A new theory on where memory is stored in the brain suggests that lost memories could possibly be restored. If true, it could radically change almost everything that scientists know about memory loss and even lead to a better treatment to Alzheimer’s disease.
The theory, proposed by Dr. David Glanzman of the University of California, Los Angeles, claims that the brain does not store long-term memory in the synapses. This idea runs contrary to the established consensus that the center of memory formation and storage is within the synapse.
Since synapses, the connections between neurons, are among the first parts of the brain for Alzheimer’s to attack, scientists assumed the resulting memory loss was due to their death. But if memories actually reside somewhere else in the brain, then the cause for memory loss must be different.
Glanzman and his team were studying the aplysia, which is a sea snail that has easily observable neurons and synapses not very different from those in humans. In the aplysia neurons the researchers found that long-term memory depended on the formation of new synaptic connections, caused by the release of serotonin. Even more remarkable: memories that had seemed lost actually returned, without any obvious correlation to synapse regeneration.
Since the regained memories did not coincide with reconnected synapses, the researchers concluded that the synapses were not where the aplysia stored memory in the first place. “We think it’s in the nucleus of the neurons. We haven’t proved that, though,” Glanzman said.
If this is true in the human brain, it means that even after Alzheimer’s destroys a person’s synapses, the memories seemingly lost may still exist within the neurons themselves. Theoretically, those memories could be restored, at least until neuron death, when Glanzman postulates that memory restoration is impossible.