Sclerosis of the otic capsule in the inner ear eventually results in hearing loss. This is a common occurrence in the aging human population but also can occur in specific genetic conditions such as Pagets disease, osteogenesis imperfecta, and certain metabolic disorders . In addition, extreme noise, high pitched noise, or prolonged noise , can also induce damage to the hearing mechanism. Unfortunately, if otosclerosis is not treated early in its appearance (measured by hearing tests), the hearing loss and deafness may be permanent. Our immediate interest is whether animals that have been in space and in microgravity, will develop otosclerosis and subsequent hearing loss. This could be caused by constant noise, even at a normal pitch, or by the change in hydrostatic pressure within the skull that could affect the metabolism and function of the otic capsule. The presence of such sclerosis would suggest that the human crews in space may need to be monitored for hearing loss, and also strongly supports an animal flight experiment to study the cellular/molecular mechanisms responsible for development of otosclerosis and hearing loss. Such research would benefit not only the space program but also the aging population here on earth.
The goal of this request for flight animals is to evaluate the presence of inner ear changes due to flight compared to ground controls and basal pre-flight animals. Because these samples are not fresh, or chemically preserved , and have been frozen, we do not expect to obtain much meaningful cellular detail or activity. However the otic capsule matrix and supporting tissues will be preserved and sclerosis of the matrix can be evaluated. This will be done using immunostaining for the presence of certain cytokines (TNFalpha, sclerostin, osteoprotegerin, and BMPs) which are stored and normally present in bone matrix. Fourier transform infrared spectroscopy (FTIR) and micro-computed tomography (microCT) analysis of the mineral and collagen content and their anatomical distribution will also be done to compare bone matrix and soft tissue analysis between flight, ground controls and basal animals.RESULTS:
Although experiment is described, there are no results available.
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