Effect of pH, Salinity Levels, and the Alzheimer’s-associated Aβ Protein on Memory Formation and Regenerative Abilities in Planaria (Dugesia tigrina)

Alzheimer’s disease can be expressed as an early-onset or late-onset disease. Mutations of chromosomes 1, 14, and 21 are the main causes of early-onset familial Alzheimer disease (EOFAD) and can lead to the abnormal production of amyloid beta (Aβ) protein in the brain. Aβ peptides form amyloid plaques, which are toxic to neurons in the brain. Dugesia tigrina, or planaria, were used as a model organism. Planaria are regenerative, mucus-secreting flatworms that have the ability to form memories over time. Four groups of planaria (A-D) were first trained to find their food source in a maze and were then exposed to different experimental conditions in order to test the ability of the planaria to find their food source. Basic exposure to the protein did not affect the planaria’s ability to maintain memories because the mucus was able to block the chemicals from entering the bloodstream. Exposure to Aβ after killed the worms immediately, which was demonstrated to be because of a sensitivity to the pH and salinity levels in the solution. In previous studies, varying pH and salinity levels have not shown to have an adverse effect on whole planaria. This will be one of the first studies to observe the effect of pH and salinity on a bisected planarian. Overall, this study aimed to show how Aβ, pH, and salinity can affect stem cell growth and how memories may be affected by Aβ in a planarian model. This research was supported by North Country Bail Bonds, LLC.