title: Age-related decline of serotonin transporters in living human brain of healthy males.
abstract: There is growing interest in serotonin transporter (5-HTT) function in the human brain, since alteration in 5-HTT has been suggested in a variety of neurophychiatric disorders. Age-related decline in postsynaptic 5-HT receptors has been demonstrated in postmortem human studies and in vivo imaging studies, and has been assumed to be related to changes in mental function in the normal aging process. However, few studies have investigated the aging effect on 5-HTT in human brain in vivo, since the availability of suitable ligands has been limited. To investigate the aging effect on 5-HTT in living human brain, we performed positron emission tomography (PET) scans with a selective ligand for 5-HTT, [11C](+)McN5652. We examined 28 healthy male volunteers aged between 20 and 79 years. The uptake was quantified in the thalamus and midbrain by graphical analysis with the cerebellum as a reference tissue, and binding potential (BP) was used for the index of 5-HTT binding. There was a significant age-related decline in BP in the thalamus and midbrain. The decline in [11C](+)McN5652 binding was 9.6% per decade in the thalamus and 10.5% per decade in the midbrain.
authors.affiliation: Brain Imaging Project, National Institute of Radiological Sciences, Chiba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Suhara
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Okubo
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ichimiya
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Sudo
authors.forename: Makoto
authors.initials: M
authors.lastname: Inoue
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takano
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Yasuno
authors.forename: Kyosan
authors.initials: K
authors.lastname: Yoshikawa
authors.forename: Shuji
authors.initials: S
authors.lastname: Tanada
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000465:Algorithms; D001923:Brain Chemistry / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism*; D002531:Cerebellum / Q000254:growth & development / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007546:Isoquinolines; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D008636:Mesencephalon / Q000254:growth & development / Q000378:metabolism; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D012702:Serotonin Antagonists; D050486:Serotonin Plasma Membrane Transport Proteins; D013788:Thalamus / Q000254:growth & development / Q000378:metabolism; D014055:Tomography, Emission-Computed
chemical_list: D002352:Carrier Proteins; D007546:Isoquinolines; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493230:SLC6A4 protein, human; D012702:Serotonin Antagonists; D050486:Serotonin Plasma Membrane Transport Proteins; C058079:McN 5652