Changes in the levels of osteocalcin secreted by OBs may be associated with age‐related cognitive decline.[290] Osteocalcin can alleviate CNS lesions, protect damaged neurons, and mitigate central lesions in AD mice by regulating lipid metabolism.[291] Osteocalcin binds to midbrain neurons and promotes the production of dopamine neurotransmitters,[292] suggesting a relationship between PD and bone metabolism. The gene discussed is BGLAP; the disease is Parkinson disease.