Collectively, these results suggest that early-phase potentiation is accompanied by a rapid increase in sites for the assembly of Folinic acid calcium salt pentahydrate puncta of synaptic proteins and presynaptic structures, which may represent initial steps in the formation of new stable synapses during late-phase potentiation. The increase in sites is initiated almost immediately after the induction of potentiation, and thus can contribute to the transition between the early and late phase mechanisms of plasticity. More specifically, the new sites may serve as seeds for the formation and maintenance of new synapses, thereby acting as local “tags” for protein and RNA synthesisdependent synaptic growth during late-phase plasticity. Consistent with that idea, actin polymerization, which is important for rapid changes in synaptic puncta and structures, is also important for synaptic tagging. Tagging is usually thought to contribute to the long-term Ginsenoside-F2 strengthening of existing synapses, but our results suggest that it can contribute to de novo synapse formation during the late phase as well. When the new puncta and structures become functional and whether they might also contribute to early-phase potentiation remains to be determined. Other studies have suggested that the formation of new functional synapses can take from as little as 30 min to more than 15 hrs. Potentiation and the increase in puncta have similar time courses and pharmacological profiles, new puncta of pre- and postsynaptic proteins colocalize, and the new presynaptic puncta undergo vesicle cycling, suggesting that the puncta could become functional during early phase potentiation. If so, the rapid assembly of puncta of pre- and postsynaptic proteins suggests a new basis for pre- and postsynaptic “unsilencing” of synapses during early LTP. The rapid increase in sites where puncta may form also suggests a new type of structural mechanism that has not generally been considered for early LTP. We found that the puncta and structures are very dynamic. Most of them continually assemble and disassemble on a time scale of minutes, although a subset of puncta and structures are more stable, and new puncta and structures assemble within minutes after the induction of potentiation. Previous studies of synaptic development have similarly found that some while others are more stable, on a time scale ranging from minutes to days or weeks.