ARRA: Molecular mechanisms of aging in the intrinsic laryngeal muscles

This application is in response to the Availability of Recovery Act Funds for Administrative Supplements Program (NOT-OD-09-060): NIDCD ARRA Administrative Supplements Providing Summer Research Experiences. The parent grant (R03 DC007983) explores the mechanisms of laryngeal muscle dysfunction in aging. In the elderly, functional denervation of the intrinsic muscles of the larynx compromises voice quality and impairs the ability to communicate and remain socially engaged. Laryngeal dysfunction may also cause dysphagia and increased risk of aspiration. Studies supported by the parent grant have demonstrated that the aging posterior cricoarytenoid (PCA) and thyroarytenoid (TA) become weaker and slower. Moreover neuromuscular junctions (NMJ5) become smaller and less abundant in the aging rat laryngeal muscles. There is also functional evidence of denervation as aging PCA and TA become significantly more sensitive to neuromuscular transmission block This project will be now extended to test the hypothesis that age related laryngeal muscle dysfunction is due to a decrease in cytoskeltal proteins necessary for muscle maintanence. Specific Aim I will examine the effect of age on the dystrophin -glycoprotein complex in rat PCA and TA muscles. This project will generate novel data on how aging induces the loss of cytoskeletal proteins in the intrinsic laryngeal muscles, and will provide insights into the mechanisms of neuromuscular and contractile dysfunction in these small muscles. The project also serves as an ideal short-term research experience for a science educator. The identified individual will develop new skills and ideas to take back to the classroom, enhancing science education and encouraging students to pursue research careers in health-related fields.