Cited research: Neuron 66, 260–272 (2010)

In many vertebrates, male sexual and territorial behaviours are regulated by testosterone and oestrogen in the brain. Nirao Shah at the University of California, San Francisco, and his colleagues have found that, in male mice, testosterone controls the extent of these behaviours, but not their programming during development. The authors confirm previous findings that this programming is mediated by oestrogen, which in the male brain is derived from testosterone.

The authors discovered that the androgen receptor, which binds testosterone, is not abundant in the brains of developing male mice, but that oestrogen results in greater expression of this receptor later on in males than in females. Mice in which the gene for this receptor was deleted in the nervous system still displayed typical sexual and territorial behaviours, but to a lesser extent.