Gabriela K. Popescu said the research focuses on the brain's receptors for the neurotransmitter glutamate, which is implicated in Alzheimer's or stroke, as well as in other conditions, such as glaucoma.
The two main glutamate receptors in the brain, NMDA and AMPA, both play critical roles in human learning and memory. Both types of receptors are made of four sub-units and within each receptor the sub-units are organized in pairs called dimers, Popescu said.
Because the receptors are so similar in structure, Popescu said, it was assumed they function in much the same way.
"But when we altered the dimer interface, the site where two sub-units come together within each pair, we found that the NMDA receptor works just the opposite of the way that the AMPA receptor works," Popescu said in a statement. "Cementing this interface in AMPA receptors leads to more activity, whereas we found just the opposite to be true in NMDA receptors."
The study, published in the journal Nature Communications, found by locking the sub-units together, the researchers achieved a marked reduction in NMDA activity and, subsequently, a marked reduction in the amount of calcium that enters neurons in response to the neurotransmitter glutamate.
Calcium overload due to overactive NMDA receptors eventually kills off neurons, Popescu explained, leading to the symptoms that occur after a stroke, Alzheimer's and other neurodegenerative diseases.