“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 connections,” study senior researcher Dr. Roberto Malinow, a professor of neurosciences said in a university press release.
The neuroscientists’ findings may hold big potential for the treatment of such diseases as Alzheimer’s and post-traumatic stress disorder (PTSD).
The researchers used light pulses that they had previously studied and proved to have an effect on the connections in parts of the brain. By targeting these pulses at small, select portions of the brain they were able to manipulate memory and some emotions.
Analyses showed chemical changes within the optically stimulated nerve synapses, indicative of synaptic strengthening.
In the next stage of the experiment, the research team demonstrated the ability to weaken this circuitry by stimulating the same nerves with a memory-erasing, low-frequency train of optical pulses. These rats subsequently no longer responded to the original nerve stimulation with fear, suggesting the pain-association memory had been erased.
The work’s most striking finding though was the lost memories could be restored by the re-stimulation of the same nerves with memory-forming, high-frequency pulses. Such re-conditioned rodents yet again responded with fear to the stimulation. And that is while they had not had their feet shocked this time.
The implications on this are significant as it could lead to new treatments for mental illness and degeneration. While it’s unlikely we will see human testing for some time it could open up an entirely new way to repair minds damaged by time or trauma. Many are already speculating that this could lead to a cure for Alzheimer’s disease. Others are somewhat concerned about the capability of destroying memories as well.