Meningeal lymphatic vessels

The meningeal lymphatic vessels (or meningeal lymphatics) are a recently discovered network of conventional lymphatic vessels located parallel to the dural sinuses and meningeal arteries of the mammalian central nervous system (CNS). As a part of the lymphatic system, the meningeal lymphatics are responsible for draining immune cells, small molecules, and excess fluid from the CNS and into the deep cervical lymph nodes.

While it was initially believed that both the brain and meninges were devoid of lymphatic vasculature, a recent study by Antoine Louveau and Jonathan Kipnis at the University of Virginia, submitted in October 2014, and another confirming the discovery, by Aleksanteri Aspelund and Kari Alitalo at the University of Helsinki submitted in December 2014, identified and described the basic biology of the meningeal lymphatics using a combination of histological, live-imaging, and genetic tools. In general, their work is thought to extend that of the Danish neuroscientist Maiken Nedergaard in identifying the pathway connecting the glymphatic system to the meningeal compartment.

Currently, the role that the meningeal lymphatics play in neurological disease is yet to be explored. However, there is some speculation that they may contribute to autoimmune and inflammatory diseases of the CNS due to their role in connecting the immune and nervous systems.

In peripheral organs, lymphatic vessels are responsible for conducting lymph between different parts of the body. In general, lymphatic drainage is important for maintaining fluid homeostasis as well as providing a means for immune cells to traffic into draining lymph nodes from other parts of the body, allowing for immune surveillance of bodily tissues.

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