choroid plexus epithelial cell obsolete choroid plexus cell true Choroid plexus cells, also called choroidal cells, are specialized epithelial cells located in the choroid plexus of the brain. Situated adjacent to the pia mater layer bordering cerebrospinal fluid-filled cavities, these cells play pivotal roles in maintaining brain health and are integral to the central nervous system. A primary function of choroid plexus cells is the production of cerebrospinal fluid (CSF), a clear fluid crucial for cushioning the brain and spinal cord, delivering nutrients, and removing waste products. Operating as a filtration system, these cells generate CSF from blood plasma, regulating the brain environment by selectively allowing certain molecules to pass and filtering out harmful substances. Furthermore, choroid plexus cells contribute significantly to the central nervous system's immune response. Releasing various immune molecules and interacting with immune cells, they provide an additional line of defense against potential pathogens or harmful substances. Their central location in the brain's ventricles positions them as key players in maintaining brain homeostasis. Research links abnormalities in choroid plexus cells to neurodegenerative diseases like Alzheimer’s and disorders such as schizophrenia, underscoring their crucial role in preserving brain health. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) OBSOLETE. A cell that is part of the choroid plexus. https://cellxgene.cziscience.com/cellguide/CL_4023073