title: Brain Connectivity Dissociates Responsiveness from Drug Exposure during Propofol-Induced Transitions of Consciousness.
abstract: Accurately measuring the neural correlates of consciousness is a grand challenge for neuroscience. Despite theoretical advances, developing reliable brain measures to track the loss of reportable consciousness during sedation is hampered by significant individual variability in susceptibility to anaesthetics. We addressed this challenge using high-density electroencephalography to characterise changes in brain networks during propofol sedation. Assessments of spectral connectivity networks before, during and after sedation were combined with measurements of behavioural responsiveness and drug concentrations in blood. Strikingly, we found that participants who had weaker alpha band networks at baseline were more likely to become unresponsive during sedation, despite registering similar levels of drug in blood. In contrast, phase-amplitude coupling between slow and alpha oscillations correlated with drug concentrations in blood. Our findings highlight novel markers that prognosticate individual differences in susceptibility to propofol and track drug exposure. These advances could inform accurate drug titration and brain state monitoring during anaesthesia.
authors.affiliation: Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.|Medical Research Council, Cognition and Brain Sciences Unit, Cambridge, United Kingdom.
authors.forename: Srivas
authors.initials: S
authors.lastname: Chennu
authors.affiliation: Warwick Medical School, University of Warwick, Coventry, United Kingdom.
authors.forename: Stuart
authors.initials: S
authors.lastname: O'Connor
authors.affiliation: Division of Anaesthesia, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Ram
authors.initials: R
authors.lastname: Adapa
authors.affiliation: Division of Anaesthesia, University of Cambridge, Cambridge, United Kingdom.
authors.forename: David K
authors.initials: DK
authors.lastname: Menon
authors.affiliation: Medical Research Council, Cognition and Brain Sciences Unit, Cambridge, United Kingdom.|Department of Psychology, University of Cambridge, Cambridge, United Kingdom.
authors.forename: Tristan A
authors.initials: TA
authors.lastname: Bekinschtein
mesh_terms: D000328:Adult; D058256:Brain Waves / Q000187:drug effects / Q000502:physiology; D019295:Computational Biology; D003243:Consciousness / Q000187:drug effects* / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives; D008297:Male; D015742:Propofol / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D015742:Propofol