Neuroscientists at the Massachusetts Institute of Technology have identified the cells where memory traces are stored in the mouse hippocampus. In a study published recently, they reported to establish a population of cells in the dentate gyrus of the mouse hippocampus that encoded a particular context and were able to generate a false memory and study its neural and behavioral interactions with true memories. The researchers optogenetically activated the memory engram bearing cells in the hippocampus and these activated engrams were used to implant false memories in the mice’s brains.
It was demonstrated that the optogenetic reactivation of memory engram bearing cells was not only sufficient for the behavioral recall of that memory, but could also serve as a conditioned stimulus for the formation of an associative memory. The MIT team is now planning further studies of how memories can be distorted in the brain.
Ramirez S, Liu X, Lin PA, Suh J, Pignatelli M, Redondo RL, Ryan TJ, & Tonegawa S (2013). Creating a false memory in the hippocampus. Science (New York, N.Y.), 341 (6144), 387-91 PMID: 23888038