Pyramidal cells in the hippocampus are part of a small neuronal network that performs computations on external input. The network consists of principal cells and various forms of inhibition: feedback and feed-forward inhibition. Moreover, experimental evidence indicates at least two functionally distinct inhibitory loops: (1) a loop in which O-LM interneurons project to the distal dendrites of pyramidal cells with synapses that have slow kinetics, and (2) a loop in which basket interneurons project to the somata of pyramidal cells with synapses that have fast kinetics. We investigated the effects of these different forms of inhibition, and found that, counterintuitively, inhibition can increase the firing frequency of pyramidal cells.