Gamma (25-60 Hz) oscillations are associated with cognitive processing in the cortex. They can be generated by excitation of populations of mutually inhibitory, interconnected interneurons. Such oscillations can entrain the firing patterns of excitatory projection neurons and have been shown both to facilitate the synchronization of spatially separate populations of neurons and mediate changes in synaptic strength that alter the ability of populations to synchronize. Here we demonstrate that gamma oscillations also act as a powerfully selective gate for trains of afferent inputs to an oscillating area, based on the 'precise timing of inputs' as opposed to their absolute magnitude or frequency.