scholarly journals Recovery of consciousness and cognition after general anesthesia in humans

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
George A Mashour ◽  
Ben JA Palanca ◽  
Mathias Basner ◽  
Duan Li ◽  
Wei Wang ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Executive Function ◽  
General Anesthesia ◽  
Clinical Investigation ◽  
Cortical Dynamics ◽  
Healthy Humans ◽  
Neurocognitive Tests ◽  
The Brain ◽  
Recovery Of Consciousness ◽  
Over Time

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 three hours 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.

scholarly journals Recovery of Consciousness and Cognition after General Anesthesia in Humans

2020 ◽  
Author(s):  
George A. Mashour ◽  
Ben J.A. Palanca ◽  
Mathias Basner ◽  
Duan Li ◽  
Wei Wang ◽  
...  
Keyword(s):  
Executive Function ◽  
Cognitive Function ◽  
General Anesthesia ◽  
Healthy Human ◽  
Cortical Dynamics ◽  
Healthy Humans ◽  
Neurocognitive Tests ◽  
Wake Patterns ◽  
Normal Sleep ◽  
Anesthetic Exposure

AbstractUnderstanding how consciousness and cognitive function return after a major perturbation is important clinically and neurobiologically. To address this question, we conducted a three-center study of 30 healthy humans receiving general anesthesia at clinically relevant doses for three hours. We administered a pre- and post-anesthetic battery of neurocognitive tests, recorded continuous electroencephalography to assess cortical dynamics, and monitored sleep-wake activity before and following anesthetic exposure. We hypothesized that cognitive reconstitution would be a process that evolved over time in the following sequence: attention, complex scanning and tracking, working memory, and executive function. Contrary to our hypothesis, executive function returned first and electroencephalographic analyses revealed that frontal cortical dynamics recovered faster than posterior cortical dynamics. Furthermore, actigraphy indicated normal sleep-wake patterns in the post-anesthetic period. These recovery patterns of higher cognitive function and arousal states suggest that the healthy human brain is resilient to the effects of deep general anesthesia.

scholarly journals Exploring the Inner Workings of Neuron Circuits That Exhibit Persistent Activity To Explain How Working Memory and Executive Function Are Implemented in The Brain

2021 ◽  
Author(s):  
Paul Gomez
Keyword(s):  
Decision Making ◽  
Working Memory ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
Memory Task ◽  
Persistent Activity ◽  
Storage Mechanism ◽  
Minimum Number ◽  
Task Processing ◽  
The Brain

In this research we explore in detail how a phenomenon called sustained persistent activity is achieved by circuits of interconnected neurons. Persistent activity is a phenomenon that has been extensively studied (Papoutsi et al. 2013; Kaminski et. al. 2017; McCormick et al. 2003; Rahman, and Berger, 2011). Persistent activity consists in neuron circuits whose spiking activity remains even after the initial stimuli are removed. Persistent activity has been found in the prefrontal cortex (PFC) and has been correlated to working memory and decision making (Clayton E. Curtis and Daeyeol Lee, 2010). We go beyond the explanation of how persistent activity happens and show how arrangements of those basic circuits encode and store data and are used to perform more elaborated tasks and computations. The purpose of the model we propose here is to describe the minimum number of neurons and their interconnections required to explain persistent activity and how this phenomenon is actually a fast storage mechanism required for implementing working memory, task processing and decision making.

The Neuroscience of Learning Agility

2021 ◽  
pp. 118-142
Author(s):  
Kim E. Ruyle
Keyword(s):  
Emotional Intelligence ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
Limbic System ◽  
Brain Regions ◽  
Learning Agility ◽  
Attention Networks ◽  
The Relationship ◽  
The Brain

“The Neuroscience of Learning Agility” explores the relationship between neurobiology and learning agility. It provides an overview of the organization of the brain, focusing on the roles of the limbic system and the prefrontal cortex and how these particular brain regions relate to personality, executive function, and the metacompetencies of emotional intelligence and learning agility. The neuroscience of learning is discussed, including the brain’s attention networks, neuroplasticity, and biological underpinnings of memory. An argument is posited that the brain’s perceptions of threats directly impacts one’s personality and, by extension, influences one’s level of learning agility. The chapter concludes by providing neuroscience-based suggestions for developing learning agility.

Ascorbic Acid Does Not Influence Consciousness Recovery After Anesthesia

2008 ◽  
Vol 10 (3) ◽  
pp. 292-298 ◽  
Author(s):  
Henry C. Talley V ◽  
Mona N. Wicks ◽  
Michael Carter ◽  
Brad Roper
Keyword(s):  
Ascorbic Acid ◽  
General Anesthesia ◽  
Repeated Measures ◽  
General Anesthetic ◽  
Plasma Ascorbic Acid ◽  
Anesthetic Agents ◽  
Significant Relationships ◽  
Synaptic Receptors ◽  
The Brain ◽  
Recovery Of Consciousness

Several studies have examined the influence of general anesthesia on changes in consciousness and unconscious cognitive processes. However, much remains to be learned about potential moderators of general anesthetic agents, such as antioxidants including ascorbic acid, and their influence on the recovery of consciousness following general anesthesia. General anesthesia potentially affects plasma ascorbic acid levels and may impair consciousness during the postoperative period; however, published literature regarding these relationships is equivocal. Ascorbic acid is important for brain function and may be related to the return of postoperative consciousness through action on the synaptic receptors in the brain. This study was designed as a pretest—posttest repeated measures investigation. Ascorbic acid levels were measured at four time periods in patients (N = 50) undergoing surgery and general anesthesia. Following surgery, patients were administered a paper-and-pencil measure of concentration that served as an index of post-anesthesia consciousness. The results suggest that changes occur in plasma ascorbic acid levels at different time points during the anesthesia regimen in nonemergent surgical patients. No statistically significant relationships were found between plasma ascorbic acid levels and improved post-anesthesia consciousness, suggesting that ascorbic acid does not influence recovery of consciousness following general anesthesia.

scholarly journals Atomoxetine Enhances Connectivity of Prefrontal Networks in Parkinson’s Disease

2016 ◽  
Vol 41 (8) ◽  
pp. 2171-2177 ◽  
Author(s):  
Robin J Borchert ◽  
Timothy Rittman ◽  
Luca Passamonti ◽  
Zheng Ye ◽  
Saber Sami ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
Executive Functions ◽  
Dorsolateral Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
The Brain

Abstract Cognitive impairment is common in Parkinson’s disease (PD), but often not improved by dopaminergic treatment. New treatment strategies targeting other neurotransmitter deficits are therefore of growing interest. Imaging the brain at rest (‘task-free’) provides the opportunity to examine the impact of a candidate drug on many of the brain networks that underpin cognition, while minimizing task-related performance confounds. We test this approach using atomoxetine, a selective noradrenaline reuptake inhibitor that modulates the prefrontal cortical activity and can facilitate some executive functions and response inhibition. Thirty-three patients with idiopathic PD underwent task-free fMRI. Patients were scanned twice in a double-blind, placebo-controlled crossover design, following either placebo or 40-mg oral atomoxetine. Seventy-six controls were scanned once without medication to provide normative data. Seed-based correlation analyses were used to measure changes in functional connectivity, with the right inferior frontal gyrus (IFG) a critical region for executive function. Patients on placebo had reduced connectivity relative to controls from right IFG to dorsal anterior cingulate cortex and to left IFG and dorsolateral prefrontal cortex. Atomoxetine increased connectivity from the right IFG to the dorsal anterior cingulate. In addition, the atomoxetine-induced change in connectivity from right IFG to dorsolateral prefrontal cortex was proportional to the change in verbal fluency, a simple index of executive function. The results support the hypothesis that atomoxetine may restore prefrontal networks related to executive functions. We suggest that task-free imaging can support translational pharmacological studies of new drug therapies and provide evidence for engagement of the relevant neurocognitive systems.

scholarly journals Generalizable knowledge outweighs incidental details in prefrontal ensemble code over time

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Mark D Morrissey ◽  
Nathan Insel ◽  
Kaori Takehara-Nishiuchi
Keyword(s):  
Prefrontal Cortex ◽  
Time Course ◽  
Knowledge Structure ◽  
Associative Memories ◽  
The World ◽  
Past Experiences ◽  
New Situation ◽  
The Brain ◽  
Over Time ◽  
Context Memory

Memories for recent experiences are rich in incidental detail, but with time the brain is thought to extract latent rules and structures common across past experiences. We show that over weeks following the acquisition of two distinct associative memories, neuron firing in the rat prelimbic prefrontal cortex (mPFC) became less selective for perceptual features unique to each association and, with an apparently different time-course, became more selective for common relational features. We further found that during exposure to a novel experimental context, memory expression and neuron selectivity for relational features immediately generalized to the new situation. These neural patterns offer a window into the network-level processes by which the mPFC develops a knowledge structure of the world that can be adaptively applied to new experiences.

SPECIFIC PROPERTIES OF TUBULIN IN THE PREFRONTAL CORTEX IN CONTROL, SCHIZOPHRENIA AND VASCULAR DEMENTIA

2020 ◽  
pp. 65-71
Author(s):  
Burbaeva G.Sh. ◽  
Androsova L.V. ◽  
Vorobyeva E.A. ◽  
Savushkina O.K.
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Prefrontal Cortex ◽  
Vascular Dementia ◽  
Binding Activity ◽  
Nephelometric Method ◽  
Rate Of Polymerization ◽  
Mental Diseases ◽  
And Control ◽  
The Brain

The aim of the study was to evaluate the rate of polymerization of tubulin into microtubules and determine the level of colchicine binding (colchicine-binding activity of tubulin) in the prefrontal cortex in schizophrenia, vascular dementia (VD) and control. Colchicine-binding activity of tubulin was determined by Sherlinе in tubulin-enriched extracts of proteins from the samples. Measurement of light scattering during the polymerization of the tubulin was carried out using the nephelometric method at a wavelength of 450-550 nm. There was a significant decrease in colchicine-binding activity and the rate of tubulin polymerization in the prefrontal cortex in both diseases, and in VD to a greater extent than in schizophrenia. The obtained results suggest that not only in Alzheimer's disease, but also in other mental diseases such as schizophrenia and VD, there is a decrease in the level of tubulin in the prefrontal cortex of the brain, although to a lesser extent than in Alzheimer's disease, and consequently the amount of microtubules.

Activation of Melanocortin-4 Receptor by a Synthetic Agonist Inhibits Ethanolinduced Neuroinflammation in Rats

2020 ◽  
Vol 25 (45) ◽  
pp. 4799-4805 ◽  
Author(s):  
Osvaldo Flores-Bastías ◽  
Gonzalo I. Gómez ◽  
Juan A. Orellana ◽  
Eduardo Karahanian
Keyword(s):  
Prefrontal Cortex ◽  
Alcohol Consumption ◽  
Ethanol Intake ◽  
Neuroinflammatory Response ◽  
Agonist Peptide ◽  
Melanocortin 4 Receptor ◽  
Tnf Α ◽  
Cord Injury ◽  
High Ethanol ◽  
The Brain

Background: High ethanol intake induces a neuroinflammatory response resulting in the subsequent maintenance of chronic alcohol consumption. The melanocortin system plays a pivotal role in the modulation of alcohol consumption. Interestingly, it has been shown that the activation of melanocortin-4 receptor (MC4R) in the brain decreases the neuroinflammatory response in models of brain damage other than alcohol consumption, such as LPS-induced neuroinflammation, cerebral ischemia, glutamate excitotoxicity, and spinal cord injury. Objectives: In this work, we aimed to study whether MC4R activation by a synthetic MC4R-agonist peptide prevents ethanol-induced neuroinflammation, and if alcohol consumption produces changes in MC4R expression in the hippocampus and hypothalamus. Methods: Ethanol-preferring Sprague Dawley rats were selected offering access to 20% ethanol on alternate days for 4 weeks (intermittent access protocol). After this time, animals were i.p. administered an MC4R agonist peptide in the last 2 days of the protocol. Then, the expression of the proinflammatory cytokines interleukin 6 (IL-6), interleukin 1-beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) were measured in the hippocampus, hypothalamus and prefrontal cortex. It was also evaluated if ethanol intake produces alterations in the expression of MC4R in the hippocampus and the hypothalamus. Results: Alcohol consumption increased the expression of MC4R in the hippocampus and the hypothalamus. The administration of the MC4R agonist reduced IL-6, IL-1β and TNF-α levels in hippocampus, hypothalamus and prefrontal cortex, to those observed in control rats that did not drink alcohol. Conclusion: High ethanol consumption produces an increase in the expression of MC4R in the hippocampus and hypothalamus. The administration of a synthetic MC4R-agonist peptide prevents neuroinflammation induced by alcohol consumption in the hippocampus, hypothalamus, and prefrontal cortex. These results could explain the effect of α-MSH and other synthetic MC4R agonists in decreasing alcohol intake through the reduction of the ethanol-induced inflammatory response in the brain.

Magnetoencephalography and the Cortical Dynamics of Language Processing

2019 ◽  
pp. 114-153
Author(s):  
Riitta Salmelin ◽  
Jan Kujala ◽  
Mia Liljeström
Keyword(s):  
Language Processing ◽  
Language Disorders ◽  
Scientific Data ◽  
Neural Processing ◽  
Powerful Method ◽  
Cortical Dynamics ◽  
Brain Correlates ◽  
Adults And Children ◽  
The Brain ◽  
Selection Of

When seeking to uncover the brain correlates of language processing, timing and location are of the essence. Magnetoencephalography (MEG) offers them both, with the highest sensitivity to cortical activity. MEG has shown its worth in revealing cortical dynamics of reading, speech perception, and speech production in adults and children, in unimpaired language processing as well as developmental and acquired language disorders. The MEG signals, once recorded, provide an extensive selection of measures for examination of neural processing. Like all other neuroimaging tools, MEG has its own strengths and limitations of which the user should be aware in order to make the best possible use of this powerful method and to generate meaningful and reliable scientific data. This chapter reviews MEG methodology and how MEG has been used to study the cortical dynamics of language.

Sign in / Sign up

Export Citation Format

Share Document