Creation of artificial associative memory through engram cell ensembles

Noriaki Ohkawa, Kaoru Inokuchi

Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama

Memory is stored in the brain as an ensemble of cells activated during learning, and it is called as engram cell ensemble. Although optical stimulation of a cell ensemble triggers the retrieval of the corresponding memory, it is unclear how the association of information occurs at the cell ensemble level. Using optogenetic stimulation, we found that an artificial association between stored, non-related contextual and fear information was generated through the synchronous activation of distinct engram cell ensembles corresponding to the stored information. This mechanism may underlie memory updating by pre-existing networks to form qualitatively new memories.

Address correspondence to Dr. Noriaki Ohkawa, Department of Biochemistry, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama (2630 Sugitani, Toyama 930-0194, Japan)