Nail Burnashev (Max-Planck Institute for Medical Research, Heidelberg, Germany): "In our brain the influx of calcium ions into neurons is an exquisitely controlled event, because calcium entry is important for learning and memory functions and, if excessive, can lead to cell death. One way for the controlled entry of calcium into neurons is through ion channels activated by the abundant excitatory neurotransmitter glutamate. Molecular studies of these channels conducted over the past three years have helped delineate those channel elements that determine the glutamate-evoked calcium flux into neurons.
"Glutamate receptor channels are composed of several different subunit constituents. The subunits for a ubiquitous glutamate receptor carry in a particular position either a positively charged amino acid (arginine) or a neutral amino acid (glutamine). These amino acids affect the properties of ion flow through the channel (T.A. Verdoomm, et al., Science, 252:1715, 1991; R.I. Hume, et al., Science, 253:1028, 1991). The ...
