Publication Date

2018

Document Type

Thesis

Committee Members

Andrew Voss (Advisor), Mark Rich (Committee Member), Lynn Hartzler (Committee Member)

Degree Name

Master of Science (MS)

Abstract

Huntington’s disease (HD) is a degenerative disorder caused by expanded CAG repeats in the Huntingtin gene, which results in cognitive problems as well as muscle weakness, chorea, rigidity, and dystonia. Most research in HD has focused on neurodegeneration, but recent studies have found peripheral defects that may help explain the debilitating motor symptoms of HD. We have shown that skeletal muscle from the R6/2 transgenic mouse model of HD is hyperexcitable due to decreases in resting chloride and potassium currents. Other groups have speculated that the fast voltage-gated sodium channels may be affected in Huntington’s disease as well. To fully understand membrane excitability, we looked at the fast voltage-gated sodium currents in voltage clamped flexor digitorum brevis and interosseous muscle fibers from late-stage R6/2 mice and age-matched siblings. Action potential trains were recorded to determine how the defects in chloride, potassium, and possibly sodium channels impact repeated action potentials. Voltage dependence of the muscle fast voltage-gated sodium channels was shifted in R6/2 mice. Action potential trains contained slower, smaller action potentials in diseased muscle.

Page Count

69

Department or Program

Department of Biological Sciences

Year Degree Awarded

2018


Included in

Biology Commons

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