Cover legend: Models of organization of the globus pallidus (GP). The pale transparent globes represent the GP, the descending blue columns represent the input from the striatum, the cubes symbolize neurons, and the cones symbolize their outputs. The top right model illustrates the organization of the GP as a relay nucleus. The model in the foreground symbolizes the organization as suggested by the findings described by Sadek et al. The yellow cubes represent "outer GP neurons", and the red cubes represent the "inner GP neurons". The differing influences of striatal input and intrinsic connectivity give rise to the different multicolored outputs of the two populations of GP neurons. For more information, see the article by Sadek et al. in this issue (pages 6352–6362).