Neurogenesis and multiple plasticity mechanisms enhance associative memory retrieval in a spiking network model of the hippocampus

摘要: Hippocampal CA3 is crucial for the formation of long-term associative memory. It has a heavily recurrent connectivity, and memories are thought to be stored as memory engrams in CA3. However, despite its importance storage retrieval, spiking network models date relatively small-scale, exist only proof-of-concept models. Specifically, how neurogenesis dentate gyrus affects encoding retrieval not studied such Our work first develop biologically plausible neural model hippocampal with at least an order-of-magnitude more neurons than previous also investigate effect on retrieval. Using model, we show that recently developed plasticity good Next, properties related neuronal death enhance In particular, without neurogenesis, increasing number recruited by each new stimulus, resulting corresponding increase inhibition poor encoded. Neurogenesis, other hand, maintains per enables recent memories, while forgetting older ones. suggests structural (provided apoptosis) required hippocampus when overloaded; synaptic alone does suffice. The above results obtained from exhaustive study different parameters.