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Updated: Aug 31, 2025

Optogenetic Manipulation of Neural Circuits During Monitoring Sleep/wakefulness States in Mice
Published on: June 19, 2019
A cognitive process occurring during sleep is revealed by rapid eye movements
Yuta Senzai1,2, Massimo Scanziani1,2
1Department of Physiology, University of California, San Francisco, San Francisco, CA, USA.
Abstract:
Since the discovery of rapid eye movement (REM) sleep, the nature of the eye movements that characterize this sleep phase has remained elusive. Do they reveal gaze shifts in the virtual environment of dreams or simply reflect random brainstem activity? We harnessed the head direction (HD) system of the mouse thalamus, a neuronal population whose activity reports, in awake mice, their actual HD as they explore their environment and, in sleeping mice, their virtual HD. We discovered that the direction and amplitude of rapid eye movements during REM sleep reveal the direction and amplitude of the ongoing changes in virtual HD. Thus, rapid eye movements disclose gaze shifts in the virtual world of REM sleep, thereby providing a window into the cognitive processes of the sleeping brain.
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