Overview
- A March 5 Cell Press Blue paper reports that tanycytes move tau from cerebrospinal fluid into pituitary portal capillaries, enabling entry into the bloodstream.
- In mice given fluorescent human tau, signal localized to tanycytes tracing a route from the third ventricle to the pituitary vasculature before reaching blood.
- Experimental blockade of tanycytic vesicular transport in rodents sharply reduced CSF-to-blood tau efflux and intensified tau pathology.
- Human data from 86 Alzheimer’s patients versus 91 controls showed decreased plasma-to-CSF ratios of total tau and p‑tau181 in the patient group.
- Postmortem Alzheimer’s brains displayed fragmented tanycyte processes with vesicular-transport–related transcriptomic alterations, pointing to impaired clearance, while authors note the need for larger, longitudinal cohorts and better disease models before translation.