CCS Scientific Director George Mashour publishes new paper in eLife that examines how the brain recovers from unconsciousness after anesthesia
Understanding how the brain recovers from unconsciousness can inform neurobiological theories of consciousness and guide clinical investigation. To address this question, we conducted a multicenter study of 60 healthy humans, half of whom received general anesthesia for 3 hr and half of whom served as awake controls. We administered a battery of neurocognitive tests and recorded electroencephalography to assess cortical dynamics. We hypothesized that recovery of consciousness and cognition is an extended process, with differential recovery of cognitive functions that would commence with return of responsiveness and end with return of executive function, mediated by prefrontal cortex. We found that, just prior to the recovery of consciousness, frontal-parietal dynamics returned to baseline. Consistent with our hypothesis, cognitive reconstitution after anesthesia evolved over time. Contrary to our hypothesis, executive function returned first. Early engagement of prefrontal cortex in recovery of consciousness and cognition is consistent with global neuronal workspace theory.
Four-year 1.4M grant award by NIH/NIGMS to PI Dr. Tony Hudetz to continue studying the neural mechanism by which general anesthetics modulate consciousness.
The overall goal of this research project is to investigate local neuronal mechanisms in the cerebral cortex associated with complex, natural sensory experience and to determine how general anesthetics may alter sensory-specific contents of consciousness. Our general hypothesis is that anesthetic modulation of consciousness is closely tied to the modification of specific spatiotemporal patterns of neuronal activity in local cortical circuits. We will test our hypothesis in the rat visual and association cortex as a model system in vivo.
Huels, E et al, “Neural Correlates of the Shamanic State of Consciousness". Front Neurosci 2021
Parkar, A et al, “Carbachol and nicotine in prefrontal cortex have differential effects on sleep-wake states". Front Neurosci 2020
Mawla, I et al, “Greater somatosensory afference with acupuncture increases primary somatosensory connectivity and alleviates fibromyalgia pain via insular GABA: A randomized neuroimaging trial". Arthritis Rheumatol 2020
Lee, H et al, “Differential effect of anesthesia on visual cortex neurons with diverse population coupling". Neuroscience 2020
Larkin, T et al, “Altered network architecture of functional brain communities in chronic nociplastic pain". Neuroimage 2020
Mahdid, Y et al, “Assessing the quality of wearable EEG systems using functional connectivity". IEEE Access 2020
Zilio, F et al, “Are intrinsic neuronal timescales related to sensory processing? Evidence from abnormal behavioral states". Neuroimage 2020
Lee, H et al, “State-Dependent Cortical Unit Activity Reflects Dynamic Brain State Transitions in Anesthesia". J Neurosci 2020
Vlisides, P et al, “Deep Anaesthesia". Lancet 2020
Kallionpää, R et al, “Alpha band frontal connectivity is a state-specific electroencephalographic correlate of unresponsiveness during exposure to dexmedetomidine and propofol". Br J Anaesth 2020
Brito, M et al, "State-Dependent and Bandwidth-Specific Effects of Ketamine and Propofol on Electroencephalographic Complexity in Rats". Front Syst Neurosci 2020
NEUROSCI 704 – Course Description: The nature and the neural basis of consciousness is a foundational question in neuroscience. As a scientific inquiry, it speaks to the existence of reality as we perceive it, and from a translational and therapeutic perspective, a fundamental understanding of the biological basis of consciousness has implications for disorders ranging from psychiatric disorders to the disorders of consciousness. In this course, we will start with a brief overview of the current neuroscientific frameworks and theories to study consciousness, and then as we move forward, will discuss the recent literature on the neurobiology of physiological (sleep), pharmacological (anesthesia, psychedelic states), and pathological states (coma, vegetative state) of consciousness. The students will participate in discussion and presentation of recent relevant literature.
Contacts: Dinesh Pal and Giancarlo Vanini
This lecture has been postponed. Professor Beverley A. Orser from the University of Toronto will deliver the 5th annual Domino Lecture sponsored by CCS.
To view this day-long symposium with national and international experts, please see: https://www.youtube.com/watch?v=WZcF75RtnvQ&feature=youtu.be