Caffeine lengthens circadian rhythms in mice

Publication year: 2011
Source: Biochemical and Biophysical Research Communications, In Press, Accepted Manuscript, Available online 13 June 2011

Hideaki, Oike , Masuko, Kobori , Takahiro, Suzuki , Norio, Ishida

Although caffeine alters sleep in many animals, whether or not it affects mammalian circadian clocks remains unknown. Here, we found that incubating cultured mammalian cell lines, human osteosarcoma U2OS cells and mouse fibroblast NIH3T3 cells, with caffeine lengthened the period of circadian rhythms. Adding caffeine to ex vivo cultures also lengthened the circadian period in mouse liver explants from Per2::Luciferase reporter gene knockin mice, and caused a phase delay in brain slices containing the suprachiasmatic nucleus (SCN), where the central circadian clock in mammals is located. Furthermore, chronic caffeine consumption ad libitum for a week delayed the phase of the…

 Highlights: ► Caffeine lengthened the circadian period in mammalian cell lines. ► Caffeine lengthened the circadian period in mouse liver explants. ► Caffeine delayed the circadian phase in brain slices containing SCN. ► Chronic caffeine consumption delayed the phase of the mouse liver clock. ► Chronic caffeine consumption lengthened the circadian locomotor rhythm in mice.