The overall goal of our research program is to understand how neuronal cell type diversity within sensory tissues contributes to circuit formation and allows sensory systems to process complex stimuli. Establishing the right connections between neurons is a fundamental requirement for sensory systems, as sensory input is often conveyed to the brain through a vast diversity of neuronal cell types making selective connections within the network. What is the underlying function of this neuronal diversity? Does each subtype of sensory neuron make connections with the right partners in a genetically predetermined way, or are those connections based on the sensory input to the system?

    One sensory tissue in which we can address these questions is the retina. The retina is a nervous tissue that lines the back of your eye. What the eye sees is complex – each image received by the retina is a combination of features like outline, contrast, color, motion and direction, among others. That is a lot to take, so in most vertebrate retinas, effective processing of visual information is achieved by splitting different aspects of the visual stimulus into separate tracks called ‘parallel pathways’. This is where neuronal diversity comes into play – different retinal cell types tend to handle only specific aspects of a visual stimulus using a kind of “divide and conquer” strategy. But how does this happen? Is selectivity for color or contrast a property of the neuron’s shape, or the type of input it receives, or its unique set of membrane receptors, or a combination of all of these factors? Furthermore, are these characteristics immutable, or a product of the cell’s early experience and surrounding synaptic contacts?

    We address these broad questions in retinal cell biology and circuit function in the retinas of mice and skates (a type of cartilaginous fish closely related to sharks) by using a combination of molecular, anatomical and neurophysiological approaches