Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2006: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2005: ¥2,200,000 (Direct Cost: ¥2,200,000)
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Research Abstract |
Prostaglandin (PG) D_2 and adenosine are potent humoral sleep-inducing factors that accumulate in the brain during prolonged wakefulness. Adenosine/A_<2A> receptor system plays a pivotal role in the sleep induced by PGD_2. Microarray analysis of expressed genes in the rat brain during sleep induced by intracerebroventricular infusion of PGD_2 or A_<2A> agonist CGS21680 revealed that expression levels of glial cell genes, such as glial fibrillary acidic protein (GFAP), heat shock protein 27 (HSP27), and metallothionein-1 (MT-1), were upregulated. To examine the expression of genes in glial cells, including that of hematopoietic PGD synthase (H-PGDS) and Iba-1 in microglia, and lipocalin-type PGDS (L-PGDS) and pi-GST in oligodendrocytes, we analyzed their levels of mRNA and proteins in the cortex, corpus callosum, hippocampus, thalamus, and hypothalamus of the mouse brain after 6 h of sleep deprivation. Sleep deprivation caused a decrease in mRNA expression of H-PGDS in all the five understudied regions of mouse brain, but not that of GFAP, HSP27, and MT-1. Likewise, expression of Iba-1 mRNA in the thalamus and hypothalamus and pi-GST in the cortex, corpus callosum, and hypothalamus also decreased. Immunoreactivity of H-PGDS and Iba-1 decreased in the microglia of each concerned region. In situ hybridization and immunohistochemical analyses revealed an increase of L-PGDS in oligodendrocytes. These results indicate that gene expression in glial cells deviates during sleep deprivation.
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