ISSN 2630-0583 (Print)
ISSN 2630-0656 (Online)
Journal of Current Science and Technology
Rangsit Journal of Arts and Sciences. Vol.7 No.1 , January - June 2017.
Sleep phenotype of Period3 gene knockout mice under light-dark entrained condition
Circadian rhythmicity contributes to sleep-wake phenotypes, and is regulated by clock genes. Although Period3 gene (Per3) is not essential for circadian rhythm generation, it does modulate circadian clock outputs and polymorphisms of this gene related to some circadian sleep disorders. We studied the role of Per3 gene on sleep-wake phenotypes by comparing Per3 knockout mice (Per3-/-) with wild-type (WT) mice under light-dark condition. Here we report that Per3-/- mice had more wakefulness and less non-rapid eye movement sleep (NREMS) at ZT 0 in the light period than WT mice. Likewise, in last hour of the light period on second day, wakefulness was higher and NREMS was lower in Per3 mutants. Per3-/- mice began their main sleeping episodes later and waking episodes earlier than WT mice, whereas the average time spent in wakefulness, NREM and rapid eye movement (REM) sleep were not different between the genotypes. In addition, Per3-/- mice had significantly less sleep bouts than WT mice at early and late light periods. These results demonstrate the influence of Per3 on sleep phenotypes related to light-dark transition and additionally show subtle effects on sleep times and sleep fragmentation.