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
May 18, 2026
Kyna Conn, Ngok Wong, Serenay Sunnetci et al.
A single dose of psilocybin (1.5 mg/kg) in female rats enhanced cognitive flexibility in several learning tasks by amplifying dopamine signals in the nucleus accumbens. The drug increased learning rates and reduced reliance on prior expectations, leading to faster reversal learning. However, calorie restriction and prior exposure to activity-based anorexia (ABA) reduced these benefits. Calorie restriction shifted the timing of psilocybin's effect on reversal learning and increased neural activity in the nucleus accumbens. Prior ABA exposure eliminated improvements in discrimination accuracy and trended toward worsening reversal learning, likely due to reduced cortical 5-HT2A receptor availability. The results show that nutritional state and history of anorexia-like behavior critically moderate psilocybin's cognitive effects.
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.
PloS one
January 1, 2013
Levin Kuhlmann, Brett L Foster, David T J Liley
Nitrous oxide (N2O), an NMDA receptor antagonist, reduces parietal network functional connectivity by about 50% and frontal network connectivity by about 10%, as measured by EEG. Parietal reductions were detected only with a surface Laplacian derivation, indicating superficial cortical networks are most affected, while frontal reductions were detected with a common-reference derivation, suggesting widespread perturbations. These findings support the idea that different anesthetic agents may produce similar final network changes underlying reduced consciousness.