We are investigating two neural circuits that are involved in the processing of visual information - the retina and the visual cortex. The question that guides our research is “how do synapses in the visual system contribute to the extraction and transfer the information in a visual stimulus?”.
How do synaptic machines function within neural circuits? We have developed fluorescent reporter proteins by which the electrical activation of synapses and the resulting output - vesicle fusion – can be monitored across hundreds of neurons simultaneously. By applying multiphoton microcopy to transgenic zebrafish and mice expressing these reporters we can observe synaptic activity in vivo as the visual system responds to stimuli. Most of our work has investigated the retina of zebrafish, but we are now also working on the synaptic basis of computations in the visual cortex of mice. Our general aim is to understand how the short-term platicity of synapses contributes to the control of tuning and responsitivity within these circuits. We are particularly interested in “network adaptation” - changes in the way that visual stimuli are processed by the neural circuit according to the recent history of activity.
Our approach to investigating these questions involves a combination of techniques, including electrophysiology, molecular biology, multiphoton imaging and computational modelling.