Effects of sleep deprivation and rebound sleep on the proliferation of the neural stem cells in adult rats

Abstract

The neural stem cells (NSCs) possess the self-renewal and multipotential abilities and are located not only in the development mammalian brain but also in the adult brain, especially abundant in the anteior subventricular zone (aSVZ) and subgranular zone (SGZ) of hippocampal dentate gyrus. In the present study, we examined the effects of sleep deprivation and rebound sleep after sleep deprivation on the proliferation and the differentiation of the NSCs in aSVZ and SGZ of adult rats. Male SD rats were deprived of total sleep for 96 hr by treadmill method and some rats were thereafter returned to their home cages. Rats were injected with BrdU (200 mg/kg i.p.) at the midpoint (48 hr after) or the endpoint (96 hr after) of treadmill and their brain were removed 48 hr or 6 hr after, respectively. The number of BrdU-incorporated cells in the aSVZ and the SGZ were quantified by BrdU-immunohistochemistry. We found that sleep deprivation failed to affect the number of BrdU-positive cells in the aSVZ and SGZ. However, rebound sleep after sleep deprivation increased the number of BrdU-positive cells in the SGZ, but not in the aSVZ. These results suggest that sleep changes the proliferative activity of the NSCs in the SGZ of the dentate gyrus. [Jpn J Physiol 55 Suppl:S180 (2005)]