http://www.eetimes.com/story/technology/OEG20011217S0047
Using a fluorescent marker, the researchers were able to show how short- and long-term memories result from different physical effects in the brain. Short-term memories, it turns out, result from the instant assembly of more filaments to strengthen the skin of the cell temporarily, whereas long-term memories result from the growing of a new synapses to strengthen the connection permanently.