Adult brain contains millions of silent synapses: Study

The adult brain contains millions of 'silent synapses,' which are immature connections between neurons that remain inactive until they are recruited to help form new memories, according to MIT neuroscientists.

Until now, it was thought that silent synapses existed only during early development when they assisted the brain in learning new information. However, a new MIT study found that approximately 30 per cent of all synapses in the cortex of adult mice 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 said. Mark Harnett, an associate professor of brain and cognitive sciences, is the senior author of the paper, which appears today in Nature. Kwanghun Chung, an associate professor of chemical engineering at MIT, is also an author.