Key role identified for nervous system in severe allergic shock

A key feature of the severe allergic reaction known as anaphylaxis is an abrupt drop in blood pressure and body temperature, causing people to faint and, if untreated, potentially die. That response has long been attributed to a sudden dilation and leakage of blood vessels. But in a study using mice, researchers have found that this response, especially body temperature drop, requires an additional mechanism -- the nervous system.