The flow of copper in the brain has a previously unrecognized role in cell death, learning and memory, according to research at Washington University School of Medicine in St. Louis. The researchers' findings suggest that copper and its transporter, a protein called Atp7a, are vital to human thinking. They speculate that variations in the genes coding for Atp7a, as well as other proteins of copper homeostasis, could partially account for differences in thinking among individuals.
Using rat and mouse nerve cells to study the role of copper in the brain, the researchers found that the Atp7a protein shuttles copper to neural synapses, the junctions that allow nerves to talk to one another.
At synapses, the metal ions affect important components responsible for making neural connections stronger or weaker. The changing strength of neural connections -- called synaptic plasticity -- accounts for, among other things, our ability to remember and learn.
"Why don't we think a hundred times better than we do?" asks senior author Jonathan Gitlin, M.D., the Helene B. Roberson Professor of Pediatrics at Washington University School of Medicine. "One answer to that question is, perhaps we could -- if the brain could make the right connections. We've found that copper modulates very critical events within the central nervous system that influence how well we think."
The research was led by neuroscience graduate students Michelle Schlief, Ph.D., and Tim West, Ph.D., in collaboration with Anne Marie Craig, Ph.D., and David M. Holtzman, M.D., the Andrew B. and Gretchen P. Jones Professor and head of the Department of Neurology and appears online this week in the Proceedings of the National Academy of Sciences.
The researchers found that when a chemical signal, or neurotransmitter, hits one of the microscopic antennas present at nerve synapses, Atp7a reacts and quickly brings copper ions from their storage areas within nerve cells to the cell surface.
Contact: Gwen Ericson
Washington University School of Medicine