Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.
Neuroscience letters June 9, 2017 Ji-Ho Ryu, Pil-Jong Kim, Hong-Gee Kim et al.
In healthy adults inhaling nitrous oxide to induce sedation while maintaining consciousness, electroencephalography revealed that functional connectivity between frontal and parietal brain regions is significantly altered. Low-frequency power increased in frontal regions during sedation and reversed after discontinuation. Granger causality analysis showed that feedback and feedforward connections changed differently across EEG frequency bands. Specifically, spectral Granger causality in the theta, alpha, and beta bands from parietal to frontal directions significantly decreased during sedation, while the reverse direction showed no significant change. This reduced parietal-to-frontal interaction may underlie the sedated state and cognitive impairment.