Abstract

A central aspect to computation in the brain is to elucidate how information is transformed by the neural circuits of brain regions, how inputs are transformed to outputs. Here, I will discuss how we approach this work in the mouse olfactory system. Odours in natural settings are transported by complex, often turbulent airflows. I will discuss the information that is contained in the spatiotemporal odour plume structure, how it is represented in the mammalian brain, and how this can be accessed behaviourally. We will then use these rich odour stimuli to probe representation and processing across brain areas. To link function to structure and directly elucidate how information is transformed in early sensory areas, I will introduce correlative multimodal imaging approaches, centring around different synchrotron X-ray tomography techniques. These enable us to directly identify the anatomy of neurons previously functionally imaged in vivo across mm3 volumes. Specifically, it allows us to identify output channels corresponding to a given input channel in the olfactory bulb. Thereby we can resolve how different “sister” projection neurons differentially represent the external sensory world. Finally, I will discuss how such X-ray tomography methods can be developed to enable multimodal imaging of mm3 tissues with synaptic resolution, paving the way for dissecting neural circuit anatomy across brain areas in a scalable way.