The Choroid Plexus and Cerebrospinal Fluid System: Roles in Neurodegenerative Diseases

We review the recent advances in the understanding of the roles of choroid plexus (CP), cerebrospinal (CSF), and interstitial fluids (ISF) in neurodegenerative diseases. For several years research in this field has been focusing on neuronal dysfunctions. Recently, there has been a new interest in considering the neuron as part of a larger system also comprising the glia, brain vasculature, and ISF/CSF compartment. Molecular contributions of the CP and astrocyte network in ISF/CSF buffering are reviewed along with their dysfunction in neurodegenerative diseases. In addition to its function in CSF formation and cerebral protection, the CP is also a remarkable place for immune cell trafficking. The CSF could contribute to immune cells maturation during their migrations to the lesion site in the brain tissue. Finally, the CSF is a wonderful window on events occurring in the brain, and an active research is trying to identify the presence of early biomarkers to diagnose neurodegenerative diseases.