Funding for this site is provided by readers like you.
Memory and the brain

Forgetting and Amnesia




The kind of long-term depression that we are talking about here is not the depressed psychological state that immediately comes to mind when you hear this expression. Rather, we are talking about a molecular process by which the brain’s neurons can reduce the efficiency of the connections between them.

Long-term depression is, in a sense, the opposite of long-term potentiation, the process by which synaptic connections are strengthened in order to store new information in memory.

Because the neurons of the brain’s two hippocampi, through which newly memorized facts enter, cannot keep strengthening their synapses indefinitely.

Scientists believe that one possible role of long-term depression might be to bring the strengthened synapses back to their baseline level– resetting them to zero, so to speak, and thus erasing old memories so that new ones can be stored in their place.

If these memory traces have had enough time to be transferred from the hippocampus to other circuits of the brain, they will probably be retained for a long time. Otherwise, they will be forgotten, as a result of the process of long-term depression.

Just like long-term potentiation, long-term depression is based on movements of calcium ions, but triggered in this case by a particular pattern of stimulation.


  Presentations | Credits | Contact | Copyleft