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Hole KL, Zhu B, Huggon L, Brown JT, Mason JM, Williams RJ. Tau P301L disengages from the proteosome core complex and neurogranin coincident with enhanced neuronal network excitability. Cell Death Dis 2024; 15:429. [PMID: 38890273 PMCID: PMC11189525 DOI: 10.1038/s41419-024-06815-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 06/04/2024] [Accepted: 06/07/2024] [Indexed: 06/20/2024]
Abstract
Tauopathies are characterised by the pathological accumulation of misfolded tau. The emerging view is that toxic tau species drive synaptic dysfunction and potentially tau propagation before measurable neurodegeneration is evident, but the underlying molecular events are not well defined. Human non-mutated 0N4R tau (tauWT) and P301L mutant 0N4R tau (tauP301L) were expressed in mouse primary cortical neurons using adeno-associated viruses to monitor early molecular changes and synaptic function before the onset of neuronal loss. In this model tauP301L was differentially phosphorylated relative to tauwt with a notable increase in phosphorylation at ser262. Affinity purification - mass spectrometry combined with tandem mass tagging was used to quantitatively compare the tauWT and tauP301L interactomes. This revealed an enrichment of tauP301L with ribosomal proteins but a decreased interaction with the proteasome core complex and reduced tauP301L degradation. Differences in the interaction of tauP301L with members of a key synaptic calcium-calmodulin signalling pathway were also identified, most notably, increased association with CaMKII but reduced association with calcineurin and the candidate AD biomarker neurogranin. Decreased association of neurogranin to tauP301L corresponded with the appearance of enhanced levels of extracellular neurogranin suggestive of potential release or leakage from synapses. Finally, analysis of neuronal network activity using micro-electrode arrays showed that overexpression of tauP301L promoted basal hyperexcitability coincident with these changes in the tau interactome and implicating tau in specific early alterations in synaptic function.
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Affiliation(s)
- Katriona L Hole
- Department of Life Sciences, University of Bath, Bath, UK
- The Francis Crick Institute, London, UK
| | - Bangfu Zhu
- Department of Life Sciences, University of Bath, Bath, UK
| | - Laura Huggon
- Department of Life Sciences, University of Bath, Bath, UK
- UK Dementia Research Institute at King's College London, London, UK
| | - Jon T Brown
- Department of Clinical and Biomedical Sciences, University of Exeter, Exeter, UK
| | - Jody M Mason
- Department of Life Sciences, University of Bath, Bath, UK
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2
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Striebel J, Kalinski L, Sturm M, Drouvé N, Peters S, Lichterfeld Y, Habibey R, Hauslage J, El Sheikh S, Busskamp V, Liemersdorf C. Human neural network activity reacts to gravity changes in vitro. Front Neurosci 2023; 17:1085282. [PMID: 36968488 PMCID: PMC10030604 DOI: 10.3389/fnins.2023.1085282] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/06/2023] [Indexed: 03/11/2023] Open
Abstract
During spaceflight, humans experience a variety of physiological changes due to deviations from familiar earth conditions. Specifically, the lack of gravity is responsible for many effects observed in returning astronauts. These impairments can include structural as well as functional changes of the brain and a decline in cognitive performance. However, the underlying physiological mechanisms remain elusive. Alterations in neuronal activity play a central role in mental disorders and altered neuronal transmission may also lead to diminished human performance in space. Thus, understanding the influence of altered gravity at the cellular and network level is of high importance. Previous electrophysiological experiments using patch clamp techniques and calcium indicators have shown that neuronal activity is influenced by altered gravity. By using multi-electrode array (MEA) technology, we advanced the electrophysiological investigation covering single-cell to network level responses during exposure to decreased (micro-) or increased (hyper-) gravity conditions. We continuously recorded in real-time the spontaneous activity of human induced pluripotent stem cell (hiPSC)-derived neural networks in vitro. The MEA device was integrated into a custom-built environmental chamber to expose the system with neuronal cultures to up to 6 g of hypergravity on the Short-Arm Human Centrifuge at the DLR Cologne, Germany. The flexibility of the experimental hardware set-up facilitated additional MEA electrophysiology experiments under 4.7 s of high-quality microgravity (10–6 to 10–5 g) in the Bremen drop tower, Germany. Hypergravity led to significant changes in activity. During the microgravity phase, the mean action potential frequency across the neural networks was significantly enhanced, whereas different subgroups of neurons showed distinct behaviors, such as increased or decreased firing activity. Our data clearly demonstrate that gravity as an environmental stimulus triggers changes in neuronal activity. Neuronal networks especially reacted to acute changes in mechanical loading (hypergravity) or de-loading (microgravity). The current study clearly shows the gravity-dependent response of neuronal networks endorsing the importance of further investigations of neuronal activity and its adaptive responses to micro- and hypergravity. Our approach provided the basis for the identification of responsible mechanisms and the development of countermeasures with potential implications on manned space missions.
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Affiliation(s)
- Johannes Striebel
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Laura Kalinski
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Maximilian Sturm
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Nils Drouvé
- Department of Applied Sciences, Cologne University of Applied Sciences, Leverkusen, Germany
| | - Stefan Peters
- Department of Applied Sciences, Cologne University of Applied Sciences, Leverkusen, Germany
| | - Yannick Lichterfeld
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Rouhollah Habibey
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Jens Hauslage
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
| | - Sherif El Sheikh
- Department of Applied Sciences, Cologne University of Applied Sciences, Leverkusen, Germany
| | - Volker Busskamp
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Liemersdorf
- Department of Gravitational Biology, Institute of Aerospace Medicine, German Aerospace Center, Cologne, Germany
- *Correspondence: Christian Liemersdorf,
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3
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Erofeev A, Kazakov D, Makarevich N, Bolshakova A, Gerasimov E, Nekrasov A, Kazakin A, Komarevtsev I, Bolsunovskaja M, Bezprozvanny I, Vlasova O. An Open-Source Wireless Electrophysiological Complex for In Vivo Recording Neuronal Activity in the Rodent's Brain. SENSORS 2021; 21:s21217189. [PMID: 34770498 PMCID: PMC8587815 DOI: 10.3390/s21217189] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/19/2021] [Accepted: 10/26/2021] [Indexed: 01/14/2023]
Abstract
Multi-electrode arrays (MEAs) are a widely used tool for recording neuronal activity both in vitro/ex vivo and in vivo experiments. In the last decade, researchers have increasingly used MEAs on rodents in vivo. To increase the availability and usability of MEAs, we have created an open-source wireless electrophysiological complex. The complex is scalable, recording the activity of neurons in the brain of rodents during their behavior. Schematic diagrams and a list of necessary components for the fabrication of a wireless electrophysiological complex, consisting of a base charging station and wireless wearable modules, are presented.
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Affiliation(s)
- Alexander Erofeev
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.B.); (E.G.); (I.B.)
- Correspondence: (A.E.); (O.V.)
| | - Dmitriy Kazakov
- National Technology Initiative Center for Advanced Manufacturing Technologies, Laboratory of Industrial Data Streaming Systems, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (D.K.); (N.M.); (M.B.)
| | - Nikita Makarevich
- National Technology Initiative Center for Advanced Manufacturing Technologies, Laboratory of Industrial Data Streaming Systems, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (D.K.); (N.M.); (M.B.)
| | - Anastasia Bolshakova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.B.); (E.G.); (I.B.)
| | - Evgenii Gerasimov
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.B.); (E.G.); (I.B.)
| | - Arseniy Nekrasov
- Neuropribor, Limited Liability Company, 194223 Saint Petersburg, Russia;
| | - Alexey Kazakin
- Laboratory of Nano- and Microsystem Technology, Joint Institute of Science and Technology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.K.); (I.K.)
| | - Ivan Komarevtsev
- Laboratory of Nano- and Microsystem Technology, Joint Institute of Science and Technology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.K.); (I.K.)
| | - Marina Bolsunovskaja
- National Technology Initiative Center for Advanced Manufacturing Technologies, Laboratory of Industrial Data Streaming Systems, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (D.K.); (N.M.); (M.B.)
| | - Ilya Bezprozvanny
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.B.); (E.G.); (I.B.)
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Olga Vlasova
- Laboratory of Molecular Neurodegeneration, Graduate School of Biomedical Systems and Technologies, Institute of Biomedical Systems and Biotechnology, Peter the Great St. Petersburg Polytechnic University, 195251 Saint Petersburg, Russia; (A.B.); (E.G.); (I.B.)
- Correspondence: (A.E.); (O.V.)
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4
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Schulte S, Gries M, Christmann A, Schäfer KH. Using multielectrode arrays to investigate neurodegenerative effects of the amyloid-beta peptide. Bioelectron Med 2021; 7:15. [PMID: 34711287 PMCID: PMC8554832 DOI: 10.1186/s42234-021-00078-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/05/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Multielectrode arrays are widely used to analyze the effects of potentially toxic compounds, as well as to evaluate neuroprotective agents upon the activity of neural networks in short- and long-term cultures. Multielectrode arrays provide a way of non-destructive analysis of spontaneous and evoked neuronal activity, allowing to model neurodegenerative diseases in vitro. Here, we provide an overview on how these devices are currently used in research on the amyloid-β peptide and its role in Alzheimer's disease, the most common neurodegenerative disorder. MAIN BODY Most of the studies analysed here indicate fast responses of neuronal cultures towards aggregated forms of amyloid-β, leading to increases of spike frequency and impairments of long-term potentiation. This in turn suggests that this peptide might play a crucial role in causing the typical neuronal dysfunction observed in patients with Alzheimer's disease. CONCLUSIONS Although the number of studies using multielectrode arrays to examine the effect of the amyloid-β peptide onto neural cultures or whole compartments is currently limited, they still show how this technique can be used to not only investigate the interneuronal communication in neural networks, but also making it possible to examine the effects onto synaptic currents. This makes multielectrode arrays a powerful tool in future research on neurodegenerative diseases.
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Affiliation(s)
- Steven Schulte
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Manuela Gries
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Anne Christmann
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
| | - Karl-Herbert Schäfer
- Department of Informatics and Microsystems and Technology, University of Applied Science Kaiserslautern, 66482 Zweibrücken, Germany
- Department of Pediatric Surgery, Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
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5
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Duc P, Vignes M, Hugon G, Sebban A, Carnac G, Malyshev E, Charlot B, Rage F. Human neuromuscular junction on micro-structured microfluidic devices implemented with a custom micro electrode array (MEA). LAB ON A CHIP 2021; 21:4223-4236. [PMID: 34559171 DOI: 10.1039/d1lc00497b] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In the neuromuscular system, signal transmission from motor neurons (MNs) to innervated muscle fibers is crucial for their synaptic function, viability, and maintenance. In order to better understand human neuromuscular junction (hNMJ) functionality, it is important to develop on-a-chip devices with human cells. To investigate this cell network, microfluidic platforms are useful to grow different cell types in isolated compartments. Such devices have already been developed to study in vitro neuronal circuitry. Here, we combined microfluidics with two techniques: soft lithography and custom microelectrodes array (MEA). Our goal was to create hNMJs on a specific pattern of electrodes to stimulate pre-synaptic axons and record post-synaptic muscle activity. Micromachining was used to create structurations to guide muscle growth above electrodes, without impairing axon propagation, therefore optimizing the effectiveness of activity recording. Electrodes were also arranged to be aligned with the microfluidic chambers in order to specifically stimulate axons that were growing between the two compartments. Isolation of the two cell types allows for the selective treatment of neurons or muscle fibers to assess NMJ functionality hallmarks. Altogether, this microfluidic/microstructured/MEA platform allowed mature and functional in vitro hNMJ modelling. We demonstrate that electrical activation of MNs can trigger recordable extracellular muscle action potentials. This study provides evidence for a physiologically relevant model to mimic a hNMJ that will in the future be a powerful tool, more sensitive than calcium imaging, to better understand and characterize NMJs and their disruption in neurodegenerative diseases.
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Affiliation(s)
- Pauline Duc
- IGMM, University of Montpellier, CNRS, Montpellier, France.
| | - Michel Vignes
- IBMM UMR5247, University of Montpellier, CNRS, Montpellier, France
| | - Gérald Hugon
- PhyMedExp, INSERM U1046, CNRS UMR9214, Université de Montpellier, Montpellier, France
| | - Audrey Sebban
- IES, CNRS University of Montpellier, Montpellier 34095, France
| | - Gilles Carnac
- PhyMedExp, INSERM U1046, CNRS UMR9214, Université de Montpellier, Montpellier, France
| | - Eugene Malyshev
- IES, CNRS University of Montpellier, Montpellier 34095, France
| | - Benoît Charlot
- IES, CNRS University of Montpellier, Montpellier 34095, France
| | - Florence Rage
- IGMM, University of Montpellier, CNRS, Montpellier, France.
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6
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Cuestas Torres DM, Cardenas FP. Synaptic plasticity in Alzheimer's disease and healthy aging. Rev Neurosci 2021; 31:245-268. [PMID: 32250284 DOI: 10.1515/revneuro-2019-0058] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 11/01/2019] [Indexed: 12/17/2022]
Abstract
The strength and efficiency of synaptic connections are affected by the environment or the experience of the individual. This property, called synaptic plasticity, is directly related to memory and learning processes and has been modeled at the cellular level. These types of cellular memory and learning models include specific stimulation protocols that generate a long-term strengthening of the synapses, called long-term potentiation, or a weakening of the said long-term synapses, called long-term depression. Although, for decades, researchers have believed that the main cause of the cognitive deficit that characterizes Alzheimer's disease (AD) and aging was the loss of neurons, the hypothesis of an imbalance in the cellular and molecular mechanisms of synaptic plasticity underlying this deficit is currently widely accepted. An understanding of the molecular and cellular changes underlying the process of synaptic plasticity during the development of AD and aging will direct future studies to specific targets, resulting in the development of much more efficient and specific therapeutic strategies. In this review, we classify, discuss, and describe the main findings related to changes in the neurophysiological mechanisms of synaptic plasticity in excitatory synapses underlying AD and aging. In addition, we suggest possible mechanisms in which aging can become a high-risk factor for the development of AD and how its development could be prevented or slowed.
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Affiliation(s)
- Diana Marcela Cuestas Torres
- Departamento de Psicología and Departamento de Biología, Laboratorio de Neurociencia y Comportamiento, Universidad de los Andes, Cra 1 N° 18A-12, CP 111711, Bogotá, Colombia
| | - Fernando P Cardenas
- Departamento de Psicología, Laboratorio de Neurociencia y Comportamiento, Universidad de los Andes, Cra 1 N° 18A-12, CP 111711, Bogotá, Colombia
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7
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Darch HT, Collins MK, O'Riordan KJ, Cryan JF. Microbial memories: Sex-dependent impact of the gut microbiome on hippocampal plasticity. Eur J Neurosci 2021; 54:5235-5244. [PMID: 33458858 PMCID: PMC8451864 DOI: 10.1111/ejn.15119] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 02/06/2023]
Abstract
Germ‐free rodents, raised in the absence of a measurable gut microbiome, have been a key model to study the microbiome‐gut‐brain axis. Germ‐free mice exhibit marked behavioural and neurochemical differences to their conventionally raised counterparts. It is as yet unclear how these neurochemical differences lead to the behavioural differences. Here, we test the electrophysiological properties of hippocampal plasticity in adult germ‐free mice and compare them to conventionally raised counterparts. Whilst basal synaptic efficacy and pre‐synaptic short‐term plasticity appear normal, we find a striking alteration of hippocampal long‐term potentiation specifically in male germ‐free slices. However, the spike output of these neurons remains normal along with altered input‐output coupling, potentially indicating homeostatic compensatory mechanisms, or an altered excitation/inhibition balance. To our knowledge this is the first time the electrophysiological properties of the hippocampus have been assessed in a microbiome deficient animal. Our data indicate that the absence of a microbiome alters integration of dendritic signalling in the CA1 region in mice.
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Affiliation(s)
- Henry T Darch
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | | | | | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland.,Anatomy & Neuroscience, University College Cork, Cork, Ireland
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8
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Dong L, Li G, Gao Y, Lin L, Zhang KH, Tian CX, Cao XB, Zheng Y. Effect of priming low-frequency magnetic fields on zero-Mg2+ -induced epileptiform discharges in rat hippocampal slices. Epilepsy Res 2020; 167:106464. [DOI: 10.1016/j.eplepsyres.2020.106464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 09/02/2020] [Accepted: 09/05/2020] [Indexed: 12/16/2022]
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9
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Kim D, Kang H, Nam Y. Compact 256-channel multi-well microelectrode array system for in vitro neuropharmacology test. LAB ON A CHIP 2020; 20:3410-3422. [PMID: 32785330 DOI: 10.1039/d0lc00384k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Microelectrode arrays (MEAs) have been extensively used to measure extracellular spike activity from cultured neurons using multiple electrodes embedded in a planar glass substrate. This system has been implemented to investigate drug effects by detecting pharmacological perturbation reflected in spontaneous network activity. By configuring multiple wells in an MEA, a high-throughput electrophysiological assay has become available, speeding up drug tests. Despite its merits in acquiring massive amounts of electrophysiological data, the high cost and the bulky size of commercial multi-well MEA systems and most importantly its lack of customizability prevent potential users from fully implementing the system in drug experiments. In this work, we have developed a microelectrode array based drug testing platform by incorporating a custom-made compact 256-channel multi-well MEA in a standard microscope slide and commercial application-specific integrated circuit (ASIC) chip based recording system. We arranged 256 electrodes in 16 wells to maximize data collection from a single chip. The multi-well MEA in this work has a more compact design with reduced chip size compared to previously reported multi-well MEAs. Four synaptic modulators (NMDA, AMPA, bicuculline (BIC) and ATP) were applied to a multi-well MEA and neural spike activity was analyzed to study their neurophysiological effects on cultured neurons. Analyzing various neuropharmacological compounds has become much more accessible by utilizing commercially available digital amplifier chips and customizing a user-preferred analog-front-end interface design with additional benefits in reduced platform size and cost.
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Affiliation(s)
- Daejeong Kim
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea.
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10
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Müller-Thomsen L, Borgmann D, Morcinek K, Schröder S, Dengler B, Moser N, Neumaier F, Schneider T, Schröder H, Huggenberger S. Consequences of hyperphosphorylated tau on the morphology and excitability of hippocampal neurons in aged tau transgenic mice. Neurobiol Aging 2020; 93:109-123. [PMID: 32278495 DOI: 10.1016/j.neurobiolaging.2020.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Revised: 03/06/2020] [Accepted: 03/10/2020] [Indexed: 12/31/2022]
Abstract
The intracellular accumulation of hyperphosphorylated tau characterizes many neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. A critical role for tau is supported by studies in transgenic mouse models expressing the P301L mutation with accumulation of hyperphosphorylated human tau in hippocampal pyramidal neurons of aged mice. Especially, the somatodendritic mislocalization of hyperphosphorylated tau seems to affect the neuronal network of the hippocampus. To show the consequences of aggregation of hyperphosphorylated tau within hippocampal neurons of aged mice, the CA1 pyramidal cells were analyzed morphologically and electrophysiologically. Here we demonstrate in the P301L pR5 mouse model that hyperphosphorylated tau leads to an increase in stubby spines and filopodia, as well as a decrease in total dendritic length of hippocampal pyramidal neurons due to a decrease in apical dendritic length and nodes. This atrophy is in line with the significant reduction in CA1 long-term potentiation. Furthermore, mutant tau induced a depolarized threshold for action potential initiation and an increased current of inward rectifying potassium channels, which should lead, together with the long-term potentiation decrease, to a decreased excitability of CA1 neurons.
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Affiliation(s)
| | - Diba Borgmann
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Kerstin Morcinek
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Sophia Schröder
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Brigitte Dengler
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Natasha Moser
- Department II of Anatomy, University of Cologne, Cologne, Germany
| | - Felix Neumaier
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | - Toni Schneider
- Institute for Neurophysiology, University of Cologne, Cologne, Germany
| | | | - Stefan Huggenberger
- Department II of Anatomy, University of Cologne, Cologne, Germany; Institute of Anatomy and Clinical Morphology, Faculty of Health, Witten/Herdecke University, Witten, Germany
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11
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Zhang L, Tang W, Chao FL, Zhou CN, Jiang L, Zhang Y, Liang X, Tang J, Qi YQ, Yang H, He Q, Zhang SS, Zhu L, Peng Y, Tang Y. Four-month treadmill exercise prevents the decline in spatial learning and memory abilities and the loss of spinophilin-immunoreactive puncta in the hippocampus of APP/PS1 transgenic mice. Neurobiol Dis 2019; 136:104723. [PMID: 31887353 DOI: 10.1016/j.nbd.2019.104723] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 12/20/2019] [Accepted: 12/26/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Previous studies have reported that exercise could improve the plasticity of hippocampal synapses. However, the effects of exercise on synapses in the hippocampus in Alzheimer's disease (AD) are not completely known. METHODS In this study, thirty 12-month-old male APP/PS1 double transgenic mice were randomly divided into a sedentary group (n = 15) and a running group (n = 15). Fifteen 12-month-old male wild-type littermates were assigned to the control group (n = 15). While running mice were assigned to treadmill running for four months, the control mice and sedentary mice did not run during the study period. After Morris water maze testing, five mice in each group were randomly selected for a stereological assessment of spinophilin-immunoreactive puncta in the CA1, CA2-3 and dentate gyrus (DG) of the hippocampus. RESULTS Morris water maze testing revealed that while the learning and memory abilities in sedentary APP/PS1 mice were significantly worse than those in wild-type control mice, the learning and memory abilities in running APP/PS1 mice were significantly better than those in sedentary APP/PS1 mice. The stereological results showed that the spinophilin-immunoreactive puncta numbers of the CA1, CA2-3 and DG in the hippocampus of sedentary APP/PS1 mice were significantly lower than those of wild-type control mice and that the numbers of these spines in the CA1, CA2-3 and DG in the hippocampus of running APP/PS1 mice were significantly higher than those of sedentary APP/PS1 mice. Moreover, a running-induced improvement in spatial learning and memory abilities was significantly correlated with running-induced increases in the spinophilin-immunoreactive puncta numbers in the CA1 and DG of the hippocampus. CONCLUSIONS Four-month treadmill exercise induced a significant improvement in spatial learning and memory abilities and a significant increase in the number of spinophilin-immunoreactive puncta of the CA1, CA2-3 and DG in the hippocampus of APP/PS1 mice. Running-induced improvements in spatial learning and memory abilities were significantly correlated with running-induced increases in the spinophilin-immunoreactive puncta numbers in the CA1 and DG of the hippocampus.
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Affiliation(s)
- Lei Zhang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Wei Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Feng-Lei Chao
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Chun-Ni Zhou
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Lin Jiang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Yi Zhang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Xin Liang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Jing Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Ying-Qiang Qi
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Hao Yang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Qi He
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Shan-Shan Zhang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Lin Zhu
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Yan Peng
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China
| | - Yong Tang
- Department of Histology and Embryology, Chongqing Medical University, Chongqing 400016, PR China; Laboratory of Stem Cell and Tissue Engineering, Chongqing Medical University, Chongqing 400016, PR China.
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12
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Samaey C, Schreurs A, Stroobants S, Balschun D. Early Cognitive and Behavioral Deficits in Mouse Models for Tauopathy and Alzheimer's Disease. Front Aging Neurosci 2019; 11:335. [PMID: 31866856 PMCID: PMC6908963 DOI: 10.3389/fnagi.2019.00335] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 11/19/2019] [Indexed: 12/12/2022] Open
Abstract
Neurocognitive disorders, among which Alzheimer's disease (AD), have become one of the major causes of death in developed countries. No effective disease-modifying therapy is available, possibly because current treatments are administered too late to still be able to intervene in the disease progress. AD is characterized by a gradual onset with subclinical neurobiological and behavioral changes that precede diagnosis with years to even decades. The earlier the diagnosis, the earlier potential treatments can be tested and started. Mouse models are valuable to study the possible causes underlying early phases of neuropathology and their reflection in behavior and other biomarkers, to help improve preclinical detection and diagnosis of AD. Here, we assessed cognitive functioning and social behavior in transgenic mice expressing tau pathology only (Tau-P301L) or a combination of amyloid and tau pathology [amyloid precursor protein (APP)-V717I × Tau-P301L]. The mice were subjected to a variety of behavioral tasks at an age of 3-6 months, i.e., at an early phase of their AD-like pathology. We hypothesized that compared to age-matched wild-type controls, transgenic mice would show specific impairments in both cognitive and non-cognitive tasks. In line with our expectations, transgenic mice showed decreased cognitive flexibility in the Morris water maze, decreased exploratory behavior, decreased performance in a nesting task, and increased anxiety-like behavior. In accordance with the amyloid-cascade hypothesis, some of the behavioral measures showed more severe deficits in APP-V717I × Tau-P301L compared to Tau-P301L mice, indicating an exacerbation of disease processes due to the co-occurrence of amyloid and tau pathology. Our study supports the use of behavioral markers as early indicators of ongoing AD pathology during the preclinical phase.
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Affiliation(s)
- Celine Samaey
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Center for Clinical Psychiatry, KU Leuven, Leuven, Belgium
| | - An Schreurs
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Stijn Stroobants
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Detlef Balschun
- Brain and Cognition, KU Leuven, Leuven, Belgium.,Leuven Brain Institute, KU Leuven, Leuven, Belgium
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13
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Wang Y, Liu Q, Xie J, Feng R, Ma F, Wang F, Shen S, Wen T. Dcf1 Affects Memory and Anxiety by Regulating NMDA and AMPA Receptors. Neurochem Res 2019; 44:2499-2505. [PMID: 31531752 DOI: 10.1007/s11064-019-02866-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 08/17/2019] [Accepted: 08/24/2019] [Indexed: 02/02/2023]
Abstract
The hippocampus is critical for memory and emotion and both N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl- 4-isoxazolepropionic acid (AMPA) receptors are known to contribute for those processes. However, the underlying molecular mechanisms remain poorly understood. We have previously found that mice undergo memory decline upon dcf1 deletion through ES gene knockout. In the present study, a nervous system-specific dcf1 knockout (NKO) mouse was constructed, which was found to present severely damaged neuronal morphology. The damaged neurons caused structural abnormalities in dendritic spines and decreased synaptic density. Decreases in hippocampal NMDA and AMPA receptors of NKO mice lead to abnormal long term potentiation (LTP) at DG, with significantly decreased performance in the water maze, elevated- plus maze, open field and light and dark test. Investigation into the underlying molecular mechanisms revealed that dendritic cell factor 1 (Dcf1) contributes for memory and emotion by regulating NMDA and AMPA receptors. Our results broaden the understanding of synaptic plasticity's role in cognitive function, thereby expanding its known list of functions.
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Affiliation(s)
- Yajiang Wang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Qiang Liu
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Jiayang Xie
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Ruili Feng
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Fangfang Ma
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Fushuai Wang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Shiyi Shen
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China
| | - Tieqiao Wen
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, 381 Nanchen Road, Shanghai, 200444, China.
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14
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Govaerts K, Dresselaers T, Van Leuven F, Himmelreich U. Quantitative Assessment of Age-Associated Alterations in Brain Vasculature in Wild-Type Mice and in Bigenic Mice that Model Alzheimer's Disease. Mol Imaging Biol 2019; 22:578-586. [PMID: 31297706 DOI: 10.1007/s11307-019-01402-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE Vascular dysfunction is a major hallmark of Alzheimer's disease (AD). However, studies that investigated vascular dysfunction in mice modeling AD using magnetic resonance angiography (MRA) are typically limited to qualitative and/or scoring-based paradigms, which are labor-intensive and observer-dependent. PROCEDURES We developed and validated a semi-automatic MRA processing pipeline and applied this to high-resolution in vivo MRA images acquired on a 9.4T small animal MRI scanner. We assessed vascular morphology at 3, 6, and 12 months in wild-type (WT) and bigenic (APP.V717IxTau.P301L: biAT) mice. RESULTS Vessel radius or length can increase with age regardless of genotype depending on the respective vessel. We also observed significantly lower internal carotid artery length in biAT mice compared to WT. CONCLUSIONS The results demonstrate that even subtle changes in vessel morphology can be noninvasively quantified. This is of great interest for AD, but also to other models of neurodegenerative diseases involving macrovascular dysfunction.
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Affiliation(s)
- Kristof Govaerts
- Biomedical MRI/ MoSAIC, Department of Imaging & Pathology, KU Leuven, Herestraat 49, Bus 505, 3000, Leuven, Belgium
| | - Tom Dresselaers
- Biomedical MRI/ MoSAIC, Department of Imaging & Pathology, KU Leuven, Herestraat 49, Bus 505, 3000, Leuven, Belgium
| | - Fred Van Leuven
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI/ MoSAIC, Department of Imaging & Pathology, KU Leuven, Herestraat 49, Bus 505, 3000, Leuven, Belgium.
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15
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Naseri NN, Wang H, Guo J, Sharma M, Luo W. The complexity of tau in Alzheimer's disease. Neurosci Lett 2019; 705:183-194. [PMID: 31028844 PMCID: PMC7060758 DOI: 10.1016/j.neulet.2019.04.022] [Citation(s) in RCA: 176] [Impact Index Per Article: 35.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 03/14/2019] [Accepted: 04/08/2019] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is characterized by two major pathological lesions in the brain, amyloid plaques and neurofibrillary tangles (NFTs) composed mainly of amyloid-β (Aβ) peptides and hyperphosphorylated tau, respectively. Although accumulation of toxic Aβ species in the brain has been proposed as one of the important early events in AD, continued lack of success of clinical trials based on Aβ-targeting drugs has triggered the field to seek out alternative disease mechanisms and related therapeutic strategies. One of the new approaches is to uncover novel roles of pathological tau during disease progression. This review will primarily focus on recent advances in understanding the contributions of tau to AD.
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Affiliation(s)
- Nima N Naseri
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, USA.
| | - Hong Wang
- Eli Lilly and Company, Lilly Corporate Center, Indianapolis, USA
| | - Jennifer Guo
- The University of North Carolina at Chapel Hill, Chapel Hill, USA
| | - Manu Sharma
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, USA
| | - Wenjie Luo
- Helen and Robert Appel Alzheimer's Disease Research Institute, Brain and Mind Research Institute, Weill Cornell Medicine, New York, USA.
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16
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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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17
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Ameen-Ali KE, Simpson JE, Wharton SB, Heath PR, Sharp PS, Brezzo G, Berwick J. The Time Course of Recognition Memory Impairment and Glial Pathology in the hAPP-J20 Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 2019; 68:609-624. [DOI: 10.3233/jad-181238] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Kamar E. Ameen-Ali
- Department of Psychology, University of Sheffield, Sheffield, UK
- Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle-Upon-Tyne, UK
| | - Julie E. Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Stephen B. Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul R. Heath
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Paul S. Sharp
- Department of Psychology, University of Sheffield, Sheffield, UK
| | - Gaia Brezzo
- Department of Psychology, University of Sheffield, Sheffield, UK
| | - Jason Berwick
- Department of Psychology, University of Sheffield, Sheffield, UK
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18
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Mateus JC, Lopes CDF, Cerquido M, Leitão L, Leitão D, Cardoso S, Ventura J, Aguiar P. Improved in vitro electrophysiology using 3D-structured microelectrode arrays with a micro-mushrooms islets architecture capable of promoting topotaxis. J Neural Eng 2019; 16:036012. [PMID: 30818300 DOI: 10.1088/1741-2552/ab0b86] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- José C Mateus
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, R. Alfredo Allen, 4200-135 Porto, Portugal. i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, R. Alfredo Allen, 4200-135 Porto, Portugal. Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge de Viterbo Ferreira, 4050-313 Porto, Portugal
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19
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Govaerts K, Lechat B, Struys T, Kremer A, Borghgraef P, Van Leuven F, Himmelreich U, Dresselaers T. Longitudinal assessment of cerebral perfusion and vascular response to hypoventilation in a bigenic mouse model of Alzheimer's disease with amyloid and tau pathology. NMR IN BIOMEDICINE 2019; 32:e4037. [PMID: 30489666 DOI: 10.1002/nbm.4037] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 06/09/2023]
Abstract
Alzheimer's disease is the most common neurodegenerative disease, and many patients also present with vascular dysfunction. In this study, we aimed to assess cerebral blood flow (CBF) and cerebrovascular response (CVR) as early, pre-symptomatic (3 months of age), imaging markers in a bigenic model of Alzheimer's disease (APP.V717IxTau.P301L, biAT) and in the monogenic parental strains. We further developed our previously published combination of pulsed arterial spin labeling perfusion MRI and hypo-ventilation paradigm, which allows weaning of the mice from the ventilator. Furthermore, the commonly used isoflurane anesthesia induces vasodilation and is thereby inherently a vascular challenge. We therefore assessed perfusion differences in the mouse models under free-breathing isoflurane conditions. We report (i) that we can determine CBF and hypoventilation-based CVR under ketamine/midazolam anesthesia and wean mice from the ventilator, making it a valuable tool for assessment of CBF and CVR in mice, (ii) that biAT mice exhibit lower cortical CBF than wild-type mice at age 3 months, (iii) that CVR was increased in both biAT and APP.V717I mice but not in Tau.P301L mice, identifying the APP genotype as a strong influencer of brain CVR and (iv) that perfusion differences at baseline are masked by the widely used isoflurane anesthesia.
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Affiliation(s)
- Kristof Govaerts
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Benoit Lechat
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Tom Struys
- Morphology Research Group, Biomedical Research Institute, Universiteit Hasselt, Hasselt, Belgium
| | - Anna Kremer
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Peter Borghgraef
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Fred Van Leuven
- LEGTEGG, Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Uwe Himmelreich
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
| | - Tom Dresselaers
- Biomedical MRI/MoSAIC, Department of Imaging and Pathology, KU Leuven, Leuven, Belgium
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20
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Early alterations in hippocampal perisomatic GABAergic synapses and network oscillations in a mouse model of Alzheimer's disease amyloidosis. PLoS One 2019; 14:e0209228. [PMID: 30645585 PMCID: PMC6333398 DOI: 10.1371/journal.pone.0209228] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/30/2018] [Indexed: 01/01/2023] Open
Abstract
Several lines of evidence imply changes in inhibitory interneuron connectivity and subsequent alterations in oscillatory network activities in the pathogenesis of Alzheimer’s Disease (AD). Recently, we provided evidence for an increased immunoreactivity of both the postsynaptic scaffold protein gephyrin and the GABAA receptor γ2-subunit in the hippocampus of young (1 and 3 months of age), APPPS1 mice. These mice represent a well-established model of cerebral amyloidosis, which is a hallmark of human AD. In this study, we demonstrate a robust increase of parvalbumin immunoreactivity and accentuated projections of parvalbumin positive (PV+) interneurons, which target perisomatic regions of pyramidal cells within the hippocampal subregions CA1 and CA3 of 3-month-old APPPS1 mice. Colocalisation studies confirmed a significant increase in the density of PV+ projections labeled with antibodies against a presynaptic (vesicular GABA transporter) and a postsynaptic marker (gephyrin) of inhibitory synapses within the pyramidal cell layer of CA1 and CA3. As perisomatic inhibition by PV+-interneurons is crucial for the generation of hippocampal network oscillations involved in spatial processing, learning and memory formation we investigated the impact of the putative enhanced perisomatic inhibition on two types of fast neuronal network oscillations in acute hippocampal slices: 1. spontaneously occurring sharp wave-ripple complexes (SPW-R), and 2. cholinergic γ-oscillations. Interestingly, both network patterns were generally preserved in APPPS1 mice similar to WT mice. However, the comparison of simultaneous CA3 and CA1 recordings revealed that the incidence and amplitude of SPW-Rs were significantly lower in CA1 vs CA3 in APPPS1 slices, whereas the power of γ-oscillations was significantly higher in CA3 vs CA1 in WT-slices indicating an impaired communication between the CA3 and CA1 network activities in APPPS1 mice. Taken together, our data demonstrate an increased GABAergic synaptic output of PV+ interneurons impinging on pyramidal cells of CA1 and CA3, which might limit the coordinated cross-talk between these two hippocampal areas in young APPPS1 mice and mediate long-term changes in synaptic inhibition during progression of amyloidosis.
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Abstract
The brain is the most complex organ of the body, and many pathological processes underlying various brain disorders are poorly understood. Limited accessibility hinders observation of such processes in the in vivo brain, and experimental freedom is often insufficient to enable informative manipulations. In vitro preparations (brain slices or cultures of dissociated neurons) offer much better accessibility and reduced complexity and have yielded valuable new insights into various brain disorders. Both types of preparations have their advantages and limitations with regard to lifespan, preservation of in vivo brain structure, composition of cell types, and the link to behavioral outcome is often unclear in in vitro models. While these limitations hamper general usage of in vitro preparations to study, e.g., brain development, in vitro preparations are very useful to study neuronal and synaptic functioning under pathologic conditions. This chapter addresses several brain disorders, focusing on neuronal and synaptic functioning, as well as network aspects. Recent progress in the fields of brain circulation disorders, excitability disorders, and memory disorders will be discussed, as well as limitations of current in vitro models.
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22
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Alkadhi KA. Delayed effects of combined stress and Aβ infusion on L-LTP of the dentate gyrus: Prevention by nicotine. Neurosci Lett 2018; 682:10-15. [PMID: 29883681 DOI: 10.1016/j.neulet.2018.05.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 05/15/2018] [Accepted: 05/25/2018] [Indexed: 11/16/2022]
Abstract
Alzheimer's Disease (AD) is a progressive dementia hallmarked by the presence in the brain of extracellular beta-amyloid (Aβ) plaques and intraneuronal fibrillary tangles. Chronic stress is associated with heightened Aβ buildup and acceleration of development of AD, however, stress alone has no significant effect on synaptic plasticity in the dentate gyrus (DG) area. Previously, we have reported that the combination of stress and AD causes more severe inhibition of synaptic plasticity of hippocampal area CA1 than chronic stress or AD alone, and that chronic nicotine treatment prevents this impairment. To investigate the effect of stress and nicotine on synaptic plasticity in the relatively injury-resistant DG area, the present experiments analyzed the effect of chronic stress and the neuroprotective effect of nicotine on LTP in the DG area of a rat model of AD. Wistar rats were chronically stressed and treated with nicotine (1 mg/kg/twice daily; s.c.) for six weeks. Then, at weeks 5-6, AD model was generated by 14-day i.c.v osmotic pump infusion of Aβ peptides (300 pmol/day) into the brains of these rats. Field potential recordings from the DG area of anesthetized rats, revealed that while chronic stress did not accentuate Aβ-induced impairments of E-LTP, it markedly augmented Aβ effect on L-LTP that was only seen 100 min after multiple high frequency stimulation. This delayed action is likely to be due to impairment of process of de novo protein synthesis required for maintenance phase of L-LTP. Chronic nicotine treatment prevented stress-enhanced suppression of synaptic plasticity.
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Affiliation(s)
- Karim A Alkadhi
- Department of Pharmacological and Pharmaceutical Sciences, College of Pharmacy, University of Houston, Houston, TX, 77204, USA.
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23
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Tau Internalization is Regulated by 6-O Sulfation on Heparan Sulfate Proteoglycans (HSPGs). Sci Rep 2018; 8:6382. [PMID: 29686391 PMCID: PMC5913225 DOI: 10.1038/s41598-018-24904-z] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Accepted: 03/28/2018] [Indexed: 12/12/2022] Open
Abstract
The misfolding and accumulation of tau protein into intracellular aggregates known as neurofibrillary tangles is a pathological hallmark of neurodegenerative diseases such as Alzheimer’s disease. However, while tau propagation is a known marker for disease progression, exactly how tau propagates from one cell to another and what mechanisms govern this spread are still unclear. Here, we report that cellular internalization of tau is regulated by quaternary structure and have developed a cellular assay to screen for genetic modulators of tau uptake. Using CRISPRi technology we have tested 3200 genes for their ability to regulate tau entry and identified enzymes in the heparan sulfate proteoglycan biosynthetic pathway as key regulators. We show that 6-O-sulfation is critical for tau-heparan sulfate interactions and that this modification regulates uptake in human central nervous system cell lines, iPS-derived neurons, and mouse brain slice culture. Together, these results suggest novel strategies to halt tau transmission.
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24
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An S, Zhao YF, Lü XY, Wang ZG. Quantitative evaluation of extrinsic factors influencing electrical excitability in neuronal networks: Voltage Threshold Measurement Method (VTMM). Neural Regen Res 2018; 13:1026-1035. [PMID: 29926830 PMCID: PMC6022462 DOI: 10.4103/1673-5374.233446] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The electrical excitability of neural networks is influenced by different environmental factors. Effective and simple methods are required to objectively and quantitatively evaluate the influence of such factors, including variations in temperature and pharmaceutical dosage. The aim of this paper was to introduce ‘the voltage threshold measurement method’, which is a new method using microelectrode arrays that can quantitatively evaluate the influence of different factors on the electrical excitability of neural networks. We sought to verify the feasibility and efficacy of the method by studying the effects of acetylcholine, ethanol, and temperature on hippocampal neuronal networks and hippocampal brain slices. First, we determined the voltage of the stimulation pulse signal that elicited action potentials in the two types of neural networks under normal conditions. Second, we obtained the voltage thresholds for the two types of neural networks under different concentrations of acetylcholine, ethanol, and different temperatures. Finally, we obtained the relationship between voltage threshold and the three influential factors. Our results indicated that the normal voltage thresholds of the hippocampal neuronal network and hippocampal slice preparation were 56 and 31 mV, respectively. The voltage thresholds of the two types of neural networks were inversely proportional to acetylcholine concentration, and had an exponential dependency on ethanol concentration. The curves of the voltage threshold and the temperature of the medium for the two types of neural networks were U-shaped. The hippocampal neuronal network and hippocampal slice preparations lost their excitability when the temperature of the medium decreased below 34 and 33°C or increased above 42 and 43°C, respectively. These results demonstrate that the voltage threshold measurement method is effective and simple for examining the performance/excitability of neuronal networks.
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Affiliation(s)
- Shuai An
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu Province, China
| | - Yong-Fang Zhao
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing, Jiangsu Province, China
| | - Xiao-Ying Lü
- State Key Laboratory of Bioelectronics, Southeast University, Nanjing; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
| | - Zhi-Gong Wang
- Institute of RF- & OE-ICs, Southeast University, Nanjing; Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu Province, China
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25
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Sidoryk-Wegrzynowicz M, Gerber YN, Ries M, Sastre M, Tolkovsky AM, Spillantini MG. Astrocytes in mouse models of tauopathies acquire early deficits and lose neurosupportive functions. Acta Neuropathol Commun 2017; 5:89. [PMID: 29187256 PMCID: PMC6389177 DOI: 10.1186/s40478-017-0478-9] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 10/02/2017] [Indexed: 01/17/2023] Open
Abstract
Microtubule-associated protein tau aggregates constitute the characteristic neuropathological features of several neurodegenerative diseases grouped under the name of tauopathies. It is now clear that the process of tau aggregation is associated with neurodegeneration. Several transgenic tau mouse models have been developed where tau progressively aggregates, causing neuronal death. Previously we have shown that transplantation of astrocytes in P301S tau transgenic mice rescues cortical neuron death, implying that the endogenous astrocytes are deficient in survival support. We now show that the gliosis markers Glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100β) are elevated in brains from P301S tau mice compared to control C57Bl/6 mice whereas the expression of proteins involved in glutamine/glutamate metabolism are reduced, pointing to a functional deficit. To test whether astrocytes from P301S mice are intrinsically deficient, we co-cultured astrocytes and neurons from control and P301S mice. Significantly more C57-derived and P301S-derived neurons survived when cells were cultured with C57-derived astrocytes or astrocyte conditioned medium (C57ACM) than with P301S-derived astrocytes or astrocyte conditioned medium (P301SACM), or ACM from P301L tau mice, where the transgene is also specifically expressed in neurons. The astrocytic alterations developed in mice during the first postnatal week of life. In addition, P301SACM significantly decreased presynaptic (synaptophysin, SNP) and postsynaptic (postsynaptic density protein 95, PSD95) protein expression in cortical neuron cultures whereas C57ACM enhanced these markers. Since thrombospondin 1 (TSP-1) is a major survival and synaptogenic factor, we examined whether TSP-1 is deficient in P301S mouse brains and ACM. Significantly less TSP-1 was expressed in the brains of P301S tau mice or produced by P301S-derived astrocytes, whereas supplementation of P301SACM with TSP-1 increased its neurosupportive capacity. Our results demonstrate that P301S-derived astrocytes acquire an early functional deficiency that may explain in part the loss of cortical neurons in the P301S tau mice.
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Getz AM, Xu F, Visser F, Persson R, Syed NI. Tumor suppressor menin is required for subunit-specific nAChR α5 transcription and nAChR-dependent presynaptic facilitation in cultured mouse hippocampal neurons. Sci Rep 2017; 7:1768. [PMID: 28496137 PMCID: PMC5432004 DOI: 10.1038/s41598-017-01825-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 04/04/2017] [Indexed: 01/14/2023] Open
Abstract
In the central nervous system (CNS), cholinergic transmission induces synaptic plasticity that is required for learning and memory. However, our understanding of the development and maintenance of cholinergic circuits is limited, as the factors regulating the expression and clustering of neuronal nicotinic acetylcholine receptors (nAChRs) remain poorly defined. Recent studies from our group have implicated calpain-dependent proteolytic fragments of menin, the product of the MEN1 tumor suppressor gene, in coordinating the transcription and synaptic clustering of nAChRs in invertebrate central neurons. Here, we sought to determine whether an analogous cholinergic mechanism underlies menin's synaptogenic function in the vertebrate CNS. Our data from mouse primary hippocampal cultures demonstrate that menin and its calpain-dependent C-terminal fragment (C-menin) regulate the subunit-specific transcription and synaptic clustering of neuronal nAChRs, respectively. MEN1 knockdown decreased nAChR α5 subunit expression, the clustering of α7 subunit-containing nAChRs at glutamatergic presynaptic terminals, and nicotine-induced presynaptic facilitation. Moreover, the number and function of glutamatergic synapses was unaffected by MEN1 knockdown, indicating that the synaptogenic actions of menin are specific to cholinergic regulation. Taken together, our results suggest that the influence of menin on synapse formation and synaptic plasticity occur via modulation of nAChR channel subunit composition and functional clustering.
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Affiliation(s)
- Angela M Getz
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Department of Neuroscience, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | - Fenglian Xu
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
- Department of Biology, Saint Louis University, Saint Louis, Missouri, 63103, USA
| | - Frank Visser
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, T2N 1N4, Canada
| | | | - Naweed I Syed
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, T2N 1N4, Canada.
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Du ZJ, Kolarcik CL, Kozai TDY, Luebben SD, Sapp SA, Zheng XS, Nabity JA, Cui XT. Ultrasoft microwire neural electrodes improve chronic tissue integration. Acta Biomater 2017; 53:46-58. [PMID: 28185910 DOI: 10.1016/j.actbio.2017.02.010] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 02/02/2017] [Accepted: 02/05/2017] [Indexed: 12/11/2022]
Abstract
Chronically implanted neural multi-electrode arrays (MEA) are an essential technology for recording electrical signals from neurons and/or modulating neural activity through stimulation. However, current MEAs, regardless of the type, elicit an inflammatory response that ultimately leads to device failure. Traditionally, rigid materials like tungsten and silicon have been employed to interface with the relatively soft neural tissue. The large stiffness mismatch is thought to exacerbate the inflammatory response. In order to minimize the disparity between the device and the brain, we fabricated novel ultrasoft electrodes consisting of elastomers and conducting polymers with mechanical properties much more similar to those of brain tissue than previous neural implants. In this study, these ultrasoft microelectrodes were inserted and released using a stainless steel shuttle with polyethyleneglycol (PEG) glue. The implanted microwires showed functionality in acute neural stimulation. When implanted for 1 or 8weeks, the novel soft implants demonstrated significantly reduced inflammatory tissue response at week 8 compared to tungsten wires of similar dimension and surface chemistry. Furthermore, a higher degree of cell body distortion was found next to the tungsten implants compared to the polymer implants. Our results support the use of these novel ultrasoft electrodes for long term neural implants. STATEMENT OF SIGNIFICANCE One critical challenge to the translation of neural recording/stimulation electrode technology to clinically viable devices for brain computer interface (BCI) or deep brain stimulation (DBS) applications is the chronic degradation of device performance due to the inflammatory tissue reaction. While many hypothesize that soft and flexible devices elicit reduced inflammatory tissue responses, there has yet to be a rigorous comparison between soft and stiff implants. We have developed an ultra-soft microelectrode with Young's modulus lower than 1MPa, closely mimicking the brain tissue modulus. Here, we present a rigorous histological comparison of this novel ultrasoft electrode and conventional stiff electrode with the same size, shape and surface chemistry, implanted in rat brains for 1-week and 8-weeks. Significant improvement was observed for ultrasoft electrodes, including inflammatory tissue reaction, electrode-tissue integration as well as mechanical disturbance to nearby neurons. A full spectrum of new techniques were developed in this study, from insertion shuttle to in situ sectioning of the microelectrode to automated cell shape analysis, all of which should contribute new methods to the field. Finally, we showed the electrical functionality of the ultrasoft electrode, demonstrating the potential of flexible neural implant devices for future research and clinical use.
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Affiliation(s)
- Zhanhong Jeff Du
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Shenzhen Key Lab of Neuropsychiatric Modulation, CAS Center for Excellence in Brain Science, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Christi L Kolarcik
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; Systems Neuroscience Institute, University of Pittsburgh, PA, USA
| | - Takashi D Y Kozai
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA; NeuroTech Center of Brain Institute, University of Pittsburgh, PA, USA
| | | | | | - Xin Sally Zheng
- Department of Bioengineering, University of Pittsburgh, PA, USA
| | - James A Nabity
- Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO,USA
| | - X Tracy Cui
- Department of Bioengineering, University of Pittsburgh, PA, USA; Center for the Neural Basis of Cognition, University of Pittsburgh, PA, USA; McGowan Institute for Regenerative Medicine, University of Pittsburgh, PA, USA.
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Andalibi V, Aaltonen T, Christophe F, Mikkonen T. SiMEA: a framework for simulating neurons on multi-electrode array. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2016:5965-5968. [PMID: 28269611 DOI: 10.1109/embc.2016.7592087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A Multi-Electrode Array (MEA) is a practical device for recording the extracellular activity of in-vitro biological culture. Such culture - for instance neurons - is prone to mistakes leading to irrelevant recordings or no recording at all. Additionally, with the expenses generated by in-vitro culture, minimizing risks is a must. This paper proposes a framework designed and implemented for simulating the spatial positioning of neuronal cultures on a MEA. The framework serves as a sandbox for researchers to simulate the model of their MEA experiments before its eventual in-vitro implementation. The framework enables simulating the density of the plated culture, the death of cells over time, choosing diverse reconstructed morphologies of cells, and simulating their spiking activity in interaction with Brian2 simulator.
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Crescenzi R, DeBrosse C, Nanga RP, Byrne MD, Krishnamoorthy G, D’Aquilla K, Nath H, Morales KH, Iba M, Hariharan H, Lee VM, Detre JA, Reddy R. Longitudinal imaging reveals subhippocampal dynamics in glutamate levels associated with histopathologic events in a mouse model of tauopathy and healthy mice. Hippocampus 2017; 27:285-302. [PMID: 27997993 PMCID: PMC5396955 DOI: 10.1002/hipo.22693] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 12/02/2016] [Accepted: 12/02/2016] [Indexed: 11/08/2022]
Abstract
Tauopathies are neurodegenerative disorders characterized by abnormal intracellular aggregates of tau protein, and include Alzheimer's disease, corticobasal degeneration, frontotemporal dementia, and traumatic brain injury. Glutamate metabolism is altered in neurodegenerative disorders manifesting in higher or lower concentrations of glutamate, its transporters or receptors. Previously, glutamate chemical exchange saturation transfer (GluCEST) magnetic resonance imaging (MRI) demonstrated that glutamate levels are reduced in regions of synapse loss in the hippocampus of a mouse model of late-stage tauopathy. We performed a longitudinal GluCEST imaging experiment paired with a cross-sectional study of histologic markers of tauopathy to determine whether (1) early GluCEST changes are associated with synapse loss before volume loss occurs in the hippocampus, and whether (2) subhippocampal dynamics in GluCEST are associated with histopathologic events related to glutamate alterations in tauopathy. Live imaging of the hippocampus in three serial slices was performed without exogenous contrast agents, and subregions were segmented based on a k-means cluster model. Subregions of the hippocampus were analyzed (cornu ammonis CA1, CA3, dentate gyrus DG, and ventricle) in order to associate local MRI-observable changes in glutamate with histological measures of glial cell proliferation (GFAP), synapse density (synaptophysin, VGlut1) and glutamate receptor (NMDA-NR1) levels. Early differences in GluCEST between healthy and tauopathy mice were measured in the CA1 and DG subregions (30% reduction, P ≤ 0.001). Synapse density was also significantly reduced in every subregion of the hippocampus in tauopathy mice by 6 months. Volume was not significantly reduced in any subregion until 13 months. Further, a gradient in glutamate levels was observed in vivo along hippocampal axes that became polarized as tauopathy progressed. Dynamics in hippocampal glutamate levels throughout lifetime were most closely correlated with combined changes in synaptophysin and GFAP, indicating that GluCEST imaging may be a surrogate marker of glutamate concentration in glial cells and at the synaptic level. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Rachelle Crescenzi
- Department of Biochemistry & Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Catherine DeBrosse
- Department of Biochemistry & Molecular Biophysics (BMB), University of Pennsylvania, Philadelphia, PA, USA
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Ravi P.R. Nanga
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew D. Byrne
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - Guruprasad Krishnamoorthy
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Kevin D’Aquilla
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Nath
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Knashawn H. Morales
- Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Michiyo Iba
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - Hari Hariharan
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
| | - Virginia M.Y Lee
- Center for Neurodegenerative Disease Research (CNDR), University of Pennsylvania, Philadelphia, PA, USA
| | - John A. Detre
- Center for Functional Neuroimaging (CfN), University of Pennsylvania, Philadelphia, PA, USA
| | - Ravinder Reddy
- Center for Magnetic Resonance and Optical Imaging (CMROI), University of Pennsylvania, Philadelphia, PA, USA
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The "curved lead pathway" method to enable a single lead to reach any two intracranial targets. Sci Rep 2017; 7:40533. [PMID: 28074898 PMCID: PMC5225435 DOI: 10.1038/srep40533] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 12/07/2016] [Indexed: 12/23/2022] Open
Abstract
Deep brain stimulation is an effective way to treat movement disorders, and a powerful research tool for exploring brain functions. This report proposes a “curved lead pathway” method for lead implantation, such that a single lead can reach in sequence to any two intracranial targets. A new type of stereotaxic system for implanting a curved lead to the brain of human/primates was designed, the auxiliary device needed for this method to be used in rat/mouse was fabricated and verified in rat, and the Excel algorithm used for automatically calculating the necessary parameters was implemented. This “curved lead pathway” method of lead implantation may complement the current method, make lead implantation for multiple targets more convenient, and expand the experimental techniques of brain function research.
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Shaban H, O’Connor R, Ovsepian SV, Dinan TG, Cryan JF, Schellekens H. Electrophysiological approaches to unravel the neurobiological basis of appetite and satiety: use of the multielectrode array as a screening strategy. Drug Discov Today 2017; 22:31-42. [DOI: 10.1016/j.drudis.2016.09.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/03/2016] [Accepted: 09/06/2016] [Indexed: 01/10/2023]
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Kim HB, Oh TI, Swanberg KM, Lee MB, Kim TW, Woo EJ, Park JH, Kwon OI. Microelectrode array analysis of hippocampal network dynamics following theta-burst stimulation via current source density reconstruction by Gaussian interpolation. J Neurosci Methods 2016; 264:1-10. [PMID: 26880160 DOI: 10.1016/j.jneumeth.2016.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 02/05/2016] [Accepted: 02/06/2016] [Indexed: 10/22/2022]
Abstract
BACKGROUND Multielectrode arrays (MEAs) have been used to understand electrophysiological network dynamics by recording real-time activity in groups of cells. The extent to which the collection of such data enables hypothesis testing on the level of circuits and networks depends largely on the sophistication of the analyses applied. NEW METHOD We studied the systemic temporal variations of endogenous signaling within an organotypic hippocampal network following theta-burst stimulation (TBS) to the Schaffer collateral-commissural pathways. The recovered current source density (CSD) information from the raw grid of extracellular potentials by using a Gaussian interpolation method increases spatial resolution and avoids border artifacts by numerical differentials. RESULTS We compared total sink and source currents in DG, CA3, and CA1; calculated accumulated correlation coefficients to compare pre- with post-stimulation CSD dynamics in each region; and reconstructed functional connectivity maps for regional cross-correlations with respect to temporal CSD variations. The functional connectivity maps for potential correlations pre- and post-TBS were compared to investigate the neural network as a whole, revealing differences post-TBS. COMPARISON WITH EXISTING METHOD(S) Previous MEA work on plasticity in hippocampal evoked potentials has focused on synchronicity across the hippocampus within isolated subregions. Such analyses ignore the complex relationships among diverse components of the hippocampal circuitry, thus failing to capture network-level behaviors integral to understanding hippocampal function. CONCLUSIONS The proposed method of recovering current source density to examine whole-hippocampal function is sensitive to experimental manipulation and is worth further examination in the context of network-level analyses of neural signaling.
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Affiliation(s)
- Hyun-Bum Kim
- Department of East-West Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Republic of Korea
| | - Tong-In Oh
- Department of Biomedical Engineering, Engineering, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
| | - Kelley M Swanberg
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Republic of Korea
| | - Mun-Bae Lee
- Department of Mathematics, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul 143-701, Republic of Korea
| | - Tae-Woo Kim
- Department of East-West Medical Science, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Republic of Korea
| | - Eung-Je Woo
- Department of Biomedical Engineering, Engineering, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 130-701, Republic of Korea
| | - Ji-Ho Park
- Department of East-West Medicine, Graduate School of East-West Medical Science, Kyung Hee University, Deogyeong-daero, Giheung-gu, Yongin 446-701, Republic of Korea
| | - Oh-In Kwon
- Department of Mathematics, Konkuk University, Neungdong-ro, Gwangjin-gu, Seoul 143-701, Republic of Korea.
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Maeda S, Djukic B, Taneja P, Yu GQ, Lo I, Davis A, Craft R, Guo W, Wang X, Kim D, Ponnusamy R, Gill TM, Masliah E, Mucke L. Expression of A152T human tau causes age-dependent neuronal dysfunction and loss in transgenic mice. EMBO Rep 2016; 17:530-51. [PMID: 26931567 PMCID: PMC4818780 DOI: 10.15252/embr.201541438] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 01/13/2016] [Indexed: 11/24/2022] Open
Abstract
A152T‐variant human tau (hTau‐A152T) increases risk for tauopathies, including Alzheimer's disease. Comparing mice with regulatable expression of hTau‐A152T or wild‐type hTau (hTau‐WT), we find age‐dependent neuronal loss, cognitive impairments, and spontaneous nonconvulsive epileptiform activity primarily in hTau‐A152T mice. However, overexpression of either hTau species enhances neuronal responses to electrical stimulation of synaptic inputs and to an epileptogenic chemical. hTau‐A152T mice have higher hTau protein/mRNA ratios in brain, suggesting that A152T increases production or decreases clearance of hTau protein. Despite their functional abnormalities, aging hTau‐A152T mice show no evidence for accumulation of insoluble tau aggregates, suggesting that their dysfunctions are caused by soluble tau. In human amyloid precursor protein (hAPP) transgenic mice, co‐expression of hTau‐A152T enhances risk of early death and epileptic activity, suggesting copathogenic interactions between hTau‐A152T and amyloid‐β peptides or other hAPP metabolites. Thus, the A152T substitution may augment risk for neurodegenerative diseases by increasing hTau protein levels, promoting network hyperexcitability, and synergizing with the adverse effects of other pathogenic factors.
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Affiliation(s)
- Sumihiro Maeda
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Biljana Djukic
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Praveen Taneja
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Iris Lo
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Allyson Davis
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Ryan Craft
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Weikun Guo
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Xin Wang
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Daniel Kim
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | | | - T Michael Gill
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California, San Diego, La Jolla, CA, USA Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, San Francisco, CA, USA Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
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Astrogliosis: An integral player in the pathogenesis of Alzheimer's disease. Prog Neurobiol 2016; 144:121-41. [PMID: 26797041 DOI: 10.1016/j.pneurobio.2016.01.001] [Citation(s) in RCA: 186] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 11/10/2015] [Accepted: 01/10/2016] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease is the main cause of dementia in the elderly and begins with a subtle decline in episodic memory followed by a more general decline in overall cognitive abilities. Though the exact trigger for this cascade of events remains unknown the presence of the misfolded amyloid-beta protein triggers reactive gliosis, a prominent neuropathological feature in the brains of Alzheimer's patients. The cytoskeletal and morphological changes of astrogliosis are its evident features, while changes in oxidative stress defense, cholesterol metabolism, and gene transcription programs are less manifest. However, these latter molecular changes may underlie a disruption in homeostatic regulation that keeps the brain environment balanced. Astrocytes in Alzheimer's disease show changes in glutamate and GABA signaling and recycling, potassium buffering, and in cholinergic, purinergic, and calcium signaling. Ultimately the dysregulation of homeostasis maintained by astrocytes can have grave consequences for the stability of microcircuits within key brain regions. Specifically, altered inhibition influenced by astrocytes can lead to local circuit imbalance with farther reaching consequences for the functioning of larger neuronal networks. Healthy astrocytes have a role in maintaining and modulating normal neuronal communication, synaptic physiology and energy metabolism, astrogliosis interferes with these functions. This review considers the molecular and functional changes occurring during astrogliosis in Alzheimer's disease, and proposes that astrocytes are key players in the development of dementia.
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CERQUERA EA, MUÑOZ J, ARAYA J, GÓMEZ O. REGISTRO DE ACTIVIDAD ELÉCTRICA EN LA RETINA DE UNA RATA ALBINA EMPLEANDO UNA MATRIZ DE MICROELECTRODOS. ACTA BIOLÓGICA COLOMBIANA 2015. [DOI: 10.15446/abc.v20n3.46216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
<p>Las matrices de microelectrodos son dispositivos que permiten la detección de potenciales de acción o espigas en poblaciones de células excitables, ofreciendo varias aplicaciones en el campo de las neurociencias y la biología. Este trabajo muestra un protocolo para el registro de espigas en una población de células ganglionares retinales empleando una matriz de microelectrodos. La retina de una rata albina fue extraída y preparada para ser estimulada <em>in vitro </em>con luz led blanca, con el fin de registrar sus espigas evocadas ante estos estímulos. Cada microelectrodo puede registrar espigas de más de una célula ganglionar, razón por la cual se determinó a qué célula pertenece cada espiga aplicando un procedimiento conocido como “clasificación de espigas”. El trabajo permitió obtener el registro de un periodo de estimulación y otro de no estimulación, con el fin de representar los potenciales de acción evocados con luz y los espontáneos. Los registros fueron almacenados para visualizar las espigas de las células ganglionares y poder aplicar la herramienta de clasificación de espigas. De este modo, se almacenan los instantes de tiempo en los cuales cada célula ganglionar registrada generó potenciales de acción. Este trabajo conllevó al establecimiento de un protocolo de experimentación básico enfocado al uso de matrices MEA en el laboratorio de adquisición de potenciales extracelulares de la Universidad Antonio Nariño Sede Bogotá, no sólo para caracterizar los potenciales de acción de células ganglionares retinales, sino también para otro tipo de células que puedan ser estudiadas empleando matrices de microelectrodos.</p><p align="center"><strong>Recording of Electrical Activity in the Retina of an Albino Rat Employing a Microelectrode Array</strong></p><p>The microelectrode arrays (MEA) are devices that allow the detection of action potentials or spikes in populations of excitable cells, offering a wide spectrum of applications in topics of Neurosciences and Biology. This work describes a protocol for recording of spikes in a population of retinal ganglion cells employing a microelectrode array. The retina of an albino rat was dissected and prepared to be stimulated<em> in vitro </em>with white led light and to record their evoked spikes. Each microelectrode can record spikes from more than a ganglion cell, for which it was necessary to determine which cell fires each spike applying a procedure known as spike sorting. The work allowed to obtain the recording of a stimulation period and another of non-stimulation, representing evoked and spontaneous action potentials. The recordings were saved, in order to visualize the action potentials of the ganglion cells detected and to apply a computational method for the spike sorting. In this way, it was saved the time stamps in which each action potential was fired by its respective cell. This work established a basic experimentation protocol focused to the use of MEA devices in the laboratory for acquisition of extracellular potentials at the Antonio Nariño University – Bogota Headquarters, not only for characterization of action potentials fired by retinal ganglion cells populations, but also for other kind of cells that can be studied employing MEA devices.</p><p> </p>
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Dujardin S, Colin M, Buée L. Invited review: Animal models of tauopathies and their implications for research/translation into the clinic. Neuropathol Appl Neurobiol 2015; 41:59-80. [DOI: 10.1111/nan.12200] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/23/2014] [Indexed: 02/01/2023]
Affiliation(s)
- Simon Dujardin
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
| | - Morvane Colin
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
| | - Luc Buée
- Inserm, UMR1172 Jean-Pierre Aubert Research Centre; Lille France
- Faculté de Médecine; Université de Lille; France
- Memory Clinic; CHRU; Lille France
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Pooters T, Van der Jeugd A, Callaerts-Vegh Z, D'Hooge R. Telencephalic neurocircuitry and synaptic plasticity in rodent spatial learning and memory. Brain Res 2015; 1621:294-308. [PMID: 25619550 DOI: 10.1016/j.brainres.2015.01.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 01/14/2023]
Abstract
Spatial learning and memory in rodents represent close equivalents of human episodic declarative memory, which is especially sensitive to cerebral aging, neurodegeneration, and various neuropsychiatric disorders. Many tests and protocols are available for use in laboratory rodents, but Morris water maze and radial-arm maze remain the most widely used as well as the most valid and reliable spatial tests. Telencephalic neurocircuitry that plays functional roles in spatial learning and memory includes hippocampus, dorsal striatum and medial prefrontal cortex. Prefrontal-hippocampal circuitry comprises the major associative system in the rodent brain, and is critical for navigation in physical space, whereas interconnections between prefrontal cortex and dorsal striatum are probably more important for motivational or goal-directed aspects of spatial learning. Two major forms of synaptic plasticity, namely long-term potentiation, a lasting increase in synaptic strength between simultaneously activated neurons, and long-term depression, a decrease in synaptic strength, have been found to occur in hippocampus, dorsal striatum and medial prefrontal cortex. These and other phenomena of synaptic plasticity are probably crucial for the involvement of telencephalic neurocircuitry in spatial learning and memory. They also seem to play a role in the pathophysiology of two brain pathologies with episodic declarative memory impairments as core symptoms, namely Alzheimer's disease and schizophrenia. Further research emphasis on rodent telencephalic neurocircuitry could be relevant to more valid and reliable preclinical research on these most devastating brain disorders. This article is part of a Special Issue entitled SI: Brain and Memory.
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Affiliation(s)
- Tine Pooters
- Laboratory of Biological Psychology, University of Leuven, Leuven, 102 Tiensestraat, BE-3000 Leuven, Belgium
| | - Ann Van der Jeugd
- Laboratory of Biological Psychology, University of Leuven, Leuven, 102 Tiensestraat, BE-3000 Leuven, Belgium
| | - Zsuzsanna Callaerts-Vegh
- Laboratory of Biological Psychology, University of Leuven, Leuven, 102 Tiensestraat, BE-3000 Leuven, Belgium
| | - Rudi D'Hooge
- Laboratory of Biological Psychology, University of Leuven, Leuven, 102 Tiensestraat, BE-3000 Leuven, Belgium.
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Tateno T, Nishikawa J. A CMOS IC-based multisite measuring system for stimulation and recording in neural preparations in vitro. FRONTIERS IN NEUROENGINEERING 2014; 7:39. [PMID: 25346683 PMCID: PMC4193337 DOI: 10.3389/fneng.2014.00039] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/15/2014] [Indexed: 11/13/2022]
Abstract
In this report, we describe the system integration of a complementary metal oxide semiconductor (CMOS) integrated circuit (IC) chip, capable of both stimulation and recording of neurons or neural tissues, to investigate electrical signal propagation within cellular networks in vitro. The overall system consisted of three major subunits: a 5.0 × 5.0 mm CMOS IC chip, a reconfigurable logic device (field-programmable gate array, FPGA), and a PC. To test the system, microelectrode arrays (MEAs) were used to extracellularly measure the activity of cultured rat cortical neurons and mouse cortical slices. The MEA had 64 bidirectional (stimulation and recording) electrodes. In addition, the CMOS IC chip was equipped with dedicated analog filters, amplification stages, and a stimulation buffer. Signals from the electrodes were sampled at 15.6 kHz with 16-bit resolution. The measured input-referred circuitry noise was 10.1 μ V root mean square (10 Hz to 100 kHz), which allowed reliable detection of neural signals ranging from several millivolts down to approximately 33 μ Vpp. Experiments were performed involving the stimulation of neurons with several spatiotemporal patterns and the recording of the triggered activity. An advantage over current MEAs, as demonstrated by our experiments, includes the ability to stimulate (voltage stimulation, 5-bit resolution) spatiotemporal patterns in arbitrary subsets of electrodes. Furthermore, the fast stimulation reset mechanism allowed us to record neuronal signals from a stimulating electrode around 3 ms after stimulation. We demonstrate that the system can be directly applied to, for example, auditory neural prostheses in conjunction with an acoustic sensor and a sound processing system.
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Affiliation(s)
- Takashi Tateno
- Special Research Promotion Group, Graduate School of Frontier Biosciences, Osaka University Osaka, Japan ; Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University Sapporo, Japan
| | - Jun Nishikawa
- Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University Sapporo, Japan
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Moderate Treadmill Exercise Protects Synaptic Plasticity of the Dentate Gyrus and Related Signaling Cascade in a Rat Model of Alzheimer's Disease. Mol Neurobiol 2014; 52:1067-1076. [PMID: 25288155 DOI: 10.1007/s12035-014-8916-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 09/28/2014] [Indexed: 12/23/2022]
Abstract
The dentate gyrus (DG) of the hippocampus is known to be more resistant to the effects of various external factors than other hippocampal areas. This study investigated the neuroprotective effects of moderate treadmill exercise on early-phase long-term potentiation (E-LTP) and its molecular signaling pathways in the DG of amyloid β rat model of sporadic Alzheimer's disease (AD). Animals were preconditioned to run on treadmill for 4 weeks and concurrently received ICV infusion of Aβ₁₋₄₂ peptides (250 pmol/day) during the third and fourth weeks of exercise training. We utilized in vivo electrophysiological recordings to assess the effect of exercise and/or AD pathology on basal synaptic transmission and E-LTP magnitude of the perforant pathway synapses in urethane-anesthetized rats. Immunoblotting analysis was used to quantify changes in the levels of learning and memory-related key signaling molecules. The AD-impaired basal synaptic transmission and suppression of E-LTP in the DG were prevented by prior moderate treadmill exercise. In addition, exercise normalized the basal levels of memory and E-LTP-related signaling molecules including Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), calcineurin (PP2B), and brain-derived neurotrophic factor (BDNF). Exercise also prevented the reduction of phosphorylated CaMKII and aberrant increase of PP2B seen after E-LTP induction in amyloid-infused rats. Our data suggests that by restoring the balance of kinase-phosphatase, 4 weeks of moderate treadmill exercise prevents DG synaptic deficits and deleterious alterations in signaling pathways associated with AD.
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Alldred MJ, Lee SH, Petkova E, Ginsberg SD. Expression profile analysis of hippocampal CA1 pyramidal neurons in aged Ts65Dn mice, a model of Down syndrome (DS) and Alzheimer's disease (AD). Brain Struct Funct 2014; 220:2983-96. [PMID: 25031177 DOI: 10.1007/s00429-014-0839-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 07/02/2014] [Indexed: 11/29/2022]
Abstract
Down syndrome (DS) is caused by the triplication of human chromosome 21 (HSA21) and is the most common genetic cause of intellectual disability, with individuals having deficits in cognitive function including hippocampal learning and memory and neurodegeneration of cholinergic basal forebrain neurons, a pathological hallmark of Alzheimer's disease (AD). To date, the molecular underpinnings driving this pathology have not been elucidated. The Ts65Dn mouse is a segmental trisomy model of DS and like DS/AD pathology, displays age-related cognitive dysfunction and basal forebrain cholinergic neuron (BFCN) degeneration. To determine molecular and cellular changes important for elucidating mechanisms of neurodegeneration in DS/AD pathology, expression profiling studies were performed. Molecular fingerprinting of homogeneous populations of Cornu Ammonis 1 (CA1) pyramidal neurons was performed via laser capture microdissection followed by Terminal Continuation RNA amplification combined with custom-designed microarray analysis and subsequent validation of individual transcripts by qPCR and protein analysis via immunoblotting. Significant alterations were observed within CA1 pyramidal neurons of aged Ts65Dn mice compared to normal disomic (2N) littermates, notably in excitatory and inhibitory neurotransmission receptor families and neurotrophins, including brain-derived neurotrophic factor as well as several cognate neurotrophin receptors. Examining gene and protein expression levels after the onset of BFCN degeneration elucidated transcriptional and translational changes in neurons within a vulnerable circuit that may cause the AD-like pathology seen in DS as these individuals age, and provide rational targets for therapeutic interventions.
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Affiliation(s)
- Melissa J Alldred
- Center for Dementia Research, Nathan Kline Institute, 140 Old Orangeburg Road, Orangeburg, NY, 10962, USA
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Hubin E, van Nuland NAJ, Broersen K, Pauwels K. Transient dynamics of Aβ contribute to toxicity in Alzheimer's disease. Cell Mol Life Sci 2014; 71:3507-21. [PMID: 24803005 PMCID: PMC4143600 DOI: 10.1007/s00018-014-1634-z] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 04/15/2014] [Accepted: 04/22/2014] [Indexed: 12/20/2022]
Abstract
The aggregation and deposition of the amyloid-β peptide (Aβ) in the brain has been linked with neuronal death, which progresses in the diagnostic and pathological signs of Alzheimer’s disease (AD). The transition of an unstructured monomeric peptide into self-assembled and more structured aggregates is the crucial conversion from what appears to be a harmless polypeptide into a malignant form that causes synaptotoxicity and neuronal cell death. Despite efforts to identify the toxic form of Aβ, the development of effective treatments for AD is still limited by the highly transient and dynamic nature of interconverting forms of Aβ. The variability within the in vivo “pool” of different Aβ peptides is another complicating factor. Here we review the dynamical interplay between various components that influence the heterogeneous Aβ system, from intramolecular Aβ flexibility to intermolecular dynamics between various Aβ alloforms and external factors. The complex dynamics of Aβ contributes to the causative role of Aβ in the pathogenesis of AD.
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Affiliation(s)
- E Hubin
- Nanobiophysics Group, MIRA Institute for Biomedical Technology and Technical Medicine, Faculty of Science and Technology, University of Twente, 7500 AE, Enschede, The Netherlands
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Early structural and functional defects in synapses and myelinated axons in stratum lacunosum moleculare in two preclinical models for tauopathy. PLoS One 2014; 9:e87605. [PMID: 24498342 PMCID: PMC3912020 DOI: 10.1371/journal.pone.0087605] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/21/2013] [Indexed: 02/04/2023] Open
Abstract
The stratum lacunosum moleculare (SLM) is the connection hub between entorhinal cortex and hippocampus, two brain regions that are most vulnerable in Alzheimer's disease. We recently identified a specific synaptic deficit of Nectin-3 in transgenic models for tauopathy. Here we defined cognitive impairment and electrophysiological problems in the SLM of Tau.P301L mice, which corroborated the structural defects in synapses and dendritic spines. Reduced diffusion of DiI from the ERC to the hippocampus indicated defective myelinated axonal pathways. Ultrastructurally, myelinated axons in the temporoammonic pathway (TA) that connects ERC to CA1 were damaged in Tau.P301L mice at young age. Unexpectedly, the myelin defects were even more severe in bigenic biGT mice that co-express GSK3β with Tau.P301L in neurons. Combined, our data demonstrate that neuronal expression of protein Tau profoundly affected the functional and structural organization of the entorhinal-hippocampal complex, in particular synapses and myelinated axons in the SLM. White matter pathology deserves further attention in patients suffering from tauopathy and Alzheimer's disease.
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Chakroborty S, Stutzmann GE. Calcium channelopathies and Alzheimer's disease: insight into therapeutic success and failures. Eur J Pharmacol 2013; 739:83-95. [PMID: 24316360 DOI: 10.1016/j.ejphar.2013.11.012] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 10/22/2013] [Accepted: 11/07/2013] [Indexed: 01/06/2023]
Abstract
Calcium ions are versatile and universal biological signaling factors that regulate numerous cellular processes ranging from cell fertilization, to neuronal plasticity that underlies learning and memory, to cell death. For these functions to be properly executed, calcium signaling requires precise regulation, and failure of this regulation may tip the scales from a signal for life to a signal for death. Disruptions in calcium channel function can generate complex multi-system disorders collectively referred to as "calciumopathies" that can target essentially any cell type or organ. In this review, we focus on the multifaceted involvement of calcium signaling in the pathophysiology of Alzheimer's disease (AD), and summarize the various therapeutic options currently available to combat this disease. Detailing the series of disappointing AD clinical trial results on cognitive outcomes, we emphasize the urgency to design alternative therapeutic strategies if synaptic and memory functions are to be preserved. One such approach is to target early calcium channelopathies centrally linked to AD pathogenesis.
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Affiliation(s)
- Shreaya Chakroborty
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Grace E Stutzmann
- Department of Neuroscience, Rosalind Franklin University of Medicine and Science, The Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA.
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Gandy JC, Melendez-Ferro M, Bijur GN, Van Leuven F, Roche JK, Lechat B, Devijver H, Demedts D, Perez-Costas E, Roberts RC. Glycogen synthase kinase-3β (GSK3β) expression in a mouse model of Alzheimer's disease: A light and electron microscopy study. Synapse 2013; 67:313-27. [DOI: 10.1002/syn.21642] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 01/29/2013] [Indexed: 11/10/2022]
Affiliation(s)
- Johanna C. Gandy
- Department of Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
| | - Miguel Melendez-Ferro
- Department of Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
| | - Gautam N. Bijur
- Department of Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
| | - Fred Van Leuven
- Department of Human Genetics; Laboratory of Experimental Genetics and Transgenesis/Experimental Genetics Group (LEGTEGG); Katholieke Universiteit Leuven; Leuven; Belgium
| | - Joy K. Roche
- Department of Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
| | - Benoit Lechat
- Department of Human Genetics; Laboratory of Experimental Genetics and Transgenesis/Experimental Genetics Group (LEGTEGG); Katholieke Universiteit Leuven; Leuven; Belgium
| | - Herman Devijver
- Department of Human Genetics; Laboratory of Experimental Genetics and Transgenesis/Experimental Genetics Group (LEGTEGG); Katholieke Universiteit Leuven; Leuven; Belgium
| | - David Demedts
- Department of Human Genetics; Laboratory of Experimental Genetics and Transgenesis/Experimental Genetics Group (LEGTEGG); Katholieke Universiteit Leuven; Leuven; Belgium
| | - Emma Perez-Costas
- Department of Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
| | - Rosalinda C. Roberts
- Department of Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham; Alabama
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46
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Design, fabrication and characterization of a low-impedance 3D electrode array system for neuro-electrophysiology. SENSORS 2012. [PMID: 23208555 PMCID: PMC3571798 DOI: 10.3390/s121216571] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Recent progress in patterned microelectrode manufacturing technology and microfluidics has opened the way to a large variety of cellular and molecular biosensor-based applications. In this extremely diverse and rapidly expanding landscape, silicon-based technologies occupy a special position, given their statute of mature, consolidated, and highly accessible areas of development. Within the present work we report microfabrication procedures and workflows for 3D patterned gold-plated microelectrode arrays (MEA) of different shapes (pyramidal, conical and high aspect ratio), and we provide a detailed characterization of their physical features during all the fabrication steps to have in the end a reliable technology. Moreover, the electrical performances of MEA silicon chips mounted on standardized connector boards via ultrasound wire-bonding have been tested using non-destructive electrochemical methods: linear sweep and cyclic voltammetry, impedance spectroscopy. Further, an experimental recording chamber package suitable for in vitro electrophysiology experiments has been realized using custom-design electronics for electrical stimulus delivery and local field potential recording, included in a complete electrophysiology setup, and the experimental structures have been tested on newborn rat hippocampal slices, yielding similar performance compared to commercially available MEA equipments.
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47
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Early presynaptic and postsynaptic calcium signaling abnormalities mask underlying synaptic depression in presymptomatic Alzheimer's disease mice. J Neurosci 2012; 32:8341-53. [PMID: 22699914 DOI: 10.1523/jneurosci.0936-12.2012] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD)-linked presenilin (PS) mutations result in pronounced endoplasmic reticulum calcium disruptions that occur before detectable histopathology and cognitive deficits. More subtly, these early AD-linked calcium alterations also reset neurophysiological homeostasis, such that calcium-dependent presynaptic and postsynaptic signaling appear functionally normal yet are actually operating under aberrant calcium signaling systems. In these 3xTg-AD mouse brains, upregulated ryanodine receptor (RyR) activity is associated with a shift toward synaptic depression, likely through a reduction in presynaptic vesicle stores and increased postsynaptic outward currents through small-conductance calcium-activated potassium SK2 channels. The deviant RyR-calcium involvement in the 3xTg-AD mice also compensates for an intrinsic predisposition for hippocampal long-term depression (LTD) and reduced long-term potentiation (LTP). In this study, we detail the impact of disrupted RyR-mediated calcium stores on synaptic transmission properties, LTD, and calcium-activated membrane channels of hippocampal CA1 pyramidal neurons in presymptomatic 3xTg-AD mice. Using electrophysiological recordings in young 3xTg-AD and nontransgenic (NonTg) hippocampal slices, we show that increased RyR-evoked calcium release in 3xTg-AD mice "normalizes" an altered synaptic transmission system operating under a shifted homeostatic state that is not present in NonTg mice. In the process, we uncover compensatory signaling mechanisms recruited early in the disease process that counterbalance the disrupted RyR-calcium dynamics, namely increases in presynaptic spontaneous vesicle release, altered probability of vesicle release, and upregulated postsynaptic SK channel activity. Because AD is increasingly recognized as a "synaptic disease," calcium-mediated signaling alterations may serve as a proximal trigger for the synaptic degradation driving the cognitive loss in AD.
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Weissmiller AM, Wu C. Current advances in using neurotrophic factors to treat neurodegenerative disorders. Transl Neurodegener 2012; 1:14. [PMID: 23210531 PMCID: PMC3542569 DOI: 10.1186/2047-9158-1-14] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 07/26/2012] [Indexed: 12/15/2022] Open
Abstract
Neurotrophic factors are best known for their roles in both development and continued maintenance of the nervous system. Their strong potential to elicit pro-survival and pro-functional responses in neurons of the peripheral and central nervous system make them good drug candidates for treatment of a multitude of neurodegenerative disorders. However, significant obstacles remain and need to be overcome before translating the potential of neurotrophins into the therapeutic arena. This article addresses current efforts and advances in resolving these challenges and provides an overview of roadmaps for future translational research and neurotrophin-based drug developments.
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Affiliation(s)
- April M Weissmiller
- Department of Neurosciences, University of California San Diego, School of Medicine, La Jolla, CA, 92093-0649, USA.
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Dong CY, Shin D, Joo S, Nam Y, Cho KH. Identification of feedback loops in neural networks based on multi-step Granger causality. ACTA ACUST UNITED AC 2012; 28:2146-53. [PMID: 22730429 DOI: 10.1093/bioinformatics/bts354] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
MOTIVATION Feedback circuits are crucial network motifs, ubiquitously found in many intra- and inter-cellular regulatory networks, and also act as basic building blocks for inducing synchronized bursting behaviors in neural network dynamics. Therefore, the system-level identification of feedback circuits using time-series measurements is critical to understand the underlying regulatory mechanism of synchronized bursting behaviors. RESULTS Multi-Step Granger Causality Method (MSGCM) was developed to identify feedback loops embedded in biological networks using time-series experimental measurements. Based on multivariate time-series analysis, MSGCM used a modified Wald test to infer the existence of multi-step Granger causality between a pair of network nodes. A significant bi-directional multi-step Granger causality between two nodes indicated the existence of a feedback loop. This new identification method resolved the drawback of the previous non-causal impulse response component method which was only applicable to networks containing no co-regulatory forward path. MSGCM also significantly improved the ratio of correct identification of feedback loops. In this study, the MSGCM was testified using synthetic pulsed neural network models and also in vitro cultured rat neural networks using multi-electrode array. As a result, we found a large number of feedback loops in the in vitro cultured neural networks with apparent synchronized oscillation, indicating a close relationship between synchronized oscillatory bursting behavior and underlying feedback loops. The MSGCM is an efficient method to investigate feedback loops embedded in in vitro cultured neural networks. The identified feedback loop motifs are considered as an important design principle responsible for the synchronized bursting behavior in neural networks.
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Affiliation(s)
- Chao-Yi Dong
- Department of Automatic Control, Inner Mongolia University of Technology, Huhhot 010080, People's Republic of China
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50
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Pozueta J, Lefort R, Shelanski ML. Synaptic changes in Alzheimer's disease and its models. Neuroscience 2012; 251:51-65. [PMID: 22687952 DOI: 10.1016/j.neuroscience.2012.05.050] [Citation(s) in RCA: 216] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 05/14/2012] [Accepted: 05/17/2012] [Indexed: 12/15/2022]
Abstract
Alzheimer's disease (AD) is a highly prevalent neurodegenerative disorder characterized by a progressive loss of cognition and the presence of two hallmark lesions, senile plaques (SP) and neurofibrillary tangles (NFT), which result from the accumulation and deposition of the β-amyloid peptide (Aβ) and the aggregation of hyperphosphorylated tau protein, respectively. Initially, it was thought that Aβ fibrils, which make up SP, were the root cause of the massive neurodegeneration usual found in AD brains. Over time, the longstanding emphasis on fibrillar Aβ deposits and neuronal death slowly gave way to a new paradigm involving soluble oligomeric forms of Aβ, which play a prominent role in triggering the cognitive deficits by specifically targeting synapses and disrupting synaptic signaling pathways. While this paradigm is widely accepted today in the AD field, the molecular details have not been fully elucidated. In this review, we address some of the important evidence, which has led to the Aβ oligomer-centric hypothesis as well as some of the key findings concerning the effects of Aβ oligomers on synapses at a morphological and functional level. Understanding how Aβ oligomers target synapses provides an important framework for ongoing AD research, which can lead to the development of successful therapeutic strategies designed to alter or perhaps reverse the course of the disease.
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Affiliation(s)
- J Pozueta
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain and Department of Pathology and Cell Biology, Columbia University, New York, NY 10032, United States
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