Neurons (IMAGE) Université de Genève Caption Hippocampal neurons are expressing a protein (in red) that allows one to control neuronal activity with a beam of light. The researchers thus direct the activation of neurons (in green, image on the right). Credit © Pablo Mendez - UNIGE. 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.