Dopamine Neurons Labeled with Green Fluorescent Protein (image) Salk Institute Share Print E-Mail Caption Blue indicates cell nuclei, green indicates dopamine neurons labeled with green fluorescent protein. Credit Salk Institute Usage Restrictions with credit and related coverage. Share Print E-Mail 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.