Intrinsic Organization of the Anesthetized Brain
- 25 July 2012
- journal article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 32 (30), 10183-10191
- https://doi.org/10.1523/jneurosci.1020-12.2012
Abstract
The neural mechanism of unconsciousness has been a major unsolved question in neuroscience despite its vital role in brain states like coma and anesthesia. The existing literature suggests that neural connections, information integration, and conscious states are closely related. Indeed, alterations in several important neural circuitries and networks during unconscious conditions have been reported. However, how the whole-brain network is topologically reorganized to support different patterns of information transfer during unconscious states remains unknown. Here we directly compared whole-brain neural networks in awake and anesthetized states in rodents. Consistent with our previous report, the awake rat brain was organized in a nontrivial manner and conserved fundamental topological properties in a way similar to the human brain. Strikingly, these topological features were well maintained in the anesthetized brain. Local neural networks in the anesthetized brain were reorganized with altered local network properties. The connectional strength between brain regions was also considerably different between the awake and anesthetized conditions. Interestingly, we found that long-distance connections were not preferentially reduced in the anesthetized condition, arguing against the hypothesis that loss of long-distance connections is characteristic to unconsciousness. These findings collectively show that the integrity of the whole-brain network can be conserved between widely dissimilar physiologic states while local neural networks can flexibly adapt to new conditions. They also illustrate that the governing principles of intrinsic brain organization might represent fundamental characteristics of the healthy brain. With the unique spatial and temporal scales of resting-state fMRI, this study has opened a new avenue for understanding the neural mechanism of (un)consciousness.This publication has 40 references indexed in Scilit:
- Coma and consciousness: Paradigms (re)framed by neuroimagingNeuroImage, 2012
- Impact of in-scanner head motion on multiple measures of functional connectivity: Relevance for studies of neurodevelopment in youthNeuroImage, 2012
- Weight-conserving characterization of complex functional brain networksNeuroImage, 2011
- Functional Connectivity in the Brain: Effects of AnesthesiaThe Neuroscientist, 2011
- Comparison of α-chloralose, medetomidine and isoflurane anesthesia for functional connectivity mapping in the ratMagnetic Resonance Imaging, 2010
- Performance of modularity maximization in practical contextsPhysical Review E, 2010
- Default network connectivity reflects the level of consciousness in non-communicative brain-damaged patientsBrain, 2009
- Functional Connectivity of the Macaque Brain across Stimulus and Arousal StatesJournal of Neuroscience, 2009
- Variations in extracellular levels of dopamine, noradrenaline, glutamate, and aspartate across the sleep–wake cycle in the medial prefrontal cortex and nucleus accumbens of freely moving ratsJournal of Neuroscience Research, 2005
- The Septohippocampal System Participates in General AnesthesiaJournal of Neuroscience, 2002