In the early days of neuroscience, it was believed that the adult brain didn’t change; that the nerve paths were “fixed, immutable” and that any minor damages to the brain would become permanent. Dr. Sandrine Thuret, the head of the Neurogenesis and Mental Health Laboratory at King’s College London, has been helping to change all that, showing that new neurons are still formed in some parts of the brain. She works on two questions – how can healthy brains create new nerve cells based on dietary and behavioral changes? And do diseases such as depression and Alzheimer’s impact the brain’s ability to grow?
Thuret studies adult hippocampal neurogenesis (or AHN). The adult brain contains small numbers of neural stem cells that divide and differentiate into neurons and Thuret studies this phenomenon in the hippocampus – a part of the brain associated with mood and memory. AHN decreases with age. Elderly animals show impaired learning and memory abilities; but increased AHN is linked to improved learning and memory. AHN is reduced by stressful experiences and in animal models of depression, but many antidepressant treatments have been shown to enhance and are dependent on functional AHN. Therefore, according to Thuret’s work, AHN is a good target for counteracting the effects of ageing and stress and thus preventing cognitive and mood decline.
To study AHN, Thuret and her team use stem cells and a mouse animal model to study cognition and mood. She is currently studying the molecular mechanisms by which diet impacts AHN and affects how people learn and form new memories and how this impacts their mood. Her work has helped to identify some dietary habits that help in memory function, such as observing periods of intermittent fasting – taking long breaks between meals – eating foods rich in flavonoids such as dark chocolate or blueberries, and of course, increasing consumption of omega-3 fatty acids. Her research also shows that increasing AHN in early-onset Alzheimer’s may help to reverse the effects of the disease.
Written by Nicole Hutchison