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

Positron emission tomography (PET) and [C-11]WAY-100635 were used to examine the effect of age on serotonin 1A (5-HT1A) receptor binding potential (BP) in 19 healthy subjects. Regions of interest (ROI) were drawn on the co-registered magnetic resonance imaging (MRI) ii? orbitofrontal (OFC), dorsolateral prefrontal (DLPFC), anterior cingulate (ACC), lateral (LTC), and mediotemporal (MTC), parietal, occipital and cerebellar cortex, and the raphe nuclei. BP values were calculated using a simplified reference tissue method. In addition, a voxelwise analysis suns performed using SPM99. Voxelwise analysis revealed a significant global decrease of 5-HT1A BP with age (sct level < .001). ROI analysis revealed significant age-related 5-HT1A BP decreases 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 or raphe nuclei. Overall, cortical 5-HT1A BP declined by approximately 20% per decade, except for the MTC, where me did not find a significant age effect. 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 College of Neuropsychopharmacology. Published by Elsevier Science Inc.