Current research in the laboratory includes a study of how a signaling protein, Hedgehog, is transported along axons of the developing visual system, a means by which the retina controls the number of target neurons for retinal axons in the brain. We study the converse problem of how contact between photoreceptor axons and their targets in the brain influences the final stages of photoreceptor neuronal differentiation, including the development of synapses. With respect to the function and plasticity of the adult visual system, one investigation in the lab asks how visual experience is remembered, particularly with regard to the wavelength of light, as flies make directional choices in a walking maze. The aim of this project is to determine where and how such memories are encoded. Another study looks at how a protein involved in synaptic plasticity is synthesized locally in response to environmental inputs that produce a memory. A long-term goal of our work is to identify genetic differences that underlie behavioral changes associated with speciation, and relate these to developmental and functional differences in the nervous system.