, indicating cell-cycle reactivation, probably induced by hippocampal nuclear pathology. At intermediate and late AD stages, higher lamin B2 immunopositivity in the perinucleus suggests fewer immature neurons, less neurogenesis, and fewer adaptation resources to environmental factors. In addition, senile samples showed increased nuclear Tau interacting with aged chromatin, likely favoring DNA repair and maintaining genomic stability. However, at late AD stages, the progressive disappearance of phosphorylated Tau forms in the nucleus, increased chromatin disorganization, and increased nuclear autophagy support a model of biphasic neurogenesis in AD. Therefore, designing therapies to alleviate the neuronal nuclear pathology might be the only pathway to a true rejuvenation of brain circuits.
Collapse
|
6
|
Ogando MB, Pedroncini O, Federman N, Romano SA, Brum LA, Lanuza GM, Refojo D, Marin-Burgin A. Cholinergic modulation of dentate gyrus processing through dynamic reconfiguration of inhibitory circuits. Cell Rep 2021; 36:109572. [PMID: 34433032 DOI: 10.1016/j.celrep.2021.109572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 06/28/2021] [Accepted: 07/30/2021] [Indexed: 10/20/2022] Open
Abstract
The dentate gyrus (DG) of the hippocampus plays a key role in memory formation, and it is known to be modulated by septal projections. By performing electrophysiology and optogenetics, we evaluated the role of cholinergic modulation in the processing of afferent inputs in the DG. We show that mature granule cells (GCs), but not adult-born immature neurons, have increased responses to afferent perforant path stimuli upon cholinergic modulation. This is due to a highly precise reconfiguration of inhibitory circuits, differentially affecting Parvalbumin and Somatostatin interneurons, resulting in a nicotinic-dependent perisomatic disinhibition of GCs. This circuit reorganization provides a mechanism by which mature GCs could escape the strong inhibition they receive, creating a window of opportunity for plasticity. Indeed, coincident activation of perforant path inputs with optogenetic release of acetylcholine produces a long-term potentiated response in GCs, essential for memory formation.
Collapse
Affiliation(s)
- Mora B Ogando
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina.
| | - Olivia Pedroncini
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
| | - Noel Federman
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
| | - Sebastián A Romano
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
| | - Luciano A Brum
- Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Guillermo M Lanuza
- Fundación Instituto Leloir-Instituto de Investigaciones Bioquímicas de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Av. Patricias Argentinas 435, Buenos Aires C1405BWE, Argentina
| | - Damian Refojo
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina
| | - Antonia Marin-Burgin
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society Godoy Cruz 2390, C1425FQD Buenos Aires, Argentina.
| |
Collapse
|
7
|
Byman E, Martinsson I, Haukedal H, Gouras G, Freude KK, Wennström M. Neuronal α-amylase is important for neuronal activity and glycogenolysis and reduces in presence of amyloid beta pathology. Aging Cell 2021; 20:e13433. [PMID: 34261192 PMCID: PMC8373367 DOI: 10.1111/acel.13433] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/23/2021] [Accepted: 07/03/2021] [Indexed: 12/28/2022] Open
Abstract
Recent studies indicate a crucial role for neuronal glycogen storage and degradation in memory formation. We have previously identified alpha-amylase (α-amylase), a glycogen degradation enzyme, located within synaptic-like structures in CA1 pyramidal neurons and shown that individuals with a high copy number variation of α-amylase perform better on the episodic memory test. We reported that neuronal α-amylase was absent in patients with Alzheimer's disease (AD) and that this loss corresponded to increased AD pathology. In the current study, we verified these findings in a larger patient cohort and determined a similar reduction in α-amylase immunoreactivity in the molecular layer of hippocampus in AD patients. Next, we demonstrated reduced α-amylase concentrations in oligomer amyloid beta 42 (Aβ42 ) stimulated SH-SY5Y cells and neurons derived from human-induced pluripotent stem cells (hiPSC) with PSEN1 mutation. Reduction of α-amylase production and activity, induced by siRNA and α-amylase inhibitor Tendamistat, respectively, was further shown to enhance glycogen load in SH-SY5Y cells. Both oligomer Aβ42 stimulated SH-SY5Y cells and hiPSC neurons with PSEN1 mutation showed, however, reduced load of glycogen. Finally, we demonstrate the presence of α-amylase within synapses of isolated primary neurons and show that inhibition of α-amylase activity with Tendamistat alters neuronal activity measured by calcium imaging. In view of these findings, we hypothesize that α-amylase has a glycogen degrading function within synapses, potentially important in memory formation. Hence, a loss of α-amylase, which can be induced by Aβ pathology, may in part underlie the disrupted memory formation seen in AD patients.
Collapse
Affiliation(s)
- Elin Byman
- Clinical Memory Research UnitDepartment of Clinical Sciences MalmöLund UniversityMalmöSweden
| | - Isak Martinsson
- Experimental Dementia Research UnitDepartment of Experimental Medical ScienceBMC B11Lund UniversityLundSweden
| | - Henriette Haukedal
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksbergDenmark
| | | | - Gunnar Gouras
- Experimental Dementia Research UnitDepartment of Experimental Medical ScienceBMC B11Lund UniversityLundSweden
| | - Kristine K. Freude
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksbergDenmark
| | - Malin Wennström
- Clinical Memory Research UnitDepartment of Clinical Sciences MalmöLund UniversityMalmöSweden
| |
Collapse
|
8
|
Cheng J, Scala F, Blanco FA, Niu S, Firozi K, Keehan L, Mulherkar S, Froudarakis E, Li L, Duman JG, Jiang X, Tolias KF. The Rac-GEF Tiam1 Promotes Dendrite and Synapse Stabilization of Dentate Granule Cells and Restricts Hippocampal-Dependent Memory Functions. J Neurosci 2021; 41:1191-1206. [PMID: 33328293 PMCID: PMC7888217 DOI: 10.1523/jneurosci.3271-17.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 11/25/2020] [Accepted: 12/01/2020] [Indexed: 12/14/2022] Open
Abstract
The dentate gyrus (DG) controls information flow into the hippocampus and is critical for learning, memory, pattern separation, and spatial coding, while DG dysfunction is associated with neuropsychiatric disorders. Despite its importance, the molecular mechanisms regulating DG neural circuit assembly and function remain unclear. Here, we identify the Rac-GEF Tiam1 as an important regulator of DG development and associated memory processes. In the hippocampus, Tiam1 is predominantly expressed in the DG throughout life. Global deletion of Tiam1 in male mice results in DG granule cells with simplified dendritic arbors, reduced dendritic spine density, and diminished excitatory synaptic transmission. Notably, DG granule cell dendrites and synapses develop normally in Tiam1 KO mice, resembling WT mice at postnatal day 21 (P21), but fail to stabilize, leading to dendrite and synapse loss by P42. These results indicate that Tiam1 promotes DG granule cell dendrite and synapse stabilization late in development. Tiam1 loss also increases the survival, but not the production, of adult-born DG granule cells, possibly because of greater circuit integration as a result of decreased competition with mature granule cells for synaptic inputs. Strikingly, both male and female mice lacking Tiam1 exhibit enhanced contextual fear memory and context discrimination. Together, these results suggest that Tiam1 is a key regulator of DG granule cell stabilization and function within hippocampal circuits. Moreover, based on the enhanced memory phenotype of Tiam1 KO mice, Tiam1 may be a potential target for the treatment of disorders involving memory impairments.SIGNIFICANCE STATEMENT The dentate gyrus (DG) is important for learning, memory, pattern separation, and spatial navigation, and its dysfunction is associated with neuropsychiatric disorders. However, the molecular mechanisms controlling DG formation and function remain elusive. By characterizing mice lacking the Rac-GEF Tiam1, we demonstrate that Tiam1 promotes the stabilization of DG granule cell dendritic arbors, spines, and synapses, whereas it restricts the survival of adult-born DG granule cells, which compete with mature granule cells for synaptic integration. Notably, mice lacking Tiam1 also exhibit enhanced contextual fear memory and context discrimination. These findings establish Tiam1 as an essential regulator of DG granule cell development, and identify it as a possible therapeutic target for memory enhancement.
Collapse
Affiliation(s)
- Jinxuan Cheng
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Federico Scala
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Francisco A Blanco
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Integrative Molecular and Biomedical Science Graduate Program, Baylor College of Medicine, Houston, Texas 77030
| | - Sanyong Niu
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Karen Firozi
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Laura Keehan
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Shalaka Mulherkar
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | | | - Lingyong Li
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Joseph G Duman
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| | - Xiaolong Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, Texas 77030
| | - Kimberley F Tolias
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
| |
Collapse
|
9
|
von Wittgenstein J, Zheng F, Wittmann MT, Balta EA, Ferrazzi F, Schäffner I, Häberle BM, Valero-Aracama MJ, Koehl M, Miranda CJ, Kaspar BK, Ekici AB, Reis A, Abrous DN, Alzheimer C, Lie DC. Sox11 is an Activity-Regulated Gene with Dentate-Gyrus-Specific Expression Upon General Neural Activation. Cereb Cortex 2020; 30:3731-3743. [PMID: 32080705 DOI: 10.1093/cercor/bhz338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 06/25/2019] [Accepted: 07/04/2019] [Indexed: 01/21/2023] Open
Abstract
Neuronal activity initiates transcriptional programs that shape long-term changes in plasticity. Although neuron subtypes differ in their plasticity response, most activity-dependent transcription factors (TFs) are broadly expressed across neuron subtypes and brain regions. Thus, how region- and neuronal subtype-specific plasticity are established on the transcriptional level remains poorly understood. We report that in young adult (i.e., 6-8 weeks old) mice, the developmental TF SOX11 is induced in neurons within 6 h either by electroconvulsive stimulation or by exploration of a novel environment. Strikingly, SOX11 induction was restricted to the dentate gyrus (DG) of the hippocampus. In the novel environment paradigm, SOX11 was observed in a subset of c-FOS expressing neurons (ca. 15%); whereas around 75% of SOX11+ DG granule neurons were c-FOS+, indicating that SOX11 was induced in an activity-dependent fashion in a subset of neurons. Environmental enrichment or virus-mediated overexpression of SOX11 enhanced the excitability of DG granule cells and downregulated the expression of different potassium channel subunits, whereas conditional Sox11/4 knock-out mice presented the opposite phenotype. We propose that Sox11 is regulated in an activity-dependent fashion, which is specific to the DG, and speculate that activity-dependent Sox11 expression may participate in the modulation of DG neuron plasticity.
Collapse
Affiliation(s)
- Julia von Wittgenstein
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.,Department of Biology, Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Fang Zheng
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Marie-Theres Wittmann
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany.,Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Elli-Anna Balta
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Fulvia Ferrazzi
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Iris Schäffner
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Benjamin M Häberle
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Maria J Valero-Aracama
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Muriel Koehl
- Neurocentre Magendie U1215, INSERM and Université de Bordeaux, Bordeaux 33000, France
| | - Carlos J Miranda
- The Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Brian K Kaspar
- The Research Institute, Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Djoher Nora Abrous
- Neurocentre Magendie U1215, INSERM and Université de Bordeaux, Bordeaux 33000, France
| | - Christian Alzheimer
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - D Chichung Lie
- Institute of Biochemistry, Emil Fischer Center, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| |
Collapse
|
10
|
Kv4.1, a Key Ion Channel For Low Frequency Firing of Dentate Granule Cells, Is Crucial for Pattern Separation. J Neurosci 2020; 40:2200-2214. [PMID: 32047055 DOI: 10.1523/jneurosci.1541-19.2020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 12/30/2019] [Accepted: 01/23/2020] [Indexed: 11/21/2022] Open
Abstract
The dentate gyrus (DG) in the hippocampus may play key roles in remembering distinct episodes through pattern separation, which may be subserved by the sparse firing properties of granule cells (GCs) in the DG. Low intrinsic excitability is characteristic of mature GCs, but ion channel mechanisms are not fully understood. Here, we investigated ionic channel mechanisms for firing frequency regulation in hippocampal GCs using male and female mice, and identified Kv4.1 as a key player. Immunofluorescence analysis showed that Kv4.1 was preferentially expressed in the DG, and its expression level determined by Western blot analysis was higher at 8-week than 3-week-old mice, suggesting a developmental regulation of Kv4.1 expression. With respect to firing frequency, GCs are categorized into two distinctive groups: low-frequency (LF) and high-frequency (HF) firing GCs. Input resistance (R in) of most LF-GCs is lower than 200 MΩ, suggesting that LF-GCs are fully mature GCs. Kv4.1 channel inhibition by intracellular perfusion of Kv4.1 antibody increased firing rates and gain of the input-output relationship selectively in LF-GCs with no significant effect on resting membrane potential and R in, but had no effect in HF-GCs. Importantly, mature GCs from mice depleted of Kv4.1 transcripts in the DG showed increased firing frequency, and these mice showed an impairment in contextual discrimination task. Our findings suggest that Kv4.1 expression occurring at late stage of GC maturation is essential for low excitability of DG networks and thereby contributes to pattern separation.SIGNIFICANCE STATEMENT The sparse activity of dentate granule cells (GCs), which is essential for pattern separation, is supported by high inhibitory inputs and low intrinsic excitability of GCs. Low excitability of GCs is thought to be attributable to a high K+ conductance at resting membrane potentials, but this study identifies Kv4.1, a depolarization-activated K+ channel, as a key ion channel that regulates firing of GCs without affecting resting membrane potentials. Kv4.1 expression is developmentally regulated and Kv4.1 currents are detected only in mature GCs that show low-frequency firing, but not in less mature high-frequency firing GCs. Furthermore, mice depleted of Kv4.1 transcripts in the dentate gyrus show impaired pattern separation, suggesting that Kv4.1 is crucial for sparse coding and pattern separation.
Collapse
|
11
|
Christian KM, Ming GL, Song H. Adult neurogenesis and the dentate gyrus: Predicting function from form. Behav Brain Res 2019; 379:112346. [PMID: 31722241 DOI: 10.1016/j.bbr.2019.112346] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 11/05/2019] [Accepted: 11/05/2019] [Indexed: 12/11/2022]
Abstract
Hypotheses about the functional properties of the dentate gyrus and adult dentate neurogenesis have been shaped by early observations of the anatomy of this region, mostly in rodents. This has led to the development of a few core propositions that have guided research over the past several years, including the predicted role of this region in pattern separation and the local transformation of inputs from the entorhinal cortex. We now have the opportunity to review these predictions and update these anatomical observations based on recently developed techniques that reveal the complex structure, connectivity, and dynamic properties of distinct cell populations in the dentate gyrus at a higher resolution. Cumulative evidence suggests that the dentate gyrus and adult-born granule cells play a role in some forms of behavioral discriminations, but there are still many unanswered questions about how the dentate gyrus processes information to support the disambiguation of stimuli.
Collapse
Affiliation(s)
- Kimberly M Christian
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, 19104, USA; Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Guo-Li Ming
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, 19104, USA; Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Developmental and Cell Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Epigenetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hongjun Song
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, 19104, USA; Mahoney Institute for Neurosciences, University of Pennsylvania, Philadelphia, PA, 19104, USA; Department of Developmental and Cell Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA; Institute for Epigenetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
12
|
Dumenieu M, Senkov O, Mironov A, Bourinet E, Kreutz MR, Dityatev A, Heine M, Bikbaev A, Lopez-Rojas J. The Low-Threshold Calcium Channel Cav3.2 Mediates Burst Firing of Mature Dentate Granule Cells. Cereb Cortex 2019; 28:2594-2609. [PMID: 29790938 PMCID: PMC5998957 DOI: 10.1093/cercor/bhy084] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Indexed: 12/11/2022] Open
Abstract
Mature granule cells are poorly excitable neurons that were recently shown to fire action potentials, preferentially in bursts. It is believed that the particularly pronounced short-term facilitation of mossy fiber synapses makes granule cell bursting a very effective means of properly transferring information to CA3. However, the mechanism underlying the unique bursting behavior of mature granule cells is currently unknown. Here, we show that Cav3.2 T-type channels at the axon initial segment are responsible for burst firing of mature granule cells in rats and mice. Accordingly, Cav3.2 knockout mice fire tonic spikes and exhibit impaired bursting, synaptic plasticity and dentate-to-CA3 communication. The data show that Cav3.2 channels are strong modulators of bursting and can be considered a critical molecular switch that enables effective information transfer from mature granule cells to the CA3 pyramids.
Collapse
Affiliation(s)
- Mael Dumenieu
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Oleg Senkov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Andrey Mironov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Emmanuel Bourinet
- Calcium Channel Dynamics & Nociception Group, Institute of Functional Genomics, Montpellier, France
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany.,Leibniz Group "Dendritic Organelles and Synaptic Function," University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), Hamburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Martin Heine
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Arthur Bikbaev
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Jeffrey Lopez-Rojas
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| |
Collapse
|
13
|
Raghanti MA, Wicinski B, Meierovich R, Warda T, Dickstein DL, Reidenberg JS, Tang CY, George JC, Hans Thewissen JGM, Butti C, Hof PR. A Comparison of the Cortical Structure of the Bowhead Whale (Balaena mysticetus), a Basal Mysticete, with Other Cetaceans. Anat Rec (Hoboken) 2018; 302:745-760. [PMID: 30332717 DOI: 10.1002/ar.23991] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 09/12/2017] [Accepted: 10/16/2017] [Indexed: 12/13/2022]
Abstract
Few studies exist of the bowhead whale brain and virtually nothing is known about its cortical cytoarchitecture or how it compares to other cetaceans. Bowhead whales are one of the least encephalized cetaceans and occupy a basal phylogenetic position among mysticetes. Therefore, the bowhead whale is an important specimen for understanding the evolutionary specializations of cetacean brains. Here, we present an overview of the structure and cytoarchitecture of the bowhead whale cerebral cortex gleaned from Nissl-stained sections and magnetic resonance imaging (MRI) in comparison with other mysticetes and odontocetes. In general, the cytoarchitecture of cetacean cortex is consistent in displaying a thin cortex, a thick, prominent layer I, and absence of a granular layer IV. Cell density, composition, and width of layers III, V, and VI vary among cortical regions, and cetacean cortex is cell-sparse relative to that of terrestrial mammals. Notably, all regions of the bowhead cortex possess high numbers of von Economo neurons and fork neurons, with the highest numbers observed at the apex of gyri. The bowhead whale is also distinctive in having a significantly reduced hippocampus that occupies a space below the corpus callosum within the lateral ventricle. Consistent with other balaenids, bowhead whales possess what appears to be a blunted temporal lobe, which is in contrast to the expansive temporal lobes that characterize most odontocetes. The present report demonstrates that many morphological and cytoarchitectural characteristics are conserved among cetaceans, while other features, such as a reduced temporal lobe, may characterize balaenids among mysticetes. Anat Rec, 2018. © 2018 Wiley Periodicals, Inc. Anat Rec, 302:745-760, 2019. © 2018 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Mary Ann Raghanti
- Department of Anthropology and School of Biomedical Sciences, Kent State University, Kent, Ohio
| | - Bridget Wicinski
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Rachel Meierovich
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York.,Convent of the Sacred Heart School, New York, New York
| | - Tahia Warda
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Dara L Dickstein
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York.,Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Joy S Reidenberg
- Center for Anatomy and Functional Morphology, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Cheuk Y Tang
- Department of Radiology and Translational Medicine Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - John C George
- Department of Wildlife Management, North Slope Borough, Barrow, Alaska
| | - J G M Hans Thewissen
- Department of Anatomy and Neurobiology, Northeastern Ohio Medical University, Rootstown, Ohio
| | - Camilla Butti
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| |
Collapse
|
14
|
Hatami M, Conrad S, Naghsh P, Alvarez-Bolado G, Skutella T. Cell-Biological Requirements for the Generation of Dentate Gyrus Granule Neurons. Front Cell Neurosci 2018; 12:402. [PMID: 30483057 PMCID: PMC6240695 DOI: 10.3389/fncel.2018.00402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/18/2018] [Indexed: 12/22/2022] Open
Abstract
The dentate gyrus (DG) receives highly processed information from the associative cortices functionally integrated in the trisynaptic hippocampal circuit, which contributes to the formation of new episodic memories and the spontaneous exploration of novel environments. Remarkably, the DG is the only brain region currently known to have high rates of neurogenesis in adults (Andersen et al., 1966, 1971). The DG is involved in several neurodegenerative disorders, including clinical dementia, schizophrenia, depression, bipolar disorder and temporal lobe epilepsy. The principal neurons of the DG are the granule cells. DG granule cells generated in culture would be an ideal model to investigate their normal development and the causes of the pathologies in which they are involved and as well as possible therapies. Essential to establish such in vitro models is the precise definition of the most important cell-biological requirements for the differentiation of DG granule cells. This requires a deeper understanding of the precise molecular and functional attributes of the DG granule cells in vivo as well as the DG cells derived in vitro. In this review we outline the neuroanatomical, molecular and cell-biological components of the granule cell differentiation pathway, including some growth- and transcription factors essential for their development. We summarize the functional characteristics of DG granule neurons, including the electrophysiological features of immature and mature granule cells and the axonal pathfinding characteristics of DG neurons. Additionally, we discuss landmark studies on the generation of dorsal telencephalic precursors from pluripotent stem cells (PSCs) as well as DG neuron differentiation in culture. Finally, we provide an outlook and comment critical aspects.
Collapse
Affiliation(s)
- Maryam Hatami
- Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| | | | - Pooyan Naghsh
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, AB, Canada
| | | | - Thomas Skutella
- Institute for Anatomy and Cell Biology, Heidelberg University, Heidelberg, Germany
| |
Collapse
|
15
|
Abstract
The large-conductance calcium- and voltage-activated K+ (BK) channel has a requirement of high intracellular free Ca2+ concentrations for its activation in neurons under physiological conditions. The Ca2+ sources for BK channel activation are not well understood. In this study, we showed by coimmunopurification and colocalization analyses that BK channels form complexes with NMDA receptors (NMDARs) in both rodent brains and a heterologous expression system. The BK-NMDAR complexes are broadly present in different brain regions. The complex formation occurs between the obligatory BKα and GluN1 subunits likely via a direct physical interaction of the former's intracellular S0-S1 loop with the latter's cytosolic regions. By patch-clamp recording on mouse brain slices, we observed BK channel activation by NMDAR-mediated Ca2+ influx in dentate gyrus granule cells. BK channels modulate excitatory synaptic transmission via functional coupling with NMDARs at postsynaptic sites of medial perforant path-dentate gyrus granule cell synapses. A synthesized peptide of the BKα S0-S1 loop region, when loaded intracellularly via recording pipette, abolished the NMDAR-mediated BK channel activation and effect on synaptic transmission. These findings reveal the broad expression of the BK-NMDAR complexes in brain, the potential mechanism underlying the complex formation, and the NMDAR-mediated activation and function of postsynaptic BK channels in neurons.
Collapse
|
16
|
Hippocampal granule cell loss in human chronic alcohol abusers. Neurobiol Dis 2018; 120:63-75. [PMID: 30189262 DOI: 10.1016/j.nbd.2018.08.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/03/2018] [Accepted: 08/23/2018] [Indexed: 01/07/2023] Open
Abstract
Chronic alcohol abuse causes cognitive impairments associated with neurodegeneration and volume loss in the human hippocampus. Here, we hypothesize that alcohol reduces the number of granule cells in the human dentate gyrus and consequently contribute to the observed volume loss. Hippocampal samples were isolated from deceased donors with a history of chronic alcohol abuse and from controls with no alcohol overconsumption. From each case, a sample from the mid-portion of hippocampus was sectioned, immunostained for the neuronal nuclear marker NeuN, and counter stained with hematoxylin. Granule cell number and volume of granular cell layer in the dentate gyrus were estimated using stereology. We found a substantial reduction in granule cell number and also a significantly reduced volume of the granular cell layer of chronic alcohol abusers as compared to controls. In controls there was a slight age-related decline in the number of granule cells and volume of granular cell layer in line with previous studies. This was not observed among the alcoholics, possibly due to a larger impact of alcohol abuse than age on the degenerative changes in the dentate gyrus. Loss of neurons in the alcoholic group could either be explained by an increase of cell death or a reduced number of new cells added to the granular cell layer. However, there is no firm evidence for an increased neuronal death by chronic alcohol exposure, whereas a growing body of experimental data indicates that neurogenesis is impaired by alcohol. In a recent study, we reported that alcoholics show a reduced number of stem/progenitor cells and immature neurons in the dentate gyrus, hence that alcohol negatively affects hippocampal neurogenesis. The present results further suggest that such impairment of neurogenesis by chronic alcohol abuse also results in a net loss of granule cells in the dentate gyrus of hippocampus.
Collapse
|
17
|
AhR Deletion Promotes Aberrant Morphogenesis and Synaptic Activity of Adult-Generated Granule Neurons and Impairs Hippocampus-Dependent Memory. eNeuro 2018; 5:eN-NWR-0370-17. [PMID: 30225360 PMCID: PMC6140122 DOI: 10.1523/eneuro.0370-17.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 07/05/2018] [Accepted: 07/09/2018] [Indexed: 12/18/2022] Open
Abstract
Newborn granule cells are continuously produced in the subgranular zone of dentate gyrus throughout life. Once these cells mature, they integrate into pre-existing circuits modulating hippocampus-dependent memory. Subsequently, mechanisms controlling generation and maturation of newborn cells are essential for proper hippocampal function. Therefore, we have studied the role of aryl hydrocarbon receptor (AhR), a ligand-activated bHLH-PAS transcription factor, in hippocampus-dependent memory and granule neuronal morphology and function using genetic loss-of-function approaches based on constitutive and inducible-nestin AhR–/– mice. The results presented here show that the impaired hippocampus-dependent memory in AhR absence is not due to its effects on neurogenesis but to aberrant dendritic arborization and an increased spine density, albeit with a lower number of mature mushrooms spines in newborn granule cells, a finding that is associated with an immature electrophysiological phenotype. Together, our data strongly suggest that AhR plays a pivotal role in the regulation of hippocampal function, by controlling hippocampal granule neuron morphology and synaptic maturation.
Collapse
|
18
|
Ahn JH, Lee JS, Cho JH, Park JH, Lee TK, Song M, Kim H, Kang SH, Won MH, Lee CH. Age-dependent decrease of Nurr1 protein expression in the gerbil hippocampus. Biomed Rep 2018; 8:517-522. [PMID: 29904610 PMCID: PMC5996841 DOI: 10.3892/br.2018.1094] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 05/02/2018] [Indexed: 02/06/2023] Open
Abstract
Nuclear receptor related-1 protein (Nurr1) serves important roles in hippocampal-dependent cognitive process. In the present study, the protein expression of Nurr1 was compared in the hippocampi of young [postnatal month 3 (PM 3)], adult (PM 12) and aged (PM 24) gerbils using western blot analysis and immunohistochemistry. Results indicated that the protein level of Nurr1 was significantly and gradually decreased in the gerbil hippocampus with increasing age. In addition, strong Nurr1 immunoreactivity was primarily observed in pyramidal neurons and granule cells of the hippocampus in the young group, which was determined to be reduced in the adult group and to a greater extent in the aged group. Collectively the data demonstrated that Nurr1 immunoreactivity was gradually and markedly decreased during normal aging. These results indicate that gradual decrease of Nurr1 expression in the hippocampus may be associated with the normal aging process and a decline in hippocampus-dependent cognitive function.
Collapse
Affiliation(s)
- Ji Hyeon Ahn
- Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon, Gangwon 24252, Republic of Korea
| | - Joon Seok Lee
- Department of Emergency Medicine and Institute of Medical Sciences, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Jun Hwi Cho
- Department of Emergency Medicine and Institute of Medical Sciences, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Joon Ha Park
- Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon, Gangwon 24252, Republic of Korea
| | - Tae-Kyeong Lee
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Minah Song
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Hyunjung Kim
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Seok Hoon Kang
- Department of Medical Education, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Moo-Ho Won
- Department of Neurobiology, School of Medicine, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Choong Hyun Lee
- Department of Pharmacy, College of Pharmacy, Dankook University, Cheonan, Chungcheongnam 31116, Republic of Korea
| |
Collapse
|
19
|
Kassab R, Alexandre F. Pattern separation in the hippocampus: distinct circuits under different conditions. Brain Struct Funct 2018; 223:2785-2808. [PMID: 29637298 DOI: 10.1007/s00429-018-1659-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 03/26/2018] [Indexed: 10/17/2022]
Abstract
Pattern separation is a fundamental hippocampal process thought to be critical for distinguishing similar episodic memories, and has long been recognized as a natural function of the dentate gyrus (DG), supporting autoassociative learning in CA3. Understanding how neural circuits within the DG-CA3 network mediate this process has received much interest, yet the exact mechanisms behind remain elusive. Here, we argue for the case that sparse coding is necessary but not sufficient to ensure efficient separation and, alternatively, propose a possible interaction of distinct circuits which, nevertheless, act in synergy to produce a unitary function of pattern separation. The proposed circuits involve different functional granule-cell populations, a primary population mediates sparsification and provides recurrent excitation to the other populations which are related to additional pattern separation mechanisms with higher degrees of robustness against interference in CA3. A variety of top-down and bottom-up factors, such as motivation, emotion, and pattern similarity, control the selection of circuitry depending on circumstances. According to this framework, a computational model is implemented and tested against model variants in a series of numerical simulations and biological experiments. The results demonstrate that the model combines fast learning, robust pattern separation and high storage capacity. It also accounts for the controversy around the involvement of the DG during memory recall, explains other puzzling findings, and makes predictions that can inform future investigations.
Collapse
Affiliation(s)
- Randa Kassab
- INRIA, Bordeaux Sud-Ouest, Talence, France. .,Institut des Maladies Neurodégénératives, University of Bordeaux, CNRS UMR 5293-Case 28, Centre Broca Nouvelle-Aquitaine, 146 rue Léo Saignat, 33076, Bordeaux, France. .,LaBRI, UMR 5800, CNRS, Bordeaux INP, University of Bordeaux, Talence, France.
| | - Frédéric Alexandre
- INRIA, Bordeaux Sud-Ouest, Talence, France.,Institut des Maladies Neurodégénératives, University of Bordeaux, CNRS UMR 5293-Case 28, Centre Broca Nouvelle-Aquitaine, 146 rue Léo Saignat, 33076, Bordeaux, France.,LaBRI, UMR 5800, CNRS, Bordeaux INP, University of Bordeaux, Talence, France
| |
Collapse
|
20
|
Nandi S, Alviña K, Lituma PJ, Castillo PE, Hébert JM. Neurotrophin and FGF Signaling Adapter Proteins, FRS2 and FRS3, Regulate Dentate Granule Cell Maturation and Excitatory Synaptogenesis. Neuroscience 2017; 369:192-201. [PMID: 29155277 DOI: 10.1016/j.neuroscience.2017.11.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 11/07/2017] [Accepted: 11/11/2017] [Indexed: 12/15/2022]
Abstract
Dentate granule cells (DGCs) play important roles in cognitive processes. Knowledge about how growth factors such as FGFs and neurotrophins contribute to the maturation and synaptogenesis of DGCs is limited. Here, using brain-specific and germline mouse mutants we show that a module of neurotrophin and FGF signaling, the FGF Receptor Substrate (FRS) family of intracellular adapters, FRS2 and FRS3, are together required for postnatal brain development. In the hippocampus, FRS promotes dentate gyrus morphogenesis and DGC maturation during developmental neurogenesis, similar to previously published functions for both neurotrophins and FGFs. Consistent with a role in DGC maturation, two-photon imaging revealed that Frs2,3-double mutants have reduced numbers of dendritic branches and spines in DGCs. Functional analysis further showed that double-mutant mice exhibit fewer excitatory synaptic inputs onto DGCs. These observations reveal roles for FRS adapters in DGC maturation and synaptogenesis and suggest that FRS proteins may act as an important node for FGF and neurotrophin signaling in postnatal hippocampal development.
Collapse
Affiliation(s)
- Sayan Nandi
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Karina Alviña
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA
| | - Pablo J Lituma
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Pablo E Castillo
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Jean M Hébert
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| |
Collapse
|
21
|
Dietary Supplementation of Hericium erinaceus Increases Mossy Fiber-CA3 Hippocampal Neurotransmission and Recognition Memory in Wild-Type Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:3864340. [PMID: 28115973 PMCID: PMC5237458 DOI: 10.1155/2017/3864340] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 12/01/2016] [Accepted: 12/07/2016] [Indexed: 01/25/2023]
Abstract
Hericium erinaceus (Bull.) Pers. is a medicinal mushroom capable of inducing a large number of modulatory effects on human physiology ranging from the strengthening of the immune system to the improvement of cognitive functions. In mice, dietary supplementation with H. erinaceus prevents the impairment of spatial short-term and visual recognition memory in an Alzheimer model. Intriguingly other neurobiological effects have recently been reported like the effect on neurite outgrowth and differentiation in PC12 cells. Until now no investigations have been conducted to assess the impact of this dietary supplementation on brain function in healthy subjects. Therefore, we have faced the problem by considering the effect on cognitive skills and on hippocampal neurotransmission in wild-type mice. In wild-type mice the oral supplementation with H. erinaceus induces, in behaviour test, a significant improvement in the recognition memory and, in hippocampal slices, an increase in spontaneous and evoked excitatory synaptic current in mossy fiber-CA3 synapse. In conclusion, we have produced a series of findings in support of the concept that H. erinaceus induces a boost effect onto neuronal functions also in nonpathological conditions.
Collapse
|
22
|
Yun S, Reynolds RP, Masiulis I, Eisch AJ. Re-evaluating the link between neuropsychiatric disorders and dysregulated adult neurogenesis. Nat Med 2016; 22:1239-1247. [PMID: 27783068 PMCID: PMC5791154 DOI: 10.1038/nm.4218] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 09/30/2016] [Indexed: 12/11/2022]
Abstract
People diagnosed with neuropsychiatric disorders such as depression, anxiety, addiction or schizophrenia often have dysregulated memory, mood, pattern separation and/or reward processing. These symptoms are indicative of a disrupted function of the dentate gyrus (DG) subregion of the brain, and they improve with treatment and remission. The dysfunction of the DG is accompanied by structural maladaptations, including dysregulation of adult-generated neurons. An increasing number of studies using modern inducible approaches to manipulate new neurons show that the behavioral symptoms in animal models of neuropsychiatric disorders can be produced or exacerbated by the inhibition of DG neurogenesis. Thus, here we posit that the connection between neuropsychiatric disorders and dysregulated DG neurogenesis is beyond correlation or epiphenomenon, and that the regulation of adult-generated DG neurogenesis merits continued and focused attention in the ongoing effort to develop novel treatments for neuropsychiatric disorders.
Collapse
Affiliation(s)
- Sanghee Yun
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ryan P Reynolds
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Irene Masiulis
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Amelia J Eisch
- Department of Anesthesiology and Critical Care Medicine, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Department of Neuroscience and Mahoney Institute of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| |
Collapse
|