title: Effects of aging on 5-HT(2A) R binding: a HRRT PET study with and without partial volume corrections.
abstract: OBJECTIVE
  We explored whether prior findings of reduction in serotonin 2A receptor (5-HT(2A) R) binding with age could be replicated and whether high resolution research tomography (HRRT) for positron emission tomography could compensate for partial volume effects in the presence of age-related brain atrophy, which has been a traditional concern for radioligand PET studies in the elderly.
  
  
  METHODS
  We derived 5-HT(2A) R nondisplaceable binding potentials (BP(ND) ) in frontal, temporal, anterior-cingulate, insula, caudate and putamen volumes of interest (VOIs) for 28 healthy subjects (mean ± SD age = 43.9 ± 17.0 years, range: 19-78 years) using HRRT. Partial volume correction (PVC) was performed in the VOI analysis.
  
  
  RESULTS
  The 5-HT(2A) R BP(ND) s decreased with age, a relationship best described by an exponential-decay regression. The BP(ND) s were found to be consistent before and after PVC, with an intra-class correlation coefficient of 0.84 and 95% confidence interval = 0.78-0.88.
  
  
  CONCLUSIONS
  These new findings update current knowledge, in that the aging process is not always uniform across the life span and suggest that PVC may not be necessary with HRRT in healthy subjects.
authors.affiliation: Centre for Addiction and Mental Health, Toronto, Ontario, Canada.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Uchida
authors.forename: Tiffany W
authors.initials: TW
authors.lastname: Chow
authors.forename: David C
authors.initials: DC
authors.lastname: Mamo
authors.forename: Shitij
authors.initials: S
authors.lastname: Kapur
authors.forename: Benoit H
authors.initials: BH
authors.lastname: Mulsant
authors.forename: Sylvain
authors.initials: S
authors.lastname: Houle
authors.forename: Bruce G
authors.initials: BG
authors.lastname: Pollock
authors.forename: Ariel
authors.initials: A
authors.lastname: Graff-Guerrero
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D011744:Pyrimidinones; D011868:Radioisotopes; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D055815:Young Adult
chemical_list: D005462:Fluorine Radioisotopes; D011744:Pyrimidinones; D011868:Radioisotopes; D044402:Receptor, Serotonin, 5-HT2A; C045359:setoperone