INS Topical Seminar – Adrien Meguerditchian (LPC, Marseille)

From Thursday 6th April 2017 at 14:00
To Thursday 6th April 2017 at 15:30

Location : New INS Seminar Room, La Timone, Faculty of Medicine, 5th floor, red wing Marseille

 

"On the gestural origins of language: Communication in primates & hemispheric specialization of the brain."

Given the phylogenetical proximity between human and nonhuman primates, research on the communicative, motor and cognitive systems of our primate cousins could help us determining the prerequisites of some language properties inherited from our common ancestor. Whereas some researchers have suggested that language resulted from the evolution of the vocal system, this theory is now challenged by a growing number of authors supporting the “gestural origins” view. Such an alternative theory underlies the fundamental role of gestural communication in the first phylogenetic roots of language.

Such a gestural theory finds support in the considerable evidence of tight links between language organization in humans and gestures including co-speech gestures, sign language in deaf people, and preverbal pointing gestures in infants. Moreover, research has reported potential continuities between the communicative gestural system in nonhuman primates, its lateralization and several fundamental properties of language, such as intentionality, learning flexibility, referential properties and left-hemispheric specialization of the brain. In the present communication, I will review our previous and on-going works on the gestural and vocal behaviors in nonhuman primates, laterality as well as recent findings in anatomical brain imaging in chimpanzees and baboons. I will try to demonstrate that these data in ethology, comparative psychology and neurosciences speak not only for a specific significance of communicative gestures in the course of the language evolution and its hemispheric brain specialization but also for the "bimodal" origin of language with the progressive integration of the oro-facial and vocal control into the gestural intentional system.

 

For any question, feel free to contact:
Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (bnmorillon@gmail.com)

 



INS/Epinext Topical Seminar – Marta Favali (Paris)

From Friday 17th March 2017 at 11:00
To Friday 17th March 2017 at 12:30

Location : New INS Seminar Room, La Timone, Faculty of Medicine, 5th floor (red wing), Marseille

"Formal models of visual perception based on cortical architectures"

I will show the integration of geometric models of visual perception with dimensionality reduction techniques. Starting from the model of association fields introduced by Citti and Sarti [2], which gives a justification of perceptual completion based on the functionality of the primary visual cortex (V1), it is possible to model the cellular connectivity by solving systems of stochastic differential equations as described in [9] and [1], obtaining the probability density that is the probability of connection between simple cells in V1 [1]. Starting from these kernels, the problem of grouping is faced by means of spectral analysis of suitable affinity matrices [2,7]. For the numerical simulations, I have consider particularly Kanizsa figures as clear examples of problems of visual perception [5], and retinal images, to afford problems of grouping during the tracking of blood vessels [4]. Finally I will show a comparison between the results obtained through these models with functional data fMRI, in order to afford the problem of identification and reconstruction of images from fMRI activity [3,6,8].

References
[1] D. Barbieri, G. Citti, G. Cocci, A. Sarti, A cortical-inspired geometry for contour perception., 2013.
[2] G. Citti and A. Sarti, A cortical based model of perceptual completion in the roto-translation space., Journal of Mathematical Imaging and Vision, 24(3):307-326, 2006.
[3] K. N. Kay, T. Naselaris, R. J. Prenger, and J. L. Gallant. Identifying natural images from human brain activity. Nature, 452(7185): 352-355, 2008.
[4] M. Favali, S. Abbasi-Sureshjani, B. H. Romeny, and A. Sarti. Analysis of vessel connectivities in retinal images by cortically inspired spectral clustering. Journal of Mathematical Imaging and Vision, 56(1):158-172, 2016a.
[5] M. Favali, G. Citti, A. Sarti, Local and global gestalt laws: A neurally based spectral approach, Neural Computation, February 2017, Vol. 29, No. 2, Pages: 394-422.
[6] T. Naselaris, R. J. Prenger, K. N Kay, M. Oliver, and J. L. Gallant. Bayesian reconstruction of natural images from human brain activity. Neuron, 63(6):902-915, 2009.
[7] A. Sarti, G. Citti, The constitution of visual perceptual units in the functional architecture of V1, Journal of computational neuroscience, 38(2):285–300, 2015.
[8] B.Thirion, E. Duchesnay, E. Hubbard, J. Dubois, J. Poline, D. Lebihan, and S. Dehaene. Inverse retinotopy: inferring the visual content of images from brain activation patterns. Neuroimage, 33(4):1104-1116, 2006.
[9] L.R. Williams, D.W. Jacobs, Stochastic completion fields., ICCV Proceedings, 1995.

For any question, feel free to contact:
Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (bnmorillon@gmail.com)



INS Keynote Seminar – Sylvain Baillet (Montreal)

From Thursday 2nd March 2017 at 14:00
To Thursday 2nd March 2017 at 15:30

Location : New INS Seminar Room, La Timone, Faculty of Medicine, 5th floor (red wing), Marseille

"Possible mechanisms underlying the polyrhythmic activity of the brain: from rest to perception."

One broad objective in neuroscience is to comprehend the mechanisms of large-scale, oscillatory neural dynamics: how they enable functions by shaping communication in brain networks, and how the earliest detection of their alterations in disease can contribute to improved healthcare prevention and interventions. To contribute toward this goal, our approach is to combine imaging methods and experimental neuroscience with computational and disease models, neuromodulation techniques, and translational arms to the clinic and industry. Our rationale is that the ubiquitous polyrhythmic activity of the brain has been approached empirically, with underlying mechanisms that remain not understood.
This hinders our comprehension of how 1) perception and behaviour emerge from brain network activity, and 2) the pathophysiological developments of brain and mental-health disorders increasingly studied as network diseases, affect large-scale neural communication.

These difficult questions require a bottom-up approach: We aim to understand how basic physiological factors of neural integrity and function shape the dynamical structure of oscillatory brain rhythms, such as their interdependence across multiple frequencies through cross-frequency coupling. These phenomena represent a deep source of uncharted markers of neural excitability, activity and connectivity. I will illustrate these principles with our latest results concerning the resting brain, multimodal perception and pathophysiological markers of epilepsy and neurodegenerative syndromes.

For any question, feel free to contact:
Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (bnmorillon@gmail.com)



INS Keynote Seminar – Valentin Wyart (Paris)

From Thursday 23rd February 2017 at 14:00
To Thursday 23rd February 2017 at 15:30

Location : New INS Seminar Room, La Timone, Faculty of Medicine, 5th floor (red wing), Marseille

"Premature, self-confirmatory commitment to uncertain decisions during pharmacologically induced transition to psychosis: a placebo-controlled, double-blind EEG study in healthy human subjects"

In schizophrenia, early stages of psychosis are characterized by a state of pathological uncertainty (or 'strangeness') which is difficult to study in patients due to its transitional nature. Therefore, the alterations of mental processes which lead to full-blown delusions remain largely unknown. Here we studied a pharmacological model of this condition using ketamine, an NMDA receptor antagonist, in healthy subjects performing a decision-making task based on ambiguous probabilistic cues.
Computational modeling of subjects' behavior under ketamine revealed a decrease in the precision of inference - the mental process of interpreting and accumulating evidence during decision-making. The analysis of simultaneously recorded EEG signals provided support for this selective alteration, by showing a degraded neural coding of the evidence provided by individual cues. Furthermore, upcoming decisions could be decoded earlier from EEG signals under ketamine, and evidence inconsistent with upcoming decisions were down-weighted in the inference process.
Together, these findings indicate a premature, self-confirmatory commitment to uncertain decisions under ketamine, a selective alteration of decision-making which could explain the stabilization of aberrant beliefs characteristic of psychosis.

For any question, feel free to contact:
Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (bnmorillon@gmail.com)



Morning’s meeting: public information and sharing on epilepsy

From Saturday 4th February 2017 at 09:00
To Saturday 4th February 2017 at 12:00

Location : Hôpital de la Timone - Amphithéâtre HA1 264 Rue Saint Pierre Marseille

Le service de Neurophysiologie Clinique dirigé par le Prof. Fabrice Bartolomei organise une matinée d'information et d’échanges sur l’épilepsie prévue le 04/02/2017 à l'Amphi HA1 de l'Hôpital Timone. L’organisation de cette réunion compte avec le soutien d’Epilepsie France (www.epilepsie-france.com) et de la FHU Epinext (www.epinext.org) et est sponsorisé par le laboratoire UCB.

Il s'agit d'une réunion grand public dédiée surtout aux patients et leurs familles où on présentera les réseaux de soins en épileptologie, c’est qu’une crise d’épilepsie, quels sont les progrès qui ont été fait en génétique, comment on développe un médicament antiépileptique et une discussion autour des conflits d’intérêts. Cette matinée est ouverte aussi au personnel du corps médical ou des chercheurs qui pourraient être intéressés par l’épilepsie.

Vous trouverez ci-dessous le programme et le plan d’accès à la Faculté de Médecine Timone.

PROGRAMME

ITINÉRAIRE

L’inscription est gratuite mais obligatoire jusqu’au 31/01/2017 sur ce site :  https://fr.surveymonkey.com/r/9VTWRG2



INS Keynote Seminar – Maria SANCHEZ-VIVES (Barcelona)

From Thursday 2nd February 2017 at 14:00
To Thursday 2nd February 2017 at 16:00

Location : New INS Seminar Room, La Timone, Faculty of Medicine, 5th floor, red wing Marseille

Abstract: "Slow oscillations dominate the activity of both the intact and the isolated cerebral cortex and present similar characteristics across different cortical areas. These properties led to the suggestion that slow oscillations are the default emergent activity of the cortical network (1). Such default activity is a low complexity state that integrates neuronal membrane, synaptic activity and connectivity properties of the cortex. It provides a gauge of the state of the underlying network, being sensitive to variations of parameters such as ionic levels (2), temperature (3) or excitatory/inhibitory balance (4). It also serves the identification of pathological changes, having been used to characterize transgenic models of neurological diseases (5).

This cortical default activity is shaped and it acts as a powerful attractor leading to a breakdown of cortical connectivity and complexity. Getting out of this attractor is necessary for the brain to recover the levels of complexity associated with conscious states.

1. Sanchez-Vives, & Mattia (2014). Slow wave activity as the default mode of the cerebral cortex. Arch Ital Biol, 152, 147

2. Sancristóbal et al (2016). Collective stochastic coherence in recurrent neuronal networks. Nature Physics, 12(9), 881

3. Reiget et al (2010). Temperature modulation of slow and fast cortical rhythms. Journal of neurophysiology, 103(3), 1253

4. Sanchez-Vives et al. (2010). Inhibitory modulation of cortical up states. Journal of neurophysiology, 104(3), 1314

5. Ruiz-Mejias, et al. "Overexpression of Dyrk1A, a down syndrome candidate, decreases excitability and impairs gamma oscillations in the prefrontal cortex." Journal of Neuroscience 36.13 (2016): 3648.



INS Keynote Seminar – Bruno CAULI (Paris)

From Thursday 12th January 2017 at 14:00
To Thursday 12th January 2017 at 15:30

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

"Neurogenic control of neurovascular coupling".

The cerebral cortex comprises diverse areas involved in perception, movement or cognition. In spite of this functional diversity, the cortical network is formed with the repetition of a microcircuit containing excitatory and inhibitory neuronal types. The activity of this microcircuit, its local cerebral blood flow and metabolism are tightly coupled to match the increased energy needs occurring during neuronal processing. This neurovascular and neurometabolic coupling, essential to normal brain function and integrity, is also the physiological basis of the hemodynamic contrasts widely used to map neuronal activity in health and disease.

Despite this physiopathological importance, the cellular and molecular mechanisms of neurovascular coupling remain poorly understood. Presumably because of the large diversity that characterizes cortical neurons (Ascoli et al., 2008, DeFelipe et al., 2013), the contribution of neuronally-driven mechanisms of neurovascular coupling has been largely overlooked. A major goal of our group is to understand how the microcircuit controls its own energy supply via interactions with the glio-vascular network. Using ex vivo and in vivo approaches our team pioneered the differential contribution of neuronal types in neurovascular coupling by showing that peculiar subsets of cortical neurons control the microvasculature (Cauli et al., 2004; Rancillac et al., 2006; Lecrux et al., 2011; Lacroix et al., 2015). These findings indicate that neurovascular coupling is achieved by specialized cell types. They also suggest that the hemodynamic contrasts visualized by modern imaging techniques only reflect the recruitment of these cells types. 

For any question, feel free to contact: 

Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (bnmorillon@gmail.com)



INS Keynote Seminar – Francesca SARGOLINI (Marseille)

From Thursday 1st December 2016 at 14:00
To Thursday 1st December 2016 at 16:00

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

"Entorhinal cortex and spatial navigation".

The ability to find our way in space relies on specialized cell populations, whose activity collectively provide a dynamic representation of self-localisation relative to external landmarks and goals. This cell network includes place cells in the hippocampus, head-direction cells in different cortical and subcortical areas, grid cells in the entorhinal cortex, and border/boundary cells in the parahippocampal areas. It is presently unknown which is the nature of the representation provided by each cell type and how they interact to support spatial navigation. For example, grid cells are spatially selective neurons whose firing fields form a regular hexagonal pattern that is relatively invariant across different environments. This periodic organization has inspired a number of models and theories suggesting a primary role of this cell population in self-motion-based navigation. In accordance with this hypothesis, we have recently shown that lesions of the entorhinal cortex impairs rats’ ability to estimate distances and directions on the bases on the information generated exclusively by their movements (i.e. in the absence of external landmarks). However, we have also shown that the metric properties of the grid cell map strongly rely on the external environment. In particular, changing the environment from 2D to 1D provokes drastic modifications of the map, whereas the activity from other place-selective cells (head-direction cells and border cells) is unmodified. These results demonstrate that the external information (and not only the self-motion cues) are primordial to establish the grid cell spatial activity, thus questioning their selective role in self-motion-based navigation.

For any question, feel free to contact: 

Demian Battaglia (demian.battaglia@univ-amu.fr) or Benjamin Morillon (benjamin.morillon@unvi-amu.fr)



“Musique, Language et surdité” (in French)

From Friday 25th November 2016 at 9:30
To Friday 25th November 2016 at 17:00

Location : Campus La Timone Lieux multiples à préciser Marseille

"Musique, language et surdité", ou "Quand les Neurosciences et la Clinique s'entendent".

Lors de cette journée réunissant des chercheurs en neurosciences, des professionnels de la surdité et des musiciens nous allons aborder les mécanismes et processus sous-jacents mis en  oeuvre lors du traitement de la musique et expliquer les possibles effets de transfert à plusieurs niveaux du traitement du langage. Nous allons en suite faire un état de lieu des recherches qui ont été conduites sur la thématique surdité, language et musique ainsi qu'exposer de manière concrète des interventions musicales menées auprès d'enfants malentendants et développer de possibles perspectives de réeducation et de recherche.

Inscription gratuite mais obligatoire (nombre de places limité) avant le vendredi 18 Novembre. Cliquer ici.

Téléchargez le programme.

LanguageSurditéMusique



INS Keynote Seminar – Sylvie NOZARADAN (Sidney)

From Thursday 13th October 2016 at 14:00
To Thursday 13th October 2016 at 15:30

Location : INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

"How musical rhythm entrains the human brain activity,

revealed with surface and intra-cerebral EEG frequency-tagging".

 

Getting entrained to music is a common activity shared by all human cultures. In my research, I investigate the relationship between musical rhythm, as a powerful non-verbal means of inter-personal communication, and the rhythmic activity of the human brain. To this end, my colleagues and I developed an original frequency-tagging approach to capture the neural encoding of musical rhythms with surface or intracerebral EEG.

I will present experiments conducted in healthy and brain-damaged adults, in infants and in non-human animals while exposed to rhythms. Results show that, although the auditory system presents a remarkable ability to synchronize to the rhythmic input, the neural network responding to rhythms transforms the rhythmic input by boosting specific frequencies. We found that this selective shaping is correlated to the individual perception and entrainment to move on rhythms.

Short Bio: Sylvie Nozaradan (http://sylvienozaradan.webnode.com//), MD PhD, is currently an ARC Discovery Early Career Researcher at the MARCS Institute, Western Sydney University, where she joined in 2016 the Music Cognition and Action group headed by Prof Peter Keller. Previously, she was a post-doctoral research fellow at the Institute of Neuroscience, UCL (Belgium). She received a double PhD in neuroscience from UCL and the BRAMS, Montreal (Canada), for her work on the neural entrainment to musical rhythm. She has a double background in music (master in Music performance and music writing, CrB, Belgium) and science (medical doctor degree, UCL).

 

For any question, feel free to contact: 

Daniele Schon (daniele.schon@univ-amu.fr) or Demian Battaglia (demian.battaglia@univ-amu.fr)



SFR “Cerveau et Cognition” day – Giulio TONONI (Madison, Wisconsin)

From Friday 8th July 2016 at 10:30
To Friday 8th July 2016 at 18:00

Location : Salle de Conférence Maurice Toga, La Timone, Faculty of medecine, Entrance hall, on the left side (1st floor), Marseille

Keynote lecture (from 10.30 to 11:30):

"Consciousness: From Theory to Practice".

Neuroscience has made great progress in relating the behavioral and neural correlates of consciousness. Yet it has proven hard to establish which neural structures and modes of activity are necessary and sufficient for being conscious. Moreover, empirical studies are inadequate to assess the presence and quality of consciousness in difficult cases, such as certain unresponsive patients, newborn infants, animals with behaviors and brains unlike ours, or machines that approximate our cognitive abilities. To make headway, empirical studies must be complemented by a fundamental theory of what consciousness is and what it takes to have it. Integrated information theory (IIT) starts from the essential properties of consciousness and translates them into requirements that any physical system must satisfy to be conscious. It goes on to show that the physical substrate of consciousness (PSC) must be a maximum of intrinsic, irreducible cause-effect power, and provides a calculus to determine, in principle, both the quality and the quantity of an experience. Applied to the brain, the principles of IIT imply that the PSC is constituted of those neural elements that together compose a maximum of intrinsic cause-effect power, and that such maximum can shrink, move, split and disintegrate depending on various anatomical and physiological parameters. Similarly, IIT predicts that the spatial grain of the neural elements constituting the PSC, the temporal grain at which they do so, and the relevant neural states, are again those that maximize intrinsic cause-effect power. These predictions are in principle testable with stimulation and recording experiments at the systems and cellular levels. The theory can explain parsimoniously many known facts about the relationship between consciousness and the brain, including its association with certain cortical structures, its breakdown in deep sleep, anesthesia and seizures, and its return in dreams. Finally, the theory has motivated the development of promising new tests for the practical assessment of consciousness in non-communicative subjects. 

 

The main lecture will be followed by a tutorial on:

Integrated Information Theory (IIT), with an open discussion on the nature of consciousness 

14:00: Overview of the tutorial

14:05: Axioms and postulates of IIT

  • Intrinsic existence, Composition, Information, Integration, Exclusion

  • An experience as a conceptual structure

14:40:
  • Explanatory, predictive, and inferential power of IIT

  • Integrated information – a practical approach

  • Sleep, Anesthesia, Disorders of consciousness

15:20-15:30: break

15:30: Consciousness in nature and in artificial systems

  •  Macro and micro

  • Consciousness in animals and in machines: a difficult call

  • A double dissociation between consciousness and intelligence

  • If consciousness is integrated information, is consciousness everywhere? 

  • Why did consciousness evolve? Insights from evolving animats

  • Open issues and future developments

16:10-17:00
  • Integrated information and Shannon information

  • Consciousness, meaning, and matching

  • Concluding remarks 



INS Topical Seminar – Eyal BERGMANN (Technion, Haifa)

From Thursday 30th June 2016 at 14:00
To Thursday 30th June 2016 at 16:00

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title:

"Spatially-localized Coupling of Mouse but not Human Sensory and Memory Networks 

revealed by Intrinsic Functional Connectivity".

Webcard_Bergmann

 

While the hippocampal memory system has been relatively conserved across mammals, the cerebral cortex underwent massive expansion and elaboration. A central question in brain evolution is how cortical development affected the nature of sensory inputs to the hippocampus. To address this question, we compared cortico-hippocampal connectivity using intrinsic functional connectivity MRI (fcMRI) in awake mice and humans. We found that fcMRI recapitulates anatomical connectivity patterns, demonstrating sensory mapping within the mouse parahippocampal region. Moreover, we identified a similar topographical modality-specific organization along the longitudinal axis of the mouse hippocampus, indicating that sensory information arriving to the hippocampus is only partly integrated. Finally, comparing cortico-hippocampal connectivity across species, we discovered preferential hippocampal connectivity of sensory cortical networks in mice, in contrast to preferential connectivity of association cortical networks in humans. Supporting this observation, in humans but not mice, sensory and association cortical networks are connected to spatially distinct subregions in the parahippocampal region. Collectively, these findings indicate that sensory cortical networks are coupled to the mouse, but not human, hippocampal memory system, suggesting that the emergence of expanded and new association areas in humans resulted in rerouting of cortical information flow and dissociation of primary sensory information from the hippocampus.  

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Christophe Bernard (cristophe Bernard@univ-amu.fr)


Joint INS/INT Keynote seminar – Charles GRAY (Bozeman, MT)

From Friday 17th June 2016 at 14:30
To Friday 17th June 2016 at 15:30

Location : salle gastaut at INT, La Timone, INT building, ground floor, Marseille

Title:

"Distributed Cortico-cortical Interactions Underlying Visual Working Memory"

GRAY_WebCard

Abstract: 

Cognitive processes, such as working memory, engage large neuronal populations spanning widespread cortical and subcortical areas. To further understand the task dependence, and the spectral, temporal and spatial organization of these activity patterns, we designed a large-scale recording system that enables the chronic implanta- tion of 256 independently movable microelectrodes spanning an entire cerebral hemisphere in macaque monkeys. We implanted this system in two animals and recorded neuronal activity from more than 60 separate cortical areas while the animals performed an object-based, visual delayed match-to-sample task and a set of control tasks. Analysis of the unit activity revealed a widespread distribution of task dependent and content specific cellular responses, concentrated in multiple areas of the prefrontal, premotor, posterior parietal and visual cortices. Analysis of the local field potential (LFP) revealed striking regional variations in the distribution of spectral power and coherence. These signals displayed a mixture of increases and decreases in magnitude during the task. Coherence and phase-locking analyses revealed widespread, task-dependent patterns of correlated activity that varied in frequency and phase. These studies provide the first analysis of the temporal and spectral patterns of cortical neuronal activity spanning a cerebral hemisphere in macaque monkeys performing a cognitive task.

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Andrea Brovelli (andrea.brovelli@univ-amu.fr)


INS Keynote Seminar – Benjamin MORILLON (INS, Marseille)

From Thursday 19th May 2016 at 14:00
To Thursday 19th May 2016 at 15:30

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title:

"Motor Origin of Temporal Predictions in Auditory Attention"

WebCard_Morillon

Abstract: 


Temporal predictions are increasingly recognized as fundamental instruments for optimizing performance, allowing humans to exploit regularities in the world. It is proposed that the motor system instantiates predictive timing mechanisms, helping to synchronize temporal fluctuations of attention with the timing of events in a task-relevant stream, thus facilitating sensory selection. I will present a neurophysiological account for this theory in a paradigm where participants track a slow reference beat while extracting auditory target tones delivered on-beat and interleaved with distractors. At the behavioral level I will show that overt rhythmic movements sharpen the temporal selection of auditory stimuli, thereby improving performance. Capitalizing on magneto-encephalography recordings I will provide evidence that temporal predictions are reflected in Beta-band (~20Hz) energy fluctuations in the sensorimotor cortex. While auditory processing in both auditory and right frontal regions is modulated by temporal predictions, only energy fluctuations in the right frontal cortex predict behavioral outcome. Together, these findings are compatible with Active Sensing theories, which emphasize the prominent role of motor activity in sensory processing. 

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Daniele Schon (daniele.schon@univ-amu.fr)


INS Topical Seminar – May BROOKS-KAYAL (University of Colorado)

From Tuesday 17th May 2016 at 11:00
To Tuesday 17th May 2016 at 12:30

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title:

"BDNF and JAK/STAT regulation after brain injury: potential new targets for disease modification"

WebCard_BrooksKayal

 

Dr. Brooks-Kayal is the Chief and Ponzio Family Chair of Pediatric Neurology at Children's Hospital Colorado, Professor of Pediatrics and Neurology and Co-Director of the Translational Epilepsy Research Program at the University of Colorado School of Medicine. She is interested in the development of new treatments for epilepsy. Dr. Brooks-Kayal’s research focuses on understanding the molecular and cellular mechanisms that result in development of epilepsy in order to develop new ways to prevent and treat this disorder. Her lab has identified changes in inhibitory neurotransmission, specifically GABA(A) receptor subunit expression, that may play a critical role in epilepsy development. Most recently, they have identified molecular signaling pathways, including BDNF and the CREB and JaK/STAT pathways, that regulate these receptor changes and shown that modulating these pathways can prevent these changes and inhibit epilepsy development. Her lab also studies the effects of early-life seizure activity and seizure treatment on brain development.

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Christophe Bernard (cristophe Bernard@univ-amu.fr)


INS Topical Mini-seminars – Peter VAN MIERLO and Ana COITO (Geneva)

From Thursday 12th May 2016 at 14:00
To Thursday 12th May 2016 at 16:00

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Three mini-talks about Directed Functional Connectivity & other advanced tools for EEG analysis in epileptic patients

WebCard_VanMIERLO 

Peter Van Mierlo's two mini-talks:

1. Localization of the seizure onset zone using directed functional connectivity

During this talk I will explain the methodology to calculate time-varying directed functional connectivity from intracranial EEG and how we can use it to localize the seizure onset zone. In 8 patients we will localize the SOZ based on the functional connectivity pattern from ictal intracranial EEG recordings. Afterwards, I will show how we can extend the method to a high number of intracranial channels and which pre-processing steps mostly influence the result. At the end I will present the methodology to extract the functional connectivity pattern from scalp EEG and use it to localize the SOZ in 5 patients from high-density ictal EEG recordings.

2. Automatic spike detection and EEG Source Imaging to localize the irritative zone: a study in 46 patients

In this more clinically oriented talk, I will introduce epilog epilepsy. This is a pipeline that automatically processes EEG. Epileptic spikes and seizures are detected from the EEG and mapped in the brain in 3D using advanced patient specific EEG source imaging. I will show results of the retrospective study in 46 patients.

Ana Coito's mini-talk:

3. Directed Functional Connectivity in Temporal Lobe Epilepsy in interictal spikes and resting-state using high-density EEG

In the first part of the talk, I will present our results regarding the investigation of the time-varying behaviour of epileptic networks during interictal spikes in left and right Temporal Lobe Epilepsy (TLE) at a whole-brain scale using directed functional connectivity applied to EEG source signals.
Because interictal spikes are not always visible in the scalp EEG, it is important to understand whether patients with epilepsy show already abnormal connectivity patterns during resting-state (no pathological acitivity). Indeed, a better characterization of abnormal networks in the absence of spikes could have an important diagnostic and prognostic value. So, in the second part of the talk, I will present our results regarding the investigation of resting-state EEG-based directed functional connectivity in patients with left TLE, right TLE vs healthy controls.
I will then show you that this data-driven EEG-based directed connectivity approach during resting-state periods revealed the Default-Mode Network (normally studied with fMRI) and its directionality.
Simultaneous recordings of intracranial and scalp EEG offer a huge potential to understand the intracranial correlates of scalp EEG. I will show you some preliminary results concerning the study of time-varying directed functional connectivity during interictal spikes that are seen with both scalp and intracranial EEG.

 

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Christian Benar (christian.benar@univ-amu.fr)


INS Keynote seminar – Pau GOROSTIZA (Barcelona)

From Thursday 28th April 2016 at 14:00
To Thursday 28th April 2016 at 15:30

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title:

"Remote control of biological processes with light "

WebCard_GorostizaLanga

Abstract: 

Nanoscale structures can be fabricated by machining and etching techniques, using a "top-down" approach. However, great benefits for biology and technology would be obtained if the nanomachines existing in nature (proteins) could be remotely controlled. In this "bottom-up" approach, one can take advantage of the great variety of protein functions (from motors to catalytic enzymes) for technological applicatons. 

We are using a recently developed remote actuator that acts on an ion channel (the ionotropic glutamate receptor) and allows to open and close it with light. When glutamate binds to glutamate receptors they are activated, which results in the opening of a transmembrane pore. The optical switch consists of a chemical compound featuring a photoisomerizable azobenzene group flanked by a glutamate moiety at one end, and a maleimide at the other end for conjugation to the protein. Under visible light, the azobenzene is extended (trans) and keeps the glutamate away from its binding site. Under ultraviolet light, the azobenzene is bent (cis) which allows glutamate binding and receptor activation. Photoswitching is rapid and reversible, as can be observed with patch clamp, and allows to control the cell membrane potential and intracellular calcium with high accuracy. We are applying this optical switch to remotely control cell activity (e.g. neuronal firing, secretion processes), and to study the molecular mechanisms of glutamate receptor gating and desensitization.

If interested in meeting the speaker, please contact

Demian Battaglia (demian.battaglia@univ-amu.fr)
or Piotr Bregestovski (piotr.bregestovski@univ-amu.fr)


INS Keynote seminar – Antoni VALERO CABRE (ICM, Paris)

From Thursday 21st April 2016 at 14:00
To Thursday 21st April 2016 at 15:30

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title:

"Mastering the waves: Entrainment of behaviorally relevant oscillatory activity in the human brain with invasive and non-invasive stimulation"

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Abstract: Prior evidence in monkeys and humans supports a crucial role for rhythmic brain activity in cognitive function, but are cerebral oscillations simply correlated, or causally linked to specific aspects of human cognition? Furthermore, can oscillatory activity be entrained locally at by means of invasive and non-invasive stimulation methods, and may such manipulation result in frequency specific improvements of cognition? To address these crucial questions, our lab is currently testing the manipulation of brain activity by means of non-invasive (Transcranial Magnetic Stimulation, TMS in healthy human) and invasive (Intracortical Stimulation in implanted epilepsy patients) bursts. Surface EEG (sEEG) and intracerebral (iEEG) recordings performed along are used in parallel to characterize the ability to impose behaviorally relevant oscillatory activity in local and extended brain networks. We will present evidence in healthy humans (n=14), that the TMS manipulation of the right Frontal Eye Fields (FEF), a region of the dorsal attentional network with brief rhythmic (vs. random) bursts, induces increases of fronto-parietal synchrony and frequency specific improvements of conscious visual detection for contralateral targets. This work suggests a causal link between oscillatory activity in a specific cortical region and cognitive processes modulating perception and access to visual consciousness. We will also present data in treatment-resistant epilepsy patients implanted with depth electrodes (n=3), stimulated for clinical characterization purposes with electrical bursts (with embedded frequencies), suggesting local entrainment, with power increases around the input frequency, phase-locked to the stimulation patters. Those effects are dependent on stimulation intensity and the distance between the contact pairs involved in stimulation, and most importantly, they prove particularly relevant in areas subtending the highest level of synchronization with the stimulated site prior stimulation. On the basis of this evidence, we will discuss how the manipulation local synchrony may open new avenues to explore the causal role of brain synchrony in specific cognitive processes; we will also outline some ideas for future applications to restore impaired behaviors subtended by abnormal brain rhythmic activity.

 

Relevant publications

  1. Rastelli, F. Tallon-Baudry, C. Migliaccio, R.  Toba, M. Ducorps, A. Pradat-Diehl, P. Duret, C. Dubois, B. Valero-Cabré, A. Bartolomeo, P. Neural dynamics of neglected targets in patients with right hemisphere damage. Cortex 2013, 49(7):1989-96.
  2. Chanes L, Quentin R, Tallon-Baudry C, Valero-Cabré A. Causal frequency-specific contributions of frontal spatiotemporal patterns induced by non invasive neurostimulation to visual performance enhancements in humans. J Neurosci 2013, 33, 5000-5
  3. Quentin R, Chanes L, Vernet M, Valero-Cabré A. Fronto-parietal anatomical connections influence the modulation of conscious visual perception by high-beta frontal oscillatory activity. Cerebral Cortex 2015, 25(8):2095-101.
  4. Quentin, R., Elkin Frankston, S., Vernet, M., Toba, M.N., Bartolomeo, P., Chanes, L. & Valero-Cabré, A. Visual Contrast Sensitivity Improvement by Right Frontal High-Beta Activity Is Mediated by Contrast Gain Mechanisms and Influenced by Fronto-Parietal White Matter Microstructure. Cerebral Cortex 2015, Apr 21.pii: bhv060
  5. Chanes, L., Quentin, R., Valero-Cabré, A. (2015) Arrhythmic activity in the left frontal eye field facilitates conscious visual perception in humans. Cortex, 2015, 71:240-7
If interested in meeting the speaker, please contact
Demian Battaglia (demian.battaglia@univ-amu.fr)
or Mireille Bonnard (mireille.bonnard@univ-amu.fr)


INS Keynote seminar – Gustavo DECO (UPF, Barcelona)

From Friday 11th March 2016 at 14:00
To Friday 11th March 2016 at 16:00

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title: The dynamics of resting fluctuations in the healthy and pathological brain: metastability and its dynamical cortical core 

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Resting state networks have been very well spatially characterised but their temporal dynamics are less well studied. Some evidence suggests that spontaneous activity consists of rapid transitions between a few functional connectivity states over time but the underlying mechanisms are not understood. Here, we utilized whole-brain computational modelling with a general neural mass model based on the normal form of a Hopf bifurcation to demonstrate that the temporal dynamics of resting state fluctuations emerge at the edge of the transition between asynchronous to oscillatory behaviour. Further, empirical functional connectivity dynamics (FCD) was shown to strongly constrain the dynamical working point of the model, where, importantly, the whole brain was shown to be maximally metastable. Finally, optimization of the spectral characteristics of each local brain region revealed the dynamical cortical core of the human brain driving the activity of the rest of the whole brain, which could serve a potential future biomarker. Applications to Parkinson and Alzheimer Disesases will be considered. 

If interested in meeting the speaker, please contact
Demian Battaglia (demian.battaglia@univ-amu.fr)


INS topical seminar – Matteo DI VOLO (GNT-ENS, Paris)

From Wednesday 9th March 2016 at 14:30
To Wednesday 9th March 2016 at 16:00

Location : New INS seminar room, La Timone, Faculty of medecine, 5th floor (red wing), Marseille

Title: Dopaminergic neurons dynamics in the Ventral Tegmental Area
and a computational approach to alcohol effect

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Experimental data show that alcohol consumption produces an increase of dopamine (DA) release in Nucleus Accumbens (NAc) from dopaminergic neurons of the Ventral Tegmental Area (VTA). This brain circuitry is crucial for cognitive processing of reward and reinforcement learning, and hence has a significant role in addiction.

We  discuss a computational approach to the dynamics of both DA and GABA neurons in the VTA by the implementation of a simplified biophysical model, showing their interaction and the way Glutamatergic inputs influence the overall activity. The circuit model of the VTA  will be used to describe the mechanisms through which Ethanol produces  a bursting dynamics in Dopaminergic neurons and how Alcohol effects on different targets cooperate to increase the dopamine level in NAc.

 

For informations or to meet the speaker contact:

Alessandro Torcini, alesanndro.torcini@univ-amu.fr