Аннотация:The advent of neuromorphic technologies brings new tasks for the AIorientedneuroscience research. Our work explores neurobiologicalprinciples of memory encoding that can vastly surpass capabilities ofexisting neuromorphic hardware. In the first place, neurobiological memoryis very selective in respect to number of neurons involved. Here we studiedthis selectivity in a model of associative memory formation in mice.Typically, associative conditioning uses reinforcement deliveredimmediately after a new cue. However, this does not allow to separateneuronal mechanism for cue memory encoding from processes of itsassociation with reinforcement. In the present work we used the contextpreexposure facilitation effect paradigm (Fanselow, 1990; Rudy andO'Reilly 2001) to study allocation of associative memory into the neuronsof previously established contextual memory. Mice were first allowed toexplore a new context A for 5 min and following a 3-day delay received a 2sec footshock immediately after being replaced in this context. Resultingcontextual fear persisted for at least 30 days after this engram conditioningand was specific for the context A, it did not develop if immediate shockwas delivered in a context B and there was no freezing in a novel context C.We next studied how this association is allocated in the mouse brainneuronal circuits. For this we used activity-inducible transcription factor c-Fos as a cellular marker of memory allocation during conditioning.Furthermore, we combined this c-Fos neuroimaging with c-Fos TRAP(Targeted Recombination in Active Populations; Guenthner et al., 2013)technique to reveal overlap in cellular populations involved in the initialacquisition of contextual engram and its later associative conditioning. Ourdata suggest that only a limited population of neurons in the mouseassociative neocortex, mainly pyramidal neurons, are involved in thecontextual engram. Furthermore, it is in this selective ensemble of neuronsthe subsequent associative memory for negative reinforcement is allocated.We discuss this data in respect to principles of neuromorphic associativememory encoding. Supported by RSCF 14-15-00685, RFBR 17-00-00215.