TLR4 and Impaired glucose tolerance: In this model, impaired glucose tolerance, increases in cholesterol and leptin blood levels, brain and liver overexpression of Toll-like receptor 4 (Tlr4), decreased expression of mitochondrial markers peroxisome proliferator-activated receptor gamma coactivator 1 (Ppargc1) a and b, and decreased Sert expression in the brain are all features.