Trying to fit it all in? There’s a trick to it, even in 24 dimensions.

Recent discoveries of glymphatics and meningeal lymphatics have redefined our understanding of CNS immunosurveillance. Kim and Kipnis illustrate how the clearance of brain-derived antigens creates an “immune code” that, when presented by meningeal antigen-presenting cells, instructs T cells to safeguard neural homeostasis. They review how inflammation, aging, and neurodegeneration disrupt this finely tuned process and highlight emerging therapeutic opportunities.