Key questions: What is the relative contribution of excitation and inhibition in firing cortical neurons, for example in response to a sensory stimulus? Despite the simplicity of this question, one factor that has limited our understanding of how the excitation-inhibition ratio influences cortical processing is the paucity of in vivo intracellular recording analyzing the relative contribution of the two opposing conductances during sensory stimulation. High-quality, whole-cell voltage clamp recordings are still the gold standard for distinguishing excitatory and inhibitory conductances within individual cells; further improvements of this method for in vivo studies, particularly in awake, behaving animals, are essential.
