Scientists at Emory's Yerkes National Primate Research Center have achieved some insight into how fleeting experiences become memories in the brain. Their experimental system could be a way to test or refine treatments aimed at enhancing learning and memory, or interfering with troubling memories. The results were published in the Journal of Neuroscience. The researchers set up a system where rats were exposed to a light followed by a mild shock. A single light-shock event isn't enough to make the rat afraid of the light, but a repeat of the pairing of the light and shock is, even a few days later. "I describe this effect as 'priming'," says the first author of the paper, postdoctoral fellow Ryan Parsons. "The animal experiences all sorts of things, and has to sort out what's important. If something happens just once, it doesn't register. But twice, and the animal remembers." Parsons worked with Michael Davis, Robert W. Woodruff professor of psychiatry and behavioral sciences at Emory's School of Medicine, who studies the molecular basis for fear memory. Even though a robust fear memory was not formed after the first priming event, at that point Parsons could already detect chemical changes in the amygdala, part of the brain critical for fear responses. Long-term memory formation could be blocked...
