The CA3 region of the hippocampus is important for rapid encoding of memory. Computational theories have proposed specific roles in hippocampal function and memory for the sparse inputs from the dentate gyrus to CA3 and for the extended local recurrent connectivity that gives rise to the CA3 autoassociative network. Recently, new insight into the operation and plasticity of CA3 circuits has been gained, including the identification of novel forms of synaptic plasticity and their underlying mechanisms, including structural plasticity in the GABAergic control of CA3 circuits. This review also explores experimental links between synaptic plasticity of CA3 circuits and memory which are starting to emerge.
Rebola N, Carta M, Mulle C: Operation and plasticity of hippocampal CA3 circuits: implications for memory encoding. Nature Reviews Neuroscience 18(4): 208-220 (2017).