Dissecting the components of long-term potentiation.

The formation of memories relies in part on plastic changes at synapses between neurons. Although the mechanisms of synaptic plasticity have been studied extensively over several decades, many aspects of this process remain controversial. The cellular locus of expression of long-term potentiation (LTP), a major form of synaptic plasticity, is one of the most important unresolved phenomena. In this article, some recent advances in this area made possible by the development of new imaging tools are summarized. These studies have demonstrated that LTP is compound in nature and consists of both presynaptic and postsynaptic components. Some features of presynaptic and postsynaptic changes during compound LTP are also reviewed.