Adopting MEA technology to study age-related neural network dysfunction in human stem cells

Cognitive decline and other symptoms of brain ageing are caused by a loss of connections between cells resulting in communication failure known as neuronal network dysfunction. Adaptation of the human diet to deliver specific well-tolerated protective components, either in food, as nutraceutical supplements or as mimics of conventional medicines, is a potentially attractive cost-effective strategy for preserving these connections thus promoting healthy brain ageing, particularly during the long phases of dementia. Our research goal is to identify the most effective dietary molecules and to achieve this aim, we are investigating the molecular mechanisms underpinning age-related cognitive decline and in parallel we are testing natural products with a focus on dietary polyphenols. Like many other research laboratories we have been undertaking almost all our work in mouse models and in mouse cells but it is now viewed as critical to the field that future studies are tested under more relevant conditions in human cells. This is partly because of ethical concerns regarding the use of rodents but is also due to clear species specific differences in the way that mice and humans respond to dietary interventions. It is therefore, only through adopting new approaches in human cells that we can have any real confidence that information gained can be translated into improvements in human health. Moving our research into human cells is a significant challenge for us because growing human brain cells, specifically neurones, in the laboratory is not at all straightforward and whether these cells can be used to model age-related neuronal network dysfunction has not been established. We therefore propose to make a step change in our approach by growing neurones from human embryonic stem cells rather than from mice, and combining this with state-of-the-art microelectrode array technology to record the neuronal network that forms between these cells. We will mimic age-related changes by introducing toxic proteins that are known to accumulate in the ageing brain. If successful this will deliver an advanced human cell system for studying the molecular mechanisms of brain ageing, a more physiologically relevant model for testing dietary polyphenols and ultimately we anticipate will lead to the significant replacement of mouse models for this research area.