The skull-brain axis!
The skull marrow is a distinct and specialized hematopoietic niche
Recent studies have described the presence of skull channels, or skull– meninges connections, forming a direct anatomical and functional pathway for the trafficking of immune cells and cerebrospinal fluid between the skull and dura.
Skull marrow directly supplies immune cells to the meninges under homeostasis, particularly monocytes, neutrophils, and B cells at different stages of differentiation.
The skull–brain axis is dynamically engaged in pathology, and skull-derived immune cells rapidly mobilize through skull channels to the meninges and brain.
Age-related expansion of the skull marrow, alterations in skull bone architecture, and increased skull inflammation observed in Alzheimer’s and Parkinson’s diseases all suggest a link between skull–meninges communication, inflammaging, and cognitive decline.
https://www.cell.com/trends/immunology/fulltext/S1471-4906(26)00068-2
