Synapses, the junctions where signals pass between nerve cells, are crucial to thought and behavior. Plasticity, synaptic reorganization throughout life, underlies learning and memory. School of Medicine scientists have discovered that SynCAM 1, an “adhesion molecule” that spans synapses, is essential for synapse formation during development and maintenance in adulthood.
In the December 9 issue of Neuron, Thomas Biederer, Ph.D., associate professor of molecular biophysics and biochemistry, and colleagues describe mice in which the SynCAM 1 gene could be switched on and off at will. More synapses formed during development when SynCAM 1 was overexpressed, and the molecule was required to maintain synapses in adults. But mice lacking SynCAM 1 showed enhanced plasticity, performing better on spatial learning tests than mice overexpressing it.
“Some SynCAM 1 is needed to promote contact,” Biederer says, “but too much glues down the synapse and inhibits its function. These findings provide new molecular insight into synaptic aberrations underlying developmental brain disorders such as autism.”