Science and news
Funsy science and news
Congratulations to Matthieu!!!
Matthieu Aguilera, PhD student in the FunSy team just obtain the ticket for the finals of my these in 180 seconds (MT 180). This event will take place on June 8th in Rennes, France. Matthieu’s work shows that early alterations in brain dynamics might be used as an early biomarker of Alzheimer’s disease. Check it…
Two gamma bands? Or two gamma complex ensembles?
In our newest preprint on BioRxiv, in collaboration with Alessandro Torcini and Matteo di Volo, we revisit a classic theory about the existence of two different gamma rhythms in the hippocampus CA1. We first deconstruct this theory, showing its insufficiency to account for the haphazard diversity of hippocampal gamma. We however reconstruct and rescue the…
Densely tied in space… but also for a sufficient time!
Functional interactions between brain regions or neurons have been described using features defined in network theory. For instance, the rich club phenomenon correspond to having high-degree nodes connected between them above chance-level. In our new Nature Physics paper we generalize this notion to dynamic networks. Indeed, in order for a certain spatial pattern in network…
Graph-based features to capture the embodiment of adaptive behavior
The cerebellar cortex encodes sensorimotor adaptation during skilled locomotor behaviors, however the precise relationship between synaptic connectivity and behavior is unclear. In our recent Nature Communications paper (in collaboration with Philippe Isope’s group at INCI, Strasbourg), we studied synaptic connectivity between granule cells (GCs) and Purkinje cells (PCs) in murine acute cerebellar slices using photostimulation…
Toward virtual connectomes for data augmentation
Personalized information on anatomic connectivity (structural connectivity; SC) or coordinated resting state activation patterns (functional connectivity; FC) is a source of powerful neuromarkers to detect and track the development of neurodegenerative diseases. However, there are often “gaps” in the available information, with only SC (or FC) being known but not FC (or SC). In our…
Effects of localized brain stimulation depend on dynamical state
Stimulation can be used to alter brain activity and is a therapeutic option for certain neu- rological conditions. However, predicting the distributed effects of local perturbations is difficult. Previous studies show that responses to stimulation depend on anatomical (or structural) coupling. In addition to structure, in our PLoS Computational Biology paper (in collaboration with Danielle…
The speed and geometry of resting state dynamic Functional Connectivity
We are happy announcing that a diptych of publications on resting dynamic Functional Connectivity is finally out on NeuroImage! Functional Connectivity (FC) measured on resting state fMRI is dynamic and continually reconfiguring. However these variations are not necessarily very large and discrete state transitions are difficult (or questionable) to identify. Here we introduce a new…
Is human cortical connectome optimized for ignition?
The activity of the cortex in mammals constantly fluctuates in relation to cognitive tasks, but also during rest. The ability of brain regions to display ignition, a fast transition from low to high activity is central for the emergence of conscious perception and decision making. In our recently published paper in PLoS Computational Biology (in…
Computing hubs and states in the hippocampus?
In dominant views, a neuron becomes a functional hub because of its special position within a circuit. In our recently accepted paper on Science Advances, we find experimental evidence supporting a much more democratic view in which almost a majority of recorded single units could serve as hub at least for some time and for…
Communication through transient and stochastic coherence
Inter-regional oscillatory coherence has been proposed as a mechanism for modulating communication. However oscillations in vivo are transient and fluctuate in time, frequency and phase. In out Nature Neuroscience paper we show that, despite their irregular and stochastic-like properties, oscillatory burst can still subserve flexible and selective routing of information. To reach this conclusion we…
Gender bias in peer-review: numeric parity is not enough!
Peer review is the cornerstone of scholarly publishing and it is essential that peer reviewers are appointed on the basis of their expertise alone. However, it is difficult to check for any bias in the peer-review process because the identity of peer reviewers generally remains confidential. In our eLife paper, using public information about the…
AD before plaques
Alzheimer’s disease (AD) is a neurodegenerative pathology commonly characterized by a progressive and irreversible deterioration of cognitive functions, especially memory. Although the etiology of AD remains unknown, a consensus has emerged on the amyloid hypothesis, which posits that increased production of soluble amyloid b (Ab) peptide induces neuronal network dysfunctions and cognitive deficits. In our…
Attentional modulation of non-tuned tuning curves
Tuning curves are the functions that relate the responses of sensory neurons to various values within one continuous stimulus dimension (such as the orientation of a bar in the visual domain or the frequency of a tone in the auditory domain). They are commonly determined by fitting a bell-shaped curve to the measured responses. However,…
Theta-gamma coupling as “Eureka”?
Spatial reference memory in rodents represents a unique opportunity to study brain mechanisms responsible for encoding, storage and retrieval of a memory. Even though its reliance on hippocampal networks has long been established, the precise computations performed by different hippocampal subfields during spatial learning are still not clear. In our Cerebral Cortex paper, to study…
Beyond the frontiers of neural types (and monkey vocalizations !?!)
Beyond the frontiers of neuronal types Cortical neurons and, particularly, inhibitory interneurons display a large diversity of morphological, synaptic, electrophysiological, and molecular properties, as well as diverse embryonic origins. However, a broad variability is generally observed even among cells that are grouped into a same class. In our Frontiers in Neural Circuits article in collaboration…
Sampling the “dynome” leads to dynamic Functional Connectivity
Simulations of whole-brain mean-field computational models with realistic connectivity determined by tractography studies enable us to reproduce with accuracy aspects of average Functional Connectivity (FC) in the resting state. Most computational studies, however, did not address the prominent non-stationarity in resting state FC. In our NeuroImage paper, we show that this non-stationarity reveals a rich…
Connectivity from calcium imaging of cultures?
In collaboration with Isabelle Guyon (Paris), Jordi Soriano (Barcelona), Javier Orlandi (Calgary) and others, we organized a machine learning Challenge on the Kaggle platform to unravel the connectivity of neuronal networks (realistic simulations, in order to know the ground truth and benchmark algorithms). The provided data was solely based on fluorescence time series of spontaneous…
Broad-band gamma from highly synchronous activity?
Visual stimulation elicits neuronal responses in visual cortex. When the contrast of the used stimuli increases, the power of this induced activity is boosted over a broad frequency range (30–100 Hz), called the ‘‘gamma band.’’ However, previous models trying to explain contrast-related power enhancements using synchronous oscillations failed to reproduce the observed spectra because they…
Hippocampal theta without pacemakers
Hippocampal theta rhythm is crucial for spatial memory and is thought to be generated by extrinsic inputs. In our Nature Neuroscience paper, though, we show that, using a complete rat hippocampus in vitro, several intrinsic, atropine-resistant theta generators can be found directly in CA1. These oscillators were organized along the septotemporal axis and arose independently…
About us
The Functional System’s Dynamics team is an emergent team of the Laboratory for Cognitive and Adaptive Neuroscience (CNRS UMR 7364), within the Interdisciplinary Thematic Institute “NeuroStra” at University of Strasbourg, member of the trinational Neuroscience Upper Rhine network (NEUREX). The team was kickstarted thanks to the support of the University of Strasbourg Institute of Advanced Studies (USIAS).
How to find us
We are located within the building of the Faculty of Psychology, at the ground floor (LNCA wing, to the right, end of the corridor, entering from Rue Goethe side).
LNCA – 12 rue Goethe, F-67000 STRASBOURG
Tramway lines C/E/F – stop “Université” – Bus line 2 (~15 min from central station) – Strasbourg Entzheim airport at ~40 min, high speed train to Paris CDG and Frankfurt / Main international hubs.