Drs. Boris Zemelman and Michael Drew, along with Dr. Stephan Martin in the department of Chemistry, received a NIH Brain Initiative grant for their proposal entitled “A viral system for light-dependent trapping of activated neurons”. This project will develop a novel method for identifying and gaining genetic access to transiently active, behaviorally-relevant assemblies of neurons in awake animals. The technique will utilize viral-based labeling of neurons that allows identification activated neurons on the basis of elevated intracellular calcium and then tags them using light. Cell function can then be analyzed in vivo using selective activity manipulation, while cell properties can be examined ex vivo using protein, gene or histological assays. When used in the context of disease states-addiction, depression, anxiety, and many others-this new technique will yield novel cellular targets for clinical intervention.