Sweet old memories: a review of the experimental models of the association between diabetes, senility and dementia.

As the burden of Alzheimer's dementia rises, so does our understanding of the cellular and molecular basis of this neurodegenerative disease. Some of the recent advances in the aetiopathogenesis of neurodegeneration include the finding that insulin receptor signalling is key to neurogenesis and synaptogenesis in the brain, especially in areas related to memory formation and storage, including the hippocampus. This suggests an association between impaired insulin receptor signalling and neurodegenerative events. To decipher this association, several animal models are being employed. Such models include transgenic and non-transgenic animals that range from invertebrates (Drosophila melanogaster and Caenorhabditis elegans), to vertebrates (mouse, rats and primates). The current review is an account of such models and how they have contributed to our understanding of the relationship between type 2 diabetes mellitus, ageing and dementia.