Region-Specific Dissociation between Cortical Noradrenaline Levels and the Sleep/Wake Cycle

• DOI: 10.5665/sleep.5336
• Publication Date: 2015-12-31T11:00:47Z
• Authors: Michele Bellesi; Giulio Tononi; Chiara Cirelli; Pier Andrea Serra
• Keywords: Locus coeruleus; Microdialysis; Sleep restriction; Neuroscience of sleep; Sleep

The activity of the noradrenergic system locus coeruleus (LC) is high in wake and low sleep. LC promotes arousal EEG activation, as well attention, working memory, cognitive flexibility. These functions rely on prefrontal cortex are impaired by sleep deprivation, but extent to which changes during remains unclear. Moreover, it unknown whether neurons can sustain elevated firing extended wake. Recent studies show that relative targeting primary motor (M1), those projecting medial (mPFC) have higher spontaneous rates more excitable. results suggest noradrenaline (NA) levels should be mPFC than M1, prolonged cells may fatigue more, direct evidence lacking. We performed vivo microdialysis experiments adult (9–10 weeks old) C57BL/6 mice implanted for chronic electroencephalographic recordings. Cortical NA were measured (n = 8 mice), course deprivation 6). found absolute M1. both areas they decline increase wake, these faster M1 mPFC. Finally, end only Locus markedly, or earlier, other cells, suggesting one mechanisms underlying impairment increased presure associated with deprivation. A commentary this article appears issue page 11. For first time we two mouse cortical across physiological sleep/wake cycle response findings at least some coeruleus, best characterized wake-promoting systems, cannot maintained endlessly. This wake-related help explaining