Single neuron connectomics and functional mapping in visual cortex (360G-Wellcome-099692_Z_12_Z)
Understanding how cortical connectivity organizes cortical computations is a long-standing challenge in neuroscience. I propose to investigate the relationbetween circuit connectivity and circuit function in the primary visual cortex(V1). To this end, I will deploy a novel monosynaptic retrograde tracing strategy based on rabies virus to identify and functionally characterize the network of neurons that connect to a given postsynaptic V1 neuron. This network constitutes the neuron's "presynaptic connectome": it determines the neuron's functional responses and coding strategy. To measure and manipulate neuronal activity with single cell resolution, I will combine this approach with two-photon imaging of genetically encoded calcium indicators, with optogenetics, and with single-cell patch clamp recordings. My first aim is to establish how cortical connectivity governs sensory representation by population of neurons. To what extent do synaptic connections in V1 determine which neurons will fire together in response to sensory input? Recurrent connectivity in V1 microcircuits may constrain population responses to stereotyped patterns of activation (sensory representations) coding for specific features in the visual scene. My second aim is to elucidate how receptive field properties of V1 neurons originate from the interplay between neuronal microcircuits, and within them, from synaptic interactions among different cell classes.
£162,047 25 Jun 2012