Publications by authors named "Bernard Christophe"

Degeneracy is defined as multiple sets of solutions that can produce very similar system performance. Degeneracy is seen across phylogenetic scales, in all kinds of organisms. In neuroscience, degeneracy can be seen in the constellation of biophysical properties that produce a neuron's characteristic intrinsic properties and/or the constellation of mechanisms that determine circuit outputs or behavior.

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  • During a type of sleep called NREM sleep, the brain has special events called sharp-wave ripples (SWRs) that help turn short-term memories into long-term memories.
  • Scientists studied how these SWRs work with a part of the brain called the retrosplenial cortex and how they might help in organizing and saving memories.
  • They found that when SWRs happen, certain brain activities called "up-states" and sleep spindles occur together, suggesting that these activities help the brain share information and strengthen memories.
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  • * Mice underwent resting-state functional MRI (rs-fMRI) scans at different times during the light and dark cycles, with data analyzed using group independent component analysis (ICA) and linear mixed-effect models (LMEM) to assess the impact of sex and lighting conditions on brain activity.
  • * Findings revealed new resting-state networks (RSNs) linked to day/night cycles and highlighted sex differences in brain activation, especially in mature males, while also noting increased activity in the pineal gland
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Integration of information across heterogeneous sources creates added scientific value. Interoperability of data, tools and models is, however, difficult to accomplish across spatial and temporal scales. Here we introduce the toolbox Parallel Co-Simulation, which enables the interoperation of simulators operating at different scales.

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  • * The relationship between stress and epilepsy is supported by neurobiological mechanisms, such as HPA axis dysfunction and altered neuroplasticity, that link the two conditions.
  • * Future treatment approaches may involve collaboration between clinicians and scientists to develop personalized therapies, using data integration and advancements in machine learning and neuromodulation.
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  • * Each in vitro model has strengths and weaknesses, and combining different models can enhance their effectiveness in screening new ASMs.
  • * The review emphasizes the importance of integrating various in vitro and in vivo studies, utilizing tissues from chronically epileptic animals, and using human-derived materials to improve the relevance and predictive value of ASM testing.
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  • Cognitive deficits are a common comorbidity accompanying epilepsy, indicating that neural dynamics supporting cognitive functions are permanently changed rather than just affected by the occasional seizures.
  • The study investigates how information processing—specifically storage and sharing of information—is disrupted in the hippocampus and entorhinal cortex in rats with experimental epilepsy.
  • Findings suggest that the organization and timing of these cognitive functions in epilepsy are less ordered and more chaotic than in healthy controls, which may contribute to the widespread cognitive impairments seen in individuals with epilepsy.
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  • The study investigated the role of brain-derived neurotrophic factor (BDNF) in epilepsy, specifically looking at its potential as a biomarker for epilepsy severity and related psychiatric conditions.
  • It analyzed serum BDNF levels in epilepsy patients from four centers in France, while documenting various clinical characteristics and conducting psychiatric screenings.
  • The results showed no significant correlation between serum BDNF levels and epilepsy features or depression, but found that the presence of anti-seizure medications (ASM) was linked to increased BDNF, especially with valproate and perampanel.
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Neuropixels probes have become a crucial tool for high-density electrophysiological recordings. Although most research involving these probes is in acute preparations, some scientific inquiries require long-term recordings in freely moving animals. Recent reports have presented prosthesis designs for chronic recordings, but some of them do not allow for probe recovery, which is desirable given their cost.

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Sleep and wake are defined through physiological and behavioral criteria and can be typically separated into non-rapid eye movement (NREM) sleep stages N1, N2, and N3, rapid eye movement (REM) sleep, and wake. Sleep and wake states are not homogenous in time. Their properties vary during the night and day cycle.

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Biocompatible and plastic neural interface devices allow for minimally invasive recording of brain activity. Increasing electrode density in such devices is essential for high-resolution neural recordings. Superimposing conductive leads in devices can help multiply the number of recording sites while keeping probes width small and suitable for implantation.

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  • Epilepsy is a complex condition that benefits from diverse study methods, including theoretical and computational models.
  • The review highlights how dynamical system tools help analyze seizure characteristics and classify them based on their behaviors during onset and offset.
  • It emphasizes the potential of computational models for improving clinical practices and personalized medicine, while also considering the role of glial cells and questioning traditional views focused solely on neurons.
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How status epilepticus (SE) is generated and propagates in the brain is not known. As for seizures, a patient-specific approach is necessary, and the analysis should be performed at the whole brain level. Personalized brain models can be used to study seizure genesis and propagation at the whole brain scale in The Virtual Brain (TVB), using the Epileptor mathematical construct.

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  • - Stress can lead to depression, but individual vulnerability before stressful events plays a key role in how severely someone might be affected.
  • - Researchers studied rats' sleep patterns before and after a stress event (social defeat) to identify specific sleep stages linked to vulnerability to depression using electroencephalogram recordings.
  • - The study found early and late sleep biomarkers that can predict which rats are likely to become depressed, suggesting potential for developing treatments aimed at those at high risk of stress-induced depression.
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The objective of this study is to evaluate Grassmannian constellations combined with a spread spectrum multiple access scheme for underwater acoustic mobile multiple access communication systems. These communication systems enable the coordination of a fleet of Autonomous Underwater Vehicles (AUVs) from a surface or bottom control unit, e.g.

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Decades of research have advanced our understanding of the biophysical mechanisms underlying consciousness. However, an overarching framework bridging between models of consciousness and the large-scale organization of spontaneous brain activity is still missing. Based on the observation that spontaneous brain activity dynamically switches between epochs of segregation and large-scale integration of information, we hypothesize a brain-state dependence of conscious access, whereby the presence of either segregated or integrated states marks distinct modes of information processing.

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Individuals use the observation of a conspecific to learn new behaviors and skills in many species. Whether observational learning is affected in epilepsy is not known. Using the pilocarpine rat model of epilepsy, we assessed learning by observation in a spatial task.

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