Large environments reveal the statistical structure governing hippocampal representations

Abstract

Nerve cells displaying extra large spaces Rats use brain cells called “place” cells to figure out where they are. Rich et al. used mazes or tracks many meters long—the size of rats' ranges in the wild—to investigate how rats represent a very large environment or extended experience in their brain. As novel environments became larger and larger, the rats' brains recruited new place cells. However, no matter how large the environment became, some cells always remained silent, perhaps as a reserve for other environments yet to be visited. Science , this issue p. 814