Head of a zebrafish larva (IMAGE) University of Bonn Caption The transparent nature of these animals allows their brain to be identified under the microscope. It is colored green in the image because it produces a dye that lights up green during neuron activity. Image: Portugues Laboratory/TUM Credit Image: Portugues Laboratory/TUM Usage Restrictions This image may be used together with the press release. License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.