Michael Granato (University of Pennsylvania)
MolBio Seminar Series
For the past 15 years, research in my laboratory has focused on the assembly and plasticity of circuits underlying zebrafish motor behaviors. My laboratory was the first to perform genetic screens and isolate mutants specific for prepulse inhibition and learning behaviors. My laboratory was the first to demonstrate a critical role for secreted Wnt proteins in the formation of vertebrate neuromuscular synapses. My laboratory was the first to develop a model in which the entire process of peripheral nerve degeneration and regeneration, including interactions with other cell types such as immune cells, can be visualized in a live, intact vertebrate.
I have successfully trained five predoctoral and six postdoctoral fellows. I am active in the zebrafish community, having co-organized the 2010 International Conference on Zebrafish, and being the current co-director of the Zebrafish course in Wood Hole.
Seeing is believing: how cellular interactions shape peripheral nerve regeneration
Unlike axons of the central nervous system, axons of the peripheral nervous system have retained their ability to regrow even after complete nerve transection. Yet despite their unique ability to re-make functional connections with their original targets and the possible implications for regeneration in the CNS, we know remarkably little about how peripheral axons re-connect with their appropriate synaptic targets. This is in part because the dynamic behavior of injured or transected axons as respond to insults, interact with neighboring glia cells, and begin to pioneer a path to the original targets, has not been examined in real time, in intact vertebrate animals. Similarly, the signals glia cells provide during the early phase of regeneration, and how changes in the extracellular matrix direct re-growing axons are not well understood.
The goal of my laboratory is to define the cellular and molecular mechanisms that enable and direct severed peripheral axons to their synaptic targets. For this, we have established a laser based nerve transection model in zebrafish, enabling us to visualize the cellular behaviors of transected axons and neighboring cell types simultaneously, in real time, in an intact vertebrate animal. I will discuss ongoing projects to understand the interaction between injured axons and neighboring cell types, and how modification of the extracellular matrix enable re-growing axons to make navigational choices.
Free and open to the university community and the public