Researchers at the University of California, Los Angeles (UCLA) suggest that recovering lost or forgotten memories is possible.
Losing memory can be scary but many people, such as the ones who are suffering from Alzheimer's disease, can lose memory.
David Glanzman, professor of integrative biology and physiology at UCLA, who is also the lead author of the study, reveals that memories are not stored in synapses, or the connection between neurons.
The new study shows that synapses are the regions that are damaged when a person is suffering from Alzheimer's disease.
Glanzman explains that the human nervous system can regenerate broken or lost synaptic connections. If synaptic connections are restored, then it can help a person retain memory.
The study involved examination of Aplysia, which is a marine snail. The researchers focused mainly on the defensive response mechanism of the snail. The snail was also given mild electric shocks to its tail to enhance the snail's withdrawal reflex.
The study found that the electric shocks caused the snail to release a hormone called serotonin in the snail's central nervous system. Previous studies have suggested that serotonin lays the base for the growth of fresh synaptic connections that also result in the creation of long-term memory.
The brain makes new proteins that are responsible for creating new synapses when long-term memories are formed. In case the process is disrupted, new long-term memories will not form at all.
"If you can restore the synaptic connections, the memory will come back. It won't be easy, but I believe it's possible," said Glanzman.
The researchers believe that memories are not actually stored in synapses but held somewhere else. Glanzman and his team posit that memories are stored in the nucleus of neurons, but they have not proved it yet.
Thousands of people suffer from Alzheimer's disease worldwide. In 2013, there were over 5 million Americans who had Alzheimer's disease, the most common form of dementia. The number of Alzheimer's patients in the U.S. is estimated to triple by 2050.
Glanzman suggests that the latest research has important implications for patients suffering with Alzheimer's disease. Even as the disease destroys the synapses, it does not mean it destroys the memories.
"As long as the neurons are still alive, the memory will still be there, which means you may be able to recover some of the lost memories in the early stages of Alzheimer's," added Glanzman.
The study also reveals that neurons die in the later stage of Alzheimer's, which means that memories of patients at that stage cannot be recovered.