Scientists have discovered a new cause for the development of temporal lobe epilepsy.
Under the guidance of the Institute of Cellular Neurosciences at the University of Bonn, a team of researchers discovered that during the early stages of the condition, the cells known as astrocytes uncouple from one another.
This leads to the extracellular accumulation of potassium ions and neurotransmitters, which cause hyperexcitability of the neurons and can give rise to the development of temporal lobe epilepsy.
Astrocytes were once considered to be little more than the 'glue' that holds the brain together, but more recently it has been discovered that they actually serve as important partners to neurons.
Professor Christian Steinhauser, director of the Institute of Cellular Neurosciences of the University of Bonn, stated: "In this condition [temporal lobe epilepsy], no functional networks of coupled astrocytes can be formed."
Using a specifically developed mouse model that recreated key characteristics of temporal lobe epilepsy in humans, the scientists discovered that coupling between astrocytes is lost very early during the development of the condition, with changes in the neurons not observed until later on.
Because astrocytic networks are missing, potassium ions and neurotransmitters, such as glutamate, which play an important role signal transmission, can accumulate in brain tissue. This leads to hyperexcitability of the affected neurons and, consequently, epileptic seizures
According to the scientists, the uncoupling of astrocytes can be prevented by releasing certain cells into the brain that will cause inflammation.
"We were able to demonstrate that uncoupling of astrocytes – at least in the early stage of epilepsy – can be reversed," Prof Steinhauser stated.
It is hoped this discovery could help with the development of new therapies to treat temporal lobe epilepsy.
Full results of the research are to be published the journal Brain, the full print version of which will be available in May. An online version has been released in advance.
Publication abstract: http://brain.oxfordjournals.org/content/early/2015/03/11/brain.awv067
Posted March 19th - http://www.epilepsyresearch.org.uk