Insulin signaling in hippocampus

Abstract

Neuroinflammation and insulin resistance are known to underlie many neurological alterations, including Alzheimer's disease. Neuroinflammation is associated with chronic microglia activation, which induces synaptic loss, and neuronal damage. Insuli n resistance, on the other hand is associated with deregulation of insulin receptor substrates (IRS - 1 and IRS - 2). Alzheimer's disease is the leading cause of dementia and is characterized by progressive, degenerative and irreversible neurological disorder , in which loss of memory and behavioral changes are observed. Given the importance of IRS1 and IRS2 in mediating insulin effects in brain, this study focuses on the distribution of these proteins in hippocampus. In addition, we aimed to evaluate the effec t of the phytohormone abscisic acid (ABA) in hippocampal neurogenesis in a model of neuroinflammation. ABA has been shown to be an insulin sensitizer in periphery and having anti - inflammatory properties also in central nervous system. The results indicated differences on the distribution, morphology and expression of insulin receptor substrates (IRS - 1 and IRS - 2) in the hippocampus. We also observed lower levels of neurogenesis in animals treated with fat diet, suggesting an influence of diet type on these levels in the hippocampus.