Discipline: Biological Sciences
Subcategory: Biomedical Engineering
Room: Exhibit Hall A
Elias Wojahn - University of Minnesota
Co-Author(s): Vanessa Hui-Ho Chang, Johns Hopkins University, Baltimore MD; Ananya Swaminathan, Johns Hopkins University, Baltimore MD; Omid Zobeiri, Johns Hopkins University, Baltimore MD; Dale Roberts, Johns Hopkins University, Baltimore MD; Oliver Stanley, Johns Hopkins University, Baltimore MD; Kathleen Cullen, Johns Hopkins University, Baltimore MD
Calcium and Integrin Binding Protein 2 (CIB2) is found in the stereocilia of auditory inner ear hair cells. In humans, mutations in CIB2 have been found to be a cause of Usher syndrome type 1J (Riazuddin et al, 2012). Usher Syndrome is a cause of hereditary deafness in humans, but may also be responsible for vision loss and vestibular dysfunction (NIH). Previous research has focused most heavily on hearing loss, with prior research into vestibular dysfunction associated with Usher Syndrome only determining that it exists (Alagramam et al, 2005, Sun et al, 2001). It was hypothesized that mice homozygous for the CIB2 mutation will exhibit vestibular dysfunction because the vestibular sense is reliant on its own set of hair cells in the inner ear as well. To test this hypothesis, mice were divided into three groups and their vestibular sense assessed through a series of tests. The three different groups were homozygous for the mutation, heterozygous for the mutation, and the control of wild type mice that lacked the mutation. The different tests were a balance test in which it was seen how long mice could balance on a rotating rod, and the time it took a mouse to cross a balance beam. Mouse behavior in an open field was also observed, as vestibular dysfunction can manifest through circling behavior. Lastly, the mice’s Vestibulo-Ocular reflex was tested by moving the position of the head and tracking the position of the eyes in response. In all tests, it was found that homozygous mice consistently underperformed relative to the heterozygous and control groups indicating vestibular dysfunction was present in that group. Homozygous mutant mice balanced for less time–if at all, exhibited more circling behavior, and demonstrated weaker eyeball responses to head movement. For future studies, it would be valuable to use these mice in a study examining the vestibular evoked potential as these mice exhibit vestibular dysfunction. This would allow the discovery of more knowledge about the vestibular sense pathway which is necessary for creating and improving a possible vestibular prosthetic.
Funder Acknowledgement(s): NIH-NINDS 1R25NS107167-01; Johns Hopkins University; NIH DC2390
Faculty Advisor: Kathleen Cullen, firstname.lastname@example.org
Role: During the course of this research, I participated in running the rotating rod balance test and open field behavior test and recording the data. I then helped analyze the data produced from both experiments. I also began initial research into ideal vestibular sensory evoked potential recording technique.