Aquaporins in the central nervous system

In this review, we have tried to summarize most available data dealing with the aquaporin (AQP) family of water channels in the CNS. Two aquaporins ha ve been identified so fat in the CNS, AQP1 and AQP4. AQP1 is restricted to the choroid plexus of the lateral ventricles, which raises a role for this aquaporin in cerebrospinal fluid formation. AQP4 is the predominant water c hannel in the brain and it is more widely distributed than originally belie ved, with a marked prevalence over periventricular areas. In the first part of this review, we examine the complete distribution pattern of AQP4 in th e CNS including its rostro-caudal localization to end with its subcellular location. After discussing scarce data dealing with regulation of aquaporin s in the CNS, we focus in potential roles for aquaporins. Novel recent data highlights very important roles for this aquaporin in the normal and patho logical brain including, among others, role in potassium buffering, body fl uid homeostasis, central osmoreception and development and restoration of b rain edema. (C) 2001 Elsevier Science Ltd. All rights reserved.