Nature communications
August 15, 2024
Davor Curic, Donovan M Ashby, Alexander McGirr et al.
9 citations
Brain activity during quiet wakefulness exhibits scale-free patterns of coordinated neuronal firing, thought to reflect a universal operating mechanism. This study examined how three common anesthetics—isoflurane, pentobarbital, and ketamine—at multiple doses alter these patterns in the mouse cortex using calcium imaging. Low doses largely preserved scale-free statistics, but surgical-plane anesthesia disrupted critical avalanche dynamics, producing multiple abnormal modes. The findings reveal distinct pathways away from the default critical state, depending on the anesthetic and individual responses, suggesting a complex relationship between criticality and consciousness.
Physical review. E
November 2, 2023
Anja Rabus, Davor Curic, Victorita E. Ivan et al.
8 citations
The brain may maintain optimal information transmission even when its functional connectivity is drastically altered. The psychedelic compound ibogaine, which induces an altered state of consciousness, fundamentally changes functional connectivity in the retrosplenial cortex of mice. Despite these changes, the scale-free statistics of movement and of neuronal avalanches among behaviorally related neurons remain largely unaltered. This suggests that the propagation of information within biological neural networks is robust to changes in the functional organization of neuronal subpopulations, offering a new perspective on how adaptive functional networks may support optimal information transmission.
Biological psychiatry global open science
January 1, 2024
Victorita E Ivan, David P Tomàs-Cuesta, Ingrid M Esteves et al.
7 citations
Ibogaine, a psychedelic compound, destabilizes the cognitive map in the retrosplenial cortex of mice when they must infer their position between tactile landmarks. Using two-photon microscopy, researchers recorded neural activity in head-fixed mice running on a treadmill before and after ibogaine injection (40 mg/kg intraperitoneally). The drug increased neural activity rates, disrupted correlation structure, and heightened responses to cues, while leaving the size-frequency distribution of network activity events largely unchanged. These findings suggest that psychedelics disrupt representations that constrain neocortical activity, increasing neural signaling entropy. The loss of position encoding between landmarks resembles effects of hippocampal impairment, indicating that disruption of cognitive maps may contribute to discoordinated neocortical activity in psychedelic states.