Largest scale dissociation of brain activity at propofol-induced loss of consciousness
| Autor: | Irina Adalid, Joan Deus, Luis Moltó, Laura Blanco-Hinojo, Lluís Gallart, Jesús Pujol, Juan L. Fernández-Candil, E. Vilà, S. Pacreu, Gerard Martínez-Vilavella, Víctor Pérez-Sola |
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| Rok vydání: | 2020 |
| Předmět: |
Dissociation (neuropsychology)
Consciousness Brain activity and meditation media_common.quotation_subject Dissociative Disorders Unconsciousness Arousal 03 medical and health sciences 0302 clinical medicine Physiology (medical) Neural Pathways medicine Humans Propofol Default mode network 030304 developmental biology media_common 0303 health sciences medicine.diagnostic_test Brain Magnetic Resonance Imaging medicine.anatomical_structure Cerebral cortex Neurology (clinical) medicine.symptom Psychology Functional magnetic resonance imaging Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Sleep. 44 |
| ISSN: | 1550-9109 0161-8105 |
| Popis: | The brain is a functional unit made up of multilevel connected elements showing a pattern of synchronized activity that varies in different states. The wake–sleep cycle is a major variation of brain functional condition that is ultimately regulated by subcortical arousal- and sleep-promoting cell groups. We analyzed the evolution of functional MRI (fMRI) signal in the whole cortex and in a deep region including most sleep- and wake-regulating subcortical nuclei at loss of consciousness induced by the hypnotic agent propofol. Optimal data were obtained in 21 of the 30 healthy participants examined. A dynamic analysis of fMRI time courses on a time-scale of seconds was conducted to characterize consciousness transition, and functional connectivity maps were generated to detail the anatomy of structures showing different dynamics. Inside the magnet, loss of consciousness was marked by the participants ceasing to move their hands. We observed activity synchronization after loss of consciousness within both the cerebral cortex and subcortical structures. However, the evolution of fMRI signal was dissociated, showing a transient reduction of global cortico-subcortical coupling that was restored during the unconscious state. An exception to cortico-subcortical decoupling was a brain network related to self-awareness (i.e. the default mode network) that remained connected to subcortical brain structures. Propofol-induced unconsciousness is thus characterized by an initial, transitory dissociated synchronization at the largest scale of brain activity. Such cortico-subcortical decoupling and subsequent recoupling may allow the brain to detach from waking activity and reorganize into a functionally distinct state. |
| Databáze: | OpenAIRE |
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