Chellappa, Sarah L.Gaggioni, GiuliaLy, Julien Q. M.Papachilleos, SoteriosBorsu, ChloeBrzozowski, AlexandreRosanova, MarioSarasso, SimoneLuxen, AndreMiddleton, BenitaArcher, Simon N.Dijk, Derk-JanMassimini, MarcelloMaquet, PierrePhillips, ChristopheMoran, Rosalyn J.Vandewalle, Gilles2019-01-222019-01-222016-09-212045-232233661http://hdl.handle.net/10919/86834Several neuropsychiatric and neurological disorders have recently been characterized as dysfunctions arising from a 'final common pathway' of imbalanced excitation to inhibition within cortical networks. How the regulation of a cortical E/I ratio is affected by sleep and the circadian rhythm however, remains to be established. Here we addressed this issue through the analyses of TMS-evoked responses recorded over a 29 h sleep deprivation protocol conducted in young and healthy volunteers. Spectral analyses of TMS-evoked responses in frontal cortex revealed non-linear changes in gamma band evoked oscillations, compatible with an influence of circadian timing on inhibitory interneuron activity. In silico inferences of cell-to-cell excitatory and inhibitory connectivity and GABA/Glutamate receptor time constant based on neural mass modeling within the Dynamic causal modeling framework, further suggested excitation/inhibition balance was under a strong circadian influence. These results indicate that circadian changes in EEG spectral properties, in measure of excitatory/inhibitory connectivity and in GABA/glutamate receptor function could support the maintenance of cognitive performance during a normal waking day, but also during overnight wakefulness. More generally, these findings demonstrate a slow daily regulation of cortical excitation/inhibition balance, which depends on circadian-timing and prior sleep-wake history.13application/pdfenCreative Commons Attribution 4.0 Internationaltranscranial magnetic stimulationsynaptic plasticitybrain responseshuman sleephomeostasisexcitabilityinventorycortexphaseeegArticle - Refereedhttps://doi.org/10.1038/srep33661627651114