New research has shown that focal epilepsy occurs when brain cells called astroglia are activated causing nearby neurons to generate an epileptic discharge. The findings may lead to a new research direction for neurologists studying the origins of epilepsy and seeking new drug therapies. The study, funded in part by the EU, is published in the Public Library of Science (PLoS) Biology journal.
The findings are an outcome of the four-year, seven-partner NEUROGLIA (Molecular and cellular investigation of neuron-astroglia interactions: understanding brain function and dysfunction) project, which received EUR 3 million under the Health Theme of the Seventh Framework Programme (FP7).
About 50 million people worldwide suffer from different forms of epilepsy, a disorder characterised by seizures of varying length and severity. Symptoms range from mild seizures, characterised by jerky limb movements, to severe 'grand mal' fits that involve violent muscle contractions followed by loss of consciousness. There are drugs to control epilepsy, but as yet there is no cure.
The researchers looked for the causes of focal epilepsy, also called partial epilepsy, which occurs when a large neuronal electrical discharge takes place in the brain. Led by Dr Giorgio Carmignoto from Italy's National Research Council, the team examined the cellular events in the brain that specifically involve astroglia, which are star-shaped glial cells found in the brain and spinal cord. Glial cells provide nutrients to the brain's nervous tissue and also help repair damaged brain tissue.
Dr Carmignoto and his team monitored the activity of astroglia and neurons in a series of epileptic patients using various experimental epilepsy models. They found that a period of hyperactivity in a group of neurons triggers a huge reaction among nearby astroglia. The activated astroglia in turn send signals back to neurons. This kick-starts a period of hyperactivity in the neurons pushing them towards a massive electrical discharge. The discharge then acts as a loop triggering a second wave of astroglia activity, frequently causing an extension of the seizure.
The researchers concluded that this 'loop activity' between neurons and astroglia in different parts of the brain is responsible for the activation of focal epileptic seizures.
The discovery of this neuron-astroglia interaction in the generation of focal epilepsy marks a huge step forward in the development of new therapies and drugs to control focal epilepsy.
For more information, please visit: