Fig. 2. (A) Immunostaining for the long form of the leptin receptor (Ob-R) in cross-sections of mouse cortical bone (c), showing positive staining in periosteal cells (p) relative to control samples (no primary antibody). (B) Increased number of bone marrow adipocytes (asterisks) in bone cross-sections from POUND mice lacking both forms of the leptin receptor (lb/lb) compared to marrow from normal lean mice. (C) Peripheral, direct (bone-derived mesenchymal stromal cells [BMSC]) and central (hypothalamic) pathways through which leptin alters pathways regulating osteogenesis and adipogenesis in bone marrow. beta-AR, beta-adrenergic receptor.