IN our first review of the “grey matter studies,” which the LGBT (Lesbian, Gay, Bisexual, Transgender) community used to claim that gender identity has a biological basis, we talked about a study on the bed of nucleus of the stria terminalis (BNST).
This week, we proceed with the evidence that researchers Aruna Saraswat, Jamie Weinand and Joshua Safer presented in the 2015 Endocrine Practice issue, which involved the uncinated nucleus, particularly the interstitial nucleus of the anterior hypothalamus 3 (INAH 3). It pertained to the Garcia-Falgueras and Swaab study published in 2008 in the Brain journal, which investigated the grey matter of dead persons, such as heterosexual males and females (as controls), castrated males (as a control), transsexual male-to-females (MTF) and female-to-males (FTM).
The INAH 3 is the frontal area of the hypothalamus that is considered sexually dimorphic or looks differently in the male and the female sex. It is part of the uncinated nucleus, a nerve nucleus that consists of two smaller nuclear parts, the INAH 3 subnucleus and the INAH 4 subnucleus. It connects or projects its nerve fibers to the BNST.
The study observed that the quantity and volume of neurons in the INAH 3 subnuclei of the MTF transsexuals appeared in its stained profile under the microscope similar to the females, while that of the FTM transsexuals appeared within the range of the male persons on the same criteria. On the surface, this means that the INAH 3 profile in MTF transsexuals looked like that of the females and that of the FTM transsexuals similar to the males’.
Since the INAH 3 dimorphism also occurs during adulthood, these findings can argue validly that gender identity has biological bases from the INAH 3 findings mentioned; that is, if no extraneous chemical interventions occurred, which will introduce doubt into the presumed natural and normal shift of the sexual identity in the dimorphic INAH 3 subnuclei.
The problem is, in both FTM and MTF subjects, hormonal intervention occurred, which may have caused a permanent shift of the INAH 3 characteristic from male to female and female to male. The MTF transsexuals, for instance, used estrogen hormones for a long period of time before and after their transsexual surgery. Conversely, the FTM subjects used testosterone hormones for a long period although they ceased using it three years before their deaths.
This information makes it uncertain to conclude that the sex identity shift in the INAH 3 profile was a natural development even. Thus, although the microscopic findings were clear, the attribution power of these findings is weak and uncertain. Factor into these findings the commonly observed behavior change in gender orientation among transgenders during their early age, the uncertainty increases.