Grant: Operating Grant

Concomitant with aging, the elderly often find they are more easily distracted by multiple stimuli and increasingly unable to memorize events with sufficient context that in their youth would have made up for these distractions. Context is beneficial for memory and interference is detrimental. For example, the reader may experience memory interference when reading about our research and confuse it with another study that deals with memory decline in old age. However, upon re-reading our proposal and relating it to the concept of adult neurogenesis, the reader will realize that our work is distinct. We propose that such decline in memory is due to decreased production of new neurons in the aging brain. New neurons are generated within the hippocampus, the brain region crucial for learning and memory, and within the olfactory bulb, responsible for sense of smell. Evidence suggests a crucial role of neurogenesis in normal function of the adult brain, but the ability to produce new neurons declines drastically with age. Depletion of new neurons by a variety of experimental research techniques causes behavioural deficits consistent with impaired brain function. By identifying functional roles for new neurons, the goal of this research is to explain behavioural symptoms. We will inhibit the formation of new neurons in young animals by application of radiation and measure the resultant loss of function to determine the role of these neurons in certain types of learning and memory. We then will increase generation of new neurons by increasing physical activity and by drug treatment. If the defined types of learning and memory require new neurons, then our treatment should enhance those functions. Our study will produce results that are important for better understanding of the normal function of the brain and also for its decline with age. Our work will establish a basis for development of therapy by which to improve certain types of learning and memory.