How are memories saved? Where does the recording take place and how?
—Michael Saayman, Cape Town, South Africa

Michael Rugg, director of the Center for the Neurobiology of Learning and Memory at the University of California, Irvine, provides an explanation:

Understanding exactly how the brain encodes and stores memories is one of the central, unsolved mysteries in neuroscience. Currently the most widely accepted theory is long-term potentiation (LTP)—the lasting communication established between two neurons when they are stimulated simultaneously.

As a person processes an event, two neurons pass information through a small space called a synapse. This chemical conversation triggers an intricate cascade, inviting nearby neurons to fire and ultimately creating a network of connections with varying strengths. Afterward, this pattern of connections, or memory, remains within the network of neurons that processed the event.

Although many areas of the brain contain synapses capable of creating strong patterns of connectivity, the hippocampus is a particularly favorable spot for recording memories. This brain region plays a critical role in learning new information, forming spatial memories and storing short-term memories as long-term ones.

Memories formed with the hippo­campus are especially rich because they integrate input from several areas of the brain, and the ­hippocampus contains densely packed layers of neurons. In addition, damage to this region and nearby areas causes profound and perm­anent amnesia—an inability to store new memories or to recall old ones—and is observed in patients who have Alz­heimer’s disease.

2 Comments

1. 1. H2Ov 09:11 PM 12/28/09

   I was looking for something new and insightful maybe "science" identifies possible memory code between the hydrophilic heads and the hydrophobic tails of Phospholipids in neuron cell membranes ? Or, calcium channel waves generated by neuroglia astrocytes may help record memory codes? If you follow up on this, Please cite H2Ov for suggesting the hypothesis.

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2. 2. Macrocompassion 10:53 AM 1/5/10

   At a higher level of memory retention I suggest that the memories are continuously being reviewed and then stored again (posibly in a fresh part of the brain).
   
   In my experience, things that are easy to remember are treated in this way more often and things of less importance are forgotten due to low revision frequency or use. I think this is related to repeating dreams too. Occasional somebody else reminds us of one of these little-used memories and in my case at least I often then remember it, but not always
   
   The Altzheimer's sufferer's problem also is relevant here where old memories are not forgotten whist short-term memory can be easily lost.

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