The secret of capturing exquisite brain images with a new generation of custom-built microscopes is revealed today in Nature Methods. The new microscopes, known as mesoSPIMs, can image the minute detail of brain tissue down to individual neurons, and can uncover the 3-D anatomy of entire small organs faster than ever before. MesoSPIMs provide new insights into brain and spinal cord organization for researchers working to restore movement after paralysis or to investigate neuronal networks involved in cognition, pleasure or drug addiction.