In a study published in Nature Neuroscience, researchers from Dr. Liu Danqian’s Lab at the Institute of Neuroscience, Center for Excellence in Brain Science and Intelligence Technology of the Chinese Academy of Sciences demonstrated that selective retrosplenial cortex activation encodes and regulates rapid eye movement (REM) sleep, revealed the cortical activity patterns and a selectively activated cortical region during REM sleep—the retrosplenial cortex (RSC)—discovered and characterized two distinct substages of REM sleep, and confirmed that RSC neuronal activity encodes and regulates the two substage transition.