In the central nervous system (CNS), the highly vascularized choroid plexus (CP) produces the cerebrospinal fluid (CSF) and also acts as a blood-CSF barrier (BCSFB). Due to its location in the ventricular system of the brain, the CP can be used by pathogens such as bacteria to enter the CNS by crossing from the blood into the brain. This process, which can lead to meningitis, encephalitis and meningoencephalitis, is usually pr...

The conducting airways are lined by distinct cell types, comprising basal, secretory, ciliated, and rare cells, including ionocytes, solitary cholinergic chemosensory cells, and solitary and clustered (neuroepithelial bodies) neuroendocrine cells. Airway neuroendocrine cells are in clinical focus since they can give rise to small cell lung cancer. They have been implicated in diverse functions including mechanosensation, chemo...