A major challenge of systems biology is understanding how phenomena at the cellular scale correlate with activity at the organism level. A concerted effort has been made especially in the brain, as scientists are aiming to clarify how neural activity is translated into consciousness and other complex brain activities. One example of the technologies needed is whole-brain imaging at single-cell resolution. This imaging normally involves preparing a highly transparent sample that minimizes light scattering and then imaging neurons tagged with fluorescent probes at different slices to produce a 3D representation.