Nerve cells communicate with each other by releasing certain messenger molecules from one cell to another, he says. “I’m interested in a certain molecule, a protein involved in this communication process,” he says, “And what happens once the message has been delivered.”
As with a daily newspaper delivery in which the recipient has to discard or recycle the newspaper or else suffer from a volume of papers piling up in the house, the messenger molecule has to be removed from the cell or recycled in some way, says Grewer. “Otherwise, the cell will wonder if the information is old or new,” he says. “The specific mechanism used for this removal – that’s what we’re very interested in.”
Grewer, who recently received a four-year, $1 million renewal of funding from the National Institute of Neurological Disorders and Stroke, is working with the messenger molecule glutamate, commonly known as MSG.
“In the brain, glutamate is the most important molecule that transmits information,” he says. “Once it transmits the information, it’s recycled back to its original state.” This recycling is performed by glutamate transporters that move the messenger across the cellular membrane. To unravel the mechanism of glutamate transport is one of the focuses of the Grewer lab.
However, says Grewer, glutamate is toxic when it’s released to the outside of cells in an uncontrolled way, killing them. “That’s what happens to stroke victims,” says Grewer. “Information is gone as cells are destroyed and we’re trying to figure out the mechanisms of how the glutamate release works to develop means to stop it. “This could prevent the initial cascade from happening and prevent the cells from dying,” Grewer says. “If we can stop the release at the initial phase, we can solve a lot.
“We’re not expecting one magic bullet,” says Grewer, as many other factors contribute to the death of nerve cells after a stroke. “But every part of what we do can contribute to the puzzle and, cumulatively, will make a difference.”
