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Hi guys, to begin I just want to make a couple of things clear.
- This thread is NOT about discrimination of homosexuals.
- This thread is NOT about considering homosexuality as disease.
- This thread is for pure scientific discussion.
Well, let me begin by telling you that I'm a med student and a embriology assistant at my university and I'm not a native english speaker, so you may encounter some grammatical errors in the text, but you'll get the point.
This whole dilemma began two weeks ago, when my brother told my family that he is gay. It was quite a shock, not because of the fact of him being gay but because he doesn't fit the gay man stereotype. He's a big dude, loves sports, bearded, the true definition of what some call "manly man". We accepted him, of course, and I have to say I've never seen him happier.
But after a few days I began to think, was he always gay? Did he decided to be gay? Why now? These questions started lingering in my mind. So I went to talk with my him about it.
He told me that he always has been, for as long as he remembers. Nothing has changed about him, except for his sexuality (for us, not for him haha). So that got me even MORE questions. Why are some gay men that are like extremely feminine? Why are some gay women extremely masculine? Why are gay guys like my brother who don't appear to be gay? Why do some gay people feel like they are traped inside the other genders body and need to get medical treatment (sex change surgery, hormone therapy) and why others don't?And why are there women like that too? Why many species, whose main goal is to survive (actually this is every species main goal, it's literally in our DNA), has certain individuals who are the contrary to this?
So I decided to tackle all these matters from a scientific point of view? What if during the development of the lymbic system (the part of the brain which controles emotions, memory, sexual desire, etc.) something doesn't go as it should?
So after I thought of this I told myself I couldn't be the first one to ask myself these questions. And of course I wasn't in a world with 7 billion people so thanks to the magical power of the internet I managed to get a cool text about the subject. I took some paragraphs which I thought were the most interesting, still I'm leaving the link (please don't take the text as discriminatory, it's merely scientific, it refers to homosexuality as an anomaly in brain developement because seen from a medical point of view it is, still doesn't mean it's moraly wrong).
"..the body and the brain first become sexually differentiated at about the third fetal month. Prior to this age, although genetically male or female, the fetus is physically/sexually-neutral. With the formation of the testes, and the secretion of testicular androgen, target tissues in the spinal cord, brainstem, and cerebrum become activated and transformed into "male" neurons, and form "male" patterns of neural development and neural circuitry, including the pattern of dendritic interconnections between target tissues in the hypothalamus, amygdala, hippocampus, cingulate gyrus, and the bed nucleus of the stria terminals and thus the septal nuclei as well as the amygdala (Bleier et al. 1982; Bubenik & Brown, 1973; Dorner, 1976; Gorski et al. 1978; Nishizuka & Arai, 1981; Rainbow et al. 1982; Raisman & Field, 1971, 1973). It is also well established that the presence (or absence) of testosterone directly effects and determines sexual and cognitive sex differences in mammals including humans (Barnett & Meck, 1990; Beatty, 1992; Collaer & Hines 1995; Dawson et al. 1975; Joseph et al., 1978; Masica et al., 1969; Resnick & Berenbaum 1982).
Presumably, these effects are initially triggered through the differential action of testosterone within target brain areas thus altering neuronal genomic expression (Breedlove 1992; McCarthy 1994 for review). By acting directly on target cell DNA, testosterone (or lack therefore) directly effects neural migration and proliferation vs programmed cell death, and thus cell growth, differentiation, density and myelination (Breedlove 1992; McCarthy 1994; Tobet & Fox 1992). In consequence, a "male" rather than a "female" brain is produced.
The effects of fetal androgens, however, are controlled by a variety of genetic mechanisms which modulate receptor topography and the density of receptor populations which differ during different stages of development and as a function of gender. For example, the genetic sex of the target tissue appears to effect receptor affinity for steroid binding, such as through the secretion of alpha-fetoprotein (Raynaud, Mercier-Bodard & Balieu 1971). These alpha-fetoproteins bind to all circulating estrogens and thus changes their external chemical configuration so that it cannot be recognized by neural receptors (Toran-Allerand 1986). Their chemical configuration is altered and they cannot be taken up by steroid sensitive neurons. Thus these protein act to suppress the influences of these hormones by making them unrecognizable so that they cannot act on the DNA of target neural tissue. Hence, if for any reason there is a failure to produce alpha fetal proteins, females may become masculinized by their own estrogen secretions or the secretions of androgens by the adrenals.
Testosterone however, does not act directly on the genomes of target tissues. Rather, fetal androgens must converted into dihydrotestosterone and into estradiol by an enzyme referred to as aromatase. Aromatase enables fetal androgens to bind to estrogen as well as to testosterone receptors (McCarthy 1994), whereas dihydrotestosterone acts selectively on testosterone receptors. Again, females are protected in this regard by the secretion of alpha-fetoprotein (Raynaud, Mercier-Bodard & Balieu 1971). However, if for any reason these fetal androgens fail to become converted, or if they are prevented from acting on target neural tissue, the female pattern of sexual differentiation will ensue. Although genetically male, the individual may be born with a "homosexual" brain.
Fetal stress may play a significant role in the failure of the male pattern of neural differentiation to unfold, and may well play a significant role in the etiology of homosexuality. Specifically, chronic stress can alter the binding of testosterone, and can prevent testosterone from binding with hypothalamic and amygdala neurons responsible for sexual behavior (Raab & Haedenkamp, 1981). If the fetus is subject to considerable stress, or if "mother" is in an abusive relationship or subject to other profound stress, the secretion of stress-steroids may effect the sexual differentiation and the development of the limbic system and induce the female pattern of neural development. That is, as these stress-steroids, e.g., cortisol and aldosterone, are not true androgens, rather than inducing a male pattern, they may block the reception and binding of fetal testosterone, thereby inducing the female developmental pattern. In fact, the secretion of cortisol and aldosterone--particularly if prolonged--can reduce the secretion of gonadropins (Moberg, 1985), which would also interfere with male sexual behavior and the development of the male pattern of neural development.
As noted, it has been shown that the ventromedial and anterior nuclei of the hypothalamus of male homosexuals demonstrate the female pattern of development (Levay, 1991; Swaab, 1990); sex-specific patterns which may have been induced by stress. If these stress induced steroidal changes also negatively impact the amygdala, affected individuals may not only become homosexual, or sexually and emotionally abnormal."
http://brainmind.com/AbnormalBrainDevelopment.html
So, thats all. Hope you guys like it and I wanna see what you think about this.