title: Symptoms of aging tied to brain chemistry.
mesh_terms: D000339:Affect / Q000502:physiology; D000368:Aged; D000375:Aging / Q000502:physiology*; D001921:Brain / Q000000981:diagnostic imaging; D001923:Brain Chemistry; D003071:Cognition / Q000502:physiology; D006801:Humans; D008019:Life Style; D017448:Receptors, Dopamine D2 / Q000032:analysis* / Q000172:deficiency; D014055:Tomography, Emission-Computed
chemical_list: D017448:Receptors, Dopamine D2