Invariant inhibition to calculate prediction errors?

The ventral tegmental area (VTA) has a pivotal role in motivated behavior. Much of the research on the VTA has focused on the mesocorticolimbic dopamine projections and their role in the computation of a ‘reward prediction error’ (RPE) for reward-guided learning. In a recent study, Zhou et al. report that VTA GABA neurons, the axons of which innervate the ventral pallidum (VP), have a unique role in signaling reward value to the basal ganglia and guiding reward seeking.