title: Distinct regional age effects on [11C]AZ10419369 binding to 5-HT1B receptors in the human brain.
abstract: OBJECTIVE
  Age-related changes in the serotonin system have been described, and proposed to be associated with behavioral changes observed particularly in the elderly population. The 5-HT1B receptor is thought to have a regulatory role in a number of physiological functions, and has been implicated in several age-related diseases. The purpose of the present study was to examine if the availability of 5-HT1B receptors is decreasing with age in healthy subjects.
  
  
  METHODS
  Data from five previous studies were reanalyzed and pooled, generating data from fifty-one healthy subjects, age 20 to 70, that had been examined with positron emission tomography (PET) and the 5-HT1B specific radioligand [11C]AZ10419369 at baseline conditions. The binding potential (BPND) in cortical and subcortical areas was calculated using the simplified reference tissue model (SRTM). After correction for partial volume effects (PVEc), the correlation between age and regional BPND was examined.
  
  
  RESULTS
  A statistically significant negative correlation between age and BPND was obtained for neocortical regions and the ventral striatum (VST). The average reduction in BPND per decade was 8% in cortex and 4% in VST. The BPND in the caudate nucleus and the putamen was mainly unaffected by age.
  
  
  CONCLUSIONS
  The 5-HT1B receptor availability decreases by age in cortical regions, whereas it remains stable in the caudate nucleus and putamen. By consequence, age-matching of control subjects will be necessary in future clinical studies.
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden. Electronic address: Magdalena.Nord@ki.se.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Nord
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden; AstraZeneca Translational Science Center, Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm, Sweden.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Cselenyi
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
authors.forename: Anton
authors.initials: A
authors.lastname: Forsberg
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
authors.forename: Göran
authors.initials: G
authors.lastname: Rosenqvist
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Tiger
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Lundberg
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden.
authors.forename: Andrea
authors.initials: A
authors.lastname: Varrone
authors.affiliation: Karolinska Institutet, Department of Clinical Neuroscience, Center for Psychiatric Research, Karolinska University Hospital, SE-17176 Stockholm, Sweden; AstraZeneca Translational Science Center, Department of Clinical Neuroscience, Karolinska Institutet, SE-17176 Stockholm, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Farde
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D001921:Brain / Q000000981:diagnostic imaging*; D002250:Carbon Radioisotopes / Q000494:pharmacology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000494:pharmacology*; D044302:Receptor, Serotonin, 5-HT1B / Q000032:analysis / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals; D044302:Receptor, Serotonin, 5-HT1B
keywords: 5-HT(1B); Aging; PET; [(11)C]AZ10419369