Caught in the Act

Credit: ZEISS Microscopy

Imagine seeing for the first time a mistake as it unfolds in a false memory. UT Austin neuroscientists made just such an observation for the first time during a memory trial.

Laura Colgin, associate professor of neuroscience, and her team recorded electrical impulses in the brains of rats in and out of mazes, as the rats tried to remember where food rewards could be found.

“We could see the memories activating,” Colgin said. “It’s like dominoes falling. One cell activates and then the next fires.”

These cells, called place cells, are associated with memories involving spatial relationships and locations and are found in the hippocampus, a section of the brain where animals including humans store most of their memories. It is also a region of the brain that experiences degeneration in patients with Alzheimer’s and related memory disorders.

When a correct memory is retrieved, the cells activate in a predictable pattern. The scientists discovered that, in the midst of retrieving a false memory, that same pattern of cells activate — just a lot slower. Additionally, researchers found that the rats that remembered correctly where the food was were those that accessed the memory before they entered the maze. The rats that got it wrong did not access the memory until entering the maze.

One of the Colgin lab’s long-term goals is to contribute to understanding memory formation and retrieval enough that one day, lost memories could be accessed even by people with memory disorders with the help of brain-computer interface technology.