Brain tissue aids stroke drug study

Slices of live human brain tissue could provide an important intermediate step between animal studies and human clinical trials in finding a drug that can help limit damage from strokes, said researchers at the Medical College of Georgia.

Sergei Kirov, the director of MCG's Human Brain Bank, is testing drugs on this tissue in an effort to find the neuroprotective drug that has eluded researchers using other methods.

"Since many drugs work in animals but then fail in humans, I thought this might be a good starting point to try this medication in testing in the human tissue," he said. "Human tissue might help us to validate our ideas that we're getting from animal studies."

The theory goes that in strokes there is an immediate focal point of damage from the sudden loss of oxygen and glucose that causes the neurons to lose their electrical integrity, called anoxic depolarization. This typically happens within minutes. There is secondary damage on the edges of the stroke area where cells will undergo waves of this effect as they struggle to right themselves for hours or days before the damage becomes permanent. It is this process, peri-infarct depolarization, that might be the best target for drugs that protect cells.

Dr. Kirov thinks a similar process occurs in traumatic brain injury and that any drug that helps protect against further stroke damage should help brain injury patients, too.

Brain tissue removed during surgery that is not needed for a diagnosis can be donated to Dr. Kirov, who slices it very thin and keeps it viable in artificial cerebrospinal fluid.

There, he can create conditions similar to a stroke and test the ability of drugs to protect the cells from the depolarizing effect.

"He can look at a biological effect on human cells and on this anoxic depolarization, which many people think is a major mechanism of cell death during stroke but nobody has been able to really study," said co-investigator David Hess, the chairman of the Department of Neurology at MCG. "We may need a whole new class of drugs to block it."

The human tissue won't replace animal testing or animal studies, Dr. Kirov cautioned.

"It might help us to decide if we are completely off or if there is some chance" it will work, he said.

Reach Tom Corwin at (706) 823-3213 or tom.corwin@augustachronicle.com.