The effect of Hedgehog signaling on in vivo neuronal morphogenesis.

Leana Ramos and Alexis Tapanes-Castillo.

School of Science, Technology, and Engineering Management St. Thomas University, Miami Gardens, FL 33054

Neurons exhibit complex and diverse morphologies. The shape of a neuron has important functional implications, as it determines what signals a neuron receives and how these signals are integrated into neuronal circuits. Pharmacological data from mammalian neurons revealed that Hedgehog signaling activity regulates neurite length and branching (arborization) in vitro. Based on these findings, we are striving to understand how the Hedgehog signaling pathway regulates neuronal morphogenesis in vivo. As a model system, we are studying the multi-dendritic, epidermal sensory neurons of the fruit fly Drosophila melanogaster, an organism with evolutionarily conserved mechanisms of neuronal growth and circuit formation. We hypothesize that if we experimentally manipulate Hedgehog signaling activity, we will observe a change in dendritic arborization. Using Sholl Analysis, we are comparing dendritic arborization in larvae with reduced, increased, and control (wild type) levels of Hedgehog signaling.