Each time a memory is retrieved, the brain updates this memory and, for a short period of time, it becomes vulnerable. This process of reconsolidation and the participating areas of the brain were investigated by a team of scientists at Bochum's Ruhr University. Using optogenetics, a method combining optics and genetics, they were able to influence the ability to remember. Their findings offer promising new approaches for the therapy of anxiety disorders. The researchers' insights were published in the journal "Cerebral Cortex".
Reconsolidation suppressed with optogenetics
Our memories are not, as one might think, stored unchangeably in our brains. Particularly when memories are retrieved, they become vulnerable. The brain then attempts to update our memory using current information. The research teams of Prof. Dr. Magdalena Sauvage and Dr. Vanessa Lux, as well as Prof. Dr. Stefan Herlitze and Dr. Olivia Masseck have succeeded in altering this phase of reconsolidation with the help of optogenetics. Using state of the art high resolution imaging techniques, they observed how this affects our ability to memorise. With optogenetics neuroscientists control genetically modified cells with light. With extremely high temporal and spatial precision, they are able to "turn off" neuronal activity at precisely the moment when reconsolidation begins.
Research offers new approaches for anxiety therapy
The scientists' findings show that a whole network of brain areas is active during reconsolidation. A key role within this network is played by the Corno Ammonis 1 region in the hippocampus. This area in the medial temporal lobe becomes active every time a memory is retrieved. When neuronal activity in this area of the brain is deactivated optogenetically during the phase of reconsolidation, severe memory impairments are observed. Using this technique in a rodent model, the scientists have successfully "deleted" fearful memories. "Our results have shed light on new brain targets for the study of reconsolidation and the retrieval of fear memory. These insights could offer promising new approaches for the treatment of posttraumatic stress disorders and other similar illnesses," explains Dr. Vanessa Lux.
The findings are the results of a cooperation between two projects of Collaborative Research Center 874 at the Ruhr University. The interdisciplinary research group has been funded by the Deutsche Forschungsgemeinschaft since 2010 to investigate sensory processing in the brain. Further funding for the project was granted by the Mercator Research Group "Structure of Memory" and the International Graduate School of Neuroscience.
Citation: Lux V, Masseck OA, Herlitze S, Sauvage MM (2015) Optogenetic Destabilization of the Memory Trace in CA1: Insights into Reconsolidation and Retrieval Processes. Cereb. Cortex doi: 10.1093/cercor/bhv282.
Text: Annegret Kalus