Ageing choroid plexus-cerebrospinal fluid system

The impact of ageing on the choroid plexus (CP)-CSF circulatory system has largely been un-investigated, or has been of interest only in relation to n eurological disease. This paper reviews the evidence for age-related change s to the CP-CSF system and compares changes with disease states where appro priate. The changes discussed include reduced ion transport capabilities, e vidence for oxidative stress, altered hormone interactions, decreased CSF s ecretion rates in animal models and the contradictory nature of human data, reduced clearance of protein from CSF, and slower fluid turnover. The pote ntial impacts of these changes are highlighted, including the possibility o f reduced resistance to stress insults and slow clearance of toxic compound s from CSF with specific reference to amyloid peptide. Other impacts may in clude the reduced ability of CSF to act as a circulating medium for hormone and growth factors to reach their brain targets, and reduced homeostasis o f CSF nutrients (amino acids, vitamins), which might influence brain inters titial fluid homeostasis. (C) 2001 Wiley-Liss, Inc.