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University of Iowa News Release

July 30, 2003

UI Scientist Provides New Image Of Zinc In The Brain

Although more people likely would associate the word "metal" with rock music than with the brain, scientists know that the brain needs zinc and other metals to function properly. Even though the role of metals within proteins is well understood, the question of why synapses -- the cellular devices that convey information from one nerve cell to the next -- contain high concentrations of zinc remains a mystery.

In the cover story of the July 30 issue of The Journal of Neuroscience, Alan Kay, associate professor of biological sciences in the University of Iowa College of Liberal Arts and Sciences, takes a significant step toward understanding the role of zinc in the brain.

Kay's work contests the results of two papers that were published back-to-back in the prominent scientific journal Nature in 1984, which suggested that zinc is released during the course of synaptic transmission and acts like a neurotransmitter.

Kay says, "For almost 20 years this hypothesis survived unchallenged within the scientific literature. I think that its persistence can be attributed both to its eminent plausibility and the absence of the vigorous scrutiny that is necessary for the progress of science."

Using a molecule that fluoresces when it binds to zinc, Kay was able to visualize the metal in live slices of rat brain. This technique allowed him to monitor how both the location and the concentration of zinc varied while the slices were activated. He says that contrary to the dogma, not much -- if any -- zinc was released when neurons were activated, although the tiny vesicles that contain neurotransmitters do indeed have high concentrations of zinc.

Precisely what zinc is doing in nerve endings remains a mystery. For his part, Kay believes that he may have chanced upon a novel mechanism for relaying information between neurons. Since zinc has been implicated in a number of brain diseases, an understanding of the normal role of zinc in the brain may encourage the development of treatments for maladies ranging from Alzheimer's disease to stroke.

STORY SOURCE: University of Iowa News Services, 300 Plaza Centre One, Suite 371, Iowa City, Iowa 52242-2500.

CONTACTS: Gary Galluzzo, 319-384-0009, gary-galluzzo@uiowa.edu.