Fig. 4. TMJ proteoglycan content. Coronal sections (6 µm) of middle joint sites from U-diet (A) and O-diet (B) 4-month old subadults were stained with Safranin O to identify GAG content in the articular cartilage. In low-power views of the articular surface and underlying subchondral bone, more intense staining in A vs B indicates lower proteoglycan content and thus diminished articular cartilage viscoelasticity in O-diet rabbits.