MIT neuroscientists have discovered that the adult brain contains millions of “silent synapses” — immature connections between neurons that remain inactive until they’re recruited to help form new memories.
Until now, it was believed that silent synapses were present only during early development, when they help the brain learn the new information that it’s exposed to early in life. However, the new MIT study revealed that in adult mice, about 30 percent of all synapses in the brain’s cortex are silent.
The existence of these silent synapses may help to explain how the adult brain is able to continually form new memories and learn new things without having to modify existing conventional synapses, the researchers say.
“These silent synapses are looking for new connections, and when important new information is presented, connections between the relevant neurons are strengthened….