Meningeal lymphatics are lymphatic vessels that drain large molecules in the central nerve sheath. A recent mouse study published online in the journal Nature suggests that meningeal lymphatic dysfunction may exacerbate Alzheimer’s disease and age-related cognitive dysfunction.
Early researchers found lymphatic vessels in the meninges of rodents, non-human primates, and humans, but they determined their function in the central nervous system and their role in central nervous system diseases. Jonathan Kipnis and colleagues demonstrated that meningeal lymphatics can drain the large molecules of the central nervous system cerebrospinal fluid and interstitial fluid into the cervical lymph nodes.
Researchers have discovered that damage to lymphoid function in the meninges of adult and juvenile mice can lead to impaired learning and memory. In addition, the meningeal lymphoid function of old mice is severely impaired or causes some age-related cognitive dysfunction. After the old mice received vascular endothelial growth factor C treatment, meningeal lymphatic vessels can clear the macromolecular cerebrospinal fluid and tissue fluid in the brain, and their learning and memory abilities are also improved.
In the transgenic mouse model of Alzheimer's disease, impaired meningeal lymphatic function promotes the deposition of amyloid in the meninges. This is very similar to the pathological manifestations of the meninges of human Alzheimer's disease. Researchers believe that increasing meningeal lymphatic function can prevent or delay age-related neurological diseases.