Syn-FLEX-NES-jRGECO1b AAV (Serotype 9)

Syn-FLEX-NES-jRGECO1b AAV (serotype 9) is a viral vector system that combines several advantages, making it suitable for neural circuit research. The adeno-associated virus serotype 9 (AAV9) backbone exhibits excellent neuronal tropism. Compared to other viral vectors, it achieves efficient transduction in multiple brain regions with relatively low immunogenicity. The Syn-FLEX system utilizes a Cre-dependent flip-excision switch, allowing for highly specific expression in target neuronal populations when used in conjunction with Cre driver lines. The jRGECO1b calcium indicator offers higher sensitivity and signal-to-noise ratio compared to earlier GECIs, enabling the detection of neural activity. Its near-infrared fluorescence properties allow for deeper tissue penetration and reduced interference from autofluorescence. The addition of a nuclear export signal (NES) ensures proper localization of the indicator in the cytoplasm for optimal functional imaging.

This versatile tool has broad applications in systems neuroscience research. It can be used for high-resolution functional imaging of specific neuronal populations in behaving animals using techniques such as two-photon microscopy or fiber photometry. Researchers can combine it with retrograde or anterograde tracers to map circuit connectivity. Cre-dependent expression allows for the study of the function of specific cell types within complex neural networks. The improved kinetics and brightness of the jRGECO1b indicator facilitate the detection of single action potentials and subthreshold activity in vivo. These characteristics make this vector particularly valuable for studying neural dynamics in behavioral, sensory processing, learning, and memory paradigms. Other applications include monitoring disease progression in neurological disease models, screening therapeutic interventions, and validating computational models of neural coding.