Usually microglia work as part of the immune system in the brain, helping to clear away cancerous cells and infections. However, tumour cells can release chemicals that mess with the normal function of microglia and encourage them to release chemicals that help the cancer spread. Scientists are exploring ways to promote anti-cancer activity in glial cells while inhibiting tumour-promoting activity. This work may form the basis of new treatments for brain tumours.

EMBL scientists studied microglia using an electron microscopy technology (FIBSEM) in which an ion beam strips away thin layers of the sample so an image can be taken of each layer. This produces thousands of detailed images. Managing the volume of data, analysing and integrating it into 3D views can only be achieved using computers and specialised programs. EMBL is a leader of the Euro-BioImaging collaboration which helps scientists with the handling and processing of such complex image data.

Microglia exist in many species, including some organisms from which humans diverged a very long time ago in evolutionary terms, such as snails, flies and leeches. Human microglia differ from those in all other species in terms of certain genes that are expressed as proteins within them. This may help explain how the cells play a role in the degeneration of human brains in old age.

Malfunctioning microglia are linked to various forms of dementia in older people. As life expectancy increases and, in some countries, birth rates fall, older people are becoming a larger proportion of the population. Research institutes and commercial companies have invested heavily in investigating diseases of old age. But treatments for dementia have proved illusive, so new approaches are needed.