Our laboratory studies neuronal structure and development from a cell biological perspective. We are particularly interested in neuronal polarity--the structural and functional differences between axons and dendrites--and the mechanisms that the underlie polarized targeting of membrane proteins. Using viral transfection methods, we have identified some of the signals that target integral membrane proteins to dendrites and are using this approach to study targeting at early stages in the development of polarity. We have also developed methods for labeling axonal and dendritic proteins with GFP in order to visualize their transport in living neurons. We are equally interested in how polarity arises in development.

We have shown that neurons initially extend several unspecified processes, which appear to compete with one another to become the cell's axon. When one acquires axonal characteristics, the remainder become dendrites. Current work concerns the cellular events that underlie determination of the axon, with a particular focus on analyzing membrane traffic. Other efforts concern cytokines that specifically enhance dendritic growth and branching and studies to elucidate the transport and targeting of mRNAs to postsynaptic sites in dendrites. From a technical standpoint, we use cultures of rat hippocampal neurons for our work and place heavy emphasis on microscopy and live cell imaging. We have also begun to use the techniques of nanofabrication as a means for controlling the spatial interactions between neurons and soluble and substrate-attached signaling molecules in their immediate environment.