Local Gamma Activity During Non-REM Sleep in the Context of Sensory Evoked K-Complexes.

摘要: K-complexes (KCs) and Sleep Slow Oscillations (SSOs) are the EEG expression of neuronal bistability during deeper stages Non-REM sleep. They characterized by a deep negative deflection lasting about half-a-second, sustained, at cortical level, widespread synchronized hyperpolarization (i.e. electrical silence). The phase is followed period intense firing depolarization phase) resulting in large positive (lasting 0.5 seconds) concurrent high frequency activity spindles). Both KCs SSOs rather than being “local” phenomena, propagate over sections cortex. These features suggest that large-scale network phenomenon, possibly driven propagating excitatory involving wide populations neurons. We have recently shown include bump preceding peak for sensory-evoked this coincides with P200 wave. demonstrated has sensory-modality specific localization, as it firstly elicited primary sensory areas related to stimulus, which turn receive projections from thalamic core. observed acts hypothesized could play key role inducing opening K+ channels, hence hyperpolarization. Here we demonstrate sustained high-frequency excitation bringing further support its triggering bistability. show higher power density gamma band compared P900 coherently all modalities, confirm latter wave crowned sigma-beta bands. Finally, characterize level terms spatial localization temporal dynamics, demonstrating emerges stimulus-specific travels mantle spreading towards fronto-central associative fading concurrently N550 onset.