A database of [18F]-altanserin binding to 5-HT2A receptors in normal volunteers:: normative data and relationship to physiological and demographic variables

This study presents the results of an analysis of 5-hydroxytryptamine (5-HT)(2A) receptors in 52 healthy subjects. Thirty men and twenty-two women aged between 21 and 79 years were investigated with magnetic resonance imaging (MRI) and [F-18]-altanserin positron emission tomography (PET). The distribution volumes of specific tracer binding (DV3') was calculated for 15 brain regions using either cerebellum or pons as reference regions and correlations between DV3' and physiological and demographic variables were made. The regional distribution of [F-18]-altanserin binding in the healthy human brain was in agreement with existing in vitro post-mortem human 5-HT2A data. Apart from nonspecific cerebellar binding (DV2), there was no gender difference in 5-HT2A binding. A positive correlation between cerebellar binding and age was observed and negative correlations between age and DV3' were found in all cortical regions, except occipital cortex, corresponding to a decrease in DV3' of 6% or 4% per decade with cerebellum or pons as reference regions, respectively. In several temporal and frontal cortical regions, positive correlations were found between body mass index (BMI) and DV3'. Our findings provide a resource to aid design of clinical studies of the 5-HT2A receptors. [F-18]-altanserin binding appears to be unaffected by gender, but the effects of ageing must be considered for clinical studies. The correlations between different cortical regions' 5-HT2A binding and BMI should be explored in future studies. (C) 2004 Elsevier Inc. All rights reserved.