Sleep phenotyping in a mouse model of extreme trait anxiety.
BACKGROUND
There is accumulating evidence that anxiety impairs sleep. However, due to high sleep variability in anxiety disorders, it has been difficult to state particular changes in sleep parameters caused by anxiety. Sleep profiling in an animal model with extremely high vs. low levels of trait anxiety might serve to further define sleep patterns associated with this psychopathology.


RESULTS
Sleep-wake behavior in mouse lines with high (HAB), low (LAB) and normal (NAB) anxiety-related behaviors was monitored for 24 h during baseline and recovery after 6 h sleep deprivation (SD). The amounts of each vigilance state, sleep architecture, and EEG spectral variations were compared between the mouse lines. In comparison to NAB mice, HAB mice slept more and exhibited consistently increased delta power during non-rapid eye movement (NREM) sleep. Their sleep patterns were characterized by heavy fragmentation, reduced maintenance of wakefulness, and frequent intrusions of rapid eye movement (REM) sleep. In contrast, LAB mice showed a robust sleep-wake rhythm with remarkably prolonged sleep latency and a long, persistent period of wakefulness. In addition, the accumulation of delta power after SD was impaired in the LAB line, as compared to HAB mice.


CONCLUSIONS
Sleep-wake patterns were significantly different between HAB and LAB mice, indicating that the genetic predisposition to extremes in trait anxiety leaves a biological scar on sleep quality. The enhanced sleep demand observed in HAB mice, with a strong drive toward REM sleep, may resemble a unique phenotype reflecting not only elevated anxiety but also a depression-like attribute.
Max Planck Institute of Psychiatry, Munich, Germany.
Vladimira
V
Jakubcakova
Cornelia
C
Flachskamm
Rainer
R
Landgraf
Mayumi
M
Kimura
D000818:Animals; D001008:Anxiety Disorders / Q000503:physiopathology*; D004195:Disease Models, Animal; D004569:Electroencephalography; D006706:Homeostasis; D007837:Latency Period, Psychological; D008297:Male; D051379:Mice; D010641:Phenotype; D019655:Quantitative Trait, Heritable; D012890:Sleep / Q000502:physiology*; D012892:Sleep Deprivation / Q000503:physiopathology; D012895:Sleep, REM / Q000502:physiology; D014851:Wakefulness / Q000502:physiology