Grant: CIHR Fellowship

The fastest growing age group in Canada is comprised of those 65 years of age and this population is expected to double within the next 25 years. With natural adult aging, muscles and nerves of the human body undergo degenerative changes which are characterized by reductions in strength due to the loss of muscle mass. The results of this ongoing process lead to muscle weakness and an overall decline in function, which is highly linked to physical disabilities, risk of falls, quality of life, and ultimately, mortality. However, to date, much focus has been placed on age-related diseases (e.g., cancer, heart disease) and little is known about the biological mechanisms of natural aging. Therefore, I will study how natural aging alters the functioning of muscles and the nerves that supply them. I will use a unique technique, known as microneurography, a research tool in which recordings are made in awake humans using small needle electrodes (i.e., similar to acupuncture needles) inserted through the skin and into a nerve branch. This technique will allow me to record from single cells activating the muscles as well as individual sensory receptors that feed information back from the muscles to the spinal cord and brain. Because this technique permits a level of investigation currently unparalleled by other methodologies, I will determine how factors associated with adult aging may impair muscle function, and hence, performance during activities such as lifting objects or standing balance. The findings of my proposed experiments will relate to the known difficulties and limitations elderly individuals have with performing tasks involved with activities of daily living. Through understanding the mechanisms underlying these limitations, future studies will focus on the design and evaluation of functional training programs for improved muscle function and quality of life in older adults.