High-pressure Golgi neuronal staining for X-ray whole-brain imaging

Whole-brain imaging has revolutionized neuroscience research, providing comprehensive insights into neural networks across the entire brain. This powerful approach has greatly advanced our understanding of brain functions and the mechanisms underlying various diseases. One primary challenge in whole-brain imaging technology is to achieve high-resolution observation of neural networks at large scales. Although Golgi method allows labeling random neurons in their entirety in the brain, visualizing individual dendritic trees, and tracing long-distance axonal projections, the lengthy processing time pose a limit on its use, i.e., staining a mouse whole-brain sample of just 300 mm³ takes over two weeks. Here, we developed a rapid staining technique for whole-brain neurons using high-pressure assisted Golgi (HP Golgi). This method significantly reduced the staining time for mouse whole-brain neurons from 16 days to only 4 days. We demonstrated the broad applicability of the HP Golgi method across various model organisms, achieving whole-brain neuronal staining in zebrafish, mice, and rats. Further, we successfully performed rapid staining of hippocampal neurons in an intact pig brain, which is difficult to achieve with the classic Golgi-Cox method. We also demonstrated that the combination of the HP Golgi method with synchrotron-based X-ray microscopy for high-resolution imaging of whole-brain neurons in mice. This HP Golgi method enables fast and high-resolution neuronal imaging in large model organisms, showcasing its broad applicability for diverse applications.