Prolactin, a hormone that increases during pregnancy, regenerates myelin destroyed in mouse models of multiple sclerosis (MS). The results may explain why symptoms of MS sometimes abate during pregnancy.
Journal of Neuroscience, February 21
T. rex and other meat-eating dinosaurs had small genomes, on par with modern birds, which have about 1.45 billion bases (humans have about three billion). The finding counters a hypothesis that birds evolved and maintained smaller genomes to conserve energy for flight.
Nature, March 8
Out-of-body sensations may stem from a disturbance in the brain's arousal system, in which it would fail to make a proper transition from REM sleep (when dreams often occur) to wakefulness.
Neurology, March 6
Asteroid surfaces that have absorbed warming sunlight can reemit the heat when they move into the shade, thereby creating recoil and affecting an asteroid's rotation.
Science Express, March 8