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How does the brain develop in such a stereotypical and precise manner? This is an important question because the formation of precise neuronal connections is strictly required for productive communication between neurons, and understanding the basic processes that specify proper connectivity in the visual system is directly relevant to treating neurological disorders involving aberrant neuronal connections and processing, such as generalized seizures, sleep disorders, and mental retardation. In addition, it is likely that the same mechanisms used to make neuronal connections during development can be manipulated in order to rewire the brain after damage due to injury or disease.

Most people believe that brain development uses a combination of inborn genetic cues (nature) and experience (nurture). Our work over the last few years has focused on this problem. To do this we have created neural systems that lack ephrins, patterned retinal activity, and both ephrins and activity and characterized the visual projections of these systems using a combination of anatomical tracing and recording techniques. We have found that visual systems require both of the mechanisms to develop.

We are also interested in generating visual neurons in a dish, using human embryonic stem cells, in order to cure visual disease.

Spontaneous waves of activity in the developing retina.