Estradiol Masculinizes Hypothalamus?

Tara Marchand t_marcha at
Mon Mar 18 00:57:29 EST 1996

trpede at (Pentti Degerstr|m) wrote:
: Alpha-fetoprotein binds estrogen so only testosterone enters the
: cell (during critical period in pregnancy) and is aromatized to estradiol
: after entering. Could defects in this mechanism be the cause for 
: homosexual behavior?

First of all, there's homosexual behavior, and there's a homosexual sexual
orientation--this is an important distinction.  And it's important to
specify whether you're talking about female or male homosexuality.  I
assume you're talking about the latter.  In that case, if some disturbance
in aromatization of estradiol to testosterone caused male homosexuality,
one would expect to see a brain that looks like that of a female--that is,
structures would not have been masculinized.  Certain differences in brain
structure between gay and straight men have been pointed out (e.g., INAH-3
[the third interstitial nucleus of the anterior hypothalamus], which was
studied in controversial research by Simon LeVay), but this area is still
wide-open, and different studies have had conflicting results.  Also, lest
I sound like a complete biological determinist, I must argue that
environmental influences undoubtedly play roles in affecting sexual
orientation.  (The "nature-nurture" dichotomy is a false one.)

Tara R. Marchand
t_marcha at

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