Cyclic adenosine monophosphate (cAMP) is an important intracellular messenger that plays a critical role in the development of the central and peripheral nervous system. However, the mechanisms of action of cAMP in the nervous system development are poorly understood and there are currently no suitable methods to visualize cAMP in the cells of living animals. Here I propose to bring new insights into cAMP signaling and dynamics in the nervous system by constructing a reporter that will generate a fluorescent signal only in the presence of cAMP, which will allow the visualization of cAMP in many different species and cell types. I will take advantage of the transparent and genetically tractable zebrafish, an excellent model to study the development in vivo, to test the efficiency of the reporter. In addition, I will combine imaging with the reporter and gene expression analyses to measure how cAMP levels regulate gene expression in cells of the nervous system that are regulated by cAMP. This project intends to gain a deeper understanding of cAMP signal and dynamics in the development of the vertebrate nervous system by taking advantage of an advanced tool to image cAMP.