Emotion and scent `create lasting memories`

Emotion and scent create lasting memories even in a sleeping brain, a new study has suggested. A team at the Duke University has found that the part of the brain that processes scents is indeed a key component of forming long-term memories, especially involving other individuals, a science journal reported. "We can all relate to the experience of walking into a room and smelling something that sparks a vivid, emotional memory about a family member from years or even decades ago. This research sought to understand that phenomenon on a cellular level," lead author Stephen Shea said. In their study, the researchers examined how strong memories are formed by creating new memories in the minds of mice while under sedation and monitoring their response to a memory-inducing stimulus afterwards, when they were awake. They created memories by stimulating the release of noradrenaline, a chemical present in the body during strong emotional events ranging from excitement to fear. The team then administered anaesthesia to a mouse and stimulated the release of noradrenaline with an electrode while wafting the scent of either food or the urine of another mouse under the nose. "In essence, we recreated the chemical reaction that would occur when the mouse experiences a social event, such as giving birth," Shea said.