Researchers Demonstrate How to Erase and Restore Memories

In a recent study conducted by researchers at the University of California, San Diego School of Medicine, scientists were able to erase and reactivate memories in rats, altering the animals’ reaction to past events. By stimulating nerves in the brain at frequencies that are known to weaken and strengthen the connections between nerve cells, scientists were able to selectively remove a memory and predictably reactivate it. Scientists optically stimulated a group of nerves in a rat’s brain that had been genetically modified to make them sensitive to light, and simultaneously delivered an electrical shock to the animal’s foot. The rats learned to associate the optical nerve stimulation with pain, displaying fear behaviors. In the next stage of the study, 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. The rats subsequently no longer responded to the original nerve stimulation with fear, suggesting the pain-association memory had been erased. To read more about this study, click here.