Biology and sexual orientation INAH3 weight for the heterosexual male brains was significantly larger than for the heterosexual female brains, while the results for the gay male group were between those of the other two groups but not quite significantly different from either. The neuron count also found a male-female difference in INAH3, but found no trend related to sexual orientation. A 2010 study, Garcia-Falgueras and Swaab asserted that "the fetal brain develops during the intrauterine period in the male direction through a direct action of testosterone on the developing nerve cells, or in the female direction through the absence of this hormone surge.
Hormone replacement therapy sexuality can be a critical issue in determining whether one begins to experience changes in their sexual response cycle. Both age — and menopause-related events can affect the integrity of a woman’s biological systems involved in the sexual response cycle, which include hormone environment, neuro-muscular substrates, and vascular supplies. Therefore, it can be appropriate to make use of HRT, especially in women with low or declining quality of life due to sexual difficulties. Current research that has examined the impact of menopause on women’s self-reported sexual satisfaction indicates that 50.3% of women experience some sexual disturbance in one of five