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Sun S, Ma Q, Sheng Q, Huang S, Wu C, Liu J, Xu J. Amyloid-β Oligomer-Induced Electrophysiological Mechanisms and Electrical Impedance Changes in Neurons. SENSORS (BASEL, SWITZERLAND) 2024; 24:1211. [PMID: 38400369 PMCID: PMC10892449 DOI: 10.3390/s24041211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/04/2024] [Accepted: 02/10/2024] [Indexed: 02/25/2024]
Abstract
Amyloid plays a critical role in the pathogenesis of Alzheimer's disease (AD) and can aggregate to form oligomers and fibrils in the brain. There is increasing evidence that highly toxic amyloid-β oligomers (AβOs) lead to tau protein aggregation, hyperphosphorylation, neuroinflammation, neuronal loss, synaptic loss, and dysfunction. Although the effects of AβOs on neurons have been investigated using conventional biochemical experiments, there are no established criteria for electrical evaluation. To this end, we explored electrophysiological changes in mouse hippocampal neurons (HT22) following exposure to AβOs and/or naringenin (Nar, a flavonoid compound) using electrical impedance spectroscopy (EIS). AβO-induced HT22 showed a decreased impedance amplitude and increased phase angle, and the addition of Nar reversed these changes. The characteristic frequency was markedly increased with AβO exposure, which was also reversed by Nar. The AβOs decreased intranuclear and cytoplasmic resistance and increased nucleus resistance and extracellular capacitance. Overall, the innovative construction of the eight-element CPE-equivalent circuit model further reflects that the pseudo-capacitance of the cell membrane and cell nucleus was increased in the AβO-induced group. This study conclusively revealed that AβOs induce cytotoxic effects by disrupting the resistance characteristics of unit membranes. The results further support that EIS is an effective technique for evaluating AβO-induced neuronal damage and microscopic electrical distinctions in the sub-microscopic structure of reactive cells.
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Affiliation(s)
- Shimeng Sun
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Qing Ma
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Qiyu Sheng
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Shangwei Huang
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Chenxia Wu
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
| | - Junsong Liu
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China
| | - Jia Xu
- Department of Physiology and Pharmacology, Health Science Center, Ningbo University, Ningbo 315211, China; (S.S.); (Q.M.); (Q.S.); (S.H.); (C.W.)
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Wang H, Dai J, Wang C, Gao Z, Liu Y, Dai M, Zhao Z, Yang L, Tan G. Assessment of Low Back Pain in Helicopter Pilots Using Electrical Bio-Impedance Technique: A Feasibility Study. Front Neurosci 2022; 16:883348. [PMID: 35911977 PMCID: PMC9330605 DOI: 10.3389/fnins.2022.883348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Low back pain (LBP) is known to pose a serious threat to helicopter pilots. This study aimed to explore the potential of electrical bio-impedance (EBI) technique with the advantages of no radiation, non-invasiveness and low cost, which is intended to be used as a daily detection tool to assess LBP in primary aviation medical units. The LBP scales (severity) in 72 helicopter pilots were assessed using a pain questionnaire, while the bilateral impedance measurements of the lumbar muscle were carried out with a high precision EBI measurement system. Results showed that the modulus of lumbar muscle impedance increased with LBP scale whereas the phase angle decreased. For different LBP scales, significant differences were found in the modulus of lumbar muscle impedance sum on both sides (Zsum), as well as in the modulus and phase angle of lumbar muscle impedance difference between both sides (Zdiff and ϕdiff), respectively (P < 0.05). Moreover, Spearman’s correlation analysis manifested a strong correlation between Zsum and LBP scale (R = 0.692, P < 0.01), an excellent correlation between Zdiff and LBP scale (R = 0.86, P < 0.01), and a desirable correlation between ϕdiff and LBP scale (R = −0.858, P < 0.01). In addition, receiver operator characteristic analysis showed that for LBP prediction, the area under receiver operator characteristic curve of Zsum, Zdiff, and ϕdiff were 0.931, 0.992, and 0.965, respectively. These findings demonstrated that EBI could sensitively and accurately detect the state of lumbar muscle associated with LBP, which might be the potential tool for daily detection of LBP in primary aviation medical units.
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Affiliation(s)
- Hang Wang
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
| | - Jing Dai
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
| | - Chunchen Wang
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
| | - Zhijun Gao
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
| | - Yang Liu
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
| | - Meng Dai
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
| | - Zhanqi Zhao
- Department of Biomedical Engineering, Fourth Military Medical University, Xi’an, China
- Institute of Technical Medicine, Furtwangen University, Villingen-Schwenningen, Germany
| | - Lin Yang
- Department of Aerospace Medicine, Fourth Military Medical University, Xi’an, China
- *Correspondence: Lin Yang,
| | - Guodong Tan
- Air Force Medical Center, Fourth Military Medical University, Beijing, China
- Guodong Tan,
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Robustness for the Starting Point of Two Iterative Methods for Fitting Debye or Cole–Cole Models to a Dielectric Permittivity Spectrum. APPLIED SCIENCES-BASEL 2022. [DOI: 10.3390/app12115698] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Curve-fitting means the determination of the set of parameters that best fit the input data set as expressed by a given function that is usually non-linear. The paper addresses the curve fitting of Debye and Cole–Cole models to a dielectric permittivity spectrum. The success of a nonlinear curve fit heavily depends on the choice of the algorithm and how close the starting point is to the solution. For these reasons, two different algorithms, the Levenberg–Marquardt and the Variable Projection algorithms, were used for constrained optimization and compared, with particular reference to robustness with respect to the choice of the starting point of the reconstruction procedure. The dielectric spectrum of blood plasma with different glucose concentrations is taken as reference data and a Monte Carlo analysis was conducted to evaluate accuracy and precision in the two methods provided as the distance of the initial parameters from the true value’s changes. In general, both algorithms with constraints on the parameters provide good results for practical situations, although the Variable Projection Algorithm has a greater computational burden for large data sets.
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