At concentrations that produce psychedelic effects, nitrous oxide reduces the functional differentiation—the distinctness of activity patterns—within frontoparietal and somatomotor cortical networks. This suggests that the gas alters brain network organization, potentially contributing to its consciousness-altering properties. The finding points to a neural mechanism underlying the non-ordinary state induced by nitrous oxide, involving reduced specialization of key brain regions.
Psychedelics like 5-MeO-DMT induce a dissociated brain state that combines features of waking and sleep, rather than a purely psychological change. In freely moving adult male mice, chronic neocortical recordings and pupillometry showed that the drug produces prominent slow oscillations in the cortex and marked pupil dilation while animals remain awake and moving. REM sleep was initially suppressed but overcompensated in the following 48 hours. When given immediately after sleep deprivation, 5-MeO-DMT reduced the subsequent rebound of slow-wave activity. This dissociated state may underlie psychedelic effects such as dream-like hallucinations and reopening of critical periods for plasticity.
A specific type of inhibitory neuron in the orbitofrontal cortex, parvalbumin-expressing (PV) interneurons, helps regulate social behavior by influencing the activity of the default mode network, a set of brain regions active during rest and self-referential thought. The study demonstrates that these neurons modulate social interaction through their effects on network-level brain dynamics.
The abstract describes how visuoaffective day residue—lingering visual and emotional impressions from the day—appears during hypnagogia, the transitional state between wakefulness and sleep. This process involves sequential interactions between both brain hemispheres, engaging cortical, subcortical, and cerebellar structures. The work outlines a neural mechanism for how daily experiences reemerge in the hypnagogic state.