The Choroid Plexus

Abstract

The choroid plexus (CP) produces cerebrospinal fluid (CSF) and forms a portion of the physical structure of the CSF-blood barrier. More recently, the CP been implicated in other basic aspects of neural functioning, such as surveying the chemical and immunological status of the brain, detoxifying the brain, secreting a nutritive cocktail of polypeptides for neuronal function and survival, and participating in repair processes following trauma. The CP also has a role in maintaining the extracellular milieu of the brain by actively modulating the chemical exchange between the CSF and brain parenchyma and by secreting numerous growth factors into the CSF. Preclinical and clinical studies in aging and neurodegeneration demonstrate anatomical and physiological changes in the CP, suggesting effects not only in normal development and pathological conditions, but also in potential endogenous repair processes following trauma. CP dysfunction in central nervous system (CNS) diseases, and the endogenous secretion of growth factors, indicates that transplantable CP might enable delivery of growth factors to the brain while avoiding the conventional molecular and genetic alterations associated with modifying cells to secrete selected products. Thus, this enables the possibility of replacing or transplanting CP as a means of treating acute and chronic brain diseases. This chapter focuses on the various functions of the CP, how these functions are altered in aging and neurodegeneration, and recent demonstrations of the therapeutic potential of transplanted CP for neural trauma.