Animals have a wide range of mechanisms for detection of airborne or waterborne sound waves, as well as sensing changes in pressure. Detection of sound involves sensory cells called mechanoreceptors. Hearing, defined as the ability to detect, or sense, changes in the wavelike properties of air or water pressure, is tied to the proper functioning of mechanoreceptors. Damage to the mechanoreceptors disrupts the animal’s ability to detect. It is currently believed that the inability to detect is a result of damage to the hair cell brought about by the loss of tip linkages. These tip linkages function to help maintain the proper arrangement of the hair cell. In addition, tip linkages have been implicated in the proper functioning of the ion channels necessary for hearing to occur. Damage such as this may be a result of noise-induced trauma in higher animals. Mechanoreceptors in the inner ear of mammals have very limited ability to repair damage inflicted upon them, such as that caused by exposure to loud noise.
Hair cells of the sea anemone Haliplanella luciae function similarly to hair cells of higher animals, but exhibit striking differences as well. Sea anemones use the hair cells that cover their tentacles to detect vibrations in the water-column created by their moving prey. Hair cells are damaged during prey capture and must be repaired. In contrast to mammals, repair of damaged hair cells in the sea anemone is possible. The anemones secrete a protein complex believed to be responsible for the repair of damaged hair cells. It is believed that tip linkages and accessory proteins are components of this protein complex. The anemones can be induced to secrete this protein complex under experimental laboratory conditions. My research involves the isolation and characterization of components of this protein complex as well as determining the mechanism by which repair occurs. Additional studies involve the application of repair proteins to traumatized hair cells of the zebrafish, Danio rerio. These studies involve pharmacology, TEM, immunohistochemistry and a variety of other light microscopy techniques.
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