[초청강연] Stable memory with dynamic engram

Title: Stable memory with dynamic engram

Memories are thought to be encoded and stored in a collection of cells sparsely
distributed across wide brain areas. There has been a controversy about where such
cell ensembles are stable. In my talk, I will present a recent study in mice from our
lab that demonstrates a shift in cell ensembles supporting a memory in the lateral
amygdala by relearning of fear conditioning. By re-learning, originally recruited cell
ensembles become dispensable for memory retrieval accompanied with a reduction
of synaptic transmission and loss of dendritic spines. Despite the decreased
connectivity, direct activation of these neurons still can induce memory recall. Cell
ensembles active during re-learning within the lateral amygdala are required for
retrieval of the re-learned fear memory, indicating a shift in cell ensembles by re-
learning. These results support a dynamic nature of cell ensembles supporting
memory.