AAV-Based Bright and Sparse Labeling of Versatile Neurons Adaptable in Cre-Dependent Genetic Backgrounds

Area of Science:

• Neuroscience
• Molecular Biology
• Genetics

Background:

• Sparse labeling is crucial for central nervous system morphological analysis.
• Conventional methods like Golgi-Cox staining and biocytin injection are widely used but have limitations.
• Adeno-associated virus (AAV) technology offers advanced sparse neuronal labeling but faces challenges with specific genetic backgrounds and preparation.

Purpose of the Study:

• To develop a Cre-orthogonal AAV-based sparse labeling method using Supernova technology.
• To enable Cre-independent neuronal labeling compatible with existing genetic tools.
• To provide a straightforward and flexible approach for sparse labeling in diverse neuronal populations.

Main Methods:

• Utilized Flpe recombinase for Cre-independent labeling.
• Employed adeno-associated virus (AAV) vectors with Supernova technology.
• Administered local injections of AAVs into target brain regions in male and female mice.

Main Results:

• Achieved bright and sparse labeling of multiple neuronal types, including cerebellar neurons.
• Labeled neurons were bright enough to visualize fine structures like dendritic spines without immunostaining.
• Demonstrated compatibility with Cre-expressing and floxed genetic backgrounds.

Conclusions:

• The developed method offers a simple, flexible, and effective approach for bright and sparse neuronal labeling.
• This technique is broadly applicable across various genetic backgrounds and readily integrates into existing experimental systems.
• The labeled neurons allow for further genetic manipulation via co-infection with additional viruses.