Why Unfamiliar Streets Become Familiar... Changes in Granule Cells

Granule Cells in the Hippocampus Play a Key Role in Spatial Memory
Place Cells That Encode Location Information Change to Support Spatial Memory
Memory-Related Network Modeling Advances Understanding of Brain Disorders Linked to Hippocampal Damage

[Asia Economy Reporter Junho Hwang] Everything feels unfamiliar when walking down a new street. You have to carefully watch each building and surrounding landmark to avoid getting lost. However, after walking the unfamiliar path a few times, you quickly remember the way. How does our brain become familiar with it?

On the 28th, Dr. S?bastien Royer’s research team at the Brain Science Operations Unit of the Korea Institute of Science and Technology revealed that granule cells in the hippocampus of our brain learn places through various neural networks including mossy cells. The research results were recently published in Nature Communications.

Spatial Learning Through Changes in Granule Cells

Recording Cell Activity During Treadmill Training

The hippocampus provides information about the surrounding environment and one’s own location, and functions to learn and remember new facts. It is also the first area to be damaged when brain diseases such as Alzheimer’s disease progress.

The research team observed brain cells in the dentate gyrus, where place information input to the hippocampus begins, to study the process of place cell formation while learning a new environment. They trained experimental mice on a treadmill, a spatial training device, for 27 days and observed changes in mossy cells and granule cells, which make up the dentate gyrus.

In particular, when observing granule cells, which have various characteristics related to place memory, place cells within granule cells placed in a new space represented information about the location of objects or distance information at regular intervals. As the space became familiar and learned, cells representing object location and distance information disappeared, and place cells representing specific locations gradually increased.

Providing Direction for Understanding and Treating Brain Diseases

Computer Model for Treadmill Training

The research team reproduced the gradual changes in cell activity due to learning through a competitive learning model, one of the neural network models, and revealed that mossy cells are involved in place memory through interaction with granule cells. Although mossy cells themselves did not show significant changes due to spatial learning, their activity plays a major role in the transformation of granule cells from representing object location information to spatial location memory.

Dr. Royer stated, "By greatly contributing to understanding the role of the hippocampus, this research not only advances AI-based neuroengineering but also provides new directions for understanding, treating, and preventing brain diseases related to hippocampal damage such as memory loss, Alzheimer’s, and cognitive impairment."

This content was produced with the assistance of AI translation services.