Researchers at the Massachusetts Institute of Technology (MIT) have found that shedding a little light on amnesia can bring about the recall of lost memories. Using optogenetics, a technology that controls brain activity with light, researchers were able to reactivate memories in mice.
The study follows a longtime debate in the neuroscience community that questions whether retrograde amnesia points to lost memories becoming inaccessible due to damage of specific brain cells or if something blocks access to the lost memories. The results of the study disproved what the majority of neuroscientists had previously thought. While most had favored the storage theory, “Amnesia is a problem of retrieval impairment,” related Susumu Tonegawa, MIT Professor.
MIT Researchers gave some of the mice in their study a chemical called anisomycin that induced retrograde amnesia, a memory disorder that follows traumatic brain injury, stress or diseases such as Alzheimer’s. A control group of mice were given saline. Business Standard reports May 29 that each of the mice had been trained to associate a small shock in their feet with a specific chamber, that even when they were not shocked, induced a reaction of freezing when they had entered into the same environment. Mice that had been given the chemical didn’t freeze when they had entered into the chamber.
The next part of the study placed the mice in a neutral environment that used a sort of mapping system via blue light pulses that activated brain cells as they had been in the first part of the study. Mice who had forgotten began freezing again. As the Washington Post points out, the results show that “‘lost’ memories lurk in the brain waiting to be found again,” -- at least in mice.
The study was published in the journal Science May 29. While hopes have been raised over the possibilities of memory retrieval for those who have suffered severe memory loss, the current implementation of the treatment is considered unethical due to its invasive nature, writes Wall Street OTC. The results of the memory retrieval study are, however, significant next steps in developing memory recall treatments for humans.