Tsukuba, Japan—Sleep deprivation typically results in longer and deeper sleep, thereby maintaining overall sleep quantity and quality through homeostatic regulation. However, the specific mechanisms by which the brain monitors and controls sleep homeostasis remain unclear.
To address this, the researchers focused on synaptic connections between neurons. They developed a novel molecular tool, SYNCit-K, which enhances synaptic strength, and EIN (excitatory-inhibitory neuronal network) model, a mathematical framework predicting the relationship between synaptic strength and brain activity. Application of SYNCit-K to the frontal cortex of mice induced sleep, while inhibition of synaptic enhancement prevented the induction of deep sleep. Enhanced synaptic strength in the prefrontal cortex returned to normal levels following subsequent sleep. These findings aligned with predictions from the EIN model, elucidating how increased synaptic connections in the brain induce sleep.
Understanding the role of synaptic strength in sleep homeostasis offers potential for developing new therapeutic approaches to improve sleep quantity and quality. Moreover, expanding the application of SYNCit-K and the EIN model could advance the understanding of brain functions and the computational theories underlying sleep.
###
This research was conducted as part of the World Premier International Research Center Initiative (WPI), JSPS KAKENHI grants, JST Strategic Basic Research Programs (CREST, ACT-X), JST-Mirai Program, AMED Moonshot Research and Development Program, AMED Brain/MINDS, and other research projects.
Original Paper
Title of original paper:
Prefrontal synaptic regulation of homeostatic sleep pressure revealed via synaptic chemogenetics
Journal:
Science
Correspondence
Assistant Professor SHI, Shoi
International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba
Project Professor KASAI, Haruo
International Research Center for Neurointelligence (WPI-IRCN), UTIAS, The University of Tokyo
Team Leader TOYOIZUMI, Taro
RIKEN Center for Brain Science
Related Link
International Institute for Integrative Sleep Medicine (WPI-IIIS)
About the World Premier International Research Center Initiative (WPI)
The WPI program was launched in 2007 by Japan's Ministry of Education, Culture, Sports, Science and Technology (MEXT) to foster globally visible research centers boasting the highest standards and outstanding research environments. Numbering more than a dozen and operating at institutions throughout the country, these centers are given a high degree of autonomy, allowing them to engage in innovative modes of management and research. The program is administered by the Japan Society for the Promotion of Science (JSPS).
See the latest research news from the centers at the WPI News Portal: https://www.eurekalert.org/newsportal/WPI
Main WPI program site: www.jsps.go.jp/english/e-toplevel
About International Institute for Integrative Sleep Medicine (IIIS), University of Tsukuba
World-class institute for sleep medicine, aiming to solve the mechanism of sleep/wakefulness by conducting basic to translational research
The mission of IIIS is to be a multidisciplinary, international hub for the research to elucidate the function of sleep and the fundamental mechanisms of sleep/wake regulation, to elucidate molecular pathogenesis of sleep disorders and related diseases, to develop preventive measures, diagnostic methods, and treatments for sleep.