The team from France's national research centre, CNRS, reports that by acting on a protein called Trek-1, a known fatty acid target, the fats open a potassium channel, allowing potassium ions to cross cell membranes.
The findings help to explain and support a number of studies that have demonstrated the postitive impact of omega-3 fatty acids on brain health.
Polyunsaturated fatty acids, such as the widely known omega-3s, have a protective effect against certain heart diseases and are beginning to be recommended by healthcare professionals for heart health. But the new findings mean that fish oil manufacturers could have additional benefits to promote or even a future health claim.
In 2000, Michel Lazdunski and his team demonstrated that PUFAs like alpha-linoleic acid or docosahexanoic acid, found mainly in fish oils, reduced the damage to neurones caused by an ischaemic stroke or during an epilepsy attack.
Now they say that this effect is produced through the action of PUFAs on the Trek-1 protein. Published in an early online issue of the Embo journal today, they report that mice in which the gene coded for Trek-1 had been removed were much more likely to have strokes and epilepsy attacks than normal mice.
They also failed to respond to the protective effect of fatty acids on the brain, and died from minor strokes that normal mice would survive.
Strokes affect more than 1 million people each year in the European Union and are the second biggest cause of death in the world after heart disease. They are also a source of major disability for patients that survive them, causing paralysis of one side, depression or secondary epilepsy.
The findings could also help researchers to develop new treatments for these illnesses. At least 20 per cent of epilepsy patients (around 2 per cent of the population) are resistant to current medication.