Noradrenergic activity as a key target in modulating consciousness.
Scientific Reports March 10, 2026 Olympia Karampela, Aurelie Fontan, Lenita Lindgren et al.
Noradrenergic activity plays a key role in conscious visuospatial processing, distinct from general arousal effects. Two experiments—one using the sedative Dexmedetomidine (which targets α2A noradrenergic receptors) and another using sleep deprivation—both selectively altered brain activity (fMRI BOLD signal) during conscious processing, unlike the sedative Propofol, which affects both conscious and unconscious processing. However, the two methods produced opposite effects on visuospatial bias: Dexmedetomidine reduced leftward bias, while sleep deprivation increased leftward bias. The sleep deprivation effect was linked to an unexpected increase in sympathetic drive, indicated by heightened central autonomic network activity and heart rate, suggesting increased noradrenaline levels during task performance. These findings highlight noradrenergic activity as a target for studying consciousness.