Danger Mouse: Deleting a gene transforms timid rodents into daredevils

By removing one gene from a mouse’s standard repertoire, scientists have turned a timid animal into an intrepid one.

Gleb Shumyatsky of Rutgers University in Piscataway, N.J., and his colleagues study the genetics that affect how animals remember scary stimuli and how they respond to fright. “Fear is definitely important when you think about the survival of an organism,” Shumyatsky says.