This image depicts a mouse brains from a transgenic line that expresses green fluorescent protein (GFP) in neurons that produce the Thy1 protein, which plays a key role in neuronal communication. The bright fluorescence reveals the intricate architecture of the brain’s neuronal network, where countless projections interlace into a structure that visually resembles a vascular system. The sample has been physically expanded to highlight fine structural details. Together, they convey both the scale and beauty of neural connectivity at the whole-organ level.