Title: Analysis of ion current fluctuations in multi-compartment models of electrically stimulated neurons
Other Titles: Analyse der Ionenstromstochastizität in multi-compartment Modellen elektrisch stimulierter Neuronen
Language: English
Authors: Tanzer, Thomas 
Qualification level: Doctoral
Advisor: Rattay, Frank 
Assisting Advisor: Sajedi, Sogand Sadat 
Issue Date: 2021
Citation: 
Tanzer, T. (2021). Analysis of ion current fluctuations in multi-compartment models of electrically stimulated neurons [Dissertation, Technische Universität Wien]. reposiTUm. https://doi.org/10.34726/hss.2021.50981
Number of Pages: 154
Qualification level: Doctoral
Abstract: 
In many human cases neurons are experimentally poorly accessible, introducing the need for computer simulations to study their behavior. In order to model nerve impulses, the electrical activity of neurons is described by systems of differential equations, which in the case of this work are based on the principle of the Hodgkin and Huxley equations. These were used to create models that describe the individual parts of a neuron and, subsequently, the representation of an entire neuron. In addition to straight nerve fibers, a 2D pathway in the basal turn of the human cochlear was simulated to account for real anatomical conditions. This allowed us to study the effects of displacements of the externally stimulating electrode for real cochlear implant situations. The relative spread (RS), introduced by Verveen and representing the coefficient of variation of the cumulative Gaussian distribution, served as the central metric for stochasticity.We showed (i) that the placement of the electrode over dendritic regions leads to significantly larger RS than stimulation over soma, indicating that the site of origin of the AP is important for the RS. (ii) the inverse relationship of RS to diameter, (iii) long internodes lead to a reduction in spontaneous firing behavior, (iv) there is an inverse linear relationship between RS and myelin conductivity and (v) that if the noise transmission time (Dt) is changed, the default value to 0.0025ms of knoise has to be multiplied by the factor (0.0025/Dt)^(1/2)*knoise(0.0025).
Keywords: simulation; stimulation; relative spread; excitation; noise
URI: https://doi.org/10.34726/hss.2021.50981
http://hdl.handle.net/20.500.12708/18881
DOI: 10.34726/hss.2021.50981
Library ID: AC16385590
Organisation: E101 - Institut für Analysis und Scientific Computing 
Publication Type: Thesis
Hochschulschrift
Appears in Collections:Thesis

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