|Younghee Seo1;Bumseok Jeong1;Ji-Woong Kim2; and Jeewook Choi3;
1;Department of Psychiatry, Eulji University College of Medicine, Daejeon,
2;Department of Psychiatry, College of Medical Science, Kongyang University, Daejeon,
3;Department of Psychiatry, Daejeon St. Mary's Hospital, The Catholic University of KoreaCollege of Medicine, Daejeon, Korea
Many studies have showed that excess or lack of sexual hormones, such as prolactin and testosterone, induced the sexual dysfunction in humans. Little, however, is known about the role of sexual hormones showing normal range in, especially, the basal state unexposed to any sexual stimulation. We hypothesized sexual hormones in the basal state may affect sexual behavior.
Methods : We investigated the association of the sexual hormones level in the basal hormonal state before visual sexual stimulation with the sexual response-related brain activity during the stimulation. Twelve heterosexual men were recorded the functional MRI signals of their brain activation elicited by passive viewing erotic (ERO), happy-faced (HA) couple, food and nature pictures. Both plasma prolacitn and testosterone concentrations were measured before functional MR scanning. A voxel wise regression analyses were performed to investigate the relationship between the concentration of sexual hormones in basal state and brain activity elicited by ERO minus HA, not food minus nature, contrast.
Results : The plasma concentration of prolactin in basal state showed positive association with the activity of the brain involving cognitive component of sexual behavior including the left middle frontal gyrus, paracingulate/superior frontal/anterior cingulate gyri, bilateral parietal lobule, right angular, bilateral precuneus and right cerebellum. Testosterone in basal state was positively associated with the brain activity of the bilateral supplementary motor area which related with motivational component of sexual behavior.
Conclusion : Our results suggested sexual hormones in basal state may have their specific target regions or network associated with sexual response.
Prolactin;Testosterone;Sexual behavior;Magnetic resonance imaging;Dopamine.