that there is still no consensus as and when they are formed responsible for gender identity in most animal brain structures (hypothalamus and amygdala) (if children are born like this or it develop at puberty, or both), there is consensus that these structures in the brain (hypothalamus) has structural and physiological differences between heterosexual men, gay men, transgender male to female, female to male transsexual, heterosexual women and homosexual women, regarding sexual identity and sexual attraction. New evidence indicates that sexual differentiation of the human brain occurs during fetal and neonatal development, and planning our gender identity and our sense of being male or female, as well as our sexual orientation as heterosexual, homosexual, or bisexual. The sexual differentiation process is accompanied by many structural and functional differences between these groups brain. Garcia-Falgueras and Swaab said in a summary of his 2010 study, "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. Accordingly, our gender identity (the conviction of belonging to the male or female gender) and sexual orientation are programmed or organized into our brain structures when we are still in the womb. there is no indication that the social environment after birth has an effect on gender identity or over sexual orientation. "In previous studies, The Savic laboratory detected a differentiation of the anterior hypothalamus in heterosexual men and heterosexual women, and an almost inverted, atypical in homosexual men and homosexual women. The hypothalamus, which is a small region of the brain located in the anterior commissure is involved in many different functions, including reproduction. These observations raised several issues, one of which was whether the described sexual dimorphism could be atypical in homosexual individuals, even with respect to factors not directly associated with reproduction. In a recent article, Savic and Lindstro reported that hemispheric relations, as well as patterns of connectivity with the amygdala, are atypical in homosexual individuals, displaying patterns more similar to heterosexual women than heterosexual men, and homosexual women exhibit similar patterns more like heterosexual men than heterosexual women (1, 2). The volumes of four groups of cells in this region (interstitial nuclei of the anterioror hypothalamus, or INAH 1, 2, 3 and 4, were measured in postmortem tissue from three groups of subjects: women, men who were heterosexual during their lifetime, and known to be homosexual men. No differences were found among the volumes of the cochlear nuclei of the hypothalamus INAH 1, 2 or 4 But the sub-nucleus INHA 3 was more than twice as large in heterosexual men than in women. It was also, however, more than twice as large in heterosexual men as in homosexual. This finding indicates that INAH 3 is dimorphic with sexual orientation, at least in men, and suggests that sexual orientation has a biological features. It was first demonstrated that the volume and number of neurons in the brain in the interstitial nucleus of the anterior hypothalamus 3 (INAH3) of male to