Sex Differences in Amphetamine Induced Displacement of [F] Fallypride in Striatal and Extrastriatal Regions: A PET Study

OBJECTIVE: This study examined sex differences in d-amphetamine induced displacements of [ 18 F]fallypride in striatal and extrastriatal regions and the correlations of these displacements with cognition and sensation seeking. METHOD: Six females and seven males underwent positron emission tomography with [ 18 F]fallypride before and after an oral dose of d-amphetamine. Percent displacements were calculated using regions of interest and parametric images of DA D 2 receptor binding potential (b.p.). RESULTS: Parametric images of DA release suggest that women have greater DA release than men in the right globus pallidus and right inferior frontal gyrus. Sex differences were seen in correlations of changes in cognition and sensation seeking with regional DA release. CONCLUSIONS: This study demonstrates greater DA release in women and sex differences in the relationship of regional DA release to sensation seeking and cognition.