(Medical Xpress) — College and cramming often wheres theres one, the other is not far behind. That said, however, it has been recognized since the late 1800s that repeated periodic exposure to the same material leads to better retention than does a single en masse session. Nevertheless, the phenomenons neurobiological processes have remained poorly understood, although activity-dependent synaptic plasticity notably long-term potentiation (LTP) of glutamatergic transmission is believed to enable rapid storage of new information. Recently, researchers at the University of California in Irvine and the Scripps Research Institute in Jupiter, Florida determined that hippocampal activity can enhance LTP through theta burst stimulation (TBS) but only when the affected synapses receive, after a long delay, a secondary TBS. The researchers describe mechanisms that maximize synaptic changes that optimally encode new memory by requiring long delays learning-related TBS activity.