Mouse brain lymphatic vessels

The lymphatic system plays a vital role in immune function and waste removal, yet its involvement in the brain has remained largely unexplored. This study provides compelling evidence of lymphatic vessels in the mouse brain, specifically in the cortex, thalamus, and hippocampus. Using confocal microscopy, western blotting, and real-time PCR, lymphatic vessels were identified by the markers Lyve1, Prox1, and VEGFC. Paraffin-embedded brain slices from wild-type Balb/C mice, stained with antibodies against Lyve1, CD31, and CD34, revealed the presence of these vessels through detailed 2D and 3D imaging. Notably, a coiled 3D structure of lymphatic vessels was observed in the hippocampus, suggesting a complex lymphatic drainage network critical for brain homeostasis. Western blot analysis confirmed the expression of lymphatic markers Lyve1, Prox1, and VEGFC, along with endothelial markers CD31 and CD34. Real-time PCR demonstrated significant mRNA expression of these markers, further supporting their presence. This study uniquely integrates protein ex-pression analysis and gene expression profiling to characterize the brain's lymphatic system. The findings reveal a functional lymphatic system extending from the meninges into deeper brain regions, challenging the long-standing belief that the brain lacks lymphatic vessels. This finding marks a significant advancement in neuroimmunology, providing new insights into immune system involvement in the central nervous system. It highlights potential pathways for clearing macromolecules and immune cells, offering promising therapeutic strategies for brain diseases.