Zoological Society of Japan, Hokkaido Branch, 613th Branch Lecture
Date and Time: Tuesday, August 4, 2026, 17:00–18:00
Location: Hokkaido University, Faculty of Science, Building No. 5, 8th Floor, Room 813
Speaker: Dr. Shuzo Sakata (University of Strathclyde)
Title: Whole-Brain Distributed Sleep Codes in Health and Disease
Abstract: Sleep architecture is shaped by neuronal populations operating across various time scales, yet the underlying mechanisms remain largely enigmatic. We recently measured neural activity across more than 40 brain regions in mice to elucidate brain-wide sleep mechanisms, and we would like to introduce these findings. First, on a slow time scale ranging from minutes to seconds, brain-wide activity patterns were reorganized in accordance with changes in arousal level, allowing the sleep state to be read out from any brain region. Notably, REM sleep emerged as a state in which the entire brain is activated. Furthermore, state transitions followed simple, low-dimensional trajectories: during the transition from wakefulness to non-REM sleep, cortical and subcortical neuronal populations exhibited opposing movements, whereas during the transition to REM sleep, they changed synchronously. On the other hand, on a fast time scale ranging from seconds to milliseconds, slow brain waves during non-REM sleep (slow waves and delta waves) established a global rhythm, which nested diverse fast brain waves to functionally integrate activity across regions. During REM sleep, the coupling of theta waves and P-waves synchronized neural firing across regions. Moreover, the accessibility of neuromodulators to various parts of the brain served as a clue to predict activity changes corresponding to sleep states, and it was also found that extremely slow neural dynamics reflecting past sleep history control the cycle of non-REM and REM sleep. This study provides a comprehensive picture, captured at cellular resolution, of how brain-wide neuronal populations coordinate and operate during sleep. Additionally, in this seminar, we would like to present research findings from applying our recently developed multi-site photometry technology to Alzheimer's disease model mice during sleep and wakefulness.
Caretaker:
Tomomi Tsunematsu (Faculty of Science, Hokkaido University)
tsune[a]sci.hokudai.ac.jp
Please change [a] to @.
Ezo squirrel (Provided by Minorukaz Nagahara, Asahikawa Medical University RI Research Facility)
