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204714 https://hdl.handle.net/2286/R.2.N.204714 http://rightsstatements.org/vocab/InC/1.0/ All Rights Reserved 2026 2028-05-01T09:57:46 75 pages Masters Thesis Academic theses en Melick, Alexandria Verpeut, Jessica L Beeman, Scott C Bimonte-Nelson, Heather A Arizona State University Partial requirement for: M.A., Arizona State University, 2026 Field of study: Psychology Alzheimer’s disease (AD) is the most common form of dementia and results from the extensive accumulation of amyloid beta (Aβ) and tau neurofibrillary tangles that disrupt normal brain cell functioning and diverse neural networks. Subsequently, cell death ensues leading to brain-wide atrophy and corresponding behavioral shifts impairing memory, personality, and daily function. Although millions of individuals suffer from AD in the United States alone, diagnosis remains difficult as physicians struggle to differentiate signs of normal aging, like memory deficits and gross motor changes, from analogous impairments characteristic of AD. Current diagnostic tools that assess grip strength and gait are loosely related to AD progression and blood-based biomarkers used to assess pathology are expensive. Emerging evidence suggest fine motor diagnostic tasks could be both accurate and accessible tools for early disease detection. The Quick Behavioral Exam to Advance Neuropsychological Screening (qBEANS), a novel upper-extremity motor task, is sensitive to AD development and accurately predicts brain amyloid, but neural mechanisms remain unknown. To investigate these fine motor shifts across the lifespan, a transgenic rat model of AD, the TgF344-AD (Tg, n=12) rat, was assessed in a novel fine motor apparatus mirroring qBEANS at 6 and 12 months of age, and compared to wildtype (Wt, n=12) age-matched littermates. Rats were tested in the Morris Water Maze (MWM) as a measure of spatial cognition and memory, as well as a grip strength task as a gross motor metric. Rats were also continuously monitored for health-related changes using a Frailty Index. In the fine motor task, Tg rats demonstrated a deficit in task performance at 6 and 12 months of age (p=.038), measured by the proportion of successful attempts over total attempts, with no significant change in performance between genotypes across ages (p=0.876). In the MWM, Tg rats swam greater distances to the platform, indicating worse performance, at only 12 months of age (p=0.0270). Both grip strength and frailty revealed no significant differences between genotypes, in line with human literature. These findings indicate the potential specificity of fine motor tasks in differentiating between genotypes, as well as detecting earlier disease-related decline. Aging Neurosciences Animal sciences Alzheimer's Disease Dementia Fine Motor Function Rat TgF344-AD Fine Motor Function in the TgF344-AD Rat Model Represents a Reliable Early-diagnostic Measure for Studying Early-onset Alzheimer’s Disease and Progression