The Cre-dependent tracing framework can be expanded to target specific neuronal subtypes or cell types by incorporating cell type-specific promoters into the system. Currently, the framework utilizes the elavl3 promoter for pan-neuronal labeling, but by replacing this promoter with cell type-specific promoters, such as vglut2a for excitatory neurons or gad1b for inhibitory neurons, the tracing can be restricted to specific neuronal subtypes. This modification would allow for more precise circuit mapping and analysis by targeting distinct populations of neurons within the brain. Additionally, the incorporation of multiple Cre-dependent reporters with different fluorophores can enable the simultaneous visualization of multiple neuronal subtypes within the same circuit, providing a comprehensive view of the connectivity patterns in the brain.