A group of researchers with the help of the National Institutes of Health’s National Institute of Mental Health (NIMH) successfully developed a method to determine which cellular components hold specific memory in genetically-engineered mice. To do so, genetic tags that trace memory-sustaining proteins were used.

Mark Mayford and Naoki Matsuo from the Scripps Research Institute employed the amygdala, traceable neurons which glow red when animals learn fear, and green when that specific memory is retrieved. With these in the mice's brain's fear center, proteins involved in collecting memory can be tracked.

Results of this process called fear conditioning led researchers to believe that proteins known as AMPA receptors "strengthen memories by becoming part of the synapses encoding them." With that said, further genetic engineering was initiated, this time to locate the synapses where stronger memory can be established.

Using AMPA receptors, fear conditioning went differently than in the case of the amygdala. Proteins that were supposed to build memory were suppressed, so the receptors had enough time to find the synapses and encode memory there. A few hours passed, then the AMPA emitted green glow as sign that destinations were reached.

For more details on the study, click on the via link below.