Researchers Study The Mouse Brain To Learn About The Memory Center

Some people have better memories than others, able to recall also the facts and figures with ease. Researchers have been conducting investigations using mouse brains to try and learn more about how the visual cortex stores and remembers individual images. The team found that the brain's memory center is needed to recognize image sequences, but not single sites.

Mice used in the study are unable to recognize image sequences without guidance from the hippocampus. The study was conducted at MIT to learn how the mammalian brain remembers what it sees. Researchers showed that while individual images are stored in the visual cortex, the ability to recognize the sequence of sites depends critically on guidance from the hippocampus.

The hippocampus is a deeper structure strongly associated with memory, but it's unclear exactly how it impacts memory. Since the research suggests, the hippocampus isn't needed for basic storage of images, such as defining the chronological relationship images might have, neuroscientists are closer to understanding how the brain coordinates long-term visual memory across key regions.

The research gives the opportunity to understand how the hippocampus contributes to memory storage in the cortex in a concrete way. The lead author of the study, Peter Finnie, says that the hippocampus influences how images are stored in the cortex if they have a sequential relationship.

Finnie also says the team has discovered that the visual cortex seems to be involved in encoding both very simple visual stimuli and temporal sequences. Still, the hippocampus is selectively involved in how that sequence is stored. The research required the team to train two mice with two forms of visual recognition memory discovered in the laboratory. Those two forms include stimulus selective response plasticity and visual sequence plasticity.

To test how the brain stored images and learn about the role of the hippocampus, they chemically removed large portions of the structure in a group of mice and search for differences between the groups in electrical responses for each kind of recognition memory. Mice without the hippocampus perform equally well in stimulus selective response suggesting that type of memory doesn't require the hippocampus. However, visual sequence plasticity did not occur without an intact hippocampus.