 In this study, researchers examined how movement-correlated brain activity is present across different species and brain regions. They used fast-hole brain-light field imaging in adult Drosophila to observe how spontaneous bouts of walking are related to global changes in neuronal activity. The researchers found that there was a tight correlation between spontaneous walks and global neuronal activity. Additionally, they identified specific neurons that responded differently depending on whether the animal was walking or turning. For instance, serotonin-producing neurons were inhibited when the animal was walking. Furthermore, the researchers found that both spontaneous and forced walks resulted in similar levels of activity in most brain regions. This suggests that movement-related sensory or proprioceptive information plays a large role in global brain activity. This article was authored by Sophie Amon, Karen Wai-Cheng, Julijana Gujiva, and others.