Using MRI to elucidate the importance of physical activity to brain health and motor function in ageing

Using MRI we have previously quantified changes in cerebral blood flow (CBF) and brain oxygen extraction fraction (OEF) during low intensity exercise, showing that the increase in CBF during exercise at 30% and 50% maximal oxygen uptake is blunted in healthy, older people compared to younger counterparts. We have also demonstrated a positive association between cardiorespiratory fitness and brain grey matter volume across the adult age range, in particular in sensorimotor cortex, suggesting a causative relationship between physical activity levels and brain architecture.

This studentship will build on these observations to study a cohort of older people exposed to high levels of physical activity throughout their adulthood, and determine whether CBF and brain OEF during low intensity exercise are maintained closer to that in younger individuals, and can be explained by preservation of cardiac output in these individuals. Secondly, whether brain grey matter volume and cognitive and motor function are greater in these life-long exercisers compared to age-/gender-matched sedentary older volunteers. The project will also investigate whether pharmacologically blunting increases in cardiac output during exercise in healthy, young volunteers compromises brain perfusion and increases oxygen consumption, supporting the functional association between cardiac output deficits and brain perfusion in ageing.

This project will focus on healthy individuals and will provide mechanistic insight of the physiological control and correlates of age-related changes in brain architecture and perfusion, and cardiac and motor function. In the long run, results from this project aim to provide evidence to underpin research funding validating the positive impact of exercise intervention in promoting "successful brain ageing" leading to preservation of cognitive and motor function.