Movement enables animals to sense and explore their environment, but also challenges them to discriminate external stimuli from those triggered by their own movements. For example, during eye and head movements images sweep rapidly on our retinas, yet we do not perceive the world blurring away. This perceptual phenomenon indicates that the visual pathway may predict, discern or and cancel out self-generated visual signals resulting from body movements. To discover the architecture of the pathways orchestrating this visuo-motor processing, we develop and deploy methods for high-throughput mapping of synaptic connectivity at single neuron level, based on viral tracing, optogenetics and dendritic imaging. We will then combine these methods with two-photon functional imaging to record how visual and motor signals interact in circuits of connected neurons, both during active visual exploration and visual pursuit tasks.

Neurons have mesmerizing dendritic trees, whose purpose has puzzled scientists for decades. Individual dendrites may operate as an independent processing unit of specialised synaptic inputs, capable of driving the soma with active properties, acting as coincidence detectors or gating drive from other dendrites. This functional compartmentalisation is thought to expand neuronal computational capabilities, and has inspired powerful models of neuromorphic computing. However, so far, it has been difficult to test these theories with causal, dendritic recordings and manipulations in vivo. To test these theories, we are developing methods to simultaneously map synaptic inputs and outputs in single neurons, and to causally probe the function of dendrites in vivo. These include simultaneous synaptic glutamate and calcium imaging, optical pruning, and high- density electrophysiology.

Brain circuits are composed by a myriad of interconnected inhibitory and excitatory neuronal cell types, which differ in connectivity, morphology, biophysics, and gene expression. Understanding the functional relevance of each of these circuit elements is fundamental problem in neuroscience. Are there genetically defined neuronal ensembles devoted to specific sensory, motor or cognitive functions? Is the function of each neural type conserved or flexibly repurposed across different brain areas? To what extent the properties of a neuron are plastic, shaped by experience, or statically defined by gene expression? To address these questions, we leverage large-scale 2P calcium imaging and optical manipulations to characterize the function large populations of neurons;  then we measure gene expression and classify recorded neurons using spatial trascriptomics.