Why is the human brain so difficult to understand? When scientists uncover basic science principles of the neuron, how does that scale up to system-wide understanding or to clinical treatments? The instruments that help us investigate the function of an individual neuron are very different from the instruments needed to parse subjective human experience. This notion of scale, in both time and space, will be integral to exploring the obstacles of neuroscience research and to surveying the neurobiotech tools that help answer these difficult questions.