Abstract
The central circadian pacemaker, the suprachiasmatic nucleus (SCN), encodes day length information by mechanisms that are not well understood. Here, we report that genetic ablation of miR-132/212 alters entrainment to different day lengths and non-24 hr day-night cycles, as well as photoperiodic regulation of Period2 expression in the SCN. SCN neurons from miR-132/212-deficient mice have significantly reduced dendritic spine density, along with altered methyl CpG-binding protein (MeCP2) rhythms. In Syrian hamsters, a model seasonal rodent, day length regulates spine density on SCN neurons in a melatonin-independent manner, as well as expression of miR-132, miR-212, and their direct target, MeCP2. Genetic disruption of Mecp2 fully restores the level of dendritic spines of miR-132/212-deficient SCN neurons. Our results reveal that, by regulating the dendritic structure of SCN neurons through a MeCP2-dependent mechanism, miR-132/212 affects the capacity of the SCN to encode seasonal time.
Original language | English (US) |
---|---|
Pages (from-to) | 505-520 |
Number of pages | 16 |
Journal | Cell reports |
Volume | 19 |
Issue number | 3 |
DOIs | |
State | Published - Apr 18 2017 |
Keywords
- MeCP2
- circadian rhythms
- dendritic morphology
- entrainment
- miR-132/212
- microRNA
- seasonal timekeeping
- spinogenesis
- structural plasticity
- suprachiasmatic nucleus
ASJC Scopus subject areas
- General Biochemistry, Genetics and Molecular Biology