Based on these results, Lashley concluded that the putative memory engram cells are not localized in the cerebral cortex, leading him to formulate the Mass Action Principle (Lashley, 1950). As discussed below, Lashley’s notion that engram cells for a specific memory are spread broadly and ...
Here, this system was used to label cFos-positive engram cells in the dentate gyrus (DG) at encoding of contextual fear memories, during which DOX was removed from the animals’ diet. 1 day after encoding, fear memories were recalled by context exposure, and the engram cells’ (EYFP+) ...
All of these experiments seem to point strongly towards the notion that spines or synapses (and not entire cells) may be the smallest unit of memory storage in the brain and it may, therefore, be most appropriate to say that the “engram” of a memory is laid down in the set of ...
According to this theory, as fortified by contemporary knowledge, learning activates a small ensemble of brain cells, inducing in these cells persistent physical/chemical changes. In addition, reactivation of these cells by relevant recall cues results in retrieval of the specific memory. The theory ...
We found that reactivation of DG engram cells by contextual cues resulted in a transient enhancement of excitability, which was specific to engram cells, immediately after recall. This rapid but transient change in the state of the engram cell excitability increased the accuracy and efficiency of ...