Graduate student Rhys Kephart will be defending his thesis titled “Capturing the Varied Expression of the Triad of Motor Symptoms in Parkinson’s Disease.”

Rhys Kephart thesis defense

• Date: Friday, April 10
• Time: 11 a.m.-noon
• Location: IST 1062
• Current major: M.S. student of mechanical engineering and B.S. mechanical engineering
• Thesis committee chair: Dr. Christopher Kelley
• Committee members: Dr. Apurva Patel and Dr. Edwar Romero-Ramirez

Abstract

Parkinson’s disease (PD) is a progressive neurological disorder caused by the gradual death of neurons throughout the body. This neuron death particularly affects several key neurotransmitter-producing neurons, including dopaminergic, serotonergic, noradrenergic, and cholinergic neurons located in the substantia nigra pars compacta, raphe nuclei, locus coeruleus, and nucleus basalis, respectively.

Dopaminergic neurons are most associated with PD, with the decrease in dopamine believed to be the primary driver behind the “triad” of parkinsonian motor symptoms: bradykinesia, rigidity, and tremor. However, current theories for how dopamine depletion modifies human motor control do not yet connect all three symptoms to this single dysfunction.

This work expands on a previous tremor model based on unstable feedback to capture all three symptoms.

This model explores the possible contributions that several neurotransmitters may have on PD symptom expression. This new type of model may capture the various sub-types of PD based on the relative levels of neuron death in different brain regions. This knowledge could provide insight into how differing disease progression across brain regions may produce the varying symptoms experienced across PD patients. A movement study is currently being conducted, where participants perform tasks that can be recreated through simulations of the model to assess its ability to capture both healthy and parkinsonian movements.

For more information, please contact Rhys Kephart.