Sparse long-range interneurons orchestrate cortical synchrony to propel sleep

A rare subset of somatostatin-expressing Sst-Chodl interneurons in the mouse neocortex has long-range intracortical projections and is preferentially active during low-arousal states; when selectively activated, these neurons drive widespread cortical synchronization and sleep, demonstrating that cortex actively regulates sleep alongside subcortical mechanisms.