Serotonin 5-HT1A receptor binding potential declines with age as measured by [C-11]WAY-100635 and PET

Positron emission tomography (PET) and [C-11]WAY-100635 were used to examin e tile effect of age on serotonin 1A (5-HT1A) receptor binding potential (B P) in 19 healthy subjects. Regions of interest (ROI) were drawn on the co-r egistered magnetic resonance imaging (MRI) ii? orbitofrontal (OFC), dorsola teral prefrontal (DLPFC), anterior cingulate (ACC), lateral (LTC), and medi otemporal (MTC), parietal, occipital and cerebellar cortex, and the raphe n uclei. BP values were calculated using a simplified reference tissue method . In addition, a voxelwise analysis suns performed using SPM99. Voxelwise a nalysis revealed a significant global decrease of 5-HT1A BP with age (sct l evel < .001). ROI analysis revealed significant age-related 5-HT1A BP decre ases in DLPFC (r = -0.56), ACC (v = -0.44), OFC (r = -0.42), LTC (r = -0.40 ), parietal (r = -0.65), and occipital cortex (u = -0.43), but not in MTC o r raphe nuclei. Overall, cortical 5-HT1A BP declined by approximately 20% p er decade, except for the MTC, where me did not find a significant age effe ct. Hence, careful age matching may be recommended for future studies using PET and [C-11]WAY-200635 to examine 5-HT1A receptors. (C) 2001 American Co llege of Neuropsychopharmacology. Published by Elsevier Science Inc.