Characterizing variable patterns of disease onset and progression in a mouse model of Amyotrophic Lateral Sclerosis (ALS)
Abstract
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] The goal of the current study was to characterize the anatomical site(s) of onset (i.e., specific limb or craniofacial region) and pattern of disease progression in the LCN-SOD1 mouse model of ALS in order to establish a clinical phenotype classification scheme for this model. Secondary goals included determining whether clinical phenotype is inherited, and if mice with forelimb impairment had more severe dysphagia than mice with hindlimb impairment. To do this, we studied one ALS-affected male breeder and all of his offspring from 4 months of age (presymptomatic) until disease end-stage (i.e., 20% body weight loss). Limb function was assessed weekly via walking corridor and clinical scoring tests. Bulbar function was assessed via monthly videofluoroscopic swallow study (VFSS) testing and weekly tongue force testing using a force lickometer. Results from monthly data illustrated that impairment in lick rate, obtained during VFSS, was the earliest clinical sign of ALS onset, followed by limb impairment as perceived though clinical scoring. In addition, we were able to classify three distinct phenotypes from one breeder, indicating that clinical phenotype is not inherited. Finally, no significant difference was found in severity of dysphagia between the three patterns of limb impairment onset and progression, however mice with forelimb onset did have more severe foraging impairment in their home cage at 20% body weight loss than their hindlimb onset counterparts. This study provides valuable insight in to the early clinical symptoms (spinal versus bulbar), anatomical disease spread, heritability of limb phenotype, and severity of dysphagia in ALS.
Degree
M.H.S.
Thesis Department
Rights
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