Sleep properties of CS mice with spontaneous rhythm splitting in constant darkness

Shizufumi Ebihara, Satoru Miyazaki, Hirotake Sakamaki, Takashi Yoshimura

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)


In mice, genetic differences between inbred strains have been shown for several parameters of sleep and circadian activity rhythms. Our previous studies have demonstrated that CS mice have three remarkable characteristics in the circadian rhythm of locomotor activity: (1) high activity both during the day and night, (2) unstable freerunning period and (3) spontaneous rhythm splitting. In order to characterize sleep properties of CS mice, we compared circadian sleep patterns of CS with those of C57BL/6J and C3H/He mice which have normal circadian activity rhythms. Although C57BL/6J and C3H/He mice exhibited clear daily sleep-wake rhythms in the amount of each sleep parameter (Awake, SWS, PS), CS mice did not show clear rhythms in these parameters. The differences were particularly conspicuous in PS; no apparent day-night differences in the amount of PS, PS counts and PS interval (the interval between successive PS episodes) in CS mice. In addition, the ratio of PS to total sleep time was significantly larger in CS mice than other strains. Of these parameters, the most considerable was PS latency which was extremely short and direct transition from Awake to PS without appearance of SWS frequently occurred in these mice. These results indicate that CS mice may be useful for the understanding of sleep mechanisms and its dysfunction.

Original languageEnglish
Pages (from-to)121-127
Number of pages7
JournalBrain Research
Issue number1
Publication statusPublished - Aug 1 2003
Externally publishedYes


  • Circadian rhythm
  • CS mouse
  • Rhythm splitting
  • Sleep

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology


Dive into the research topics of 'Sleep properties of CS mice with spontaneous rhythm splitting in constant darkness'. Together they form a unique fingerprint.

Cite this