INS and type 2 diabetes mellitus: Therefore the aim of this study was to explore whether dementia-related alterations in the central nervous system (CNS) such as cortical and hippocampal atrophy, cellular proliferation and neurogenesis in relevant regions, including SVZ, hippocampus and cortex, could be affected in: 1) young db/db mice (4 weeks old), when glucose levels are still controlled by increased insulin levels, 2) adult db/db mice (14 weeks old), when T2D has already clinically started, and 3) older db/db mice (26 weeks old), when T2D has evolved.