Ventral tegmental dopamine neurons control the impulse vector during motivated behavior

The Ventral Tegmental Area (VTA) is a major source of dopamine, especially to the limbic brain regions. Despite decades of research, the function of VTA dopamine neurons remains controversial. Here, using a novel head-fixed behavioral system with five orthogonal force sensors, we show for the first time that distinct populations of VTA dopamine activity precisely represent the impulse vector (force exerted over time) generated by the animal. Optogenetic excitation of VTA dopamine neurons quantitatively determines impulse in the forward direction, and optogenetic inhibition produces impulse in the backward direction. At the same time, these neurons also regulate the initiation and execution of anticipatory licking. Our results indicate that VTA controls the magnitude, direction, and duration of force used to move towards or away from any motivationally relevant stimuli. One Sentence Summary VTA dopamine bidirectionally controls impulse vector and anticipatory behavior