/cuteboys/ - Boypussy

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0083947#s5

http://archive.vn/DzPao

Abstract

>Gender identity disorder (GID) refers to transsexual individuals who feel that their assigned biological gender is incongruent with their gender identity and this cannot be explained by any physical intersex condition. There is growing scientific interest in the last decades in studying the neuroanatomy and brain functions of transsexual individuals to better understand both the neuroanatomical features of transsexualism and the background of gender identity. So far, results are inconclusive but in general, transsexualism has been associated with a distinct neuroanatomical pattern. Studies mainly focused on male to female (MTF) transsexuals and there is scarcity of data acquired on female to male (FTM) transsexuals. Thus, our aim was to analyze structural MRI data with voxel based morphometry (VBM) obtained from both FTM and MTF transsexuals (n = 17) and compare them to the data of 18 age matched healthy control subjects (both males and females). We found differences in the regional grey matter (GM) structure of transsexual compared with control subjects, independent from their biological gender, in the cerebellum, the left angular gyrus and in the left inferior parietal lobule. Additionally, our findings showed that in several brain areas, regarding their GM volume, transsexual subjects did not differ significantly from controls sharing their gender identity but were different from those sharing their biological gender (areas in the left and right precentral gyri, the left postcentral gyrus, the left posterior cingulate, precuneus and calcarinus, the right cuneus, the right fusiform, lingual, middle and inferior occipital, and inferior temporal gyri). These results support the notion that structural brain differences exist between transsexual and healthy control subjects and that majority of these structural differences are dependent on the biological gender.

Introduction

>Transsexualism is a heterogenous condition both in its manifestation and etiology. There are numerous chromosomal abnormalities or well-defined biological causes that can lie behind the incongruence between an individual's biological gender (i.e. that based on the sex chromosomes and/or the manifestation of the sexual organs) and gender identity (i.e., someone's sense and perception of being male or female). However, there is a group of individuals who do not show such known genetic or somatic abnormality and yet experience strong incongruency between their assigned biological gender and their gender identity. In the Diagnostic and Statistic Manual of Mental Disorders 4th edition - Text Revision [1] this is referred as Gender Identity Disorder (GID). GID is characterized by a long-standing and strong feeling of being a member of another gender, long-standing distress about the assigned gender and feeling of incongruity with the assigned gender-roles causing significant clinical discomfort and impairment in both the individual's social and professional life and in other life areas. Based on DSM-IV-TR, GID cannot be diagnosed if transgender experiences are associated with any physical intersex conditions.

>The background of transsexualism has been the topic of debate for decades. Recently, mainly early developmental disturbances have been suggested by the pertinent literature [2]. According to a recent review about the sexual differentiation of the human brain, transsexualism might be the result of the fact that the development of the sexual organs in the fetal life occurs well before the sexual differentiation of the brain. Thus, if something disturbs the sexual differentiation of the brain, the fetus already has sexual organs according to his/her assigned sex, while his/her brain might develop differently [2]. These authors suggest that the disturbance of the testosterone surge that masculinize the fetal brain might be at the background of GID in certain cases. Furthermore, they emphasize that there is no compelling evidence that postnatal environmental factors play a crucial role in sexual orientation and gender identity [2]. The theories about the neurobiological background of GID were partly based on earlier neuroanatomical findings of the same group, Swaab and collegues. This group described differences in the brain structure of Male to Female (MTF) and Female to Male (FTM) transgender subjects and controls (post mortem) in regions of the brain that showed sex differences regarding their size [3]. Specifically, they found that the size and the number of neurons in the bed nucleus of striata terminalis (BSTc) and the third interstitial nucleus of the anterior hypothalamus (INAH-3) of MTF transgender patients were typical for the size and neuron numbers found generally in females [3]–[5].

>…