INAH 3
Encyclopedia
The INAH 3 is the third interstitial nucleus
of the anterior hypothalamus
. Part of the sexually dimorphic nucleus
, the INAH 3 is significantly larger in males than in females irrespective of age. Homologues of the INAH 3 have been observed taking a direct role in sexual behavior in rhesus monkeys, sheep, and rats.
Research
A scientific paper authored by Simon LeVay
and published in the journal Science
suggests that the region is an important biological substrate with regards to sexual orientation
. This article reported the INAH 3 to be smaller on average in homosexual men than in heterosexual men, and in fact has approximately the same size in homosexual men as in heterosexual women. This study was criticized as having various methodological flaws.
A study by Dick Swaab similarly found the INAH 3 to be smaller in male-to-female transsexual people than in control males, and similar to control females.
Nucleus (neuroanatomy)
In neuroanatomy, a nucleus is a brain structure consisting of a relatively compact cluster of neurons. It is one of the two most common forms of nerve cell organization, the other being layered structures such as the cerebral cortex or cerebellar cortex. In anatomical sections, a nucleus shows up...
of the anterior hypothalamus
Hypothalamus
The Hypothalamus is a portion of the brain that contains a number of small nuclei with a variety of functions...
. Part of the sexually dimorphic nucleus
Sexually dimorphic nucleus
Sexually dimorphic nucleus is a cluster of cells located in the preoptic area of hypothalamus of the brain that is believed to be related to sexual behavior in animals. The volume of SDN is significantly larger in males than in females, caused mainly by greater cell number and larger cell size,...
, the INAH 3 is significantly larger in males than in females irrespective of age. Homologues of the INAH 3 have been observed taking a direct role in sexual behavior in rhesus monkeys, sheep, and rats.
Research
A scientific paper authored by Simon LeVay
Simon LeVay
Simon LeVay is a British-American neuroscientist. He is known for his studies about brain structures and sexual orientation.-Personal life:LeVay was born on August 28, 1943 in Oxford, England...
and published in the journal Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
suggests that the region is an important biological substrate with regards to sexual orientation
Sexual orientation
Sexual orientation describes a pattern of emotional, romantic, or sexual attractions to the opposite sex, the same sex, both, or neither, and the genders that accompany them. By the convention of organized researchers, these attractions are subsumed under heterosexuality, homosexuality,...
. This article reported the INAH 3 to be smaller on average in homosexual men than in heterosexual men, and in fact has approximately the same size in homosexual men as in heterosexual women. This study was criticized as having various methodological flaws.
A study by Dick Swaab similarly found the INAH 3 to be smaller in male-to-female transsexual people than in control males, and similar to control females.