Brain activation patterns associated with sexual orientation in homosexual male and female: a case study with 3.0T fMRI

Gwang-Won Kim, Gwang-Woo Jeong, Jong-Chul Yang

.

DOI: 10.4236/jbise.2011.43027                

Abstract

This study was performed to clarify the sexual orien-tation in a 19-year-old homosexual male and a 20-year-old homosexual female by using a functional magnetic resonance imaging (fMRI) with viewing male and female erotic nude pictures. The sex hor-mone levels of the homosexual male and female were in the normal range of healthy heterosexual males and females, respectively. In both homosexuals more significant brain activities were observed while view-ing the nude pictures of the same genetic sex than those of the opposite sex in the frontal cortex, parietal cortex, occipital cortex, anterior cingulate gyrus, amygdala, midbrain, hippocampus, orbitofrontal cortex, parahippocampal gyrus, thalamus, globus pallidus, and putamen, which are known to be re-sponsive to sexual arousal. The homosexual male and female showed a tendency toward higher sexual arousal to the same genetic sex as comparison with the opposite sex. This finding may be useful to un-derstand the different neural mechanisms on sexual arousal in homosexuals.

Keywords

Sexual orientation; Homosexual male; Homosexual female; Functional magnetic resonance imaging (fMRI)

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Vocks, S., Stahn, C., Loenser, K. and Legenbauer, T. (2009) Eating and body image disturbances in male-to- female and female-to-male transsexuals. Archives of Sexual Behavior, 38, 364-377. doi:10.1007/s10508-008-9424-z
[2]	Safron, A., Barch, B., Bailey, J.M., Gitelman, D.R., Parrish, T.B. and Reber, P.J. (2007) Neural correlates of sexual arousal in homosexual and heterosexual men. Be- havioral Neuroscience, 121, 237-248. doi:10.1037/0735-7044.121.2.237
[3]	Swaab, D.F. (2004) Sexual differentiation of the human brain: Relevance for gender identity, transsexualism and sexual orientation. Gynecological Endocrinology, 19, 301-312. doi:10.1080/09513590400018231
[4]	Negri-Cesi, P., Colciago, A., Pravettoni, A., Casati, L., Conti, L. and Celotti, F. (2008) Sexual differentiation of the rodent hypothalamus: Hormonal and environmental influences. The Journal of Steroid Biochemistry and Mo- lecular Biology, 109, 294-299. doi:10.1016/j.jsbmb.2008.03.003
[5]	Green Cross Reference Lab (2007) Sex Hormones in Green cross reference lab guidebook, Yongin, Republic of Korea, 201-224.
[6]	Ponseti, J., Bosinski, H.A., Wolff, S., Peller, M., Jansen, O., Mehdorn, H.M., Büchel, C. and Siebner, H.R. (2006) A functional endophenotype for sexual orientation in humans. Neuroimage, 33, 825-833. doi:10.1016/j.neuroimage.2006.08.002
[7]	Paul, T., Schiffer, B., Zwarg, T., Krüger, T.H., Karama, S., Schedlowski, M., Forsting, M. and Gizewski, E.R. (2008) Brain response to visual sexual stimuli in hetero-sexual and homosexual males. Human Brain Mapping, 29, 726-735. doi:10.1002/hbm.20435
[8]	Jeong, G.W., Park, K., Youn, G., Kang, H.K., Kim, H.J., Seo, J.J. and Ryu, S.B. (2005) Assessment of cerebro- cortical regions associated with sexual arousal in premeno- pausal and menopausal women by using BOLD-based functional MRI. The Journal of Sexual Medicine, 2, 645-651. doi:10.1111/j.1743-6109.2005.00134.x
[9]	Mouras, H., Stoléru, S., Bittoun, J., Glutron, D., Pé- légrini-Issac, M., Paradis, A.L. and Burnod, Y. (2003) Brain processing of visual sexual stimuli in healthy men: A functional magnetic resonance imaging study. Neuroi- mage, 20, 855-869. doi:10.1016/S1053-8119(03)00408-7
[10]	Karama, S., Lecours, A.R., Leroux, J.M., Bourgouin, P., Beaudoin, G., Joubert, S. and Beauregard, M. (2002) Areas of brain activation in males and females during viewing of erotic film excerpts. Human Brain Mapping, 16, 1-13. doi:10.1002/hbm.10014