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 on mice.
Scientists from the University of California, San Francisco controlled seizures in epileptic mice with a one-time transplantation of medial ganglionic eminence (MGE) cells, which inhibit signalling in overactive nerve circuits, into the hippocampus, a brain region associated with seizures, as well as with learning and memory.
Cell therapy has become an active focus of epilepsy research, in part because current medications, even when effective, only control symptoms and not underlying causes of the disease, according to Scott C Baraban, who led the study.
In many types of epilepsy, Baraban said, current drugs have no therapeutic value at all.
"Our results are an encouraging step toward using inhibitory neurons for cell transplantation in adults with severe forms of epilepsy.
"This procedure offers the possibility of controlling seizures and rescuing cognitive deficits in these patients," Baraban said.
During epileptic seizures, extreme muscle contractions and, often, a loss of consciousness can cause seizure sufferers to lose control, fall and sometimes be seriously injured.
The unseen malfunction behind these effects is the abnormal firing of many excitatory nerve cells in the brain at the same time.
In the study, the transplanted inhibitory cells quenched this synchronous, nerve-signalling firestorm, eliminating seizures in half of the treated mice and dramatically reducing the number of spontaneous seizures in the rest.
In another encouraging step, researchers reported that they found a way to reliably generate human MGE-like cells in the laboratory, and that, when transplanted into healthy mice, the cells similarly spun off functional inhibitory nerve cells.
In the current study, the transplanted MGE cells from mouse embryos migrated and generated interneurons, in effect replacing the cells that fail in epilepsy.
The new cells integrated into existing neural circuits in the mice, the researchers found.
The study was published in the journal Nature Neuroscience.
