Hubbard J, Ruppert E, Calvel L, Robin-Choteau L, Gropp CM, Allemann C, Reibel S, Sage-Ciocca D, Bourgin P. Arvicanthis ansorgei, a Novel Model for the Study of Sleep and Waking in Diurnal Rodents.
Sleep 2015;
38:979-88. [PMID:
25409107 DOI:
10.5665/sleep.4754]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 07/18/2014] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES
Sleep neurobiology studies use nocturnal species, mainly rats and mice. However, because their daily sleep/wake organization is inverted as compared to humans, a diurnal model for sleep studies is needed. To fill this gap, we phenotyped sleep and waking in Arvicanthis ansorgei, a diurnal rodent widely used for the study of circadian rhythms.
DESIGN
Video-electroencephalogram (EEG), electromyogram (EMG), and electrooculogram (EOG) recordings.
SETTING
Rodent sleep laboratory.
PARTICIPANTS
Fourteen male Arvicanthis ansorgei, aged 3 mo.
INTERVENTIONS
12 h light (L):12 h dark (D) baseline condition, 24-h constant darkness, 6-h sleep deprivation.
MEASUREMENTS AND RESULTS
Wake and rapid eye movement (REM) sleep showed similar electrophysiological characteristics as nocturnal rodents. On average, animals spent 12.9 h ± 0.4 awake per 24-h cycle, of which 6.88 h ± 0.3 was during the light period. NREM sleep accounted for 9.63 h ± 0.4, which of 5.13 h ± 0.2 during dark period, and REM sleep for 89.9 min ± 6.7, which of 52.8 min ± 4.4 during dark period. The time-course of sleep and waking across the 12 h light:12 h dark was overall inverted to that observed in rats or mice, though with larger amounts of crepuscular activity at light and dark transitions. A dominant crepuscular regulation of sleep and waking persisted under constant darkness, showing the lack of a strong circadian drive in the absence of clock reinforcement by external cues, such as a running wheel. Conservation of the homeostatic regulation was confirmed with the observation of higher delta power following sustained waking periods and a 6-h sleep deprivation, with subsequent decrease during recovery sleep.
CONCLUSIONS
Arvicanthis ansorgei is a valid diurnal rodent model for studying the regulatory mechanisms of sleep and so represents a valuable tool for further understanding the nocturnality/diurnality switch.
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