Instead, the glutamate sets off a cascade of events in the neuron that results in the activation of ion channels, called TRP channels, which then remain active for a long time.
"The long-term activation of these TRP channels," says Zakon, "is the 'memory.'"
Zakon, Oestreich and colleagues don't yet understand how the stimulus leads to the long-lasting activation of the TRP channel. They are pursuing further studies.
"We're looking at the general idea that we have long-term changes in the brain that affect the computation that neurons do," says Zakon. "We have ion channels [in the neurons] and we know those are activated. The mystery is how a short stimulus leads to such a long-lasting activation of the TRP receptor."