It is a century-old belief that memory—information storage in the brain—is realized by means of changes in synaptic strength. For instance, high-frequency stimulation of an excitatory pathway in the hippocampus and several other regions has been shown to give rise to the strengthening of signal transmission and, hence, the synaptic connection. A persistent increase (or decrease) in synaptic strength is referred to as long-term potentiation (or depression).

Short-term plasticity (STP), on the other hand, has to do with "temporary," fast, and activity-dependent modulation of synaptic function.