Seizures: An underlying feature of neuronal networks

Researchers from Inserm U1106 in Marseille, France and the University of Michigan, USA have demonstrated that brain seizures are common and similar. From flies to humans, the potential for this activity is present in all brains, including healthy ones.

Their paper, published in Brain last month (June 2014), showed that the dynamics of seizures do not vary between cause, species or brain region.

Epilepsy is defined by the occurrence of spontaneous and recurrent seizures but there are many other pathologies also associated with them including Alzheimer's, stroke, head injuries, encephalitis and brain tumours.

This recent study proposes that there is a 'barrier' preventing the brain from exhibiting seizure like events in healthy brains and that in conditions associated with seizures this barrier is disrupted by the reorganization of brain circuitry. For people with epilepsy this barrier is not as strong as it is in those with healthy brains.

In this research, the groups have started to look at the onset, time course and offset of seizures, instead of just the activity occurring during a seizure. By doing this they have found that there are only a certain number of ways that a neuronal network can transition into and out of seizures. They found that these transitions follow precise mathematical rules and were able to create mathematical models describing each pathway.

This is a new approach in epilepsy research and promises to help with finding new drugs and therapies to treat epilepsy. In a common condition where a third of sufferers do not respond to current medicines this could prove to be a big step forward.

Director of Research at Inserm and a long-term Scientifica customer, Christophe Bernard , appeared recently on French TV, explaining his work.

Paper Reference:

Jirsa VK, Stacey WC, Quilichini PP, Ivanov AI, Bernard C (2014) On the nature of seizure dynamics. Brain: 2014 Jun 11. pii: awu133. [Epub ahead of print] doi: 10.1093/brain/awu133

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