[Quantified EEG and CNV changes during inhalation of nitrous oxide].
Revue d'electroencephalographie et de neurophysiologie clinique November 1, 1982 M Timsit-Berthier, H Mantanus, D Dethier et al.
Inhaling nitrous oxide produces a mix of depressive and activating effects on the central nervous system. In 9 volunteers, 25% and 50% nitrous oxide caused muscle relaxation, psychomotor slowing, and a shift in EEG toward slower waves with less alpha and more theta and delta activity, along with reduced amplitude of auditory evoked potential components. At the same time, it heightened sensory perceptions, caused perceptual illusions, and maintained high and prolonged contingent negative variation amplitude, suggesting CNS activation. This dual effect indicates a dissociative action at different levels of the central nervous system.