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Ray A, Loghinov I, Ravindranath V, Barth AL. Early hippocampal hyperexcitability and synaptic reorganization in mouse models of amyloidosis. iScience 2024; 27:110629. [PMID: 39262788 PMCID: PMC11388185 DOI: 10.1016/j.isci.2024.110629] [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: 01/30/2024] [Revised: 05/09/2024] [Accepted: 07/29/2024] [Indexed: 09/13/2024] Open
Abstract
The limited success of plaque-reducing therapies in Alzheimer's disease suggests that early treatment might be more effective in delaying or reversing memory impairments. Toward this end, it is important to establish the progression of synaptic and circuit changes before onset of plaques or cognitive deficits. Here, we used quantitative, fluorescence-based methods for synapse detection in CA1 pyramidal neurons to investigate the interaction between abnormal circuit activity, measured by Fos-immunoreactivity, and synapse reorganization in mouse models of amyloidosis. Using a genetically encoded, fluorescently labeled synaptic marker in juvenile mice (prior to sexual maturity), we find both synapse gain and loss depending on dendritic location. This progresses to broad synapse loss in aged mice. Elevated hippocampal activity in both CA3 and CA1 was present at weaning and preceded this reorganization. Thus, Aβ overproduction may initiate abnormal activity and subsequent input-specific synapse plasticity. These findings indicate that sustained amyloidosis drives heterogeneous and progressive circuit-wide abnormalities.
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Affiliation(s)
- Ajit Ray
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Iulia Loghinov
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Vijayalakshmi Ravindranath
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, Karnataka 560012, India
- Centre for Brain Research, Indian Institute of Science, Bengaluru, Karnataka 560012, India
| | - Alison L Barth
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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Velázquez-Delgado C, Hernández-Ortiz E, Landa-Navarro L, Tapia-Rodríguez M, Moreno-Castilla P, Bermúdez-Rattoni F. Repeated exposure to novelty promotes resilience against the amyloid-beta effect through dopaminergic stimulation. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06650-5. [PMID: 39145803 DOI: 10.1007/s00213-024-06650-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 07/07/2024] [Indexed: 08/16/2024]
Abstract
RATIONALE The accumulation of beta-amyloid peptide (Aβ) in the forebrain leads to cognitive dysfunction and neurodegeneration in Alzheimer's disease. Studies have shown that individuals with a consistently cognitively active lifestyle are less vulnerable to Aβ toxicity. Recent research has demonstrated that intrahippocampal Aβ can impact catecholaminergic release and spatial memory. Interestingly, exposure to novelty stimuli has been found to stimulate the release of catecholamines in the hippocampus. However, it remains uncertain whether repeated enhancing catecholamine activity can effectively alleviate cognitive impairment in individuals with Alzheimer's disease. OBJECTIVES Our primary aim was to investigate whether repeated exposure to novelty could enable cognitive resilience against Aβ. This protection could be achieved by modulating catecholaminergic activity within the hippocampus. METHODS To investigate this hypothesis, we subjected mice to three different conditions-standard housing (SH), repeated novelty (Nov), or daily social interaction (Soc) for one month. We then infused saline solution (SS) or Aβ (Aβ1-42) oligomers intrahippocampally and measured spatial memory retrieval in a Morris Water Maze (MWM). Stereological analysis and extracellular baseline dopamine levels using in vivo microdialysis were assessed in independent groups of mice. RESULTS The mice that received Aβ1-42 intrahippocampal infusions and remained in SH or Soc conditions showed impaired spatial memory retrieval. In contrast, animals subjected to the Nov protocol demonstrated remarkable resilience, showing strong spatial memory expression even after Aβ1-42 intrahippocampal infusion. The stereological analysis indicated that the Aβ1-42 infusion reduced the tyrosine hydroxylase axonal length in SH or Soc mice compared to the Nov group. Accordingly, the hippocampal extracellular dopamine levels increased significantly in the Nov groups. CONCLUSIONS These compelling results demonstrate the potential for repeated novelty exposure to strengthen the dopaminergic system and mitigate the toxic effects of Aβ1-42. They also highlight new and promising therapeutic avenues for treating and preventing AD, especially in its early stages.
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Affiliation(s)
- Cintia Velázquez-Delgado
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Eduardo Hernández-Ortiz
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Lucia Landa-Navarro
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Miguel Tapia-Rodríguez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico
| | - Perla Moreno-Castilla
- Laboratory of Cognitive Resilience, Center of Aging Research (CIE), Center for Research and Advanced Studies of the National Polytechnic Institute, CINVESTAV, Mexico City, Mexico.
| | - Federico Bermúdez-Rattoni
- División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, 04510, Mexico City, Mexico.
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Goniotaki D, Tamagnini F, Biasetti L, Rumpf S, Troakes C, Pollack SJ, Ukwesa S, Sun H, Kraev I, Serpell LC, Noble W, Staras K, Hanger DP. Tau-mediated synaptic dysfunction is coupled with HCN channelopathy. Alzheimers Dement 2024; 20:5629-5646. [PMID: 38994745 PMCID: PMC11350046 DOI: 10.1002/alz.14074] [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: 01/29/2024] [Revised: 05/01/2024] [Accepted: 05/25/2024] [Indexed: 07/13/2024]
Abstract
INTRODUCTION In tauopathies, altered tau processing correlates with impairments in synaptic density and function. Changes in hyperpolarization-activated cyclic nucleotide-gated (HCN) channels contribute to disease-associated abnormalities in multiple neurodegenerative diseases. METHODS To investigate the link between tau and HCN channels, we performed histological, biochemical, ultrastructural, and functional analyses of hippocampal tissues from Alzheimer's disease (AD), age-matched controls, Tau35 mice, and/or Tau35 primary hippocampal neurons. RESULTS Expression of specific HCN channels is elevated in post mortem AD hippocampus. Tau35 mice develop progressive abnormalities including increased phosphorylated tau, enhanced HCN channel expression, decreased dendritic branching, reduced synapse density, and vesicle clustering defects. Tau35 primary neurons show increased HCN channel expression enhanced hyperpolarization-induced membrane voltage "sag" and changes in the frequency and kinetics of spontaneous excitatory postsynaptic currents. DISCUSSION Our findings are consistent with a model in which pathological changes in tauopathies impact HCN channels to drive network-wide structural and functional synaptic deficits. HIGHLIGHTS Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are functionally linked to the development of tauopathy. Expression of specific HCN channels is elevated in the hippocampus in Alzheimer's disease and the Tau35 mouse model of tauopathy. Increased expression of HCN channels in Tau35 mice is accompanied by hyperpolarization-induced membrane voltage "sag" demonstrating a detrimental effect of tau abnormalities on HCN channel function. Tau35 expression alters synaptic organization, causing a loosened vesicle clustering phenotype in Tau35 mice.
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Affiliation(s)
- Despoina Goniotaki
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Francesco Tamagnini
- Department of PharmacySchool of ChemistryFood and PharmacyUniversity of ReadingReadingUK
| | - Luca Biasetti
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - Svenja‐Lotta Rumpf
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Claire Troakes
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Saskia J. Pollack
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Shalom Ukwesa
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Haoyue Sun
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
| | - Igor Kraev
- Electron Microscopy SuiteSTEM FacultyThe Open UniversityMilton KeynesUK
| | - Louise C. Serpell
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - Wendy Noble
- Department of Clinical and Biomedical SciencesUniversity of ExeterExeterUK
| | - Kevin Staras
- Sussex NeuroscienceSchool of Life SciencesUniversity of SussexBrightonUK
| | - Diane P. Hanger
- Department of Basic and Clinical NeuroscienceInstitute of PsychiatryPsychology & NeuroscienceMaurice Wohl Clinical Neuroscience InstituteKing's College LondonLondonUK
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Bettamin L, Mathieu F, Marty FH, Blatche MC, Gonzalez-Dunia D, Suberbielle E, Larrieu G. Real-Time and High-Resolution Monitoring of Neuronal Electrical Activity and pH Variations Based on the Co-Integration of Nanoelectrodes and Chem-FinFETs. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2309055. [PMID: 38552225 DOI: 10.1002/smll.202309055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 03/18/2024] [Indexed: 07/05/2024]
Abstract
Developing new approaches amenable to the measurement of neuronal physiology in real-time is a very active field of investigation, as it will offer improved methods to assess the impact of diverse insults on neuronal homeostasis. Here, the development of an in vitro bio platform is reported which can record the electrical activity of cultured primary rat cortical neurons with extreme sensitivity, while simultaneously tracking the localized changes in the pH of the culture medium. This bio platform features passive vertical nanoprobes with ultra-high signal resolution (several mV amplitude ranges) and Chem-FinFETs (pH sensitivity of sub-0.1 pH units), covering an area as little as a neuronal soma. These multi-sensing units are arranged in an array to probe both chemically and electrically an equivalent surface of ≈ 0.5 mm2. A homemade setup is also developed which allows recording of multiplexed data in real-time (10 ps range) from the active chem-sensors and passive electrodes and which is used to operate the platform. Finally, a proof-of-concept is presented for a neuro-relevant application, by investigating the effect on neuronal activity of Amyloid beta oligomers, the main toxic peptide in Alzheimer's Disease, which reveals that exposure to amyloid beta oligomers modify the amplitude, but not the frequency, of neuronal firing, without any detectable changes in pH values along this process.
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Affiliation(s)
- Luca Bettamin
- LAAS-CNRS, CNRS, Université de Toulouse, Toulouse, 31031, France
- INFINITY, INSERM, CNRS, Université de Toulouse, Toulouse, 31031, France
| | - Fabrice Mathieu
- LAAS-CNRS, CNRS, Université de Toulouse, Toulouse, 31031, France
| | - Florent H Marty
- INFINITY, INSERM, CNRS, Université de Toulouse, Toulouse, 31031, France
| | | | | | - Elsa Suberbielle
- INFINITY, INSERM, CNRS, Université de Toulouse, Toulouse, 31031, France
| | - Guilhem Larrieu
- LAAS-CNRS, CNRS, Université de Toulouse, Toulouse, 31031, France
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Armijo-Weingart L, San Martin L, Gallegos S, Araya A, Konar-Nie M, Fernandez-Pérez E, Aguayo LG. Loss of glycine receptors in the nucleus accumbens and ethanol reward in an Alzheimer´s Disease mouse model. Prog Neurobiol 2024; 237:102616. [PMID: 38723884 PMCID: PMC11163974 DOI: 10.1016/j.pneurobio.2024.102616] [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: 11/29/2023] [Revised: 03/21/2024] [Accepted: 05/01/2024] [Indexed: 05/12/2024]
Abstract
Alterations in cognitive and non-cognitive cerebral functions characterize Alzheimer's disease (AD). Cortical and hippocampal impairments related to extracellular accumulation of Aβ in AD animal models have been extensively investigated. However, recent reports have also implicated intracellular Aβ in limbic regions, such as the nucleus accumbens (nAc). Accumbal neurons express high levels of inhibitory glycine receptors (GlyRs) that are allosterically modulated by ethanol and have a role in controlling its intake. In the present study, we investigated how GlyRs in the 2xTg mice (AD model) affect nAc functions and ethanol intake behavior. Using transgenic and control aged-matched litter mates, we found that the GlyRα2 subunit was significantly decreased in AD mice (6-month-old). We also examined intracellular calcium dynamics using the fluorescent calcium protein reporter GCaMP in slice photometry. We also found that the calcium signal mediated by GlyRs, but not GABAAR, was also reduced in AD neurons. Additionally, ethanol potentiation was significantly decreased in accumbal neurons in the AD mice. Finally, we performed drinking in the dark (DID) experiments and found that 2xTg mice consumed less ethanol on the last day of DID, in agreement with a lower blood ethanol concentration. 2xTg mice also showed lower sucrose consumption, indicating that overall food reward was altered. In conclusion, the data support the role of GlyRs in nAc neuron excitability and a decreased glycinergic activity in the 2xTg mice that might lead to impairment in reward processing at an early stage of the disease.
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Affiliation(s)
- Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Loreto San Martin
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Scarlet Gallegos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Anibal Araya
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Macarena Konar-Nie
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Eduardo Fernandez-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile.
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Berkowitz BA, Paruchuri A, Stanek J, Abdul-Nabi M, Podolsky RH, Bustos AH, Childers KL, Murphy GG, Stangis K, Roberts R. Biomarker evidence of early vision and rod energy-linked pathophysiology benefits from very low dose DMSO in 5xFAD mice. Acta Neuropathol Commun 2024; 12:85. [PMID: 38822433 PMCID: PMC11140992 DOI: 10.1186/s40478-024-01799-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/20/2024] [Indexed: 06/03/2024] Open
Abstract
Here, we test whether early visual and OCT rod energy-linked biomarkers indicating pathophysiology in nicotinamide nucleotide transhydrogenase (Nnt)-null 5xFAD mice also occur in Nnt-intact 5xFAD mice and whether these biomarkers can be pharmacologically treated. Four-month-old wild-type or 5xFAD C57BL/6 substrains with either a null (B6J) Nnt or intact Nnt gene (B6NTac) and 5xFAD B6J mice treated for one month with either R-carvedilol + vehicle or only vehicle (0.01% DMSO) were studied. The contrast sensitivity (CS), external limiting membrane-retinal pigment epithelium (ELM-RPE) thickness (a proxy for low pH-triggered water removal), profile shape of the hyperreflective band just posterior to the ELM (i.e., the mitochondrial configuration within photoreceptors per aspect ratio [MCP/AR]), and retinal laminar thickness were measured. Both wild-type substrains showed similar visual performance indices and dark-evoked ELM-RPE contraction. The lack of a light-dark change in B6NTac MCP/AR, unlike in B6J mice, is consistent with relatively greater mitochondrial efficiency. 5xFAD B6J mice, but not 5xFAD B6NTac mice, showed lower-than-WT CS. Light-adapted 5xFAD substrains both showed abnormal ELM-RPE contraction and greater-than-WT MCP/AR contraction. The inner retina and superior outer retina were thinner. Treating 5xFAD B6J mice with R-carvedilol + DMSO or DMSO alone corrected CS and ELM-RPE contraction but not supernormal MCP/AR contraction or laminar thinning. These results provide biomarker evidence for prodromal photoreceptor mitochondrial dysfunction/oxidative stress/oxidative damage, which is unrelated to visual performance, as well as the presence of the Nnt gene. This pathophysiology is druggable in 5xFAD mice.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA.
| | - Anuhya Paruchuri
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Josh Stanek
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Mura Abdul-Nabi
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
| | - Robert H Podolsky
- Biostatistics and Study Methodology, Children's National Hospital, Silver Spring, MD, USA
| | | | | | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Katherine Stangis
- Michigan Neuroscience Institute, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robin Roberts
- Department of Ophthalmology, Visual and Anatomical Sciences, Wayne State University School of Medicine, 540 E. Canfield, Detroit, MI, 48201, USA
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Vajaria R, Davis D, Thaweepanyaporn K, Dovey J, Nasuto S, Delivopoulos E, Tamagnini F, Knight P, Vasudevan N. Estrogen and testosterone secretion from the mouse brain. Steroids 2024; 204:109398. [PMID: 38513983 DOI: 10.1016/j.steroids.2024.109398] [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: 11/15/2023] [Revised: 03/17/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024]
Abstract
Estrogen and testosterone are typically thought of as gonadal or adrenal derived steroids that cross the blood brain barrier to signal via both rapid nongenomic and slower genomic signalling pathways. Estrogen and testosterone signalling has been shown to drive interlinked behaviours such as social behaviours and cognition by binding to their cognate receptors in hypothalamic and forebrain nuclei. So far, acute brain slices have been used to study short-term actions of 17β-estradiol, typically using electrophysiological measures. For example, these techniques have been used to investigate, nongenomic signalling by estrogen such as the estrogen modulation of long-term potentiation (LTP) in the hippocampus. Using a modified method that preserves the slice architecture, we show, for the first time, that acute coronal slices from the prefrontal cortex and from the hypothalamus maintained in aCSF over longer periods i.e. 24 h can be steroidogenic, increasing their secretion of testosterone and estrogen. We also show that the hypothalamic nuclei produce more estrogen and testosterone than the prefrontal cortex. Therefore, this extended acute slice system can be used to study the regulation of steroid production and secretion by discrete nuclei in the brain.
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Affiliation(s)
- Ruby Vajaria
- School of Biological Sciences, University of Reading, Reading, UK
| | - DeAsia Davis
- School of Biological Sciences, University of Reading, Reading, UK
| | | | - Janine Dovey
- School of Biological Sciences, University of Reading, Reading, UK
| | - Slawomir Nasuto
- School of Biological Sciences, University of Reading, Reading, UK
| | | | | | - Philip Knight
- School of Biological Sciences, University of Reading, Reading, UK
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Saghafi S, Rumbell T, Gurev V, Kozloski J, Tamagnini F, Wedgwood KCA, Diekman CO. Inferring Parameters of Pyramidal Neuron Excitability in Mouse Models of Alzheimer's Disease Using Biophysical Modeling and Deep Learning. Bull Math Biol 2024; 86:46. [PMID: 38528167 PMCID: PMC10963524 DOI: 10.1007/s11538-024-01273-5] [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: 02/28/2023] [Accepted: 02/19/2024] [Indexed: 03/27/2024]
Abstract
Alzheimer's disease (AD) is believed to occur when abnormal amounts of the proteins amyloid beta and tau aggregate in the brain, resulting in a progressive loss of neuronal function. Hippocampal neurons in transgenic mice with amyloidopathy or tauopathy exhibit altered intrinsic excitability properties. We used deep hybrid modeling (DeepHM), a recently developed parameter inference technique that combines deep learning with biophysical modeling, to map experimental data recorded from hippocampal CA1 neurons in transgenic AD mice and age-matched wildtype littermate controls to the parameter space of a conductance-based CA1 model. Although mechanistic modeling and machine learning methods are by themselves powerful tools for approximating biological systems and making accurate predictions from data, when used in isolation these approaches suffer from distinct shortcomings: model and parameter uncertainty limit mechanistic modeling, whereas machine learning methods disregard the underlying biophysical mechanisms. DeepHM addresses these shortcomings by using conditional generative adversarial networks to provide an inverse mapping of data to mechanistic models that identifies the distributions of mechanistic modeling parameters coherent to the data. Here, we demonstrated that DeepHM accurately infers parameter distributions of the conductance-based model on several test cases using synthetic data generated with complex underlying parameter structures. We then used DeepHM to estimate parameter distributions corresponding to the experimental data and infer which ion channels are altered in the Alzheimer's mouse models compared to their wildtype controls at 12 and 24 months. We found that the conductances most disrupted by tauopathy, amyloidopathy, and aging are delayed rectifier potassium, transient sodium, and hyperpolarization-activated potassium, respectively.
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Affiliation(s)
- Soheil Saghafi
- Department of Mathematical Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ, 07102, USA
- Department of Biomedical Informatics, School of Medicine, Emory University, Atlanta, GA, 30322, USA
| | - Timothy Rumbell
- IBM T.J. Watson Research Center, Yorktown Heights, NY, 10598, USA
| | | | - James Kozloski
- IBM T.J. Watson Research Center, Yorktown Heights, NY, 10598, USA
| | | | | | - Casey O Diekman
- Department of Mathematical Sciences, New Jersey Institute of Technology, University Heights, Newark, NJ, 07102, USA.
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Alcantara-Gonzalez D, Kennedy M, Criscuolo C, Botterill J, Scharfman HE. Increased excitability of dentate gyrus mossy cells occurs early in life in the Tg2576 model of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579729. [PMID: 38645244 PMCID: PMC11027210 DOI: 10.1101/2024.02.09.579729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
INTRODUCTION Hyperexcitability in Alzheimer's disease (AD) emerge early and contribute to disease progression. The dentate gyrus (DG) is implicated in hyperexcitability in AD. We hypothesized that mossy cells (MCs), regulators of DG excitability, contribute to early hyperexcitability in AD. Indeed, MCs generate hyperexcitability in epilepsy. METHODS Using the Tg2576 model and WT mice (∼1month-old), we compared MCs electrophysiologically, assessed c-Fos activity marker, Aβ expression and mice performance in a hippocampal-dependent memory task. RESULTS Tg2576 MCs exhibit increased spontaneous excitatory events and decreased inhibitory currents, increasing the charge transfer excitation/inhibition ratio. Tg2576 MC intrinsic excitability was enhanced, and showed higher c-Fos, intracellular Aβ expression, and axon sprouting. Granule cells only showed changes in synaptic properties, without intrinsic changes. The effects occurred before a memory task is affected. DISCUSSION Early electrophysiological and morphological alterations in Tg2576 MCs are consistent with enhanced excitability, suggesting an early role in DG hyperexcitability and AD pathophysiology. HIGHLIGHTS ∘ MCs from 1 month-old Tg2576 mice had increased spontaneous excitatory synaptic input. ∘ Tg2576 MCs had reduced spontaneous inhibitory synaptic input. ∘ Several intrinsic properties were abnormal in Tg2576 MCs. ∘ Tg2576 GCs had enhanced synaptic excitation but no changes in intrinsic properties. ∘ Tg2576 MCs exhibited high c-Fos expression, soluble Aβ and axonal sprouting.
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Dainauskas JJ, Vitale P, Moreno S, Marie H, Migliore M, Saudargiene A. Altered synaptic plasticity at hippocampal CA1-CA3 synapses in Alzheimer's disease: integration of amyloid precursor protein intracellular domain and amyloid beta effects into computational models. Front Comput Neurosci 2023; 17:1305169. [PMID: 38130706 PMCID: PMC10733499 DOI: 10.3389/fncom.2023.1305169] [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: 09/30/2023] [Accepted: 11/07/2023] [Indexed: 12/23/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive memory loss and cognitive dysfunction brain disorder brought on by the dysfunctional amyloid precursor protein (APP) processing and clearance of APP peptides. Increased APP levels lead to the production of AD-related peptides including the amyloid APP intracellular domain (AICD) and amyloid beta (Aβ), and consequently modify the intrinsic excitability of the hippocampal CA1 pyramidal neurons, synaptic protein activity, and impair synaptic plasticity at hippocampal CA1-CA3 synapses. The goal of the present study is to build computational models that incorporate the effect of AD-related peptides on CA1 pyramidal neuron and hippocampal synaptic plasticity under the AD conditions and investigate the potential pharmacological treatments that could normalize hippocampal synaptic plasticity and learning in AD. We employ a phenomenological N-methyl-D-aspartate (NMDA) receptor-based voltage-dependent synaptic plasticity model that includes the separate receptor contributions on long-term potentiation (LTP) and long-term depression (LTD) and embed it into the a detailed compartmental model of CA1 pyramidal neuron. Modeling results show that partial blockade of Glu2NB-NMDAR-gated channel restores intrinsic excitability of a CA1 pyramidal neuron and rescues LTP in AICD and Aβ conditions. The model provides insight into the complex interactions in AD pathophysiology and suggests the conditions under which the synchronous activation of a cluster of synaptic inputs targeting the dendritic tree of CA1 pyramidal neuron leads to restored synaptic plasticity.
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Affiliation(s)
- Justinas J. Dainauskas
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Informatics, Vytautas Magnus University, Kaunas, Lithuania
| | - Paola Vitale
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Sebastien Moreno
- Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Hélène Marie
- Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS), Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Valbonne, France
| | - Michele Migliore
- Institute of Biophysics, National Research Council, Palermo, Italy
| | - Ausra Saudargiene
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania
- Department of Informatics, Vytautas Magnus University, Kaunas, Lithuania
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Meftah S, Gan J. Alzheimer's disease as a synaptopathy: Evidence for dysfunction of synapses during disease progression. Front Synaptic Neurosci 2023; 15:1129036. [PMID: 36970154 PMCID: PMC10033629 DOI: 10.3389/fnsyn.2023.1129036] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/23/2023] [Indexed: 03/11/2023] Open
Abstract
The synapse has consistently been considered a vulnerable and critical target within Alzheimer's disease, and synapse loss is, to date, one of the main biological correlates of cognitive decline within Alzheimer's disease. This occurs prior to neuronal loss with ample evidence that synaptic dysfunction precedes this, in support of the idea that synaptic failure is a crucial stage within disease pathogenesis. The two main pathological hallmarks of Alzheimer's disease, abnormal aggregates of amyloid or tau proteins, have had demonstrable effects on synaptic physiology in animal and cellular models of Alzheimer's disease. There is also growing evidence that these two proteins may have a synergistic effect on neurophysiological dysfunction. Here, we review some of the main findings of synaptic alterations in Alzheimer's disease, and what we know from Alzheimer's disease animal and cellular models. First, we briefly summarize some of the human evidence to suggest that synapses are altered, including how this relates to network activity. Subsequently, animal and cellular models of Alzheimer's disease are considered, highlighting mouse models of amyloid and tau pathology and the role these proteins may play in synaptic dysfunction, either in isolation or examining how the two pathologies may interact in dysfunction. This specifically focuses on neurophysiological function and dysfunction observed within these animal models, typically measured using electrophysiology or calcium imaging. Following synaptic dysfunction and loss, it would be impossible to imagine that this would not alter oscillatory activity within the brain. Therefore, this review also discusses how this may underpin some of the aberrant oscillatory patterns seen in animal models of Alzheimer's disease and human patients. Finally, an overview of some key directions and considerations in the field of synaptic dysfunction in Alzheimer's disease is covered. This includes current therapeutics that are targeted specifically at synaptic dysfunction, but also methods that modulate activity to rescue aberrant oscillatory patterns. Other important future avenues of note in this field include the role of non-neuronal cell types such as astrocytes and microglia, and mechanisms of dysfunction independent of amyloid and tau in Alzheimer's disease. The synapse will certainly continue to be an important target within Alzheimer's disease for the foreseeable future.
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Affiliation(s)
- Soraya Meftah
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Jian Gan
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
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12
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Yavorsky VA, Rozumna NM, Lukyanetz EA. Influence of amyloid beta on impulse spiking of isolated hippocampal neurons. Front Cell Neurosci 2023; 17:1132092. [PMID: 37124394 PMCID: PMC10133472 DOI: 10.3389/fncel.2023.1132092] [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: 12/26/2022] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
One of the signs of Alzheimer's disease (AD) is the formation of β-amyloid plaques, which ultimately lead to the dysfunction of neurons with subsequent neurodegeneration. Although extensive researches have been conducted on the effects of different amyloid conformations such as oligomers and fibrils on neuronal function in isolated cells and circuits, the exact contribution of extracellular beta-amyloid on neurons remains incompletely comprehended. In our experiments, we studied the effect of β-amyloid peptide (Aβ1-42) on the action potential (APs) generation in isolated CA1 hippocampal neurons in perforated patch clamp conditions. Our findings demonstrate that Aβ1-42 affects the generation of APs differently in various hippocampal neurons, albeit with a shared effect of enhancing the firing response of the neurons within a minute of the start of Aβ1-42 application. In the first response type, there was a shift of 20-65% toward smaller values in the firing threshold of action potentials in response to inward current. Conversely, the firing threshold of action potentials was not affected in the second type of response to the application of Aβ1-42. In these neurons, Aβ1-42 caused a moderate increase in the frequency of spiking, up to 15%, with a relatively uniform increase in the frequency of action potentials generation regardless of the level of input current. Obtained data prove the absence of direct short-term negative effect of the Aβ1-42 on APs generation in neurons. Even with increasing the APs generation frequency and lowering the neurons' activation threshold, neurons were functional. Obtained data can suggest that only the long-acting presence of the Aβ1-42 in the cell environment can cause neuronal dysfunction due to a prolonged increase of APs firing and predisposition to this process.
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13
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Human antimicrobial peptide LL-37 contributes to Alzheimer's disease progression. Mol Psychiatry 2022; 27:4790-4799. [PMID: 36138130 DOI: 10.1038/s41380-022-01790-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/02/2022] [Accepted: 09/09/2022] [Indexed: 12/29/2022]
Abstract
As a prime mover in Alzheimer's disease (AD), microglial activation requires membrane translocation, integration, and activation of the metamorphic protein chloride intracellular channel 1 (CLIC1), which is primarily cytoplasmic under physiological conditions. However, the formation and activation mechanisms of functional CLIC1 are unknown. Here, we found that the human antimicrobial peptide (AMP) LL-37 promoted CLIC1 membrane translocation and integration. It also activates CLIC1 to cause microglial hyperactivation, neuroinflammation, and excitotoxicity. In mouse and monkey models, LL-37 caused significant pathological phenotypes linked to AD, including elevated amyloid-β, increased neurofibrillary tangles, enhanced neuronal death and brain atrophy, enlargement of lateral ventricles, and impairment of synaptic plasticity and cognition, while Clic1 knockout and blockade of LL-37-CLIC1 interactions inhibited these phenotypes. Given AD's association with infection and that overloading AMP may exacerbate AD, this study suggests that LL-37, which is up-regulated upon infection, may be a driving force behind AD by acting as an endogenous agonist of CLIC1.
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14
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Piccialli I, Sisalli MJ, de Rosa V, Boscia F, Tedeschi V, Secondo A, Pannaccione A. Increased K V2.1 Channel Clustering Underlies the Reduction of Delayed Rectifier K + Currents in Hippocampal Neurons of the Tg2576 Alzheimer's Disease Mouse. Cells 2022; 11:cells11182820. [PMID: 36139395 PMCID: PMC9497218 DOI: 10.3390/cells11182820] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/01/2022] [Accepted: 09/07/2022] [Indexed: 11/30/2022] Open
Abstract
Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the progressive deterioration of cognitive functions. Cortical and hippocampal hyperexcitability intervenes in the pathological derangement of brain activity leading to cognitive decline. As key regulators of neuronal excitability, the voltage-gated K+ channels (KV) might play a crucial role in the AD pathophysiology. Among them, the KV2.1 channel, the main α subunit mediating the delayed rectifier K+ currents (IDR) and controlling the intrinsic excitability of pyramidal neurons, has been poorly examined in AD. In the present study, we investigated the KV2.1 protein expression and activity in hippocampal neurons from the Tg2576 mouse, a widely used transgenic model of AD. To this aim we performed whole-cell patch-clamp recordings, Western blotting, and immunofluorescence analyses. Our Western blotting results reveal that KV2.1 was overexpressed in the hippocampus of 3-month-old Tg2576 mice and in primary hippocampal neurons from Tg2576 mouse embryos compared with the WT counterparts. Electrophysiological experiments unveiled that the whole IDR were reduced in the Tg2576 primary neurons compared with the WT neurons, and that this reduction was due to the loss of the KV2.1 current component. Moreover, we found that the reduction of the KV2.1-mediated currents was due to increased channel clustering, and that glutamate, a stimulus inducing KV2.1 declustering, was able to restore the IDR to levels comparable to those of the WT neurons. These findings add new information about the dysregulation of ionic homeostasis in the Tg2576 AD mouse model and identify KV2.1 as a possible player in the AD-related alterations of neuronal excitability.
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15
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Ohline SM, Liu X, Ibrahim MF, Mockett BM, Empson RM, Abraham WC, Iremonger KJ, Jones PP. Altered membrane properties but unchanged intrinsic excitability and spontaneous postsynaptic currents in an aged APPswe/PS1dE9 model of Alzheimer’s disease. Front Cell Neurosci 2022; 16:958876. [PMID: 36090787 PMCID: PMC9459330 DOI: 10.3389/fncel.2022.958876] [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: 06/01/2022] [Accepted: 08/09/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal hyperexcitability in Alzheimer’s disease (AD) models is thought to either contribute to the formation of amyloid beta plaques or result from their formation. Neuronal hyperexcitability has been shown in the cerebral cortex of the widely used young APPswe/PS1dE9 mice, which have accelerated plaque formation. However, it is currently unclear if hyperexcitability also occurs in CA1 hippocampal neurons of aged animals in this model. In the present work, we have compared intrinsic excitability and spontaneous synaptic inputs from CA1 pyramidal cells of 8-month-old APPswe/PS1dE9 and wildtype control mice. We find no change in intrinsic excitability or spontaneous postsynaptic currents (PSCs) between groups. We did, however, find a reduced input resistance and an increase in hyperpolarization-activated sag current. These results are consistent with findings from other aged AD model mice, including the widely used 5xFAD and 3xTg. Together these results suggest that neuronal hyperexcitability is not a consistent feature of all AD mouse models, particularly at advanced ages.
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Affiliation(s)
- Shane M. Ohline
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- HeartOtago, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- *Correspondence: Shane M. Ohline,
| | - Xinhuai Liu
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Mohamed F. Ibrahim
- Nuffield Department of Clinical Neurosciences, Oxford University, Oxford, United Kingdom
| | - Bruce M. Mockett
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Ruth M. Empson
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Wickliffe C. Abraham
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Department of Psychology, University of Otago, Dunedin, New Zealand
| | - Karl J. Iremonger
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
| | - Peter P. Jones
- Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- HeartOtago, University of Otago, Dunedin, New Zealand
- Brain Health Research Centre, University of Otago, Dunedin, New Zealand
- Peter P. Jones,
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16
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Amyloid Beta Alters Prefrontal-dependent Functions Along with its Excitability and Synaptic Plasticity in Male Rats. Neuroscience 2022; 498:260-279. [PMID: 35839923 DOI: 10.1016/j.neuroscience.2022.07.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 06/20/2022] [Accepted: 07/07/2022] [Indexed: 12/17/2022]
Abstract
Prefrontal cortex (PFC)-related functions, such as working memory (WM) and cognitive flexibility (CF), are among the first to be altered at early stages of Alzheimer's disease (AD). Likewise, transgenic AD models carrying different AD-related mutations, mostly linked to the overproduction of amyloid beta (Aβ) and other peptides, show premature behavioral and functional symptoms associated with PFC alterations. However, little is known about the effects of intracerebral or intra-PFC Aβ infusion on WM and CF, as well as on pyramidal cell excitability and plasticity. Thus, here we evaluated the effects of a single Aβ injection, directly into the PFC, or its intracerebroventricular (icv) application, on PFC-dependent behaviors and on the intrinsic and synaptic properties of layer V pyramidal neurons in PFC slices. We found that a single icv Aβ infusion reduced learning and performance of a delayed non-matching-to-sample WM task and prevented reversal learning in a matching-to-sample version of the task, several weeks after its infusion. The inhibition of WM performance was reproduced more potently by a single PFC Aβ infusion and was associated with Aβ accumulation. This behavioral disruption was related to increased layer V pyramidal cell firing, larger sag membrane potential, increased fast after-hyperpolarization and a failure to sustain synaptic long-term potentiation, even leading to long-term depression, at both the hippocampal-PFC pathway and intracortical synapses. These findings show that Aβ can affect PFC excitability and synaptic plasticity balance, damaging PFC-dependent functions, which could constitute the foundations of the early alterations in executive functions in AD patients.
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17
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Khonacha SE, Mirbehbahani SH, Rahdar M, Davoudi S, Borjkhani M, Khodaghli F, Motamedi F, Janahmadia M. Kisspeptin-13 prevented the electrophysiological alterations induced by Amyloid-Beta pathology in rat: Possible involvement of stromal interaction molecules and pCREB. Brain Res Bull 2022; 184:13-23. [PMID: 35272006 DOI: 10.1016/j.brainresbull.2022.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/25/2022] [Accepted: 03/04/2022] [Indexed: 11/24/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurological disease that slowly causing memory impairments with no effective treatment. We have recently reported that kisspeptin-13 (KP-13) ameliorates Aβ toxicity-induced memory deficit in rats. Here, the possible cellular impact of kisspeptin receptor activation in a rat model of the early stage AD was assessed using whole-cell patch-clamp recording from CA1 pyramidal neurons and molecular approaches. Compared to neurons from the control group, cells from the Aβ-treated group displayed spontaneous and evoked hyperexcitability with lower spike frequency adaptation. These cells had also a lower sag ratio in response to hyperpolarizing prepulse current delivered before a depolarizing current injection. Neurons from the Aβ-treated group exhibited short spike onset latency, lower rheobase and short utilization time compared with those in the control group. Furthermore, phase plot analysis of action potential showed that Aβ treatment affected the action potential features. These electrophysiological changes induced by Aβ were associated with increased expression of stromal interaction molecules (STIMs), particularly (STIM2) and decreased pCREB/CREB ratio. Treatment with KP-13 following Aβ injection into the entorhinal cortex, however, prevented the excitatory effect of Aβ on spontaneous and evoked neuronal activity, increased the latency of onset, enhanced the sag ratio, increased the rheobase and utilization time, and prevented the changes induced Aβ on spike parameters. In addition, the KP-13 application after Aβ treatment reduced the expression of STIMs and increased the pCREB/CREB ratio compared to those receiving Aβ treatment alone. In summary, these results provide evidence that activation of kisspeptin receptor may be effective against pathology of Aβ.
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Affiliation(s)
- Shima Ebrahimi Khonacha
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Mona Rahdar
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shima Davoudi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mehdi Borjkhani
- Department of Electrical Engineering, Urmia University of Technology, Urmia, Iran
| | - Fariba Khodaghli
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereshteh Motamedi
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahyar Janahmadia
- Neuroscience Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran; Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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18
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Prista von Bonhorst F, Gall D, Dupont G. Impact of β-Amyloids Induced Disruption of Ca2+ Homeostasis in a Simple Model of Neuronal Activity. Cells 2022; 11:cells11040615. [PMID: 35203266 PMCID: PMC8869902 DOI: 10.3390/cells11040615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 01/31/2022] [Accepted: 02/01/2022] [Indexed: 01/25/2023] Open
Abstract
Alzheimer’s disease is characterized by a marked dysregulation of intracellular Ca2+ homeostasis. In particular, toxic β-amyloids (Aβ) perturb the activities of numerous Ca2+ transporters or channels. Because of the tight coupling between Ca2+ dynamics and the membrane electrical activity, such perturbations are also expected to affect neuronal excitability. We used mathematical modeling to systematically investigate the effects of changing the activities of the various targets of Aβ peptides reported in the literature on calcium dynamics and neuronal excitability. We found that the evolution of Ca2+ concentration just below the plasma membrane is regulated by the exchanges with the extracellular medium, and is practically independent from the Ca2+ exchanges with the endoplasmic reticulum. Thus, disruptions of Ca2+ homeostasis interfering with signaling do not affect the electrical properties of the neurons at the single cell level. In contrast, the model predicts that by affecting the activities of L-type Ca2+ channels or Ca2+-activated K+ channels, Aβ peptides promote neuronal hyperexcitability. On the contrary, they induce hypo-excitability when acting on the plasma membrane Ca2+ ATPases. Finally, the presence of pores of amyloids in the plasma membrane can induce hypo- or hyperexcitability, depending on the conditions. These modeling conclusions should help with analyzing experimental observations in which Aβ peptides interfere at several levels with Ca2+ signaling and neuronal activity.
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Affiliation(s)
- Francisco Prista von Bonhorst
- Unit of Theoretical Chronobiology, Faculté des Sciences (CP231), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium;
| | - David Gall
- Research Laboratory in Human Reproduction, Faculté de Médecine (CP636), Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium;
| | - Geneviève Dupont
- Unit of Theoretical Chronobiology, Faculté des Sciences (CP231), Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium;
- Correspondence:
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Olajide OJ, Chapman CA. Amyloid-β (1-42) peptide induces rapid NMDA receptor-dependent alterations at glutamatergic synapses in the entorhinal cortex. Neurobiol Aging 2021; 105:296-309. [PMID: 34144329 DOI: 10.1016/j.neurobiolaging.2021.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 04/26/2021] [Accepted: 05/11/2021] [Indexed: 12/29/2022]
Abstract
The hippocampus and entorhinal cortex (EC) accumulate amyloid beta peptides (Aβ) that promote neuropathology in Alzheimer's disease, but the early effects of Aβ on excitatory synaptic transmission in the EC have not been well characterized. To assess the acute effects of Aβ1-42 on glutamatergic synapses, acute brain slices from wildtype rats were exposed to Aβ1-42 or control solution for 3 hours, and tissue was analyzed using protein immunoblotting and quantitative PCR. Presynaptically, Aβ1-42 induced marked reductions in synaptophysin, synapsin-2a mRNA, and mGluR3 mRNA, and increased both VGluT2 protein and Ca2+-activated channel KCa2.2 mRNA levels. Postsynaptically, Aβ1-42 reduced PSD95 and GluN2B protein, and also downregulated GluN2B and GluN2A mRNA, without affecting scaffolding elements SAP97 and PICK1. mGluR5 mRNA was strongly increased, while mGluR1 mRNA was unaffected. Blocking either GluN2A- or GluN2B-containing NMDA receptors did not significantly prevent synaptic changes induced by Aβ1-42, but combined blockade did prevent synaptic alterations. These findings demonstrate that Aβ1-42 rapidly disrupts glutamatergic transmission in the EC through mechanisms involving concurrent activation of GluN2A- and GluN2B-containing NMDA receptors.
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Affiliation(s)
- Olayemi Joseph Olajide
- Division of Neurobiology, Department of Anatomy, University of Ilorin, Ilorin, Nigeria; Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada
| | - Clifton Andrew Chapman
- Center for Studies in Behavioral Neurobiology, Department of Psychology, Concordia University, Montréal, Québec, Canada.
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Tok S, Ahnaou A, Drinkenburg W. Functional Neurophysiological Biomarkers of Early-Stage Alzheimer's Disease: A Perspective of Network Hyperexcitability in Disease Progression. J Alzheimers Dis 2021; 88:809-836. [PMID: 34420957 PMCID: PMC9484128 DOI: 10.3233/jad-210397] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Network hyperexcitability (NH) has recently been suggested as a potential neurophysiological indicator of Alzheimer’s disease (AD), as new, more accurate biomarkers of AD are sought. NH has generated interest as a potential indicator of certain stages in the disease trajectory and even as a disease mechanism by which network dysfunction could be modulated. NH has been demonstrated in several animal models of AD pathology and multiple lines of evidence point to the existence of NH in patients with AD, strongly supporting the physiological and clinical relevance of this readout. Several hypotheses have been put forward to explain the prevalence of NH in animal models through neurophysiological, biochemical, and imaging techniques. However, some of these hypotheses have been built on animal models with limitations and caveats that may have derived NH through other mechanisms or mechanisms without translational validity to sporadic AD patients, potentially leading to an erroneous conclusion of the underlying cause of NH occurring in patients with AD. In this review, we discuss the substantiation for NH in animal models of AD pathology and in human patients, as well as some of the hypotheses considering recently developed animal models that challenge existing hypotheses and mechanisms of NH. In addition, we provide a preclinical perspective on how the development of animal models incorporating AD-specific NH could provide physiologically relevant translational experimental data that may potentially aid the discovery and development of novel therapies for AD.
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Affiliation(s)
- Sean Tok
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium.,Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, The Netherlands
| | - Abdallah Ahnaou
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium
| | - Wilhelmus Drinkenburg
- Department of Neuroscience, Janssen Research & Development, Janssen Pharmaceutica NV, Beerse, Belgium.,Groningen Institute for Evolutionary Life Sciences, Faculty of Science and Engineering, University of Groningen, The Netherlands
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Chen WB, Wang YX, Wang HG, An D, Sun D, Li P, Zhang T, Lu WG, Liu YQ. TPEN attenuates amyloid-β 25-35-induced neuronal damage with changes in the electrophysiological properties of voltage-gated sodium and potassium channels. Mol Brain 2021; 14:124. [PMID: 34384467 PMCID: PMC8359616 DOI: 10.1186/s13041-021-00837-z] [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: 05/05/2021] [Accepted: 08/02/2021] [Indexed: 11/10/2022] Open
Abstract
To understand the role of intracellular zinc ion (Zn2+) dysregulation in mediating age-related neurodegenerative changes, particularly neurotoxicity resulting from the generation of excessive neurotoxic amyloid-β (Aβ) peptides, this study aimed to investigate whether N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), a Zn2+-specific chelator, could attenuate Aβ25-35-induced neurotoxicity and the underlying electrophysiological mechanism. We used the 3-(4, 5-dimethyl-thiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay to measure the viability of hippocampal neurons and performed single-cell confocal imaging to detect the concentration of Zn2+ in these neurons. Furthermore, we used the whole-cell patch-clamp technique to detect the evoked repetitive action potential (APs), the voltage-gated sodium and potassium (K+) channels of primary hippocampal neurons. The analysis showed that TPEN attenuated Aβ25-35-induced neuronal death, reversed the Aβ25-35-induced increase in intracellular Zn2+ concentration and the frequency of APs, inhibited the increase in the maximum current density of voltage-activated sodium channel currents induced by Aβ25-35, relieved the Aβ25-35-induced decrease in the peak amplitude of transient outward K+ currents (IA) and outward-delayed rectifier K+ currents (IDR) at different membrane potentials, and suppressed the steady-state activation and inactivation curves of IA shifted toward the hyperpolarization direction caused by Aβ25-35. These results suggest that Aβ25-35-induced neuronal damage correlated with Zn2+ dysregulation mediated the electrophysiological changes in the voltage-gated sodium and K+ channels. Moreover, Zn2+-specific chelator-TPEN attenuated Aβ25-35-induced neuronal damage by recovering the intracellular Zn2+ concentration.
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Affiliation(s)
- Wen-Bo Chen
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yu-Xiang Wang
- Department of Immunology and Pathogenic Biology, School of Basic Medical Sciences, Hebei University of Chinese Medicine, Shijiazhuang, 050200, Hebei, People's Republic of China
| | - Hong-Gang Wang
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Di An
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Dan Sun
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Pan Li
- Tianjin Key Laboratory of Cerebral Vascular and Neurodegenerative Diseases, Tianjin Neurosurgery Institute, Department of Neurology, Tianjin Huanhu Hospital Affiliated to Nankai University, Tianjin, People's Republic of China
| | - Tao Zhang
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Wan-Ge Lu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China
| | - Yan-Qiang Liu
- College of Life Sciences, Nankai University, Tianjin, 300071, People's Republic of China.
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22
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Bettegazzi B, Sebastian Monasor L, Bellani S, Codazzi F, Restelli LM, Colombo AV, Deigendesch N, Frank S, Saito T, Saido TC, Lammich S, Tahirovic S, Grohovaz F, Zacchetti D. Casein Kinase 2 dependent phosphorylation of eIF4B regulates BACE1 expression in Alzheimer's disease. Cell Death Dis 2021; 12:769. [PMID: 34349120 PMCID: PMC8339060 DOI: 10.1038/s41419-021-04062-3] [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: 03/19/2021] [Revised: 07/07/2021] [Accepted: 07/12/2021] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder. Increased Aβ production plays a fundamental role in the pathogenesis of the disease and BACE1, the protease that triggers the amyloidogenic processing of APP, is a key protein and a pharmacological target in AD. Changes in neuronal activity have been linked to BACE1 expression and Aβ generation, but the underlying mechanisms are still unclear. We provide clear evidence for the role of Casein Kinase 2 in the control of activity-driven BACE1 expression in cultured primary neurons, organotypic brain slices, and murine AD models. More specifically, we demonstrate that neuronal activity promotes Casein Kinase 2 dependent phosphorylation of the translation initiation factor eIF4B and this, in turn, controls BACE1 expression and APP processing. Finally, we show that eIF4B expression and phosphorylation are increased in the brain of APPPS1 and APP-KI mice, as well as in AD patients. Overall, we provide a definition of a mechanism linking brain activity with amyloid production and deposition, opening new perspectives from the therapeutic standpoint.
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Affiliation(s)
- Barbara Bettegazzi
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy.
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
| | | | - Serena Bellani
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Franca Codazzi
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Lisa Michelle Restelli
- Basel University Hospital, Institute of Medical Genetics and Pathology, Schoenbeinstrasse 40, 4031, Basel (CH), Switzerland
| | | | - Nikolaus Deigendesch
- Basel University Hospital, Institute of Medical Genetics and Pathology, Schoenbeinstrasse 40, 4031, Basel (CH), Switzerland
| | - Stephan Frank
- Basel University Hospital, Institute of Medical Genetics and Pathology, Schoenbeinstrasse 40, 4031, Basel (CH), Switzerland
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science Institute, Wako, Saitama, 351-0198, Japan
- Department of Neurocognitive Science, Nagoya City University Graduate School of Medical Science, Nagoya, Aichi, 467-8601, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science Institute, Wako, Saitama, 351-0198, Japan
| | - Sven Lammich
- BMC - Biochemistry, Ludwig Maximilians University Munich, 81377, Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE) Munich, 81377, Munich, Germany
| | - Fabio Grohovaz
- Vita-Salute San Raffaele University, via Olgettina 58, 20132, Milan, Italy
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy
| | - Daniele Zacchetti
- IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132, Milan, Italy.
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Back MK, Ruggieri S, Jacobi E, von Engelhardt J. Amyloid Beta-Mediated Changes in Synaptic Function and Spine Number of Neocortical Neurons Depend on NMDA Receptors. Int J Mol Sci 2021; 22:ijms22126298. [PMID: 34208315 PMCID: PMC8231237 DOI: 10.3390/ijms22126298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/07/2021] [Accepted: 06/09/2021] [Indexed: 11/16/2022] Open
Abstract
Onset and progression of Alzheimer's disease (AD) pathophysiology differs between brain regions. The neocortex, for example, is a brain region that is affected very early during AD. NMDA receptors (NMDARs) are involved in mediating amyloid beta (Aβ) toxicity. NMDAR expression, on the other hand, can be affected by Aβ. We tested whether the high vulnerability of neocortical neurons for Aβ-toxicity may result from specific NMDAR expression profiles or from a particular regulation of NMDAR expression by Aβ. Electrophysiological analyses suggested that pyramidal cells of 6-months-old wildtype mice express mostly GluN1/GluN2A NMDARs. While synaptic NMDAR-mediated currents are unaltered in 5xFAD mice, extrasynaptic NMDARs seem to contain GluN1/GluN2A and GluN1/GluN2A/GluN2B. We used conditional GluN1 and GluN2B knockout mice to investigate whether NMDARs contribute to Aβ-toxicity. Spine number was decreased in pyramidal cells of 5xFAD mice and increased in neurons with 3-week virus-mediated Aβ-overexpression. NMDARs were required for both Aβ-mediated changes in spine number and functional synapses. Thus, our study gives novel insights into the Aβ-mediated regulation of NMDAR expression and the role of NMDARs in Aβ pathophysiology in the somatosensory cortex.
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Alcantara-Gonzalez D, Chartampila E, Criscuolo C, Scharfman HE. Early changes in synaptic and intrinsic properties of dentate gyrus granule cells in a mouse model of Alzheimer's disease neuropathology and atypical effects of the cholinergic antagonist atropine. Neurobiol Dis 2021; 152:105274. [PMID: 33484828 DOI: 10.1016/j.nbd.2021.105274] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 01/09/2021] [Accepted: 01/16/2021] [Indexed: 12/19/2022] Open
Abstract
It has been reported that hyperexcitability occurs in a subset of patients with Alzheimer's disease (AD) and hyperexcitability could contribute to the disease. Several studies have suggested that the hippocampal dentate gyrus (DG) may be an important area where hyperexcitability occurs. Therefore, we tested the hypothesis that the principal DG cell type, granule cells (GCs), would exhibit changes at the single-cell level which would be consistent with hyperexcitability and might help explain it. We used the Tg2576 mouse, where it has been shown that hyperexcitability is robust at 2-3 months of age. GCs from 2 to 3-month-old Tg2576 mice were compared to age-matched wild type (WT) mice. Effects of muscarinic cholinergic antagonism were tested because previously we found that Tg2576 mice exhibited hyperexcitability in vivo that was reduced by the muscarinic cholinergic antagonist atropine, counter to the dogma that in AD one needs to boost cholinergic function. The results showed that GCs from Tg2576 mice exhibited increased frequency of spontaneous excitatory postsynaptic potentials/currents (sEPSP/Cs) and reduced frequency of spontaneous inhibitory synaptic events (sIPSCs) relative to WT, increasing the excitation:inhibition (E:I) ratio. There was an inward NMDA receptor-dependent current that we defined here as a novel synaptic current (nsC) in Tg2576 mice because it was very weak in WT mice. Intrinsic properties were distinct in Tg2576 GCs relative to WT. In summary, GCs of the Tg2576 mouse exhibit early electrophysiological alterations that are consistent with increased synaptic excitation, reduced inhibition, and muscarinic cholinergic dysregulation. The data support previous suggestions that the DG contributes to hyperexcitability and there is cholinergic dysfunction early in life in AD mouse models.
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Affiliation(s)
- David Alcantara-Gonzalez
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Elissavet Chartampila
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Chiara Criscuolo
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA.
| | - Helen E Scharfman
- Center for Dementia Research, the Nathan Kline Institute for Psychiatric Research, Orangeburg, NY 10962, USA; Department of Child & Adolescent Psychiatry, Neuroscience & Physiology, and Psychiatry, New York University Langone Health, New York, NY 10016, USA; Neuroscience Institute, New York University Langone Health, New York, NY 10016, USA.
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25
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Mayordomo-Cava J, Iborra-Lázaro G, Djebari S, Temprano-Carazo S, Sánchez-Rodríguez I, Jeremic D, Gruart A, Delgado-García JM, Jiménez-Díaz L, Navarro-López JD. Impairments of Synaptic Plasticity Induction Threshold and Network Oscillatory Activity in the Hippocampus Underlie Memory Deficits in a Non-Transgenic Mouse Model of Amyloidosis. BIOLOGY 2020; 9:biology9070175. [PMID: 32698467 PMCID: PMC7407959 DOI: 10.3390/biology9070175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/07/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022]
Abstract
In early Alzheimer disease (AD) models synaptic failures and upstreaming aberrant patterns of network synchronous activity result in hippocampal-dependent memory deficits. In such initial stage, soluble forms of Amyloid-β (Aβ) peptides have been shown to play a causal role. Among different Aβ species, Aβ25-35 has been identified as the biologically active fragment, as induces major neuropathological signs related to early AD stages. Consequently, it has been extensively used to acutely explore the pathophysiological events related with neuronal dysfunction induced by soluble Aβ forms. However, the synaptic mechanisms underlying its toxic effects on hippocampal-dependent memory remain unresolved. Here, in an in vivo model of amyloidosis generated by intracerebroventricular injections of Aβ25-35 we studied the synaptic dysfunction mechanisms underlying hippocampal cognitive deficits. At the synaptic level, long-term potentiation (LTP) of synaptic excitation and inhibition was induced in CA1 region by high frequency simulation (HFS) applied to Schaffer collaterals. Aβ25-35 was found to alter metaplastic mechanisms of plasticity, facilitating long-term depression (LTD) of both types of LTP. In addition, aberrant synchronization of hippocampal network activity was found while at the behavioral level, deficits in hippocampal-dependent habituation and recognition memories emerged. Together, our results provide a substrate for synaptic disruption mechanism underlying hippocampal cognitive deficits present in Aβ25-35 amyloidosis model.
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Affiliation(s)
- Jennifer Mayordomo-Cava
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Guillermo Iborra-Lázaro
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Souhail Djebari
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Sara Temprano-Carazo
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Irene Sánchez-Rodríguez
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Danko Jeremic
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, 41013 Seville, Spain; (A.G.); (J.M.D.-G.)
| | | | - Lydia Jiménez-Díaz
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
- Correspondence: (L.J.-D.); (J.D.N.-L.)
| | - Juan D. Navarro-López
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
- Correspondence: (L.J.-D.); (J.D.N.-L.)
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26
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Epilepsy and Alzheimer’s Disease: Potential mechanisms for an association. Brain Res Bull 2020; 160:107-120. [DOI: 10.1016/j.brainresbull.2020.04.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/05/2020] [Accepted: 04/10/2020] [Indexed: 12/16/2022]
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Hippocampal synaptic and membrane function in the DBA/2J-mdx mouse model of Duchenne muscular dystrophy. Mol Cell Neurosci 2020; 104:103482. [PMID: 32171922 DOI: 10.1016/j.mcn.2020.103482] [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: 10/04/2019] [Revised: 03/09/2020] [Accepted: 03/10/2020] [Indexed: 12/14/2022] Open
Abstract
Dystrophin deficiency is associated with alterations in cell physiology. The functional consequences of dystrophin deficiency are particularly severe for muscle physiology, as observed in Duchenne muscle dystrophy (DMD). DMD is caused by the absence of a 427 kDa isoform of dystrophin. However, in addition to muscular dystrophy symptoms, DMD is frequently associated with memory and attention deficits and epilepsy. While this may be associated with a role for dystrophin in neuronal physiology, it is not clear what neuronal alterations are linked with DMD. Our work shows that CA1 pyramidal neurons from DBA/2J-mdx mice have increased afterhyperpolarization compared to WT controls. All the other electrotonic and electrogenic membrane properties were unaffected by this genotype. Finally, basal synaptic transmission, short-term and long-term synaptic plasticity at Schaffer collateral to CA1 glutamatergic synapses were unchanged between mdx and WT controls. These data show that the excitatory component of hippocampal activity is largely preserved in DBA/2J-mdx mice. Further studies, extending the investigation to the inhibitory GABAergic function, may provide a more complete picture of the functional, network alterations underlying impaired cognition in DMD. In addition, the investigation of changes in neuronal single conductance biophysical properties associated with this genotype, is required to identify the functional alterations associated with dystrophin deficiency and clarify its role in neuronal function.
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Piras IS, Bleul C, Talboom JS, De Both MD, Schrauwen I, Halliday G, Myers AJ, Serrano GE, Beach TG, Huentelman MJ. ESHRD: deconvolution of brain homogenate RNA expression data to identify cell-type-specific alterations in Alzheimer's disease. Aging (Albany NY) 2020; 12:4124-4162. [PMID: 32125278 PMCID: PMC7093163 DOI: 10.18632/aging.102840] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 02/04/2020] [Indexed: 12/12/2022]
Abstract
Objective: We describe herein a bioinformatics approach that leverages gene expression data from brain homogenates to derive cell-type specific differential expression results. Results: We found that differentially expressed (DE) cell-specific genes were mostly identified as neuronal, microglial, or endothelial in origin. However, a large proportion (75.7%) was not attributable to specific cells due to the heterogeneity in expression among brain cell types. Neuronal DE genes were consistently downregulated and associated with synaptic and neuronal processes as described previously in the field thereby validating this approach. We detected several DE genes related to angiogenesis (endothelial cells) and proteoglycans (oligodendrocytes). Conclusions: We present a cost- and time-effective method exploiting brain homogenate DE data to obtain insights about cell-specific expression. Using this approach we identify novel findings in AD in endothelial cells and oligodendrocytes that were previously not reported. Methods: We derived an enrichment score for each gene using a publicly available RNA profiling database generated from seven different cell types isolated from mouse cerebral cortex. We then classified the differential expression results from 3 publicly accessible Late-Onset Alzheimer’s disease (AD) studies including seven different brain regions.
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Affiliation(s)
- Ignazio S Piras
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Christiane Bleul
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Joshua S Talboom
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Matthew D De Both
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA
| | - Isabelle Schrauwen
- Center for Statistical Genetics, Department of Neurology, Gertrude H. Sergievsky Center, Columbia University Medical Center, New York, NY 10032, USA
| | - Glenda Halliday
- The University of Sydney School of Medicine, Sydney, Camperdown NSW 2050, Australia
| | | | - Geidy E Serrano
- Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Thomas G Beach
- Banner Sun Health Research Institute, Sun City, AZ 85351, USA
| | - Matthew J Huentelman
- Neurogenomics Division, The Translational Genomics Research Institute, Phoenix, AZ 85004, USA
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Angulo SL, Henzi T, Neymotin SA, Suarez MD, Lytton WW, Schwaller B, Moreno H. Amyloid pathology-produced unexpected modifications of calcium homeostasis in hippocampal subicular dendrites. Alzheimers Dement 2020; 16:251-261. [PMID: 31668966 DOI: 10.1016/j.jalz.2019.07.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Alzheimer's disease (AD) is linked to neuronal calcium dyshomeostasis, which is associated with network hyperexcitability. Decreased expression of the calcium-binding protein cal- bindin-D28K (CB) might be a susceptibility factor for AD. The subiculum is affected early in AD, for unknown reasons. METHODS In AD, CB knock-out and control mice fluorescence Ca2+ imaging combined with patch clamp were used to characterize Ca2+ dynamics, resting Ca2+ , and Ca2+ -buffering capacity in subicular neurons. CB expression levels in wild-type and AD mice were also analyzed. RESULTS The subiculum and dentate gyrus of wild-type mice showed age-related decline in CB expression not observed in AD mice. Resting Ca2+ and Ca2+ -buffering capacity was increased in aged AD mice subicular dendrites. Modeling suggests that AD calcium changes can be explained by alterations of Ca2+ extrusion pumps rather than by buffers. DISCUSSION Overall, abnormal Ca2+ homeostasis in AD has an age dependency that comprises multiple mechanisms, including compensatory processes.
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Affiliation(s)
- Sergio L Angulo
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Thomas Henzi
- Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Samuel A Neymotin
- Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, USA
| | - Manuel D Suarez
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - William W Lytton
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Kings County Hospital, Brooklyn, NY, USA
| | - Beat Schwaller
- Anatomy, Department of Medicine, University of Fribourg, Fribourg, Switzerland
| | - Herman Moreno
- Departments of Neurology and Physiology/Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, Brooklyn, NY, USA
- Kings County Hospital, Brooklyn, NY, USA
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30
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Sánchez-Rodríguez I, Djebari S, Temprano-Carazo S, Vega-Avelaira D, Jiménez-Herrera R, Iborra-Lázaro G, Yajeya J, Jiménez-Díaz L, Navarro-López JD. Hippocampal long-term synaptic depression and memory deficits induced in early amyloidopathy are prevented by enhancing G-protein-gated inwardly rectifying potassium channel activity. J Neurochem 2020; 153:362-376. [PMID: 31875959 PMCID: PMC7217154 DOI: 10.1111/jnc.14946] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 12/06/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022]
Abstract
Hippocampal synaptic plasticity disruption by amyloid‐β (Aβ) peptides + thought to be responsible for learning and memory impairments in Alzheimer's disease (AD) early stage. Failures in neuronal excitability maintenance seems to be an underlying mechanism. G‐protein‐gated inwardly rectifying potassium (GirK) channels control neural excitability by hyperpolarization in response to many G‐protein‐coupled receptors activation. Here, in early in vitro and in vivo amyloidosis mouse models, we study whether GirK channels take part of the hippocampal synaptic plasticity impairments generated by Aβ1–42. In vitro electrophysiological recordings from slices showed that Aβ1–42 alters synaptic plasticity by switching high‐frequency stimulation (HFS) induced long‐term potentiation (LTP) to long‐term depression (LTD), which led to in vivo hippocampal‐dependent memory deficits. Remarkably, selective pharmacological activation of GirK channels with ML297 rescued both HFS‐induced LTP and habituation memory from Aβ1–42 action. Moreover, when GirK channels were specifically blocked by Tertiapin‐Q, their activation with ML297 failed to rescue LTP from the HFS‐dependent LTD induced by Aβ1–42. On the other hand, the molecular analysis of the recorded slices by western blot showed that the expression of GIRK1/2 subunits, which form the prototypical GirK channel in the hippocampus, was not significantly regulated by Aβ1–42. However, immunohistochemical examination of our in vivo amyloidosis model showed Aβ1–42 to down‐regulate hippocampal GIRK1 subunit expression. Together, our results describe an Aβ‐mediated deleterious synaptic mechanism that modifies the induction threshold for hippocampal LTP/LTD and underlies memory alterations observed in amyloidosis models. In this scenario, GirK activation assures memory formation by preventing the transformation of HFS‐induced LTP into LTD. ![]()
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Affiliation(s)
- Irene Sánchez-Rodríguez
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Souhail Djebari
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Sara Temprano-Carazo
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - David Vega-Avelaira
- Departamento de Ciencias Biomédicas Básicas, European University of Madrid, Madrid, Spain
| | - Raquel Jiménez-Herrera
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Guillermo Iborra-Lázaro
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Javier Yajeya
- Instituto de Neurociencias de Castilla y León, University of Salamanca, Salamanca, Spain
| | - Lydia Jiménez-Díaz
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Juan D Navarro-López
- NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, Ciudad Real, Spain
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EGb 761 inhibits Aβ1-42-induced neuroinflammatory response by suppressing P38 MAPK signaling pathway in BV-2 microglial cells. Neuroreport 2019; 30:434-440. [PMID: 30817685 DOI: 10.1097/wnr.0000000000001223] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Ginkgo biloba extract EGb 761 possesses a variety of biological effects and has been proved to be beneficial in Alzheimer's disease. This study aimed to explore the anti-inflammatory mechanisms of EGb 761 on the Aβ1-42-induced BV-2 microglial cells. We analyzed the production and gene expression of proinflammatory cytokines by enzyme-linked immunosorbent assay and qRT-PCR, examined phosphorylation of MAPKs by western blot and measured nuclear factor-κB nuclear translocation. Compared with Aβ1-42-treated group, EGb 761 inhibited release and gene expression of tumor necrosis factor-α and interleukin-1β, suppressed nuclear translocation of nuclear factor-κB and attenuated phosphorylation of p38 MAPK in a concentration-dependent manner, but not ERK and JNK. In summary, the results suggested that EGb 761 could attenuate Aβ1-42-induced neuroinflammatory response.
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Amyloid β-Induced Upregulation of Na v1.6 Underlies Neuronal Hyperactivity in Tg2576 Alzheimer's Disease Mouse Model. Sci Rep 2019; 9:13592. [PMID: 31537873 PMCID: PMC6753212 DOI: 10.1038/s41598-019-50018-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 07/31/2019] [Indexed: 12/19/2022] Open
Abstract
Hyperexcitability and alterations in neuronal networks contribute to cognitive impairment in Alzheimer’s Disease (AD). Voltage-gated sodium channels (NaV), which are crucial for regulating neuronal excitability, have been implicated in AD-related hippocampal hyperactivity and higher incidence of spontaneous non-convulsive seizures. Here, we show by using primary hippocampal neurons exposed to amyloid-β1–42 (Aβ1–42) oligomers and from Tg2576 mouse embryos, that the selective upregulation of NaV1.6 subtype contributes to membrane depolarization and to the increase of spike frequency, thereby resulting in neuronal hyperexcitability. Interestingly, we also found that NaV1.6 overexpression is responsible for the aberrant neuronal activity observed in hippocampal slices from 3-month-old Tg2576 mice. These findings identify the NaV1.6 channels as a determinant of the hippocampal neuronal hyperexcitability induced by Aβ1–42 oligomers. The selective blockade of NaV1.6 overexpression and/or hyperactivity might therefore offer a new potential therapeutic approach to counteract early hippocampal hyperexcitability and subsequent cognitive deficits in the early stages of AD.
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Gavello D, Calorio C, Franchino C, Cesano F, Carabelli V, Carbone E, Marcantoni A. Early Alterations of Hippocampal Neuronal Firing Induced by Abeta42. Cereb Cortex 2019; 28:433-446. [PMID: 27999123 DOI: 10.1093/cercor/bhw377] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Indexed: 12/11/2022] Open
Abstract
We studied the effect of Amyloid β 1-42 oligomers (Abeta42) on Ca2+ dependent excitability profile of hippocampal neurons. Abeta42 is one of the Amyloid beta peptides produced by the proteolytic processing of the amyloid precursor protein and participates in the initiating event triggering the progressive dismantling of synapses and neuronal circuits. Our experiments on cultured hippocampal network reveal that Abeta42 increases intracellular Ca2+ concentration by 46% and inhibits firing discharge by 19%. More precisely, Abeta42 differently regulates ryanodine (RyRs), NMDA receptors (NMDARs), and voltage gated calcium channels (VGCCs) by increasing Ca2+ release through RyRs and inhibiting Ca2+ influx through NMDARs and VGCCs. The overall increased intracellular Ca2+ concentration causes stimulation of K+ current carried by big conductance Ca2+ activated potassium (BK) channels and hippocampal network firing inhibition. We conclude that Abeta42 alters neuronal function by means of at least 4 main targets: RyRs, NMDARs, VGCCs, and BK channels. The development of selective modulators of these channels may in turn be useful for developing effective therapies that could enhance the quality of life of AD patients during the early onset of the pathology.
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Affiliation(s)
- Daniela Gavello
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Chiara Calorio
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Claudio Franchino
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Federico Cesano
- Department of Chemistry Via Pietro Giuria 7, Torino University, 10125 Torino, Italy
| | - Valentina Carabelli
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Emilio Carbone
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
| | - Andrea Marcantoni
- Department of Drug Science and Technology, Torino University, Corso Raffaello 30, 10125 Torino, Italy
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Church TW, Brown JT, Marrion NV. β 3-Adrenergic receptor-dependent modulation of the medium afterhyperpolarization in rat hippocampal CA1 pyramidal neurons. J Neurophysiol 2019; 121:773-784. [PMID: 30625002 DOI: 10.1152/jn.00334.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Action potential firing in hippocampal pyramidal neurons is regulated by generation of an afterhyperpolarization (AHP). Three phases of AHP are recognized, with the fast AHP regulating action potential firing at the onset of a burst and the medium and slow AHPs supressing action potential firing over hundreds of milliseconds and seconds, respectively. Activation of β-adrenergic receptors suppresses the slow AHP by a protein kinase A-dependent pathway. However, little is known regarding modulation of the medium AHP. Application of the selective β-adrenergic receptor agonist isoproterenol suppressed both the medium and slow AHPs evoked in rat CA1 hippocampal pyramidal neurons recorded from slices maintained in organotypic culture. Suppression of the slow AHP was mimicked by intracellular application of cAMP, with the suppression of the medium AHP by isoproterenol still being evident in cAMP-dialyzed cells. Suppression of both the medium and slow AHPs was antagonized by the β-adrenergic receptor antagonist propranolol. The effect of isoproterenol to suppress the medium AHP was mimicked by two β3-adrenergic receptor agonists, BRL37344 and SR58611A. The medium AHP was mediated by activation of small-conductance calcium-activated K+ channels and deactivation of H channels at the resting membrane potential. Suppression of the medium AHP by isoproterenol was reduced by pretreating cells with the H-channel blocker ZD7288. These data suggest that activation of β3-adrenergic receptors inhibits H channels, which suppresses the medium AHP in CA1 hippocampal neurons by utilizing a pathway that is independent of a rise in intracellular cAMP. This finding highlights a potential new target in modulating H-channel activity and thereby neuronal excitability. NEW & NOTEWORTHY The noradrenergic input into the hippocampus is involved in modulating long-term synaptic plasticity and is implicated in learning and memory. We demonstrate that activation of functional β3-adrenergic receptors suppresses the medium afterhyperpolarization in hippocampal pyramidal neurons. This finding provides an additional mechanism to increase action potential firing frequency, where neuronal excitability is likely to be crucial in cognition and memory.
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Affiliation(s)
- Timothy W Church
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
| | - Jon T Brown
- University of Exeter Medical School , Exeter , United Kingdom
| | - Neil V Marrion
- School of Physiology, Pharmacology and Neuroscience, University of Bristol , Bristol , United Kingdom
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Binda A, Panariti A, Barbuti A, Murano C, Dal Magro R, Masserini M, Re F, Rivolta I. Modulation of the intrinsic neuronal excitability by multifunctional liposomes tailored for the treatment of Alzheimer's disease. Int J Nanomedicine 2018; 13:4059-4071. [PMID: 30034232 PMCID: PMC6047604 DOI: 10.2147/ijn.s161563] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Purpose Nanotechnologies turned out to be promising in the development of diagnostic and therapeutic approaches toward neurodegenerative disorders. However, only a very scant number of nanodevices until now proved to be effective on preclinical animal models. Although specific tests in vivo are available to assess the potential toxicity of these nanodevices on cognitive functions, those to evaluate their biosafety in vitro on neurons are still to be improved. Materials and methods We utilized the patch-clamp technique on primary cultures of cortical neural cells isolated from neonatal rats, aiming to evaluate their electrical properties after the incubation with liposomes (mApoE-PA-LIPs), previously proved able to cross the blood–brain barrier and to be effective on mouse models of Alzheimer’s disease (AD), both in the absence and in the presence of β-amyloid peptide oligomers. Results Data show a high degree of biocompatibility, evaluated by lactate dehydrogenase (LDH) release and MTT assay, and the lack of cellular internalization. After the incubation with mApoE-PA-LIPs, neuronal membranes show an increase in the input resistance (from 724.14±76 MΩ in untreated population to 886.06±86 MΩ in the treated one), a reduction in the rheobase current (from 29.6±3 to 24.2±3 pA in untreated and treated, respectively), and an increase of the firing frequency, consistent with an ultimate increase in intrinsic excitability. Data obtained after co-incubation of mApoE-PA-LIPs with β-amyloid peptide oligomers suggest a retention of liposome efficacy. Conclusion These data suggest the ability of liposomes to modulate neuronal electrical properties and are compatible with the previously demonstrated amelioration of cognitive functions induced by treatment of AD mice with liposomes. We conclude that this electrophysiological approach could represent a useful tool for nanomedicine to evaluate the effect of nanoparticles on intrinsic neuronal excitability.
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Affiliation(s)
- Anna Binda
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy,
| | - Alice Panariti
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy,
| | - Andrea Barbuti
- Department of Biosciences, The PaceLab and Interuniversity Center of Molecular Medicine and Applied Biophysics (CIMMBA), University of Milan, Milano, Italy
| | - Carmen Murano
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy,
| | - Roberta Dal Magro
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy,
| | - Massimo Masserini
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy, .,Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy, .,Nanomedicine Center NANOMIB, University of Milano-Bicocca, Milano, Italy,
| | - Francesca Re
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy, .,Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy, .,Nanomedicine Center NANOMIB, University of Milano-Bicocca, Milano, Italy,
| | - Ilaria Rivolta
- School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy, .,Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy, .,Nanomedicine Center NANOMIB, University of Milano-Bicocca, Milano, Italy,
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Abd El Wahab MG, Ali SS, Ayuob NN. The Role of Musk in Relieving the Neurodegenerative Changes Induced After Exposure to Chronic Stress. Am J Alzheimers Dis Other Demen 2018; 33:221-231. [PMID: 29385813 PMCID: PMC10852467 DOI: 10.1177/1533317518755993] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE This study aimed to evaluate the effect induced by musk on Alzheimer's disease-such as neurodegenerative changes in mice exposed to chronic unpredictable mild stress (CUMS). MATERIAL AND METHODS Forty male Swiss albino mice were divided into 4 groups (n = 10); control, CUMS, CUMS + fluoxetine, CUMS + musk. At the end of the experiment, behavior of the mice was assessed. Serum corticosterone level, hippocampal protein level of the glucocorticoid receptors, and brain-derived neurotropic factor were also assessed. Hippocampus was histopathologically examined. RESULTS Musk improved depressive status induced after exposure to CUMS as evidenced by the forced swimming and open field tests and improved the short-term memory as evidenced by the elevated plus maze test. Musk reduced both corticosterone levels and the hippocampal neurodegenerative changes observed after exposure to CUMS. These improvements were comparable to those induced by fluoxetine. CONCLUSION Musk alleviated the memory impairment and neurodegenerative changes induced after exposure to the chronic stress.
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Affiliation(s)
- Manal Galal Abd El Wahab
- Anatomy department, Faculty of Medicine for Girls Al Azhar University, Cairo, Egypt
- Basic Sciences department, Nursing College, King Saud Bin Abd El Aziz University, National guard, Jeddah, Saudi Arabia
- Yousef Abdullatif Jameel, Chair of Prophetic Medical Applications (YAJCPMA), Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Soad Shaker Ali
- Yousef Abdullatif Jameel, Chair of Prophetic Medical Applications (YAJCPMA), Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
- Anatomy department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Nasra Naeim Ayuob
- Anatomy department, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
- Histology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
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Sánchez-Rodríguez I, Temprano-Carazo S, Nájera A, Djebari S, Yajeya J, Gruart A, Delgado-García JM, Jiménez-Díaz L, Navarro-López JD. Activation of G-protein-gated inwardly rectifying potassium (Kir3/GirK) channels rescues hippocampal functions in a mouse model of early amyloid-β pathology. Sci Rep 2017; 7:14658. [PMID: 29116174 PMCID: PMC5676742 DOI: 10.1038/s41598-017-15306-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 10/25/2017] [Indexed: 12/15/2022] Open
Abstract
The hippocampus plays a critical role in learning and memory. Its correct performance relies on excitatory/inhibitory synaptic transmission balance. In early stages of Alzheimer’s disease (AD), neuronal hyperexcitability leads to network dysfunction observed in cortical regions such as the hippocampus. G-protein-gated potassium (GirK) channels induce neurons to hyperpolarize, contribute to the resting membrane potential and could compensate any excesses of excitation. Here, we have studied the relationship between GirK channels and hippocampal function in a mouse model of early AD pathology. Intracerebroventricular injections of amyloid-β (Aβ1-42) peptide—which have a causal role in AD pathogenesis—were performed to evaluate CA3–CA1 hippocampal synapse functionality in behaving mice. Aβ increased the excitability of the CA3–CA1 synapse, impaired long-term potentiation (LTP) and hippocampal oscillatory activity, and induced deficits in novel object recognition (NOR) tests. Injection of ML297 alone, a selective GirK activator, was also translated in LTP and NOR deficits. However, increasing GirK activity rescued all hippocampal deficits induced by Aβ due to the restoration of excitability values in the CA3–CA1 synapse. Our results show a synaptic mechanism, through GirK channel modulation, for the prevention of the hyperexcitability that causally contributes to synaptic, network, and cognitive deficits found in early AD pathogenesis.
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Affiliation(s)
- Irene Sánchez-Rodríguez
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain
| | - Sara Temprano-Carazo
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain
| | - Alberto Nájera
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain
| | - Souhail Djebari
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain
| | - Javier Yajeya
- University of Salamanca, Instituto de Neurociencias de Castilla y León, Salamanca, Spain
| | - Agnès Gruart
- Pablo de Olavide University, Division of Neurosciences, Seville, Spain
| | | | - Lydia Jiménez-Díaz
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain.
| | - Juan D Navarro-López
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, Ciudad Real, Spain.
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Mattana S, Caponi S, Tamagnini F, Fioretto D, Palombo F. Viscoelasticity of amyloid plaques in transgenic mouse brain studied by Brillouin microspectroscopy and correlative Raman analysis. JOURNAL OF INNOVATIVE OPTICAL HEALTH SCIENCES 2017; 10:1742001. [PMID: 29151920 PMCID: PMC5687568 DOI: 10.1142/s1793545817420019] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Amyloidopathy is one of the most prominent hallmarks of Alzheimer's disease (AD), the leading cause of dementia worldwide, and is characterized by the accumulation of amyloid plaques in the brain parenchyma. The plaques consist of abnormal deposits mainly composed of an aggregation-prone protein fragment, β-amyloid 1-40/1-42, into the extracellular matrix. Brillouin microspectroscopy is an all-optical contactless technique that is based on the interaction between visible light and longitudinal acoustic waves or phonons, giving access to the viscoelasticity of a sample on a subcellular scale. Here, we describe the first application of micromechanical mapping based on Brillouin scattering spectroscopy to probe the stiffness of individual amyloid plaques in the hippocampal part of the brain of a β-amyloid overexpressing transgenic mouse. Correlative analysis based on Brillouin and Raman microspectroscopy showed that amyloid plaques have a complex structure with a rigid core of β-pleated sheet conformation (β-amyloid) protein surrounded by a softer ring-shaped region richer in lipids and other protein conformations. These preliminary results give a new insight into the plaque biophysics and biomechanics, and a valuable contrast mechanism for the study and diagnosis of amyloidopathy.
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Affiliation(s)
- Sara Mattana
- Department of Physics and Geology, University of Perugia, Perugia I-06123, Italy
| | - Silvia Caponi
- Istituto Officina dei Materiali del CNR (CNR-IOM) - Unità di Perugia Department of Physics and Geology, University of Perugia, Perugia I-06123, Italy
| | - Francesco Tamagnini
- Hatherly Laboratories, Medical School University of Exeter, Exeter EX4 4PS, UK
| | - Daniele Fioretto
- Department of Physics and Geology, University of Perugia, Perugia I-06123, Italy
| | - Francesca Palombo
- School of Physics and Astronomy, University of Exeter, Exeter EX4 4QL, UK
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Hu T, Xiao Z, Mao R, Chen B, Lu MN, Tong J, Mei R, Li SS, Xiao ZC, Zhang LF, Xiyang YB. Navβ2 knockdown improves cognition in APP/PS1 mice by partially inhibiting seizures and APP amyloid processing. Oncotarget 2017; 8:99284-99295. [PMID: 29245901 PMCID: PMC5725092 DOI: 10.18632/oncotarget.21849] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 10/02/2017] [Indexed: 11/25/2022] Open
Abstract
Voltage-gated sodium channels beta 2 (Navβ2, encoded by SCN2B) is a substrate of β-site amyloid precursor protein cleaving enzyme 1 (BACE1) and regulates cell surface expression of channels in neurons. Previous studies reported enhanced Navβ2 processing by BACE1 in Alzheimer’s disease (AD) model and patients. We investigated whether changes in Navβ2 expression affect neuronal seizure and amyloid precursor protein (APP) processing in an AD mouse model. Our study used eight-month-old APP/presenilin 1 (PS1) mice and transgenic Navβ2 knockdown [by 61% vs. wild type (WT)] APP/PS1 mice (APP/PS1/Navβ2-kd), with age-matched WT and Navβ2 knockdown (Navβ2-kd) mice as controls. We found that Navβ2 knockdown in APP/PS1 mice partially reversed the abnormal Navβ2 cleavage and the changes in intracellular and total Nav1.1α expression. It also restored sodium currents density in hippocampal neurons and neuronal activity, as indicated by EEG tracing; improved Morris water maze performance; and shifted APP amyloidogenic metabolism towards non-amyloidogenic processing. There were no differences in these indicators between WT and Navβ2-kd mice. These results suggest Navβ2 knockdown may be a promising strategy for treating AD.
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Affiliation(s)
- Tao Hu
- Institute of Neuroscience, Basic Medical College, Kunming Medical University, Kunming, Yunnan, PR China.,Department of Laboratory Medicine, The Third People's Hospital of Yunnan Province, Kunming, Yunnan, PR China
| | - Zhangang Xiao
- Laboratory of Molecular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China.,Key Laboratory of Medical Electrophysiology, Ministry of Education, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, PR China
| | - Rui Mao
- School of Stomatology, Kunming Medical University, Kunming, Yunnan, PR China
| | - Bo Chen
- Experiment Center for Medical Science Research, Kunming Medical University, Kunming, Yunnan, PR China
| | - Min-Nan Lu
- Experiment Center for Medical Science Research, Kunming Medical University, Kunming, Yunnan, PR China
| | - Jun Tong
- Physical Education Department, Kunming Medical University, Kunming, Yunnan, PR China
| | - Rong Mei
- Department of Neurology, The First People's Hospital of Yunnan Province, Kunming, Yunnan, PR China
| | - Shan-Shan Li
- Basic Medical College, Kunming Medical University, Kunming, Yunnan, PR China
| | - Zhi-Cheng Xiao
- Institute of Molecular and Clinical Medicine, Kunming Medical University, Kunming, Yunnan, PR China.,Monash Immunology and Stem Cell Laboratories (MISCL), Monash University, Clayton, VIC, Australia
| | - Lian-Feng Zhang
- Key Laboratory of Human Diseases Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences(CAMS) & Comparative Medicine Centre, Peking Union Medical College (PUMC), Beijing, China
| | - Yan-Bin Xiyang
- Institute of Neuroscience, Basic Medical College, Kunming Medical University, Kunming, Yunnan, PR China
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Angulo SL, Orman R, Neymotin SA, Liu L, Buitrago L, Cepeda-Prado E, Stefanov D, Lytton WW, Stewart M, Small SA, Duff KE, Moreno H. Tau and amyloid-related pathologies in the entorhinal cortex have divergent effects in the hippocampal circuit. Neurobiol Dis 2017; 108:261-276. [PMID: 28860088 DOI: 10.1016/j.nbd.2017.08.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/09/2017] [Accepted: 08/26/2017] [Indexed: 02/02/2023] Open
Abstract
The entorhinal cortex (EC) is affected early in Alzheimer's disease, an illness defined by a co-occurrence of tau and amyloid-related pathologies. How the co-occurrence of these pathologies in the EC affects the hippocampal circuit remains unknown. Here we address this question by performing electrophysiological analyses of the EC circuit in mice that express mutant human amyloid precursor protein (hAPP) or tau (hTau), or both in the EC. We show that the alterations in the hippocampal circuit are divergent, with hAPP increasing but hTau decreasing neuronal/circuit excitability. Most importantly, mice co-expressing hAPP and hTau show that hTau has a dominant effect, dampening the excitatory effects of hAPP. Additionally, compensatory synaptic downscaling, in response to increased excitability in EC was observed in subicular neurons of hAPP mice. Based on simulations, we propose that EC interneuron pruning can account for both EC hyperexcitability and subicular synaptic downscaling found in mice expressing hAPP.
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Affiliation(s)
- S L Angulo
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States; The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - R Orman
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - S A Neymotin
- Department of Neuroscience, Brown University, Providence, RI 02912, United States
| | - L Liu
- Department of Pathology, Cell Biology, Columbia University Medical Center, NY 10032, United States; Department of Psychiatry, Columbia University Medical Center, NY 10032, United States
| | - L Buitrago
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States; The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - E Cepeda-Prado
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States; The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - D Stefanov
- Scientific Computer Center, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - W W Lytton
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States; The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - M Stewart
- The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States
| | - S A Small
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, NY 10032, United States; Department of Neurology, Columbia University Medical Center, NY 10032, United States
| | - K E Duff
- Department of Pathology, Cell Biology, Columbia University Medical Center, NY 10032, United States; Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, NY 10032, United States; Department of Psychiatry, Columbia University Medical Center, NY 10032, United States
| | - H Moreno
- Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States; The Robert F. Furchgott Center for Neural and Behavioral Science, Department of Physiology/Pharmacology, SUNY Downstate Medical Center, Brooklyn, NY 11203, United States.
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Tamagnini F, Walsh DA, Brown JT, Bondulich MK, Hanger DP, Randall AD. Hippocampal neurophysiology is modified by a disease-associated C-terminal fragment of tau protein. Neurobiol Aging 2017; 60:44-56. [PMID: 28917666 PMCID: PMC5654728 DOI: 10.1016/j.neurobiolaging.2017.07.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/26/2017] [Accepted: 07/11/2017] [Indexed: 01/09/2023]
Abstract
The accumulation of cleaved tau fragments in the brain is associated with several tauopathies. For this reason, we recently developed a transgenic mouse that selectively accumulates a C-Terminal 35 kDa human tau fragment (Tau35). These animals develop progressive motor and spatial memory impairment, paralleled by increased hippocampal glycogen synthase kinase 3β activity. In this neurophysiological study, we focused on the CA1 subfield of the hippocampus, a brain area involved in memory encoding. The accumulation of Tau35 results in a significant increase of short-term facilitation of the synaptic response in the theta frequency range (10 Hz), without affecting basal synaptic transmission and long-term synaptic plasticity. Tau35 expression also alters the intrinsic excitability of CA1 pyramidal neurons. Thus, Tau35 presence is associated with increased and decreased excitability at hyperpolarized and depolarized potentials, respectively. These observations are paralleled by a hyperpolarization of the voltage-sensitivity of noninactivating K+ currents. Further investigation is needed to assess the causal link between such functional alterations and the cognitive and motor impairments previously observed in this model.
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Affiliation(s)
- Francesco Tamagnini
- Institute of Clinical and Biomedical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK.
| | - Darren A Walsh
- Institute of Clinical and Biomedical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Jon T Brown
- Institute of Clinical and Biomedical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Marie K Bondulich
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Diane P Hanger
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - Andrew D Randall
- Institute of Clinical and Biomedical Sciences, University of Exeter Medical School, University of Exeter, Exeter, UK
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Berkowitz BA, Lenning J, Khetarpal N, Tran C, Wu JY, Berri AM, Dernay K, Haacke EM, Shafie-Khorassani F, Podolsky RH, Gant JC, Maimaiti S, Thibault O, Murphy GG, Bennett BM, Roberts R. In vivo imaging of prodromal hippocampus CA1 subfield oxidative stress in models of Alzheimer disease and Angelman syndrome. FASEB J 2017; 31:4179-4186. [PMID: 28592637 DOI: 10.1096/fj.201700229r] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 05/22/2017] [Indexed: 12/13/2022]
Abstract
Hippocampus oxidative stress is considered pathogenic in neurodegenerative diseases, such as Alzheimer disease (AD), and in neurodevelopmental disorders, such as Angelman syndrome (AS). Yet clinical benefits of antioxidant treatment for these diseases remain unclear because conventional imaging methods are unable to guide management of therapies in specific hippocampus subfields in vivo that underlie abnormal behavior. Excessive production of paramagnetic free radicals in nonhippocampus brain tissue can be measured in vivo as a greater-than-normal 1/T1 that is quenchable with antioxidant as measured by quench-assisted (Quest) MRI. Here, we further test this approach in phantoms, and we present proof-of-concept data in models of AD-like and AS hippocampus oxidative stress that also exhibit impaired spatial learning and memory. AD-like models showed an abnormal gradient along the CA1 dorsal-ventral axis of excessive free radical production as measured by Quest MRI, and redox-sensitive calcium dysregulation as measured by manganese-enhanced MRI and electrophysiology. In the AS model, abnormally high free radical levels were observed in dorsal and ventral CA1. Quest MRI is a promising in vivo paradigm for bridging brain subfield oxidative stress and behavior in animal models and in human patients to better manage antioxidant therapy in devastating neurodegenerative and neurodevelopmental diseases.-Berkowitz, B. A., Lenning, J., Khetarpal, N., Tran, C., Wu, J. Y., Berri, A. M., Dernay, K., Haacke, E. M., Shafie-Khorassani, F., Podolsky, R. H., Gant, J. C., Maimaiti, S., Thibault, O., Murphy, G. G., Bennett, B. M., Roberts, R. In vivo imaging of prodromal hippocampus CA1 subfield oxidative stress in models of Alzheimer disease and Angelman syndrome.
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Affiliation(s)
- Bruce A Berkowitz
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA; .,Department of Ophthalmology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Jacob Lenning
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Nikita Khetarpal
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Catherine Tran
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Johnny Y Wu
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Ali M Berri
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Kristin Dernay
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - E Mark Haacke
- Department of Radiology, Wayne State University, Detroit, Michigan, USA
| | - Fatema Shafie-Khorassani
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - Robert H Podolsky
- Department of Family Medicine and Public Health Sciences, Wayne State University, Detroit, Michigan, USA
| | - John C Gant
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Shaniya Maimaiti
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Olivier Thibault
- Department of Pharmacology and Nutritional Sciences, University of Kentucky Medical Center, Lexington, Kentucky, USA
| | - Geoffrey G Murphy
- Department of Molecular and Integrative Physiology, Molecular Behavioral Neuroscience Institute, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Brian M Bennett
- Centre for Neuroscience Studies, Department of Biomedical and Molecular Sciences, Faculty of Health Sciences, Queen's University, Kingston, Ontario, Canada
| | - Robin Roberts
- Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, Michigan, USA
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Niere F, Raab-Graham KF. mTORC1 Is a Local, Postsynaptic Voltage Sensor Regulated by Positive and Negative Feedback Pathways. Front Cell Neurosci 2017; 11:152. [PMID: 28611595 PMCID: PMC5447718 DOI: 10.3389/fncel.2017.00152] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/09/2017] [Indexed: 12/11/2022] Open
Abstract
The mammalian/mechanistic target of rapamycin complex 1 (mTORC1) serves as a regulator of mRNA translation. Recent studies suggest that mTORC1 may also serve as a local, voltage sensor in the postsynaptic region of neurons. Considering biochemical, bioinformatics and imaging data, we hypothesize that the activity state of mTORC1 dynamically regulates local membrane potential by promoting and repressing protein synthesis of select mRNAs. Our hypothesis suggests that mTORC1 uses positive and negative feedback pathways, in a branch-specific manner, to maintain neuronal excitability within an optimal range. In some dendritic branches, mTORC1 activity oscillates between the "On" and "Off" states. We define this as negative feedback. In contrast, positive feedback is defined as the pathway that leads to a prolonged depolarized or hyperpolarized resting membrane potential, whereby mTORC1 activity is constitutively on or off, respectively. We propose that inactivation of mTORC1 increases the expression of voltage-gated potassium alpha (Kv1.1 and 1.2) and beta (Kvβ2) subunits, ensuring that the membrane resets to its resting membrane potential after experiencing increased synaptic activity. In turn, reduced mTORC1 activity increases the protein expression of syntaxin-1A and promotes the surface expression of the ionotropic glutamate receptor N-methyl-D-aspartate (NMDA)-type subunit 1 (GluN1) that facilitates increased calcium entry to turn mTORC1 back on. Under conditions such as learning and memory, mTORC1 activity is required to be high for longer periods of time. Thus, the arm of the pathway that promotes syntaxin-1A and Kv1 protein synthesis will be repressed. Moreover, dendritic branches that have low mTORC1 activity with increased Kv expression would balance dendrites with constitutively high mTORC1 activity, allowing for the neuron to maintain its overall activity level within an ideal operating range. Finally, such a model suggests that recruitment of more positive feedback dendritic branches within a neuron is likely to lead to neurodegenerative disorders.
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Affiliation(s)
- Farr Niere
- Department of Physiology and Pharmacology, Wake Forest School of MedicineWinston-Salem, NC, United States
| | - Kimberly F. Raab-Graham
- Department of Physiology and Pharmacology, Wake Forest School of MedicineWinston-Salem, NC, United States
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Amyloid precursor protein modulates Nav1.6 sodium channel currents through a Go-coupled JNK pathway. Sci Rep 2016; 6:39320. [PMID: 28008944 PMCID: PMC5180232 DOI: 10.1038/srep39320] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/17/2016] [Indexed: 02/08/2023] Open
Abstract
Amyloid precursor protein (APP), commonly associated with Alzheimer’s disease, also marks axonal degeneration. In the recent studies, we demonstrated that APP aggregated at nodes of Ranvier (NORs) in myelinated central nervous system (CNS) axons and interacted with Nav1.6. However, the physiological function of APP remains unknown. In this study, we described reduced sodium current densities in APP knockout hippocampal neurons. Coexpression of APP or its intracellular domains containing a VTPEER motif with Nav1.6 sodium channels in Xenopus oocytes resulted in an increase in peak sodium currents, which was enhanced by constitutively active Go mutant and blocked by a dominant negative mutant. JNK and CDK5 inhibitor attenuated increases in Nav1.6 sodium currents induced by overexpression of APP. Nav1.6 sodium currents were increased by APPT668E (mutant Thr to Glu) and decreased by T668A (mutant Thr to ALa) mutant, respectively. The cell surface expression of Nav1.6 sodium channels in the white matter of spinal cord and the spinal conduction velocity is decreased in APP, p35 and JNK3 knockout mice. Therefore, APP modulates Nav1.6 sodium channels through a Go-coupled JNK pathway, which is dependent on phosphorylation of APP at Thr668.
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Hu B, Geng C, Hou XY. Oligomeric amyloid-β peptide disrupts olfactory information output by impairment of local inhibitory circuits in rat olfactory bulb. Neurobiol Aging 2016; 51:113-121. [PMID: 28061384 DOI: 10.1016/j.neurobiolaging.2016.12.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/22/2016] [Accepted: 12/05/2016] [Indexed: 11/27/2022]
Abstract
Although early olfactory dysfunction has been found in patients with Alzheimer's disease, the underlying mechanisms remain unclear. In this study, we investigated whether and how oligomeric amyloid-β peptide (Aβ) affects the responses of mitral cells (MCs). We found that oligomeric Aβ1-42 increased spontaneous and evoked firing rates but decreased the ratio of evoked to spontaneous firings in MCs. Aβ1-42 oligomers showed no impact on the hyperactivity exerted by pharmacological blockage of GABAA receptors, suggesting an involvement of GABAergic inhibitory transmission in Aβ1 to 42-induced over-excitability. It was further determined that Aβ1-42 oligomers inhibited the frequency of spontaneous inhibitory postsynaptic currents and miniature inhibitory postsynaptic currents, as well as the amplitude of miniature inhibitory postsynaptic currents in MCs. Both recurrent and lateral inhibition of MCs, which are critical for odor discrimination, were also disrupted by Aβ1-42 oligomers. The above data indicate that Aβ impairs local inhibitory circuits and thereby leads to perturbations of olfactory information output in the olfactory bulb. This study reveals a cellular and synaptic basis of olfactory deficits associated with Alzheimer's disease.
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Affiliation(s)
- Bin Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, Jiangsu, China; Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Jiangsu, China; Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Jiangsu, China
| | - Chi Geng
- Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Jiangsu, China; Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Jiangsu, China
| | - Xiao-Yu Hou
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanjing Medical University, Jiangsu, China; Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Jiangsu, China; Research Center for Biochemistry and Molecular Biology, Xuzhou Medical University, Jiangsu, China.
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Lara-Valderrábano L, Rocha L, Galván EJ. Propylparaben reduces the excitability of hippocampal neurons by blocking sodium channels. Neurotoxicology 2016; 57:183-193. [DOI: 10.1016/j.neuro.2016.09.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Revised: 09/13/2016] [Accepted: 09/27/2016] [Indexed: 01/09/2023]
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Westmark CJ, Sokol DK, Maloney B, Lahiri DK. Novel roles of amyloid-beta precursor protein metabolites in fragile X syndrome and autism. Mol Psychiatry 2016; 21:1333-41. [PMID: 27573877 PMCID: PMC5580495 DOI: 10.1038/mp.2016.134] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/20/2016] [Accepted: 06/23/2016] [Indexed: 01/17/2023]
Abstract
Fragile X syndrome (FXS) is the most common form of inherited intellectual disability and is associated with up to 5% of autism cases. Several promising drugs are in preclinical testing for FXS; however, bench-to-bedside plans for the clinic are severely limited due to lack of validated biomarkers and outcome measures. Published work from our laboratories has demonstrated altered levels of amyloid-beta (Aβ) precursor protein (APP) and its metabolites in FXS and idiopathic autism. Westmark and colleagues have focused on β-secretase (amyloidogenic) processing and the accumulation of Aβ peptides in adult FXS models, whereas Lahiri and Sokol have studied α-secretase (non-amyloidogenic or anabolic) processing and altered levels of sAPPα and Aβ in pediatric autism and FXS. Thus, our groups have hypothesized a pivotal role for these Alzheimer's disease (AD)-related proteins in the neurodevelopmental disorders of FXS and autism. In this review, we discuss the contribution of APP metabolites to FXS and autism pathogenesis as well as the potential use of these metabolites as blood-based biomarkers and therapeutic targets. Our future focus is to identify key underlying mechanisms through which APP metabolites contribute to FXS and autism condition-to-disease pathology. Positive outcomes will support utilizing APP metabolites as blood-based biomarkers in clinical trials as well as testing drugs that modulate APP processing as potential disease therapeutics. Our studies to understand the role of APP metabolites in developmental conditions such as FXS and autism are a quantum leap for the neuroscience field, which has traditionally restricted any role of APP to AD and aging.
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Affiliation(s)
- Cara J. Westmark
- University of Wisconsin, Department of Neurology, Madison, WI, USA
| | - Deborah K. Sokol
- Indiana University School of Medicine, Department of Psychiatry, Institute of Psychiatric Research, Indianapolis, IN USA
| | - Bryan Maloney
- Indiana University School of Medicine, Department of Psychiatry, Institute of Psychiatric Research, Indianapolis, IN USA
| | - Debomoy K. Lahiri
- Indiana University School of Medicine, Department of Psychiatry, Institute of Psychiatric Research, Indianapolis, IN USA
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Masuzzo A, Dinet V, Cavanagh C, Mascarelli F, Krantic S. Amyloidosis in Retinal Neurodegenerative Diseases. Front Neurol 2016; 7:127. [PMID: 27551275 PMCID: PMC4976396 DOI: 10.3389/fneur.2016.00127] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 07/27/2016] [Indexed: 01/18/2023] Open
Abstract
As a part of the central nervous system, the retina may reflect both physiological processes and abnormalities related to pathologies that affect the brain. Amyloidosis due to the accumulation of amyloid-beta (Aβ) was initially regarded as a specific and exclusive characteristic of neurodegenerative alterations seen in the brain of Alzheimer's disease (AD) patients. More recently, it was discovered that amyloidosis-related alterations, similar to those seen in the brain of Alzheimer's patients, also occur in the retina. Remarkably, these alterations were identified not only in primary retinal pathologies, such as age-related macular degeneration (AMD) and glaucoma, but also in the retinas of Alzheimer's patients. In this review, we first briefly discuss the biogenesis of Aβ, a peptide involved in amyloidosis. We then discuss some pathological aspects (synaptic dysfunction, mitochondrial failure, glial activation, and vascular abnormalities) related to the neurotoxic effects of Aβ. We finally highlight common features shared by AD, AMD, and glaucoma in the context of Aβ amyloidosis and further discuss why the retina, due to the transparency of the eye, can be considered as a "window" to the brain.
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Affiliation(s)
- Ambra Masuzzo
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Virginie Dinet
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Chelsea Cavanagh
- Department of Neuroscience, Douglas Hospital Research Center , Montreal, QC , Canada
| | - Frederic Mascarelli
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
| | - Slavica Krantic
- Centre de Recherche des Cordeliers, Institut national de la santé et de la recherche médicale (INSERM), Université Paris Descartes, Sorbonne Paris Cité, UMR_S 1138, Université Pierre et Marie Curie Université Paris 06, Sorbonne Universités , Paris , France
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Wang X, Zhang XG, Zhou TT, Li N, Jang CY, Xiao ZC, Ma QH, Li S. Elevated Neuronal Excitability Due to Modulation of the Voltage-Gated Sodium Channel Nav1.6 by Aβ1-42. Front Neurosci 2016; 10:94. [PMID: 27013956 PMCID: PMC4783403 DOI: 10.3389/fnins.2016.00094] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/24/2016] [Indexed: 12/13/2022] Open
Abstract
Aberrant increases in neuronal network excitability may contribute to the cognitive deficits in Alzheimer's disease (AD). However, the mechanisms underlying hyperexcitability are not fully understood. Such overexcitation of neuronal networks has been detected in the brains of APP/PS1 mice. In the present study, using current-clamp recording techniques, we observed that 12 days in vitro (DIV) primary cultured pyramidal neurons from P0 APP/PS1 mice exhibited a more prominent action potential burst and a lower threshold than WT littermates. Moreover, after treatment with Aβ1−42 peptide, 12 DIV primary cultured neurons showed similar changes, to a greater degree than in controls. Voltage-clamp recordings revealed that the voltage-dependent sodium current density of neurons incubated with Aβ1−42 was significantly increased, without change in the voltage-dependent sodium channel kinetic characteristics. Immunohistochemistry and western blot results showed that, after treatment with Aβ1−42, expressions of Nav and Nav1.6 subtype increased in cultured neurons or APP/PS1 brains compared to control groups. The intrinsic neuronal hyperexcitability of APP/PS1 mice might thus be due to an increased expression of voltage-dependent sodium channels induced by Aβ1−42. These results may illuminate the mechanism of aberrant neuronal networks in AD.
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Affiliation(s)
- Xi Wang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Xiao-Gang Zhang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Ting-Ting Zhou
- Department of Neurology, the First Affiliated Hospital of Dalian Medical University Dalian, China
| | - Na Li
- Department of Physiology, Dalian Medical University Dalian, China
| | - Chun-Yan Jang
- Department of Physiology, Dalian Medical University Dalian, China
| | - Zhi-Cheng Xiao
- The Key Laboratory of Stem Cell and Regenerative Medicine, Kunming Medical College, Institute of Molecular and Clinical Medicine Kunming, China
| | - Quan-Hong Ma
- Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases, Institute of Neuroscience, Second Affiliated Hospital, Soochow University Suzhou, China
| | - Shao Li
- Department of Physiology, Dalian Medical University Dalian, China
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50
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Tamagnini F, Novelia J, Kerrigan TL, Brown JT, Tsaneva-Atanasova K, Randall AD. Altered intrinsic excitability of hippocampal CA1 pyramidal neurons in aged PDAPP mice. Front Cell Neurosci 2015; 9:372. [PMID: 26528126 PMCID: PMC4604241 DOI: 10.3389/fncel.2015.00372] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 09/07/2015] [Indexed: 12/28/2022] Open
Abstract
Amyloidopathy involves the accumulation of insoluble amyloid β (Aβ) species in the brain's parenchyma and is a key histopathological hallmark of Alzheimer's disease (AD). Work on transgenic mice that overexpress Aβ suggests that elevated Aβ levels in the brain are associated with aberrant epileptiform activity and increased intrinsic excitability (IE) of CA1 hippocampal neurons. In this study we examined if similar changes could be observed in hippocampal CA1 pyramidal neurons from aged PDAPP mice (20-23 month old, Indiana mutation: V717F on APP gene) compared to their age-matched wild-type littermate controls. Whole-cell current clamp recordings revealed that sub-threshold intrinsic properties, such as input resistance, resting membrane potential and hyperpolarization activated "sag" were unaffected, but capacitance was significantly decreased in the transgenic animals. No differences between genotypes were observed in the overall number of action potentials (AP) elicited by 500 ms supra-threshold current stimuli. PDAPP neurons, however, exhibited higher instantaneous firing frequencies after accommodation in response to high intensity current injections. The AP waveform was narrower and shorter in amplitude in PDAPP mice: these changes, according to our in silico model of a CA1/3 pyramidal neuron, depended on the respective increase and reduction of K(+) and Na(+) voltage-gated channels maximal conductances. Finally, the after-hyperpolarization, seen after the first AP evoked by a +300 pA current injection and after 50 Hz AP bursts, was more pronounced in PDAPP mice. These data show that Aβ-overexpression in aged mice altered the capacitance, the neuronal firing and the AP waveform of CA1 pyramidal neurons. Some of these findings are consistent with previous work on younger PDAPP; they also show important differences that can be potentially ascribed to the interaction between amyloidopathy and ageing. Such a change of IE properties over time underlies that the increased incidence of seizure observed in AD patients might rely on different mechanistic pathways during progression of the disease.
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Affiliation(s)
- Francesco Tamagnini
- Medical School, University of Exeter Exeter, UK ; School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | - Janet Novelia
- Department of Mathematics, College of Engineering, Mathematics and Physical Sciences, University of Exeter Exeter, UK
| | - Talitha L Kerrigan
- Medical School, University of Exeter Exeter, UK ; School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | - Jon T Brown
- Medical School, University of Exeter Exeter, UK ; School of Physiology and Pharmacology, University of Bristol Bristol, UK
| | - Krasimira Tsaneva-Atanasova
- Department of Mathematics, College of Engineering, Mathematics and Physical Sciences, University of Exeter Exeter, UK
| | - Andrew D Randall
- Medical School, University of Exeter Exeter, UK ; School of Physiology and Pharmacology, University of Bristol Bristol, UK
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