Biomechanics and Neurobiology of Fish Locomotion
Exploring How Fish Feel Flow
Since the time of Aristotle, we have marveled at the ability of animals to walk, run, fly and swim. These seemingly simple behaviors are, in fact, the product of the interaction between the intent of the organism and the physics of the world they inhabit. How can sailfish reach swimming speeds of 68 miles per hour? How can sooty shearwaters fly 40,000 miles each summer in search of food? Understanding these principles is the goal of a broad field called biomimetics: using nature's designs to inspire man-made structures and machines. Some examples are indispensable in our everyday lives, such as airplanes, Velcro, and sonar. More and more, we are looking at how animals sense their environment to be able to successfully navigate an unpredictable world. This requires us to look not only at the shape of animals, but also how their nervous system works to gather information to paint an image of their world.
What if . . . we could design autonomous underwater robots that could patrol turbulent bodies of water to detect sources of pollution or weapons of mass destruction? One aspect of my research looks at how fish and fish-shaped objects can recycle the energy of turbulent flows to save swimming energy. Since navigating turbulence relies on sensing flow fluctuations, another part of my research looks at the organization and function of neurons in the flow-detecting lateral line hair cell system in fish.
These hair cells are identical to those found in human ears with one exception: the lateral line system is much more simple and experimentally accessible. For our work, we use zebrafish larvae. They are transparent, which allows us to visualize their internal structures, including nerve cells, and we can easily make transgenic animals in which single nerve cells are labeled with fluorescent markers.
|This makes it possible to make sense of how these cells are connected to each other and to understand how hydrodynamic information is processed and translated into swimming behaviors.
|The zebrafish is a powerful new genetic model system that also allows us to answer more medically applied questions that are impossible with mammals. For example, each year millions of people are affected by hearing disorders, many of which are the result of abnormalities in hair cells and their connections with the brain.
||Our philosophy is that before we can understand more-complicated human disorders we first need to know how healthy nervous systems work in simpler, related systems like the zebrafish lateral line.
|The knowledge we gain from this model system will ultimately contribute to treatments for certain hearing disorders.
James C. Liao, Ph.D.
Assitant Professor of Biology
Dr. Jimmy Liao graduated magna cum laude with a B.A. in biology at Wesleyan University. He earned an M.A. and Ph.D. in biology from Harvard University. He was a postdoctoral fellow and research associate with Dr. Joseph Fetcho at Cornell University.
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