Traditionally viewed as supporting actors, cells known as glia may be essential for the normal development of nerve cells responsible for hearing and balance, according to new University of Utah research. The study is reported in the January 6, 2005 issue of Neuron and is co-authored by scientists at the University of Washington.
"Using zebrafish as a model, we've demonstrated that glial cells play a previously unidentified role in regulating the development of sensory hair cell precursors -- the specialized neurons found in the inner ear of humans that make hearing possible. This research increases our understanding of how nerve cells develop and whether it may be possible to regenerate these types of cells in humans one day," said Tatjana Piotrowski, Ph.D., assistant professor of neurobiology and anatomy at the University of Utah School of Medicine.
Scientists long have known that glial cells, or simply glia, are essential for healthy nerve cells. However, in the last 10 years scientists have learned that glia aren't just "glue" holding nerve cells together. Glia communicate with each other and even influence synapse formation between neurons.
Piotrowski's research in zebrafish focuses on the development of sensory neurons known as hair cells. Like humans, zebrafish use hair cells to detect sound and motion. However, in humans hair cells are buried deep inside the inner ear making them difficult to access. Hair cells in zebrafish are located on the surface of their body and help the fish swim in groups and avoid predators.
"Zebrafish are a wonderful model for studying hair cell development for a number of reasons. The hair cells are exposed and can be easily seen under the microscope in the live fish. We can also visually identify the consequences of gene defects in the 200 to 300 embryos each female fish produces," she said.