Scientists from Harvard University and Washington University in St. Louis describe the findings in the July 23 issue of the journal Cell.
"This is very basic work, far from any clinical applications at this point," says author Joshua R. Sanes, professor of molecular and cellular biology in Harvard's Faculty of Arts and Sciences. "Still, one can think of lots of cases, from normal aging to mental retardation to neurodegenerative disease, where making more synapses or preventing synapse loss might be beneficial. This finding may eventually point the way to new therapies."
The work, using mice as a model, was conducted while Sanes and co-author Hisashi Umemori were at Washington University.
Synapses are the sites where neurons communicate with each other to form the large and complex information-processing networks of the brain. These networks are highly modifiable because the synapses between neurons are plastic, leading to changes that underlie learning. Synapses are also the targets of nearly all psychoactive drugs, including both prescription medications and illicit drugs.
"We knew that the apparatus for sending and receiving chemical and electrical signals was concentrated at the synapses where neurons connect with each other," Sanes says. "We wanted to determine how these special sites form."
As the early nervous system develops into a dense tangle of neurons, synapses sprout at places where neurons grow close to one another. In order for a synapse to actually form, Sanes and Umemori believed, certain key molecules would have to flow across the gap between two neurons to commence development of a synapse lin
Contact: Steve Bradt