Dynamic neural remapping across the sleep-wake cycle: A mechanistic link between sensory re-organisation and GABA (360G-Wellcome-209086_Z_17_Z)

Across a single day, we undergo behavioral, physiological and neurochemical changes, from vigilant wakefulness to unconscious sleep. Despite the loss of consciousness, sensory processing continues in sleep. Attempts to assess the degree to which sensory processing differs between wakefulness and sleep have yielded contradicting results with studies showing greater, smaller or comparable responses to the same stimuli when comparing the two states. Hence, it remains unclear precisely how sensory processing is modulated throughout the sleep-wake cycle. Most studies have focused on responses to specific stimuli, neglecting the relationship between different stimuli. We suggest a new comprehensive approach to elucidate how vigilance state dynamically shapes sensory processing, by combining electroencephalography (EEG), functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS) together with state-of-the-art computational tools, measuring neural distances between stimuli to quantify sensory remapping across the sleep-wake cycle. We hypothesize that gamma-Aminobutyric Acid (GABA), an inhibitory neurotransmitter implicated in sleep regulation and correlated with sensory sensitivity, has a central role in sensory remapping. Thus, in this research proposal, the key goals are:(i) to elucidate the temporal and spatial dynamics of sensory remapping throughout the sleep-wake cycle, and (ii) to investigate whether sensory remapping across the sleep-wake cycle is GABA-dependent.