A new very nervous mouse could help lead to new treatments for those with anxiety and eating disorders. Researchers at the University of Michegan discovered that mice lacking a particular biochemical showed increased anxiety-like behaviours, they write in the current US Proceedings of the National Academy of Sciences . The missing substance connects in turn with an important hormone that helps control the body's behavioural, hormonal and immune responses to stress. The results may be valuable for testing anti-anxiety drugs.