From neurons to behaviour: dynamics of a memory representation within the hippocampus, and beyond

Hippocampal neuronal activity, described in terms of spatio-temporally organised spike discharge and rhythmic fluctuations of the local field potentials, supports information processing with relevance to memory. However, the circuit-level mechanisms that momentarily define the acquisition, the consolidation or the retrieval of mnemonic information remain somewhat elusive. In this talk, I will present novel findings describing how spectral components nested in individual cycles of the theta-band (4–12Hz) oscillations report transient hippocampal operating modes with complementary mnemonic roles. I will then share some recent work that uncover a circuit motif embedded in the nucleus accumbens that enables the behavioural readout of a hippocampal memory representation. Altogether, these data further highlight how fine-grained neuronal dynamics in the hippocampus and connected circuits promote behaviourally-effective memory.