Hearing restored successfully in mammal ear

Washington, Jan 10 (ANI): Massachusetts Eye and Ear and Harvard Medical School researchers have demonstrated for the first time that hair cells can be regenerated in an adult mammalian ear by using a drug to stimulate resident cells to become new hair cells. The result - it lead to partial recovery of hearing in mouse ears damaged by noise trauma. This finding holds great potential for future therapeutic application that may someday reverse deafness in humans. "Hair cells are the primary receptor cells for sound and are responsible for the sense of hearing," senior author, Dr. Albert Edge, of Harvard Medical School and Mass. Eye and Ear said. "We show that hair cells can be generated in a damaged cochlea and that hair cell replacement leads to an improvement in hearing," he said. In the experiment, the researchers applied a drug to the cochlea of deaf mice. The drug had been selected for its ability to generate hair cells when added to stem cells isolated from the ear. It acted by inhibiting an enzyme called gamma-secretase that activates a number of cellular pathways. The drug applied to the cochlea inhibited a signal generated by a protein called Notch on the surface of cells that surround hair cells. These supporting cells turned into new hair cells upon treatment with the drug. Replacing hair cells improved hearing in the mice, and the improved hearing could be traced to the areas in which supporting cells had become new hair cells. The findings are published in the journal Neuron. (ANI)