A new study gives scientists hope that they can bring back the lost memories of Alzheimer patients.
Researchers at the University of California, San Diego School of Medicine have been able to erase and then bring back the memories of rats. They were able to do this by stimulating nerves in the brain at different frequencies that weaken and then strengthen connections between synapses. Although right now scientists have only tested this technique out on rodents, they are hopeful that it will be just as successful with humans.
“We can form a memory, erase that memory and we can reactivate it, at will, by applying a stimulus that selectively strengthens or weakens synaptic connection,” said the senior author of the study Roberto Malinow.
“Since our work shows we can reverse the processes that weaken synapses, we could potentially counteract some of the beta amyloid’s effects in Alzheimer’s patients,” Malinow, who is also a professor of neurosciences, continued.
In order to know that memories were being erased from the rats, the researchers first had to create certain memories. The researchers optically stimulated a group of nerve cells in the rats’ brains that had been genetically modified to react to light. Evey time these nerve cells were stimulated, the rats would simultaneously receive an electrical shock to their feet.
Soon, the rats associated the nerve stimulation with pain, and would react in a frightened way when the nerve cells were optically stimulated.
After the rats had the memory of pain successfully implanted into them, they were then exposed to low-frequency optical pulses that erased their memories. The rats were then subjected to the optical stimulation of the modified group of nerve cells again. However, instead of reacting with pain or fear, the rats did not show any sort of emotion at all, indicating their memories were gone.
The researchers found that by giving the rats high-frequency optical pulses to the same area, the rats would regain their memories. Afterwards, the rats would once again respond to stimulation by showing pain and fear, even though they had not had their feet re-shocked.
The study seems to prove that memories can be recreated. In the case of patients with dementia or Alzheimer’s disease, it could give a new hope that their memories can be restored.