Observation of the ciliary movement of choroid plexus epithelial cells Ex vivo

The choroid plexus is located in the ventricular wall of the brain, the main function of which is believed to be production of cerebrospinal fluid.Choroid plexus epithelial cells (CPECs) covering the surface of choroid plexus tissue harbor multiple unique cilia, but most of the functions ofthese cilia remain to be investigated. To uncover the function of CPEC cilia with particular reference to their motility, an ex vivo observationsystem was developed to monitor ciliary motility during embryonic, perinatal and postnatal periods. The choroid plexus was dissected out ofthe brain ventricle and observed under a video-enhanced contrast microscope equipped with differential interference contrast optics. Underthis condition, a simple and quantitative method was developed to analyze the motile profiles of CPEC cilia for several hours ex vivo. Next, themorphological changes of cilia during development were observed by scanning electron microscopy to elucidate the relationship between themorphological maturity of cilia and motility. Interestingly, this method could delineate changes in the number and length of cilia, which peaked atpostnatal day (P) 2, while the beating frequency reached a maximum at P10, followed by abrupt cessation at P14. These techniques will enableelucidation of the functions of cilia in various tissues. While related techniques have been published in a previous report1, the current studyfocuses on detailed techniques to observe the motility and morphology of CPEC cilia ex vivo.