Sex Differences in Amphetamine-Induced Displacement of [ ¹⁸ F]Fallypride in Striatal and Extrastriatal Regions: A PET Study

Objective: The authors examined gender differences in d -amphetamine-induced displacements of [ ¹⁸ F]fallypride in the striatal and extrastriatal brain regions and the correlations of these displacements with cognition and sensation seeking. Method: Six women and seven men underwent positron emission tomography (PET) 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 dopamine 2 (D ₂ ) receptor binding potential. Results: Parametric images of dopamine release suggest that the female subjects had greater dopamine release than the male subjects in the right globus pallidus and right inferior frontal gyrus. Gender differences were observed in correlations of changes in cognition and sensation seeking with regional dopamine release. Conclusion: Findings revealed a greater dopamine release in women as well as gender differences in the relationship between regional dopamine release and sensation seeking and cognition.