What does a mouse look like if its tissues are clear and its nerves are fluorescent green? Scientists now have an answer beyond “kind of like an alien.”

The technique to photograph a mouse with see-through tissues and organs and a lit-up nervous system was described in a new paper published in the journal Nature Methods.

The method is called uDisco, and it can follow the start of a neuron’s journey in the animal’s head all the way to the very tip of its extremities without that view being blocked by a pesky ligament or liver. Scientists run an alcohol- and fluorescent protein-filled solvent on and through the body for four days to achieve the transparency and simultaneously light up its nervous system.

Eventually, the researchers said, they hope to use this method to study human brains. It could be especially useful for studying diseases that break down neural connections in the brain such as Alzheimer’s. That’s because current studies of the brain tend to look at sliced sections—but the very act of slicing the brain breaks down some of the neural networks and connections that could hold important information. By making the neurons glow green and the rest of the brain tissue clear, scientists would be able to see through an entirely intact brain.

Check out the New York Times to see more ins and outs of the transparency method, and the pros and cons of other methods trying to achieve similar results.