Effect of estradiol versus estradiol and testosterone on brain-activation patterns in postmenopausal women

In Brief Objective: To determine the effect of estradiol and testosterone on brain-activation patterns in surgically postmenopausal women viewing erotic video clips using functional magnetic resonance imaging. Design: Six women, who had undergone a bilateral oophorectomy and hysterectomy for benign disease, viewed erotic and neutral videos during functional magnetic resonance imaging while not on hormone therapy, while on estradiol therapy, and while on estradiol and testosterone therapy. Five similarly aged premenopausal women viewed the same videos. Areas of brain activation between the functional magnetic resonance imaging scans of both groups of women were compared with determine whether agonadal serum levels of sex hormones and administration of estradiol and testosterone impacted brain patterns of sexual arousal. Results: When compared with premenopausal women, untreated postmenopausal women had significantly decreased areas of brain activation during both erotic and neutral stimulations. Administration of estradiol increased global brain-activation patterns during both visual stimulations, with erotic video viewing causing a limited increase in limbic system activation. Combined estradiol and testosterone therapy was associated with a greater activation of the central nervous system, with more limbic system activated during the erotic video. Brain-activation patterns of the postmenopausal women were similar to the premenopausal group only during the estradiol and testosterone treatment phase. Conclusions: Agonadal serum hormone levels result in globally decreased brain-activation patterns in postmenopausal women while viewing neutral and erotic videos. Administration of both estradiol and testosterone increase global brain activation, and both sex steroids are independently associated with enhanced limbic system response during erotic visual stimulation. Six surgically postmenopausal women underwent functional magnetic resonance imaging of the brain while viewing erotic videos while not on hormone therapy, after estrogen treatment, and after combined estrogen and testosterone treatment. Estrogen therapy resulted in increased brain activation compared with no hormone therapy with a further increase in the areas of activation with the addition of testosterone, suggesting a role for both hormones in sexual arousal.