Setting the biological time in central and peripheral clocks during ontogenesis.
In mammals, the principal circadian clock within the suprachiasmatic nucleus (SCN) entrains the phase of clocks in numerous peripheral tissues and controls the rhythmicity in various body functions. During ontogenesis, the molecular mechanism responsible for generating circadian rhythmicity develops gradually from the prenatal to the postnatal period. In the beginning, the maternal signals set the phase of the newly developing fetal and early postnatal clocks, whereas the external light-dark cycle starts to entrain the clocks only later. This minireview discusses the complexity of signaling pathways from mothers and the outside world to the fetal and newborn animals' circadian clocks.
Department of Neurohumoral Regulations, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague 4, Czech Republic. sumova@biomed.cas.cz
Alena
A
Sumová
Zdenka
Z
Bendová
Martin
M
Sládek
Rehab
R
El-Hennamy
Kristýna
K
Laurinová
Zuzana
Z
Jindráková
Helena
H
Illnerová
D000818:Animals; D001683:Biological Clocks; D003624:Darkness; D008027:Light; D013493:Suprachiasmatic Nucleus / Q000502:physiology*