Effects of sex, age, and aggressive traits in man on brain serotonin 5-HT1A receptor binding potential measured by PET using [C-11]WAY-100635

Serotonin (5-HT) 1A receptors have been implicated in a variety of conditions including, depression, suicidal behavior, and aggression. Post-mortem brain studies and in vivo imaging studies report a variety of age and sex effects on brain 5-HT(1A) binding. Behavioral data from 5-HT(1A) specific pharmacological challenges suggest a role for 5-HT(1A) receptors in aggression. The goal of the present study was to determine age, sex, and severity of life-time aggression effects on 5-HT(1A) binding potential (BP) in vivo using positron emission tomography (PET) and the high affinity 5-HT(1A) antagonist, [carbonyl-C-11]WAY-100635 in 12 healthy females (ages 41.0+/-15.7 years) and 13 healthy males (ages 39.6+/-15.5 years). Regions of interest included the dorsal raphe, anterior cingulate cortex, cingulate body, hippocampus, amygdala, medial prefrontal cortex (PFC), and orbital PFC. No significant correlation between age and BP was detected in any brain region. MANOVA of the first three principle components demonstrated a significantly higher BP in females compared with males (P=0.0127). Post-hoc tests confirmed sex differences (P