Publication Date
2025
Document Type
Thesis
Committee Members
Sherif M. Elbasiouny, Ph.D. (Advisor); Andrew A. Voss, Ph.D. (Committee Member); Jaime E. Ramirez-Vick, Ph.D. (Committee Member)
Degree Name
Master of Science in Biomedical Engineering (MSBME)
Abstract
Age-related weakness remains poorly understood as the underlying mechanisms remain unclear. While synaptic input and muscular changes have been investigated with age, intrinsic motoneuron excitability alterations are often overlooked. This thesis provides the first direct assessment of intrinsic excitability and ion channel properties of spinal α-MNs from male and female mice across three ages: young, middle aged, and old. Our findings reveal a decline in intrinsic excitability of motoneurons with age in both sexes. Mechanistic analysis shows sex specific differences: female motoneurons exhibit increased dendritic size, hyperpolarized RMP, and SK channel overactivation, whereas males show only SK overactivation with age. Additionally, old male and female mice exhibit reduced net PIC amplitude, relative net PIC, and net PIC density. Kv2.1 current increases in old female slow motoneurons compared to young slow motoneurons. These findings reveal novel mechanisms underlying age-related weakness, offering insights into neuromuscular changes that contribute to functional decline in aging.
Page Count
94
Department or Program
Department of Biomedical, Industrial & Human Factors Engineering
Year Degree Awarded
2025
Copyright
Copyright 2025, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.
