Testosterone is the executive that barks out orders to masculinize the fetal brain during pregnancy, but little is known about the underlings who scurry around to implement them. One such signal is prostaglandin-E2 (PGE2), reports a paper in the June issue of Nature Neuroscience, because drugs like aspirin that block its synthesis can interfere with brain masculinization and later male sexual behavior in rats. If this is also true in humans (which is not yet known), then there may be cause for concern about the widespread use of drugs such as aspirin and acetaminophen (commonly sold as Tylenol or Paracetemol) by pregnant women.
The authors report that male rats exposed during pregnancy or as newborns to cyclo-oxygenase inhibitors, which block the synthesis of PGE2, show a distinct dampening of copulatory behavior in adulthood, as might occur from a reduced sex drive. They also have a reduced number of dendritic spines on neurons in a brain region known to differ between males and females, making their brains look more female as well. Female rats injected with PGE2 show male-like copulatory behavior, and have more masculine brains than normal females. These unexpected results reinforce the conservative advice that it is prudent for women to avoid unnecessary medication during pregnancy.
An accompanying News and Views from Marc Breedlove and colleagues explains the significance of the paper. In the June editorial, Charles Jennings describes a longitudinal study already underway in the UK that may soon provide data to determine whether this finding generalizes to humans.
Margaret McCarthy (University of Maryland, Baltimore, MD, USA)
Tel: +1 410 706 2655, E-mail: firstname.lastname@example.org
News and Views author:
S. Marc Breedlove (Michigan State University, East Lansing, MI, USA)
Tel: +1 517 355 1749, E-mail: email@example.com
Also available online.
(C) Nature Neuroscience press release.
Message posted by: Trevor M. D'Souza