High-Resolution 3D reconstruction and visualization of normal adrenal vasculature and sympathetic nerves in mice.

PURPOSE: The vasculature and sympathetic nervous system are critical for adrenal homeostasis, but conventional imaging limits characterization of the adrenal glands’ 3D structure. This study aimed to delineate the mouse adrenal glands’ 3D architecture and key component spatial relationships via advanced tissue-clearing imaging. METHODS: We used FDISCO (fluorescence-preserving 3D imaging of solvent-cleared organs) for whole-mouse adrenal imaging, complemented by 2D cortical and medullary marker co-staining and 3D density quantification. RESULTS: 3D imaging revealed three key features of mouse adrenal glands. First, sympathetic nerves primarily surround adrenal blood vessels, forming a close spatial association with the vascular network. Second, the cortex and medulla were tightly interwoven. Third, we characterized the 3D vasculature of adrenocortical accessory nodules, which are devoid of medullary components and have significantly higher vascular density than the cortex. CONCLUSIONS: We defined mouse adrenal 3D architecture, providing novel insights and highlighting FDISCO’s value for adrenal research.