"For the first time, we've found that two different areas of the brain share the function of storing and remembering events for short-term memory," said Sam Deadwyler, Ph.D., lead researcher. "These new findings broaden our understanding of how memory works."
Deadwyler and co-investigator Robert Hampson, Ph.D., showed that the hippocampus, a structure long believed to be important for short-term memory, shares this function with another adjacent brain area, the subiculum. The research, reported in the current issue of Neuron, shows that both structures are required to process information correctly.
Knowing more about memory and what goes wrong in conditions such as Alzheimer's disease could lead to more sensitive tests for early diagnosis, as well as new drugs to enhance and recover memory, said Deadwyler. In addition, the findings that two brain areas act together to establish and retrieve short-term memories suggests the possibility that humans could be retrained to use one area if the other is damaged or diseased.
"Surprisingly, we found that the shortest memories were controlled almost exclusively by the subiculum, which is exactly opposite from what was previously believed," said Deadwyler. "For the first 10 to 15 seconds of the task used to examine this in rats, we found that the memory function of the hippocampus actually shuts off."
Using multiple electrodes smaller than the size of a human hair, the researchers recorded activity in the hippocampus and subiculum as rats performed a memory task. The results showed that both brain structures "encode" or "remember" information, but they do it at different times.
For the memory task, rats were randomly presented either a "right" of "left" lever. With f
Contact: Karen Richardson
Wake Forest University Baptist Medical Center