Support cells rather than neurons may underlie some brain disorders including Alzheimer's disease, multiple sclerosis (MS) and intellectual disability, a study suggests.

The cells do not transmit nerve messages but play a vital role protecting and nurturing those that do.

Researchers at the University of Edinburgh used advanced techniques to investigate gene activity in specific types of brain cells. They then compared this information with genes known to be linked to a range of common brain conditions.

The findings showed that often it was support cells that were likely to be affected first.

In the case of Alzheimer's, support cells called microglial cells appeared to be the trigger. Damage to neurons was a secondary symptom that occurred as the disease progressed.

Myelin, the fatty insulating sheath that surrounds nerve fibres in the brain, is produced by another type of support cell called an oligodendrocyte. MS is caused by the immune system's destruction of myelin.

The research is reported in the journal Frontiers In Neuroscience.

Co-author Professor Seth Grant, from the University of Edinburgh's Centre for Clinical Brain Sciences, said: "We are in the midst of a scientific revolution where advanced molecular methods are disentangling the Gordian Knot of the brain and completely unexpected new pathways to solving diseases are emerging.

"There is a pressing need to exploit the remarkable insights from the study."