The role of BDNF in the central nervous system associated with hyperthyroidism and diabetes mellitus

Abstract

In the last few years, it has been suggested that deficiency and insulin resistance in the brain may be related to Alzheimer's Disease (AD), suggesting a relationship between AD and Diabetes Mellitus (DM). Besides the relationship between dysfunction of insulin signaling and AD, several studies suggest a modulation of Thyroid Hormones (TH) in insulin signaling and in the function of nervous system, and its deficiency or excess are involved in neurological symptoms. However, little is known about the effects of TH function in the adult nervous system. Moreover, TH seem to modulate neurotrophic factors such as the Brain Derived Neurotrophic Factor (BDNF), which is essential in regulating the survival, growth and maintenance of neurons. The aim of this study is evaluate the effects of TH treatment in the insulin signaling pathway, involving the BDNF in the brain of diabetic rats. For this, Wistar rats will be injected with alloxan monohydrate (diabetic rats) or citrate and treated with T3 for 30 days. These animals will be tested with a behavioral method for assessing memory changes and the levels of proteins related to insulin and BDNF signaling pathways, as well as other proteins related to survival and maintenance of neurons will be evaluated in the cortex and hippocampus by immunoblotting and immunohistochemistry, and the levels of BDNF by ELISA. We believe we can contribute to better understanding of the role of TH function in the adult nervous system. (AU)