The mouse motor system contains multiple premotor areas and partially follows human organizational principles
Alberto Lazari, Mohamed Tachrount, Juan Miguel Valverde, Daniel S. Papp, Antoine Beauchamp, Paul J. McCarthy, Jacob Ellegood, Joanes Grandjean, Heidi Johansen‐Berg, Valerio Zerbi, Jason P. Lerch, Rogier B. Mars
Abstract
While humans are known to have several premotor cortical areas, secondary motor cortex (M2) is often considered to be the only higher-order motor area of the mouse brain and is thought to combine properties of various human premotor cortices. Here, we show that axonal tracer, functional connectivity, myelin mapping, gene expression, and optogenetics data contradict this notion. Our analyses reveal three premotor areas in the mouse, anterior-lateral motor cortex (ALM), anterior-lateral M2 (aM2), and posterior-medial M2 (pM2), with distinct structural, functional, and behavioral properties. By using the same techniques across mice and humans, we show that ALM has strikingly similar functional and microstructural properties to human anterior ventral premotor areas and that aM2 and pM2 amalgamate properties of human pre-SMA and cingulate cortex. These results provide evidence for the existence of multiple premotor areas in the mouse and chart a comparative map between the motor systems of humans and mice.