睡眠と生体リズムの最新の知見

Slow wave activity （SWA：＜４Hz） in electroencephalograms （EEG） appears during non-REM sleep, which is regulated homeostatically, increasing after wakefulness and returning to baseline during sleep. Recently, it has been suggested that SWA homeostasis may reflect synaptic changes underlying a cellular need for sleep. Huber et al. （Nature，４３０ （６９９５） ：７８‐８１，２００４） have shown that SWA homeostasis has a local component, which can be triggered by a learning task involving specific brain regions. We also found an impaired SWA rebound after sleep deprivation in fmr１ （fragile-X syndrome mental retardation１） knockout mice, indicating an involvement of fmr１gene in neural plasticity.
Clock genes regulating circadian rhythm are recently thought to modulate several brain functions. Spanagel et al. （Nature Medicine，１１ （１） ：３５‐４２，２００４） have shown that per２mutant mice show alterations in the glutamatergic system in the brain, accompanied by increasing alcohol intake. They also found that, in humans, genetic variations of human per ２ are related to the alcohol consumption Furthermore, clock genes have been indicated to have important roles in not only brain but also peripheral organs.
In future, we need an animal model for“insomnia”which is one of the most common sleep disorders in humans.

四国医学雑誌 : http://www.tokushima-u.ac.jp/med/research/shikoku_acta_medica.html