Neuropathology and applied neurobiology
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Neuropathol. Appl. Neurobiol. · Aug 2006
The olfactory route for cerebrospinal fluid drainage into the peripheral lymphatic system.
Drainage of the cerebrospinal fluid through the olfactory nerves into the nasal lymphatics has been suggested repeatedly. To investigate precisely the morphology of this pathway, India ink was injected into the subarachnoidal space of the rat brain, and samples including the olfactory bulbs, olfactory tracts and the nasal mucosa were observed by light and electron microscopy. Under the dissecting microscope, ink particles were found within the subarachnoid space and along the olfactory nerves. ⋯ These results indicate that the cerebrospinal fluid drains from the subarachnoid space along the olfactory nerves to the nasal lymphatics, which in turn, empties into the cervical lymph nodes. This anatomical communication, thus, allows the central nervous system to connect with the lymphatic system. The presence of this route may play an important role in the movement of antigens from the subarachnoidal space to the extracranial lymphatic vessels, resulting in inducement of an immune response of the central nervous system.