In the last two decades insulin signalling and protection in brain has emerged as a novel field of research.Although growing evidence supports the hypothesis that dysfunction of neuronal glucose utilization and metabolism and/or in insulin receptor signal transduction cascade is involved in Alzheimer s disease pathogenesis,the role of insulin on oxidative stress- and diabetes-induced neuronal dysfunction and death has been less investigated.This book,therefore,provides new experimental evidences that reveal the cascade of events underlying the putative neuroprotective effect of insulin on neurotransmission,and neuronal function and survival associated with oxidative stress and diabetes.More specifically,it is shown that insulin has a neuromodulatory role,and also that it activates neuronal receptor-mediated signalling,controlling antioxidant defences,glucose metabolism and preventing against apoptosis associated with oxidative stress.Herewith,we can find valuable tools (especially to Neuroendocrinologists,Neurochemists and Pharmacologists) to establish insulin as a promising therapeutic agent,particularly in normoglycemia conditions.