The roots of epilepsy lie in an often-overlooked type of brain cell and not in the neurons as was previously thought, a new study claims. The US-based researchers hope their findings will lead to more appropriate treatments for the condition.Epilepsy is a syndrome that arises when a brain chemical, called glutamate, stimulates neurons to start firing wildly and uncontrollably, sometimes resulting in seizures or loss of consciousness. Current treatments are aimed at slowing down brain function to reduce the neuronal firing, but these have unwelcome side effects, such as drowsiness.Neurologists generally believe that epilepsy causes the production of abnormal cells called reactive astrocytes – oversized, bloated, star-shaped cells that no longer function properly in their “housekeeping” role of maintaining the brain’s optimum chemical environment.So Maiken Nedergaard, at the University of Rochester Medical Center, New York, and colleagues decided to take a closer look at the role of astrocytes in epilepsy. The team induced epilepsy in rats using five different known methods, for example lowering the level of brain calcium. They then blocked synaptic activity completely using the neurotoxin tetrodotoxin (TTX), which meant there was no neural firing and therefore no seizures in the rats.
