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Yang G, Hu W, He L, Dou L. Nonlinear causal network learning via Granger causality based on extreme support vector regression. CHAOS (WOODBURY, N.Y.) 2024; 34:023127. [PMID: 38377295 DOI: 10.1063/5.0183537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/22/2024] [Indexed: 02/22/2024]
Abstract
For complex networked systems, based on the consideration of nonlinearity and causality, a novel general method of nonlinear causal network learning, termed extreme support vector regression Granger causality (ESVRGC), is proposed. The nonuniform time-delayed influence of the driving nodes on the target node is particularly considered. Then, the restricted model and the unrestricted model of Granger causality are, respectively, formulated based on extreme support vector regression, which uses the selected time-delayed components of system variables as the inputs of kernel functions. The nonlinear conditional Granger causality index is finally calculated to confirm the strength of a causal interaction. Generally, based on the simulation of a nonlinear vector autoregressive model and nonlinear discrete time-delayed dynamic systems, ESVRGC demonstrates better performance than other popular methods. Also, the validity and robustness of ESVRGC are also verified by the different cases of network types, sample sizes, noise intensities, and coupling strengths. Finally, the superiority of ESVRGC is successful verified by the experimental study on real benchmark datasets.
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Affiliation(s)
- Guanxue Yang
- School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Weiwei Hu
- School of Electrical and Information Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Lidong He
- School of Automation, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Liya Dou
- Department of Automation, Beijing University of Chemical Technology, Beijing 100029, China
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Ghadimi A, Steiner LA, Popovic MR, Milosevic L, Lankarany M. Inferring stimulation induced short-term synaptic plasticity dynamics using novel dual optimization algorithm. PLoS One 2022; 17:e0273699. [PMID: 36129852 PMCID: PMC9491593 DOI: 10.1371/journal.pone.0273699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Accepted: 08/12/2022] [Indexed: 12/05/2022] Open
Abstract
Experimental evidence in both human and animal studies demonstrated that deep brain stimulation (DBS) can induce short-term synaptic plasticity (STP) in the stimulated nucleus. Given that DBS-induced STP may be connected to the therapeutic effects of DBS, we sought to develop a computational predictive model that infers the dynamics of STP in response to DBS at different frequencies. Existing methods for estimating STP–either model-based or model-free approaches–require access to pre-synaptic spiking activity. However, in the context of DBS, extracellular stimulation (e.g. DBS) can be used to elicit presynaptic activations directly. We present a model-based approach that integrates multiple individual frequencies of DBS-like electrical stimulation as pre-synaptic spikes and infers parameters of the Tsodyks-Markram (TM) model from post-synaptic currents of the stimulated nucleus. By distinguishing between the steady-state and transient responses of the TM model, we develop a novel dual optimization algorithm that infers the model parameters in two steps. First, the TM model parameters are calculated by integrating multiple frequencies of stimulation to estimate the steady state response of post-synaptic current through a closed-form analytical solution. The results of this step are utilized as the initial values for the second step in which a non-derivative optimization algorithm is used to track the transient response of the post-synaptic potential across different individual frequencies of stimulation. Moreover, in order to confirm the applicability of the method, we applied our algorithm–as a proof of concept–to empirical data recorded from acute rodent brain slices of the subthalamic nucleus (STN) during DBS-like stimulation to infer dynamics of STP for inhibitory synaptic inputs.
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Affiliation(s)
- Alireza Ghadimi
- Krembil Research Institute – University Health Network (UHN), Toronto, Ontario, Canada
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network (UHN), Toronto, Ontario, Canada
| | - Leon Amadeus Steiner
- Krembil Research Institute – University Health Network (UHN), Toronto, Ontario, Canada
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
- Institute of Neurophysiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Milos R. Popovic
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network (UHN), Toronto, Ontario, Canada
| | - Luka Milosevic
- Krembil Research Institute – University Health Network (UHN), Toronto, Ontario, Canada
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network (UHN), Toronto, Ontario, Canada
| | - Milad Lankarany
- Krembil Research Institute – University Health Network (UHN), Toronto, Ontario, Canada
- Institute of Biomaterials & Biomedical Engineering (IBBME), University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network (UHN), Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Zakharova A, Strelkova G, Schöll E, Kurths J. Introduction to focus issue: In memory of Vadim S. Anishchenko: Statistical physics and nonlinear dynamics of complex systems. CHAOS (WOODBURY, N.Y.) 2022; 32:010401. [PMID: 35105142 DOI: 10.1063/5.0082335] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 06/14/2023]
Affiliation(s)
- Anna Zakharova
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Galina Strelkova
- Institute of Physics, Saratov State University, 83 Astrakhanskaya Street, Saratov 410012, Russia
| | - Eckehard Schöll
- Institut für Theoretische Physik, Technische Universität Berlin, Hardenbergstr. 36, 10623 Berlin, Germany
| | - Jürgen Kurths
- Potsdam Institute for Climate Impact Research, Telegraphenberg A 31, 14473 Potsdam, Germany
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