Scientists have identified a novel mechanism behind the decrease in strength of synapses in the brain, a process that leads to the creation of memories and their long-term storage.
The increase or decrease in strength among synapses, and subsequent changes in memory, are based on sensory-driven experiences. Synaptic strengthening or weakening also occurs during the brain's development. Synapses are the connections between neurons, or nerve cells.
Reporting in today's Science, researchers from the Howard Hughes Medical Institute (HHMI) and Brown University describe machinery at the synapse for the synthesis of new proteins that depress synaptic strength. The study was conducted in rats.
The finding suggests that experience or activity in the mammalian brain can regulate individual synapses, said lead investigator Kimberly Huber, a post-doctoral researcher at Brown.
"The study shows that synaptic depression actually relies on the manufacture of proteins at the synapses," she said. "This is the first demonstration in mammals that when synapses change, the modification depends on new proteins created specifically at the site."
This synaptic chemical activity is an efficient way for the brain to make new proteins and change existing ones rapidly, Huber said. "The mechanism appears to be a viable way for the brain to express its changes. We think this activity also may be a way that the structure, or shape, of synapses can be altered."
The findings hint that connections in the brain can be modified on an individual basis, facilitating long-term memory storage.
"It is important to understand the mechanism by which connections are weakened, not only
because such understandin
'"/>
Contact: Scott Turner
Scott_Turner@Brown.edu
401-863-1862
Brown University
18-May-2000