1
|
Courdurier M, Medina LE, Paduro E. Analysis of neural activation in time-dependent membrane capacitance models. J Math Biol 2025; 90:58. [PMID: 40327111 DOI: 10.1007/s00285-025-02218-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2025] [Revised: 03/27/2025] [Accepted: 04/04/2025] [Indexed: 05/07/2025]
Abstract
Most models of neurons incorporate a capacitor to account for the marked capacitive behavior exhibited by the cell membrane. However, such capacitance is widely considered constant, thereby neglecting the possible effects of time-dependent membrane capacitance on neural excitability. This study presents a modified formulation of a neuron model with time-dependent membrane capacitance and shows that action potentials can be elicited for certain capacitance dynamics. Our main results can be summarized as: (a) it is necessary to have significant and abrupt variations in the capacitance to generate action potentials; (b) certain simple and explicitly constructed capacitance profiles with strong variations do generate action potentials; (c) forcing abrupt changes in the capacitance too frequently may result in no action potentials. These findings can have great implications for the design of ultrasound-based or other neuromodulation strategies acting through transiently altering the membrane capacitance of neurons.
Collapse
Affiliation(s)
- Matías Courdurier
- Departamento de Matemática, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Macul, Santiago, Chile
| | - Leonel E Medina
- Facultad de Ingeniería, Universidad de Santiago de Chile, Avda. Víctor Jara 3659, Santiago, Chile
| | - Esteban Paduro
- Instituto de Ingeniería Matemática y Computacional, Facultad de Matemáticas, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Macul, Santiago, Chile.
| |
Collapse
|
2
|
Lavrentovich MO, Carrillo JMY, Collier CP, Katsaras J, Bolmatov D. Curvature Memory in Electrically Stimulated Lipid Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2025; 41:3157-3165. [PMID: 39871541 DOI: 10.1021/acs.langmuir.4c03799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2025]
Abstract
We demonstrate, using non-equilibrium molecular dynamics simulations, that lipid membrane capacitance varies with surface charge accumulation linked to membrane shape and curvature changes. Specifically, we show that lipid membranes exhibit a hysteretic response when exposed to oscillatory electric fields. The electromechanical coupling in these membranes leads to hysteretic buckling, in which the membrane can spontaneously buckle in one of two distinct directions along the electric field, even for the same ionic charge accumulation at the water-membrane interface. In this regard, these binary buckled membrane states suggest potential applications in neuromorphic computing. Their bistable nature, characterized by two distinct and stable configurations, could serve as a foundation for implementing memory storage systems and logic operations. Furthermore, we introduce a circuit model that captures these dynamic effects, offering insights into emergent memory effects in electrically stimulated lipid membranes. Finally, this work presents lipid bilayers as dynamic, adaptable elements and suggests a new platform for exploring energy storage, information processing, and memory encoding at the lipid membrane level.
Collapse
Affiliation(s)
- Maxim O Lavrentovich
- Department of Earth, Environment, and Physics, Worcester State University, Worcester, Massachusetts 01602, United States
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Jan-Michael Y Carrillo
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Charles Patrick Collier
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - John Katsaras
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Dima Bolmatov
- Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, United States
- Shull-Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| |
Collapse
|
3
|
Collier CP, Bolmatov D, Lydic R, Katsaras J. Neuronal Plasma Membranes as Supramolecular Assemblies for Biological Memory. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2025; 41:2973-2979. [PMID: 39825832 DOI: 10.1021/acs.langmuir.4c03375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2025]
Abstract
Biological memory is the ability to develop, retain, and retrieve information over time. Currently, it is widely accepted that memories are stored in synapses (i.e., connections between brain cells throughout the brain) through a process known as synaptic plasticity, which leads to either long-term potentiation (LTP) or long-term depression (LTD). However, the strengthening (LTP) and weakening (LTD) of synapses involve post-translational modifications to neural networks requiring de novo gene expression, a lengthy and energetically expensive process. Recently, we observed that lipid bilayers in the absence of peptides/proteins are capable of LTP, not unlike what has been observed in mammals and birds. As such, this finding has prompted us to postulate that the lipid bilayer provides a good model for understanding the molecular basis of biological memory. In this article, we discuss the status, challenges, and opportunities of neuronal plasma membranes as structures for biological memory and learning, therapeutic targets for various brain disorders, and platforms for neural network developments.
Collapse
Affiliation(s)
- C Patrick Collier
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Dima Bolmatov
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Ralph Lydic
- Department of Psychology, The University of Tennessee, Knoxville, Tennessee 37996, United States
| | - John Katsaras
- Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996, United States
- Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| |
Collapse
|
4
|
Bridi MC, Luo N, Kim G, Menarchek BJ, Lee RA, Rodriguez B, Severin D, Moreno C, Contreras A, Wesselborg C, O’Ferrall C, Patel R, Bertrand S, Kannan S, Kirkwood A. Daily oscillation of the excitation/inhibition ratio is disrupted in two mouse models of autism. iScience 2025; 28:111494. [PMID: 39850357 PMCID: PMC11754079 DOI: 10.1016/j.isci.2024.111494] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2024] [Revised: 11/13/2024] [Accepted: 11/26/2024] [Indexed: 01/25/2025] Open
Abstract
Alterations to the excitation/inhibition (E/I) ratio are postulated to underlie behavioral phenotypes in autism spectrum disorder (ASD) patients and mouse models. However, in wild type mice the E/I ratio is not constant, but instead oscillates across the 24-h day. Therefore, we tested whether E/I regulation, rather than the overall E/I ratio, is disrupted in two ASD-related mouse lines: Fmr1 KO and BTBR, models of syndromic and idiopathic ASD, respectively. The E/I ratio is dysregulated in both models, but in different ways: the oscillation is lost in Fmr1 KO and reversed in BTBR mice. Phenotypes in both models associate with differences the timing of excitatory and inhibitory synaptic transmission and endocannabinoid signaling compared to wild type mice, but not with altered sleep. These findings raise the possibility that ASD-related phenotypes may be produced by a mismatch between E/I and behavioral state, rather than alterations to overall E/I levels per se.
Collapse
Affiliation(s)
- Michelle C.D. Bridi
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
- Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Nancy Luo
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Grace Kim
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | | | - Rachel A. Lee
- Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Bryan Rodriguez
- Department of Neuroscience, West Virginia University, Morgantown, WV, USA
| | - Daniel Severin
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Cristian Moreno
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Altagracia Contreras
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Christian Wesselborg
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Caroline O’Ferrall
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Ruchit Patel
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sarah Bertrand
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Sujatha Kannan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alfredo Kirkwood
- Zanvyl Krieger Mind/Brain Institute, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|