Hippocampal network oscillations - recent insights from in vitro experiments

•Isolated cortical structures generate similar oscillations to those recorded in vivo.•We review recent insights into network oscillations gleaned from hippocampal slices.•The importance of GABAergic interneurons for these oscillations has been confirmed.•Multiple independent gamma oscillation generators have been identified.•Better understanding of spatial and temporal coupling between oscillations is needed.

Network oscillations are present throughout the mammalian brain. They are important for certain cognitive functions, such as learning and memory. The hippocampus exhibits prominent oscillations similar to those seen in other parts of the cortex. Due to its highly organised lamellar structure, ex vivo and in vitro preparations from the hippocampus have provided experimental models within which to study network oscillations. As such, experiments in hippocampal slices continue to progress our understanding about both the mechanisms and functions of cortical network oscillations. Here, advances from the past two years are summarised, and the current state of the field discussed.