How emotionally charged events leave their mark on memory
Researchers have uncovered new evidence in mice that may explain how emotionally charged situations can leave such a powerful mark on our memories. Surges of the stress hormone norepinephrine (also known as noradrenaline) that often accompany strong emotions spark a series of molecular events that ultimately strengthen the connections between neurons, the team reports in the October 5, 2007, issue of the journal Cell . “This phenomenon is something everyone can identify with,” said Roberto Malinow of the Cold Spring Harbor Laboratory in New York. “You can probably remember where you were when you heard about 9/11, but you probably don’t know where you were on 9/10. We've identified one mechanism that may underlie this effect.” The parts of the brain where memories are stored need to distinguish between significant experiences and those that carry less importance, giving priority to the transformation of the former into long-term memory, the researchers explained. One factor th...