Cell reports
April 23, 2024
Adeeti Aggarwal, Jennifer Luo, Helen Chung et al.
17 citations
Traveling cortical waves in the 3-6 Hz range coordinate neuronal activity across visual and parietal cortex only in brain states where perception is possible. In awake mice, visual stimuli reset spontaneous waves, producing stimulus-evoked feedback waves that entrain neurons. Under anesthesia, visual stimuli fail to disrupt spontaneous waves. During ketamine-induced dissociation, spontaneous waves themselves traverse the cortex caudally and entrain neurons, mimicking the stimulus-evoked pattern seen in wakefulness. Thus, coordinated neuronal assemblies orchestrated by traveling waves emerge in states that allow perception, but only the awake state reliably links this coordination to external visual input.
The Neuroscientist
December 26, 2025
Kallol Bera, Loren L. Looger, Alex Proekt et al.
5 citations
Ketamine, an anesthetic that produces dissociative anesthesia—characterized by perceptual detachment, analgesia, and altered consciousness—also acts as a rapid antidepressant at low doses and serves as a tool to study consciousness and neuropsychiatric disorders. Its effects stem from actions on cortical circuits: blocking NMDA receptors and HCN1 channels, disinhibiting pyramidal neurons, and altering thalamocortical connectivity. The review synthesizes findings from pharmacology, cell-specific imaging, and systems neuroscience to explain how ketamine alters cortical dynamics to drive dissociation. It also explores the possibility that ketamine enters intracellular compartments, modulating neuronal excitability, signaling, and epigenetic state after a single dose. Understanding these processes may inform new treatments for treatment-resistant depression and the study of consciousness.
The Journal of neuroscience : the official journal of the Society for Neuroscience
May 14, 2025
Diego G Dávila, Andrew McKinstry-Wu, Max B Kelz et al.
5 citations
During wakefulness, people respond to external stimuli, while in dreams or drug-induced dissociated states, vivid internal experiences occur with reduced perception of the outside world. The brain's activity near a critical point between damped and exploding oscillations is linked to conscious experience, and this signature appears in both normal wakefulness and dissociative states but not in dreamless sleep or anesthesia. Using high-density EEG in human male volunteers given escalating ketamine doses, activity became progressively more stable, especially at higher frequencies, as dissociative symptoms increased. This stabilization correlated with reduced ability to perceive external stimuli, not with conscious experience itself. Combining statistical and dynamical measures of criticality may help distinguish wakefulness, dissociation, and unconsciousness.