Keith Hengen

Assistant Professor of Biology
Washington University

Circuit-specific flickering of sleep & wake predicts natural behaviors: the minimal unit of brain sleep

Sleep and wake are understood to be slow, long-lasting processes that span the entire brain. The possibility that local circuits throughout the brain might routinely and independently switch between sleep and wake has been difficult to address due to reliance on surface measurements of brain rhythms to classify state.

By recording high resolution neural activity across diverse regions of the murine brain for 24 h, we learn reliable rules of sleep/wake embedding in each circuit at the scale of 100 microseconds and 100 microns, a 7 order of magnitude improvement in resolution over standard approaches.

We show that diverse microcircuits regularly switch between sleep-like and wake-like states (flickers), independent of the rest of the brain and the arousal state of the animal. Furthermore, high sleep pressure suppresses wake flickers within sleep, but does not modulate sleep flickers during wake. In contrast, sleep flickers during complex, natural behavior results in a momentary pause of movement.

Our results reveal that sleep and wake arise from an unstable patchwork of states throughout the brain.

THURSDAY  I  DEC. 8 I  3:30-4:30 PM CST  I  HYBRID SEMINAR