Anesthesiology
February 6, 2020
Andria Pelentritou, Levin Kuhlmann, John Cormack et al.
15 citations
Xenon and nitrous oxide produce different patterns of brain oscillatory power changes, depending on the gas and the recording method. Xenon increased low-frequency delta and theta power only at loss of responsiveness (delta: 208.3%, theta: 107.4% in MEG; delta: 260.3%, theta: 116.3% in EEG). Nitrous oxide increased high-frequency gamma power (low gamma: 46.3%, high gamma: 45.7% in MEG) and reduced frontal alpha power at 0.75 MACawake in MEG (44.4% reduction) and at 0.50 MACawake in EEG (44.0% reduction). The findings show no clear universal features of action for these two gaseous anesthetics, and differences between MEG and EEG must be considered for accurate brain state monitoring during anesthesia.
bioRxiv (Cold Spring Harbor Laboratory)
March 9, 2019
Andria Pelentritou, Levin Kuhlmann, John Cormack et al.
1 citation
preprint
Equivalent stepwise subanesthetic doses of the NMDA-antagonists nitrous oxide (N2O) and xenon (Xe) produce distinct, frequency-dependent changes in cortical oscillatory source power, measured with simultaneous magnetoencephalography (MEG) and electroencephalography (EEG). At the highest Xe concentration (42%, 1.30 MAC-awake), delta and theta band power significantly increased in both MEG and EEG. N2O administration reduced frontal alpha power more strongly than equivalent Xe doses. N2O alone increased MEG (but not EEG) high-frequency gamma power, with occipital low gamma and widespread high gamma rises. These results demonstrate divergent MEG and EEG signatures of dissociative anesthesia.
bioRxiv (Cold Spring Harbor Laboratory)
March 18, 2026
Jacinthe Cataldi, Andria Pelentritou, Sophie Schwartz et al.
The brain continuously processes signals from the outside world and from inside the body. How this balance shifts across different states of consciousness is not well understood. This study measured brain responses to external sounds (auditory evoked potentials) and to heartbeats (heartbeat evoked potentials) in 25 healthy participants during wakefulness and during two types of REM sleep: tonic REM and phasic REM, which have progressively lower responsiveness to the environment. Auditory responses decreased from wakefulness to tonic REM and were smallest during phasic REM. Heartbeat responses remained strong across REM sleep and were even larger than during wakefulness.
Journal of Neural Engineering
April 11, 2025
Rick Evertz, Andria Pelentritou, John Cormack et al.
Resting EEG activity typically resembles a filtered random process, and alpha band (8-13 Hz) oscillations can be modeled as independent, stochastically driven relaxation oscillators. This study tested whether changes in alpha band power and spectral slope during anesthesia with xenon and nitrous oxide—both NMDA receptor antagonists—could be explained by alterations in the distribution of alpha band damping rates. In participants receiving step-level increases of xenon (n=24) or nitrous oxide (n=20), both agents produced dose-dependent reductions in alpha power and spectral slope (15-40 Hz), accounted for by increased mean alpha band damping.
Communications Biology
September 30, 2025
Yun Zhao, Naotsugu Tsuchiya, Mario Boley et al.
Consciousness depends on complex brain structures and processes, but how it is regulated neurobiologically is uncertain. Using magnetoencephalography (MEG) data from 15 participants under Xenon-induced anesthesia, researchers developed interconnected neural mass models to infer time-evolving regional neurophysiological variables and inter-regional connectivity strengths. Significant correlations emerged between consciousness levels and connectivity, especially in posterior parietal, occipital, and prefrontal regions. Results support a parietal, rather than frontal, network backbone for global consciousness. Reductions in consciousness were linked to stabilized cortical dynamics, reflected by changes in the system's eigenmodes. This framework offers a time-resolved perspective on neural mechanisms during altered states.
Journal of visualized experiments : JoVE
January 13, 2018
Andria Pelentritou, Levin Kuhlmann, John Cormack et al.
Inhaling the gaseous anesthetics nitrous oxide (N2O) and xenon (Xe) allows study of brain activity during unconsciousness via simultaneous magnetoencephalography (MEG) and electroencephalography (EEG). Healthy male participants received step-wise increasing concentrations of Xe (8, 16, 24, 42%) and N2O (16, 32, 47%) in a repeated measures cross-over design. An auditory continuous performance task tracked responsiveness. The protocol, refined over multiple sessions, details subject recruitment, equipment setup, data collection, and basic analysis. Results show sensor-level raw data, spectral topography, minimal head movements, and level-dependent effects on auditory evoked responses. The method can be adapted for volatile and intravenous anesthetics to advance understanding of macro-scale anesthesia mechanisms.