The diversity and specificity of functional connectivity across spatial and temporal scales

•Nearby neurons exhibit diverse patterns of local and long-range functional connectivity, that depend on cell type and change with behavioral state.•Neural activity is coordinated within and across areas on timescales from milliseconds to minutes and hours.•Perturbing neuronal activity with high specificity and precision permits control over the diverse pathways facilitating global brain states. Macroscopic neuroimaging modalities in humans have revealed the organization of brain-wide activity into distributed functional networks that re-organize according to behavioral demands. However, the inherent coarse-graining of macroscopic measurements conceals the diversity and specificity in responses and connectivity of many individual neurons contained in each local region. New invasive approaches in animals enable recording and manipulating neural activity at meso- and microscale resolution, with cell-type specificity and temporal precision down to milliseconds. Determining how brain-wide activity patterns emerge from interactions across spatial and temporal scales will allow us to identify the key circuit mechanisms contributing to global brain states and how the dynamic activity of these states enables adaptive behavior.