Real-time monitoring of cyclic nucleotide signaling in neurons using genetically encoded FRET probes

Signaling cascades involving cyclic nucleotides play key roles in signal transduction in virtually all cell types. Elucidation of the spatiotemporal regulation of cyclic nucleotide signaling requires methods for tracking the dynamics of cyclic nucleotides and the activities of their regulators and effectors in the native biological context. Here we review a series of genetically encoded FRET-based probes for real-time monitoring of cyclic nucleotide signaling with a particular focus on their implementation in neurons. Current data indicate that neurons have a very active metabolism in cyclic nucleotide signaling, which is tightly regulated through a variety of homeostatic regulations.