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Conrad LJ, Grandi FC, Carlton AJ, Jeng JY, de Tomasi L, Zarecki P, Marcotti W, Johnson SL, Mustapha M. The upregulation of K + and HCN channels in developing spiral ganglion neurons is mediated by cochlear inner hair cells. J Physiol 2024. [PMID: 39324853 DOI: 10.1113/jp286134] [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: 12/14/2023] [Accepted: 09/02/2024] [Indexed: 09/27/2024] Open
Abstract
Spiral ganglion neurons (SGNs) are primary sensory afferent neurons that relay acoustic information from the cochlear inner hair cells (IHCs) to the brainstem. The response properties of different SGNs diverge to represent a wide range of sound intensities in an action-potential code. This biophysical heterogeneity is established during pre-hearing stages of development, a time when IHCs fire spontaneous Ca2+ action potentials that drive glutamate release from their ribbon synapses onto the SGN terminals. The role of spontaneous IHC activity in the refinement of SGN characteristics is still largely unknown. Using pre-hearing otoferlin knockout mice (Otof-/-), in which Ca2+-dependent exocytosis in IHCs is abolished, we found that developing SGNs fail to upregulate low-voltage-activated K+-channels and hyperpolarisation-activated cyclic-nucleotide-gated channels. This delayed maturation resulted in hyperexcitable SGNs with immature firing characteristics. We have also shown that SGNs that synapse with the pillar side of the IHCs selectively express a resurgent K+ current, highlighting a novel biophysical marker for these neurons. RNA-sequencing showed that several K+ channels are downregulated in Otof-/- mice, further supporting the electrophysiological recordings. Our data demonstrate that spontaneous Ca2+-dependent activity in pre-hearing IHCs regulates some of the key biophysical and molecular features of the developing SGNs. KEY POINTS: Ca2+-dependent exocytosis in inner hair cells (IHCs) is otoferlin-dependent as early as postnatal day 1. A lack of otoferlin in IHCs affects potassium channel expression in SGNs. The absence of otoferlin is associated with SGN hyperexcitability. We propose that type I spiral ganglion neuron functional maturation depends on IHC exocytosis.
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Affiliation(s)
- Linus J Conrad
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Fiorella C Grandi
- INSERM, Institute de Myologie, Centre de Recherche en Myologie F-75013, Sorbonne Université, Paris, France
| | - Adam J Carlton
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Jing-Yi Jeng
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Lara de Tomasi
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Patryk Zarecki
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Walter Marcotti
- School of Biosciences, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Stuart L Johnson
- School of Biosciences, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Sheffield, UK
| | - Mirna Mustapha
- School of Biosciences, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Sheffield, UK
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2
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Arshavsky YI. Autoimmune hypothesis of Alzheimer's disease: unanswered question. J Neurophysiol 2024; 132:929-942. [PMID: 39163023 DOI: 10.1152/jn.00259.2024] [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: 06/18/2024] [Revised: 07/24/2024] [Accepted: 07/25/2024] [Indexed: 08/21/2024] Open
Abstract
Alzheimer's disease (AD) was described more than a century ago. However, there are still no effective approaches to its treatment, which may suggest that the search for the cure is not being conducted in the most productive direction. AD begins as selective impairments of declarative memory with no deficits in other cognitive functions. Therefore, understanding of the AD pathogenesis has to include the understanding of this selectivity. Currently, the main efforts aimed at prevention and treatment of AD are based on the dominating hypothesis for the AD pathogenesis: the amyloid hypothesis. But this hypothesis does not explain selective memory impairments since β-amyloid accumulates extracellularly and should be toxic to all types of cerebral neurons, not only to "memory engram neurons." To explain selective memory impairment, I propose the autoimmune hypothesis of AD, based on the analysis of risk factors for AD and molecular mechanisms of memory formation. Memory formation is associated with epigenetic modifications of chromatin in memory engram neurons and, therefore, might be accompanied by the expression of memory-specific proteins recognized by the adaptive immune system as "non-self" antigens. Normally, the brain is protected by the blood-brain barrier (BBB). All risk factors for AD provoke BBB disruptions, possibly leading to an autoimmune reaction against memory engram neurons. This reaction would make them selectively sensitive to tauopathy. If this hypothesis is confirmed, the strategies for AD prevention and treatment would be radically changed.
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Affiliation(s)
- Yuri I Arshavsky
- BioCircuits Institute, University of California, San Diego, La Jolla, California, United States
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3
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Bian Y, Kawabata R, Enwright JF, Tsubomoto M, Okuda T, Kamikawa K, Kimoto S, Kikuchi M, Lewis DA, Hashimoto T. Expression of activity-regulated transcripts in pyramidal neurons across the cortical visuospatial working memory network in unaffected comparison individuals and individuals with schizophrenia. Psychiatry Res 2024; 339:116084. [PMID: 39033685 DOI: 10.1016/j.psychres.2024.116084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 07/03/2024] [Accepted: 07/10/2024] [Indexed: 07/23/2024]
Abstract
Visuospatial working memory (vsWM), which is impaired in schizophrenia (SZ), is mediated by multiple cortical regions including the primary (V1) and association (V2) visual, posterior parietal (PPC) and dorsolateral prefrontal (DLPFC) cortices. In these regions, parvalbumin (PV) or somatostatin (SST) GABA neurons are altered in SZ as reflected in lower levels of activity-regulated transcripts. As PV and SST neurons receive excitatory inputs from neighboring pyramidal neurons, we hypothesized that levels of activity-regulated transcripts are also lower in pyramidal neurons in these regions. Thus, we quantified levels of four activity-regulated, pyramidal neuron-selective transcripts, namely adenylate cyclase-activating polypeptide-1 (ADCYAP1), brain-derived neurotrophic factor (BDNF), neuronal pentraxin-2 (NPTX2) and neuritin-1 (NRN1) mRNAs, in V1, V2, PPC and DLPFC from unaffected comparison and SZ individuals. In SZ, BDNF and NPTX2 mRNA levels were lower across all four regions, whereas ADCYAP1 and NRN1 mRNA levels were lower in V1 and V2. The regional pattern of deficits in BDNF and NPTX2 mRNAs was similar to that in transcripts in PV and SST neurons in SZ. These findings suggest that lower activity of pyramidal neurons expressing BDNF and/or NPTX2 mRNAs might contribute to alterations in PV and SST neurons across the vsWM network in SZ.
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Affiliation(s)
- Yufan Bian
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - Rika Kawabata
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - John F Enwright
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Makoto Tsubomoto
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - Takeshi Okuda
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan
| | - Kohei Kamikawa
- Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, 634-8521, Japan
| | - Sohei Kimoto
- Department of Psychiatry, Nara Medical University School of Medicine, Kashihara, 634-8521, Japan; Department of Neuropsychiatry, Wakayama Medical University School of Medicine, Wakayama, 641-8509, Japan
| | - Mitsuru Kikuchi
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan; Research Center for Child Development, Kanazawa University, Kanazawa 920-8640, Japan
| | - David A Lewis
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA; Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15213, USA.
| | - Takanori Hashimoto
- Department of Psychiatry and Behavioral Science, Kanazawa University Graduate School of Medical Sciences, Kanazawa, 920-8640, Japan; Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA; National Hospital Organization Hokuriku Hospital, Nanto, 939-1893, Japan.
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Prince GS, Reynolds M, Martina V, Sun H. Gene-environmental regulation of the postnatal post-mitotic neuronal maturation. Trends Genet 2024; 40:480-494. [PMID: 38658255 PMCID: PMC11153025 DOI: 10.1016/j.tig.2024.03.006] [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: 01/30/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/26/2024]
Abstract
Embryonic neurodevelopment, particularly neural progenitor differentiation into post-mitotic neurons, has been extensively studied. While the number and composition of post-mitotic neurons remain relatively constant from birth to adulthood, the brain undergoes significant postnatal maturation marked by major property changes frequently disrupted in neural diseases. This review first summarizes recent characterizations of the functional and molecular maturation of the postnatal nervous system. We then review regulatory mechanisms controlling the precise gene expression changes crucial for the intricate sequence of maturation events, highlighting experience-dependent versus cell-intrinsic genetic timer mechanisms. Despite significant advances in understanding of the gene-environmental regulation of postnatal neuronal maturation, many aspects remain unknown. The review concludes with our perspective on exciting future research directions in the next decade.
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Affiliation(s)
- Gabrielle S Prince
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Molly Reynolds
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Verdion Martina
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - HaoSheng Sun
- Department of Cell, Developmental, and Integrative Biology, The University of Alabama at Birmingham, Birmingham, AL, USA; Freeman Hrabowski Scholar, Howard Hughes Medical Institute, Chevy Chase, MD, USA.
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Nakashima A, Takeuchi H. Shaping the olfactory map: cell type-specific activity patterns guide circuit formation. Front Neural Circuits 2024; 18:1409680. [PMID: 38860141 PMCID: PMC11163119 DOI: 10.3389/fncir.2024.1409680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Accepted: 04/30/2024] [Indexed: 06/12/2024] Open
Abstract
The brain constructs spatially organized sensory maps to represent sensory information. The formation of sensory maps has traditionally been thought to depend on synchronous neuronal activity. However, recent evidence from the olfactory system suggests that cell type-specific temporal patterns of spontaneous activity play an instructive role in shaping the olfactory glomerular map. These findings challenge traditional views and highlight the importance of investigating the spatiotemporal dynamics of neural activity to understand the development of complex neural circuits. This review discusses the implications of new findings in the olfactory system and outlines future research directions.
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Affiliation(s)
- Ai Nakashima
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Haruki Takeuchi
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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Zachariou M, Loizidou EM, Spyrou GM. Immediate-Early Genes as Influencers in Genetic Networks and their Role in Alzheimer's Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.29.586739. [PMID: 38585978 PMCID: PMC10996630 DOI: 10.1101/2024.03.29.586739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Immediate-early genes (IEGs) are a class of activity-regulated genes (ARGs) that are transiently and rapidly activated in the absence of de novo protein synthesis in response to neuronal activity. We explored the role of IEGs in genetic networks to pinpoint potential drug targets for Alzheimer's disease (AD). Using a combination of network analysis and genome-wide association study (GWAS) summary statistics we show that (1) IEGs exert greater topological influence across different human and mouse gene networks compared to other ARGs, (2) ARGs are sparsely involved in diseases and significantly more mutational constrained compared to non-ARGs, (3) Many AD-linked variants are in ARGs gene regions, mainly in MARK4 near FOSB, with an AD risk eQTL that increases MARK4 expression in cortical areas, (4) MARK4 holds an influential place in a dense AD multi-omic network and a high AD druggability score. Our work on IEGs' influential network role is a valuable contribution to guiding interventions for diseases marked by dysregulation of their downstream targets and highlights MARK4 as a promising underexplored AD-target.
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Affiliation(s)
| | - Eleni M Loizidou
- biobank.cy, Center of Excellence in Biobanking and Biomedical Research, University of Cyprus
| | - George M Spyrou
- Bioinformatics Department, The Cyprus Institute of Neurology and Genetics
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González-González MA, Conde SV, Latorre R, Thébault SC, Pratelli M, Spitzer NC, Verkhratsky A, Tremblay MÈ, Akcora CG, Hernández-Reynoso AG, Ecker M, Coates J, Vincent KL, Ma B. Bioelectronic Medicine: a multidisciplinary roadmap from biophysics to precision therapies. Front Integr Neurosci 2024; 18:1321872. [PMID: 38440417 PMCID: PMC10911101 DOI: 10.3389/fnint.2024.1321872] [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: 10/16/2023] [Accepted: 01/10/2024] [Indexed: 03/06/2024] Open
Abstract
Bioelectronic Medicine stands as an emerging field that rapidly evolves and offers distinctive clinical benefits, alongside unique challenges. It consists of the modulation of the nervous system by precise delivery of electrical current for the treatment of clinical conditions, such as post-stroke movement recovery or drug-resistant disorders. The unquestionable clinical impact of Bioelectronic Medicine is underscored by the successful translation to humans in the last decades, and the long list of preclinical studies. Given the emergency of accelerating the progress in new neuromodulation treatments (i.e., drug-resistant hypertension, autoimmune and degenerative diseases), collaboration between multiple fields is imperative. This work intends to foster multidisciplinary work and bring together different fields to provide the fundamental basis underlying Bioelectronic Medicine. In this review we will go from the biophysics of the cell membrane, which we consider the inner core of neuromodulation, to patient care. We will discuss the recently discovered mechanism of neurotransmission switching and how it will impact neuromodulation design, and we will provide an update on neuronal and glial basis in health and disease. The advances in biomedical technology have facilitated the collection of large amounts of data, thereby introducing new challenges in data analysis. We will discuss the current approaches and challenges in high throughput data analysis, encompassing big data, networks, artificial intelligence, and internet of things. Emphasis will be placed on understanding the electrochemical properties of neural interfaces, along with the integration of biocompatible and reliable materials and compliance with biomedical regulations for translational applications. Preclinical validation is foundational to the translational process, and we will discuss the critical aspects of such animal studies. Finally, we will focus on the patient point-of-care and challenges in neuromodulation as the ultimate goal of bioelectronic medicine. This review is a call to scientists from different fields to work together with a common endeavor: accelerate the decoding and modulation of the nervous system in a new era of therapeutic possibilities.
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Affiliation(s)
- María Alejandra González-González
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, United States
- Department of Pediatric Neurology, Baylor College of Medicine, Houston, TX, United States
| | - Silvia V. Conde
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, NOVA University, Lisbon, Portugal
| | - Ramon Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Stéphanie C. Thébault
- Laboratorio de Investigación Traslacional en salud visual (D-13), Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Querétaro, Mexico
| | - Marta Pratelli
- Neurobiology Department, Kavli Institute for Brain and Mind, UC San Diego, La Jolla, CA, United States
| | - Nicholas C. Spitzer
- Neurobiology Department, Kavli Institute for Brain and Mind, UC San Diego, La Jolla, CA, United States
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, China
- International Collaborative Center on Big Science Plan for Purinergic Signaling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
| | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montreal, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
| | - Cuneyt G. Akcora
- Department of Computer Science, University of Central Florida, Orlando, FL, United States
| | | | - Melanie Ecker
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | | | - Kathleen L. Vincent
- Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, TX, United States
| | - Brandy Ma
- Stanley H. Appel Department of Neurology, Houston Methodist Hospital, Houston, TX, United States
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Atsumi Y, Iwata R, Kimura H, Vanderhaeghen P, Yamamoto N, Sugo N. Repetitive CREB-DNA interactions at gene loci predetermined by CBP induce activity-dependent gene expression in human cortical neurons. Cell Rep 2024; 43:113576. [PMID: 38128530 DOI: 10.1016/j.celrep.2023.113576] [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: 05/23/2023] [Revised: 11/10/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
Neuronal activity-dependent transcription plays a key role in plasticity and pathology in the brain. An intriguing question is how neuronal activity controls gene expression via interactions of transcription factors with DNA and chromatin modifiers in the nucleus. By utilizing single-molecule imaging in human embryonic stem cell (ESC)-derived cortical neurons, we demonstrate that neuronal activity increases repetitive emergence of cAMP response element-binding protein (CREB) at histone acetylation sites in the nucleus, where RNA polymerase II (RNAPII) accumulation and FOS expression occur rapidly. Neuronal activity also enhances co-localization of CREB and CREB-binding protein (CBP). Increased binding of a constitutively active CREB to CBP efficiently induces CREB repetitive emergence. On the other hand, the formation of histone acetylation sites is dependent on CBP histone modification via acetyltransferase (HAT) activity but is not affected by neuronal activity. Taken together, our results suggest that neuronal activity promotes repetitive CREB-CRE and CREB-CBP interactions at predetermined histone acetylation sites, leading to rapid gene expression.
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Affiliation(s)
- Yuri Atsumi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan
| | - Ryohei Iwata
- VIB-KU Leuven, Center for Brain & Disease Research and KU Leuven, Department of Neurosciences & Leuven Brain Institute, 3000 Leuven, Belgium
| | - Hiroshi Kimura
- Cell Biology Center, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8503, Japan
| | - Pierre Vanderhaeghen
- VIB-KU Leuven, Center for Brain & Disease Research and KU Leuven, Department of Neurosciences & Leuven Brain Institute, 3000 Leuven, Belgium
| | - Nobuhiko Yamamoto
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan; Institute of Neurological and Psychiatric Disorders, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518132, China.
| | - Noriyuki Sugo
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka 565-0871, Japan.
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