Grid cells that rats use for navigation remain active even during sleep, studies show
The brain’s mapmakers don’t get a break, even for sleep. Grid cells, specialized nerve cells that help keep people and other animals oriented, stay on the clock 24/7, two preliminary studies on rats suggest. Results from the studies, both posted October 5 at bioRxiv.org, highlight the stability of the brain’s ‘inner GPS’ system.
Nestled in a part of the brain called the medial entorhinal cortex, grid cells fire off regularly spaced signals as a rat moves through the world, marking a rat’s various locations. Individual grid cells work together to create a mental map of the environment. But scientists didn’t know what happens to this map when an animal no longer needs it, such as during sleep.
Grid cells, it turns out, maintain their mapmaking relationships even in sleeping rats, report two