Michael Bastiani

On a clear night deep in the Wasatch the sky is painted by starlight – you can see about 5000 stars! But that is only a tiniest fraction of their total number. There are 100 billion stars in our Milky Way Galaxy, that is 20 million times more stars than the ones you can see. That unfathomable number is how many nerve cells are in your brain; your mind is as big and complex as the stars in Milky Way Galaxy. Moreover, those neurons form connections, and are signaling to each other. But the connections and networks must be correct for each of us to be the talented human beings that we are.
Mike Bastiani spent his career studying how the brain forms these connections in a reliable and correct manner among the number of those signaling neurons. The scale we are talking about here is worth mentioning. Nerve cells are only 30 micrometers in diameter but must send a thin process called an axon up to one meter away to form the correct connection to its target cell. Let's pretend that you're a nerve cell. That would be equivalent to your hand crawling on the ground for 85 miles – all the way from Salt Lake City to the Idaho state line.(That would be a pretty remarkable journey for a human hand).
Mike first studied this process in grasshoppers, demonstrating that each of what he identified as sprouting growth cones on the end of the nerve’s axon follows a specific path, making contacts with particular cells along the way. His laboratory identified unique proteins on the surface of these tracts of axons that acted as guides for growth cones that followed along the established roadways, changing direction of migration – as if reading a map.
With his labeled-pathways hypothesis in hand, Mike began to study growth cone behavior in intact (not dissected) transparent nematode worms. His lab was the first to characterize growth cones in an unperturbed environment and unexpected behaviors of growth cones, their collapse – a once discarded notion — and their re-creation of the growth cone on the other side once they’ve successfully navigated a barrier.
Using this assay, his laboratory then discovered an entirely new process in nervous system development. By continuing to observe the nervous system after wiring was complete, he and his team identified genes that stabilized it. These genes “told” neurons to set aside their youth, to stop sprouting growth cones, and to stabilize the existing network.
Initially, Mike observed in yet another subject model, C. elegans, what most believed: that damaged axons could not regrow and shut down. But then seven hours following the damage done to axons by a laser, he saw that growth cones sprouted from the stump and regrew to their target, though admittedly not perfectly. He then screened for mutants that could not regrow axons and discovered a protein called DLK-1 that was required for the reappearance of a new growth cone. Importantly, if he caused the neuron to make DLK-1 before the axon was damaged, the growth cone sprouted immediately after being cut and was able to find its correct target.
Subsequently, these experiments have been validated in mammals. It turns out, the nervous system can heal itself, and if the neurons can be prodded to respond to damage earlier, can regrow, and re-establish functional synaptic contacts. These experiments have led the neuroscience community to explore repair of damaged nervous systems such as spinal cord injuries that result in patient paralysis.
Mike Bastiani retired from the School of Biological Sciences this past May, but as of 11 am this morning can still be seen at his microscope room repairing the laser. Apparently, there’s more work to be done. ~ Erik Jorgensen