ERK is well-known for its role in cell growth and division, but this is the first study implicating it in excitotoxic pathways.

The HMS investigators mixed cultured brain cells with an ERK-blocking drug, PD098059, and induced seizures in the cells (seizures are also thought to utilize excess glutamate to promote death in neighboring cells). They found that when the ERK was blocked, the cells were safe from deadly glutamate exposure.

In a HMS press release, Allessandro Alessandrini, assistant biologist at Massachusetts General Hospital and a co-author of the study, says, "The exciting thing about this is not only that it deciphers an initial stage in the pathway of stroke, but also suggests that a pathway thought to be involved in cell proliferation may lead to damage early on in ischemia."

Alessandrini and his colleagues carried out experiments of their own, where they injected the ERK-blocking drug into seven mice and then blocked the blood vessels in their brains.

They found that, on average, the region of cell death in mice receiving the ERK-blocking drug was 55 percent smaller than that of mice not given the drug. Alessandrini noted that in his study, the ERK-blocking drug was administered to the mice before or at the beginning of a stroke, a situation that may not be practical in humans. However, researchers believe that the findings do give hope for discovering other possible ways of stopping a stroke after it has begun.

"What is especially exciting is that this basic excitotoxic mechanism may be important for many types of neurodegenerative disease," Murray says in a HMS press release.