Paradoxical accentuation of motivation following accumbens-pallidum disconnection.

The nucleus accumbens (NAc) and ventral pallidum (VP) are reciprocally connected, and activity within this circuit is thought to promote reward learning. Inconsistent with this notion, we find that disconnecting NAc medial shell and VP greatly enhances the attribution of value to a cue that is paired with reward. This result suggests that medial NAc shell and VP are both needed for attributing value to cues yet can also oppose one-another's functional contribution.