Oral Presentation The Annual Scientific Meeting of the Endocrine Society of Australia and the Society for Reproductive Biology 2014

Does anti-Müllerian hormone retard and shape the development of the male brain? (#164)

Ian McLennan 1
  1. University of Otago, Dunedin, OTAGO, New Zealand

The testes secrete high levels of Anti-Müllerian hormone (AMH) from early in the embryonic period until the onset of puberty.  The first actions of AMH are to trigger the degeneration of the uterine precursor, after which AMH contributes to the virilisation of various organs.  All neurons express the AMH-specific receptor, identifying the developing brain as a prime site for the effects of AMH.  AMH-/- male mice have a male sexual preference, but some of their brain nuclei have a female form, and they lack the male bias in exploratory behaviour.  They also lack an interest in social pheromones, suggesting that AMH may be necessary for normal socialisation of male pups.  Boys with high levels of AMH are short in stature relative to their parents, and their drawings are relatively immature for their age.  This suggests that testicular AMH slows the speed of human male development, causing boys to be less mature than similarly aged girls.  Slow speed of development across the taxa is protective against subtle developmental defects.  This raises the possibility that a boy’s AMH levels may be a generalised risk/protective factor for disorders of brain development.  Consistent with this, the breadth of symptoms in boys with an autistic spectrum disorder inversely correlates with their plasma levels of AMH.  The discovery that AMH has cryptic functions brings into sharp focus the fact that the embryonic testes secrete multiple protein hormones, whose functions have yet to be explored.