Toward an Anatomy of Disappointment: Reward-Related Signals from the Globus Pallidus

The globus pallidus (internal segment, GPi) is traditionally regarded as part of the motor system. In this issue of Neuron, Hong and Hikosaka report on a little known projection from the monkey GPi to the lateral habenula that is modulated by reward. This adds an important branch to the brain's reward circuitry.