Changes in Per1 and Per2 expression during early postnatal stage in rat masseters

Numerous studies reported that the rhythmic expression of Period (Per) 1 and per2 are different depending on the tissues during postnatal ontogenesis. However, the changes of Per1 and Per2 expression in masticatory muscles remains unknown. The aim of the study was to explore the changes in Per1 and Per2 expression during early postnatal stage in rat masseters. Rat masseters were isolated in the light and dark frompostnatalday 1 (P1) to P21, then...