Increased CSF drainage by non-invasive manipulation of cervical lymphatics

Cerebrospinal fluid (CSF) in the subarachnoid space around the brain drains to lymph nodes in the neck, but the connections and regulation have been challenging to identify1–24. Here we used fluorescent tracers in Prox1–GFP lymphatic reporter mice to map the pathway of CSF outflow through lymphatics to superficial cervical lymph nodes. CSF entered initial lymphatics in the meninges at the skull base and continued through extracranial periorbital, olfactory, nasopharyngeal and hard palate lymphatics, and then through smooth muscle-covered superficial cervical lymphatics to submandibular lymph nodes. Tracer studies in adult mice revealed that a substantial amount of total CSF outflow to the neck drained to…