Biology subjects

Rault, N.

Publications and source records attributed to Rault, N..

3 recordsLinked to original sources

bioRxiv2025

Using social network analysis and non-invasive antibody detection to explore pathogen exposure in wildlife communities

Understanding the dynamics of infectious diseases in ecosystems shared with wildlife is a priority for preventing future threats to human, animal health and conservation. However, the collection of ecological and epidemiological data on wild populations has relied on invasive and costly methods which limited the capacity of investigation. Recent technological developments have changed this trend. In Hwange national park and its surrounding area in Zimbabwe, we combined camera trap-based ecological monitoring over a period of 12 months, covering 14 water holes with a fecal-based antibody survey in 16 large herbivore species. A survey involving 52,829 pictures as well as 629 faecal samples collected every 15 days, has shown Through the modelling of multispecies contact networks, the risk of infection exposure at species-level is predicted. Coupled with foot-and-mouth disease virus (FMDV) antibody information, the role of each species in the dynamics of infectious diseases is explored. This study highlights how community networks can provide valuable insights into the functional epidemiological role of wildlife populations. Rather than establishing transmission routes, our aim is to propose a scalable and non-invasive surveillance framework that identifies priority species and areas for epidemiological monitoring in complex ecological systems. Significance StatementMonitoring disease circulation in wildlife is often hindered by the difficulty of collecting epidemiological data. We propose a novel non-invasive approach that combines species interaction networks derived from camera-trap data with non-invasive antibody detection to explore the exposure patterns of large herbivore communities to foot-and-mouth disease virus (FMDV). By linking the position of species in contact networks with their immunological status, we demonstrate the potential of using ecological centrality as a proxy for identifying key hosts in transmission or indicator species for pathogen circulation. Beyond FMDV, this framework can be adapted to other pathogens for which non-invasive immunological assays are currently being developed, making it broadly relevant for wildlife disease surveillance in remote or protected areas.

ecology↗

bioRxiv2025

From Skin to Cortex: End-to-End Spiking Neural Network Simulation of Tactile Information Flow

Autonomous systems and neuroprosthetic devices demand real-time tactile processing under strict energy and latency constraints. Designing these systems using neuromorphic principles, where communication is event-based and node activity is sparse, could improve their speed and energy efficiency. Here we present an end-to-end spiking neural network model of the ascending tactile pathway, from mechanoreceptors in the skin in humans (or whisker follicles in rodents) to cortical neurons, that operates in an event-driven neuromorphic fashion. The model comprises distinct anatomical stages, (1) three types of mechanoreceptor afferents, (2) trigeminal ganglion, (3) brainstem, (4) thalamic nucleus, and (5) three cortical layers, connected in a feed-forward hierarchy. We demonstrate the models responses to both rodent whisker deflection and human fingertip skin displacement, using information-theoretic analysis, pairwise correlation, and stimulus decoding at each layer. Our results show that tactile information is efficiently encoded and transformed at each stage: stimulus features are represented with high fidelity and reduced redundancy as signals ascend. Notably, simple linear or Bayesian decoders can reliably classify stimulus features from single-neuron activity in the thalamus and cortex for low-noise inputs, highlighting the emergence of robust neural representations. This open-source model is the first to include the mechanosensory periphery in a full tactile pathway simulation, enabling researchers to study how perturbations at any stage affect tactile encoding. Moreover, the network is well-suited for deployment on low-power, real-time neuromorphic hardware, facilitating the development of multi-layer signal processing and tactile navigation algorithms.

neuroscience↗

bioRxiv2023

Where top-down meets bottom-up: Cell-type specific connectivity map of the whisker system

Sensorimotor computation integrates bottom-up world state information with top-down knowledge and task goals to form action plans. In the rodent whisker system, a prime model of active sensing, evidence shows neuromodulatory neurotransmitters shape whisker control, affecting whisking frequency and amplitude. Since neuromodulatory neurotransmitters are mostly released from subcortical nuclei and have long-range projections that reach the rest of the central nervous system, mapping the circuits of top-down neuromodulatory control of sensorimotor nuclei will help to systematically address the mechanisms of active sensing. Therefore, we developed a neuroinformatic target discovery pipeline to mine the Allen Institutes Mouse Brain Connectivity Atlas. Using network connectivity analysis, we identified new putative connections along the whisker system and anatomically confirmed the existence of 42 previously unknown monosynaptic connections. Using this data, we updated the sensorimotor connectivity map of the mouse whisker system and developed the first cell-type-specific map of the network. The map includes 157 projections across 18 principal nuclei of the whisker system and neuro-modulatory neurotransmitter-releasing. Performing a graph network analysis of this connectome, we identified cell-type specific hubs, sources, and sinks, provided anatomical evidence for monosynaptic inhibitory projections into all stages of the ascending pathway, and showed that neuromodulatory projections improve network-wide connectivity. These results argue that beyond the modulatory chemical contributions to information processing and transfer in the whisker system, the circuit connectivity features of the neuromodulatory networks position them as nodes of sensory and motor integration.

neuroscience↗