Graduation Term

2021

Degree Name

Master of Science (MS)

Department

Department of Mathematics

Committee Chair

Epaminondas Rosa

Committee Member

Olcay Akman

Abstract

Thermotaxis in the nematode Caenorhabditis elegans (C. elegans) is studied at the cellular scale of the amphid finger-like ciliated (AFD) neurons, which have previously been shown to be essential for thermoreception. The voltage and calcium signals of AFD during temperature stimuli are described with ordinary differential equations. The primary calcium model is a modified version of that published by Kuramochi and Doi in 2017 to explain the calcium responses of the chemosensitive amphid single-ciliated right (ASER) neuron to fluctuations in extracellular salt concentration. To account for the effects of temperature, changes to the stimuli conditions under which inactivation takes place are made and two temperature-sensitive Arhennius parameters are added. This model is validated using experimental data from Clark et al. (2006) and Yoshida et al. (2016). The AFD membrane currents during a voltage-clamp are found to be described by three simple linear equations that are analytically tractable. The membrane electrodynamics model is validated using experimental data from Ramot et al. (2008). Three parameters in this original model modulate the temperature sensitivity, time scale, and monotonicity of the current response during a voltage clamp. This work may serve as a precursor to more advanced modeling studies incorporating voltage and calcium of the AFD neuron as coupled temperature response variables. It may also play a role in guiding future fluorescence and/or patch-clamp experiments of the AFD neuron with the goal of quantifying its thermal sensitivity.

Access Type

Thesis-Open Access

DOI

https://doi.org/10.30707/ETD2021.20210719070603179925.53

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