Dan Robitzski

Researchers find that an increased heart rate can induce anxiety in mice, given the right context. It's the first evidence that the heart can directly influence the brain -- a finding that scientists say could lead to better PTSD treatments in the future.

Synthetic variations of squalene, which is used to boost immune responses, could make vaccines more effective while reducing fisheries for struggling sharks.

An experimental new contraceptive method temporarily renders male mice infertile by immobilizing their sperm. While it will be years before human tests begin, the drug blocked 100 percent of pregnancies in treated mice.