Experience-Dependent Hemispheric Dominance During Motor Planning

Abstract

Understanding the neural mechanism underlying lateralized brain functions is a fundamental question in neuroscience. Classical studies identified lateralized cortical areas and the underlying neural correlates for various cognitive functions. Despite extensive study, it remains unclear whether and how the correlated activity causally supports lateralized brain functions. We here address these questions in the anterior lateral motor cortex (ALM) of mice performing a tactile-based task with a motor planning component. Inhibiting the dominant ALM (left/right, depending on the sensory-motor experience) produced much larger behavioral deficits than the non-dominant ALM despite neurons in both ALMs showed a similar pattern of activity. Sensory information reached the left ALM and was converted to motor planning activity in the dominant ALM (left/right). Inhibiting the dominant ALM disrupted motor planning activity in the non-dominant ALM, but not vice versa. Together, these results reveal motor planning activity in the dominant ALM alone supports lateralized cognitive function.