Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transsexuals experience themselves as being of the opposite sex, despite having the biological characteristics of one sex. A crucial question resulting from a previous brain study in male-to-female transsexuals was whether the reported difference according to gender identity in the central part of the bed nucleus of the stria terminalis (BSTc) was based on a neuronal difference in the BSTc itself or just a reflection of a difference in vasoactive intestinal polypeptide innervation from the amygdala, which was used as a marker. Therefore, we determined in 42 subjects the number of somatostatin-expressing neurons in the BSTc in relation to sex, sexual orientation, gender identity, and past or present hormonal status. Regardless of sexual orientation, men had almost twice as many somatostatin neurons as women (P < 0.006). The number of neurons in the BSTc of male-to-female transsexuals was similar to that of the females (P = 0.83). In contrast, the neuron number of a female-to-male transsexual was found to be in the male range. Hormone treatment or sex hormone level variations in adulthood did not seem to have influenced BSTc neuron numbers. The present findings of somatostatin neuronal sex differences in the BSTc and its sex reversal in the transsexual brain clearly support the paradigm that in transsexuals sexual differentiation of the brain and genitals may go into opposite directions and point to a neurobiological basis of gender identity disorder.
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PMID:Male-to-female transsexuals have female neuron numbers in a limbic nucleus. 1084 93

Gonadal steroids have remarkable developmental effects on sex-dependent brain organization and behavior in animals. Presumably, fetal or neonatal gonadal steroids are also responsible for sexual differentiation of the human brain. A limbic structure of special interest in this regard is the sexually dimorphic central subdivision of the bed nucleus of the stria terminalis (BSTc), because its size has been related to the gender identity disorder transsexuality. To determine at what age the BSTc becomes sexually dimorphic, the BSTc volume in males and females was studied from midgestation into adulthood. Using vasoactive intestinal polypeptide and somatostatin immunocytochemical staining as markers, we found that the BSTc was larger and contains more neurons in men than in women. However, this difference became significant only in adulthood, showing that sexual differentiation of the human brain may extend into the adulthood. The unexpectedly late sexual differentiation of the BSTc is discussed in relation to sex differences in developmental, adolescent, and adult gonadal steroid levels.
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PMID:Sexual differentiation of the bed nucleus of the stria terminalis in humans may extend into adulthood. 1182 31