Forgotten But Not Gone: How The Brain Re-learns

Scientists at the Max Planck Institute of Neurobiology have been able to show that new cell contacts established during a learning process stay put, even when they are no longer required. The reactivation of this temporarily inactivated "stock of contacts" enables a faster learning of things forgotten. To learn something, nerve cells make new connections with each other.  Whenever a special point of contact, called synapse, forms at the end of the appendage, information can be transferred from one cell to the next - and new information is learned. Once the contact breaks down, we forget what we have learned. Everything seems to point to the fact that when we forget, synapses are only disabled, but not physically removed. Many of the appendages that develop between nerve cells are thus maintained and facilitate later relearning. This insight is crucial to our understanding of the fundamental processes of learning and memory.