Two-photon Microscope (IMAGE) University of North Carolina at Chapel Hill Caption Spencer Smith built his own two-photo microscope, which allows him to take photos of neurons firing in the brains of mice. Credit Spencer Smith Usage Restrictions None License Licensed 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.