Publication Date

2020

Document Type

Thesis

Committee Members

Sherif M. Elbasiouny, Ph.D., P.E. (Advisor); Keiichiro Susuki, M.D., Ph.D. (Committee Member); Adrian M. Corbett, Ph.D. (Committee Member); Barry Milligan, Ph.D. (Other)

Degree Name

Master of Science (MS)

Abstract

Protocol development and optimization are vital in the scientific method process. By having accurate protocols, one can properly assess the characteristics of their animal model for any given experiment. One animal newly adopted in our lab was the novel regulatable nuclear localization sequence (rNLS) mouse model. This novel mouse model displays symptoms of Amyotrophic Lateral Sclerosis (ALS) and Frontotemporal dementia (FTD), after the accumulation of the hTDP-43 (TAR DNA-binding protein 43) aggregate in the central nervous system. The expression of this protein occurs after the removal of deoxycycline from the mouse’s food source. Once the removal of the drug, this activates a tetracycline-controlled activation system, which causes expression of hTDP-43. The ability to control the expression of hTDP-43 provides the uniqueness to this ALS/FTD mouse model allowing researchers to study these fatal neurodegenerative diseases at various time points in the mouse’s timeline. In this thesis, three different studies were conduct that either developed or optimized protocols to assess characteristics of this novel rNLS mouse. The first study investigates the development of cognitive behavioural tasks designed assess working memory and learning in this mouse model. These behavioural tasks are the Y-maze, the NOR (NOR) and the Holeboard tests. In addition to developing behavioural task protocols suited for our mouse model, a comparison was also done between WT (WT) and NS (NS) rNLS mouse, which are mice part of the rNLS colony that do not have the bigenic mutation expressing ALS/FTD, to determine if NS rNLS could be used as control, the results confirm they can be used. In the second study, the Y-maze protocol was utilized in assessing short-term working-memory of rNLS mice 3 and 5 weeks off doxycycline. This preliminary study shows evidence of cognitive deficits in this mouse model as well as provides credibility to our developed protocol. The third study compares the intramuscular labelling of α-MNs (α-MNs) through the usage of Fast-Blue (FB) and Cholera-toxin B (CTB) retrograde tracers under different parameters such as different concentrations and survival days. These tracers were injected into the hindlimb muscles of WT mice and showed that despite each tracer providing its own uniqueness in labeling α-MNs was no overall difference between these retrograde tracers. However, it was discovered that using less in concentration and survival day is often advantageous then utilizing standard protocol for alpha-motoneuron labeling.

Page Count

120

Year Degree Awarded

2020

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.


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