Reduced brain connectivity in frontal cortex linked to propofol-induced loss of consciousness
News Apr 15, 2016
A new study shows that loss of responsiveness induced by propofol, a commonly used anesthetic, is associated with greatly diminished brain connectivity in the frontal cortex and significant changes in resting state brain networks.
The study, based on a novel method for constructing total brain connectivity maps and comparing them with results obtained for resting state networks, is published in Brain Connectivity.
Pieter Guldenmund and coauthors from University of Liège and CHR Hospital Citadelle (Liège, Belgium), National University of Colombia and Central University of Colombia (Bogotá), University of Western Ontario (London, Canada), and University of Wisconsin (Madison), used resting-state functional magnetic resonance imaging (fMRI) to determine changes in resting state brain networks, total brain connectivity, and mean oscillation frequencies of the regional blood oxygenation level dependent (BOLD) signal associated with propofol-induced mild sedation and loss of consciousness. The researchers conclude that diminished connectivity in the frontal lobes plays an important role in propofol-induced loss of responsiveness.
"Very little is understood about the biological mechanism of how an anesthetic produces sedation and loss of consciousness, especially in the brain," says Christopher Pawela, PhD, Co-Editor-in-Chief of Brain Connectivity and Assistant Professor of Anesthesiology, Medical College of Wisconsin. "Pieter Guldenmund and his colleagues have produced an elegant study using resting-state functional connectivity MRI to implicate the frontal lobes in the mechanism of action of propofol in the brain."
Note: Material may have been edited for length and content. For further information, please contact the cited source.
Guldenmund P et al. Propofol-Induced Frontal Cortex Disconnection: A Study of Resting-State Networks, Total Brain Connectivity, and Mean BOLD Signal Oscillation Frequencies. Brain Connectivity, Published March 31 2016. doi: 10.1089/brain.2015.0369
Neurons in the human brain receive electrical signals from thousands of other cells, and long neural extensions called dendrites play a critical role in incorporating all of that information. Using hard-to-obtain samples of human brain tissue, MIT neuroscientists have now discovered that human dendrites have different electrical properties from those of other species.