One potential limitation of the viral tracing approach is the possibility of non-specific labeling, such as the transneuronal spread to non-neuronal cells like glia. This can complicate the interpretation of circuit mapping results and may lead to inaccuracies in the connectivity patterns identified. To address this limitation, the viral tracing approach could be combined with cell type-specific genetic tools, such as the Cre-dependent tracing system described in the study. By using cell type-specific promoters and reporters, the tracing can be restricted to the desired neuronal populations, reducing the likelihood of non-specific labeling. Additionally, the optimization of viral strains and helper proteins, as demonstrated in the study, can improve the efficiency and specificity of the tracing, enhancing the reliability and interpretability of the circuit mapping results.