Memory shapes everyday behaviour by engaging complex patterns of neuronal activity distributed across brain networks, including the hippocampus. But what features of neural activity underlie memory-guided behaviour? In this talk, I will explore how spatio-temporally organized spike trains of neuronal ensembles and rhythmic fluctuations in local field potentials contribute to the internal processing of mnemonic information. Drawing on cross-species findings, I will highlight network-level dynamics that support memory across both rodent and human brains. Importantly, I will show how organizational principles and analytical frameworks developed in rodent models are now being leveraged to uncover the oscillatory circuitry underlying human memory. These insights reveal how fine-grained neural dynamics, distributed across the hippocampus and its partner circuits, orchestrate memory-guided behaviour in the mammalian brain.