抄録
There are two entrainment stimuli of circadian rhythm, restricted feeding and light. Light-induced expression of mPer1 and mPer2 in the suprachiasmatic nucleus (SCN) closely correlated with the light-induced entrainment of locomotor activity rhythm. Previously, we investigated the effects of restricted feeding (RF) on the expression of mPer1 and mPer2 mRNA in the paraventricular nucleus (PVN), pyriformcortex, hippocampus and cerebral cortex of mice. To understand the relation between clock genes and RGS16, we investigated mRNA of RGS16 in restricted feeding.
In situ hybridization revealed the circadian expression of RGS16 mRNA. The expression of the RGS16 mRNA showed a clear peak in SCN at daytime, as well as mPer1 and mPer2. Contrary, a peak in PVN (paraventricular nucleus), pyriformcortex, cerebral cortex and hippocampus has seen at nighttime. After 6 days of scheduled-RF (4 hours in the daytime) RGS16 mRNA level showed a peak in the cerebral cortex, hippocampus, PVN and pyriform cortex in the daytime. Scheduled-RF attenuated these rhythmicity outside SCN. However, the expression pattern of RGS16 mRNA in SCN didn't show the phase shift on scheduled-RF.
These results show the relation between clock genes and G-protein signaling related gene for food stimuli outside SCN regions. [Jpn J Physiol 54 Suppl:S210 (2004)]
