Labeling and imaging of neurons with a genetically encoded autonomous bioluminescence system.

The bacterial bioluminescence system, consisting of a luciferase and enzymes for intracellular luciferin synthesis, enables autonomous bioluminescence imaging of mammalian cells. Its continuous light emission without the need for exogenous substrate administration makes this system particularly well-suited for the long-term imaging of living cells. An additional feature is its dependence on metabolic energy, allowing the monitoring of cellular energy status and vitality. However, the system’s relatively low brightness and the requirement of six different genes complicate cellular labeling and imaging. Here, we employed a combination of recombinant adeno-associated viruses containing the involved genes to achieve both bright and cell type-specific bioluminescent labeling of neurons. The high light output obtained with the developed viruses enabled the detailed visualization of individual neurons. Furthermore, monitoring of bioluminescence emission in the presence of neurotoxic agents allowed the observation of cellular decline in models of neurodegenerative diseases. The autonomous light production realized with our labeling approach thus provides a promising tool for investigating neurodegeneration, facilitating continuous and real-time cellular monitoring.