How blood could age the brain

Our memories deteriorate across the lifespan, and this poses increasing public health challenges. A brain structure known as the “hippocampus” is essential for establishing memories and, critically, may also be the only site where new brain cells (neurons) are produced throughout adulthood (adult neurogenesis). Neurogenesis appears to be important for normal memory function, but it decays with age, while conversely, exercise increases it. Though the causes remain unknown, it has been found that proteins and metabolites in the blood could regulate adult neurogenesis, and that the levels of these molecules change as we age and with physical activity. In my research, I aim to identify proteins and metabolites that display opposing relationships with ageing and exercise, which could provide early detection for cognitive decline and new targets for intervention. I recently identified a protein (known to occur in new brain cells) in the hippocampus and three metabolites in blood that are responsive to exercise and aging, with one metabolite displaying an opposing relationship. By comparing these results with future analyses of proteins in blood and cerebrospinal fluid (which envelopes the brain), I hope to arrive at a mechanistic pathway by which exercise could ameliorate age-related cognitive decline via neurogenesis.