SummarySurvival demands that safe and unsafe contexts are met with different locomotor profiles, yet whether striatal microcircuitry links contextual valence to spontaneous locomotor vigor is unresolved. Here we test for striosome contributions to spontaneous locomotion using ablation, calcium imaging and chemogenetics in the context of a modified Light/Dark box test. We found that locomotor speed reflects the unlearned, external valence differential present in this test, and that striosomes gate valence-oriented speed selection. Our data suggest that striosomes dampen motor vigor associated with lesser valence, or elevated anxiety.HighlightsMice explore the light and dark zones in Light/Dark box with different walk speedStriosome ablation reduces restful slowing and elevates speed relative to zoneMany striosome neurons exhibit light-zone preference and speed related activityStriosome enhancement slows mice and blunts zone discrimination by speed
