Free radicals and the power of exercise
Damian is especially interested in the adaptability of the brain, in the mechanisms that allow long-term exercise to improve cerebrovascular function and understanding how this impacts on oxygen transport and clinical outcome. His research has shown that exercise is a promising countermeasure to ageing and the associated neurodegeneration. Physical activity could even help to protect against Alzheimer’s and dementia. To understand its benefits, Damian focuses on free radicals, molecules that regulate oxygen delivery to the brain, for good and for bad. Having showed for the first time in exercising humans that free radical formation increases in skeletal muscle - conventionally accepted as a bad thing given these molecules’ capacity for structural tissue damage - he has since demonstrated that, in physiologically controlled amounts, free radicals act as adaptive signalling molecules that contribute towards improving vascular health, not only within muscle but also in the brain. These adaptations allow the exercising brain to function as if it were over a decade younger, which can reduce the incidence of stroke and dementia - truly “exercising the brain for gain.” It is a dream result. The power to fight age-related neurodegeneration could be available to everyone, at no cost and without the adverse side-effects that can come with medication.
New indicators of cerebrovascular risk
Not only is Damian’s research helping improve our ability to screen for clinical disease such as atherosclerosis, he is also developing sensitive brain biomarkers that can help identify those sportspeople who are at increased risk of concussion or to those more likely to succumb to high-altitude cerebral syndromes including acute mountain sickness and cerebral oedema. These biomarkers are already in use in hospitals and on sports fields, providing more sensitive and objective biomarkers associated not only with improved performance, but also improved brain health and fitness.
As published during Brain Awareness week, Damian’s work on the impact of repetitive concussions in rugby union has the potential to change the rules of the national game. “We’re avid rugby fans here in Wales, we live and breathe rugby, and we’re keen to encourage physical activity and the benefits that has for the brain - but we’re learning more about what the long term implications of concussion are, including accelerated cognitive decline and early onset dementia. We don’t want to stop the game but provide objective biomarkers to make it safer across the spectrum of age and ability, from school children who are especially vulnerable to a lifelong brain injury, to professional players. Furthermore, our tests are designed to detect subtle traumatic brain injury in the acute setting - you can use them in the playing environment and gain immediate measurements to indicate when a player is safe to return to the pitch”.
The role of gender in oxygen transport
He has explored the difference between male and female brains when it comes to adapting to changes in blood flow to the brain. “Our preliminary findings suggest that the female brain is more adaptable compared to the male brain and better able to cope and acclimatise to the extremes of oxygen lack, or hypoxia. Female free-divers are rapidly catching up with their male counterparts and I predict, likely to surpass them given their superior ability to defend cerebral oxygenation.” Oxygen delivery to the brain could be a differentiating factor in terms of understanding the clear gender differences that characterise disease susceptibility.
While USW has a well-equipped normobaric hypoxic chamber, Damian did not study his theory purely in a lab in Wales. True to form, he regularly organises research and climbing expeditions to South America with students who are interested in the combination of science and adventure. A recent expedition to Chile and Bolivia focused on how the human brain acclimatises to the hypoxia at high altitude and to what extent this is influenced by gender. Alongside the scientific objective, the team also completed a climbing objective to confirm their findings. They summited the highest peak in Bolivia, Nevado Sajama at over 6 500 metres, and played a game of football to demonstrate how females are better equipped to cope with the extremes of exercise and hypoxia.
The ideal combination of science and adventure
Damian’s passion for what he does is obvious. “As we explore unique insights into fundamental physiological mechanisms, we’ve got a fantastic opportunity to incorporate a real sense of adventure in some of the research that we do. Our clinical and applied models allow us to ask precisely why we have evolved with a brain that is so reliant on oxygen and to what extent does oxygen available to the brain influence our trajectory towards disease.”
Conducting experiments in these environmental extremes also requires special equipment - and that’s where ADInstruments is proud to help. As well as recording of a complex array of real-time signals including heart rate, blood pressure, breath by breath expired gases, brain blood flow, activity and oxygenation – Damian also needs the equipment to be compact, portable and robust. “ADInstruments hardware, including the PowerLab in particular, has revolutionised what we can do scientifically in these challenging environments and we can truly bring our laboratory to the mountain. The equipment has performed admirably in extreme environments characterised by extremes of temperature, wind and hypoxia. When you spend a lot of money to get a piece of equipment up into the mountain ranges, you want that equipment to work when you test your human volunteers - fortunately the PowerLab is especially durable.” He adds, “You can even rest your coffee on them - which is a great thing when you’re climbing!”
The future of brain research
Damian is especially keen to explore the burgeoning field of oxygen sensing - how the brain senses hypoxia and what signals it deploys to help our bodies adapt and ultimately survive. He is also keen to push a new field known as quantum physiology, “We think we can explain physiological processes in mathematical terms and lean on quantum principles to understand how the brain interacts with oxygen - which is in and of itself a free radical. Our extreme athletes may have harnessed unique features of quantum mechanics to gain a physiological and performance advantage! It’s very new and exciting, quite speculative in some ways, but it’s these types of big ideas that help move the neuroscience field forwards.”
While the path of future research is hard to predict, we know it will include applied investigations into how the human body copes with hypoxia. “For me, the expeditions are about providing opportunities and inspiring the next generation of researchers to address some of the really complex questions that we are still wrestling with. And it’s a great way to show them that there is an opportunity to be creative, to combine excellent science with a sense of adventure and in so doing, have a lot of fun.”