Epilepsy that does not respond to drugs may be halted by transplanting a specific type of cell into the brain, according to a new study conducted by US researchers and published online on Sunday in the journal Nature Neuroscience.

The study, the first ever to report stopping seizures in mouse models of adult human epilepsy, raises hope for a similar treatment in severe forms of the disease.

Anti-epileptic drugs and other therapies reduce seizures in about two-thirds of patients. The remaining one-third, however, do not respond to any form of therapy, and those who take drugs can experience harmful side effects.

Researchers with the University of California at San Francisco injected new born inhibitory nerve cells called Medial Ganglionic Eminence into the hippocampus in the brains of adult epileptic mice. They found that the treatment eliminated seizures in half of the treated mice and dramatically reduced the number of seizures in the rest.

In addition to having fewer seizures, treated mice became less abnormally agitated and less hyperactive.

Analysis of the mice brains suggested that the new cells became fully incorporated into the brain regions where they were injected.

The researchers said that others had previously used different cell types in rodent cell transplantation experiments and failed to stop seizures.

"Our results are an encouraging step toward using inhibitory neurons for cell transplantation in adults with severe forms of epilepsy," said lead author Scott C. Baraban in a statement. "This procedure offers the possibility of controlling seizures and rescuing cognitive deficits in these patients."