Back to Search Start Over

Lesions of suprachiasmatic nucleus modify sleep structure but do not alter the total amount of daily sleep in rats

Authors :
Wei-Min Qu
Xin-Hong Xu
Xu-Guang Liu
Zhi-Li Huang
Bin-Jia Zhang
Source :
Sleep and Biological Rhythms. 10:293-301
Publication Year :
2012
Publisher :
Springer Science and Business Media LLC, 2012.

Abstract

The suprachiasmatic nucleus (SCN) is a master circadian pacemaker. It regulates the 24 h timing of many physiological processes, including sleeping and waking. After bilateral SCN lesions, the circadian rhythm of the sleep wake cycle was completely eliminated, but the characteristics of the sleep wake profile were not well clarified. In the present study, bilateral suprachiasmatic nucleus lesions (SCNX) were created in rats to determine the effects of SCNX on the sleep-wake profile in terms of number of episodes, mean duration of each stage and number of transitions between stages. Although bilateral SCN lesions completely eliminated the circadian rhythm in the sleepwake cycle, there was no significant change in the total amount of daily sleep or wakefulness before and after lesions. However, the SCN-lesioned rats exhibited anincreased episode number of wake and non-rapid eye movement (NREM) sleep during dark period and a decreased one during light period. The mean duration of wakefulness decreased significantly during the dark period and increased during the light period. The number of transitions between NREM sleep and wakefulness increased during the dark period and decreased during the light period. The NREM sleep power density and total number of episodes, number of transitions, and mean duration were not significantly different from those of sham controls when viewed over 24 h. These results indicate that lesions of suprachiasmatic nucleus did not alter the total amount of daily sleep but did modify the structure of sleepwake profiles in rats.

Details

ISSN :
14469235
Volume :
10
Database :
OpenAIRE
Journal :
Sleep and Biological Rhythms
Accession number :
edsair.doi...........8336fb63126ab6a0a74e498208c378f3