From News at Otago:
Otago neuroscientists reveal mechanism crucial to moulding male brains
Wednesday, 12 November 2014
Otago researchers have discovered that neural circuitry they previously showed was vital to triggering ovulation and maintaining fertility also plays a key role in moulding the male brain.
In new research appearing in the Journal of Neuroscience, a team led by Professor Allan Herbison shows that male-specific signalling in the Gonadotropin-releasing hormone (GnRH) neurons of new-born mice is crucial to generating a testosterone surge that occurs up to five hours after birth.
This brief but powerful increase in testosterone blood levels, which only takes place in males, is known to cause their brains to develop differently to females.
Among other effects, these brain differences are implicated in the patterns of neurological disorders that men and women suffer.
Professor Herbison says that sex differences in brain function are established during the later stages of foetal development and around birth, but the actual cellular mechanisms underlying these important actions remained unknown.
Through a series of investigations in mice, he and his colleagues have now shown that a small group of GnRH neurons in the brain’s hypothalamus become active only in new-born males, and not females.
Additionally, they found that a small population of kisspeptin neurons also appear at this time, once again only in males. Kisspeptin is a small protein that potently stimulates GnRH neurons. Last year Professor Herbison and colleagues published a landmark study detailing how it acts as a master controller of reproduction.