Epilepsy Study Gives Insight to Mood Disorders

New solutions for learning and mood disorders caused by epilepsy (search) may be a step closer to reality. Producing more brain cells might help, latest research shows.

Brain injury caused by an acute seizure can prompt the production of new cells, which researchers say is most likely the result of growth factors released from injured or dead brain cells. What remains unclear are the effects of long-term seizure disorder or epilepsy on brain cell development (search).

Addressing these issues, say researchers, is important since both human and animal studies have shown that learning and memory function are affected by epilepsy.

In lab tests, rats with the condition of epilepsy produced 64-81 percent fewer new cells in the brain’s hippocampus region. The hippocampus (search) region of the brain oversees learning, memory, and mood.

Coaxing the brain into making up for the shortage could make a difference.

“In the future, we could theoretically treat chronically epileptic patients with stem cell factors that induce new neuron production and see if it alleviates their learning and memory problems and depression,” says Duke University’s Ashok Shetty, PhD, in a news release.

Shetty, a research professor of neurosurgery, worked on the study with Duke colleagues and experts from Durham VA Medical Center in North Carolina. Their report appears in the December issue of the journal Neurobiology of Disease.

Exercise, enriched environments, and antidepressants could also help. “All of these treatments are known to considerably increase adult brain cell production [neurogenesis] in the hippocampus,” says Shetty.

Boosting brain cell production might even curb seizure activity. In Shetty’s study, rats producing fewer new brain cells were more likely to have epilepsy.

However, it’s not just a matter of pumping out more brain cells. There appears to be a fine line between overdoing it and falling short.

Sudden seizures can trigger a fast and furious spurt in brain cell production, the study shows. But that wasn’t good news.

The rats with sudden seizures couldn’t handle all those new brain cells at once. It was too much, too soon. As a result, the new brain cells weren’t effectively used. In fact, the spurt just made matters worse.

Finding the best solutions will take more work. Meanwhile, Shetty sees promise in the process. “Understanding the brain’s long-term response to epileptic injury will enhance our ability to treat the disease,” he says. He notes that the decline in brain cells may be to blame for the decrease in memory and learning observed in epilepsy.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Hattiangady, B. Neurobiology of Disease, December 2004; vol 17: pp 473-490. News release, Duke University Medical Center.