Title

Effects of methylene blue on nerve cell viability in an Alzheimer's disease hyperglycemic in vitro model.

Date of Award

5-1-2015

Document Type

Thesis

School

College of Liberal Arts

Degree Name

Bachelor in Arts

Abstract

Alzheimer's disease (AD) is a neurodegenerative disease pronounced by memory impairment as well as a loss of one's cognitive abilities. Type 2 Diabetes (T2DM) is a metabolic disorder marked by abnormal glucose regulation and decrease in insulin signaling. This study examines the effects of a T2DM-like state pathways, including hyperglycemic and insulin-free conditions, on neurodegeneration using an in vitro embryonic nerve cell culture model. Results suggest high glucose (150 mM) levels and insulin deprivation independently induce neurodegeneration, while a combined effect of two times more neurodegeneration was observed when both conditions were present. This thesis also examines the effect of a potential AD drug called Methylene Blue (MB) on preventing neurodegeneration induced by hyperglycemic and insulin deprived conditions. Results suggest MB independently has no neurotoxic effects on nerve cells at a low dose of 100nM. In insulin deprived conditions, MB had no neuroprotective effect, while in insulin conditions MB showed potential signs of reducing neurodegeneration through an insulin-mediated pathway. The effects of MB on neuronal health and microtubule stability in the presence of high glucose and insulin deprivation was also examined in a preliminary study using immunostaining. Neuritic intensity and neurite counts were used to quantitatively measure the effects of MB on neuronal microtubule stability, while fluorescent images and stain brightness were used to qualitatively measure MB's effects on microtubule stability. An increase in neurite counts and neuritic intensity were observed in MB conditions; however, no conclusions can be made due to the limited amount of data. Similarly, no conclusions could be made on qualitative observations of increased dendritic branching and axon lengths in MB containing conditions, due to limited data. Besides running more replicates of the experiments conducted in this study to further support my hypotheses, other future experiments will focus on measuring the effects of MB on a more specific neurodegenerative model of AD using hyperglycemic and insulin-free conditions along with AD pathology to induce neurodegeneration.