抄録
Prostaglandins (PGs) are thought to regulate brain functions. We have reported that prostaglandins including PGD2, PGE2, and PGF2α are produced by COX-2 expression in neurons in the cerebral cortex following cortical spreading depression, the propagation of neuronal membrane depolarization throughout the cortical hemisphere, in rats. In such a model for neuronal excitation in the cortex, the amount of non-REM sleep, but not of REM sleep, increased subsequently for several hours in the animals, and the increase was completely attenuated by application of NS-398, a COX-2 inhibitor. In the same model, furthermore, perineuronal satellite cells which exist ubiquitously all over the cortex and were recently identified as cortical progenitor cells, started to proliferate in the hemisphere and differentiated into oligodendrocytes, astrocytes, and immature neurons in weeks. The proliferation activity depended on numbers of induced spreading depression, and was also attenuated by NS-398. The number of cells involved in the cell cycle increased in the cortical slices by application of prostaglandins including PGF2α. These observations indicate that prostaglandins regulate cell renewal in the cortical tissue. Prostaglandins are thought to be key molecules which relieve excessive brain activity by inducing non-REM sleep and bring about brain tissue remodeling for building up tolerance to the excessive activity. [J Physiol Sci. 2007;57 Suppl:S49]
