Whisking asymmetry signals motor preparation and the behavioral state of mice
Sina E Dominiak, Mostafa A Nashaat, Keisuke Sehara, Hatem Oraby, Matthew E Larkum, and Robert NS Sachdev
A central function of the brain is to plan, predict, and imagine the effect of movement in a dynamically changing environment. Here weshow that in mice head-fixed in a plus-maze, floating on air, and trained to pick lanes based on visual stimuli, the asymmetric movement,and position of whiskers on the two sides of the face signals whether the animal is moving, turning, expecting reward, or licking. We showthat (1) whisking asymmetry is coordinated with behavioral state, and that behavioral state can be decoded and predicted based onasymmetry, (2) even in the absence of tactile input, whisker positioning and asymmetry nevertheless relate to behavioral state, and (3)movement of the nose correlates with asymmetry, indicating that facial expression of the mouse is itself correlated with behavioral state.These results indicate that the movement of whiskers, a behavior that is not instructed or necessary in the task, can inform an observerabout what a mouse is doing in the maze. Thus, the position of these mobile tactile sensors reflects a behavioral and movement-preparation state of the mouse.