The “silent synapses” in adult brains, according to MIT

I found a ScienceDaily article discussing MIT research into adult brains and how they contain “millions of ‘silent synapses’” which remain dormant until they start forming new memories and that’s when they start connecting:

Researchers say this hidden pool of synapses may explain how the brain continues to learn throughout life without disrupting existing memories.

“These silent synapses are looking for new connections, and when important new information is presented, connections between the relevant neurons are strengthened. This lets the brain create new memories without overwriting the important memories stored in mature synapses, which are harder to change,” says Dimitra Vardalaki, an MIT graduate student and the lead author of the study.