Keeping the Memories Alive


You are here

Are our memories recorded in a one-time physical change, like writing permanently on a clay tablet? Prof. Yadin Dudai, Head of the Weizmann Institute's Neurobiology Department, and his colleagues recently discovered that the process of storing long-term memories is highly dynamic, sustained by a molecular machine that must run constantly. They showed that stopping the machine even briefly can erase some types of long-term memories. These findings, which appeared recently in Science, may pave the way to future treatments for memory problems.
Dudai and research student Reut Shema, together with Todd Sacktor of the SUNY Downstate Medical Center, trained rats to avoid certain tastes. They then injected a drug to block a specific protein into the taste cortex – an area of the brain associated with taste memory. They believe that this protein acts as a miniature "machine" that keeps memory running by actively maintaining physical, learning-induced changes in the synapses – the conduits for signals between nerves. The scientists reasoned that blocking the protein would reverse those changes. Regardless of the taste the rats were trained to avoid, they forgot their learned aversion after a single application of the drug into the brain, and the signs so far indicate that the unpleasant memories of the taste had indeed disappeared. This is the first time that memories were shown to be susceptible to erasure long after their formation.
"This drug is a molecular version of jamming the operation of the machine," says Dudai. "When the machine stops, the memories stop." These findings raise the possibility of developing future, drug-based approaches for boosting and stabilizing memory.
Prof. Yadin Dudai's research is supported by the Norman and Helen Asher Center for Brain Imaging; the Nella and Leon Benoziyo Center for Neurological Diseases; the Carl and Micaela Einhorn-Dominic Brain Research Institute; the Irwin Green Alzheimer's Research Fund; and the Sylvia and Martin Snow Charitable Foundation. Prof. Dudai is the incumbent of the Sara and Michael Sela Professorial Chair of Neurobiology.