NatureScienceSexual difference

Sex differences in brain

We often talk about “sex differences in brain”. In fact, there are a variety levels of sex differences including a slight difference that we can detect only after the careful examination of 100 males and 100 females, and an obvious and robust difference that anyone can see. The hypothalamus shows clear sex differences, which are determined by the hormonal environment during development. In other words, the developing brain has sensitivity to hormone, especially testosterone. We found that a transcription factor, PTF1a, is essential for acquiring the sensitivity to hormone milieu during development.
よく「脳の男女差」といわれますが、その中には、男100人と女100人で比べると平均値が少し違う程度のものから、男女で明瞭に差があるものまでさまざまあります。この明瞭な男女差は視床下部などに見られますが、この差は出生前後もしくは子宮内でのホルモン環境によって決まります。いいかえると、発生途中の脳はホルモン(テストステロン)感受性を持っています。このホルモン感受性の獲得に、PTF1aという転写因子が必須であることがわかりました。