In an effort to understand how brain cells exchange chemical messages, scientists say they have successfully used a highly specialized microscope to capture more precise details of how one of the most common signaling molecules, glutamate, opens a channel and allows a flood of charged particles to enter. The finding, which resulted from a study led by Johns Hopkins Medicine researchers, could advance the development of new drugs that block or open such signaling channels to treat conditions as varied as epilepsy and some intellectual disorders.
A report on the experiments, funded by the National Institutes of Health and in collaboration with scientists at UTHealth Houston, was published March 26 in the journal Nature.
Neurons are the cellular foundation of the brain, and the ability to experience our environment and learn depends on [chemical] communications between neurons."
Edward Twomey, Ph.D., assistant professor of biophysics and biophysical chemistry at the Johns Hopkins University School of Medicine
Scientists have long known that a major molecule responsible for neuron-to-neuron communications is the neurotransmitter glutamate, a molecule abundant in the spaces between neurons. Its landing place on neurons is a channel called an AMPA receptor, which interacts with glutamate, and then acts like a pore that takes in charged particles. The ebb and flow of charged particles creates electrical signals that form communications between neurons.
To figure out details of the miniscule movements of AMPA receptors (at the level of single atoms), researchers used a very high-powered microscope to image these channels during specific steps in the communications processes. For the study, the scientists used a cryo-electron microscope (cryo-EM) in a facility at the Johns Hopkins University School of Medicine.
