scholarly journals Bad Timing for Epileptic Networks: Role of Temporal Dynamics in Seizures and Cognitive Deficits

2021 ◽  
pp. 153575972110018
Author(s):  
Pierre-Pascal Lenck-Santini
Keyword(s):  
Neuronal Activity ◽  
Cognitive Deficits ◽  
Brain Function ◽  
Temporal Dynamics ◽  
Cognitive Outcomes ◽  
Present Evidence ◽  
Dynamic Coordination ◽  
Epileptic Networks

The precise coordination of neuronal activity is critical for optimal brain function. When such coordination fails, this can lead to dire consequences. In this review, I will present evidence that in epilepsy, failed coordination leads not only to seizures but also to alterations of the rhythmical patterns observed in the electroencephalogram and cognitive deficits. Restoring the dynamic coordination of epileptic networks could therefore both improve seizures and cognitive outcomes.

scholarly journals Infectious disease-associated encephalopathies

Critical Care ◽  
2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Maria C. Barbosa-Silva ◽  
Maiara N. Lima ◽  
Denise Battaglini ◽  
Chiara Robba ◽  
Paolo Pelosi ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Cognitive Deficits ◽  
Brain Function ◽  
Cell Activation ◽  
Therapeutic Strategies ◽  
Barrier Dysfunction ◽  
Glial Cell Activation ◽  
The Central Nervous System ◽  
Underlying Mechanisms

AbstractInfectious diseases may affect brain function and cause encephalopathy even when the pathogen does not directly infect the central nervous system, known as infectious disease-associated encephalopathy. The systemic inflammatory process may result in neuroinflammation, with glial cell activation and increased levels of cytokines, reduced neurotrophic factors, blood–brain barrier dysfunction, neurotransmitter metabolism imbalances, and neurotoxicity, and behavioral and cognitive impairments often occur in the late course. Even though infectious disease-associated encephalopathies may cause devastating neurologic and cognitive deficits, the concept of infectious disease-associated encephalopathies is still under-investigated; knowledge of the underlying mechanisms, which may be distinct from those of encephalopathies of non-infectious cause, is still limited. In this review, we focus on the pathophysiology of encephalopathies associated with peripheral (sepsis, malaria, influenza, and COVID-19), emerging therapeutic strategies, and the role of neuroinflammation. Graphic abstract

scholarly journals Neuronal pattern separation of motion-relevant input in LIP activity

2017 ◽  
Vol 117 (2) ◽  
pp. 738-755 ◽  
Author(s):  
Nareg Berberian ◽  
Amanda MacPherson ◽  
Eloïse Giraud ◽  
Lydia Richardson ◽  
J.-P. Thivierge
Keyword(s):  
Neuronal Activity ◽  
Neural Activity ◽  
Population Model ◽  
Visual Motion ◽  
Temporal Dynamics ◽  
Strong Predictor ◽  
Pattern Separation ◽  
Sensory Stimuli ◽  
Sensory Discrimination

In various regions of the brain, neurons discriminate sensory stimuli by decreasing the similarity between ambiguous input patterns. Here, we examine whether this process of pattern separation may drive the rapid discrimination of visual motion stimuli in the lateral intraparietal area (LIP). Starting with a simple mean-rate population model that captures neuronal activity in LIP, we show that overlapping input patterns can be reformatted dynamically to give rise to separated patterns of neuronal activity. The population model predicts that a key ingredient of pattern separation is the presence of heterogeneity in the response of individual units. Furthermore, the model proposes that pattern separation relies on heterogeneity in the temporal dynamics of neural activity and not merely in the mean firing rates of individual neurons over time. We confirm these predictions in recordings of macaque LIP neurons and show that the accuracy of pattern separation is a strong predictor of behavioral performance. Overall, results propose that LIP relies on neuronal pattern separation to facilitate decision-relevant discrimination of sensory stimuli. NEW & NOTEWORTHY A new hypothesis is proposed on the role of the lateral intraparietal (LIP) region of cortex during rapid decision making. This hypothesis suggests that LIP alters the representation of ambiguous inputs to reduce their overlap, thus improving sensory discrimination. A combination of computational modeling, theoretical analysis, and electrophysiological data shows that the pattern separation hypothesis links neural activity to behavior and offers novel predictions on the role of LIP during sensory discrimination.

scholarly journals Role of Astrocytic Mitochondria in Limiting Ischemic Brain Injury?

Physiology ◽  
2018 ◽  
Vol 33 (2) ◽  
pp. 99-112 ◽  
Author(s):  
Evelyn K. Shih ◽  
Michael B. Robinson
Keyword(s):  
Brain Injury ◽  
Neuronal Activity ◽  
Brain Function ◽  
Functional Significance ◽  
Normal Brain ◽  
Ischemic Brain Injury ◽  
Ischemic Brain ◽  
Normal Brain Function

Until recently, astrocyte processes were thought to be too small to contain mitochondria. However, it is now clear that mitochondria are found throughout fine astrocyte processes and are mobile with neuronal activity resulting in positioning near synapses. In this review, we discuss evidence that astrocytic mitochondria confer selective resiliency to astrocytes during ischemic insults and the functional significance of these mitochondria for normal brain function.

Anesthesiology: Resetting Our Sights on Long-term Outcomes: The 2020 John W. Severinghaus Lecture on Translational Science

2021 ◽  
Author(s):  
Beverley A. Orser
Keyword(s):  
Cognitive Deficits ◽  
Brain Function ◽  
Animal Studies ◽  
Adverse Outcomes ◽  
Cognitive Outcomes ◽  
Long Term Outcomes ◽  
Anesthetic Drugs ◽  
Patients Experience ◽  
New Strategies

Anesthesiologists have worked relentlessly to improve intraoperative anesthesia care. They are now well positioned to expand their horizons and address many of the longer-term adverse consequences of anesthesia and surgery. Perioperative neurocognitive disorders, chronic postoperative pain, and opioid misuse are not inevitable adverse outcomes; rather, they are preventable and treatable conditions that deserve attention. The author’s research team has investigated why patients experience new cognitive deficits after anesthesia and surgery. Their animal studies have shown that anesthetic drugs trigger overactivity of “memory-blocking receptors” that persists after the drugs are eliminated, and they have discovered new strategies to preserve brain function by repurposing available drugs and developing novel therapeutics that inhibit these receptors. Clinical trials are in progress to examine the cognitive outcomes of such strategies. This work is just one example of how anesthesiologists are advancing science with the goal of improving the lives of patients.

scholarly journals Neuronal activity triggers uptake of hematopoietic extracellular vesicles in vivo

2019 ◽  
Author(s):  
Ivan-Maximiliano Kur ◽  
Pierre-Hugues Prouvot ◽  
Ting Fu ◽  
Wei Fan ◽  
Felicia Müller-Braun ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Neuronal Activity ◽  
Brain Function ◽  
Neural Transmission ◽  
Health And Disease ◽  
Vital Component ◽  
Peripheral Immune Cells ◽  
The Brain

AbstractCommunication with the hematopoietic system is a vital component of regulating brain function in health and disease. Traditionally, the major routes considered for this neuroimmune communication are either by individual molecules such as cytokines carried by blood, by neural transmission, or in more severe pathologies, by entry of peripheral immune cells into the brain. In addition, functional mRNA from peripheral blood can be directly transferred to neurons via extracellular vesicles (EVs) but the parameters that determine their uptake are unknown. We show that transfer of EVs from blood is triggered by neuronal activity in vivo. Importantly, this transfer occurs not only in pathological stimulation but also by neuronal activation caused by the physiological stimulus of novel object recognition. This discovery suggests a continuous role of EVs under pathological conditions as well as during routine cognitive tasks in the healthy brain.

Improving the questions we ask, with Psychology and Cognitive Conflict.

2018 ◽  
Author(s):  
Brett Buttliere
Keyword(s):  
Problem Solving ◽  
Scientific Method ◽  
Meaning Making ◽  
Cognitive Conflict ◽  
Empirical Literature ◽  
Present Evidence ◽  
Scientific Papers ◽  
Science In Society

Over the last decade, there have been many suggestions to improve how scientists answer their questions, but far fewer attempt to improve the questions scientists are asking in the first place. The goal of the paper is then to examine and summarize synthesize the evidence on how to ask the best questions possible. First is a brief review of the philosophical and empirical literature on how the best science is done, which implicitly but not explicitly mentions the role of psychology and especially cognitive conflict. Then we more closely focus on the psychology of the scientist, finding that they are humans, engaged in a meaning making process, and that cognitive conflict is a necessary input for any learning or change in the system. The scientific method is, of course, a specialized meaning making process. We present evidence for this central role of cognitive conflict in science by examining the most discussed scientific papers between 2013 and 2017, which are, in general, controversial and about big problems (e.g., whether vaccines cause autism, how often doctors kill us with their mistakes). Toward the end we discuss the role of science in society, suggesting science itself is an uncertainty reducing and problem solving enterprise. From this basis we encourage scientists to take riskier stances on bigger topics, for the good of themselves and society generally.

Microbiota-Immune System Interactions in Human Neurological Disorders

2020 ◽  
Vol 19 (7) ◽  
pp. 509-526
Author(s):  
Qin Huang ◽  
Fang Yu ◽  
Di Liao ◽  
Jian Xia
Keyword(s):  
Immune System ◽  
Gut Microbiota ◽  
Neurological Disorders ◽  
Brain Function ◽  
Neurological Diseases ◽  
Host Immune System ◽  
Gut Dysbiosis ◽  
Characteristic Features ◽  
Novel Therapeutic Strategies

: Recent studies implicate microbiota-brain communication as an essential factor for physiology and pathophysiology in brain function and neurodevelopment. One of the pivotal mechanisms about gut to brain communication is through the regulation and interaction of gut microbiota on the host immune system. In this review, we will discuss the role of microbiota-immune systeminteractions in human neurological disorders. The characteristic features in the development of neurological diseases include gut dysbiosis, the disturbed intestinal/Blood-Brain Barrier (BBB) permeability, the activated inflammatory response, and the changed microbial metabolites. Neurological disorders contribute to gut dysbiosis and some relevant metabolites in a top-down way. In turn, the activated immune system induced by the change of gut microbiota may deteriorate the development of neurological diseases through the disturbed gut/BBB barrier in a down-top way. Understanding the characterization and identification of microbiome-immune- brain signaling pathways will help us to yield novel therapeutic strategies by targeting the gut microbiome in neurological disease.

scholarly journals Corticostriatal control of defense behavior in mice induced by auditory looming cues

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhong Li ◽  
Jin-Xing Wei ◽  
Guang-Wei Zhang ◽  
Junxiang J. Huang ◽  
Brian Zingg ◽  
...  
Keyword(s):  
Essential Role ◽  
Neural Circuits ◽  
Temporal Dynamics ◽  
Defense Behavior ◽  
Innate Defense ◽  
Sensory Inputs ◽  
Corticostriatal Projections ◽  
Behavioral Transition ◽  
Auditory Looming

AbstractAnimals exhibit innate defense behaviors in response to approaching threats cued by the dynamics of sensory inputs of various modalities. The underlying neural circuits have been mostly studied in the visual system, but remain unclear for other modalities. Here, by utilizing sounds with increasing (vs. decreasing) loudness to mimic looming (vs. receding) objects, we find that looming sounds elicit stereotypical sequential defensive reactions: freezing followed by flight. Both behaviors require the activity of auditory cortex, in particular the sustained type of responses, but are differentially mediated by corticostriatal projections primarily innervating D2 neurons in the tail of the striatum and corticocollicular projections to the superior colliculus, respectively. The behavioral transition from freezing to flight can be attributed to the differential temporal dynamics of the striatal and collicular neurons in their responses to looming sound stimuli. Our results reveal an essential role of the striatum in the innate defense control.

scholarly journals Recent Advancements in the Mechanisms Underlying Resistance to PD-1/PD-L1 Blockade Immunotherapy

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 663
Author(s):  
Yu Yuan ◽  
Abdalla Adam ◽  
Chen Zhao ◽  
Honglei Chen
Keyword(s):  
Immune Evasion ◽  
Immune Checkpoint ◽  
Poor Prognosis ◽  
Target Therapy ◽  
Acquired Resistance ◽  
Immune Checkpoint Blockade ◽  
Therapeutic Strategies ◽  
Present Evidence ◽  
Immunosuppressive Factor

Release of immunoreactive negative regulatory factors such as immune checkpoint limits antitumor responses. PD-L1 as a significant immunosuppressive factor has been involved in resistance to therapies such as chemotherapy and target therapy in various cancers. Via interacting with PD-1, PD-L1 can regulate other factors or lead to immune evasion of cancer cells. Besides, immune checkpoint blockade targeting PD-1/PD-L1 has promising therapeutic efficacy in the different tumors, but a significant percentage of patients cannot benefit from this therapy due to primary and acquired resistance during treatment. In this review, we described the utility of PD-L1 expression levels for predicting poor prognosis in some tumors and present evidence for a role of PD-L1 in resistance to therapies through PD-1/PD-L1 pathway and other correlating signaling pathways. Afterwards, we elaborate the key mechanisms underlying resistance to PD-1/PD-L1 blockade in cancer immunotherapy. Furthermore, promising combination of therapeutic strategies for patients resistant to PD-1/PD-L1 blockade therapy or other therapies associated with PD-L1 expression was also summarized.

scholarly journals Creatine Supplementation and Brain Health

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 586 ◽  
Author(s):  
Hamilton Roschel ◽  
Bruno Gualano ◽  
Sergej M. Ostojic ◽  
Eric S. Rawson
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Cognitive Function ◽  
Cognitive Processing ◽  
Brain Function ◽  
Creatine Supplementation ◽  
Short Review ◽  
Future Research ◽  
Brain Health

There is a robust and compelling body of evidence supporting the ergogenic and therapeutic role of creatine supplementation in muscle. Beyond these well-described effects and mechanisms, there is literature to suggest that creatine may also be beneficial to brain health (e.g., cognitive processing, brain function, and recovery from trauma). This is a growing field of research, and the purpose of this short review is to provide an update on the effects of creatine supplementation on brain health in humans. There is a potential for creatine supplementation to improve cognitive processing, especially in conditions characterized by brain creatine deficits, which could be induced by acute stressors (e.g., exercise, sleep deprivation) or chronic, pathologic conditions (e.g., creatine synthesis enzyme deficiencies, mild traumatic brain injury, aging, Alzheimer’s disease, depression). Despite this, the optimal creatine protocol able to increase brain creatine levels is still to be determined. Similarly, supplementation studies concomitantly assessing brain creatine and cognitive function are needed. Collectively, data available are promising and future research in the area is warranted.

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