title: Sleep as a biological problem: an overview of frontiers in sleep research.
abstract: Sleep is a physiological process not only for the rest of the body but also for several brain functions such as mood, memory, and consciousness. Nevertheless, the nature and functions of sleep remain largely unknown due to its extremely complicated nature and lack of optimized technology for the experiments. Here we review the recent progress in the biology of the mammalian sleep, which covers a wide range of research areas: the basic knowledge about sleep, the physiology of cerebral cortex in sleeping animals, the detailed morphological features of thalamocortical networks, the mechanisms underlying fluctuating activity of autonomic nervous systems during rapid eye movement sleep, the cutting-edge technology of tissue clearing for visualization of the whole brain, the ketogenesis-mediated homeostatic regulation of sleep, and the forward genetic approach for identification of novel genes involved in sleep. We hope this multifaceted review will be helpful for researchers who are interested in the biology of sleep.
authors.affiliation: International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, 305-8575, Japan. kanda.takeshi.fu@u.tsukuba.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kanda
authors.affiliation: International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, 305-8575, Japan. tsujinatsu@gmail.com.
authors.forename: Natsuko
authors.initials: N
authors.lastname: Tsujino
authors.affiliation: Department of Oral Anatomy and Cell Biology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Kuramoto
authors.affiliation: Department of Science and Technology, Fukushima University, Fukushima, 960-1296, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Koyama
authors.affiliation: Department of Systems Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.|Laboratory for Synthetic Biology, RIKEN Quantitative Biology Center, Osaka, 565-0871, Japan.|AMED-CREST, AMED, Tokyo, 100-0004, Japan.
authors.forename: Etsuo A
authors.initials: EA
authors.lastname: Susaki
authors.affiliation: Department of Integrative Physiology, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, 770-8503, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Chikahisa
authors.affiliation: International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Ibaraki, 305-8575, Japan.|Department of Anatomy, Toho University School of Medicine, Tokyo, 143-8540, Japan.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Funato
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology; D001921:Brain / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology; D006706:Homeostasis; D008322:Mammals / Q000502:physiology*; D012890:Sleep / Q000502:physiology*
keywords: Amygdala; Forward genetics; Ketogenesis; Sleep; Thalamus; Tissue clearing