The overall objective of the group is to unravel principles of neural computations underlying sensory-motor integration in thevertebrate brain. We use the zebrafish larva as a model since it currently constitutes the only vertebrate system amenable towhole-brain recording with cellular resolution. Using one- or two-photon light-sheet microscopy, we are able to monitor the long-termactivity of the quasi-entirety of the 100,000 neurons that comprise the animal brain, as it performs basic sensory-motor tasks.
Our brain needs to constantly fuse sensory information detected by our multiple senses in order to produce a seamless coherent representation of the world. Rather than being the exception, this binding process is ubiquitous to sensory-motor integration and is implicated in most cognitive functions. Its impairment is a cause of various pathologies, such as schizophrenia or autism. Multisensory processing operates on all brain levels from primary cortices over subcortical structures up to higher associative centers, while the smallest operational units are single multisensory neurons.
Using the zebrafish larva as the experimental model and a multidisciplinary approach, including twophoton calcium imaging to monitor activity of neural networks, motor behaviours, genetic engineering techniques to label, monitor and manipulate activity of specific neurons or entire circuits and mathematical methods for data analysis, we are studying the following subjects:
1) Multimodal sensory perception:
The optic tectum has emerged as a tractable visuomotor transformer, in which anatomical and functional studies can allow a better understanding of how behavior is controlled by neuronal circuits. We are examining the formation and function of the visual system in zebrafish larvae using in vivo time-lapse microscopy and state-of-the-art “connectomic” and “optogenetic” approaches to monitor and perturb neuronal activity. We apply complementary cellular and molecular analyses to dissect this circuit and identify the neuronal substrate of visual behaviors.
The central nervous system (CNS) of vertebrates is a complex arrangement of neurons and glial cells that underlie brain physiology and animal behavior. These cells are set-up in defined numbers at specific locations from neural progenitors or Neural Stem Cells (NSCs), largely during early stages of life. In addition, the maintenance of NSCs in the brain until adulthood is a general phenomenon, likely crucial to late adaptation events. Indeed, defects in adult neurogenesis have been correlated with neurodegenerative and mood-related disorders, and also occur during ageing.
Our research team recently appointed at the Brain and Spinal Cord Institute will serve to close the gap between clinical and basic research in neuroscience. We will functionally characterize genetic variants for neurodegenerative diseases and develop models using these mutations. Further, we will use these models to identify and validate compounds with neuroprotective properties. Thus, our research will serve as a ring between clinical and basic research and we hope it will advance both these fields of neuroscience.