Neural assemblies coordinated by cortical waves are associated with waking and hallucinatory brain states.

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.

Study at a glance

Abstract

The relationship between sensory stimuli and perceptions is brain-state dependent: in wakefulness, suprathreshold stimuli evoke perceptions; under anesthesia, perceptions are abolished; and during dreaming and in dissociated states, percepts are internally generated. Here, we exploit this state dependence to identify brain activity associated with internally generated or stimulus-evoked perceptions. In awake mice, visual stimuli phase reset spontaneous cortical waves to elicit 3-6 Hz feedback traveling waves. These stimulus-evoked waves traverse the cortex and entrain visual and parietal neurons. Under anesthesia as well as during ketamine-induced dissociation, visual stimuli do not disrupt spontaneous waves. Uniquely, in the dissociated state, spontaneous waves traverse the cortex caudally and entrain visual and parietal neurons, akin to stimulus-evoked waves in wakefulness. Thus, coordinated neuronal assemblies orchestrated by traveling cortical waves emerge in states in which perception can manifest. The awake state is privileged in that this coordination is reliably elicited by external visual stimuli.