INSR and type 2 diabetes mellitus: Conversely, another study using Tet29 animals, a transgenic rat model of T2D in which the insulin receptor is knocked down via doxycycline-induced RNA interference, reported that, at gestational day 21, pups have reduced Iba1 expression in the hippocampus compared to pups from normoglycemic dams, but both groups showed similar microglial cell density [261].