Role of ghrelin system in neuroprotection and cognitive functions: Implications in Alzheimer's disease

► AD is a progressive neurodegenerative disorder influenced by the metabolic status. ► Ghrelin system is linked to obesity, metabolic syndrome, neuromodulation and memory. ► Ghrelin system acts autocrinely/paracrinely and its components are expressed CNS. ► We review the role of ghrelin system in neuroprotection, memory and learning. ► We discuss the influence of ghrelin system in AD, and its expression in AD patients.