DURHAM, N.C. -- During learning and memory formation, the brain builds or remodels tiny structures on the surface of its nerve cells to store the new information. Now, a team led by Duke University Medical Center researchers has discovered where the brain gets the raw materials for such construction -- and has even taken "home movies" of the process.
The discovery, made in rodents, may lead to advances in understanding Alzheimers disease, autism and age-related memory loss, and could point to potential treatments for these and other neurological conditions, said senior study investigator Michael Ehlers, M.D., Ph.D., an associate professor of neurobiology and a Howard Hughes Medical Institute investigator at Duke.
The researchers published the findings in the Dec. 7, 2006, issue of the journal Neuron.
The research was funded by the National Institutes of Health, the American Health Assistance Foundation and the Raymond and Beverley Sackler Foundation.
The team focused on specific structures in brain nerve cells, or neurons, called dendritic spines. These are tiny bumps that form on the surface of dendrites, which extend off neurons like tree branches and receive chemical signals from other neurons. Each dendritic spine "talks" with its counterpart on a nearby neuron, and collectively the two structures comprise the "synapse" that links the neurons.
The brain stores new information by changing the structure of the synapses, Ehlers said. If we need to remember a name, directions to a location or how to perform certain motor tasks -- anything involving learning or memory, really -- our brain does it by changing the properties of synapses, he said.
During learning, synapses change in ways that make it easier for connected neurons to communicate with each other. This plasticity can occur in two ways. One way is structural, in which a synapse changes in size or shape; the other way is functional, in which conne
Contact: Marla Vacek Broadfoot
Duke University Medical Center