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Region-Specific Dissociation between Cortical Noradrenaline Levels and the Sleep/ Wake Cycle
- Publication Year :
- 2016
-
Abstract
- The activity of the noradrenergic system of the locus coeruleus (LC) is high in wake and low in sleep. LC promotes arousal and EEG activation, as well as attention, working memory, and cognitive flexibility. These functions rely on prefrontal cortex and are impaired by sleep deprivation, but the extent to which LC activity changes during wake remains unclear. Moreover, it is unknown whether noradrenergic neurons can sustain elevated firing during extended wake. Recent studies show that relative to LC neurons targeting primary motor cortex (M1), those projecting to medial prefrontal cortex (mPFC) have higher spontaneous firing rates and are more excitable. These results suggest that noradrenaline (NA) levels should be higher in mPFC than M1, and that during prolonged wake LC cells targeting mPFC may fatigue more, but direct evidence is lacking.We performed in vivo microdialysis experiments in adult (9-10 weeks old) C57BL/6 mice implanted for chronic electroencephalographic recordings. Cortical NA levels were measured during spontaneous sleep and wake (n = 8 mice), and in the course of sleep deprivation (n = 6).We found that absolute NA levels are higher in mPFC than in M1. Moreover, in both areas they decline during sleep and increase during wake, but these changes are faster in M1 than mPFC. Finally, by the end of sleep deprivation NA levels decline only in mPFC.Locus coeruleus (LC) neurons targeting prefrontal cortex may fatigue more markedly, or earlier, than other LC cells, suggesting one of the mechanisms underlying the cognitive impairment and the increased sleep presure associated with sleep deprivation.A commentary on this article appears in this issue on page 11.
- Subjects :
- 0301 basic medicine
Microdialysis
Sleep, REM
Prefrontal Cortex
Mice
Norepinephrine
03 medical and health sciences
0302 clinical medicine
Basic Science
Physiology (medical)
medicine
Humans
Animals
Effects of sleep deprivation on cognitive performance
Wakefulness
Prefrontal cortex
Neuroscience of sleep
Fatigue
Neurons
Electroencephalography
Mice, Inbred C57BL
Sleep deprivation
030104 developmental biology
nervous system
Commentary
Sleep Deprivation
Locus coeruleus
Locus Coeruleus
Neurology (clinical)
medicine.symptom
Sleep onset
Primary motor cortex
Cognition Disorders
Sleep
Psychology
Neuroscience
psychological phenomena and processes
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Accession number :
- edsair.doi.dedup.....61721cc7a41f755b7f5117c3ebbb82dd