Throughout the cortical mantle, distinct inhibitory cell types deliver GABA to specific spatial domains of principal cells at particular times during behaviorally relevant network oscillations. Recent results from the hippocampus of awake mice have revealed emerging principles of the temporal ordering of interneuronal discharges during network oscillations. We will discuss new evidence showing the highly non-homogeneous organization of inhibitory-excitatory microcircuits in the hippocampus is highly selective with respect to the long-distance projection patterns of the heterogeneous pyramidal cell populations. Next, the question of closed-loop optogenetic control of hippocampal pathological activity will be addressed. Finally, we will discuss results from data-driven, full-scale (1:1) computational models of the hippocampus that give us quantitative insights into the roles of the various constituent cell types in ensemble network activities.