Contacts:
Sarah Goodwin

Kathi Ovnic
Holly Korschun
SEPTEMBER 2, 1999
PROTEIN TEAMWORK IS NECESSARY FOR BRAIN PROCESSES INVOLVING MEMORY AND LEARNING

According to recent findings by Emory University scientists, memory and learning are dependent upon the collaboration of specific proteins in the brain that are separated by the small gap between communicating neurons.

In research reported in the Aug. 27, 1999 issue of Science, Emory pharmacologist Raymond J. Dingledine, Ph.D., and his colleagues studied "synaptic plasticity" of neurons in the hippocampus ­ the region of the brain involved in memory storage. Because synaptic connections within the nervous system are "plastic," they can change their strength or they can increase or decrease in number depending on circumstances. Experience can mold the nervous system by stimulating or repressing electrical activity and can exert a lasting influence on subsequent patterns of behavior leading to long-term memory.

The Emory group found that a well-known form of synaptic plasticity called long-term depression (LTD) occurs when presynaptic and postsynaptic receptor proteins are activated jointly.

"The cellular mechanisms underlying activity-induced changes in the strength of communication between neurons ("synaptic plasticity") have been the subject of intense study for the past 25 years," says Dr. Dingledine, "and a heated controversy has developed over whether the key changes occur on the presynaptic or postsynaptic membrane. Our data indicate that for one common type of plasticity, essential events leading to plasticity must occur on both sides of the synapse."

Identification of the proteins responsible for synaptic plasticity provides new leads for developing drugs that improve memory, and perhaps also drugs that can relieve forms of chronic pain that also depend on changes in the strength of brain pathways.

The Emory research was supported by the National Institutes of Health, the American Epilepsy Society and Sigma Xi.

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