IFNG and diabetes mellitus: To study how the BBB permeability changes with the development of DM, we analyzed the leakage of FITC-dextran 70 kDa in the CTR, DM-1W, DM-2W, and DM-3W groups, and investigated the inflammatory status by the measurement of the level of the interferon-gamma (IFN-γ) and the expression of the microglial purinergic receptor P2PY12 in the brain tissues.